th
29 Annual Graduate
Research Conference
29th Annual Graduate Research Conference
Friday, April 20, 2007
1
29th Annual UMB Graduate
Research Conference
CONTENTS
Page
3
Forward
4
Keynote Speaker Biography
5
Schedule of Events
7
Abstracts
52
Index
29th Annual Graduate Research Conference
Friday, April 20, 2007
2
29th Annual Graduate Research Conference
Forward by GSA Executive Board
Welcome to the 29th annual Graduate Research Conference (GRC)! The Graduate Student
Association of the University of Maryland, Baltimore (UMB) has been dedicated to this project since
the beginning of the school year. Each year, the GRC familiarizes graduate students with preparing
for scientific meetings, as well as the opportunity to present results of their ongoing research in an
interdisciplinary setting to peers, faculty members, and the UMB community at large.
This year we have restructured the GRC to allow for an even more interdisciplinary
conference which categorizes research across fields and even schools. We hope this restructure will
enrich the student’s experience as well as challenge them to apply their work to a new and broader
audience. Over 100 students from across the UMB campus will present their work as either poster or
oral presentations at this GRC, and we would like to thank each of the presenters for their time and
effort to formally communicate their achievements – we commend your hard work and devotion to
your science.
The Graduate Student Association Executive Board would like to thank everyone who has
contributed to this year’ conference. Specifically, we would like to acknowledge Dr. Malinda Orlin,
Vice President for Academic Affairs and Dean of the UMB Graduate School; Dr. Erin Golembewski,
Assistant Dean of the UMB Graduate School; Tanya Tucker, Communications Manager and all the
members of the UMB Graduate School office.
Additionally, we would like to thank the faculty members who have volunteered their time to
serve as judges and mentors -- your dedication to the advancement of your students here today, and
everyday, is greatly appreciated. Thank you to the GSA Departmental Representative volunteers for
your dedication, energy, and initiative.
Finally, we would like to acknowledge the Graduate Program in Life Sciences (GPILS) and Dr.
McCarthy for sponsoring our keynote speaker Dr. Alan Leshner, who we are privileged to have here
today.
We hope that you enjoy your experience at this year’s GRC. We have worked hard to make
the day as enjoyable and informative as possible. We invite you to participate fully in this year’s
conference and we look forward to welcoming you back next year. It has truly been a privilege and
honor to provide a colloquium for all graduate students of the UMB community to present their
achievements.
UMB Graduate Student Association Executive Board
Satish Valluri, President
Justin Kerr, Vice-President
Jade Bernstein, Treasurer
Michelle Weber, Secretary
Carrianne Jung, Graduate Council Representative
29th Annual Graduate Research Conference
Friday, April 20, 2007
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29th Annual Graduate Research
Conference Keynote Speaker
DR. ALAN I. LESHNER
American Association for the Advancement of
Science, Chief Executive Officer
Executive Publisher, Science
Dr. Leshner has been Chief
Executive Officer of the American
Association for the Advancement of
Science (AAAS) and Executive Publisher
of the journal Science since December
2001. AAAS was founded in 1848 and is
the world's largest, multi-disciplinary
scientific and engineering society.
Before coming to AAAS, Dr.
Leshner was Director of the National
Institute on Drug Abuse (NIDA) from
1994-2001. One of the scientific institutes
of the U.S. National Institutes of Health,
NIDA supports over 85% of the world's
research on the health aspects of drug
abuse and addiction.
Before becoming Director of
NIDA, Dr. Leshner had been the Deputy
Director and Acting Director of the
National Institute of Mental Health. He
went to NIMH from the National Science
Foundation (NSF), where he held a
variety of senior positions, focusing on
basic research in the biological, behavioral
and social sciences, science policy and
science education.
Dr. Leshner went to NSF after 10
years at Bucknell University, where he was
Professor of Psychology. He has also held
long-term
appointments
at
the
Postgraduate Medical School in Budapest,
Hungary; at the Wisconsin Regional
Primate Research Center; and as a
Fulbright Scholar at the Weizmann
Institute of Science in Israel. Dr. Leshner
is the author of a major textbook on the
relationship between hormones and
behavior, and has published over 150
papers for both the scientific and lay
communities on the biology of behavior,
science and technology policy, science
education, and public engagement with
science.
Dr.
Leshner
received
an
undergraduate degree in psychology from
Franklin and Marshall College, and M.S.
and Ph.D. degrees in physiological
psychology from Rutgers University. He
also holds honorary Doctor of Science
degrees from Franklin and Marshall
College and the Pavlov Medical University
in St. Petersburg, Russia. Dr. Leshner is
an elected fellow of AAAS, the National
Academy of Public Administration, the
American Academy of Arts and Sciences,
and many other professional societies. He
is a member of the Institute of Medicine
of the National Academies of Science.
The U.S. President appointed Dr. Leshner
to the National Science Board in 2004,
and he represents AAAS on the U.S.
Commission for UNESCO.
29th Annual Graduate Research Conference
Friday, April 20, 2007
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SCHEDULE OF EVENTS
29TH Annual Graduate Research Conference
Friday, April 20, 2007
University of Maryland Baltimore
8:30-9:30am
BREAKFAST & REGISTRATION
9:30-12:00pm
MORNING SESSION
12:00-1:00pm
LUNCH
1:00-3:30pm
AFTERNOON SESSION
4:00-5:00pm
DR. ALAN LESHNER, KEYNOTE ADDRESS:
THE EMERGING CLIMATE FOR SCIENCE AND SOCIETY
5:00-6:00pm
RECEPTION/AWARDS
29th Annual Graduate Research Conference
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Abstracts
29th Annual Graduate Research Conference
Friday, April 20, 2007
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1. Mtr4p: AN INTIMATE PLAYER IN
EUKARYOTIC NUCLEAR RNA
PROCESSING
Jade Bernstein, Eric Toth
Morning; Oral Presentation; HSFII 241
alternative
splicing
and
post-translational
modifications. We have recently demonstrated that an
increase in the surface expression of CD44 in
response to over expression of OPN stimulated
prostate cancer cell (PC3/OPN) migration to a
greater extent as compared with untransfected PC3
control cells (Desai et al., 2007; Mol. Cancer, IN
Press). OPN and CD44 are implicated in the
tumorigenicity of several cancer cell types. We have
attempted to identify the isoforms expressed in PC3
by reverse transcription-PCR method. At the mRNA
level, we have detected the presence of CD44
isoforms v2 to v10 in PC3 cells. CD44 isoforms v3
and v4 were noticeably upregulated at the
transcriptional level by OPN over expression. We
have extended our studies to determine the regulatory
mechanisms involved in prostate cancer cell
migration. Untransfected PC3, PC3/OPN, and
OPN-null PC3 (PC3/siRNA) cells were used for
these experiments. OPN over-expression increases
the proliferation of PC3 cells. Immunostaining
analyses revealed colocalization of CD44 and MMP-9
on the surface of PC3 cells. This colocalization is
increased in PC3/OPN cells. Zymography analysis
revealed upregulation of MMP-9 activity in
PC3/OPN cells. A significant inhibition in the MMP9 activity was observed in PC3/OPN cells treated
with an antibody to CD44. Our observations suggest
a role for CD44 in the activation of MMP-9 and cell
migration. Based on our observations, we suggest that
CD44 could be considered as an anti-cancer target.
Nuclear RNA processing is responsible for the
creation of accurate RNA species from extended
precursor mRNAs, tRNAs, rRNAs, snRNAs, and
snoRNAs. The goal of this research is to determine
Mtr4ps involvement in RNA processing, and the
interactions that take place with the putative RNA
binding and shuttling components. Nuclear RNA
processing is centered around the exosome, a
complex which functions to process nuclear RNA
precursors and degrade aberrant RNAs in the nucleus.
The yeast exosome includes a putative core of 6
components, Rrp41p, Rrp42p, Rrp43p, Rrp45p,
Rrp46p and Mtr3p, as well as 6 additional
components, Rrp4p, Rrp6p, Rrp40p, Rrp44p, Csl4p
and Mtr4p. Mtr4p has been described as a helicase
based on the presence of the 7 Superfamily 2 helicase
motifs within its sequence. The hypothesis of this
work is that Mtr4p is a well conserved RNA helicase
involved in eukaryotic nuclear RNA processing by
targeting aberrant and precursor RNAs to the RNA
binding and shuttling components of the exosome.
This hypothesis is based on preliminary data showing
Mtr4p to be an RNA helicase which interacts with
some of the exosome components. Based on these
observations the experimental focus of this work is to
elucidate the functions of Mtr4p and its proteolytic
fragments, as a helicase and targeting protein. Focus
will also be put on determining how Mtr4p interacts
with the exosome members responsible for RNA
binding and shuttling of RNA into the exosome core.
3. HIV INFECTION DESTABILIZES A
TARGETED SUBSET OF THE
GAMMADELTA T CELL REPERTOIRE
Andrew M. Hebbeler, Nadia Propp, Jean S.
Cummings, Cristiana Cairo and C. David Pauza
Morning; Oral Presentation; HSFII 241
2. MECHANISMS OF CD44 AS METASTATIC
PRINCIPLES IN PROSTATE CANCER
CELLS
Bhavik Desai, Tao Ma, Meenakshi Chellaiah
Morning; Oral Presentation; HSFII 241
A process of chronic, positive selection by ubiquitous
antigens skews the adult human Vg2 repertoire
toward longer chain lengths due to specific selection
for the Vg2-Jg1.2 rearrangment, and represent 75 ±
13% of the healthy adult Vg2 repertoire. Human
Immunodeficiency Virus (HIV) infection actively
depletes the Vg2-Jg1.2 population even though these
Osteopontin (OPN) is a glycoprotein that binds to
various integrins and CD44 variants. CD44 variant
molecules are encoded by a single gene and varied by
29th Annual Graduate Research Conference
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cells lack the CD4 receptor and are poor targets for
HIV infection. Here, we summarize longitudinal
studies on Vg2 T cells from 16 HIV-infected subjects
that were treated with HAART and successfully
suppressing viral replication. We used spectratype and
CDR3 sequences to assess the complexity and
stability of the Vg2 repertoire in HIV-infected viral
suppressors and healthy, HIV-negative controls.
These results suggest that HAART duration has little
effect on the recovery of Jg1.2 if the starting
repertoire is severely depleted of Vg2-Jg1.2-TCR
expressing cells. These data are definitive in showing
the specific depletion of Vg2-Jg1.2 chains during HIV
infection, even as other Vg2-J segment
rearrangements are preserved. Although repertoire
conservation was observed in some HIV+
individuals, stability was confined largely to receptors
expressing Vg2-Jg rearrangements other than Vg2Jg1.2. In most cases, specific Vg2-Jg1.2 sequences in
HIV+ individuals were unstable and not observed in
subsequent specimens collected at 6 monthly intervals
for a 2 year period. Other pathogens are associated
with transient depletion of Vg2-Jg1.2+ cells, but HIV
drives this subset to exhaustion and recovery is not
possible in advanced disease, despite long-term
effective suppression of viremia.
a candidate gene approach, NUP98, located at
11p15.5, was a strong candidate gene based on
chromosomal location and previous oncogenic
association with AML. We constructed a bacteria
artificial chromosome (BAC) probe set containing the
telomeric and centromeric portions of NUP98 and
demonstrated its involvement in the translocation.
NUP98 is one of the most promiscuous fusion
partner genes in hematological malignancies with
more than 20 different fusion partners on various
chromosomes. Next we identified the breakpoint
location and fusion partner gene located on
chromosome 17p by performing breakpoint mapping
with a series of BAC probes between p53 and LIS1.
RT-PCR and sequence analysis of the breakpoint
junction revealed a novel in-frame fusion of NUP98
exon 13 with PHF23 exon 4. PHF23 is an
uncharacterized gene encoding a protein containing a
plant homeodomain (PHD) which is found in
proteins that may mediate chromatin remodeling in
control of gene expression. We hypothesize that
NUP98 fusion proteins may function as aberrant
transcription factors. Future directions include
functional analyses of the NUP98-PHF23 fusion gene
consisting of transformation assays, differentiation
analysis and identification of potential interacting cofactors.
4. IDENTIFICATION AND
CHARACTERIZATION OF A CRYPTIC 11;17
TRANSLOCATION RESULTING IN A
NOVEL NUP98-PHF23 FUSION IN ACUTE
MYELOID LEUKEMIA
Jocelyn C. Reader, JoAnn S. Meekins, Ivana Gojo, Yi
Ning
Morning; Oral Presentation; HSFII 241
5. THE CHEMOTHERAPEUTIC AGENT, 5,6DIMETHYLXANTHENONE-4-ACETIC ACID
POTENTLY AND SPECIFICALLY
ACTIVATES THE TBK1-IRF3 SIGNALING
AXIS
Zachary J. Roberts, Nadege Goutagny, Katherine A.
Fitzgerald, Himanshu Kumar, Taro Kawai, Shizuo
Akira, and Stefanie N. Vogel
Morning; Oral Presentation; HSFII 241
Chromosomal abnormalities on 17p are associated
with a variety of leukemias. We identified an acute
myeloid leukemia (AML) patient presenting with a
possible abnormality on 17p by standard karyotype
analysis. A deletion was expected; however,
fluorescence in situ hybridization (FISH) with a p53
probe revealed a normal signal pattern. FISH analysis
with a LIS1 sub-telomeric probe revealed a cryptic
balanced 11;17 translocation that is novel in AML.
Our goal is to characterize the translocation. Utilizing
Vascular disrupting agents (VDA) represent a novel
approach to the treatment of cancer, resulting in
collapse of tumor vasculature and tumor death. 5,6Dimethylxanthenone-4-acetic acid (DMXAA) is a
VDA currently in advanced Phase II clinical trials, yet
its precise mechanism of action is unknown despite
extensive preclinical and clinical investigations. The
data presented herein demonstrate that DMXAA is a
29th Annual Graduate Research Conference
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novel and specific activator of the TBK1-IRF-3
signaling pathway. DMXAA treatment of primary
murine macrophages resulted in robust IRF-3
activation, a ~750-fold increase in IFN-b mRNA and,
in contrast to the potent Toll-like receptor 4 (TLR4)
agonist, lipopolysaccharide (LPS), signaling was
independent of mitogen-activated protein kinase
(MAPK) activation and elicited minimal NF-kBdependent gene expression.
DMXAA-induced
signaling was critically dependent on the IRF-3
kinase, TBK1, and IRF-3 itself, but MyD88-, TRIF-,
IPS-1/MAVS-, and IKKe-independent, thus
excluding all known TLRs and cytosolic helicase
receptors as possible DMXAA receptors. The
relevance of these findings was confirmed in vivo,
where DMXAA-induced tumor growth restriction
was observed in wild-type mice but not IFN-bdeficient animals. Taken together, these findings
detail a novel pathway for TBK-1-mediated IRF-3
activation and provide new insights into the
mechanism of this new class of chemotherapeutic
drugs.
and in the effects of these interactions on DNA ligase
I catalytic activity. Moreover, we show that hRad17
preferentially interacts with dephosphorylated DNA
ligase I and that there is an increased association of
DNA ligase I with hRad17 in S phase following either
DNA damage or replication blockage. Since the
increased association of hRad17 and DNA ligase I
occurs concomitantly with DNA damage-induced
dephosphorylation of chromatin-associated DNA
ligase I, our results suggest that the association of
DNA ligase I with the checkpoint and replicative
clamp loaders is regulated by post translational
modification of DNA ligase I.
7. THE ROLE OF OSTEOPONTIN IN
CANCER PROGRESSION AND BONE
METASTSIS
Brian Robertson, Meena Chellaiah
Morning; Oral Presentation; HSFII S600
Osteopontin interaction with adhesion receptors
such as integrins and CD44 mediates many cellular
processes, including cell adhesion, migration,
proliferation, and survival. The role of OPN in cancer
progression is of increasing interest as recent studies
have noted that OPN is overexpressed in breast,
prostate, and pancreatic cancers. Constitutive
activation of Akt is frequently observed in many types
of human cancers, the causative role of this kinase as
well as the signaling pathway(s) involved in their
survival and progression is unknown. This proposal
aims to more fully decipher the role of OPN in
cancer cell survival and metastasis by first elucidating
the roles of the integrin αVβ3 and the cell surface
receptor CD44 in the regulation of cancer cell
survival and progression through Akt. Prostate
cancer cells (PC3) have been chosen as a model
system due to there ability to express OPN and
metastasize to osseous structures, including the
mandible.
The down stream effects of the
engagement of OPN and its cell surface receptors will
focus on the cell signaling changes of integrin linked
kinase (ILK) and PI3-kinase, two important
regulators in the Akt cell survival mechanism. This
proposal aims to elucidate metastatic and survival
mechanisms by testing the over all hypothesis that the
6. DEPHOSPHORYLATION OF DNA LIGASE
I IN RESPONSE TO DNA DAMAGE
ENHANCES INTERACTION WITH THE
CELL-CYCLE CHECKPOINT CLAMP
LOADER hRad17-RFC
Wei Song1, David S. Levin, Johnson Varkey and Alan
E. Tomkinson
Morning; Oral Presentation; HSFII 241
DNA ligase I joins Okazaki fragments during DNA
replication and completes certain excision repair
pathways. The participation of DNA ligase I in these
transactions is directed by physical and functional
interactions with proliferating cell nuclear antigen, a
DNA sliding clamp, and, replications factor C, the
clamp loader. Here we show that DNA ligase I also
interacts with the hRad17 subunit of the hRad17-RFC
cell cycle checkpoint clamp loader, and with each of
the subunits of its DNA sliding clamp, the
heterotrimeric
hRad9-hRad1-hHus1
complex.
Notably, there are differences in the regions of DNA
ligase I involved in the interactions with replicative
and cell cycle checkpoint clamps and clamp loaders
29th Annual Graduate Research Conference
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synergistic activity of OPN on its cellular receptors
elicits the down stream cell signaling changes via
activating the PI3-kinase/Akt and ILK/Akt pathways
which play a crucial role in survival, migration, tumor
growth, and metastatic events of cancer cells.
into the mechanism of structural rearrangement
followed by this retroviral riboswitch.
8. REVEALING RETROVIRAL RNA
STRUCTURE AND DYNAMICS USING HIGH
RESOLUTION MASS SPECTROMETRY
Arie Hawkins; Eizadora Yu; Daniele Fabris
Morning; Oral Presentation; HSFII S600
9. GENETIC VARIANTS IN SLC4A3 AND
NPPC ARE ASSOCIATED WITH BLOOD
PRESSURE VARIATION IN THE OLD
ORDER AMISH
Ying Wang, Coleen Damcott, Patrick McArdle, Mark
Pohl, Christy Chang, Braxton Mitchell, Alan
Shuldiner, Nanette Steinle
Morning; Oral Presentation; HSFII S600
RNA molecules can fold in complex 3D structures
that, due to their size and flexibility, may represent a
challenge for many techniques. The problem is
exacerbated in retroviruses because regulatory
domains of the RNA genome can assume alternative
conformations that mediate different functions. In
HIV-1, the dimer initiation site of the packaging
signal can exist as a monomer, a kissing-loop (KL)
dimer, or as an extended-duplex (ED) in different
phases of the viral lifecycle. The conformation of this
domain can be identified in vitro by bifunctional
crosslinking and MS detection based on the
presence/absence of characteristic products. For
example, the A16/A17-G18 crosslink was
consistently observed in both dimeric forms, but was
conspicuously absent in a dimerization-deficient
mutant hairpin. Several crosslinks were unique to the
KL conformer due to their participation in base
pairing in the ED dimer. In MoMuLV, a pseudoknot
(PK) situated at the gag-pol junction is in equilibrium
with an upstream stemloop (SL) to facilitate an
essential ribosome decoding error. Using two
constructs that are able to form exclusively the PK or
the SL structure, chemical probes and crosslinkers
were employed to determine base accessibility and
long-distance spatial relationships. Also in this case,
the different constructs provided unique crosslinking
patterns that could serve as diagnostic of either
conformation. The spatial constraints were translated
into initial 3D models, which were refined and
minimized to obtain all-atom structures. Current
studies are aimed at investigating the effects of small
molecule ligands on the structures of the two
conformers, which will provide new critical insights
A 2.4-cM blood pressure (BP) quantitative trait locus
(QTL) has been identified on rat chromosome 9, a
region that is syntenic to human chromosome 2q36.
Two blood pressure candidate genes, solute carrier
family 4 member 3 (SLC4A3) and natriuretic peptide
precursor C (NPPC), have been mapped to this
region. SLC4A3 encodes the anion exchanger isoform
3, is expressed in heart, kidney, vasculature, and brain,
and performs an electroneutral exchange of chloride
and bicarbonate. NPPC encodes the C-type
natriuretic peptide, is expressed mainly in brain and
vasculature, possesses potent natriuretic, diuretic and
vasodilatory activities, and is implicated in body fluid
homeostasis and blood pressure control. We tested
the hypothesis that polymorphisms in SLC4A3
and/or NPPC are associated with blood pressure
variation by genotyping 4 common (MAF>0.1)
haplotype tagging SNPs (htSNPs) in a subset of
nondiabetic participants from the Amish Family
Diabetes Study (n=855). Of these, 2 htSNPs for
SLC4A3 (rs2305055 and rs684428) were selected
from the CEU HapMap database. Since no htSNPs in
the genomic region of NPPC were found in the
HapMap database, we sequenced this gene, identified
5 SNPs, and selected 2 (rs5262 and rs5268) as htSNPs
using the haploview tagger program. We found that
rs684428 in SLC4A3 was strongly association with
both DBP and SBP (p=0.0007 and 0.0046
respectively). Rs2305055 in SLC4A3 and rs5262 in
NPPC were also significantly associated with DBP
variation (p=0.03 and 0.0017, respectively). These
findings provide evidence that genetic polymorphisms
in SLC4A3 and NPPC are associated with BP
variation in the Old Order Amish. Further replication
29th Annual Graduate Research Conference
Friday, April 20, 2007
10
and functional studies will help us to understand their
role in blood pressure regulation.
HRPC models provides compelling evidence to
implicate them as mechanisms in progression and
offers opportunities for therapeutic targets.
10. SYNERGISTIC INHIBITION OF NOVEL
ANTI-ANDROGEN, VN/124-1, AND
EGFR/HER2 INHIBITOR, GEFITINIB IN
AN IN-VITRO AND IN-VIVO HORMONE
REFRACTORY PROSTATE CANCER
MODEL
Adam Schayowitz, Gauri Sabnis, Vincent Njar,
Angela Brodie
Morning; Oral Presentation; HSFII S600
11. ESTABLISHING SEX DIFFERENCES IN
THE DEVELOPING MALE BRAIN: A
NOVEL ROLE FOR ESTRADIOLENHANCED GLUTAMATE RELEASE
Jaclyn M. Schwarz and Margaret M. McCarthy
Morning; Oral Presentation; HSFII S600
Male and female brains exhibit fundamental
morphological differences thought to underlie the
differences in physiology and behavior between the
sexes. These sex differences are established during a
critical period of development, when testosterone
secreted from the developing testes is converted to
estradiol in neurons via the aromatase enzyme, to
permanently differentiate the male from the female
rodent brain. In the medial basal hypothalamus
(MBH) of newborn rats, males have twice the number
of dendritic spines on hypothalamic neurons as
females. Treatment of females with testosterone,
aromatized to estradiol, can increase the number of
dendritic spines on hypothalamic neurons to levels
seen in males at this time. We have determined that
estradiol’s increase in dendritic spines in this region
requires the activation of glutamate receptor
activation, yet the mechanism remains unknown. We
hypothesize that estradiol enhances release of
glutamate from presynaptic terminals. To test this
hypothesis, cultured hypothalamic neurons were
imaged with the fluorescent dye, FM4-64. FM4-64,
which loads and unloads from presynaptic terminals
upon depolarization, is a reliable method for
measuring neurotransmitter release from terminals.
We found that estradiol can significantly enhance the
rate of neurotransmitter release from hypothalamic
neurons compared to controls (H2=9.375; p =
0.0092). Neurons were then stained for the vesicular
glutamate transporter, vGLUT2, and were determined
to be glutamatergic. Based on these findings, our
current working model for sexual differentiation of
the MBH suggests that estradiol evokes glutamate
release from developing hypothalamic terminals,
Prostate cancer is the most commonly diagnosed
non-skin malignancy and the second leading cause of
cancer related deaths in US men. Androgen ablation
is often temporally successful in preventing or
delaying progression of disease, though approximately
70% of patients eventually progress to hormone
refractory prostate cancer (HRPC). In the current
studies, we have shown that HRPC cell lines (HPLNCaP) have a 4 fold increase in IGFR, a 2 fold
increase in HER activation, a 30% increase in pMAPK compared to hormone dependent LNCaP
cells. HRPC cell lines also show increased AR
expression. We have also identified a compensatory
signaling mechanism and cross-talk pathway between
AR and growth factor receptor HER2. Inhibition of
HER2 via gefitinib (Iressa) resulted in decreased
activity of p-Akt (50%), p-mTOR (60%) and PSA
(50%). Furthermore, AR protein expression more
than doubled within 24 hours of gefitinib treatment.
The novel anti-androgen, VN/124-1, increased
expression of IGFR (2.3 fold increase) p-HER (1.5
fold increase) and p-Akt (1.8 fold increase). In
accordance with protein expression, there was a 3
fold increase in AR activation demonstrated by the
luciferase activation assay in the presence of gefitinib.
Combination treatment with VN/124-1 + gefitinib
demonstrated significant synergistic inhibition of cell
proliferation in HRPC models. Additionally, in-vivo
data confirms in-vitro findings as VN/124-1 +
gefitinib inhibited tumor growth by more than 50%
compared to single agents. Increased activation of
multiple signaling pathways in HRPC models as well
as cross-talk between the AR and EGFR pathways in
29th Annual Graduate Research Conference
Friday, April 20, 2007
11
activating glutamate receptors on the post-synaptic
cell to increase dendritic spines in this region.
13. SVIP SERVES AS A BRAKE FOR gp78MEDIATED DEGRADATION OF
MISFOLDED ER PROTEINS
Petek Ballar1,4, Yuxian Shen1,Masami Nagahama2,
Mitsuo Tagaya3, Yongwang Wang1, Shengyun Fang1,
4
Afternoon; Oral Presentation; HSFII S600
12. MORPHOLOGICAL DYNAMICS OF
CENTRAL EXCITATORY SYNAPSES
JM Kerr and TA Blanpied
Morning; Oral Presentation; HSFII S600
Synapses are the contact points that allow
transmission of information from one neuron to the
next and changes in the structure and function of
synapses are thought to form the basis for learning
and memory. Efficient communication at synapses
requires
precise
alignment
of
presynaptic
neurotransmitter release machinery and the
postsynaptic density (PSD), a dense protein matrix
which anchors and regulates neurotransmitter
receptors. However, recent experiments have revealed
that the PSD is not a static structure. Surprisingly, it
changes shape on a minute-to-minute basis while
maintaining a stable molecular population. Our
hypothesis is that overall synapse morphology is
dynamically regulated to preserve the integrity of
synaptic transmission throughout PSD morphological
dynamics. Since PSDs at stable, resting synapses are
morphologically dynamic, the first question is
whether the presynaptic terminal undergoes
coordinated movement? Second, presynaptic
neurotransmitter quantification will be combined with
PSD imaging to explore how PSD morphological
dynamics may relate to synaptic transmission. Finally,
coordination of overall synapse morphology requires
a signal or link to connect the presynaptic and
postsynaptic
sides of the
synapse.
The
neurexin/neuroligin trans-synaptic connection is a
prime candidate given its important role in regulating
other forms of trans-synaptic coordination. In
summary, this investigation will provide a better
understanding of the function of individual excitatory
synapses. Furthermore, the results have implications
for understanding disease since the characteristics of
PSDs are altered in neurological, psychological, and
neurodegenerative disorders and genetic mutations in
neurexin and neuroligin are implicated in autism.
Aberrant degradation of misfolded proteins from the
endoplasmic reticulum (ER), a process known as the
ER-associated degradation (ERAD), contributes to
pathogenesis of many diseases such as cystic fibrosis,
neurodegenerative diseases, and diabetes. However,
the molecular mechanisms underlying the ERAD
process remain to be fully understood. We have
recently identified a novel VCP-interacting motif
(VIM) in gp78, a ubiquitin ligase functions in ERAD.
This motif recruits cytosolic VCP to the ER
membrane-an essential step in ERAD. A highly
conserved VIM is also present in the small VCPinteracting protein (SVIP), suggesting a functional
link between these two proteins. To test this
possibility, we demonstrated that SVIP is cofractionated with gp78, VCP, and Derlin1, all of
which are ERAD machineries. We further showed
that SVIP is anchored to the ER through
myristoylation and interacts with Derlin1 and VCP.
Silencing SVIP expression enhances the formation of
gp78-Derlin1-VCP complex, suggesting that SVIP
inhibits gp78 interaction with VCP and Derlin1.
Overexpressing SVIP inhibits the degradation of
CD3d and the Z variant of -1-antitrypsin, the known
substrates of gp78. Consistently, silencing SVIP
increases the degradation of these substrates. When
gp78 is overexpressed, silencing SVIP has no effects
on ERAD, suggesting that the overexpressed gp78
overcomes the inhibitory effects of SVIP. ER stress
inversely regulates the levels of SVIP and gp78
proteins. Changes in the ratio of gp78/SVIP protein
levels correlate well with the efficiency of ERAD.
Therefore, we have identified SVIP as the first
endogenous inhibitor of ERAD, which works
through competing with gp78 to bind VCP and
Derlin1.Regulation of SVIP expression may have
significant therapeutic value for cystic fibrosis.
29th Annual Graduate Research Conference
Friday, April 20, 2007
12
14. LUTEINIZING MACAQUE GRANULOSA
CELLS ARE REFRACTORY TO THE
MITOGENIC ACTIONS OF EGF-LIKE
LIGANDS
Muraly Puttabyatappa, Catherine A VandeVoort,
Charles L Chaffin
Afternoon; Oral Presentation; HSFII S600
15. POST-TRANSCRIPTIONAL
REGULATION OF RNase-L EXPRESSION
AND ACTIVITY IS MEDIATED BY
POSITIVE AND NEGATIVE ELEMENTS IN
ITS 3'UTR
Xiao-Ling Li1,2,3, Jesper B. Andersen1,2, Heather
Ezelle1,2, Gerald M. Wilson2,4,
Afternoon; Oral Presentation; HSFII S600
In primates, a mid-cycle surge of luteinizing hormone
(LH) initiates extrusion of a fertilizable oocyte and
remodeling of the follicle into a corpus luteum.
Luteinization of granulosa cells (GC) has been
associated with their abrupt exit from the cell cycle.
However, the LH surge induces mitogenic growth
factors, including members of the EGF family, and
GC express the EGF receptor (EGFR) before and
after an ovulatory stimulus. In this study we tested the
hypothesis that luteinizing GC are refractory to
growth stimulation by EGF-like ligands in vitro. GC
obtained from Rhesus monkeys undergoing superovulation were cultured in serum-free media with
hFSH or hCG for 24 hr, in the presence of vehicle,
EGF, betacellulin (BT), amphiregulin (AR), or
epiregulin (ER) ± the EGFR antagonist AG1478. In
the presence of FSH, 3H-thymidine incorporation
was increased by EGF, BT and AR while ER had no
effect. AG1478 completely blocked the effects of
EGF, BT, and AR. In contrast, none of the EGFR
ligands increased 3H-thymidine incorporation in the
presence of hCG. In order to determine the relative
time frame following hCG in which GC lose
responsiveness to EGFR ligands, cells were cultured
as above in the presence of 3mM BT for 3, 6, or 24
hr. Incorporation of 3H-thymidine did not change
over time with FSH for 24 hr, while addition of hCG
reduced 3H-thymidine incorporation compared to
their time-matched FSH controls. These data indicate
that primate GC respond to EGFR ligands prior to an
ovulatory stimulus, but lose their sensitivity to the
mitogenic effects of EGFs very rapidly after hCG.
The presence of EGFR in GC following hCG
suggests that cell cycle arrest is through down-stream
mechanisms while allowing for a possible antiapoptotic action of EGF-like ligands in primate GC.
Abstract RNase-L mediates critical cellular functions
including antiviral, pro-apoptotic, and tumor
suppressive activities; accordingly, its activity must be
tightly regulated. However, apart from the
requirement of 2’,5’-linked oligoadenylate for its
activation, little is known about the regulation of
RNase-L activity or expression. Here we examined
the post-transcriptional regulation of RNase-L
expression by a conserved, 1.75 kb 3’untranslated
region (3’UTR) in the RNase-L mRNA. The 3’UTR
mediated a potent inhibition of RNase-L, and
chimeric β-globin, expression that reflected a decrease
in mRNA stability. Eight candidate AU-rich elements
(AREs) were identified in the RNase-L 3’UTR. AREs
function in cis to regulate mRNA stability, and
deletion analysis identified positive and negative
regulatory regions associated with distinct AREs. In
particular, AREs 7 and 8 are located in the 3’terminus, and served a strong positive regulatory
function. HuR is an ARE binding protein that
stabilizes ARE-containing mRNAs, and a predicted
HuR binding site was identified in the region
comprising AREs 7 and 8. Co-transfection of HuR
and RNase-L enhanced RNase-L expression and
mRNA stability in a manner that was dependent on
this 3’-most region of the 3’UTR. HuR RNAimmunoprecipitation demonstrated that RNase-L
mRNA associates with HuR in intact cells. Activation
of endogenous HuR by cell stress, or during myoblast
differentiation, increased RNase-L expression,
suggesting that RNase-L mRNA is a physiologic
target for HuR. HuR- and 3’UTR-dependent
regulation of RNase-L modulated its antiviral and
antiproliferative
activities
demonstrating
the
functional significance of this regulation. These
findings identify a novel mechanism of RNase-L
regulation mediated via its 3’UTR.
29th Annual Graduate Research Conference
Friday, April 20, 2007
13
16. IDENTIFICATION AND INITIAL
CHARACTERIZATION OF THE MAJOR
ALTERNATIVE PROMOTER
CONTROLLING BCRP1 EXPRESSION IN
THE MOUSE SMALL INTESTINE
Karthika Natarajan, Takeo Nakanishi, Kenneth A.
Bauer and Douglas D. Ross
Afternoon; Oral Presentation; HSFII S600
17. ROLE OF PROSTAGLANDIN E2
RECEPTORS IN MEASURES OF
MASCULINIZATION OF THE RAT.
Christopher L Wright (1), Scott Burks (2), Margaret
M McCarthy (1,2).
Afternoon; Oral Presentation; HSFII S600
The potential for an organism to reproduce does not
only depend on the differentiation of the reproductive
organs but also organization of the bipotential
neuroarchitecture controlling sexual behavior during
development. Masculinization of sex behavior in the
rat is a gondal steroid driven process that occurs
during a sensitive perinatal window and involves
profound changes in the synaptic patterning of the
preoptic area (POA). We have previously reported
that estradiol, derived from aromatization of testicular
androgens, mediates masculinization of brain and
behavior by upregulating COX-2 and increasing
synthesis of Prostaglandin E2 (PGE2) in the POA.
PGE2 increases the density of dendritic spines on
POA neurons by two-fold and corroboratively the
animal will express robust male sexual behavior as an
adult (Amateau and McCarthy, 2002, 2004). Chief to
discovering the mechanism by which PGE2 elicits its
profound permanent effects is determining which of
the four receptors of PGE2, EP1-4, mediates the
signal
transduction
cascade
resulting
in
masculinization. To identify which EP receptors are
necessary for the masculinization of brain and
behavior,
we
have
used
antisense
oligodeoxynucleotides (AS) against EP receptors
followed by PGE2 administration after birth.
Animals treated with AS against EP2 & 4
receptors display marked decreases in measures of
male sexual behavior. To identify which receptors are
sufficient to mediate the effects of PGE2, we utilized
specific agonists for each of the EP receptors and
measured POA spinophilin protein levels because its
expression correlates with dendritic spine levels and
male sex behavior. Only EP4 agonist is sufficient to
mimic the effects of PGE2 on spinophilin levels and
inferentially dendritic spines.
BCRP expression in the human small intestine shows
huge inter-individual variability. It is reasonable to
postulate that such variation is the result of dietary
intake of substrates that may either repress or induce
expression of BCRP at the transcriptional level. To
investigate this in a murine model system, we seek to
characterize the transcriptional control mechanisms
that regulate the expression of Bcrp1/Abcg2 in the
small intestine.
Since our previous work found
evidence of multiple leader exons for human BCRP,
we first sought to identify all potential promoters for
Bcrp1/Abcg2. Alternative first exons for mouse
Bcrp1 mRNA were predicted using transcription start
site and promoter prediction programs and by
comparing the genomic 5’ upstream region of Bcrp1
with the murine EST database, using BLAST. 5’RACE PCR and qualitative RT-PCR were used to
confirm Bcrp1 mRNA isoforms utilized in the mouse
small intestine. Promoter activity associated with the
major Bcrp1 mRNA isoforms identified was
determined by the dual luciferase method.
We
identified four Bcrp1 mRNA isoforms located
approximately 72kb, 58kb, 15kb and 5kb upstream
from exon 2. These were designated E1U, E1A, E1B
and E1C respectively. E1B was the predominant
isoform identified in the mouse small intestine, along
with lesser amounts of E1A and E1C. E1U was not
detected. Deletion constructs of the region ~2kb 5’ to
E1A or E1B exhibited significant promoter activity.
Basal promoter activity for E1B was found to localize
to the -250 and +60bp region; cis elements in this
area are predicted to interact with transcription
factors including Hif-1α, SP1, CREB and NFkB.
Future studies are targeted at establishing whether
these factors regulate Bcrp1 transcription and
consequently Bcrp1 expression.
29th Annual Graduate Research Conference
Friday, April 20, 2007
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18. DELAYED RECOVERY OF SKELETAL
MUSCLE FUNCTION IN DYSFERLINDEFICIENT MICE FOLLOWING LARGESTRAIN LENGTHENING CONTRACTIONS
Joseph A. Roche, Richard M. Lovering, Robert J.
Bloch
Afternoon; Oral Presentation; HSFII S600
REQUIREMENTS AND SEQUENCE
SPECIFICITY.
Nuvjeevan S. Dosanjh and Sarah L. J Michel
Afternoon; Oral Presentation; HSFII S600
HPNikR, a prokaryotic nickel binding transcription
factor, is found in Helicobacter pylori where it
regulates multiple genes, including those involved in
acid adaptation and nickel ion homeostasis.
Particularly important is HPNikR's role in the
transcriptional regulation of the nickel-dependent
enzyme urease which is critical for the organism's
survival in the acidic environment of the gastric
epithelium. The target operator sequences of the
genes regulated by HPNikR do not contain any
identifiable palindromes, and the exact mechanism(s)
of the HPNikR-DNA recognition event is unknown.
HPNikR was expressed and purified as a soluble
protein containing mixed alpha/beta secondary
structure with evidence of a tertiary fold. A direct and
competitive fluorescence anisotropy (FA) assay to
probe both the metal ion requirements and sequence
specificity of HPNikR for PureA, the operator
sequence for the urease gene, was developed. FA
studies revealed that apo-HPNikR did not bind to
PureA while Ni(II)HPNikR bound PureA with
nanomolar affinity, but only in the presence of a
second metal ion [Mg, Ca, or Mn (II)]. Cu(II)HPNikR
also exhibited a requirement for a second metal ion to
accomplish PureA binding. Removal of a loosely
conserved
"putative"
palindrome
sequence in the PureA operator abrogated HPNikR
binding. Together, these results support a model of
HPNikR-PureA binding in which specific metal ions
must be coordinated to high- and low-affinity sites to
modulate binding. Current work is focused on the
creation of NikR mutants where specific Aspartic acid
residues (potential magnesium ligands) have been
modified. The mutant proteins will be assayed for
their DNA binding activities to probe the functional
relevance of those selected sites.
We have reported that recovery of contractile
function in skeletal muscle following a large-strain
lengthening contraction is independent of
myogenesis, but dependent on membrane repair
(Lovering et al., Arch. Phys. Med. Rehab., in press).
We hypothesize that dysferlin; a membrane repair
protein is required for normal recovery from injury.
Purpose: To test the hypothesis that recovery of
function
following
large-strain
lengthening
contractions is inhibited in mice lacking dysferlin.
Methods: Adult (12-14 wks), male, wild type (WT)
C57Bl/6J mice (N=32) and dysferlin-deficient A/J
mice (N=32) were studied. Fifteen Lengthening
contractions were used to induce an injury in the
hindlimb dorsiflexors. We measured dorsiflexor
torque before, immediately after, and at 3, 7, 14 and
21 days after injury. Fluorescein dextran (F-dx; 10
kDa) injected intraperitoneally before injury was used
to assess membrane damage. Results: On the day of
injury, torque was 67±13% and 63±8% of pre-injury
levels in WT and A/J respectively. Whereas A/J mice
recovered only partially 21 days after injury (73±1%),
WT recovered completely within 7 days (100±2%).
Membrane damage, measured as F-dx positive fibers,
increased from 2±0.5% before injury to 26±4%
immediately after injury in WT, and remained high
(29±2%) at the end of the 7-day recovery period. In
A/J, F-dx positive fibers increased from 12±4 % in
uninjured controls to 43±3% immediately after injury,
but decreased to 35±4%, 7 days later. Conclusion:
Dysferlin is necessary for normal recovery of
contractile function in skeletal muscle after injury by
large-strain lengthening contractions.
19. CHARACTERIZATION OF THE
HELICOBACTER PYLORI NIKR-P(UREA)
DNA INTERACTION: METAL ION
20. HISTONE DEACETYLASES ARE NOVEL
ISGYLATION TARGETS
Janette M Harro and Bret A Hassesl
Afternoon; Oral Presentation; HSFII 241
29th Annual Graduate Research Conference
Friday, April 20, 2007
15
ISG15 is an interferon (IFN)-regulated ubiquitin-like
protein that is implicated in the host immune
response. ISG15 is covalently linked to lysine
residues in target proteins (ISGylation) by enzymes
analogous to those that mediate ubiquitylation.
ISGylation is a dynamic process, with the ISG15
isopeptidase, UBP43, catalyzing the removal of
ISG15 from its substrates. In a screen for candidate
ISGylation substrates and UBP43 regulators, we
identified histone deacetylase 6 (HDAC6) as a novel
UBP43 interacting protein. Histone deacetylases
(HDACs) are a family of proteins that mediate
removal of acetyl groups from lysines in histone and
non-histone proteins. To determine if HDAC6 is an
ISGylation substrate, 293T cells were transfection
with UBE1L, UBC8, ISG15, and HDAC6 expression
plasmids. Immunoprecipitation of HDAC6 and
Western blot analysis with anti-ISG15 revealed
multiple immunoreactive bands suggesting HDAC6 is
modified at two or more lysines. Analysis of other
HDAC family members in the ISGylation
transfection system revealed multiple HDACs were
ISGylated. We focused upon HDAC6, as this
member interacts and maintains HSP90 in a
deacetylated state, which is specifically required for
HSP90 interaction and stabilization of client proteins.
HSP90 has been implicated in IFN action through
TBK-1 stabilization and IRF-3 activation, therefore
ISGylation of HDAC6 may modulate this activity.
Deletion analysis suggested the presence of two
ISGylation sites in HDAC6, and further mapping of
the ISGylated residues will permit the functional
analysis of this modification. HDACs modulate
diverse cellular functions, thus their regulation by
ISG15 may mediate, in part, the biological activities of
IFN.
proteins that cause ER stress, which either induces
cell death as in many neurodegenerative diseases and
diabetes, or promotes cell survival as in cancer. Cells
utilize Unfolded Protein Response (UPR) to alleviate
protein accumulation, which involves regulation of an
array of gene expressions. To further understand
UPR, we investigated the global changes of gene
expression in response to ER stress using microarray
analysis. Genes upregulated over two folds were
counted as positive hits. One of the hits encodes a
previously uncharacterized protein that we term as
SUPRESIN. We demonstrated that both mRNA and
protein of SUPRESIN are upregulated under ER
stress conditions. To determine its normal expression,
we found that SUPRESIN is highly expressed in
mouse stomach, small intestine, liver, pancreas, and
spleen, and lower or none in kidney, brain, heart and
skeletal muscle. Sequence analysis of SUPRESIN
reveals a putative signal peptide, suggesting that it
destines for the secretory pathway. Consistently,
SUPRESIN is localized within the microsome and
partially colocalized with ER and Golgi but not
mitochondria markers. In addition, SUPRESIN can
be detected in condition medium, especially when
overexpressed, indicating that it is also a secreted
protein. Silencing SUPRESIN expression in Hela cells
by siRNA oligos increases cell proliferation and
renders cells more susceptible to ER-stress-induced
cell death. Similar results were reproduced in U2OS
and Hela cells that stably express SUPRESIN
siRNAs. These results suggest that SUPRESIN may
play an important role in tumor cell survival and
growth under hypoxia condition that is known to
induce ER stress.
22. ENTEROAGGREGATIVE ESCHERICHIA
COLI DISRUPTS TIGHT JUNCTIONS OF
POLARIZED HUMAN INTESTINAL CELLS
Maura C. Strauman and James P. Nataro
Afternoon; Oral Presentation; HSFII 241
21.
SUPRESIN,
AN
ER
STRESS
UPREGULATED PROTEIN, INHIBITS CELL
GROWTH AND PROTECTS CELLS AGAINST
ER STRESS-INDUCED CELL DEATH
Andria Apostolou, Petek Ballar, and Shengyun Fang
Afternoon; Oral Presentation; HSFII 241
Enteroaggregative Escherichia coli (EAEC) is
responsible for inflammatory diarrhea worldwide.
Our prototype EAEC strain, 042, harbors a 100 kb
virulence plasmid called pAA2, which encodes the
AAF/II allele of the aggregative adherence fimbriae
Alterations in endoplasmic reticulum (ER)
homeostasis result in accumulation of misfolded
29th Annual Graduate Research Conference
Friday, April 20, 2007
16
(AAF). AAF/II is comprised of a major structural
subunit called AafA, and of a minor subunit called
AafB. We had previously observed that strain 042
induces IL-8 release in polarized human intestinal
cells. Many enteric pathogens that induce IL-8 release
also cause a decrease in Transepithelial Electrical
Resistance (TER), and a redistribution of tight
junction proteins. We therefore hypothesized that
TER would be reduced and that tight junctions (TJ)
would be disrupted in cells infected with 042. To test
this, we apically infected polarized T84 monolayers
grown on Transwell semi-permeable membrane
supports with 042 and several mutants, and used an
ELISA to measure basolateral IL-8 release; TER was
measured using an EVOM ohmmeter. An infection
of T84 cells with 042 caused elevated IL-8 release and
a drop in TER when compared with the uninfected
control. Cells infected with 042aafA (an afimbrial
mutant) released IL-8 at levels similar to uninfected
cells, and TER did not decrease. Interestingly, cells
infected with 042aafB (the minor subunit mutant)
released less IL-8 than 042 wild type (WT) parent, but
TER decreased to levels similar to those induced by
the WT. Immunofluorescence of cells infected with
042 indicated disorganization of TJ when compared
with healthy cells.
Our results supported our
hypothesis that 042 causes a TER decrease and TJ
disruption in T84 cells, and they suggest requirements
of AafA and AafB for a decrease in TER and WTlevel IL-8 signaling, respectively.
force, crushing strength, and content uniformity.
Results. While compression force was also studied,
NIRS yielded the most robust prediction models for
crushing strength and content uniformity using partial
least squares (PLS) regression with coefficients of
determination (r2) ranging from 0.971-0.993. For
crushing strength data of 5-15 kP, the standard error
of calibration (SEC), standard error of cross
validation (SECV), and standard error of prediction
(SEP) were 0.47, 0.51, and 0.61 kP, respectively.
Content uniformity data between 10.5-19.5 mg
showed SEC, SECV, and SEP values as 0.31, 0.43,
and 0.37 mg, respectively. Principal component
analysis (PCA) enabled the separation of 3 of the 5
doses as long as each was 4.5 mg apart; the greatest
variability was seen with the 10.5 mg dose. PCA also
showed that NIRS was sensitive enough to
differentiate between tablets prepared individually by
hand and those manufactured on a running rotary
tablet press. Conclusions. While robust calibration
models can be generated from NIRS data (R2 >
0.97) to accurately predict tablet crushing strength
and content uniformity; NIRS was superior in
predicting chemical over physical attributes. This
study demonstrates the potential of using NIRS data
for the rapid and non-destructive prediction of
crushing strength and content uniformity in
multiparticulate tableted systems.
24. CHARACTERIZATION OF DRUG
INTERACTION BETWEEN 3,4METHYLENEDIOXYMETHAMPHETAMIN
E (MDMA, ECSTASY) AND FLUOXETINE
(PROZAC®)
Vijay V. Upreti and Natalie D. Eddington
Afternoon; Oral Presentation; HSFII 241
23. NIR SPECTROSCOPY APPLICATIONS IN
THE DEVELOPMENT OF A COMPACTED
MULTIPARTICULATE SYSTEM FOR
MODIFIED RELEASE
S CANTOR, SW HOAG, LL AUGSBURGER
Afternoon; Oral Presentation; HSFII 241
Toxic drug interactions of MDMA may be a
contributing factor to the increasing number of
MDMA related deaths. Users often combine
fluoxetine with MDMA in order to avoid depression
after MDMA use and recently it has also been shown
that fluoxetine provides protection from MDMA
induced long term neurotoxicity in rats. However,
fluoxetine is a CYP2D6 and P-glycoprotein (P-gp)
inhibitor and may cause acute toxic drug interaction
Purpose. To study theophylline tablets developed
from the combination of modified release, extrusionspheronized
beads
containing
micronized
ethylcellulose (7 cP) and lipid-based placebo beads
using near-infrared spectroscopy (NIRS). Methods.
NIR spectra of tablets were recorded in reflectance
mode on a Model 6500 monochrometer and used to
develop multivariate regressions for compression
29th Annual Graduate Research Conference
Friday, April 20, 2007
17
with MDMA. Hence, the objectives of the present
study were to determine whether MDMA is a
substrate for P-gp and to investigate the
pharmacokinetic and pharmacodynamic (PD) drug
interaction between MDMA and fluoxetine. Brain
and plasma levels of MDMA were measured in P-gp
deficient [mdr1a(-/-)] and normal [mdr1a(+/+)] mice
following a single i.p. dose of MDMA. The effects of
pretreatment with fluoxetine on plasma and brain
levels of MDMA and its major active metabolite 3,4methylenedioxyamphetamine
(MDA)
were
investigated in SD rats after oral administration of
MDMA. A HPLC method with fluorescence
detection was used for quantitative determination of
MDMA and MDA in study matrices. As a PD
marker, plasma norepinephrine levels were measured
using an ELISA (data analysis under progress). No
significant differences in brain and plasma levels of
MDMA were seen in P-gp deficient and normal mice.
However, pretreatment of rats with fluoxetine
resulted in an increased MDMA (1.4-fold) and MDA
(1.5-fold) exposure of brain and plasma (p<0.001).
The t1/2 for MDMA increased from 2 to 5 h and for
MDA from 2 to 8 h upon fluoxetine pretreatment.
Results indicated that P-gp does not play a
physiologically significant role in determining the drug
interactions of MDMA. However, fluoxetine
coadministered with MDMA may lead to enhanced
risk of MDMA acute toxic effects.
replacement techniques to give 3D structures with
Rfree values of 0.277 and 0.281, respectively.
Pentamidine binds adjacent to Zn2+ in a small pocket
located at the S100B dimer interface and the electron
density is more readily defined for the inhibitor when
Zn2+ is present. The location of pentamidine in the
crystal structure is consistent with NMR data
including intermolecular NOE correlations, saturation
transfer difference (STD), and chemical shift
perturbations. The location of pentamidine nearby
the Zn2+ site on S100B represents a new small
molecule binding site, adjacent to the p53 binding
site, which could be important for developing
inhibitors of the S100B-p53 interaction.
26. A PROTEOMIC ANALYSIS REVEALS
THE DYSFUNCTION OF THE STAT3INHIBITOR GRIM-19 IN HUMAN RENAL
CELL CARCINOMA
Peng Sun, Shreeram C.Nallar, Iris Alchanati, Avi
Stein, Murray B. Resnick, Sekhar P. Reddy, Dhan
V.Kalvakolanu
Afternoon; Oral Presentation; HSFII 241
Interferon(IFN) and retinoids are potent tumor
growth inhibitors. We showed that the combination
of Interferon-β and retinoic acid synergistically
suppressed tumor growth by inducing apoptosis.
Using a genetic technique we have identified a novel
gene product GRIM-19(Gene associated with
Retinoid and Interferon induced Mortality-19), whose
inactivation promotes tumor growth. GRIM-19
inhibits the oncogenic transcription factor STAT3 for
promoting apoptosis. We have recently initiated a
study for defining the molecular changes associated
with human renal cell carcinoma (RCC) by comparing
the proteomes of normal and tumor kidneys from
patients using mass spectrometry. We have
discovered that expressionof GRIM-19 is lost or
severely depressed in a number of primary RCC and
in some urinogenital tumors. Using an RCC cell line,
we show that downregulation of GRIM-19 promotes
tumor growth via an augmentation of STAT3dependent gene expression. This is the the first study
that shows a tumor-suppressor like activity of GRIM19.
25. THE 3D STRUCTURES OF CA2+-S100B IN
ZN2+- AND PENTAMIDINE-BOUND
COMPLEXES AS DETERMINED BY X-RAY
CRYSTALLOGRAPHY
Thomas H. Charpentier, Paul T. Wilder, Kristen M.
Varney, Eric A. Toth and David J. Weber
Afternoon; Oral Presentation; HSFII 241
Structural studies are part of a rational drug design
program underway to inhibit the S100B-p53
interaction and restore p53 function in malignant
melanoma. Specifically, co-crystals of Zn2+-Ca2+S100B and pentamidine- Zn2+-Ca2+-S100B
diffracted to 2.35 and 2.2 Å in the space groups
C2221 and P41212, respectively. Both structures
were solved by X-ray crystallography using molecular
29th Annual Graduate Research Conference
Friday, April 20, 2007
18
Saranath Lawpoolsri, Irwin F.Chaves, Surapon
Yimsamran, Wuthichai Chaimoongkun, and Pratap
Singhasivanon
Morning; Oral Presentation; MSTF 156/158
27. A META-ANALYSIS OF RELATIONAHIPS
BETWEEN ORGANIZATIONAL CULTURE,
ORGANIZATIONAL CLIMATE, AND NURSE
WORK OUTCOMES
Yueh-Yen Fang
Morning; Oral Presentation; MSTF 156/158
The epidemiology of malaria is a product of complex
interactions between host, vector, and parasites that
are specific to each location. Between 1999 and 2005,
we studied a cohort of 2,680 residents living in 6
hamlets of Suanphung district, Thailand, an malariaendemic area along Thai-Myanmar border to
determine the pattern of malaria distribution, and to
examine possible risk factors for infection. Malaria
incidence (per 100 persons per year) gradually
decreased from 22 to 6 for P.falciparum, and from 13
to 2 for P.vivax, in 1999 and 2005, respectively.
Strong seasonal variation was observed with a peak of
transmission during the rainy season (April to July).
During the 7-year period, males experienced 1.6 times
as many episodes of falciparum malaria than females
and 1.4 times as many episodes of vivax malaria.
Malaria incidence rates of both P.falciparum and
P.vivax were higher among persons less than 20 yearold than older persons, consistent with development
of partial immunity with repeated infections. Malaria
incidence also differed across hamlets. Although the
incidence of malaria declined during the 7-year
period, the pattern of age-specific and gender-specific
malaria incidence did not changed. The current
findings demonstrate substantial variation in the
distribution of malaria in this area across space and
time. Further research is undergoing to determine
demographic
characteristics,
climate,
and
environmental factors that play an important role on
malaria transmission in this area. Identification of
high-risk area and potential risk factors of malaria will
allow control programs to be targeted for maximum
effect.
There is a constant debate on integrating or
differentiating the concepts of organizational culture
(OC) and organizational climate (OCL). The
inconsistent measure of OC and OCL and the mixed
use of these two terms in the empirical studies are
reflections of this problem. The results of empirical
studies, though inconsistent, show that OC and OCL
can influence nurses’ job satisfaction and turnover,
and therefore, indirectly create an impact on patients’
satisfaction. A meta-analysis on this subject would
benefit the clarification of the OC and OCL concepts
in healthcare settings and provide empirical support
for managerial decision-making. This study uses 35
computerized databases and footnote chasing
strategies to locate published and unpublished studies
that were conducted before February, 2007 and
evaluated relationships between OC, OCL, and two
nurse work outcomes (job satisfaction and turnover)
in hospital nursing samples from the U.S. A review of
6862 citations generates 16 unpublished doctoral
dissertations and 20 published studies to be included
in this study. Major analytical procedures performed
in this study are (1) estimation of the homogeneity of
studies and overall mean weighted effect sizes on the
paired relationships between OC, OCL, and nurse
work outcomes, (2) examining potential moderators
that account for variation in the magnitude of above
relationships, and (3) examining a path model that
presents the mediation effect of OCL on the
relationship between OC and two nurse work
outcomes. The bivariate relationships are evaluated by
meta-analysis. The results of meta-analysis are used in
the Structure Equation Modeling to evaluate the path
model.
29. INTIMATE PARTNER VIOLENCE IN
THE EVANGELICAL COMMUNITY
Juyoung Park
Morning; Oral Presentation; MSTF 156/158
28. THE EPIDEMIOLOGY OF MALARIA IN
AN ENDEMIC AREA ALONG THAIMYANMAR BORDER
There is a great deal of research on Intimate Partner
Violence (IPV), but few studies investigate the impact
29th Annual Graduate Research Conference
Friday, April 20, 2007
19
of religious attitudes and values on the problem, or
investigate faith-based prevention and interventions
strategies in religious communities. This qualitative
study with eight Evangelical pastors and eleven
clinicians aims to contribute to the relatively limited
empirical data in this area by examining the effect of
religious values and social attitudes on IPV in the
Evangelical community, and by investigating a range
of faith-based intervention that may be utilized. The
results focus on three main themes: a) gender roles vs.
psychopathology as main factors in IPV, b) religious
values and social attitudes as supports and barriers to
seeking help, and c) staying within tradition but using
a variety of clinical interventions.
Finally,
implications for practice with the Evangelical
community will be discussed.
PRACTICES CONCERNING TOBACCO AND
SMOKING CESSATION
Karen L. Parker
Morning; Oral Presentation; MSTF 156/158
Tobacco use, particularly cigarette smoking, causes
approximately 430,000 deaths annually in the United
States and is considered to be the number one
preventable cause of death (CDC, 2006; ACS, 2006;
Fiore, et al., 2000). Smoking cessation has immediate
and long-term health benefits (NCI, 2006). Specific
populations, such as individuals with low-incomes
and those with mental illness, are more likely to
smoke and thus be at increased risk for morbidity and
mortality (Fagan, et al., 2004; Williams &
Ziedonis, 2004); these populations are more likely to
come into contact with a social worker. Because the
social work profession is focused on providing
services to the most disadvantaged populations, issues
relating to tobacco use and cessation should be of
significant concern to the field. However, few social
workers are actively engaged in this issue (Kaplan
& Weiller, 1997; Valentich, 1994). Little is
known about the knowledge, attitudes and practices
of social workers concerning tobacco control and
smoking cessation. Understanding the barriers and
facilitators to adoption of anti-tobacco practices by
social workers can help the field become more active
in tobacco prevention and cessation efforts. An
integrated model of relevant theories will be
presented as a way to understand these barriers and
facilitators in the social work profession.
30. USING ADMINISTRATIVE DATA FOR
SOCIAL WORK RESEARCH: CHALLENGES,
BENEFITS, AND LESSONS LEARNED
FROM SECONDARY DATA ANALYSIS
R. Anna Hayward
Morning; Oral Presentation; MSTF 156/158
The use of large administrative datasets can present
both benefits and challenges to social work
researchers. An abundance of client and program
level data is readily available to researchers, usually at
minimal or no cost, and can provide ample data for
secondary analyses. Working with these large datasets
can be cumbersome, however, and present unique
challenges that researchers may not encounter when
planning and collecting their own data for analysis.
This presentation will discuss datasets that are
available and the challenges of using these data. This
presentation will also highlight an example of the
presenters own experience conducting secondary data
analysis with the Adoption and Foster Care
Administrative Reporting System (AFCARS) to
explore the experiences of children in the foster care
system who have experienced parental incarceration.
32. MENTAL HEALTH CONSEQUENCES OF
CHILD MALTREATMENT: HOW CERTAIN
ARE THESE CONSEQUENCES?
Sunday Fakunmoju
Morning; Oral Presentation; MSTF 156/158
Researches into mental health consequences of child
maltreatment have made significant advancements to
knowledge over the last two decades, and continue to
establish multiple dimensions of these consequences
on children and adults. In spite of this progress, there
remain considerable challenges to the validity of
research findings. These challenges evolve from the
31. INTEGRATING THEORIES TO
UNDERSTAND SOCIAL WORKERS'
KNOWLEDGE, ATTITUDES AND
29th Annual Graduate Research Conference
Friday, April 20, 2007
20
fact that: there is lack of consensus regarding the
definition of maltreatment; maltreatment could be
conceived from multiple perspectives; maltreatment is
measured
with
multiple
instruments;
and
maltreatment research is fraught with methodological
shortcomings.
These challenges is further
exacerbated by those who advocate for differentiation
in maltreatment conceptualization, especially in the
light of cultural differences about what constitutes
maltreatment, and those who believe that different
levels of maltreatments have different developmental
outcomes. Although maltreatment is a complex
multifarious phenomenon that has multiple
behavioral
internalizing
and
externalizing
consequences, there are dimensions in its nature and
type, frequency and severity, recurrence, and duration.
This analysis discusses the risk and protective factors
that escalate and mediate the cumulative effects of
maltreatment in childhood and adulthood, and
highlights the methodological options and policy
direction for conceptualizing maltreatment.
and adoption of preventive behaviors designed for
Chinese immigrants age 45 and above living in the
US. One hundred ten foreign-born Mandarinspeaking Asians were recruited to the study and 83 of
them were randomly assigned to either receive the
intervention (n=42) or to an attention control (n=41).
The results revealed that the participants who
received the SEOPE intervention had statistically
significant improvement at 2-week post intervention
with respect to: osteoporosis-related knowledge; SE
for exercise; and SE for osteoporosis medication
adherence. Although not statistically significant, the
treatment group had higher: OEs for exercise and
OEs for osteoporosis medication adherence, in
comparison to those who received an attention
control.
34. RELIABILITY AND VALIDITY OF THE
MSCEIT IN A MILITARY SAMPLE: A
MEASUREMENT PROPOSAL
Nikki R. Wooten
Afternoon; Oral Presentation; MSTF 156/158
33. SELF-EFFICACY ENHANCED
EDUCATION PROGRAM IN PREVENTING
OSTEOPOROSIS AMONG CHINESE
IMMIGRANTS
Bing-Bing Qi, RN, MSN
Afternoon; Oral Presentation; MSTF 156/158
Based upon the Four-Factor Model of Emotional
Intelligence, the Mayer-Salovey-Caruso Emotional
Intelligence Test (MSCEIT) is a 141-item, abilitybased scale that measures one’s abilities to perceive,
use, understand, and manage emotions.
The
MSCEIT’s
normative
sample
consists
of
approximately 5,000 male and female respondents age
17 and older; and has substantial reliability and
validity evidence. Yet, the normative sample is
predominantly American, female, and collegeeducated. In this proposal, methodologies to assess
reliability and validity in a military sample will be
presented. Strengths and limitations of the proposal
will be discussed as well as directions for future
research.
Studies have consistently reported that Chinese
particularly recent immigrants have a low bone
mineral density and to be at a great risk for
developing osteoporosis. There is considerable
evidence that the majority of Chinese of all ages have
inadequate information about their risks for
developing osteoporosis and are seldom involved in
preventive activities. Despite the benefits of
educational interventions designed for promoting
lifestyle changes, it is challenging to get Asians to
make these behavior changes. There is also growing
evidence of the effectiveness of self-efficacy (SE) in
changing behaviors among Asian minority
population. This study employed a randomized
controlled trial designed to evaluate the efficacy of SE
Theory based educational intervention (SEOPE)
aimed at increasing the knowledge of osteoporosis
35. STANDARDIZED CLIENTS IN SOCIAL
WORK EDUCATION: AN EMPIRICAL
EDUCATIONAL TOOL.
Shauna Acquavita
Afternoon; Oral Presentation; MSTF 156/158
29th Annual Graduate Research Conference
Friday, April 20, 2007
21
Standardized patients have been utilized to measure
medical students knowledge base and assessment of
skills for the past 40 years. This practice has not been
readily integrated in social work education (Badger;
MacNeil, 1998). Social work has changed the
terminology from standardized "patient” to “client”
to reflect the social work value of the person in the
environment (Miller, 2002). Providing a way to assess
clinical performance through objective data,
standardized clients are an empirical educational tool.
This presentation will discuss a literature review of
standardized client use in social work education from
1990 to 2006. Findings and recommendations for
future research in implementing standardized clients
in social work education will be addressed. Badger,
L.W.; MacNeil, G. (1998). Rationale for utilizing
standardized clients in the training and evaluation of
social work students. Journal of Teaching in Social
Work, 16, 203-218. Miller, M. (2002). Standardized
clients: an innovative approach to practice learning.
Social Work Education, 21, 663-670.
cross-cultural comparative research” (Rohner &
Kaleque, p. 3). This presentation explores the key
concepts associated with PARTheory. Similarities
and differences between PARTheory and other
mainstream theories are highlighted.
Strengths
related to the theory’s relevance to cross cultural
studies, as well as, studies of minority populations are
discussed. Finally, measures developed out of this
theory, particularly measures related to father
nurturance and associated child outcomes are
presented.
37. KEEP YOU EYES ON THE PRIZE:
PRESEVERANCE IN SOCIAL WORK
GRADUATE PROGRAMS FOR AFRICAN
AMERICAN WOMEN
Maya A. Gibbons, MSW
Afternoon; Oral Presentation; MSTF 156/158
This presentation discusses a qualitative research
project designed to examine the experiences of black
women in a predominantly white MSW program.
The literature on blacks in higher education is very
limited and, more specifically, the research on black
students in social work graduate programs is even
more scarce. This study is based on the grounded
theory model of qualitative research and employed
several methods of data collection including personal
interviews and a participant observation. Two black
female MSW students were interviewed with a focus
on their experiences of exclusion, support and racism
in the MSW program at a large east-coast social work
graduate program. Additional themes were explored
based on information that emerged during the
interview. A research methods class was also
observed to provide further congruence and insight
into the interactions of black students in the
classroom. Findings from this study suggest that
perseverance is an overarching theme that connects
the experiences of both informants and is what
propels them to remain in the program and reach
their goals despite any obstacles. A number of other
key themes were also discovered but were all related
to the larger concept of perseverance. Implications
for social work include that in order to reverse the
downward enrollment trend for blacks in MSW
36. APPLYING THEORY TO FATHERHOOD
RESEARCH: RECONSIDERING THE
FRAMEWORKS GUIDING OUR INQUIRIES
Otima Doyle
Afternoon; Oral Presentation; MSTF 156/158
As with many areas of study, there is no grand
unifying theory for fatherhood, motherhood, or
parenting to guide research (Roggman, Fitzgerald,
Bradley, & Raikes, 2002). There are, however, a
number of theories that are potentially helpful in
explaining the influence that fathers, in particular,
have on their children. In spite of this fact, much
research in this area has been initiated and executed
outside of the realm of theory (Roggman et al., 2002).
“Parental Acceptance Rejection Theory (PARTheory)
is an evidence based theory of socialization and life
span development that attempts to predict and
explain major causes, consequences, and other
correlates of parental acceptance and rejection within
the United Sates and worldwide” (Rohner & Kaleque,
2005, p. 4). PARTheory emerged in the 1960’s out of
both the United States’ psychological traditions and
the “…anthropological and psychological program of
29th Annual Graduate Research Conference
Friday, April 20, 2007
22
programs schools need to examine their
environments and make sure they are inclusive and
supportive for all minorities.
human MYH.
The fragment, referred to as
MYHδC5, contains residues 65-350 of the 535residue protein. We have obtained diffraction of the
crystals to 2.2 Å resolution and we will complete
single anomalous dispersion (SAD) and multiple
anomalous dispersion (MAD) experiments to obtain
the phases of our data. MutS-α (a protein required
for mismatch repair), Hus1 (of the 9-1-1 complex),
and APE1 (an endonuclease involved in BER) all
bind to MYH within that domain. In addition to
structural studies, we will compare the biochemical
activities of MYHδC5 with the full-length protein
using DNA-binding anisotropy experiments and
protein-protein interaction studies via isothermal
titration calorimetry.
38. FEMALE OFFENDERS IN THE U.S.
PRISON POPULATION
Vickie Souther
Afternoon; Oral Presentation; MSTF 156/158
Today in the United States, one out of every four
juveniles arrested is female and the population of
women in prison continues to soar, tripling in the
past decade. This presentation attempts to explain the
phenomenon of rising female crimes rates from a
feminist perspective by exploring the following:
•Female pathways to offending •The continuum of
criminal behavior for women •Criminal justice system
response to the female offender
102. ZINC INDUCED FOS GENE
EXPRESSION IN PROSTATE CANCER
CELLS
Shu-fei Lin, Hua Wei, and Pei Feng
Afternoon; Poster Presentation; MSTF Atrium
101. STRUCTURAL AND BIOPHYSICAL
CHARACTERIZATION OF A DNA REPAIR
ENZYME, MUT Y HOMOLOG
Paz J. Luncsford, Eric A. Toth
Afternoon; Poster Presentation; MSTF Atrium
The fos gene encodes transcriptional factor Fos,
which has been shown to be associated with cell
apoptosis in photoreceptor cells and hepatocytes.
Fos-related molecular events in prostate malignancy
have not yet been elucidated. It is known that normal
prostate contains the highest zinc level in the body,
and the loss of zinc status is a most consistent and
persistent characteristic of prostate malignancy. We
have demonstrated that zinc exposure induces
apoptosis in human prostate cancer cells (PC-3), but
not in normal prostate cells (HPR-1). Our recent
microarray assay revealed a zinc-induction of fos
mRNA expression in PC-3, but not in HPR-1. The
zinc effect on Fos expression was conducted with a
time course study (1, 3, 6 and 24 hrs) of the zinc
(1,000ng/mL) regulation in 4 human prostate cell
lines: normal (HPR-1), benign hyperplasia (BPH),
malignant LNCaP and PC-3. The fos transcript levels
were determined by RT-PCR and the Fos proteins
were identified by Western Blot analysis. A significant
zinc induction was detected in LNCaP and in PC-3
with up to 3-fold as early as 1 hr after zinc treatment,
while no significant response observed in HPR-1 and
in BPH. Accordance with the zinc-induced fos
7,8-dihydro-8-oxoguanine (GO) is one of the most
common DNA lesions formed and occurs when
guanines are subjected to both cellular and exogenous
sources of oxidative damage. GO contributes to
genomic instability in that it can mispair with adenines
during DNA replication, resulting in G:C to T:A
transversions. Escherichia coli MutY and eukaryotic
MutY homolog (MYH) are DNA glycosylases,
utilized in the base excision repair (BER) pathway,
that are specifically responsible for removing adenines
that have been incorrectly incorporated opposite GO.
Mutations in the gene encoding for human MYH
have been implicated in the development of colorectal
cancers and therefore studying the interaction of
MYH with signaling pathways that mediate apoptosis
or cellular proliferation is an important area of study.
Gilboa et al. published the crystal structure of the
catalytic domain of E. coli MutY in 2002. However,
E. coli MutY and human MYH only share a low
sequence homology. Our lab has been successful in
obtaining crystals of a fragment of recombinant
29th Annual Graduate Research Conference
Friday, April 20, 2007
23
mRNA levels, zinc-elevated Fos proteins were also
observed in malignant LNCaP and PC-3 with up to 5fold while weaker induction detected in normal cells.
In addition, the greatest endogenous fos mRNA and
Fos protein levels were detected in both normal
HPR-1 and BPH, with ~ 2.2 to 4.4 times greater than
in malignant LNCaP and PC-3. Fos expression and its
regulation by zinc are prostate cell type specific: Fos
which is constitutively activated in normal and benign
prostate cells is considerable to be used as a
biomarker for the progression of oncogenetic events
in prostate cancer.
1,090 hours for individual patients in cycle one.
Plasma α1-Acid Glycoprotein (AAG) levels were
measured on the first day of cycles one and two,
which ranged from 121 to 175µg/dL. Based on the
information obtained in this analysis, a population
pharmacokinetic analysis of this study will be
conducted in order to determine what covariates are
considered important in determining plasma
concentrations in various patient populations. One
major covariate to be evaluated will be AAG because
of its impact in this analysis.
104. IMMUNOGLOBULINS TO SURFACEASSOCIATED BIOFILM IMMUNOGENS
PROVIDE A NOVEL MEANS OF
VISUALIZATION OF METHICILLINRESISTANT STAPHYLOCOCCUS AUREUS
BIOFILMS
Rebecca A. Brady, Jeff G. Leid, Jennifer Kofonow, J.
William Costerton, and Mark E. Shirtliff
Afternoon; Poster Presentation; MSTF Atrium
103. A NONCOMPARTMENTAL
PHARMACOKINETIC ANALYSIS OF A
PHASE I STUDY OF UCN-01 IN
COMBINATION WITH CARBOPLATIN IN
ADVANCE SOLID TUMORS
Charlene Baksh, Pharm.D, Kenneth S. Bauer, Ph.D
Morning; Poster Presentation; MSTF Atrium
UCN-01 (7-Hydroxystaurosporine) is a protein kinase
inhibitor that has been shown to have 3 effects in
tumor cells: (1) cell-cycle arrest, (2) induction of
apoptosis, and (3) sensitization to DNA-damaging
agents (Fuse E., 2005). In a recent study conducted at
the University of Maryland Hospital Greenbaum
Cancer Center, selected patients participated a
combination study of UCN-01 and carboplatin. This
was a phase 1 trial where UCN-01 was given as a 3hour infusion to 21 patients. Blood collection
occurred immediately prior to and at 0.5, 1, 2, and 3
hours after the start of infusion. Following the
infusion, blood was drawn at 2, 4, 8, 24, 48 hours, and
on days 7 and 21 (pre-treatment for the following
cycle served as the day 21 sample). Plasma
concentrations were determined using a previously
published reverse-phase HPLC assay method (Bauer
KS, 2000). Samples were available from 21 of the 23
patients who were originally enrolled in the study.
Noncompartmental plasma sample analysis was
performed using WinNonlin® on the data obtained
from this study. The maximum plasma concentrations
achieved were in the range of 20 to 40µM (9.65 to
19.3µg/mL). The terminal elimination half-life was
variable ranging from around 113 hours to roughly
Though usually a nosocomial pathogen, methicillinresistant Staphylococcus aureus (MRSA) is
increasingly emerging in the community. One way in
which MRSA is able to persist in the host is through
growth as a biofilm. Biofilm-associated MRSA
infections are more resistant to antimicrobial killing
than planktonic bacteria and avoid clearance by the
immune response. In previous work we identified 22
antigens from the MRSA cell wall that are
immunogenic in vivo and upregulated during biofilm
growth. We hypothesized that these immunogens
could be used to create antibody-based imaging and
diagnostic tools. Recombinant forms of biofilm
upregulated proteins (lipase, SA0486, SA0688,
glucosaminidase, and conserved hypothetical protein
SA0037) were expressed in Escherichia coli.
Immunoblotting the recombinant proteins with sera
from our model of biofilm infection confirmed that
these antigens (with the exception of SA0486) were
immunogenic during MRSA osteomyelitis and that
the conformations of the recombinant proteins
resembled those found in the biofilm. Rabbits were
vaccinated with the recombinant proteins to elicit an
antibody response. For every antigen tested, purified
29th Annual Graduate Research Conference
Friday, April 20, 2007
24
IgG from these rabbits recognized the cognate
proteins from the biofilm via immunoblotting. When
applied to intact MRSA biofilms grown in flow cells
and visualized via immunofluorescence, every IgG
except anti-lipase was able to specifically bind to the
biofilm. This illustrates that proteins that are
immunogenic, cell wall-associated, and upregulated
during biofilm growth are promising for in vitro
visualization of biofilm growth and architecture.
Future work involves utilizing radiolabeled conjugates
of these IgGs in biofilm-infected rabbits for
visualization of MRSA biofilms in vivo.
mRNA levels at 2 or 4 h in these cells. HIF-1α was
readily detectable, however, in cells 2 and 4 h after of
treatment with CoCl2 alone. When cells were treated
with both CoCl2 and E2, however, there was a
synergistic increase in VEGF mRNA levels by 4 h,
which is similar to the magnitude of induction in vivo.
These results support our hypothesis that HIF-1α
plays an essential role in E2 induction of VEGF
expression. This work supported by NICHD U54
Cooperative Centers Program HD36207.
106. MOLECULAR DYNAMICS STUDIES ON
THE CLOSED TO OPEN TRANSITION OF
THE SHP-2 N-SH2-DOMAIN
PHOSPHOTYROSINE-PEPTIDE BINDING
CLEFT
Olgun Guvench, Cheng-Kui Qu, and Alexander D.
MacKerell, Jr.
Afternoon; Poster Presentation; MSTF Atrium
105. THE ACTIONS OF COBALT CHLORIDE
ON HYPOXIA INDUCIBLE FACTOR 1α AND
VASCULAR ENDOTHELIAL GROWTH
FACTOR IN ENDOMETRIAL CANCER
CELLS IN VITRO.
Kristin Happ Molitoris; Robert D. Koos
Afternoon; Poster Presentation; MSTF Atrium
The N-terminal SH2 domain (N-SH2) of the nonreceptor tyrosine phosphatase SHP-2 is involved in
localization of SHP-2 by recognition of
phosphotyrosine (pY) peptides as well as selfinhibition of SHP-2 phosphatase activity through the
formation of a protein-protein interface with the
phosphatase domain. Mutations that disrupt this
interface can increase both SHP-2 phosphatase
activity and pY-peptide binding affinity, and are
associated with pediatric leukemias and the congenital
condition Noonan syndrome. We have applied
explicit-solvent molecular dynamics simulations to
study the closed to open transition of the N-SH2 pYpeptide binding cleft so as to better characterize the
molecular process involved in N-SH2 pY-dependent
binding. The simulations show that changes in the
backbone conformation of a single residue, Tyr66,
can control this transition by inducing loop motion.
The existence of stable conformations in the lefthanded helical and the extended regions of Tyr66
phi/psi space prevent rapid interconversion of the
backbone and create a conformational switch.
Additionally, in the open conformation, sidechainsidechain interactions serve to pin the Tyr66 sidechain
to the surface of the protein and away from the
binding cleft entrance, unlike in the closed
Estradiol (E2) rapidly and strongly induces vascular
endothelial growth factor (VEGF) transcription in the
uterine endometrium.
Previous work in our
laboratory [Kazi A et al. 2005] has shown that the
transcription factor hypoxia inducible factor 1α (HIF1α) mediates E2-induced VEGF expression in the
endometrium. In contrast to this, E2 induces little or
no VEGF expression in various cell lines in vitro.
One major difference between in vitro and in vivo
studies is that cells are exposed to a high, nonphysiological oxygen concentration (20%) in culture,
leading to HIF-1α degradation in vitro, which could
explain why E2 only weakly induces VEGF in culture.
We hypothesized that maintaining adequate levels of
HIF-1α in cells would restore the ability of E2 to
strongly induce VEGF gene transcription. To test
this, we treated human endometrial cancer cells
(ECC-1) with E2 (10 nM) in the absence or presence
of cobalt chloride (CoCl2; 100 µM), which prevents
oxygen-induced HIF-1α degradation, for 0, 2, or 4 h.
HIF-1α protein levels were determined using Western
blots and VEGF mRNA was measured using
quantitative real-time RT-PCR.
HIF-1α was
undetectable in untreated ECC-1 cells, and as
expected, E2 treatment did not increase VEGF
29th Annual Graduate Research Conference
Friday, April 20, 2007
25
conformation where this sidechain partially occludes
the cleft. The conformational properties of the Tyr66
backbone and sidechain suggest a mechanism for pYpeptide binding, and the structurally well-defined
binding cleft conformations resulting from the
switch-like nature of the transition imply the
possibility of using structure-based methods to
develop inhibitors of N-SH2 pY-peptide binding.
108. CONTINUED RESEARCH ON DONORACCEPTOR FLUOROPHORE PAIRS FOR
USE AS CALIBRATION STANDARDS
Bryan McCranor, Dr. Richard Thompson
Afternoon; Poster Presentation; MSTF Atrium
Fluorescence emission can give useful data on
particular molecules, which can be applied and
incorporated into many fields of study. As this
technology makes its way into more laboratories the
demand for more precise calibration standards
increases. Currently, simple standards, such as
Rayleigh scatterers, are used but they do not account
for the “color effect” or other artifacts. Although
using W/R928 PMT’s can correct the “color effect”,
using a system of standardized fluorophore dyes will
not only correct this but other artifacts as well, and
ultimately lead to more accurate measurements. By
using a set of standards that have a range of differing
lifetimes, a calibration curve for the instrumentation
can be obtained. For our study we chose to use the
standard fluorophore 3,3-Diethylthiadicarbocyanine
Iodide (DTDCI), which has an emission lifetime of
~1.7 ns, and paired it with the acceptor fluorophore
Janus Green B. Increasing the concentration of Janus
Green B causes a decrease in the lifetime of DTDCI
emission, which can be measured on a frequencydependent phase and modulation curve. The fast
emission lifetime of DTDCI allows us to neglect the
diffusion factor of the two fluorophores in solution,
and apply a simpler fit to the phase and modulation
curve. Early results indicated that the DTDCI-Janus
Green B pair would make for a good standard, but
problems of reproducibility quickly arose, especially in
the short fiber set-up. While the rationale behind the
fluorophore standards remain sound, a different
fluorophore pair that behaves better in a short fiber
set-up needs to be chosen.
107. OXIDATION STUDIES OF TTP nUP475,
A NON-CLASSICAL ZINE FINGER
PROTEIN INVOLVED IN INFLAMMATORY
RESPONSE
Seung Jae Lee, Sarah L. J. Michel
Afternoon; Poster Presentation; MSTF Atrium
The eukaryotic protein tristetraprolin (TTP, also
know as NUP475 and TIS 11) is a non classical zinc
finger protein involved in regulating inflammatory
response. TTP binds to AU-rich sequence elements
located at the 3’-untranslated region of cytokine
mRNAs forming a complex that is degraded by the
exosome. We have shown that although a metal is
required for RNA binding, the identity of the metal
ion is flexible and both Fe(II) and Fe(III) substituted
TTP bind RNA with approximately the same affinity
as Zn(II) substituted TTP (1).
We are currently
investigating how the nature of the metal ion bound
to TTP affects its susceptibility to oxidation. TTP is
found in the cytoplasm during periods of
inflammation under which both iron levels and
reactive oxygen species are abundant. As such, iron
bound TTP may undergo redox reactions which
could damage the RNA. As a first step, we have
developed an assay to assess the oxidation levels of
apo, Zn and Fe(II) bound to the first zinc finger
domain of TTP (TTP-D1). These studies may
contribute to our understanding the of the redox
properties of zinc finger proteins such as TTP. (1)
diTargiani RC, Lee SJ, Wassink S, Michel SLJ;
“Functional characterization of iron-substituted
tristetraprolin-2D (TTP-2D, NUP475-2D): RNA
binding affinity and selectivity.” Biochemistry. 2006,
Nov 14;45(45):13641-9.
109. THE INFLUENCE OF TILT ANGLES
ON THE EFFICIENCIES OF JET
NEBULIZERS
Feiyan Jin and Richard N. Dalby
Afternoon; Poster Presentation; MSTF Atrium
29th Annual Graduate Research Conference
Friday, April 20, 2007
26
Purpose: To gravimetrically assess the influence of
nebulizer orientation on emptying efficiency of four
commercially available jet nebulizers. Methods: Salter
Labs One No. 8900, Misty-Neb, Acorn II and Pari
LC Jet nebulizers were operated using a
DeVilbissPulmo-Aide 5650D compressor to atomize
3mL of water (used as surrogate drug solution). The
jet nebulizers were run until sputtering, vertically, and
tilted at 30, 45 and 60 degrees to the vertical.
Nebulization efficiency was defined as the percentage
of the original mass of water emitted from the
mouthpiece (n=6). Results: At 0 (vertical), 30, 45 and
60 degrees, the Salter Labs nebulizer emptied
46±2.7% (mean±s.d.), 52±1.8%, 50±1.2% and
47±2.5% respectively. Compared to vertical
operation, this represents an increase of
14%(p<0.05), 9.7%(p<0.05) and 1.5%(p>0.05)
at 30, 45 and 60 degrees, respectively. At 60 degrees,
the Misty-Neb, Acorn II and Pari LC nebulizers
yielded nebulization efficiencies of 62±0.3%,
61±1.3% and 49±1.6%, respectively. The Acorn II
showed the highest increase of 30%(p<0.05); the
Pari LC exhibited a significant decrease of
17%(p<0.05), and the Misty-Neb showed a
marginal increase of 3.7%(p<0.05) compared to
emptying in the vertical orientation. Conclusions: The
results of even this most basic metric of nebulizer
efficiency are orientation dependent and specific
nebulizers exhibit output changes that may increase,
decrease, or be essentially unchanged when the
orientation deviates from the vertical position. For
this reason, the dose to patient delivered by nebulizers
can be expected to be orientation dependent, and not
reflected by in vitro tests conducted in a single
orientation.
research. Many technical difficulties, including
efficient tissue-specific delivery, integration site
specificity and general toxicity, are being addressed.
Little is known, however, about the genetic and
phenotypic stability that accompanies a successful
gene-specific targeting event in a cancer cell. This
question was addressed following the creation of a
colon cancer cell line in which a mutated hMLH1
gene was corrected via targeted homologous
recombination. This correction resulted in the
expression of wild-type hMLH1 protein, restoration
of the hPMS2 protein and mismatch repair (MMR)
proficiency. One of two hMLH1-corrected clones,
however, was found to retain defects in MMR
activity. These cells continued to express the
corrected hMLH1 protein, but had lost expression of
another MMR protein, hMSH6. DNA sequence
analysis of the hMSH6 gene revealed biallelic
expansions of a cytosine repeat region in exon 5 that
result in frameshifts leading to premature stop
codons. These findings suggest that, similar to
acquired drug resistance, the presence of genetically
heterogeneous cancer cell populations or acquisition
of compensatory mutations can result in resistance to
gene replacement therapy.
111. CHARMM ALL-ATOM ADDITIVE
FORCE FIELD FOR CARBOHYDRATES
Ganesh Kamath
Afternoon; Poster Presentation; MSTF Atrium
Carbohydrates play a central role in molecular biology
where they serve as a storehouse for energy, as
structural elements, and as components of molecularrecognition
networks.
Molecular
mechanics
simulations provide a means to investigate the
biological functions of carbohydrates at an atomic
level of detail. Toward this end, the present work
details recent efforts at developing an all-atom
additive
CHARMM
molecular
mechanics
carbohydrate force field. The results include
parametrization
via
the
reproduction
of
conformational, spectroscopic, and thermodynamic
aspects of small-molecule compounds that
correspond
to
fragments
of
pyranose
monosaccharides. Additionally, over 1600 pyranose
110. PERSISTENT MISMATCH REPAIR
DEFICIENCY FOLLOWING TARGETED
CORRECTION OF HUMAN MLH1
MB Weiss, MI Vitolo, K Baerenfaller, G Marra, BH
Park, KE Bachman
Afternoon; Poster Presentation; MSTF Atrium
The use of gene therapy to correct mutated or lost
gene function for the treatment of human cancers has
been an active, yet problematic area of biomedical
29th Annual Graduate Research Conference
Friday, April 20, 2007
27
monosaccharide conformational energies at the
quantum
mechanical
MP2/cc-pVTZ//MP2/631G(d) level are used as target data for the
parametrization of intramolecular conformational
energetics. The resultant parameters are tested in
crystalline and solvated monosaccharide condensed
phase simulations. The force field is also extended to
enable modeling of di- and polysaccharides. The
nonbonded parameters of the glycosidic oxygen are
empirically fitted to reproduce water dimer
interactions of polysaccharides with varying
conformers and glycosidic linkages. Dihedral
parameters are fitted to reproduce MP2/ccpVTZ//MP2/6-31g(d) adiabatic potential phi/psi
energy scans for different glycosidic linkages, and the
resultant force field parameters are applied to
investigate the condensed phase properties of
polysaccharides. The parametrization protocol is
consistent with that employed for the existing
CHARMM protein, nucleic acid, and lipid force
fields.
stacking interactions are significantly lower for the
higher concentration systems compared to either 0, 1
or 2M urea solutions. Solvent accessibility and
solvation number evaluations indicate that higher
concentrations of urea lead to dehydration of the
backbone and the bases of the RNA are exposed via
base opening. This is also reflected in the decreasing
number of intact hydrogen bonds within the base
pairs of the RNA in high urea concentrations.
Interestingly, by all the measures RNA in 1 and 2M
urea solutions is more stable than in the aqueous
solution with less flexibility.
113. EFFECT OF CORTICAL LAYER ON
MESOCORTICAL ACTIVATION OF
PYRAMIDAL NEURONS IN THE
PREFRONTAL CORTEX
Kathy Toreson and Patricio O'Donnell
Afternoon; Poster Presentation; MSTF Atrium
Pyramidal projection neurons of the prefrontal cortex
(PFC) receive dopaminergic input from the ventral
tegmental area (VTA). This mesocortical projection,
which is important for information processing in the
PFC, does not have a uniform density of distribution
across the layers of the cortex. To investigate
whether the effect of mesocortical projection
activation on pyramidal neurons of the PFC is
affected by cortical layer, we performed in vivo
juxtacellular recordings of pyramidal neurons in
medial PFC of chloral hydrate anesthetized rats.
Neurobiotin staining confirmed the morphology of
recorded cells as pyramidal neurons and as well as
identified the cortical layer in which these cells were
located within the prelimbic and infralimbic cortices.
VTA activation by electrical stimulation (20 Hz five
pulse train) produced both simple and complex
response patterns in pyramidal neurons, which could
contain both excitatory and inhibitory components.
Responses with multiple components suggest that the
mesocortical activation may be influencing the
pyramidal neurons directly as well as indirectly via the
local circuit interneurons. These results suggest that
activation of the mesocortical pathway produces
different and complex effects on PFC activity.
112. DENATURATION OF P5GA RNA BY
UREA: A MOLECULAR DYNAMICS STUDY
ON THE ATOMIC DETAILS OF THE
INTERACTIONS OF UREA WITH RNA
U. Deva Priyakumar
Afternoon; Poster Presentation; MSTF Atrium
Urea titrations are helpful in deriving the
unfolding/folding free energies and in obtaining
information about the pathway of unfolding for
proteins and nucleic acids. While several studies on
urea denaturation of RNA have been reported, the
atomic details of the mechanism of action of urea in
denaturing RNA are not completely understood. 20
ns molecular dynamics simulations have been
performed
on
P5GA
RNA
hairpin
(GGCGAAGUCGAAAGAUGGCGCC) in aqueous
solution and in various concentrations of urea (1, 2, 4,
6 and 8M) to elucidate the structural and energetic
basis of the interaction of urea with RNA. While the
overall RMS deviations of the RNA do not reflect a
definitive trend, the deviations of the canonical part
of the RNA increases with the increase in the
concentration of urea. The base pair interactions and
29th Annual Graduate Research Conference
Friday, April 20, 2007
28
114. PULSED ELECTROCHEMICAL
DETECTION FOLLOWING HIGH
PERFORMANCE LIQUID
CHROMATOGRAPHY OF
AMINOGLYCOSIDIC ANTIBIOTICS
Jennifer Fedorowski, Ronita Marple, William R.
LaCourse Ph.D
Afternoon; Poster Presentation; MSTF Atrium
115. ZINC REGULATION OF
METALLOTHIONEINS (MT1/2, 3)
EXPRESSION IN HUMAN PROSTATE
NORMAL AND MALIGNANT CELLS
Hua Wei, Shufei Lin and Pei Feng
Afternoon; Poster Presentation; MSTF Atrium
Zinc is an essential element involved in many cell
functions. Normal prostate contains the highest zinc
level, but a dramatic decrease of cellular zinc was
found in malignant prostate cells. Metallothioneins
(MTs) are a family of low molecular proteins, which
have 4 isoforms. MTs are closely related to zinc
homeostasis. Up to date, in prostate the zinc
regulation of MT1/2 and MT3 expression in relation
to zinc accumulation and tumorigenesis remains
unclear. This study focused on the zinc regulation of
MT1/2 and MT/3 expression in relation to cellular
zinc accumulation. A time-course study of zinc
regulation of MT1/2 and MT3 gene transcriptions
and the protein levels in 3 human prostate cell lines:
HPR-1, BPH and PC-3, was performed. The results
of Western blot analysis showed that zinc significantly
induced MT1/2 in BPH and PC-3 as time dependent,
but not in HPR-1. About 2 fold increase of MT1/2
compared to the controls was detected after 6hrs of
zinc treatment in both BPH and PC-3. Although no
significant zinc induction of MT1/2 in HPR-1, the
highest endogenous level of MT1/2 was found in
HPR-1, while PC-3 appeared to have the lowest
endogenous MT1/2. No endogenous MT3 mRNA
was detected in HPR-1 cells, whereas BPH cells
showed highest endogenous MT3 mRNA levels and
the amount of MT3 mRNA in PC-3 cells was 73%
less than that in BPH cells. A significant induction of
MT3 mRNA was determined as early as 6 hrs after
zinc treatment in BPH cells (215%) and 3hrs in PC-3
cells (292%) compared to their controls, but not in
HPR-1. Our results indicated that endogenous levels
and zinc regulation of MT1/2 and MT3 are cell type
specific. This study provides information of zinc
targeting MTs which may be a crucial event involved
in prostate tumorigenesis and tumor prevention.
The increased use of aminoglycosidic antibiotics has
accentuated the need for analytical methodology to
selectively and sensitively detect these compounds in
a wide variety of matrices. The direct detection of
aminoglycosidic antibiotics is inhibited by the lack of
an inherent chromophore and/or fluorophore. Preseparation derivatization procedures commonly used
to improve detection and chromatographic properties
are often complicated due to numerous derivatization
sites and multiple analogs of the antibiotics. These
compounds are typically considered to be
electroinactive under constant applied (dc) potential
conditions at solid electrodes. Pulsed electrochemical
detection (PED) following high performance liquid
chromatography (HPLC) has progressively developed
as a sensitive and reliable technique for the detection
of aminoglycosidic antibiotics as a result of low
detection limits and excellent reproducibility. An ionpairing reverse phase liquid chromatography method
with pulsed electrochemical detection has been
developed for the determination of aminoglycosidic
antibiotics. A C18 analytical column along with a
ODS-3 guard column are used with a mobile phase
rate of 1.00 mL/min at pH 3.2. Post column sodium
hydroxide was delivered to maintain a pH of ca. 13.
Detection was conducted using an optimized fourstep potential-time waveform by PED with a gold
working electrode.
Careful selection of PEDcompatible mobile phase constituents (i.e. organic
modifier and buffers) resulted in significant
improvements in system stability and reproducibility
(<3.5% RSD by peak area were achieved). Line
correlations >0.999 were obtained for all
compounds with significantly improved limits of
detection in the range of 30 ppb.
116. INVOLVEMENT OF TRANSCRIPTION
IN SOMATIC HYPERMUTATION
29th Annual Graduate Research Conference
Friday, April 20, 2007
29
Deepa Rajagopal, Patricia Gearhart, Ph.D.
Afternoon; Poster Presentation; MSTF Atrium
while electrically evoking synaptic responses from the
BLA. Observed responses were multiple component
depolarizing events. The fast onset of the response
(mean latency = 8 ms) suggests the response is
monosynaptic; however an inconsistent latency within
cells and a lack of cell firing implies a combination of
both excitatory and inhibitory polysynaptic events.
Artificial depolarization of recorded cells by current
injection did not typically result in cell firing but
instead revealed a reversal of the response. This
reversal strongly indicates that a feed-forward
mechanism is involved, which may employ networks
of local circuit interneurons. Future work is aimed at
investigating
local
GABAergic
interneuron
participation in the BLA evoked response.
Germinal centre B lymphocytes undergo somatic
hypermutation, a genetic diversification process used
to generate high-affinity antibodies with different
isotypes. The mutation pathway is initiated by
activation-induced cytidine deaminase (AID) protein,
which is expressed only in B cells. It is not clear what
targets mutation to the immunoglobulin loci. Genetic
evidence indicates that both promoter and enhancer
transcription
elements
are
required
for
hypermutation, implying that transcription might
somehow orchestrate AID recruitment. However,
the role of transcription in hypermutation has not
been characterized. To study targeting, I am taking a
fundamental approach to determine the pattern of
transcription in the mutating switch region compared
to the non-mutating constant gene. We generated
mutational map and transcriptional profile of the 5
Kb switch region spanning the S µ region promoter
through the C µ gene. Our results show that the
mutation pattern complies with transcription pattern
of the switch region, suggesting a role for
transcription in targeting AID to these regions
specifically.
118. AT CROSS-ROADS OF HEME
UTILIZATION AND QUORUM SENSING
Ajinder P Kaur and Angela Wilks
Afternoon; Poster Presentation; MSTF Atrium
Heme acquisition is a key process employed by
pathogenic bacteria to obtain iron from the host.
Pseudomonas aeruginosa genome has two distinct
heme uptake loci, phu (Pseudomonas heme uptake)
and has a heme assimilation system. In this study the
role of PhuS, a cytoplasmic heme binding protein
encoded by phu locus, was examined by
transcriptional profiling of a phuS transposon
insertion mutant. Disruption of phuS caused
premature induction of quorum sensing regulon,
evidenced in the form of early production of redox
pigment, pyocyanin during exit from logarithmic into
stationary phase. Surprisingly several iron-regulated
genes and the genes involved in transcriptional
regulation, post-translational modification and twocomponent signal transduction pathways were
differentially expressed. Additionally, several genes
involved in anaerobic mode of growth were downregulated. Although exact mechanism, by which
disruption of PhuS leads to such effects, is as yet
unknown, based on the microarray analysis several
potential cellular roles of PhuS emerge. These include
a potential role of PhuS in cellular homeostasis of
iron, magnesium and phosphate, and potential
protein-protein interactions of PhuS with quorum
117. AMYGDALA PROJECTIONS TO THE
PREFRONTAL CORTEX; AN INHIBITORY
GLUTAMATERGIC PATHWAY?
Jonathan E. Dilgen and Patricio O'Donnell
Afternoon; Poster Presentation; MSTF Atrium
The prefrontal cortex (PFC) and the amygdala are
important for goal directed behavior, learning and
reward related processes. Abnormal communication
between these structures has been implicated in drug
abuse, depression, PTSD, and schizophrenia.
Previous studies have shown that output neurons of
the basolateral amygdala (BLA) utilize excitatory
neurotransmitters, while others have shown an
inhibition of the PFC during BLA activation.
Questions remain about how this excitatory pathway
creates an inhibitory effect in post-synaptic cells. To
address these questions we recorded intracellularly
from PFC pyramidal neurons of anesthetized rats
29th Annual Graduate Research Conference
Friday, April 20, 2007
30
regulators such as RpoS, MvaT, RsmA or QscR.
Taken together the results presented will elucidate the
complex relationship between quorum sensing, iron
utilization and the intracellular heme status.
calibration and prediction errors. The same sample set
used to generate crushing strength calibration gave
SEC, SECV and SEP equal to 0.38, 0.47 and 0.5 kP
with R2 equal to 0.995, respectively. CONCLUSION
Study shows that NIR calibration prediction of
crushing strength is significantly affected by the range
of compression force.
119. QUALITY BY DESIGN: STUDY THE
RELATIONSHIP BETWEEN COMPRESSION
FORCE AND CRUSHING STRENGTH OF
THEOPHYLLINE TABLETS AND ITS
EFFECT ON NIR CALIBRATION AND
PREDICTION.
Vikas Moolchandani 1, Simin Hassannejad Tabasi 1,
Raafat Fahmy 2, Stephen W. Hoag 1, 1 School of
Pharmacy, University of Maryland, Baltimore, MD
21201
Afternoon; Poster Presentation; MSTF Atrium
120. NIMESULIDE, A COX-2 INHIBITOR,
REDUCES CEREBELLAR SYNAPTOPHYSIN
LEVELS IN MALE BUT NOT FEMALE PUPS
Shannon L. Dean and Margaret M. McCarthy
Afternoon; Poster Presentation; MSTF Atrium
The prostaglandins are well known for their role in
the production of fever and inflammation. Many
anti-inflammatories target this pathway by blocking
COX-2, the key enzyme in the production of
prostaglandins. However, prostaglandins also play an
important role in neuronal development and synapse
formation. Cerebella from male but not female rat
pups exposed to the selective COX-2 inhibitor
nimesulide show reduced levels of synaptophysin, a
presynaptic marker. This finding suggests that
prostaglandins play a role in the normal development
of the cerebellum as it does in other brain regions
such as the preoptic area of the hypothalamus. The
sex difference in vulnerability is intriguing given the
observation that several neurodevelopmental
disorders, including autism, present consistently with
cerebellar pathology and are also more prevalent in
males than females.
OBJECTIVE To study the relationship between
compression force and crushing
strength of
theophylline tablets and its effect on NIR calibration
and prediction. METHODS Tablets were pressed
using a Stokes B2 tablet press with compression
forces ranging from 235 to 2500 lb. Partial least
squares (PLS) calibrations were constructed to predict
the compression
force and crushing strength.
Statistical parameters such as standard error of
calibration (SEC), cross validation (SECV) and
prediction (SEP) were
compared, and the
nonlinearity and the effect of compression force vs.
crushing strength on PLS calibrations were evaluated.
RESULTS The plot of compression force vs.
crushing strength shows that tablets pressed with
compression forces ranging from 235-1500 lb
exhibited a linear correlation with crushing strength
and compression force from 1500 to 2500 lb, tablet
crushing strength plateaued and did not change
significantly. Using all the tablets pressed from 235 to
2500 lb, the best fit PLS calibration for compression
force gave a SEC, SECV and SEP equal to 133, 150
and 71 lb with a R2 of 0.953, and for crushing force
gave 1.17, 1.18 and 0.76 kP with R2 of 0.955,
respectively. However, when the calibration was
constructed using only the samples with compression
forces from 235 to 1500 lb, the SEC, SECV and SEP
decreased to 21, 38, 35 lb, and R2 increased to 0.997,
respectively, which is a significant improvement in
121. CHARACTERIZATION OF THE
BINDING SITE ON OBSCURIN FOR SMALL
ANKYRIN 1
B. Busby*, M. A. Borzok*, J. Nicholson, A.
Kontrogianni-Konstantopoulos#, and R. J. Bloch#
Afternoon; Poster Presentation; MSTF Atrium
Obscurin is a recently discovered ~800 kDa protein
of the titin superfamily that is expressed in striated
muscle, where it surrounds myofibrils at the levels of
the Z-disk and M-band. The localization of this
modular protein may allow it to link the contractile
apparatus to the sarcoplasmic reticulum (SR) of
29th Annual Graduate Research Conference
Friday, April 20, 2007
31
skeletal and cardiac muscle fibers. The C-terminus of
the molecule is localized near the SR and binds a
small protein spanning the SR membrane known as
small ankyrin 1 (sAnk1). We used the yeast twohybrid screen to identify a short sequence of amino
acids in obscurin that mediate binding to sAnk1
(6324-KWVEVEETIEVRVKK-6338) and sitedirected mutagenesis to identify the amino acids
involved in binding. Mutation of either K6324 or
K6338 to A reduces binding slightly, whereas
mutation to E inhibits binding significantly. Mutation
of each of the four E’s to A individually has little
effect; mutation of several inhibits binding
significantly; and mutation of all four completely
abolishes binding. The two central residues, E6329
and E6330, contribute most to these results. R6335A
has little effect on binding, whereas R6335E enhances
binding. Our results suggest that this sequence and
nearby amino acids, constitute a minimum binding
domain for sAnk1, and that electrostatic interactions,
mediated by positive charges flanking a highly
negatively charged core, contribute significantly to
binding. Supported by a grant to RJB from the NIH
(RO1 HL64304). A. Department of Physiology,
University of Maryland School of Medicine, Baltimore
B.
Department of Biochemistry, University of
Maryland School of Medicine, Baltimore
and eukaryotic systems and analyzed the protein
property in comparison with partially purified the
endogenous protein from brain tissue. Western blot
results revealed that PKCI/HINT1 from brain extract
has larger molecular size than E. coli recombinant.
The recombinant PKCI/HINT1 expressed in
eukaryotic system displayed same molecular size as
brain extract. This suggests that posttranscriptional
modifications could occur in PKCI/HINT1 which
may be important for its biological function. The
nature of posttranscriptional modifications on
PKCI/HINT1 is under investigation.
123. CHARMM DRUDE POLARIZABLE
FORCE FIELD FOR THE AROMATIC AND
HETEROCYCLIC COMPOUNDS
Pedro E. M. Lopes and Alexander D. MacKerell, Jr.
Afternoon; Poster Presentation; MSTF Atrium
The polarizable empirical CHARMM force field
based on the classical Drude oscillator has been
extended to aromatic and heterocyclic compounds,
including benzene, toluene, pyridine, pyrimidine and
indole. Optimization of all parameters was performed
against an extensive set of quantum mechanical and
experimental data. Ab initio data was used for
determination of the electrostatic parameters, the
vibrational analysis, and in the optimization of the
relative magnitudes of the Lennard-Jones parameters.
The absolute values of the Lennard-Jones parameters
were determined by comparing computed and
experimental heats of vaporization, molecular
volumes, free energies of hydration and dielectric
constants. The model includes atom-based
anisotropic polarizability and the presence of a lone
pair on the nitrogen atoms acting as hydrogen bond
acceptors. The newly developed parameter set was
extensively tested against additional experimental data
such as vibrational spectra in the condensed phase,
diffusion constants, heat capacities at constant
pressure and isothermal compressibilities including
data as a function of temperature. The structure of
the pure liquids was also studied.
122. STRUCTURAL CHARACTERIZATION
OF ENDOGENOUS AND RECOMBINANT
PKCI/HINT1 PROTEIN
Feng Bo, Porta Stefania. Jia Bei Wang
Afternoon; Poster Presentation; MSTF Atrium
PKCI/HINT1 is a member of the ubiquitous and
highly conserved protein family HIT and was firstly
reported as an inhibitor of PKC; however its actual
biological function is unknown. In vivo and in vitro
studies from our laboratory showed controversial
results on the PKC inhibiting activity of
PKCI/HINT1. This discrepancy may due to the
difference between endogenous and recombinant
PKCI/HINT1 proteins that was used in the in vitro
experiment. To elucidate the potential structural
differences and their putative effects on protein
function, we expressed PKCI/HINT1 in prokaryotic
124. EGb 761 ENHANCES ADULT
HIPPOCAMPAL NEUROGENESIS AND
29th Annual Graduate Research Conference
Friday, April 20, 2007
32
PHOSPHORYLATION OF CREB IN
TRANSGENIC MOUSE MODEL OF
ALZHEIMER’S DISEASE
Flaubert Tchantchou, Yanan Xu, Yanjue Wu, Yves
Christen, Yuan Luo
Afternoon; Poster Presentation; MSTF Atrium
The effects of alcohol consumption and its
subsequent metabolism on drug transport, absorption
and PK are poorly understood. We seek to examine
the effects of acetaldehyde (AcH) on the clinically
relevant drug transporter, PEPT1. Our hypothesis is
that the in vivo metabolism of EtOH and the
following AcH formation modulates the uptake
capacity of PEPT1 within the GI tract, for a variety of
clinically important peptidomimetic compounds.
Methodss: Glycylsarcosine (GlySar), a nonhydrolysable PEPT1 specific substrate was used and
in vitro uptake was performed in the CHO-hPEPT1
and Caco-2 cell models, measuring uptake of labeled
compound against unlabeled compound in the
presence of AcH. In vivo absorption of 3H-GlySar
was measured in SD rats that were treated orally with
ethanol (5 g/kg) for six days. Results: In vitro uptake
of 3H-GlySar in CHO-hPEPT1 cells treated with 1
mM AcH was significantly decreased as compared to
untreated controls. The uptake of 3H-GlySar in
Caco-2 cell monolayers treated with 1 mM AcH was
also significantly decreased as compared to the
untreated control cells. In vivo absorption of 3HGlySar in ethanol treated rats, as measured by AUC
were found to be 2-fold lower vs. the control group.
Conclusions: The effects of acetaldehyde due to
consumption of ethanol on the uptake and
bioavailability of therapeutic drug compounds
transported by PEPT1 have not been documented. In
the present studies, we demonstrate that AcH
significantly modulates PEPT1 function and, thereby,
drug bioavailability.
The standardized Ginkgo biloba extract (EGb 761)
exhibits beneficial effect to patients with Alzheimer
disease (AD). Previously, it has been demonstrated
that EGb 761 inhibits amyloid beta oligomerization in
vitro, protects neuronal cells against beta amyloid
toxicity and improves cognitive defect in a mice
model of AD (Tg 2576). Herein, We have examined
the neurogenic potential of EGb 761 and its effect on
cAMP response element binding protein (CREB), a
cell-signaling molecule that mediates neurogenesis, in
a double transgenic mice model (TgAPP/PS1). EGb
761 significantly increased cell proliferation in
hippocampus of the TgAPP/PS1 mice and of the old
wild type mice and also increased significantly, the
total number of developing neuronal stem cells in
vitro
in
a
dose-dependent
manner.
Immunofluorescence staining of neuronal marker
indicates that newly formed cells were neuronal
lineage. Furthermore, beta amyloid oligomers prohibit
phosphorylation of CREB and cell proliferation in
hippocampus
of
the
TgAPP/PS1
mice.
Administration of EGb 761 reduced those oligomers
and restored CREB phosphorylation in the
hippocampus of these mice. The present findings
suggest that 1) enhanced neurogenesis by EGb 761
may be mediated by activation of CREB, 2)
stimulating neurogenesis by EGb 761 may contribute
to its beneficial effect in cognitive functions in AD
patients and in the mice model of AD and 3) EGb
761 has therapeutic potential as a neurogenic agent
for the prevention and treatment of AD.
126. GABAERGIC CIRCUITRY MEDIATED
PREFRONTAL COGNITION
Gregory B Bissonette, Tejas Suresh, Mihyun Bae,
gabriela J Martins, Melissa K Brunckhorst, Theresa M
Franz Geoffrey M Schoenbaum, Elizabeth M Powell
Afternoon; Poster Presentation; MSTF Atrium
125. INVESTIGATING THE EFFECTS OF
ACETALDEHYDE ON THE
GASTROINTESTINAL OLIGOPEPTIDE
TRANSPORTER, PEPT1
Scott J. Fisher, Insong J. Lee, Peter W. Swaan, and
Natalie D. Eddington
Afternoon; Poster Presentation; MSTF Atrium
The advent of transgenic mouse models for human
diseases comes with a need for tests to probe these
models for elements of human cognition. We have
adapted a human Wisconsin Card Sorting Task
cognition test to a working mouse reversal/set-
29th Annual Graduate Research Conference
Friday, April 20, 2007
33
shifting paradigm. To further understand the
mechanisms underlying Autism Spectrum Disorder
(ASD) we tested a mouse model with inhibitory
GABAergic deficits on the mouse reversal/setshifting test. ASD in humans presents as social,
communication, and cognitive deficits which may be
partially mediated by altered prefrontal function. To
test if our model accurately depicts functional aspects
of ASD, we examined several lines of mice. In this
experiment, the mice were trained to discriminate, dig
for food based on different media or odor cues.
Correct dimensions were learned over repeated trials
using different sets of odors and media. After
performing these discriminations the mice were tested
on a reversal, where the previously correct stimuli
were now incorrect while maintaining the correct
dimension. The mice were then tested on an extradimensional shift where the previously correct and
incorrect dimensions were switched. The uPAR-/mice displayed less difficulty on the EDS relative to
wild-type mice. However, rescuing the GABAergic
neuronal loss in the uPAR-/-:GFAP-HGF/SF mouse
failed to rescue the cognitive phenotype, and indicates
a continued failure to form an attentional set. These
data suggest the cortical circuits that mediate certain
cognitive functions are anatomically fragile and simply
replacing the overall quantity of GABAergic
inhibition into the frontal cortex of the mouse is not
enough to rescue the uPAR-/-mouse phenotype.
Additional investigation will probe the signaling
systems of the prefrontal circuitry.
dephosphorylation of ATP. These metabolites are
able to be detected in urine 80, 60, and 40 hours after
consumption respectively. Using high performance
liquid chromatography coupled with conductivity
detection, we will be able to detect all three
metabolites in one chromatographic run. Previous
work in this laboratory group used pulsed
amperometric detection to detect ethyl-glucuronide, a
metabolite of alcohol. This work expands the
previous work by allowing the three metabolites, ethyl
sulfate, ethyl phosphate, and ethyl glucuronide to be
detected in a single chromatographic run. All three
metabolites are ionic in biological matrices, including
urine, making them ideal candidates for conductivity
detection. This poster will focus on the separation.
This will show the experimental design of the column
and detector system, investigate the separation of the
three metabolites, as well as the different analytical
figures of merit used to determine whether the
method is valid for the comparison of these analytes.
This project will have long standing effects in the
forensic science community by allowing detection of
alcohol intake from employees, students, recovering
alcoholics, and expectant mothers.
127. DETECTION OF ALCOHOL
METABOLITES IN URINE WITH HPLC
COUPLED WITH CONDUCTIVITY
DETECTION
Melinda Wilson, William R. LaCourse
Afternoon; Poster Presentation; MSTF Atrium
Introduction: Cardiac troponins are considered to be
the most sensitive and specific biomarker for the
diagnosis of MI. If there is a gender bias in the
diagnosis of MI, it could be reduced by more
consistently applying objective diagnostic criteria,
with consequent improved outcomes for women. The
purpose of this study was to assess accuracy and
predictive values of troponin assays in the diagnosis
of MI by gender and how various components of MI
diagnosis criteria relate to each other to predict MI
diagnosis. Methods: The study data was obtained
from the CHECKMATE study. It included 924
patients with possible myocardial ischemia. We
assessed the accuracy of baseline troponin using a
128. GENDER DIFFERENCES IN
ACCURACY OF TROPONIN ASSAYS IN
DIAGNOSIS AND TREATMENT OF
MYOCARDIAL INFARACTION
Azadeh Shoaibi and Dale Tavris
Afternoon; Poster Presentation; MSTF Atrium
Alcohol metabolizes in your system in two distinct
ways. Metabolism occurs via alcohol dehydrogenase.
This accounts for approximately 95% of the process.
The other 5% is processes of coupling reactions
through Phase II metabolism where alcohol is
coupled to glucuronides via UDP-glucuronidase,
sulfates via sulfotransferases, and phosphate via
29th Annual Graduate Research Conference
Friday, April 20, 2007
34
standard MI definition. We compared troponin
results with CK-MB and ECG results, and MI
classification and baseline troponin results with MI
discharge diagnosis and surgical treatment by gender.
Results: Of the 924 subjects, 125 had a definite MI
diagnosis. Baseline troponin was 44% sensitive and
97% specific in predicting MI, with no significant
difference by gender.
Baseline troponin was
positively associated with both ECG and CK-MB. MI
classification and rising or falling troponin were the
most accurate predictors of MI surgical treatment.
Surgical treatment for MI varied markedly by gender
when we controlled for MI category. Men were more
likely to be surgically treated than women.
Conclusions: Several surprising results from this pilot
study require focused analyses as we pursue a larger
study using a national MI registry database with
emphasis on attempting to understand gender
differences in the diagnosis and treatment of MI.
across all residential settings it can offer, how are
transitions in residential settings arrayed across time
and by select residential setting types? Is this stable
over time in cross-section as well as longitudinally?
130. CHARACTERISTICS OF ADVERSE
EVENT REPORTING FOR NARCOTIC AND
NON-NARCOTIC ANALGESICS
G Deshpande, S Weiss-Smith, A Tommasello, L
Simoni-Wastila, V Gogolak
Afternoon; Poster Presentation; MSTF Atrium
Pain is typically treated with one of the two drug
types: narcotic analgesics (NA) (scheduled drugs)
and/or non-narcotic analgesics (NNA) (available as
nonprescription and prescription). To compare and
contrast adverse event reports in narcotic and nonnarcotic analgesics suspected of adverse events (AEs)
reported to the US Food & Drug Administration
(FDA). All AEs reported in FDA Adverse Event
Reporting System (AERS) from Jan-00 through Mar06 with NA or NNA as the suspect cause were
identified. Study variables were report type, report
source, patient characteristics, reactions, and case
counts. Descriptive statistics, proportional reporting
ratios (PRR) were calculated. From the total AE
reports, 3.1% were identified for NA and 9% for
NNA as the suspect drug. The commonly reported
drugs were oxycodone (NA) and rofecoxib (NNA).
Only 9% of the NA reports came from consumers
compared to 13% of NNA. The most frequently
reported outcome among suspect NAs was death
while it was hospitalization for suspect NNAs. For
reactions by system organ class, the majority of
reports
obtained
for
NA
were
for
injury/poisoning/procedural
complications;
the
possibility of which for patients on NA is 2.3 times
greater compared to those on NNA. For NNA the
majority of the reports were classified under general
disorders/administration site conditions; reports of
which were 1.05 times greater for NNA than for NA.
Fully 12% of the AERS reports during this period
were identified with analgesics as the suspect cause.
This does not include those reports where analgesics
were used concomitantly. While given the widespread
usage and the severity of AEs, research is needed to
129. THE CONSISTENCY OF TRANSITIONS
IN RESIDENTIAL LIVING SETTINGS IN
MEDICARE BENEFICIARIES DURING 1998 2001
thomas shaffer, ilene zuckerman
Afternoon; Poster Presentation; MSTF Atrium
Since the mid-1980s many studies have been
undertaken looking at the specific transition of a
move from the community to a nursing home. There
have also been systematic reviews of these studies and
from the cumulative collection of this work (and
syntheses of them) admission to a NH from the
community has been found to be a function of many
individual risk factors such as lower levels of
cognitive ability, ADL limitations, behavioral
problems, and select health conditions such as
dementia or stroke (Miller and Weissert, 2000). The
trajectory or pathway of the transitions that result in
movement from the Community to Long-term care
settings is less known and hampered by data
collection complexities. Individuals are often “lost”
to data collection systems when they move from one
setting to another. Using the Medicare Current
Beneficiary Survey (MCBS) Residence Time Line file
(RIC 9) and the detailed enumerations of changes
29th Annual Graduate Research Conference
Friday, April 20, 2007
35
identify at risk patients and reduce the burden of
NA/NNA AEs.
132. UTILING EMPOWERMENT THEORY
TO EXPLAIN CHILD MALTREATMENT
Karen Castellanos-Brown
Afternoon; Poster Presentation; MSTF Atrium
131. THE IMPACT OF PATIENT
EDUCATION ON HBA1C VALUE
REDUCTION IN DIABETIC PATIENTS
N Samant and F Shaya
Afternoon; Poster Presentation; MSTF Atrium
About a million children a year are victims of child
maltreatment (Downs, Moore, McFadden, &
Costin, 2000). Child maltreatment is a broad term that
is used to apply to four major types of child
maltreatment: physical abuse, emotional abuse, sexual
abuse, and neglect (Wolfe, 1999; Downs et al., 2000;
Giovannoni, 1989). Despite advances in efforts to
curtail the prevalence of child maltreatment in the
United States, child maltreatment remains a
significant social problem impacting many children
and families in the United States each year. Research
indicates that the amount of substantiated cases of
child abuse and neglect has been on the rise (Downs
et al., 2000). In addition to negatively impacting the
children who are victims of the abuse and the family
members of the maltreated children, states are
economically impacted by the prevalence and
incidence of child maltreatment. Various theoretical
perspectives have been utilized to formulate
explanations for child maltreatment. One macro-level
theory that is central to social work is empowerment
theory. Empowerment theory focuses on the
structure of society as a means to explain social
problems. The social work literature appears to be
lacking a model applying empowerment theory to
child maltreatment. Thus, a model utilizing
empowerment theory to explain the social problem of
child maltreatment is presented.
Purpose: The purpose of this study was to assess the
impact of patient and physician education on
Hemoglobin A1c (HbA1c) control in diabetes
patients.
Methods: The analysis was based on a
subset of those enrolled in the Baltimore Partnership
Programs to Reduce Cardiovascular Disparities study
(UO1HL79151), with one year of follow-up. Patients
and their physicians were randomly assigned to either
intervention or control group, in a 2x2 nested casecontrol factorial design. Patients and physicians
participated in educational sessions. The 12-month
change in HbA1c, from baseline, was calculated, and
multiple regression used to assess the effects of
interventions on HbA1c change, adjusting for age,
race, gender and the presence of concomitant
hypertension. Results: Out of 590 total patients, 114
completed 12 month follow-up; most were African
American (96%) and female (62%), with mean
baseline HbA1c higher among males than females
(8.7% vs. 8.6%), African Americans than Caucasians
(8.7% vs. 8.15%), intervention patients than control
patients (9.15% vs. 8.28%), and patients of
intervention vs. control physicians (8.94% vs.8.33%).
The drop in the HbA1c values was greater among
intervention patients (-0.6 vs. 0.2) and patients of
intervention physicians (-0.32 vs. 0.01). After
controlling for age, race, gender and hypertension, the
drop in HbA1c in the patient intervention was greater
in intervention than in control patients, and greater in
the patients of intervention than in those of control
physicians.
Conclusions: In this patient sample,
greater drop in HbA1c is seen among the intervention
patients and patients of Intervention physicians.
These results highlight the influence of patient and
physician
interventions
supporting
diabetes
management programs.
133. CHARMM DRUDE POLARIZABLE
FORCE FIELD FOR THE ALCOHOL SERIES
Victor M. Anisimov, Benoît Roux, Alexander D.
MacKerell, Jr.
Morning; Poster Presentation; MSTF Atrium
A polarizable empirical force field based on the
classical Drude oscillator has been developed for the
aliphatic alcohol series. Transferability of the
developed parameters is ensured by the use of a single
electrostatic and Lennard-Jones model for the
hydroxyl group throughout the alcohol series. This
29th Annual Graduate Research Conference
Friday, April 20, 2007
36
work builds on the classical Drude polarizable models
developed for water [1], and the alkane series [2]. It
yields good agreement with pure solvent properties.
The polarizable model predicts gas-phase dipole
moment and interaction energies with water in
satisfactory agreement with experiment and QM
target data. This is a significant improvement over
45% overestimation of the corresponding properties
in the CHARMM22 fixed-charge additive model. The
polarizable model predicts pure solvent and aqueous
phase dipole moment distributions for ethanol
centered at 2.4 and 2.8 D, respectively, a significant
increase over the gas phase value of 1.8 D, whereas in
a solvent of lower polarity, benzene, a value of 1.9 is
obtained. [1] Lamoureux G.; Harder E.; Vorobyov
I.V.; Roux B.; MacKerell A.D.; Chem. Phys. Lett.
2006, 418(1-3), 245. [2] Vorobyov I.V.; Anisimov
V.M.; MacKerell A.D. Jr.; J. Phys. Chem. B 2005,
109(40), 18988.
our hypothesis. We have reported that siRNA
targeting obscurin in developing skeletal muscle cells
causes sAnk1 to fail to organize appropriately, leading
to a disruption of the network compartment of the
SR. Reduced expression of obscurin in cardiac
ventricular myocytes causes significant disruption of
Ca2+ signaling, compared with untreated cells,
consistent with an effect on the structure and
function of the SR. Preliminary results using siRNA
targeted to sAnk1 show disruption of the striated
organization of obscurin. Other sarcomeric proteins,
like alpha-actinin, remain well organized, however.
Our results suggest that reduced expression of sAnk1
or obscurin disrupts the sarcomeric alignment of the
network SR and perturbs Ca2+ cycling, . These
observations are consistent with our hypothesis that
sAnk1-obscurin binding plays an important role in the
coordinated organization of the network SR with the
myofibrillar cytoskeleton.
134. SMALL ANKYRIN 1 AND OBSCRUIN:
ORGANIZING THE SARCOPLASMIC
RETICULUM AROUND THE
CONTRACTILE APPARATUS OF STRIATED
MUSCLE.
Maegen A. Borzok, Andrew Ziman, Aikaterini
Kontrogianni-Konstantopoulos,
W.
Jonathan
Lederer, Robert J. Bloch
Morning; Poster Presentation; MSTF Atrium
135. KINETIC ANALYSIS OF THE REMOVAL
OF HALOGENATED URACIL BY HUMAN
THYMINE DNA GLYCOSYLASE. EFFECTS
OF ALTERING THE CPG SITE CONTEXT
Michael Morgan, Matthew Bennet, and Alex Drohat
Morning; Poster Presentation; MSTF Atrium
DNA Glycosylases hydrolytically excise damaged or
mismatched bases from DNA. hTDG (human
thymidine DNA glycosylase), is active against G∙T
mispairs and other lesions. We have shown that 5fluorouracil (FU), as well as its 5-chlorouracil (ClU)
and 5-bromouracil (BrU) are excised much faster than
the traditional G∙T substrate (Bennett, M.T., et al
JACS 128, 12510-12519). Previous studies indicate
that hTDG is specific for lesions paired with G and
located at CpG sites. We investigated the contribution
of the 5’-base pair to hTDG activity using single
turnover kinetics with substrates containing FU, ClU,
and BrU lesions. For ClU, kmax was 10-fold lower
for GpG∙ClU, 5-fold lower for TpG∙ClU, and 85-fold
lower for ApG∙ClU as compared to CpG∙ClU. Similar
trends were observed for FU and BrU. Our findings
indicate that hTDG is more active against FU∙G,
ClU∙G, and BrU∙G lesions in any DNA context than
against CpG∙T lesions. Thus, hTDG may offer
Each sarcomere of striated muscle is encircled by a
compartment of the sarcoplasmic reticulum (SR) that
is responsible for storing Ca2+ -- the “network SR”.
The interactions that align the network SR with the
contractile apparatus are poorly understood. We have
hypothesized that the binding of two proteins, small
ankyrin 1 (sAnk1), an integral protein of the network
SR membrane, and obscurin, a giant (~800 kDa)
protein that surrounds the sarcomere, is necessary for
alignment. sAnk1 binds obscurin with nM affinity,
and colocalizes with it at the periphery of sarcomeres,
but a role for their binding in aligning the network SR
has not been firmly established. We have used small
inhibitory RNA (siRNA) technology to knock down
both obscurin and sAnk1 in primary cultures of
differentiating skeletal and cardiac myocytes to test
29th Annual Graduate Research Conference
Friday, April 20, 2007
37
general protection against ClU∙G and BrU∙G lesions,
which may arise in DNA at sites of inflammation.
However, the much slower activity for FU∙A, ClU∙A,
and BrU∙A pairs suggests a limited protective role for
hTDG against these lesions.
137. GESTATIONAL-INDUCED
ALTERATIONS IN BRAIN DISTRIBUTION
OF THE P-GP SUBSTRATES, SAQUINAVIR
AND METHADONE, IN MICE
Lisa D. Coles, Insong J. Lee, Hazem E. Hassan,
Natalie D. Eddington
Morning; Poster Presentation; MSTF Atrium
136. BILOBILIDE AND QUECERTIN
ALLEVIATE IMPAIRED BNDF
EXPRESSION AND CREB
PHOSPHORYLATION INDUCED BY
EXTRACELULAR A? OLIGOMERS IN
TRANSGENIC NEUROBLASTOMA CELLS
Yanan Xu, Yuan Luo
Morning; Poster Presentation; MSTF Atrium
The transporter, P-glycoprotein (P-gp), plays a critical
role in the maternal-to-fetal and blood-to-brain
transfer of certain drugs. Furthermore, the expression
of P-gp in placental tissue has been shown to vary
with gestation age. Using a mouse model, the effect
of gestational age on maternal-to-fetal and blood-tobrain transport of the P-gp substrates, [3H]saquinavir
and [3H]methadone was evaluated. For these studies,
[3H]saquinavir and [3H]methadone concentrations
were measured in plasma, brain, placenta, and fetal
samples collected 15 and 60 min following i.v. dosing
to pregnant (gestation day (gd) 13 and 18) and virgin
mice. Additionally, P-gp protein and mdr1 mRNA
levels were determined in the placenta and brain by
Western Blotting and quantitative real time RT-PCR.
Following i.v. administration, fetal exposures to
[3H]saquinavir were similar at gd 13 and 18 despite a
2-fold increase in placental uptake at gd 18 compared
to 13 and greater P-gp levels in the placenta of mice
at gd 13 (p<0.05). Yet, mice at gd 18 experienced a
2- to 3-fold increase in [3H]saquinavir and
[3H]methadone brain:plasma ratios at 60 min
postdose relative to mice at gd 13 (p<0.05).
Moreover, variable P-gp protein levels were observed
in the brain with the greatest levels at gd 13, which
likely contributes to the gestational-induced changes
in saquinavir and methadone brain distribution.
Despite different levels of P-gp protein at these
gestational stages, no statistical difference was
observed in brain and placental mdr1a and mdr1b
mRNA levels. Indeed, altered exposure to the brain
during pregnancy may greatly impact the clinical
outcomes of drugs used by pregnant women to treat
diseases such as depression, epilepsy, HIV and opiate
addiction.
The amyloid beta (Aβ) oligomers is thought to be the
major cause for the early pathological events in
Alzheimer’s disease (AD) which is characterized by
synaptic dysfunction followed by memory loss.
Several molecular biomarkers have been linked to the
neuroplasticity, including brain derived neurotrophic
factor (BDNF) and the cAMP element response
binding protein (CREB), both have been reported to
be reduced in the AD brain. In this study, quecertin
and bilobalide B, two components of EGb761 which
is shown to be beneficial to AD patients, were studied
to explore whether the beneficial effect on
neuroplasticity is mediated by the CREB/BDNF
signaling pathway. When we cultured the wide type
neuroblastoma cells in a conditioned medium
containing Aβ secreted from mutant neuroblastoma
cells, a decrease level of BDNF and pCREB were
observed. This was reversed by depleting Abeta
oligmers via adding oligmer specific antibody
suggesting that extra cellular Abeta oligmers impair
the level of BDNF and pCREB. Using
immunostaining, Western blotting and real-time PCR,
we found that these two compounds enhanced the
phosphorylated level of CREB and the expression
level of BDNF which were lowered in the transgenic
neuroblastoma expressing Aβ. The potential pathways
which may mediate the enhanced expression of
BDNF by quecertin and bilobilide B, were explored
by the use of specific inhibitors.
29th Annual Graduate Research Conference
Friday, April 20, 2007
38
138. ASSESSMENT OF NASAL SPRAY
DEPOSITION IN A NOSE MODEL USING
COLORIMETRIC TECHNIQUES
Vipra Kundoor and Richard Dalby
Morning; Poster Presentation; MSTF Atrium
Gabriela J. Martins, Céline Plachez, Elizabeth M.
Powell
Morning; Poster Presentation; MSTF Atrium
Hippocampal interneurons arise in the ventral
forebrain and migrate dorsally in response to cues,
including hepatocyte growth factor/scatter factor
(HGF/SF) which signals via its receptor MET.
Examination of the hippocampus in adult mice in
which MET was inactivated in the embryonic
proliferative zones showed an increase in
parvalbumin-expressing cells in the dentate gyrus, but
a loss of these cells in the CA3 region. An overall
loss of calretinin-expressing cells was seen throughout
the hippocampus.
A similar CA3 deficit of
parvalbumin and calretinin cells was observed when
MET was eliminated only in postmitotic cells. These
data suggest that MET is required for the proper
hippocampal
development,
and
embryonic
perturbations lead to long term anatomical defects
with possible learning and memory dysfunction.
Aqueous nasal sprays are widely used to treat patients
with local diseases such as allergic rhinitis. Several
nasally administered corticosteroid products are
nearing patent expiration and are candidates for
generic copies, which is driving interest in how
bioequivalence will be established – possibly using in
vitro methodology capable of elucidating the droplet
deposition site of test and reference products. This
has been attempted using clinical, scintigraphic and
computational fluid dynamics modeling, but these
methods each have specific limitations. The purpose
of this study was to overcome these limitations using
inexpensive and uncomplicated methods to assess the
site of initial nasal spray deposition within
anatomically correct silicone human nose models.
Several colorimetric techniques to visualize the site of
droplet deposition were evaluated, culminating in the
identification of turmeric and Sargel as possible
indicators. Turmeric, a natural acid-base indicator
which is yellow at pH 7.0, but intensely red at pH 8.4,
is incorporated into a base of KY Gel and acetone (to
allow uniform spreading without beating on the
interior of the nose model; ratio 0.06:1:1w/w) and
was evaluated for its sensitivity to 0.3M NaOH
solution deposited on its surface using a nasal spray.
Sargel is a commercial water level-indicating paste
which turns from white to purple on contact with
water. Changes in color were captured using a digital
camera under standardized photographic conditions,
and the images were analyzed using Adobe
photoshop. There was a significant change from
yellow to red and white to purple upon nasal spray
deposition with turmeric and Sargel respectively.
Sargel was found to be more robust compared to
turmeric, as it did not require product adulteration.
140. OVEREXPRESSING HGF/SF RECOVERS
INTERNEURON DEFECTS AND SEIZURE
BEHAVIOR OF THE uPAR NULL MICE
Mihyun Bae, Melissa Brunckhorst, Wendy M. Mars,
George K. Michalopoulos, Cristian Achim, and
Elizabeth M. Powell
Morning; Poster Presentation; MSTF Atrium
Interneuron development is tightly regulated by
molecular cues including hepatocyte growth
factor/scatter factor (HGF/SF). HGF/SF signals via
its receptor MET to promote cellular survival,
differentiation, mitogenesis and migration dependent
upon cellular context. HGF/SF, which is secreted as a
single chain precursor form, must be cleaved for
biological function by proteases such as urokinase
plasminogen activator (uPA). uPAR, the receptor of
uPA, efficiently increases the protease cleavage by
uPA. Adult uPAR-/- mice have decreased numbers of
neocortical GABAergic interneurons and severe
behavioral dysfunction such as spontaneously
generated seizure and susceptibility to PTZ
(pentylenetretrazol, a GABA antagonist)-induced
seizure. The loss of interneurons in the uPAR-/-
139. LOSS OF EMBRYONIC MET
SIGNALING ALTERS PROFILES OF
HIPPOCAMPAL INTERNEURONS
29th Annual Graduate Research Conference
Friday, April 20, 2007
39
mouse is restored in uPAR-/-:GFAP-Hgf mouse, in
which the uPAR-/- mouse was bred with an HGFoverexpressing mouse line (GFAP-Hgf). The seizure
susceptibility to PTZ of uPAR-/- mice is decreased in
the uPAR-/-:GFAP-Hgf mouse. The latency to
seizure activity after PTZ treatment is also increased
in the uPAR -/-:GFAP-Hgf mouse as compared to
the wildtype mouse. These data suggest that restoring
HGF/SF levels can recover the anatomical
interneuron defects and neocortical circuitry, leading
to prevention of the seizure activity. This study is
supported by Epilepsy Foundation (MB and EMP)
and Autism Speaks – NAAR (EMP).
we show that hTDG-core is not inhibited by the
substrate bases uracil or thymine at up to 5 mM
concentrations. In contrast, hTDG-core is inhibited
by duplex DNA containing a stable dU analog and by
DNA containing a central CpG site.
142. MOLECULAR DETERMINANTS OF
LOCAL CALCIUM SIGNALS IN SKELETAL
MUSCLE
Luke Michaelson, Dr. Christopher Ward
Morning; Poster Presentation; MSTF Atrium
Calcium (Ca2+) sparks are spatially restricted Ca2+
transients arising from a cluster of RyR’s that are
locally activated by calcium induced calcium release
(CICR). In myofibers loaded with the Ca2+ indicator
dye fluo-4, Ca2+ sparks appear as brief (a few msec.) ,
spatially restricted (a few µm) fluorescent transients.
In the heart Ca2+ sparks summate to form the basis
for the global voltage elicited Ca2+ transient. In
intact adult mammalian myofibers, any resolvable
Ca2+ spark type release is absent both at rest and
during voltage activated EC coupling. In fact, It is
now accepted that in healthy, intact, adult mammalian
skeletal muscle, “Ca2+ spark” type release is
suppressed in favor of a tight control of Ca2+ release.
Recent reports indicate that Ca2+ sparks are revealed
following acute membrane stress or in
pathophysiologic conditions (muscular dystrophy,
aged muscle, muscle injury) however the mechanistic
basis is not clear. Based on our current work we
hypothesize that a local disruption in the DHPR
suppression of the RyR (i.e., sub-cellular damage)
creates the “potential” for a Ca2+ spark to occur and
the stress/disease related increase in the release of
physiological RyR agonists initiates the Ca2+ sparks
behavior. In this investigation we demonstrate that
experimental myofiber stress promotes the increase of
two RyR agonists in the myoplasm; Ca2+ and reactive
O2 (ROS); both potent activators of RyR release.
Furthermore, we have preliminary evidence to suggest
that Ca2+ sparks can be modulated by these
mediators in a physiologic and disease relevant
manner.
141. STEADY-STATE KINETICS OF HUMAN
THYMINE DNA GLYCOSYLASE (HTDG)
USING A COUPLED-ENZYME ASSAY:
IMPLICATIONS FOR THE MECHANISM OF
HTDG STIMULATION BY HUMAN AP
ENDONUCLEASE 1.
Megan E. Fitzgerald and Alexander C. Drohat
Morning; Poster Presentation; MSTF Atrium
DNA glycosylases initiate base excision repair by
removing damaged or mismatched bases, producing
an abasic (AP) site in the DNA. Many glycosylases
bind the AP DNA product tightly, impeding
enzymatic turnover. Human thymine DNA
glycosylase (hTDG), which recognizes G•T mispairs
and other mutagenic lesions, exhibits severe product
inhibition, precluding the use of steady-state kinetics
to study its catalytic mechanism. To overcome this
problem, we developed a coupled enzyme assay
where the second enzyme, human AP endonuclease
(hAPE1), stimulates the turnover of hTDG. The
coupled reaction is monitored continuously by
fluorescence spectroscopy. We determined the steadystate kinetic parameters for hTDG, and its catalytic
core (hTDG-core, Phe111 to Val308) against a G•U
substrate. We find that hAPE1 enhances the steady
state turnover (kcat) of hTDG and hTDG-core by
about 15-fold and 100-fold, respectively, and that
hAPE1 actively displaces AP DNA from hTDG and
hTDG-core. Thus, the 110 N-terminal residues and
102 C-terminal residues of hTDG are not required for
its stimulation by hAPE1. Using the coupled assay,
29th Annual Graduate Research Conference
Friday, April 20, 2007
40
143. METAL-DEPENDENT REGULATORS
AND THEIR ROLE IN OXIDATIVE STRESS
RESPONSE IN ENTEROCOCCUS FAECALIS
Sehmi Paik and Diana M. Oram
Morning; Poster Presentation; MSTF Atrium
Morning; Poster Presentation; MSTF Atrium
All-trans-retinoic acid (ATRA), a metabolite of
vitamin A, is required for growth and other biological
functions in the body. ATRA is metabolized by
cytochrome P450 enzymes. ATRA levels are lower in
prostate carcinoma when compared to a healthy
prostate or BPH. Compounds which block this P450
mediated catabolism of ATRA have been developed
to increase its endogenous levels. These agents,
termed retinoic acid metabolism blocking agents
(RAMBAs) have been found to inhibit the growth of
various prostate cancer cell lines in vitro and in vivo.
A novel RAMBA, VN/66-1 in combination with MS275, a histone deacetylase inhibitor (now in phase II
clinical trials), has been found to have a synergistic
growth inhibitory effect in hormone refractory human
prostate cancer cells (PC-3).
The IC50 of the
combination for PC-3 cell viability was less than 1.0
nM, much lower than the IC50 values for VN/66-1
(1.8 uM) or MS-275 (0.302 uM) alone (p ≤; 0.0001).
The combination index for VN/66-1 + MS-275 was
found to be 0.3, indicative of synergism.
Furthermore, the combination induced a G2 phase
arrest of the cell cycle, apoptosis and DNA damage
(γ-H2AX foci). The combination was also more
effective in reactivating RARb, a tumor suppressor
gene silenced in PC-3 cells. Additionally, VN/66-1 in
combination with MS-275 inhibited PC-3 tumor
xenograft growth much more effectively than either
agent alone. The combination treatment (VN/66-1,
10 mg/kg + MS-275, 2.5 mg/kg) (s.c. QD) was
significantly different from the control (p < 0.05)
and inhibited tumor growth by 85% in male SCID
mice.
These results reveal that VN/66-1 in
combination with MS-275 is extremely potent and
may be a potential new treatment for both hormone
sensitive and hormone refractory prostate cancer.
Enterococcus faecalis is a Gram positive facultative
anaerobe and is routinely associated with the human
intestinal microflora. However, E. faecalis is also an
opportunistic pathogen and has been reported as an
etiologic agent in various nosocomial infections. E.
faecalis is halotolerant, bile-resistant and known to
have a relatively high-level intrinsic resistance to many
antibiotics. Additionally, the incidence of vancomycin
resistant enterococcal infections is increasing.
Therefore, it is important to better understand the
pathogenesis of enterococci in order to identify more
virulence factors and develop new therapeutic
measures. The ability of a pathogen to respond to
oxidative stress is an important virulence factor and
there has been increasing recognition of the role of
metal-dependent regulators in oxidative stress
response and bacterial pathogenesis. The most
extensively studied metal-dependent transcriptional
regulators are DtxR in C. diphtheriae and Fur in E.
coli. The completed genome sequence of E. faecalis
V583 strain revealed that there are several genes
predicted to encode metal-dependent regulators from
both the DtxR-like and Fur-like family. Three of
these genes were selected for our study; EF1005,
EF1525, and EF2417. To investigate the role of these
regulators in E. faecalis, a new genetic approach,
developed by Kristich et al (Plasmid, 2006), using
markerless exchange to construct a deletion mutant
was adapted. The construction of these mutants using
a laboratory strain, OG1RF, as a host is in progress.
Following construction, the role of the deleted genes
will be characterized with attention to the oxidative
stress response and metal-dependent transcriptional
regulation in E. faecalis.
145. DEVELOPMENT OF PARAMETERS
FOR THE CHARMM GENERAL FORCE
FIELD (CGENFF)
Kenno Vanommeslaeghe; Chayan Acharya; Alexander
D. MacKerell, Jr.
Morning; Poster Presentation; MSTF Atrium
144. VN/66-1 AND MS-275
SYNERGISTICALLY INHIBIT HORMONE
REFACTORY PROSTATE CANCER
GROWTH
Aakanksha Khandelwal, Vincent C. O. Njar
29th Annual Graduate Research Conference
Friday, April 20, 2007
41
Empirical force fields are presently the only
computational methods fast enough to routinely
perform molecular dynamics simulations of large
molecular systems such as proteins on relevant time
scales. The CHARMM set of force fields is currently
capable of representing, among others, proteins,
nucleic acids, lipids, and carbohydrates. Consequently,
it is widely used for simulating biomolecular systems.
Nevertheless, its usefulness for computer-aided drug
design is limited because it does not support drug-like
molecules in general. The CHARMM General Force
Field (CGenFF) aims to fill this void. It will feature
force field parameters for moieties commonly
encountered in drug-like molecules, as well as generic
parameters and a charge assignment scheme for
functional groups that are not explicitly covered. As a
first step, force field parameters and charges for
moieties commonly encountered in drug-like
molecules are developed. However, this class of
compounds covers a broad chemicals space, whereas
biomolecular systems only contained a limited variety
of functional groups. This difference prompted us to
use a slightly modified parameterization procedure,
while staying consistent with the general philosophy
for parameter development in CHARMM. Specific
problems encountered during the CGenFF
parameterization and the solutions we developed will
be discussed.
weather the effect of EGb 761 is due to a direct
acting on Abeta oligomers or indirectly affecting a
common protective mechanism, we probe EGb
effects on small heat shock protein 16.2 (sHSP16.2), a
chaperon protein associated with intracellular Abeta
expression, in the C. elegans model.
By coimmunoprecipitation, we found that feeding with
EGb 761 reduced sHSP16.2 associated with Aβ.
Furthermore, we down regulated sHSP16.2 by
dsRNA interference (dsRNAi) of sHSP16.2 and
performed the paralysis assay for Abeta-induced
toxicity in the transgenic C. elegans. Our results
demonstrate a more profound delay of paralysis in
worms fed with EGb 761 and dsRNAi than feeding
with either one alone. We also found that the worms
fed with dsRNAi exhibited decreased level of
hydrogen peroxide (H2O2). These results suggest that
Abeta expression induced the levels of H2O2 and
sHSP16.2 in the transgenic C. elegans and both were
attenuated by EGb 761. The result is consistent with
our previous report that sHSP16.2 induced by an prooxidant were remarkably suppressed by EGb 761
(supported by NIH/NCCAM ATRO1AT00928-03
and IPSEN France).
147. STRUCTURE/FUNCTION STUDIES ON
S100A1
Nathan Wright, Benjamin Prosser, Kristen Varney,
Martin Schneider, and David Weber
Morning; Poster Presentation; MSTF Atrium
146. GINKGO BILOBA LEAF EXTRACT EGB
761 REDUCES SMALL HEAT SHOCK
PROTEIN ASSOCIATED WITH
INTRACELLULAR A? IN TRANSGENIC C.
ELEGANS MODEL
Yanjue Wu, Wail Hassan, Chris Link, Yuan Luo
Morning; Poster Presentation; MSTF Atrium
S100A1 is an EF-hand-containing Ca(2+)-binding
protein that undergoes a conformational change upon
binding calcium as is necessary to interact with
protein targets and initiate a biological response in
muscle cells. The recently-solved solution structure
of Ca-S100A1 shows a large, hydrophobic pocket that
is hidden in the apo form of the protein. This region
is suspected to be the target protein interaction
domain. Here, we build on previous structural work
to begin investigating what proteins interact with
S100A1, what structural elements are involved in
target protein binding, and how S100A1, by binding
to its target proteins, influences the characteristics of
skeletal muscle cells.
Ginkgo biloba leaf extract EGb 761 has been
demonstrated to have beneficial effects on dementia
in Alzheimer’s disease (AD). In the pathogenesis of
AD, amyloid-β (Aβ) aggregation plays an important
role. Previously we have shown that ginkgo biloba
leaf extract EGb 761 inhibits Aβ oligomerization in a
transgenic cell line expressing Abeta. We recently
observed a reduced Aβ toxicity and Aβ oligomers in a
transgenic C. elegans model. In order to determine
29th Annual Graduate Research Conference
Friday, April 20, 2007
42
148. THE ROLE OF A FUR-LIKE GENE IN
CORYNEBACTERIUM DIPHTHERIAE
METALLOREGULATION
K. F. Smith, J. E. Woolston, D. M. Oram
Morning; Poster Presentation; MSTF Atrium
ACTIVATION OF TRANSLATION
INHIBITORS
Robert Bruno
Morning; Poster Presentation; MSTF Atrium
VN/124-1 is a steroidal 17-benzoimadazole rationally
designed by our group as an inhibitor of CYP17 for
the treatment of advanced prostate cancer (PCA).
The compound was subsequently found to act as an
androgen receptor (AR) antagonist. Superior in-vivo
efficacy over castration lead us to examine whether or
not the compound had any anti-cancer effects
independent of the androgen receptor. We now
report that VN/124-1, and related compounds,
inhibit the growth of AR negative PCA cells (PC3 and
DU-145) equally as well as AR positive PCA cells
(LNCaP and LNCaP-C81). The compound inhibited
the growth of normal fibroblasts at concentrations 5
fold greater than PCA cancer lines. VN/124-1 was
found to be cytostatic and not cytotoxic up to 20µM
and arrested cells in the G1/G0 phase. Microarray
and real time PCR assays demonstrated an upregulation of genes involved in response to cellular
stress including unfolded protein response genes
asparagine synthase, activating transcription factors 3
and 4 as well as eukaryotic translation initiation factor
4 binding protein 1 (4EBP1). Finally, VN/124-1
treatment results in phosphorylation of eukaryotic
translation initiation factor alpha (eIF2α) and downregulation of cyclin D1 protein without a change in
mRNA levels further suggesting activation of the
unfolded protein response. Taken together, these
results suggest VN/124-1 exhibits direct cytostatic
effects via the combined inhibition of translation
through activation of eIF2α and up-regulation of
4EBP1 resulting in the arrest of cancer cells in the
G1/G0 phase of cell cycle.
Metals are essential yet toxic at high concentrations,
therefore, strict regulation of uptake is critical.
Homologs of the ferric uptake regulator Fur and the
diphtheria toxin repressor DtxR regulate transcription
in response to iron (Fe), zinc (Zn), manganese (Mn),
or peroxide stress in many bacterial species. C.
diphtheriae contains two DtxR-like proteins (one Fedependent and one Mn-dependent) and a fur-like
gene whose function is unknown. Located upstream
of fur is a gene encoding a member of yet another
family of metal-dependent regulators exemplified by
ArsR. We hypothesize that Fur is a member of a
sophisticated network of transcriptional regulators,
which controls gene expression in response to metalinduced stresses. We have constructed a C.
diphtheriae strain in which fur was inactivated. We
performed growth curves comparing wild-type C.
diphtheriae to the δfur strain in Fe replete and
depleted conditions. We observed no significant
difference in growth between strains in differential Fe
conditions suggesting that the fur-like gene does not
play a critical role in controlling Fe uptake. To assay
promoter activity, we cloned the regions upstream of
fur and arsR into a reporter plasmid. We identified
two promoters; P-arsR which functions both in E.
coli and C. diphtheriae and P-fur which is active only
in C. diphtheriae. In quantitative assays, P-arsR and Pfur were shown to be constitutive in response to Fe,
Mn, Zn, and Cu. With bioinfomatics we identified
two possible Fur binding sites in the C. diphtheriae
genome. The DNA fragments containing the Fur
binding sites were subsequently cloned to determine if
these regions contain promoters are regulated by Fur.
These studies will help to further investigate the
intricacies of metal regulation in Gram+ bacteria.
150. PKCI/HINT1 KNOCKOUT MICE: A
MODEL FOR PSYCHOLOGICAL DISEASES?
Elisabeth Barbier PhD, Bo Feng MS & Jia Bei
Wang MD PhD
Morning; Poster Presentation; MSTF Atrium
149. NOVEL CYP17 INHIBITOR VN/124-1
DIRECTLY INHIBITS GROWTH OF
PROSTATE CANCER CELLS VIA
Protein kinase C interacting protein (PKCI/HINT1)
is a small protein belonging to the hit family proteins.
29th Annual Graduate Research Conference
Friday, April 20, 2007
43
Its physiological function is currently unknown.
Decrease in PKCI/HINT1 expression has been
demonstrated in prefrontal cortex of schizophrenic
patients (Vawter et al 2002, 2004). Our laboratory
found that KO mice present one positive symptom of
schizophrenia when administered with Damphetamine, displaying higher ambulation and
stereotypy compared to the WT in the open field test
(Barbier et al 2007). These data suggest that
PKCI/HINT1 may play a role in the neuropathology
of schizophrenia. To further our study we conducted
a battery of behavioral tests assessing depression and
anxiety traits, social approach and relationship with
psychosis. In addition, using G-protein coupling assay
we probed what neurotransmitter system is involved.
We found that compared to their wild type
littermates, the PKCI KO mice exhibit significant
difference in the behavioral tests. In the forced swim
and the tail suspension tests KO mice showed less
immobility, in the light/dark box test they spend
more time in the lit compartment. Moreover KO
mice manifested less social approach, which is one
negative symptom of schizophrenia in animal model.
Results from GTPγS binding probing the
dopaminergic system suggest that PKCI/HINT1
might affect the dopaminergic system at the D2 level.
Taken together our results imply that PKCI/HINT1
KO mice might be an animal model for studying
psychological
disorders
and
in
particular
schizophrenia. This discovery is the object of a
pending patent (JW2006-042PCT).
apical sodium dependent bile acid transporter
(hASBT, SLC10A2) belongs to the solute carrier
family of transporters and is primarily expressed in
small intestine. hASBT plays a critical role in
enterohepatic recirculation of bile acids by active
reabsorption of them from ileum with an efficiency of
over 97%. It suggests that hASBT can be used as a
drug or prodrug target for enhancing drug uptake in
the intestine. In addition, published data show that
drugs may be conjugated to the bile acid’s C-24
carboxylate to yield prodrugs that are transported by
hASBT to improve oral drug bioavailability. To
rationally exploit hASBT for improving drug uptake
we have systematically developed a structure-activity
relationship to reveal the chemistry space of bile
acid’s C-24 side chain region that allows bile acid
conjugates to be translocated by hASBT. The work
applies a novel molecular modeling approach that
considers conformational distribution patterns,
deemed a conformationally sampled pharmacophore,
to develop a pharmacophore model and a predictive
three dimensional quantitative structure-activity
relationship (3D-QSAR) model. Results from
application of the approach to a training set of
representative bile acids will be presented.
151. SUBSTRATE REQUIREMENTS FOR
HUMAN APICAL SODIUM DEPENDENT
BILE ACID TRANSPORTER (hASBT,
SLC10A2): A RATIONAL APPROACH TO
PRODRUG DESIGN
Chayan Acharya, James E. Polli, Alexander D.
MacKerell, Jr.
Morning; Poster Presentation; MSTF Atrium
Serotonin (5-hydroxytryptamine; 5-HT) is a
monoamine that modulates behaviors in both
invertebrates and vertebrates. Drugs that alter 5-HT
signaling are potent antidepressants and affect
metabolic rates. Previously, our laboratory has shown
that the Ginkgo biloba extract EGb 761 modulates
the expression of 5-HT2A receptors in N2A
neuroblastoma cells expressing amyloid beta and it
enhances adult neurogenesis in aged mice in the
mouse model of Alzheimer’s disease. The aim of the
present study is to determine the mechanism of action
of EGb 761 on 5-HT transmission. In the nematode
Caenorhabditis elegans, exogenous 5-HT regulates
several different behaviors including: egg-laying,
152. MODULATION OF SEROTONIN
NEUROTRANSMISSION BY EGB 761 IN
C.ELEGANS
Marishka Brown and Yuan Luo
Morning; Poster Presentation; MSTF Atrium
Low intestinal permeability is one of the major
problems in the development of novel drug
candidates. The prodrug approach can reduce this
problem by targeting membrane transporters in the
small intestine to facilitate drug uptake. The human
29th Annual Graduate Research Conference
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44
pharyngeal pumping and locomotion. It has been
shown that 5-HT regulates movement through
MOD-1, which is a 5-HT gated chlorine channel
found in the worms. When exogenous 5-HT is
applied to wild type worms this causes a decrease in
locomotion. Mutant mod-1 worms are resistant to
levels of exogenous 5-HT. In this study, wild-type and
mutant mod-1 worms were treated with EGb 761 in
the presence or absence of known 5-HT agonist and
antagonist. Our results show that wild type worms
treated with EGb 761 have a similar resistance to
exogenous 5-HT and this is dependent on MOD-1.
However, mod-1 worms that are treated with EGb
761 are less resistant to exogenous 5-HT. The
question of whether the modifying effects of EGb
761 on 5-HT receptors are direct or indirect is
presently under investigation.
concentrations of different antidepressants on the
levels of [3H]cytidine-labeled CDP-diacylglycerol
accumulation in PC12 cells. The drugs tested include
the tricyclic antidepressant imipramine, atypical
antidepressant maprotiline and selective serotonin
reutake inhibitor paroxetine. Results: Different
antidepressants directly and dose-dependently
increased the levels of CDP-diacylglycerol
accumulation in PC12 cells. Conclusions: These data
suggest the involvement of CDP-diacylglycerol in the
pharmacologic effect of different antidepressants and
raise the possibility that brain phospholipids could be
a target for the therapeutic action of the
antidepressant drugs.
154. INFLUENCE OF SHAKING ON THE
SPRAY WEIGHT OF NASAL SPRAY PUMPS
Lei Diao, Richard Dalby
Morning; Poster Presentation; MSTF Atrium
153. ACUTE SIGNALING EFFECTS OF
ANTIDEPRESSANT AGENTS IN
CULTURED PC12 CELLS
Marwa Aboukhatwa, Ashiwel Undie
Morning; Poster Presentation; MSTF Atrium
We investigated the influence of shaking on the spray
weight for five commercial OTC nasal spray pump
products representing a range of formulation types.
RITE AID (R), Nostrilla (N), Afrin (Af), Ayr and
Zicam (Z) nasal sprays were evaluated. A Pump
Actuation and Weigh Station (PAWS) was used
actuate and determine the spray weight of each brand
(n=3) based on the first 60 sprays following 10
priming sprays. Spray weight vs. spray number
profiles were compared to matched products shaken
manually. Photos of formulations in clear glass
containing the original formulation were obtained
before and immediately after shaking. R and N
demonstrated a significant (p<0.05) 24% and 16%
decrease, respectively, in mean spray weight after
shaking. The more viscous Af exhibited a gradually
declining profile with an average decrease of 8%
(p<0.05) after shaking. Shaking had little effect on
the spray weight of Ay and Z. The photos suggested
that non-viscous R and N formulations generated
large numbers of bubbles which may be drawn into
the dip tube to reduce subsequent spray weights. In
contrast, the moderately viscous Af generated many
smaller bubbles trapped in the formulation for
protracted periods. This might account for the less
dramatic but gradual decrease in spray weight over
Background: Depression is serious mood disorder
that affects millions of people all over the world. The
pathophysiology of this illness and its response to the
various treatments is not fully understood. A well
known mechanism of action for the antidepressant
drugs is to inhibit the synaptic reuptake of
monoamines such as serotonin, noradrenaline and/or
dopamine. Recently, it has been shown that brain
phospholipid metabolism may be involved in the
pathophysiology of mood disorders and the concept
that phopholipid synthesis enhancers could be
effective antidepressant drugs. In order to investigate
whether the classic antidepressant drugs have an
effect on brain phospholipid metabolism away from
the well known mechanism on the synaptic
monoamine levels, we used undifferentiated PC12 cell
culture to investigate the effects of antidepressant
drugs on CDP-diacylglycerol–a derivative of
diacylglycerol and a synthetic precursor of key
glycerophospholipids such as phosphatidylinositol
and phosphatidylcholine. Methods: We measured the
effects of three hours treatment with various
29th Annual Graduate Research Conference
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45
time. The most viscous Ayr and Z generated fewer
bubbles compared to Af. In general, shaking
decreased the spray weight of low viscosity
formulations to about 80 percent of the unshaken
spray weight. The effect of shaking on more viscous
formulations was less dramatic. This suggests that
nasal spray testing should document shaking prior to
in vitro spray evaluation, and ideally incorporate
shaking proven representative of likely modes of
patient use unless a product can be shown to be
unaffected by shaking.
156. ULTRAFILTRATION VS. IV DIURETICS
FOR PATIENTS HOSPITALIZED FOR
ACUTE DECOMPENSATED CONGESTIVE
HEART FAILURE (CHF): A PROSPECTIVE
RANDOMIZED CLINICAL TRIAL.
Rogers HL, Dowling TC, Marshall J, Gottlieb SS.
Morning; Poster Presentation; MSTF Atrium
Ultrafiltration (UF) is a dialytic method under
investigation for fluid removal in patients with CHF.
This prospective, randomized, double-blind study is
designed to evaluate the effect of ultrafiltration on
urine output and renal hemodynamics including
glomerular filtration rate (GFR) and renal plasma flow
(RPF) compared to a standard diuresis protocol.
Prospective GFR and RPF were measured using
Iothalamate (IOTH) and Para-amino Hippurate
(PAH) clearance, respectively. Patients received a
continuous IV infusion of renal biomarkers over 180
min before and after ultrafiltration or diuretic therapy
(48 hours later). Fluid removal interventions were
administered as necessary to achieve fluid removal
goals of (200-500ml/hr). Concentrations of IOTH
and PAH in plasma and urine samples were
determined using HPLC. Nineteen patients (13 males,
5 females) were enrolled with 10 randomized to
standard therapy and 9 to UF. Within the UF group,
the mean change in GFR and RPF following
treatment was +1.3±13.8ml/min (p=0.79) and
+37.6±86.8ml/min (p=0.23) respectively. Within the
standard therapy group, the mean change in GFR and
RPF following treatment was -3.6±11.5 ml/min
(p=0.35) and 16.1 ±42.0 ml/min (p=0.26)
respectively. In terms of urine output, there was a
trend towards greater urine output during diuretic
therapy 55±109ml/hr, (p=.09). The results of this
study indicate that UF and standard diuresis appear to
have similar effects on GFR, RPF and urinary output.
The greater magnitude of urinary output following
standard therapy was expected, however trends of
increased GFR, RPF and filtration fraction following
UF compared to standard diuresis requires further
evaluation.
155. INNERVATION, DISTRIBUTION AND
MOLECULAR IDENTITY OF THE
NECKLACE GLOMERULI
R Cockerham, T Leinders-Zufall, RR Reed, DL
Garbers, F Zufall and SD Munger
Morning; Poster Presentation; MSTF Atrium
Several subpopulations of neurons have been
suggested to innervate the “necklace” glomeruli
(NGs) of the caudal olfactory bulb, including (1) main
olfactory epithelium (MOE) neurons expressing the
phosphodiesterase isoform PDE2A and the orphan
receptor guanylyl cyclase GC-D; (2) MOE neurons
responsive to some volatile pheromones; (3) neurons
of the Septal Organ of Grueneberg. NGs are a poorly
defined subset of acetylcholinesterase (AChE)positive glomeruli in the caudal bulb. To test whether
the NGs receive input from MOE neurons expressing
GC-D and PDE2A, we generated Gucy2d (GC-D)
knockout mice containing an IRES-Mapt-lacZ
reporter construct. β-galactosidase-positive axons in
these mice innervate a subset of caudal glomeruli in
the main olfactory bulb. As indicated by reduced
tyrosine hydroxylase immunohistochemistry, afferent
activity to these glomeruli is reduced in Gucy2d -/mice. Glomeruli innervated by β-gal-positive neurons
are consistent in position and number with the NGs,
and this innervation pattern is nearly identical in
Gucy2d +/- and -/- mice. All β-gal-positive glomeruli
are also PDE2A-positive, confirming PDE2A as a
marker exclusively for GC-D neurons and NGs.
Together, these findings indicate that NGs are
exclusively innervated by GC-D/PDE2A-expressing
neurons.
29th Annual Graduate Research Conference
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46
157. LOCALIZATION AND KINETICS OF
ACTIN DYNAMICS IN DENDRITIC SPINES
CONTROLLED BY PROTEIN
INTERACTIONS AT THE POSTSYNAPTIC
DENSITY
Nicholas A Frost, Xi Zhan, Thomas A Blanpied
Morning; Poster Presentation; MSTF Atrium
158. THE EFFECT OF ANTIPSYCHOTIC
DRUG TREATMENT ON REWARD
LEARNING AS ASSESSED BY AUTOSHAPED
BEHAVIOR
CL Stamps, GI Elmer
Morning; Poster Presentation; MSTF Atrium
Positive symptoms of schizophrenia include such
things as hallucinations and delusions, while the
negative symptoms include deficits in behavior such
as lack of social interest and motivation. The
cognitive deficits present in a number of ways
including decreased IQ, memory impairment, and
disorganized thoughts. The positive symptoms may
be effectively treated with antipsychotics, however
there is no therapy currently available that effectively
treats negative symptoms or disruptions in cognition.
Typical and atypical antipsychotics have antagonist
properties (to varying degrees) at the dopamine D2
receptors. Unfortunately, this interaction also leads to
negative consequences, including a dampening of
reward processing. An impairment of reward learning
may play a significant role in the cognitive deficits
seen in schizophrenia. The purpose of this study was
to determine the effect of anitpsychotic drug
administration on a simple model of Pavlovian
learning. We used an autoshaping procedure to assay
the effect of haloperidol (HAL; 0.003; 0.01, 0.03, and
0.1 mg/ml) on reward processing. It was found that
HAL attenuated the ability to discern positive versus
neutral cues in a dose dependent manner. This effect
was significant at 0.03 mg/ml, and a dose of 0.01
mg/ml completely eliminated responding. These
results indicate that reward processing is disrupted in
the presence of HAL. After the initial autoshape
training the stimulus lights were reversed. It was
found that, surprisingly, HAL treatment did not
disrupt reward learning during the reversal. This has
implications for the treatment of schizophrenia and
the analysis of reward processing data in people with
schizophrenia, since the medication itself may have
effects on reward learning.
In the brain, communication between neurons takes
place at points of connection called synapses.
Synapses are inherently plastic, and can undergo rapid
changes in morphology and molecular content. Such
synaptic plasticity is required for developmentally
regulated changes in behavior and cognition, and
underlies learning and memory throughout the
lifespan. We are investigating the cellular mechanisms
that dynamically control synapse structure and
function. Most excitatory synapses take place on
small, bulbous protrusions from the neuronal
dendrite called dendritic spines. A broad variety of
neuropsychiatric and neurological diseases are
accompanied by patterns of spine disruption. For
instance, one of the earliest changes in Alzheimer’s
disease brain pathology is a loss of dendritic spines,
which precedes the more well-known neuronal death
that occurs in advanced stages. The onset of dementia
in fact correlates more strongly with spine loss than
cell death. In addition, the major hereditary mental
retardation syndromes, Fragile X and Down’s, are
accompanied by changes in spine morphology, in
particular a decrease in mature spines and an increase
in elongated protrusions that resemble spine
precursors called filopodia. Schizophrenia, on the
other hand, is accompanied by a reduced spine
density in neurons of the prefrontal cortex. Thus,
abnormal spine growth and structure accompanies,
and likely underlies, diverse psychiatric pathology.
The major determinant of spine morphology is the
intracellular actin cytoskeleton. Spines are rich in
actin, and polymerization and depolymerization of
branching actin filaments in the spine has recently
been shown to be a rapidly regulated process. This
actin turnover provides the fundamental mechanism
of spine morphological change.
159. TN AS A SELECTIVE ANTAGNIST OF
THE HUMAN CONSTITUTIVE
ANDROSTANE RECEPTOR
29th Annual Graduate Research Conference
Friday, April 20, 2007
47
Linhao Li, Tao Chen, and Hongbing Wang
Morning; Poster Presentation; MSTF Atrium
medical records at the University of Maryland Medical
Center (UMMC) contained indicators notifying
healthcare workers of previous MRSA colonization or
infection. These indicators are computerized alerts,
used to direct contact isolation. It is unknown
whether an MRSA indicator influences antibiotic
prescribing behavior for patients with suspected
bacteremia and improves therapy in those who have
MRSA bacteremia. We aimed to assess the association
between MRSA indicator status and choice of empiric
antibiotic therapy among patients with suspected
bacteremia. This retrospective cohort study analyzed
all adult patients admitted to UMMC between 2001
and 2005, who had a blood culture drawn for
suspected bacteremia and received any empiric
therapy during the period 24 hours before and 24
hours after the culture was drawn. Appropriate
empiric therapy for MRSA was defined as receipt of
vancomycin during the above time period. Among
25,571 admissions, 2,088 (8.2%) had a known history
of MRSA before the culture was drawn. Patients with
known MRSA history were twice as likely to receive
appropriate empiric therapy for MRSA compared to
those without known MRSA history (relative risk
[RR]=2.43, 95% confidence interval [CI]: 2.28, 2.59).
Of the 288 admissions in whom the blood cultures
were positive for MRSA, patients with a previous
history of MRSA were 11% more likely to receive
appropriate MRSA empiric therapy compared to
those without MRSA history; but this was not
statistically significant (RR=1.11, 95% CI: 0.89, 1.42).
Thus, maintenance of infection control data within
electronic medical records may improve prescribing
of appropriate empiric antibiotic therapy for MRSA
bacteremia.
As a xenobiotic sensor, constitutive androstane
receptor (CAR) regulates the induction of multiple
drug metabolizing enzymes and transporters.
However, CAR is constitutively activated and
insensitive to chemical activations in all immortalized
cell lines. This characteristic of CAR has greatly
hindered its utilization as a predictor of metabolisebased drug-drug interactions. In this study, we
identified that TN, a peripheral benzodiazepine
receptor ligand, could selectively inhibit the
constitutive activation of human CAR in vitro. In cellbased reporter assay utilizing HepG2 cells, TN could
efficiently inhibit the constitutive activity of hCAR by
90 % at the concentration of 10 uM treatment. In
contrast, TN has demonstrated potent activation of
human pregnane X receptor (hPXR) indicating it may
have a complex effect on the PXR and CAR shared
target genes. Intriguingly, we also noticed that this
dose-dependent antagonistic effect of TN on hCAR
was only reversed by direct hCAR activator (such as
CITCO) but not by indirect activators (such as PB),
suggesting that TN bounds to hCAR antagonistically.
Currently, the effects of TN on multiple CAR target
genes are under investigation using human primary
hepatocytes and transfected cell lines. We believe that
identification of selective hCAR deactivator would
provide useful tools for elucidating the distinct role of
hCAR in drug metabolism and transportation.
160. ELECTRONIC MEDICAL RECORD
INDICATORS OF PREVIOUS
COLONIZATION OR INFECTION WITH
METHICILLIN-RESISTANT
STAPHYLOCOCCUS AUREUS (MRSA) AND
EMPIRIC THERAPY FOR SUSPECTED
BACTEREMIA
ML Schweizer, JP Furuno, AD Harris, JC McGregor,
K Thom, HC Standiford, JN Hebden, EN
Perencevich
Morning; Poster Presentation; MSTF Atrium
161. DEMENTIA AND SHORT TERM
RECOVERY FROM HIP FRACTURE
Hannah R.Day,
Ann L. Gruber-Baldini, Jay
Magaziner
Morning; Poster Presentation; MSTF Atrium
Although people with dementia do poorly after hip
fracture, little is known about how the severity of
dementia affects functional recovery. The current
study examined 188 people with dementia (diagnosis
Recurrence of MRSA infection is common among
previously-infected patients. Since 1996, electronic
29th Annual Graduate Research Conference
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48
from chart or proxy report) drawn from a larger study
of 674 hip fracture patients in the Baltimore Hip
Studies. Two-month outcomes included 15 physical
Activities of Daily Living (ADL), 7 Instrumental
ADLs (IADL), and ability to walk 10 feet. Severity of
dementia was estimated by proxy rating of prefracture ability to complete Mini-Mental State
Examination (MMSE) items (n=162 with severity
information). Among hip fracture patients with
dementia, 20.4% had pre-fracture MMSE 24+, 42.0%
MMSE 17-23, 16.7% MMSE 11-16, and 21.0%
MMSE ≤ 10. Results of ANOVAs, controlling for
pre-fracture functional status, found no significant
differences in ADL and IADL recovery by dementia
severity. Significant (p<.05) differences in walking
were found by level of dementia severity, such that
57.7% of those with a pre-fracture MMSE ≤ 10 were
able to walk, compared to 71.4% MMSE 11-16, 86%
MMSE 17-23, and 87.0% MMSE 24+. However,
only 5.2% could walk without assistance at 2 months.
Although hip fracture patients with dementia differ in
pre-fracture levels of functioning, this study found
that recovery on ADLS and IADLs did not differ by
severity of dementia. A majority of hip fracture
patients with dementia are able to walk with
assistance by two months, but those with a MMSE ≤
10 are less likely to recover walking ability.
beneficiaries with diabetes varies by decile of total
medical spending (a proxy of disease burden), and to
identify factors that statistically explain the observed
differences.
163. THE ASSOCIATION BETWEEN
URINARY INCONTINENCE ANS FALLS
AMONG THE ELDERLY LIVING IN THE
COMMUNITY: CROSS-SECTIONAL STUDY
USING THE MEDICARE CURRENT
BENEFICIARY SURVEY
Masayo Sato, Ilene H. Zuckerman, Bruce C. Stuart
Morning; Poster Presentation; MSTF Atrium
Objective: Our objective was to assess whether
urinary incontinence is associated with falls among
the elderly living in the community. Methods: The
2002 Medicare Current Beneficiary Survey Cost and
Use files were used to identify beneficiaries aged 65
years and older living in the community (N=9,080).
The key predictor was self-reported urinary
incontinence and the outcome was a fall. Potential
confounders considered were age, sex, race, body
mass index, smoking status, health status, physical
functioning, comorbid conditions, cognition,
depression, and medication use. All information was
obtained from the survey questionnaire. Multiple
logistic regression was used for the analyses to
examine
the
relationship
between
urinary
incontinence and falls. Results: The prevalence of
urinary incontinence was 23.0% (17.2% in females;
5.8% in males). Thirty-eight percent of subjects with
urinary incontinence reported that they lost urine
control more than once a week in the past year. After
adjusting for potential confounders, dichotomized
urinary incontinence was significantly related to falls
(OR=1.25; 95% CI, 1.10–1.43). When urinary
incontinence was categorized by the frequency of
episodes into six categories, subjects with episodes of
more than once a week were more likely to report
falls compared to subjects with no urinary
incontinence (OR=1.28; 95% CI, 1.05–1.56).
Conclusion: Urinary incontinence was independently
associated with falls in a representative sample of the
community-dwelling aged Medicare population. In
particular, frequent episodes of urinary incontinence
162. HOW BURDEN OF ILLNESS AFFECTS
TREATMENTS FOR DIABETES IN OLDER
ADULTS
Bruce Stuart, Thomas Shaffer, Linda Simoni-Wastila,
Ilene Zuckerman, Charlene Quinn
Morning; Poster Presentation; MSTF Atrium
Recent guidelines for treating older patients with
diabetes mellitus places less stress on glycemic control
and emphasize the potential harm that may arise from
adherence to strict regimens with antidiabetic
medications. However, there are few empirical
benchmarks against which clinicians can compare
their prescribing of antidiabetic medications for
patients who have diabetes and varying levels of
comorbidity. This study was designed to provide
national estimates showing how the intensity of
antidiabetic medication regimens for Medicare
29th Annual Graduate Research Conference
Friday, April 20, 2007
49
appear to explain the relationship with falls. Better
management of urinary incontinence may prevent the
occurrence of falls and subsequent falls-related
negative consequences.
relationship between parental impressions of school
structures and parental academic support, and
explores moderating variables such as discrimination.
164. EXPLORING THE RELATIONSHIP
BETWEEN PARENTAL IMPRESSIONS OF
SCHOOL STRUCTURES AND PARENTAL
ACADEMIC SUPPORT: A COMPARATIVE
STUDY OF LATINO AND CAUCASIAN
EXPERIENCES
Ann Buckwalter
Morning; Poster Presentation; MSTF Atrium
Latino parents have consistently experienced distrust,
discrimination and oppression from the U.S. public
education system via school structures (Ogbu, 1987).
However, despite these structural barriers and the
consequent lack of visible Latino parental
participation in schools, there is a wealth of literature
indicating that Latino parents place great value on
their children’s education. Likewise, Latino parents in
general report providing much academic support for
their children (Drummond; Stipek, 2004).
An
entrenched racism framework explains this
disconnect, proposing that although Latino parents
desire to actively participate in their children’s
schooling, discriminatory barriers interfere, and the
'absence’ of Latino parents in the schools
demonstrates resistance, rather than a sign of
disinterest (Olivos, 2004).
Critical race theory
supports this by explaining racism and its cumulative
impact on individuals and groups (Solorzano &
Yosso, 2001). The present study quantitatively
examines the relationship between parental
impressions of school structures and parental
academic support, and specifically compares Latino
and Caucasian experiences.
Although several
qualitative studies provide explanations regarding the
gap that exists between Latino parents desiring to
provide academic support for their children and
actually providing support in the manner defined by
schools (Quiocho & Daoud, 2006), there is a
lack of studies that quantitatively addresses this issue.
Using data on Latino and Caucasian parents collected
by the Pew Hispanic Center, this study examines the
29th Annual Graduate Research Conference
Friday, April 20, 2007
50
PRESENTER
INDEX
29th Annual Graduate Research Conference
Friday, April 20, 2007
51
Aboukhatwa, Marwa; Poster, Morning, MSTF Atrium: 153
Acharya, Chayan; Poster, Morning, MSTF Atrium: 151
Acquavita, Shauna; Oral, Afternoon, MSTF 156/158: 35
Anisimov, Victor; Poster, Morning, MSTF Atrium: 133
Apostolou, Andria; Oral, Afternoon, HSFII 241: 21
Bae, Mihyun; Poster, Morning, MSTF Atrium: 140
Baksh, Charlene; Poster, Morning, MSTF Atrium: 103
Ballar, Petek; Oral, Afternoon, HSFII S600: 13
Barbier, Elisabeth; Poster, Morning, MSTF Atrium: 150
Bernstein, Jade; Oral, Morning, HSFII 241: 1
Bissonette, Greg; Poster, Afternoon, MSTF Atrium: 126
Borzok, Maegen; Poster, Morning, MSTF Atrium: 134
Brady, Rebecca; Poster, Afternoon, MSTF Atrium: 104
Brown, Marishka; Poster, Morning, MSTF Atrium: 152
Bruno, Robert; Poster, Morning, MSTF Atrium: 149
Buckwalter, Ann; Poster, Morning, MSTF Atrium: 164
Busby, Benjamin; Poster, Afternoon, MSTF Atrium: 121
Cantor, Stuart; Oral, Afternoon, HSFII 241: 23
Castellanos-Brown, Karen; Poster, Afternoon, MSTF Atrium: 132
Charpentier, Thomas; Oral, Afternoon, HSFII 241: 25
Cockerham, Renee; Poster, Morning, MSTF Atrium: 155
Coles, Lisa; Poster, Morning, MSTF Atrium: 137
Day, Hannah; Poster, Morning, MSTF Atrium: 161
Dean, Shannon; Poster, Afternoon, MSTF Atrium: 120
Desai, Bhavik; Oral, Morning, HSFII 241: 2
Deshpande, Gaurav; Poster, Afternoon, MSTF Atrium: 130
Diao, Lei; Poster, Morning, MSTF Atrium: 154
Dilgen, Jonathan; Poster, Afternoon, MSTF Atrium: 117
Dosanjh, Nuvjeevan; Oral, Afternoon, HSFII S600: 19
Doyle, Otima; Oral, Afternoon, MSTF 156/158: 36
Fakunmoju, Sunday; Oral, Morning, MSTF 156/158: 32
Fang, Yueh-Yen; Oral, Morning, MSTF 156/158: 27
Fedorowski, Jennifer; Poster, Afternoon, MSTF Atrium: 114
Feng, Bo; Poster, Afternoon, MSTF Atrium: 122
Fisher, Scott; Poster, Afternoon, MSTF Atrium: 125
Fitzgerald, Megan; Poster, Morning, MSTF Atrium: 141
Frost, Nicholas; Poster, Morning, MSTF Atrium: 157
Gibbons, Maya; Oral, Afternoon, MSTF 156/158: 37
Guvench, Olgun; Poster, Afternoon, MSTF Atrium: 106
Harro, Janette; Oral, Afternoon, HSFII 241: 20
Hawkins, Arie; Oral, Morning, HSFII S600: 8
Hayward, Anna; Oral, Morning, MSTF 156/158: 30
Hebbeler, Andrew; Oral, Morning, HSFII 241: 3
Jin, Feiyan; Poster, Afternoon, MSTF Atrium: 109
Kamath, Ganesh; Poster, Afternoon, MSTF Atrium: 111
Kaur, Ajinder; Poster, Afternoon, MSTF Atrium: 118
29th Annual Graduate Research Conference
Friday, April 20, 2007
52
Kerr, Justin; Oral, Morning, HSFII S600: 12
Khandelwal, Aakanksha; Poster, Morning, MSTF Atrium: 144
Kundoor, Vipra; Poster, Morning, MSTF Atrium: 138
Lawpoolsri, Saranath; Oral, Morning, MSTF 156/158: 28
Lee, Seung Jae; Poster, Afternoon, MSTF Atrium: 107
Li, Xiaoling; Oral, Afternoon, HSFII S600: 15
Li, Linhao; Poster, Morning, MSTF Atrium: 159
Lin, Shu-fei; Poster, Afternoon, MSTF Atrium: 102
Lopes, Pedro; Poster, Afternoon, MSTF Atrium: 123
Luncsford, Paz; Poster, Afternoon, MSTF Atrium: 101
Martins, Gabriela; Poster, Morning, MSTF Atrium: 139
McCranor, Bryan; Poster, Afternoon, MSTF Atrium: 108
Michaelson, Luke; Poster, Morning, MSTF Atrium: 142
Molitoris, Kristin; Poster, Afternoon, MSTF Atrium: 105
Moolchandani, Vikas; Poster, Afternoon, MSTF Atrium: 119
Morgan, Michael; Poster, Morning, MSTF Atrium: 135
Natarajan, Karthika; Oral, Afternoon, HSFII S600: 16
Paik, Sehmi; Poster, Morning, MSTF Atrium: 143
Park, Juyoung; Oral, Morning, MSTF 156/158: 29
Parker, Karen; Oral, Morning, MSTF 156/158: 31
Puttabyatappa, Muraly; Oral, Afternoon, HSFII S600: 14
Qi, Bing-Bing; Oral, Afternoon, MSTF 156/158: 33
Rajagopal, Deepa; Poster, Afternoon, MSTF Atrium: 116
Reader, Jocelyn; Oral, Morning, HSFII 241: 4
Roberts, Zachary; Oral, Morning, HSFII 241: 5
Robertson, Brian; Oral, Morning, HSFII S600: 7
Roche, Joseph; Oral, Afternoon, HSFII S600: 18
Rogers, Hobart; Poster, Morning, MSTF Atrium: 156
Samant, Navendu; Poster, Afternoon, MSTF Atrium: 131
Sato, Masayo; Poster, Morning, MSTF Atrium: 163
Schayowitz, Adam; Oral, Morning, HSFII S600: 10
Schwarz, Jaclyn; Oral, Morning, HSFII S600: 11
Schweizer, Marin; Poster, Morning, MSTF Atrium: 160
Shaffer, Thomas; Poster, Afternoon, MSTF Atrium: 129
Shaffer, Thomas; Poster, Morning, MSTF Atrium: 162
Shoaibi, Azadeh; Poster, Afternoon, MSTF Atrium: 128
Smith, Kelsy; Poster, Morning, MSTF Atrium: 148
Song, Wei; Oral, Morning, HSFII 241: 6
Souther, Vickie; Oral, Afternoon, MSTF 156/158: 38
Stamps, Carey; Poster, Morning, MSTF Atrium: 158
Strauman, Maura; Oral, Afternoon, HSFII 241: 22
Sun, Peng; Oral, Afternoon, HSFII 241: 26
Tchantchou, Flaubert; Poster, Afternoon, MSTF Atrium: 124
Toreson, Kathy; Poster, Afternoon, MSTF Atrium: 113
Udayakumar, Deva; Poster, Afternoon, MSTF Atrium: 112
Upreti, Vijay; Oral, Afternoon, HSFII 241: 24
29th Annual Graduate Research Conference
Friday, April 20, 2007
53
Vanommeslaeghe, Kenno; Poster, Morning, MSTF Atrium: 145
Wang, Ying; Oral, Morning, HSFII S600: 9
Wei, Hua; Poster, Afternoon, MSTF Atrium: 115
Weiss, Michele; Poster, Afternoon, MSTF Atrium: 110
Wilson, Melinda; Poster, Afternoon, MSTF Atrium: 127
Wooten, Nikki; Oral, Afternoon, MSTF 156/158: 34
Wright, Christopher; Oral, Afternoon, HSFII S600: 17
Wright, Nate; Poster, Morning, MSTF Atrium: 147
Wu, Yanjue; Poster, Morning, MSTF Atrium: 146
Xu, Yanan; Poster, Morning, MSTF Atrium: 136
29th Annual Graduate Research Conference
Friday, April 20, 2007
54
Notes:
29th Annual Graduate Research Conference
Friday, April 20, 2007
55
Notes:
29th Annual Graduate Research Conference
Friday, April 20, 2007
56