CLINICAL CHEMISTRY
Units of Measurements
o
Units define physical quantities and dimension such as
length, mass, time, or volume. It provide a proper
interpretation of laboratory result or data internationally.
Analytical Reagent Grade - Contains chemical that have
high purity; commonly used in foods and drugs. And
recommended to utilized in analytical laboratory.
Ultrapure Grade - Contains high quality of chemical; the
levels of impurities are unknown. Usually pure enough
for educational applications but not applicable to used in
foods and drugs.
Chemically Pure Grade - Contains pure chemical; do not
have standard limitation but it also do not meet the
laboratory requirements. Usually pure enough for
educational applications but not applicable to used in
foods and drugs.
USP & National Formulary Grades - Contains pure
chemical; commonly used for manufacturing drugs. And
it also used in producing medical devices, and dietary
supplements. Moreover, it should be reviewed prior to
beginning to ensure the grade is appropriate or
considered equivalent grades.
Commercial Grades - Contains impurities; commonly
used in technical and industrial purposes. Therefore, it is
not highly recommended for foods and drugs utilization.
Laboratory supplies commonly used in Clinical
Chemistry:
o
o
o
o
Volumetric flask is calibrated to contain a
precise volume at a certain temperature.
Volumetric flasks are used for precise dilutions
and preparation of standard solutions.
Erlenmeyer flasks and Griffin beakers are
designed to hold different volumes rather than
one exact amount. Because Erlenmeyer flasks
and Griffin beakers are often used in reagent
preparation, flask size, chemical inertness, and
thermal stability should be considered.
Graduated cylinders has calibration marks along
its length and is used to measure volumes of
liquids.
Pipettes are glass or plastic equipment used to
transfer liquids. Usually used for volumes of 20
o
o
o
mL or less; larger volumes are usually transferred
or dispensed using automated pipetting devices.
Syringes are sometimes used for transfer of
small volumes (< 500 μL) in blood gas analysis
or in separation techniques such as
chromatography or electrophoresis.
Analytic balances are required for the
preparation of any primary standard.
Electronic balances are single-pan balances that
use an electromagnetic force to counterbalance
the weighed sample's mass. Advantage of a fast
response time (< 10 seconds).
Centrifuges are generally used to separate
serum or plasma from the blood cells as the
blood samples are being processed; to separate
a supernatant from a precipitate during an
analytic reaction; to separate two immiscible
liquids, such as a lipid-laden sample; or to
expel air.
Analytical Instruments
®Spectrophotometry - each compound absorbs or
transmits light over a certain range of wavelength.
Measurement of the light transmitted by a solution to
determine concentration of the light-absorbing
substance in the solution.
COMPONENTS:
a.
Monochromator - produces light of a specific
wavelength from a light source.
b.
Sample Cell or Cuvette - used to hold colored
solutions for readings.
c.
Photodetector - a system that converts the
radiant energy into electrical energy and generate it into
the display or galvanometer reading.
Photometry - it is the measurement of the luminous
intensity of light or the amount of luminous light falling
on a surface from such a source. Photometric measures
the light intensity without considering the wavelength.
®Electrochemistry - the relationship between the
generation of electricity and associated chemical
changes in a reaction and vice versa. Chemical reaction
is used to produce an electric current.
®Electrophoresis - the migration and separation of
charged particles (ions) under the influence of an electric
field.
®Chromatography - molecules in mixture applied onto
the surface or into the solid. The mixture of materials to
be separated is percolated through a column or sheet of
some suitable absorbent (an ion-exchange material); the
substances least absorbed are least retarded and
emerge earliest; those more strongly absorbed emerge
later
®Osmometry - Based on the colligative property of
freezing point depression.
®Refractometry - The refraction based on the speed of
the light that passes in the different mediums.
®Densitometry - the measurement of light absorption at
a single point.
®Nephelometry - the measurement of the amount of
light scattered by a particulate solution. Technique for
estimation of the number and size of particles in a
suspension.
®Scintillation counting - An instrument used for the
detection of radioactivity; the radiation is absorbed by a
scintillator that results in minute flashes of light that are
detected by a photocathode.
®Automation - Whenever the legal moves of a formal
system are fully determined by algorithms, then that
system can be automated.
®Immunochemical Techniques - Measures the
utilization of high specific affinity of antibody to an
antigen.
•••••••••••••••••
Pathway In Glucose Metabolism
Glycolysis - the breakdown of glucose to form
pyruvate and lactate for production of energy.
Gluconeogenesis - the formation of glucose 6
phosphatase from non-carbohydrate sources
such as as fats or fatty acid and amino acid for
energy production.
Glycogenolysis - is the conversion of glycogen to
form glucose.
Glycogenesis - is the process of storing the excess
glucose in the glycogen.
Endocrine - a system in organ that doesn't have ducts
yet contain blood vessels in which where secretion
happens. Insulin, Glucagon, Somatostatin and Gastrin
are secreted via this type of system.
Exocrine - a system in organ that contain ducts,
therefore the secretion is on the ducts. Enzymes for
digestion process (pancreatic amylase) are secreted via
this type of system.
Hormones That Allows Glucose Metabolism In Our
Body:
Hormonal Regulation
 Insulin
- secreted by beta cells in islets of
langerhans.
- released when there is an increase level
of glucose the blood circulation.
- considered as hypoglycemic agent
because it promotes glycogenesis,
glycolysis, and decrease glycogenolysis.
 Glucagon
- secreted by alpha cells in islets of
langerhans.
- triggers the release of stored glucose
from the liver.
- considered as hyperglycemic agent
because it promotes glycogenolysis.
OTHER HYPERGLYCEMIC HORMONES
 Somatostation secreted by delta cells.
- inhibits the action of insulin and
glucagon.
 Cortisol
- secreted by the cells of zona fasiculata of
adrenal cortex.
- considered as hyperglycemic agent
because it promotes gluconeogenesis
and lipolysis.
 Catecholamines
- secreted by chromaffin cells of adrenal
medulla.
- considered as hyperglycemic agent
because it promotes glycogenolysis and
lipolysis.
 Growth Hormone (GH)/ Somatotroph secreted by anterior pituitary gland.
- responsible for the growth of individual.
-
considered as hyperglycemic agent
because it promotes glycogenolysis
 Thyroid Hormones secreted by thyroid
gland.
- Two types: triidothyronine and
tetraidothyronine/thyroxine.
- considered as hyperglycemic agent
because it promotes glycogenolysis,
gluconeogenesis, and intestinal
absorption of glucose
 ACTH (Adrenocorticotrophic Hormone) secreted by anterior pituitary gland.
- stimulates the release of cortisol from
the adrenal cortex.
- considered as hyperglycemic agent
because it promotes glycogenolysis and
gluconeogenesis. Disorders of Glucose
Metabolism
Hypoglycemic disorders
 Warning signs and symptoms are related to CNS.
 Impaired glucose fasting (50 mg/dL - 55mg/dL)
meaning there is observable of symptoms of
glycemia.
 Diagnostic Hypoglycemia (Less than 1/ =
50mg/dL.
 Whipple's triad - is a collection of three signs
(called Whipple's criteria) that suggests that a
patient's symptoms result from hypoglycemia
that may indicate insulin.
- low blood glucose concentration
- typical symptoms (mental disturbances)
- alleviated glucose administration (upon
giving him/ her the glucose load it is
corrected by signs and symptoms.
Symptoms of Hypoglycemia (CNS)
••• Neurogenic - tremors, palpitations, anxiety, and
disphoresis (excessive sweating).
••• Neuroglycopenic - dizzines, tingling, blurred vision,
confusion, and behavioral changes.
Classification of Hypoglycemia
 Drug Administration - Insulin; Alcohol
 Critical Illness - renal failure, hepatic failure,
malnutrition, sepsis
 Hormonal deficiency - epinephrine, glucagon,
cortisol, and GH
 Endogenous Hyperinsulinism - pancreatic beta
cells disorders
 Autoimmune Hypoglycemia - insulin antibodies
 Non-beta cell tumors: Pheochromocytoma results in the irregular and excessive release of
these hormones.
 Hepatoma (Tumor in liver)
- Leukemia (cancer in bone marrow)
- Lymphoma (tumor in lymphoid organ)
 Alimentary (Reactive) Hypoglycemia:
Postgastric surgery - refers to a person
undergone surgical procedure and affects the
function of its digestive system.
 Idiopathic (Functional)
- Postprandial Hypoglycemia
Hyperglycemic disorder
 Increase in blood glucose levels.
 Causes: stress, dehydration or pregnancy
hormonal imbalance, pancreatectomy, insulin
deficiency or abnormal insulin receptor.
 FBS level: greater than 1/ = 126mg/dL Laboratory
Findings of Hyperglycemia
¶ Increase glucose in plasma and urine
¶ Increase urine specific gravity
¶ Ketones in serum and urine (acetoacetate,
βhydroxybutyric acid, acetone)
¶ Decrease blood and urine pH (acidosis)
¶ Electrolyte Imbalance (Na, K, HCO3)
Diabetes mellitus
o
a group metabolic disorders characterized by
hyperglycemia. o FBS level: greater than 1/
= 126mg/dL o 8 to 6 hours fasting o Glucosuria
occurs when plasma glucose levels
exceeds 180mg/dL
o
o
Ketosis develop in DM o Presence of ketone
bodies is a frequent finding in individuals with
severe, uncontrolled diabetes.
In severe DM, the ratio of Betahydroxybutyrate to acetoacetate is 6:1.
1. Type 1 Diabetes mellitus
-
-
autoimmune or idiopathic beta cells destruction
leading to absolute insulin deficiency/
insulinopenia (decrease of insulin)
Idiopathic means it has no known etiology; it is
strongly inherited.
commonly occurs in childhood and adolescence.
-
-
-
insulin resistance with progressive insulin
deficiency.
associated with strong genetic predisposition but
not related to an autoimmune disease.
-If left untreated= non ketotic hyperosmolar
coma (glucose is greater than/= 500mg/dL)
Severe Symptoms of Type 2 Dm
∆ Severe dehydration
∆ Electrolyte imbalance ∆ Risk
factors: obesity, hypertension,
gestational DM, and impaired glucose
metabolism.
3. Gestational Diabetes Mellitus
-
-
-
-
as the placenta grows, it makes more of the
hormones. If it can't make enough to overcome
the effects of the placenta's hormones, you can
develop gestational diabetes.
screening should be performed between 24-28
weeks of pregnancy (1hour Glucose Challenge
Test -50g)
Plasma glucose of 140mg/dL or greater -FULL 3hours OGTT with 100g glucose - OGTT results:
1. FBS: greater/ = 95mg/dL
2. 1-hour: greater/ = 180mg/dL
3. 2-hours: greater/ = 155mg/dL
4. 3-hours: greater/ = 140mg/dL
glucose intolerance during pregnancy that
disappears post-partum but may convert to type
2 DM in 30%-40% of cases within 10 years due to
metabolic and hormonal changes.
GDM converts to DM within 10 years 30-90% of
cases.
Diagnosis of Type 2 Diabetes mellitus and Pre-diabetes
•
2. Type 2 Diabetes mellitus
-
diagnosed if 2 plasma values or more of the
above glucose levels are exceeded.
Infants: increase risk of Respiratory Distress
Syndrome (RDS), Hypocalcemia,
Hyperbilirubinemia.
after giving birth: evaluation 6-12 weeks
postpartum
ADA Recommendations
- An adults >45 years should be screened
every 3 years
- Testing should be carried out an earlier
age or more frequently in individuals
who are overweight (25-29.9kg/m²) or
obese (> /= 30kg/m²) and have additional
risk factors.
- If the RPG is >/= 160mg/dL, a fasting
plasma glucose, HbA1c, or 2 hour OGTT
should be performed.
Importart Consideration For 2-hour OGTT
•
•
•
•
Should be ambulatory and on a normal to high
carbohydrate (150 g / day ) intake for 3 days
before the test.
Fasting for 8 -14 hours
Refrain from exercise, eating, drinking and
smoking just before and during the test.
Standard dose of glucose solution is 75g (non
pregnant) or 1.75g/kg
Measures of Glycemic Control
Glycosylated Hemoglobin/Hb A1c
 More commonly used to assess glycemic control
among diagnosed patients.
 Provides an index of average blood glucose
levels over the past 2-4 months (Average:3)
 Unreliable in patients with hemolytic disorders (
ex. Hemoglobinopathies and hemolytic anemias)
 Determine on a hemolysate prepared from
EDTA whole blood using immunoassay,
electrophoresis or chromatographic methods
Fructosamine
 Used to assess short term ( 3-6 weeks) glycemic
control.
 Usedful in patients for whom HbA1c assays are
inaccurate.
 Has the advantage of using serum samples but is
affected by alterations in serum protein levels
and should not be performed if the serum
albumin level is </=3.0g/dL.
c) Condensation
o-toluidine reacts with glucose to form a glucosamine
that has an intense green color. The color is then
measured spectrophotometrically to estimate the
glucose concentration.
Chemical Reaction
Glucose + o-toluidine  schiff's base (green color)
Whole Blood Glucose
 Must commonly analyzed using POCT devices at
home (self-monitoring) or at the patient's
bedside; 3-4 times per day for type 1 DM
patients according to ADA guidelines.
Methods of Glucose Measurement
[Chemical Methods]
a) Copper Reduction
Used to detect glucose in urine. The test is based on
the principle that substances that reduce copper
sulfate to cuprous oxide in the presence of alkali and
heat will produce a color change, which confirms the
presence of glucose.
[Enzymatic methods]
A. Glucose oxidase
A highly specific method for measurement of
glucose in serum or plasma by reaction with
glucose oxidase, in which gluconic acid and
hydrogen peroxide are formed.
Detection methods:
•°• Peroxidase-coupled / Trinder reaction - subject to
many interference (ex. strong oxidizing agents ascorbic
and bilirubin, and ionic acid).
•°• Polarographic - measurement of the degree O2
consumption using 02 sensing ( Clark) electrode;
requires addition of molybdate and iodide or catalase
or ethanol.
Methods
Chemical Reaction
Chemical Reaction
Folin-Wu
Cu+ + Phosphomolybdic acid 
Phosphomolybdenum blue
B- D- Glucose +O2 + H2O -----glucose oxidase 
gluconic acid + H2 O2
Nelson-Somogyi
Cu+ + Arsenomolybdic acid 
Arsenomolybdenum blue
Neocuproine
Cu+ + Neocuproine  Cu
Neocuproine complex (
yelloworange)
b) Ferric Reduction
Based on the principle that substances, which have
reduction potential, react with potassium
ferricyanide (Fe3+) to form potassium ferrocyanide
(Fe2+).
Chemical Reaction
Ferricyanide  Ferrocyanide (colorless color)
B. Hexokinase
Glucose-6-phosphate formed from glucose and ATP
by hexokinase (HK) is oxidized by NAD in a reaction
catalyzed by glucose-6-phosphate dehydrogenase
(G6PD) to give NADH, which is quantitated
spectrophotometrically at 340 nm.
Reference method, coupling reaction is highly
specific and is not subject to interferences.
Chemical Reaction
glucose + ATP ---hexokinase  Glucose-6-PO4 + NADP
---G6PD  NADH
C. Glucose Dehydrogenase
Automated kinetic assay for the determination of
glucose in blood is described. The method employs
the enzyme glucose dehydrogenase in the presence
of mutarotase, with nicotinamide adenine
dinucleotide as hydrogen acceptor.
••••••••••••••••••••
 It is a document where it is being listed all of the
people involved in investigating specifically on
how the specimen is being processed.
Patient should remained in same position for 30
minutes before specimen is collected.
 Patient is advised to sat down on a chair within
30 minutes before extraction since there could
be variations in some blood analytes.
Three phases in the laboratory
Pre-analytic phase - this particular type of phase tend
to conduct series of performances laboratory out
which pertains to before the testing proper.
Analytic phase - pertains to the root word analysis. This
type of phase were in the specimen tend to be assay in
the laboratory.
Post analytic - as a word goes or the brief exposed which
is after analysis. We are dealing with the results of your
test.
Controllable variables
These types of variables could induced series of
interferences during the testing, because if you
underwent such kind of activities, there's a big possibility
of erroneous results.
Proper identification of patient and his/her specimen
 An essential element to ensure proper specimen
for testing.
 For the prevention on that particular specimen
won't not be transferred or won't not be
reported to other patients.
 An essential integral part for us to undergo
laboratory essay.
At least (2) permanent identifiers (ex. Patients names
[last and first], date of birth, medical record number
(with the same info contained on the test requisition
from and inside the laboratory).
Specimen for medico legal purposes
 Chain of custody system must be established to
ensure all persons handled/ processed the
specimen are identified.
Tourniquet application of > 1 minute induces
hemoconcentration.
 If more than 1 minute, expect that the blood
extracted is highly concentrated.
Related sized needle should be used to avoid hemolysis.
 Consider the size of the needles, there's a big
possibility that the RBCs that you have extracted
will be hemolyzed.
Evacuated Tube System - preferred to use of a syringe
to minimize hemolysis; blood collected into one type
of tube will never be transferred into another tube.
 There's a contamination with other types of
tubes, because some tubes tend to have
anticoagulants, there will be again an erroneous
result.
Plasma - allows more rapid processing of specimens
for chemistry tests, but anticoagulants may interfere
with some analytic methods.
Urine (1 morning) - most concentrated; appropriate
for microscopic exam.
st
 The urine obtained after you sleep for the entire
night is the first morning urine.
Urine (24 hours) - appropriate for quantitative
measurements.
CSF or Cerebral Spinal Fluid and abnormal fluids such
as pleural or ascetic fluid – collected in sterile
conditions, chem test should be performed on the
specimen in the 1 tube, and the 2 tube used for
culture.
st
nd
 CSF is the fluid in our head. The purpose of that
cerebral spinal fluid is precaution or to protect





our brain at the same time it contains nutrients
for it to give to our nerve cells, it contains also
waste products.
Pleural and acetic fluid - these types of fluid are
under serous fluid. These serous fluid are
pertaining to three types that vary in their
location:
Pleural serous fluid - fluid lines our lungs.
Pericardial serous fluid - fluid lines our heart or
outside our hardest surface of our heart.
Peritoneal serous fluid or acidic fluid - fluid lines
our abdominal cavity.
Function of these fluids, The fluid actually passes
through the visceral layer and the parietal layer.
And order for it to avoid friction between the
organ and cage.
Thixotropic polymer gel used
 The tube of choice for performing patient
extraction but other materials is in laboratory,
and execute travel.
 The other function of the gel, forms barrier
between the separated serum or plasma and
cells.
Centrifugation of specimens should be done within 2
hours of blood collection.
 If it is longer than two hours, you would expect
that there's a drastic change on the quantity of
the analytes.
Physiologic Variables
POSTURE
From lying to standing.
INCREASE
DECREASE
- Secretion of catecholamine
- Aldosterone
- Angiotensin II
- Renin
- ADH
- Reduction of blood
volume about 10%
PROLONGED BED REST
INCREASE
DECREASE
Blood hematocrit
(10%
within 4 days)
Nitrogen secretion
(urinary secretion by up to
15% after
2 weeks)
Calcium secretion (7
weeks by a maximum of
about
60%)
Sodium, potassium,
phosphate, and sulfate
- Plasma and
extracellular fluid (start
of bed rest) - Plasma 1,25
– dihydroxyvitamin D and
25- hydroxyvitamin D
(20%) - Aspartate
aminotransferase
activity - Serum
potassium (0.5 mmol/l
over 3 weeks) Hydrogen ion excretion
Plasma cortisol
Vanillyl mandelic
acid (end product of
catecholamine)
EXERCISE
Changes in concentration of analytes result from exercise
are largely due to shifts of fluid between intravascular
and interstitial compartments and changes in hormone
concentration in activity and by the loss of fluid due to
sweating.
INCREASE
DECREASE
Beta
endorphin
(neurotransmitter) and
catecholamine (adrenal
- Arterial pH and pCO2
(assess lung function)
- Cellular ATP
medulla; fight/ flight
response) Blood glucose
Plasma pyruvate and
lactate - Serum creatinine
(product of
muscle metabolism)
concentration
AST, LD, CK (CK-MM),
aldolase (skeletal muscle
enzyme)
Plasma lactate
Plasma protein
Plasma fibrinolytic
activity - Cortisol, aldosterone,
growth
hormone, prolactin
Leukocyte count
Serum urea and
creatinine
- Serum cholesterol and
triglycerides - Plasma
insulin - Blood pH,
oxygen saturation
and venous
bicarbonate
concentration
CIRCADIAN VARIATIONS
Factors contributing to such variation include posture,
activity, food ingestion, stress, daylight or darkness,
sleep, or wakefulness.
TRAVEL
INCREASE
DECREASE
- Serum glucose and
triglyceride (20hour flight) Blood and plasma values
(space travel) - plasma ADH,
atrial natriuretic peptide,
growth hormone, cortisol
and corticotropin.
- Plasma renin activity and
aldosterone (space travel)
DIET
INCREASE
DECREASE
Protein diet
Plasma urea concentration,
serum, cholesterol,
phosphate, urate, and
ammonia concentration.
Carbs diet ALP
& LD
High fat diet
Triglycerides & Nitrogen
pool
Low fat diet Serum
lactate
dehydrogenase (LD)
Ingestion of
monounsaturated fat
Cholesterol and LDL
Low sucrose intake
Total lipid and
phospholipid
concentration
Cholesterol and
TAG concentration - Lipid
concentration - Serum
creatinine concentration
Trace elements
(copper, selenium, and
zinc)
Vitamin B12
MALNUTRITION
- Gamma globulin (yet not
fully compensate for the
decrease of other proteins.)
plasma cortisol
Most protein (TP,
albumin, prealbumin, and
beta-globulin) Concentration:
complement C3 retinolbinding globulin,
transferrin and
prealbumin.
Plasma
concentration of
lipoproteins. - Urea
nitrogen and creatinine
(decrease skeletal mass
and creatin clearance).
Plasma
concertation of total t3
and t4
RBC and plasma
folate concentration Vitamin b12
Vitamin A and E Blood hemoglobin
concentration
Activity of most
measured enzymes
LONG-TERM FASTING AND STARVATION
Glucagon
Lipolysis
Blood branchedchain amino acids
Aldosterone
secretion
Plasma growth
hormone.
- Blood glucose
- Insulin secretion
- Plasma potassium
- T3 and T4
Plasma TAG
High carb diet
Serum LDL – cholesterol,
serum TAG, serum
cholesterol, serum
protein
FOOD INGESTION
After meal
Glucose and TAG, Serum
concentration, & ALT and
AST
After fatty meal
ALP (intestinal isoenzyme
After ingesting protein (rich
meal in evening) Serum
urea nitrogen, phosphorus,
and urate Large protein
meal at lunch Serum
cholesterol and growth
hormone
After meal
- Plasma chloride (HCL
secretion)
INGESTION OF SPECIFIC FOODS AND BEVERAGES
Bananas and
vegetables that contain 5hydroxy tryptamine or also
called serotonin (5- HIAA)
Caffeine – coffee, tea, and
cola.
Secretion
epinephrine - Excretion
catecholamine and their
metabolites. - Plasma glucose
concentration
Cortisol
Plasma renin activity
- Excretion of sodium
potassium diuresis - Plasma
free fatty acids
Serum TAG
concentration
Secretion of gastric
juice,
HCL, and pepsin
Serum gastrin
Excretion of RBC and
renal
tubular cells in urine
(diuresis)
Onions – reduce
plasma glucose and
insulin. - Garlic – reduce
serum cholesterol
Decrease of
serum cholesterol
Sodium, potassium,
calcium, magnesium in urine.
LIFESTYLE
SMOKING
INCREASE
DECREASE
- Nicotine increases
epinephrine in plasma Glucose, plasma lactate,
plasma growth hormone,
-Bicarbonate
concentration and
pancreatic juice volume Serum vitamin B12
Quality management - overall process that
encompasses method, quality assurance,
benchmarking, and other aspects of provide for quality
improvement as a means to meet set standard.
Quality assurance
 Assure that quality processes or the materials
are really that standard to what we want
specifically the vision that we have set which is
to give reliable and accurate results towards
the patient.
VEGETARIANISM
- pH urine – due to reduce
intake of precursors of acid
metabolism.
- VLDL – cholesterol
 Include maneuvers encountered in the pre
analytic analytic and post analytic phase phases
of testing.
 Monitors quality performance starting from the
ordering of a laboratory determination to its
reporting, the interpretation of results, and
then application to patient care.
plasma cholesterol, TAG, LDL
– cholesterol, cortisol, blood
RBC count,
carboxyhemoglobin, WBC
count.
Volume and acid
secretion in our digestive
system (nicotine is a potent
stimulant of the secretion of
gastric juice)
Serum
immunoglobulin A,
G, and M
Serum IgE
Carcinoembryonic
antigen
Plasma fibrinogen
- Sperm count; increase
abnormal forms;
decrease motility
ALCOHOL INGESTION
Hypoglycemia
GGT activity has been extensively studied and increase
activity of the enzyme is used as a marker of persistent
drinkin
- Plasma testosterone
Blood glucose
concentration
TAG
Plasma
concentration of aldosterone
Activity of GGT,
isocitrate dehydrogenase and
ornithine
carbamoyltransferase - HDL
cholesterol concentration Concentration of
catecholamines
Plasma LH
concentration
Activity of AST and
ALT - Increase MCV – may
relate to folic acid deficiency
or direct toxic effect of
alcohol on RBC precursors.
DRUG ADMINISTRATION
- Creatinine kinase,
aldolase, and LD (skeletal
muscle) - Serum when drugs
administered
intramuscularly. Oral
contraceptives - Increase
plasma thyroid hormones,
glucocorticoids, and sex
steroids.
PHENYTOIN
Treatment for epilepsy
Diuretic
drugs
Decrease
plasma
potassium and sodium
Thiazides
- Decrease potassium in
blood; hyperglycemia;
increase lipids in plasma.
Hyperglycemia and glycosuria by inhibiting insulin
secretion
- ALP activity
- Activity of serum GGT.
- Serum ALP activity
Serum calcium
and phosphate
concentration - Serum
total bilirubin - Serum FSH
and sperm count
Serum thyroxine
and T3
Calcium
concentration
(plasma)
Benchmarking allowing yourself to know about the
processes or other methods or the things that the other
hospital institutions are doing. You will have the idea on
how to work out on institution.
Other aspects of provide for quality improvement as a
means to meet set standards.
METHOD EVALUATION is used to verify the
acceptability of new methods prior to reporting patient
results.
Quality control - continue the quality of the method.
 Entire testing process is directed with an overall
goal improving the accuracy of the laboratory
result.
 Concerned with the analytic phase of Quality
Assurance; monitors the over-all reliability of
laboratory results in terms of accuracy and
precision.
The Objectives of Quality Control,
•
•
•
To check the stability of the machine
To check the quality of the reagents
To check technical errors
Kinds of Quality Control,
1. Intralaboratory
- Internal quality control
- Involves the analysis of control samples
together with the patient's specimen
- Important for the daily monitoring of accuracy
and precision of analytical methods.
- Detects both random and systemic error
2. Interlaboratory
- External quality control
- Involves proficiency testing program
- Maintains long term accuracy
- Difference of >2 in the results indicate
nonagreement
Characteristics of Ideal Quality Control Materials,
•
•
•
•
•
•
Resembles a human sample
Inexpensive and stable for long periods
No communicable diseases
No known matrix effect
Known analyte concentration
Convenient packaging for easy dispensing and
storage
ANALYTICAL VARIATIONS
Types of Error In Laboratory Testing
Random error - present in all measurements due to
chance or an unpredictable cause.
Examples of REs: Pipetting error, Temperature
fluctuation, Improper mixing of sample and reagent
Systemic error - influences observations consistently in
one direction.
Examples of SEs: Calibration error, Deterioration of
reagents, Unstable reagent blank, Contaminated
solutions, Failing instrumentation, Changes in standard
concentration
Clerical error - highest frequency is due to handwritten
labels and request forms.
Interpretation of Quality Control Results,
Shewhart Levey- Jennings Chart - where the control
results are plotted. LJ is one way for us to also identify
errors during the analytic phase, thus, performing
quality control processes.
Westgard control rules - used to identify analytical
error. Established to determine the acceptability of a
result based of predetermined SD from QC in
LeveyJennings QC Chart.
1:2S rule - Occurrence of control value outside of -2SD
to +2SD; warning totrigger inspection of control data
1:3S rule - Reject when one observation exceeds the
mean -3SD to +3SD limit; random error.
2:2S rule - Reject when two consecutive observations
exceed the same mean +2SD limit or the same mean
2SD limit; systematic error.
4:1S rule - Reject when four consecutive control
observations exceed the same mean +1SD limit or the
same mean -1SD limit; systematic error.
10:x rule - Reject when ten consecutive control
observations fall on one side of the mean; systematic
error.
R:4S rule - Reject when one control in the run exceeds
its mean +2SD limit; and another exceeds its mean -2SD
limit; random error..
Delta Check - Compares the result obtained to one
specimen with the previous results obtained for the
same patient.
Sensitivity - refers to how many individuals who are
known to have a disease will be picked up by a given
method as having the disease; total number of true
positive in a population diagnosed to be positive.
Specificity - Measures how many truly negative
individuals are there in a population without the
disease
Positive predictive value - Refers to how good is the
test in predicting which individuals have the diease;
probability that a patient with a positive test does not
have the disease for which he is tested.
Negative predictive value - Probability that a patient
with a negative result is free of the disease for which
the test is being performed.
Efficiency of the Test - Probability that a patient test
result (positive or negative) correctly responds with the
disease state for which he is being evaluated.
Reference values - Determined by performing a specific
measurement on a large number of healthy individuals
often grouped by age and sex
Accuracy - The extent to which the mean measurement
is close to the true value
Precision - Reproducibility of a laboratory
determination when it is run repeatedly under identical
conditions.
Standard deviation - Measure of dispersion of the
values around the mean.
Reference laboratories - 68% confidence limit (within
1SD to +1SD around the mean)
Hospitals and laboratories - 95% confidence limit
(within -2SD to +2SD around the mean)
Reference materials - Solutions with a known amount
of a substance; used to calibrate an assay method.
Standards/calibrators - Reference materials in the
clinical chemistry laboratory.
••••••••••••••••••••
Fatty acids - are monocarboxylic acids that form fats
and oils. It is the building blocks of the fat in our bodies
and in the food we eat. If glucose (a type of sugar) isn't
available for energy, the body uses fatty acids to fuel
the cells instead.
Phospholipids - are membrane lipids that formed by
alcohol, phosphate, and fatty acid. These are crucial for
building the protective barrier, or membrane, around
your body's cells. In fact, phospholipids are synthesized
in the body to form cell and organelle membranes.
Triglycerides - are energy storage lipids that formed by
esterification of three fatty acids to a glycerol molecule.
These are fats from the food we eat that are carried in
the blood.
Cholesterol - is a membrane lipid that is synthesized in
the liver. It give strength to cell membranes. The excess
of it in the body leads to gall stones and plaque in the
arteries.
Chemical methods for analyzing cholesterol:
a. Zlatkis, Zak and Boyle
In these methods, the colorimetric reaction is
performed directly on serum or plasma.
b. Carr-Drekter
These methods introduce an extraction step,
primarily to remove proteins prior to color
development.
c. Abell-Kendall
Standard reference method for cholesterol
determination; the method avoids interference by
bilirubin, protein, and hemoglobin.
d. Schoenheimer-Sperry
Cholesterol is extracted with alcohol-ether and the
free-cholesterol is then determined by precipitating
it with digitonin.
Chemical methods for analyzing triglycerides:
Van Handel-Zilversmith - Colorimetric method for TAG.
Hantzsch - Fluorometric method for TAG.
Plasma Proteins:
Prealbumin
o
o
Also called transthyretin; synthesized primarily
by the liver.
Carry thyroxine (a thyroid hormone) and
vitamin A throughout the body.
o
Prealbumin blood test helps your doctor
determine if you’re getting enough nutrients namely, protein -- in your diet.
Albumin
o
o
o
A protein that is synthesized in the liver.
Albumin enters the bloodstream where it helps
carry vitamins, enzymes, and other important
substances. Albumin also helps prevent fluids
from leaking out of the bloodstream.
To measure albumin, the laboratory could use
bromocresol green (BCG) and bromocresol
purple (BCP) method.
Globulin
o
o
o
Group of proteins in your blood. They are made
in your liver by your immune system.
Globulins play an important role in liver
function, blood clotting, and fighting infection.
A globulin electrophoresis, is a blood test that
measures levels of a group of proteins called
globulins.
Different laboratory techniques for the determination
of protein:
Standard protein electrophoresis – used to separate
groups of proteins in blood serum. It involves exposing
serum placed in a special type of gel to an electric
current. This causes the different types of proteins to
move and group together.
High-resolution protein electrophoresis – uses a higher
voltage coupled with a cooling system and a more
concentrated buffer; separates serum proteins into as
many as 12 bands, detects small monoclonal bands and
differentiates unusual bands or prominent increases of
normal bands.
Kjeldahl method – Reference method for total protein,
measures nitrogen content. Acid digestion converts
nitrogen in protein into ammonium ion which is
measured.
Refractometry – measure the degree to which the light
changes direction, called the angle of refraction. A
refractometer takes the refraction angles and correlates
them to refractive index (nD) values that have been
established.
UV absorption/Direct spectrophotometer method –
determine the quantity of proteins in the sample by
using the maximum absorption at 280 nm. Based on
the absorbance of UV light by the aromatic amino
acids tryptophan and tyrosine, and by cystine, disulfide
bonded cysteine residues, in protein solutions.
Turbidimetry – light blocking: treat sample with TCA,
Sulfosalicylic acid (SSA) to form precipitate (of proteins).
Clumps form (precipitate) which will block the amount
of light that reaches the detector.
Biuret method – formation of violet-colored chelate
between Cu²+ ions and peptide bonds. Absorbance of
the colored chelate formed is measured at 540 nm. The
color formed is proportional to the number of peptide
bonds present and reflects the total protein level.
Lowry method – used biruet reaction in the first step
which is testing for peptide bonds. Then you use your
copper-protein complex in step two and react it with
phosphotungstic acid and phosphomolybdic acid to
form tungsten molybdenum blue.
Folin-Ciocalteau – requires a ring structure to react with
phosphotungstic acid to produce tungsten molybdenum
blue.
Ninhydrin method – detect the presence of ammonia,
primary/secondary amines, or amino acids. This test
involves the addition of ninhydrin reagent to the test
sample that results in the formation of deep blue color,
often termed as Ruhemann's purple, in the presence of
an amino group.
Dye-binding technique – protein binds to dye and
causes a spectral shift in the absorbance maximum of
the dye.
Albumin method – measure albumin directly without
any pretreatment of samples, such as serum, plasma,
urine, and biological preparations. The intensity of the
color, measured at 620 nm, is directly proportional to
the albumin concentration in the sample.
4 General Properties Of A Protein
][ Net charge - A protein's net charge is zero at the
isoelectric point (pI), positive at pHs lower than the pI,
and negative at pHs higher than the pI.
][ Isoelectric point - The isoelectric point of a solution is
defined as the pH at which the net charge on protein is
zero (pH). The isoelectric point of a protein is significant
since it is at this point that the protein becomes the
least soluble and thus unstable.
][ Solubility - The pH of a solution affects the solubility
of proteins. Solubility is lowest near the isoelectric point
and rises as acidity or alkalinity increases. As a result,
they will be more soluble than when they are in their
isoelectric condition.
][ Nitrogen content - Proteins are made up of carbon,
oxygen, hydrogen, nitrogen, and sulfur. The presence of
nitrogen atoms in proteins distinguishes them from
pure carbohydrates and lipids, which do not contain
nitrogen atoms.
Myoglobin - It is the primary oxygen-carrying protein
found in striated skeletal and cardiac muscle,
accounting for approximately 2% of total muscle
protein.
Cardiac Troponins - It is a cardiac regulatory proteins
that control the calcium mediated interaction between
actin and myosin.
Natriuretic Peptides - are substances made by the
heart. Two main types of these substances are brain
natriuretic peptide (BNP) and N-terminal pro b-type
natriuretic peptide (NT-proBNP) which are circulating
hormones of cardiac origin that play an important role
in the regulation of intravascular blood volume and
vascular tone.
Cystatin C - is a protein that is produced by the cells in
your body. It has been used as an estimate of the
severity of CKD because a high level of cystatin C is
associated cardiovascular disease.
None Protein Nitrogen (NPN)
Urea
 Protein metabolism produces urea, which is the
most common excretory product. It is made up
of amino groups (NH2) and free ammonia
produced during protein degradation in the
liver.
 It's been used topically for various dermatitides
and as a diuretic in kidney function tests.
 Urea levels are measured to: ∆ Assess renal
function
∆ Define hydration status ∆ Determine
nitrogen balance, aid in the diagnosis of
renal disease
∆ Check dialysis adequacy.
Uric Acid
 Produced when purine nucleic acids are
catabolized.
 Uric acid levels are assessed to:
∆ Confirm gout diagnosis and treatment ∆
Prevent uric acid nephropathy during
chemotherapy
∆ Assess inherited purine metabolism problems
∆ Detect kidney dysfunction ∆ Aid in the
diagnosis of renal calculi.
Creatinine
 Formed from creatine and creatine phosphate
in muscle and is excreted into the plasma at a
constant rate related to muscle mass.
 High levels of it in the blood might indicate that
the kidneys are not working correctly.
 Creatinine measured to:
∆ Determine the sufficiency of kidney function
∆ Determine the severity of kidney damage
∆ Monitor the progression of kidney disease.
Ammonia
 Produced by the action of bacterial enzymes on
ingested amino acids.
 It is absorbed from the gastrointestinal system
and transferred to the liver via the portal vein,
where it is mostly converted to urea. Although
free ammonia is poisonous, it is present in low
amounts in the plasma.
 High ammonia levels in the blood are most
often caused by liver disease. Hepatic failure,
Reye's syndrome, and hereditary abnormalities
of urea cycle enzymes are all clinical diseases in
which blood ammonia content is useful.
 The concentration of ammonia in the
bloodstream is a better indication of illness
severity.
Chemical Reaction for NPN Measurement and
discuss each. UREA
1. Chemical Method
(Fearon method)
Chemical Reaction
Urea + Diacetyl ----Heat  Diazine + 2H20
The diacetyl, or Fearon, reaction develops a yellow
chromogen with urea, and this is quantified by
photometry.
(GLDH-Coupled enzyme)
Chemical Reaction
Urea + 2H20 ---Urease  2NH4+ + CO3²NH⁴+ + 2-oxoglutarate + NADH ----GLDH  Glutamate
+ NAD+
Urea catalyzed by urease, followed by GLDH coupled
enzymatic reaction of NH₄ + 2-oxoglutarate and NADH
to form glutamate and NAD⁺.
URIC ACID
1. Analytical Method:
Chemical method
(Phosphotungstic Acid Method)
Chemical Reaction
Uric acid + Phosphotungstic acid + 02 + C02 + H20 
Allantoin
Chemical Reaction
A mixture of phosphoric and tungstic acid. Proteins in
serum are precipitated with tungstic acid. Uric acid in
the supernatant reduces the phosphotungstic acid into
tungsten blue in an alkaline medium of sodium
bicarbonate.
NH3 + K2HG14  Brown compound
Enzymatic method
2. Enzymatic method
(Nesslerization)
(Uricase Method)
Iodide and mercury ions react with ammonia under
alkaline conditions to produce a reddish‐brown
complex, which absorbs strongly at 420 nm.
Chemical Reaction
Uric acid + H20 + 02 ---Uricase  Allantoin + C02 +
H202
(Berthelot)
Chemical Reaction
NH3 + Phenol ---CIO–--  Indophenols ---Alkali  Blue
compound
Based on the production of a blue-indophenol
compound when ammonia reacts in an alkaline medium
with phenol and sodium hypochlorite. This basic
colorimetric reaction can be used to quantify both urea
and blood ammonia levels.
The hydrogen peroxide produced is reacted with
choromogen in the presence of peroxidase enzyme,
produces red color, the intensity of which is
proportional to the amount of uric acid present in the
sample.
CREATININE
1. Chemical method
(Jaffe Reaction)
Chemical Reaction
•
Creatinine + Picric acid ---alkaline pH  orange-red
complex
A bright orange-red complex resulting from the
treatment of creatinine with alkaline picrate solution;
the basis of most routine creatinine tests.
2. Enzymatic method
(Creatininase Method)
Chemical Reaction
Creatinine + H20 ---Creatininase  Sarcosine + urea
Enhance the specificity of the Jaffe reaction. Its enzymes
are Creatininase, Creatinase, Sarcosine oxidase, &
Peroxidase
NEGATIVE FEEDBACK MECHANISM
•
Often known as negative feedback
homeostasis. It occurs when some function of
the output of a system, process, or mechanism
act in a manner that tends to reduce the
fluctuations in the output, whether caused by
changes in the input or by other disturbances.
LIQUID CHROMATOGRAPHY
•
•
Also known as Liquid-solid chromatography; is a
technique useful for separating ions or
molecules dissolved in a solvent.
It is a low cost technique.
THIN-LAYER CHROMATOGRAPHY
•
•
Technique used to separate non-volatile
mixtures. It is used to study the purity of the
compound and progress of reaction, and to
identify the various compounds present in the
mixture.
It is widely used because of its simplicity and
relative low cost.
GAS CHROMATOGRAPHY
Technique which separates and analyzes
volatile compounds in the gas phase. It is used
to separate components in a mixture. Two
types: Gas-solid Chromatography& Gas, -liquid
Chromatography.
•
It is a high cost technique.
MASS SPECTROSCOPY
•
Technique that measures the mass-to- charge
ratio of ions. It is used to identify separated
components in a mixture. Two types: Positive
Ionization Mass Spectroscopy & Negative
Ionization Mass Spectroscopy.
>>>>>>>>>>>>>>>>>>TOXICOLOGY<<<<<<<<<<<<<<<<<
TOXICOLOGY is the study of the adverse effects of
xenobiotics in humans. Involves looking for signs that a
patient is under the influence of narcotics or alcohol
Xenobiotics are chemicals and drugs that are not
normally found in or produced by the body.
Three major disciplines: mechanistic, descriptive, and
regulatory toxicology.
Mechanistic toxicology elucidates the cellular,
molecular, and biochemical effects of xenobiotics within
the context of a dose–response relationship between
the xenobiotic and its adverse effect(s).
Descriptive toxicology uses the results from animal
experiments to predict what level of exposure will
cause harm in humans. This process is known as risk
assessment.
Regulatory toxicology, combined data from mechanistic
and descriptive studies are used to establish standards
that define the level of exposure that will not pose a
risk to public health or safety.
There are also a number of specialties within toxicology,
including forensic, clinical, and environmental
toxicology.
Forensic toxicology is primarily concerned with the
medical and legal consequences of exposure to
chemicals or drugs.
Body Tissues/Homogenates, in cases of violent death,
blood or urine may be unavailable so this can be used
to screen and quantitate drug levels.
Clinical toxicology focuses on the relationships between
xenobiotics and disease states.
Salicylates is the family of drugs is classified as mild
analgesics, pain relievers, and antipyretics such as
aspirin; frequently seen in accidental overdose by
children.
Environmental toxicology includes the evaluation of
environmental chemical pollutants and their impact on
human health.
#Another goal of environmental toxicology is to monitor
occupational health issues and to increase public health
biomonitoring efforts nationwide.
Xenobiotics are defined as exogenous agents that can
have an adverse effect on a living organism. This term is
more often used to describe environmental exposure to
chemicals or drugs. Examples of environmental drug
exposures include antibiotics and antidepressants.
Poisons are also exogenous agents that have an adverse
effect on a biological system; however, this term is
more often used when describing substances from an
animal, plant, mineral, or gas.
Toxins are endogenous substances biologically
synthesized either in living cells or in microorganisms.
Examples include botulinum toxin produced from the
microorganism, Clostridium botulinum, hemotoxins
produced from venomous snakes, and mycotoxins
produced from fungus.
Alcohol
-
-
-
-
lungs and the immune system are also affected
by alcohol.
Alcohol may also serve to intensify the
progression of viral infections, autoimmune
diseases and cancer.
#1 drug abused in the US, and is frequently
seen in toxicology testing, and acts as both a
depressant and vasodilator.
Alcohol blood testing detects evidence of
alcohol use. Can also be measured in samples of
a person’s sweat, hair, urine, breath, and saliva.
Cocaine
-
The main function of toxicology is to identify drugs in
cases of acute intoxication and/or poisoning.
-
There is no true specimen of choice for toxicologic
analysis as the type of specimen is dependent on the
desired test and/or suspected toxic agent.
-
Urine is most widely used specimen for toxicology
screening tests. Rarely used for quantitative analysis as
urine drug concentration and serum concentrations do
not correlate.
Liver is a primary target for the detrimental
effects of alcohol since this substance of abuse
is mainly metabolized by liver cells. However,
other organs, including brain, gut, pancreas,
The target organs are Central Nervous System
(CNS) and the Cardio-vascular (CV) system.
Abuse of cocaine leads to strong psychological
dependence.
Experts use several methods to detect cocaine.
The tests detect benzoylecgonine, which is a
marker for cocaine. The following test methods
are Urine, Saliva, hair, and blood testing.
Acetaminophen
-
Whole Blood is the preferred specimen for Blood
Alcohol and carbon monoxide cases.
-
Serum/Plasma is the most widely used specimen for
toxicology quantitative testing.
-
The major target organ of APAP toxicity is the
liver. In fact, APAP is the principal cause of
acute liver failure (ALF).
Overdose of acetaminophen can cause liver
failure or death.
Acetaminophen (Tylenol) Level, Acetaminophen
level is measured in plasma or serum for the
evaluation and management of potential
toxicity or suspected/known suicide attempt.
Amphetamines
-
-
-
Common names are speed, "uppers",
stimulants; first synthesized an anti-asthmatics;
act to increase CNS activity.
Therapeutic drugs used for narcolepsy &
attention deficit disorder. Stimulants with a
high abuse potential. Produce initial sense of
increased mental & physical capacity &
perception of well-being. Initial effects followed
by restlessness, irritability, & possible psychosis.
Overdose: hypertension, cardiac arrhythmias,
convulsions, death.
Testing: urine analysis, immunoassay screening,
confirmation by liquid or gas chromatography.
Method of toxicology testing include: EIA, FPIA, &
Chromatography
EIA and FPIA, this method of toxicology testing involves
antibodies directed against the drug to produce a color
in which the color is proportional to the drug
concentration.
Chromatography is the most specific toxicology testing
method to date but is primarily limited to forensic labs
due to cost, time, and demand.
Therapeutic Drug Monitoring (TDM)
-
-
Barbiturates commonly known as "downers" or
sedatives; Frequently seen in drug abuse and suicide
attempts.
Benzodiazepines classified as mild tranquilizers; most
frequently prescribed drug in the US; Two commonly
seen: Valium and Librium
Aspirin (acetylsalicylic acid)
-
-
Common analgesic, antipyretic, &
antiinflammatory drug. a
Toxic Effects: metabolic acidosis/ketoacidosis,
inhibition of the Kreb's Cycle, hyperventilation,
acid-base disturbances, respiratory alkalosis
Contraindicated in children and adolescents
with Reye's Syndrome.
Therapeutic Drugs any have a narrow margin between
therapeutic range and the toxic level; may not be taken
correctly or taken too much putting the patient in a
toxic condition.
Heavy Metals, most of these agents come from sources
in the environment; public health problem in lower
socio-economic housing areas where lead-based paint
still exists.
Assay of serum drug concentrations for drugs
displaying a high correlation between their
serum concentrations and their pharmacologic
effect.
Specimen of Choice for TDM: Serum - Benefits:
∆ Aids proper dosing of prescriptions
∆ Helps ensure patients compliance w/ meds ∆
Allows investigation of symptoms related to
toxicity of the meds.
Ethyl Alcohol Metabolism:
-
Metabolized into acetaldehyde by Alcohol
dehydrogenase.
Acetaldehyde is converted to Acetic Acid by
Acetaldehyde dehydrogenase.
By products of ethyl alcohol metabolism
include: CO2, H20, ATP, Cholesterol, Fatty Acids
Methyl Alcohol Metabolism:
-
Metabolized to formaldehyde by Alcohol
dehydrogenase
Formaldehyde breaks down into Formic acid
which can cause blindness.
Medical Bat
-
Strictly for medical reasons Ordered by a
physician
No special handling or COC
Results given to physician
Cannot be used for legal purposes Legal Bat
-
Done for purposes of legal actions
-
Only base commander may authorize but
others acting on their behalf may execute
Must have individual consent of civilians and
dependents
Consent of military member is not required
Results ONLY given to appointed individuals
DIRECTOR OF PATIENT AFFAIRS is responsible
for releasing the results to proper authorities
Must use NON-ALCOHOLIC SKIN PREP
THC (tetrahydrocannabinol)
-
Most potent and abundant cannabinoid
-
Wide range of therapeutic roles & are commonly used.
(Barbiturates, Benzodiazepines)
Barbiturates
-
Cannabinoids
-
Group of psychoactive compounds. Produce
sense of well being & euphoria. Associated with
impairment of short-term memory &
intellectual function in chronic users. Overdose
not associated with specific physiologic toxic
outcomes.
THC will test positive on a saliva test within one hour of
use but not test positive 12 hours after use
THC will test positive on a urine test within 2-5 hours of
use but not test positive anywhere from 12 hours after
use in a one-time user to 30 days plus in a heavy user.
THC will test positive on a hair test about 7 days after
using but not test positive approximately 90 days after
using
Gas chromatography with mass spectroscopy
-
Works on the principle that a mixture will
separate into individual substances when
heated.
Opiates
-
A class of substances capable of analgesia,
sedation, & anesthesia; high abuse potential.
Opium, morphine, codeine.
Chemically modified: heroin, dilaudid,
oxycodone, hydrocodone
Methadone
Analog of morphine and heroin.
Used medically as an analgesic.
Treatment for opioid dependency.
More toxic and longer duration.
Toxicity is difficult to determine because deaths
are often complicated with withdrawal
symptoms and drug-seeking behaviors.
phenobarbital, amobarbital, secobarbital,
pentobarbital. (not used often, potency is very
high, LD50/TD50 close to ED50)
Benzodiazepines
-
Diazepam (valium), chlorodiazepoxide (librium),
lorazepam (ativan).
GC/MS (Gas Chromatograph-Mass
Spectrometry), LC/MS (Liquid Chromatography-Mass
Spectrometry)
-
gold standard confirmatory tests (toxicology)
>>>>>>>>>>>>>>>>ENDOCRINOLOGY<<<<<<<<<<<<<<<
HYPOTHALAMIC AND PITUITARY FUNCTION
The hypothalamus’ main role is to keep the body in
homeostasis as much as possible. Homeostasis means a
healthful, balanced bodily state.
Hormones from the pituitary gland controls the
functions of many other glands in the body such as the
ovaries, the testes, the thyroid gland, and the adrenal
cortex.
ADRENAL FUNCTION
The adrenal gland is multifunctional organ that
produces the steroid hormones and neuropeptides for
life.
The adrenal glands have a rich blood supply via three
main arteries:
1)
Superior adrenal artery – arises from the
inferior phrenic artery.
2)
Middle adrenal artery – arises from the
abdominal aorta.
3)
Inferior adrenal artery – arises from the renal
arteries.
Steroid hormones are metabolized in liver and secreted
in feces and urine.
Three zones/regions of adrenal cortex:
 Zona glomerolusa – synthesize
mineralocorticoids such as aldosterone.
 Zona fasiculata – synthesize glucocorticoids,
such as cortisol, and small amount of
androgens.
 Zona reticularis – produces and secretes
androgens, such as dehydroepiandrosterone
(DHEA) and DHEA sulfate.
Adrenal Medulla
Functioned as an atypical sympathetic ganglion.
Secretes catecholamines directly in the circulation in
lieu.
Medullary catecholamine products serve as first
responders to stress.
Tumors of chromaffin cell (pheochromocytomas)
maintain capacity to synthesize and store
catecholamines)
Secretes catecholamine - epinephrine (adrenaline), and
norepinephrine (noradrenaline).
Derived from Tyrosine = Fight-or-flight response
Adrenal insufficiency
-
Inadequate hormone secretion from the
adrenal cortex.
Cortisol level is <3 μg/ dL in the morning (highly
suggestive)
Primary adrenal insufficiency: also called Addison's
disease. In this rare condition, the adrenal glands do not
work properly and cannot make enough cortisol (a
“stress” hormone) despite adequate stimulation.
Diagnosis,
 It is made by performing an ACTH stimulation
test.
 The test is performed at 8 AM in the fasting
state.
 The patient is then given 250 μg of cosyntropin
(synthetic ACTH) intravenously and cortisol
level is checked at 30 and 60 minutes after
ACTH administration.
 A cortisol of 18 or greater at either 30 or 60
minutes post ACTH time point suggests normal
adrenal function.
Primary adrenal insufficiency Includes both
glucocorticoid replacement (prednisone or
hydrocortisone) and mineralocorticoid replacement
(fludrocortisone).
Secondary adrenal insufficiency: adrenal gland function
is preserved but the stimulus for hormone release is
insufficient or absent.
Diagnosis,
 The ACTH stimulation test may be normal or
abnormal based on the duration of the disease.
 If secondary adrenal insufficiency is suspected,
metyrapone suppression testing can be done.
Metyrapone is an inhibitor of adrenocortical
steroid. It blocks certain enzymes in the
steroidogenesis pathway.
 It is suggested in patients with a near-normal
response to a 250-μg cosyntropin test but with
an abnormal response to metyrapone.
 An alternative is to do an insulin tolerance test
(ITT). The ITT should be avoided in those with
cardiovascular disease and seizure disorder.
Secondary adrenal insufficiency glucocorticoid
replacement is required since aldosterone production
remains normal.
Cushing Syndrome
o
o
Occurs when body is exposed to high levels of
the hormone cortisol for a long time.
The most common cause of Cushing syndrome,
sometimes called hypercortisolism, is the use of
oral corticosteroid medication.
Cushing's disease term used when the source of
elevated ACTH is the pituitary gland. The most common
reason for cortisol excess accounting for about 70 % of
cases.
Diagnosis,
 Urine free cortisol collected over 24 hours (on
two occasions to be considered positive
 Late night salivary cortisol level
 Dexamethasone suppression testing (1 mg
overnight or 2 mg over 48 hours). The test is
considered negative if the AM cortisol level is
less than 1.8 μg/dL.
Antihypertensive drugs and many other
medications interfere with accurate
catecholamine measurement.
Adrenal Androgen
Produced as by-products of cortisol synthesis that are
regulated by ACTH.
Primarily produce DHEA and multiple.
DHEA and DHEAS
• Are precursor to more active androgens and
estrogens
• Have minimal androgenic activity, adverse effects are
caused by conversion to active androgens in adrenal
and peripheral tissue.
• Men derive less than 5% of their Testosterone
• Women rely on the adrenals for 40 % to 60 % of their
daily testosterone production
Cushing's Syndrome term used if other forms of cortisol
excess.
• Androgen production peaks in young adults and
progressively declines with age.
Diagnosis,
Androgen Excess
 Surgical resection (adrenal or ectopic)
 Medical therapy, if hypercortisolism persists
after surgical intervention.
 Bilateral adrenalectomy, if medical therapy is
unable to suppress cortisol levels and the
patient has infectious/thrombotic
complications from cortisol excess.
 Adrenal enzyme inhibitors: ketoconazole,
adrenolytic agents (mitotane), pituitary ACTH
secretion suppressors (pasireotide or
cabergoline), and glucocorticoid receptor
blockers.
Urine and Plasma Catecholamine
Measurements
Urine catecholamines are assayed using liquid
chromatography, fluorometry, and LC-tandem
mass spectrometry.
• Can cause ambiguous genitalia in infant girls and
precocious puberty in children of both sexes •
Virilization in women and children
• In women, androgen overproduction can cause
infertility with masculinizing effect .
• In men, excess adrenal androgens converted to
estrogen can also cause infertility with feminizing
effect.
Diagnosis for Excess
Androgen Production
• Less than 10% of DHEAS and DHEA are produced by
the gonads; therefore, high DHEAS and DHEA
production strongly suggests adrenal
hyperandrogenism
• Plasma DHEAS, DHEA, or urinary 17-ketosteroids can
identify patients with adrenal causes of pathologic
masculinization and feminization.
GONADAL FUNCTION
(Testes)
Androgen - are hormones that contribute to growth
and reproduction in both men and women.
Spermatogenesis
An ongoing differentiation process that occurs in the
seminiferous epithelium in the testis in males to
produce spermatozoa (sperm) and is sustained by a
tissue- specific stem cell termed the “ spermatogonial
stem cell.”
(Ovaries)
If no Y chromosome or TDF (testes-determining factor) ovary formed
Only 400,000 oocytes remain at puberty, and only 400
to 500 will be released from the ovary during the
reproductive life of the female.
Estrogen and progesterone hormone production.
2 to 5 cm in length, weighs 14 g.
Hormonal Production By The Ovaries
 Estrogen: promotes breast, uterine, and vaginal
development.
 Progesterone: induces secretory activity of
endometrial glands
 Androgens: help with libido but in excess, lead
to hirsutism
o
o
Starts with extrusion of ovum, about 36 hours
after LH surge (ovulation)
Produce more progesterone than estrogen to
prepare the uterus for implantation.
Menstrual Cycle Abnormalities
Amenorrhea – absence of menses
Primary, never menstruated by age 16
years.
Secondary, atleast one menstrual cycle in
3 to 6 months.
Oligomenorrhea – infrequent irregular
menstrual bleeding
Menorrhagia – uterine bleeding in excess of 7
days is dysfunctional
Hypogonadotropic hypogonadism –
gonadotropin (FSH and LH) deficiency resulting
in decreased sex steroid production.
Hypergonadotropic hypogonadism –
characterized by ovarian failure resulting in
elevation of FSH concentrations, with or
without LH elevations.
Polycystic Ovary Syndrome – this common
disorder can present in many ways: infertility,
hirsutism, chronic anovulation, glucose
intolerance, hyperlipidemia or dyslipidemia,
and hypertension.
Hirsutism – abnormal, abundant,
androgensensitive terminal hair growth in areas
in which terminal hair follicles are sparsely
distributed or not normally found in women.
THYROID GLAND
The Menstrual Cycle
Positioned in the lower anterior neck and is shaped like
a butterfly.
Follicular phase
Made up of two lobes resting on each side of the
o
Begins with onset of menses and ends on day of
LH surge, right before ovulation o A rise in
FSH stimulates estrogen production
and egg maturation during that phase
Luteal phase
trachea, bridged by the isthmus, with a band of thyroid
tissue running anterior to the trachea. Parathyroid
glands —regulate serum calcium levels
Responsible for the production of two hormones:
thyroid hormone and calcitonin
Calcitonin is secreted by parafollicular C cells and is
involved in calcium homeostasis.
Thyroid follicular cells (thyrocytes) are the major cell
type in the thyroid gland are responsible for the
production and secretion of the thyroid hormones
thyroxine (T4) and triiodothyronine (T3). Organized into
spheres surrounding a central core of fluid called
colloid.
Actions of Thyroid Hormones
 Brain maturation, increased heat production,
increased oxygen consumption, and increased
expression of β- adrenergic receptors.
 T4 - in the cytoplasm is de -iodinated into T3.
-
The most common cause of Hyperthyroidism is an
autoimmune disorder called Grave’s disease.
Thyroid-Stimulating Hormone Test
3 Generations of assays:
First Generation TSH – all the assays are
capable of diagnosing primary hypothyroidism.
Second (TSH Immunometric assays) – can
effectively screen hyperthyroidism.
Third (Chemiluminometric assays) – less likely
give false-negative results, but can accurately
distinguish between euthyroidism and
hyperthyroidism.
 T3 - production of messenger RNA leads to
production of proteins that influence
metabolism and development.
Understanding of the hypothalamic –pituitary –thyroid
axis is essential for correctly interpreting thyroid
function testing.
Hypothyroidism
-
Defined as a low free T4 level with a normal or
high TSH.
One of the most common disorders of the
thyroid gland.
Occurring in 5% to 15% of women over the age
of 65.
RENAL FUNCTION
Glomerular Filtration
•
First part of the nephron and functions to filter
incoming blood.
•
Several factors facilitate filtration:
-high pressure in the glomerular capillaries.
-semipermeable glomerular basement
membrane.
•
Glomerular filtrate - the glomerulus filters out
125 to 130 mL of an essentially protein-free,
cell-free fluid.
•
Glomerular Filtration Rate (GFR) - the volume of
blood filtered per minute
Thyrotoxicosis
-
-
-
A constellation of findings that result when
peripheral tissues respond to an excess of
thyroid hormone.
Can be the result of excessive thyroid hormone
ingestion, leakage of stored thyroid hormone
from storage in the thyroid follicles.
Excessive thyroid gland production of thyroid
hormone.
Proximal Convoluted Tubule
•
Graves' Disease
-
The most common cause of thyrotoxicosis.
An autoimmune disease in which antibodies are
produced that activate the TSHR.
Features of Graves' disease are thyrotoxicosis,
goiter, ophthalmopathy (eye changes
associated with inflammation and infiltration of
periorbital tissue), and dermopathy (skin
changes in the lower extremities that have an
orange peel texture).
•
Next part of the nephron to receive the now
cell-free and essentially protein-free blood.
Function; to return the bulk of each valuable
substance back to the blood circulation.
•
•
Tubular absorption, when the substances move
from the tubular lumen to the peritubular
capillary plasma
Renal Threshold, the plasma concentration
above which the substance appears in urine.
Second function: to secrete products of kidney
tubular cell metabolism.
Loop of Henle
•
The hyperosmolality that develops in the
medulla is continuously maintained by the loop
of Henle.
•
Hairpin-like loop between the proximal tubule
and the distal convoluted tubule.
Ascending limb
•
Sodium and chloride are actively and passively
reabsorbed.
Descending limb
•
•
Highly permeable to water and does not
reabsorb sodium and chloride.
Countercurrent multiplier system
Distal Convoluted Tubule
•
Renin - Initial component of the renin –
angiotensin– aldosterone system.
•
Produced by the juxtaglomerular cells of the
renal medulla.
•
Angiotensin is converted to angiotensin II by
angiotensin-converting enzyme.
Glomerular Diseases
Acute Glomerulonephritis - Histologic
examination shows large, inflamed glomeruli
with a decreased capillary lumen.
Chronic Glomerulonephritis - Lengthy
glomerular inflammation may lead to
glomerular scarring and the eventual loss of
functioning nephrons.
Gradual development of uremia (or azotemia,
excess nitrogen compounds in the blood) may
be the first sign of this process.
Nephrotic Syndrome - Nephrotic syndrome can
be caused by several different diseases that
result in injury and increased permeability of
the glomerular basement membrane. Abnormal
findings, such as massive proteinuria (>3.5 g/d)
and resultant hypoalbuminemia.
•
Much shorter than the proximal tubule
Therapy for Kidney Failure
•
About 95% of the sodium and chloride ions and
90% of water have already been reabsorbed
from the original glomerular filtrate
Dialysis – to remove waste products and excess fluid
from the blood when the kidneys stop working
properly.
•
Function: to affect small adjustments to achieve
electrolyte and acid –base homeostasis.
Transplantation – Body's immune response to the
transplanted organ must be suppressed.
Collecting Duct
•
•
•
•
Final site for either concentrating or diluting
urine.
40 % to 60% of urea is reabsorbed.
Chloride and urea are also reabsorbed here.
Because the collecting ducts in the medulla are
highly permeable to urea.
Kidneys synthesize
Screened for ABO blood group, human leukocyte
antigen compatibility, and preformed HLA antibodies.
URINALYSIS
SPECIMEN COLLECTION
• Morning specimens are preferred
• Clean midstream catch or catheterization
• Clean- dry container with a tight-fitting cover
• Analyzed within 1 hour at room temperature or
refrigerated at 2C to 8C for not more than 8 hours.
PANCREATIC FUNCTION AND GASTROINTESTINAL
FUNCTION
Laboratory Analysis
1. Secretin/CCK Test
A direct determination of the exocrine secretory
capacity of the pancreas.
Test involves intubation of the duodenum without
contamination by gastric fluid.
How the test performed?
Performed after a 6- hour or overnight fast.
Pancreatic secretion is stimulated by intravenously
administered secretin in a dose varying from 2 to 3 U/kg
of body weight, followed by CCK administration.
Pancreatic secretions are collected variously for 30, 60,
or 80 minutes.
Tests of Pancreatic Function
• FECAL FAT ANALYSIS
Derived from four sources:
 unabsorbed ingested lipids
 lipids excreted into the intestine
(predominantly in the bile)
 cells shed into the intestine
 metabolism of intestinal bacteria
• QUALITATIVE SCREENING TEST FOR FECAL FAT
 These tests commonly use fat-soluble stains.
 Sudan III, Sudan IV, Oil Red O, or Nile blue
sulfate which dissolve in and color lipid droplets
• SUDAN STAINING FOR FECAL FAT

Neutral fats (triglycerides) and many other
lipids stain yellow-orange to red with Sudan III
because the dye is much more soluble in lipid
than in water or ethanol. Free fatty acids do not
stain appreciably unless the specimen is heated
in the presence of the stain with 36% acetic
acid.
• QUANTITATIVE FECAL FAT ANALYSIS
 72-hour stool collection (5 days)
 Traditional methods for fecal fat determination
are the gravimetric and titrimetric methods
• GRAVIMETRIC METHOD FOR FECAL FAT
DETERMINATION
 The entire fecal specimen is emulsified with
water. An aliquot is acidified to convert all fatty
acid soaps to free fatty acids, which are then
extracted with other soluble lipids into
petroleum ether and ethanol. After evaporation
of the organic solvents, the lipid residue is
weighed.
• SWEET ELECTROLYTE DETERMINATIONS
 Useful test for the diagnosis of cystic fibrosis.
• SERUM ENZYMES
 Amylase is the serum enzyme most commonly
relied on for detecting pancreatic disease.
 Both amylase and lipase may be significantly
increased in serum in many other conditions
(opiate administration, pancreatic carcinoma,
intestinal infarction, obstruction or perforation,
and pancreatic trauma).
• FECAL ELASTASE
 Performed on random stool samples and has
the advantage of being noninvasive. It has been
shown to be useful in the diagnosis of cystic
fibrosis in children.
GASTROINTESTINAL FUNCTION
Gastric secretion occurs in response to various stimuli:
 Neurogenic impulses from the brain
transmitted by means of the vagal nerves
(responses to the sight, smell, or anticipation of
food).
 Distention of the stomach with food or fluid.
 Contact of protein breakdown products, termed
secretagogues, with the gastric mucosa.
 The hormone gastrin is the most potent
stimulus to gastric secretion.
 Pepsin- refers to a group of relatively weak
proteolytic enzymes.
 Intrinsic factor- most important component of
gastric secretion in terms of body physiology.
-
-
-
Malabsorption of lipids typically results in a
serum concentration of carotenoids lower than
the reference range of 50 to 250 mg/dL.
Caused diminished serum concentrations
because of starvation, dietary idiosyncrasies,
and fever.
The test does not distinguish among the various
etiologies of malabsorption.
Zollinger-Ellison Syndrome
A rare digestive disorder that results in too much gastric
acid. Cause peptic ulcers (stomach and intestine)
Test of Gastric/Intestinal Function
• MEASURING GASTRIC ACID
-
The volume, pH, and titratable acidity and the
calculated acid output of each specimen are
reported.
• PLASMA GASTRIN
-
Invaluable in diagnosing Zollinger- Ellison
syndrome.
• LACTOSE TOLERANCE TEST
-
Used to establish this diagnosis, but the test is
subject to many false-positive and falsenegative
results.
• D-XYLOSE ABSORPTION TEST
-
Use smaller doses of D-xylose to avoid
abdominal cramps, intestinal hypermotility, and
osmotic diarrhea.
• D-XYLOSE TEST
-
The concentration of D-xylose is determined by
heating protein-free supernates of urine and
plasma to convert xylose to furfural.
• SERUM CAROTENOIDS
-
Carotenoids are absorbed in the small intestine
in association with lipids.
Generally speaking, proteins do everything in the living
cell. Proteins are responsible for many different
functions within cells so they are commonly classified
by the function(s) they perform.
Enzymes are proteins that catalyze biochemical
reactions. They are normally found intracellularly, but
are released into the bloodstream as a result of tissue
damage, making enzyme measurements an important
diagnostic tool. Transaminases, dehydrogenases, and
phosphatases are just a few examples of enzyme groups
that are routinely tested in the clinical laboratory to
evaluate possible tissue damage.
Hormones are chemical messenger proteins that
control the action(s) of specific cells or organs.
Hormones directly affect growth and development,
metabolism,sexual function, reproduction, and
behavior. Examples of hormones that are
commonly tested in the clinical laboratory in blood,
urine, or saliva are insulin, testosterone, growth
hormone, follicle-stimulating hormone, and cortisol.
Transport Proteins, many proteins are involved in the
transport of ions, small molecules, or macromolecules,
such as hormones, vitamins, minerals, and lipids, across
a biologic membrane. Examples of commonly measured
transport proteins are hemoglobin, albumin,
ceruloplasmin, haptoglobin, and transferrin.
Immunoglobulins or antibodies are proteins that are
produced by B cells (lymphocytes) in the bone marrow.
Immunoglobulins mediate the humoral immune
response to identify and neutralize foreign antigens.
Examples of immunoglobulins of clinical importance are
IgG, IgM, IgE, and IgA.
Structural Proteins, fibrous proteins provide structure
to many cells and tissues throughout the body, such as
muscle, tendons, and bone matrix. Collagen, elastin,
and keratin are examples of structural proteins.
Storage proteins serve as reservoirs for metal ions and
amino acids so they can be stored without causing harm
and released later. Ferritin is a commonly measured
protein that stores iron for later use in the manufacture
of hemoglobin.
Energy Source, some proteins serve as an energy source
for tissues and muscle. Creatine is one example of an
energy source protein as it helps to supply energy to
cells throughout the body, but is primarily found in
muscle tissue.
Osmotic Force, some proteins function in the
distribution of water throughout the compartments
of the body. Their colloid osmotic force, due to their
size, does not allow proteins to cross the capillary
membranes. As a result, water is absorbed from
the tissue into the venous portion of the capillary.
When the concentration of plasma proteins is
significantly decreased, the concomitant decrease in the
plasma colloidal osmotic (oncotic) pressure results in
increased levels of interstitial fluid and edema. This
often occurs in renal disease when proteins are
inappropriately excreted in urine and plasma protein
concentrations are decreased.
POST EXAMS REVIEWER
1ST-EXAM-LECTURE
1. A Gaussian distribution is usually: bell shaped
2. It is defined as the number of gram equivalent
weights per 1L of solution: Normality
3. It is the percentile expression of the standard
deviation over the mean: Coefficient of
variation
4. A type of photodetector which contains a series
of anodes known as dynodes: Photomultiplier
5. Photomultiplier tube is _____ times more
sensitive than the phototube. 200
6. This converts the transmitted light into an
equivalent amount of electrical energy:
Photodetector
7. Absorptivity depends on the molecular
structure and the way in which the absorbing
molecules react with different energies; The
amount of light absorbed at a particular
wavelength depends on the molecular and ion
types present and may vary with concentration,
pH, or temperature. Both statements are true
8. All of the following choices below are examples
of light source used in Spectrophotometer such
as Deuterium/Mercury Arc, Xenon, and
Tungsten except: He-Ne light
9. It is the wavelength selector or filter; isolates a
portion of the spectrum emitted by the source
and focuses it on the sample: Monochromator
10. This uses one photodetector and a chopper:
Double-beam in time spectrophotometer
11. In a spectrophotometric determination, which
one of the following is the formula for
calculating the absorbance of a solution:
Absorptivity x light path x concentration
12. Beer’s Law: Concentration of the substance is
directly proportional to the amount of light
absorbed or inversely proportional to the log
of the transmitted light.
13. The principle of this instrumentation is
detection of the light energy, scattered of
reflected toward a detector that is not in the
direct path of the transmitted light:
Nephelometer
14. All of the following choices below are examples
of the light source used in nephelometry such
as QuartzHalogen Lamp, Xenon Lamps, and
LASER.
15. In Fluorometry, it is the difference between
maximum wavelength, excitation and emitted
fluorescence: Stokes effect
16. The detector in fluorometer is at right angle to
the excitation light source in order to: Prevent
light interference from the source
17. It is the process in which components of a
mixture are separated by differential
distribution between a mobile phase and
stationary phase: Chromatography
18. Refers to the group of techniques used to
separate complex mixtures on the basis of
different physical interactions between the
individual compounds and stationary phase of
the system: Chromatography
19. It is a technique for measuring concentration of
solute particles that contributes to the osmotic
gradient pressure of the solution: Osmometry
20. The most common energy source in AAS is:
Hallow cathode lamp
21. The type of instrumentation that measure light
emitted by excited atoms, used widely to
determine concentration of sodium, potassium
and lithium: Flame Photometry
22. This measures the light emitted by excited ions,
specifically it determines concentration of: Na,
K or Li: Flame Photometry
23. This is used to quantify stained zone; measures
absorbance of each fraction as gel moves pass a
photometric optical system and displays an
electropherogram on a recorder chart or
computer display in electrophoretic set up:
Densitometer
24. This measures abundant larger particles and
bacterial suspension: Turbidimeter
25. This refers to the migration of charged solutes
or particles of any size in a liquid medium under
the influence of an electrical field:
Electrophoresis
26. This can be used for some qualitative test but
not for routine analyses and reagent
preparation: Type 3 reagent water
27. This is recommended for standardization
techniques: Type 1 reagent water
28. This is used for specific procedures such as
chromatography, atomic absorption,
immunoassays, molecular diagnostics and
standard techniques: Ultrapure Grades
29. This is used only for industrial purposes and
should not be used in the clinical laboratory:
Technical Grade/Commercial Grade
30. This term pertains to molecule that is either
positively or negatively charged: Electrolyte
31. This type of glass material is the most
expensive; fair resistance to chemical attack:
Soft (boron-free) glass
32. This is 6x stronger than borosilicate; hard,
optically pure and resists scratching:
Aluminosilicate
33. This volumetric glassware is used to measure
volume when high degree of accuracy is not
essential: Volumetric flask
34. Visible light has a spectrum of: 400nm-700nm
35. What is the color observed in 500nm-580nm
wavelength: green
36. What is the conversion factor for Blood Urea
Nitrogen: 0.357
37. What is the conversion factor for Uric acid:
0.0595
38. What is the conversion factor of cortisol: 0.0276
39. What is the wavelength of near infrared:
800nm-2500nm
40. What statistical tool can be use to compare the
means of two groups of data: T Test
41. Which of the following statements below is true
about %T: Ratio of the radiant energy
transmitted divided by the radiant energy
incident on the sample
42. Which of the following statements below is
UNTRUE about centrifuge: For its quality
control, checking of timer and speed every 2
months using a stopwatch and tachometer.
43. Which of the following statements below is
UNTRUE about Chemiluminescence: Requires
monochromator
TRUE: - No excitation radiation required
- Reactions are based on: oxidation
reactions of luminol, acridium ester, dioxetanes
44. Which of the following statements below is
UNTRUE about Coefficient of Variations: Index
of accuracy. Its value is directly proportional to
its precision
TRUE: Low values means high precision
45. Which of the following statements below is
untrue about Systeme International d’ Unites:
Several subclassifications exist within the SI
system, one of which is the complex unit.
46. Which of the following statements below is
untrue: Water purified by ion exchange
produces distilled water.
47. Which of the following terms refers to a
measure of dispersion or spread of values
around a central value: Variance
2ND-EXAM-LECTURE
1. A quality control approach that compares the
most recent patient results with their previous
results: Delta check
2. Chain of Custody System must be established to
ensure all persons handled/processed the
specimen are identified; Patient should
remained in same position for 15 minutes
before specimen is collected: 1st statement is
true; 2nd statement is false
3. Glucagon is the primary hormone responsible
for increasing glucose levels; Glucagon is
synthesized by the beta-cells of islets of
Langerhans in the pancreas and released during
stress and fasting states. 1st statement is true;
2nd statement is false
4. In adult, change from lying to upright posture
results in reduction of blood volume about 10%;
Change in posture from lying to standing,
increase secretion of: catecholamine,
aldosterone, angiotensin II, renin and ADH:
Both statements are true
5. In severe DM, the ratio of Beta-hydroxybutyrate
to acetoacetate is 6:1 ; Glucosuria occurs when
plasma glucose levels exceeds 160 mg/dL: 1st
statement is true; 2nd statement is false
6. In the fasting state, the arterial and capillary
blood glucose concentration varies from the
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
venous glucose concentration by approximately
how many mg/dL (mmol/L): 5 mg/dL (0.27
mmol/L) higher
It is the confidence limits in QC: 2SD
Lipemic samples affect some analytical method
to measure serum constituents;
Ultracentrifugation reduce adverse analytical
effects of lipemia: Both statements are true
Monitoring long-term glucose control in
patients with adult onset diabetes mellitus can
best be accomplished by measuring:
Hemoglobin A1c
OGTT requirements include all the following,
except: Carbohydrate intake must be below
150 g/day prior to the test
Preanalytical factors include the following,
except: Results distribution such as wrong
typing and result values
Proficiency Program is part of: External Quality
Control
The conversion of glucose or other hexoses into
lactate or pyruvate is called: Glycolysis
The following are actions of glucagon such as
glycolysis, glycogenolysis, gluconeogenesis, and
glycogenesis.
The following are actions of insulin: Increases
glycogenesis, gglycolysis, & lipo genesis.
Decreases glycogenolysis
The following are factors contributing to
Circadian variation: Posture, food ingestion
stress
The following are the objectives of Quality
Control: To check the stability of the machine.
To check the quality of the reagents. To check
technical error
20.The following is the cause of Hypoglycemia:
Insulinoma. Drugs
The glycates hemoglobin value represents the
integrated values of glucose concentration
during the preceding: 6-8 weeks
The minimum QC requirement for routine
clinical chemistry analyte is: 2 levels of control
assayed in 24 hours
The reference method for glucose: hexokinase
The supernatant fluid after blood has clotted:
Serum
23. Total glycosylated hemoglobin levels in a
hemolysate reflect the: average blood glucose
levels of the past 2-3 months
24. Type 1 Diabetes mellitus is formerly known as:
Insulin-Dependent Diabetes Mellitus
Juvenile Onset Diabetes Mellitus
Ketosis-prone Diabetes
25. Warm the puncture site with a moist towel no
hotter than 42 deg C to increase the blood flow;
For heelstick, blade of the lancet should be <2.4
mm to avoid injury to the infant’s calcareous:
Both statements are true
26. Which of the following are considered sources
of random errors: mislabelling of specimen,
temperature fluctuation, improper mixing of
sample and reagent
27. Which of the following are true of type 1 DM: - - Represent 5-10% of diabetes cases
- Autoimmune destruction
- Ketoacidosis is common
- Most cases are inherited
28. Which of the following choice below is untrue
about pancreas: Located in the curve made by
the ileum
29. Which of the following choices below are the
laboratory findings for Hyperglycemia: - Increased serum and urine osmolality
- Ketones in serum and urine (ketonemia and
ketonuria)
- Decreased blood and urine pH (acidosis)
- Electrolyte imbalance
30. Which of the following choices below is an
example of a monosaccharide: Galactose
31. Which of the following choices below is true
about the effect of Long term fasting and
starvation: Decrease insulin secretion. Increase
lipolysis. Increase blood branched-chain amino
acid
32. Which of the following choices below is true
about the effect of Vegetarianism: Decrease
trace elements (copper, selenium and zinc)
UNTRUE:
- Decrease pH (urine)- due to reduced
intake of precursors of acid metabolites.
- Increase vit. B12
33. Which of the following choices below is untrue
about Hypoglycemia: 50mg/dL: diagnostic
hypoglycaemia value
34. Which of the following choices below is true
about Somatostatin: Produced by the delta
cells. Inhibits the action of insulin. Inhibits the
action of glucagon
35. Which of the following choices below is true
about the effect of Prolonged Bed Rest: Blood
haematocrit is increase by as much as 10%
within 4 days. Nitrogen secretion is increase
urinary excretion by up to 15% after (2) weeks
36. Which of the following choices below pertains
to the Intralaboratory Quality Control: Detects
both random and systematic error
37. Involves the analyses of control samples
together with the patient’s specimen
38. Which of the following is TRUE about
Hyperglycemia: FBS level: >/=126mg/dL. One of
the reasons is having such disorder is
pregnancy
39. Which of the following is true about Type 1
Diabetes mellitus:
- It is due to the presence of Tyrosine
phosphatase IA-2 autoantibodies
- It is due to the presence of Tyrosine
phosphatase IA-2B autoantibodies
- It is due to the presence of Islet cell
autoantibodies
40. Which of the following is true about Type 2
Diabetes mellitus:
- Insulin resistance with an insulin secretory
defect
- Due to metabolic and hormonal changes
UNTRUE:
- It is a type of absolute insulin deficiency
41. Which of the following statements below is true
about Catecholamines:
- Released by the chromaffin cells of the
adrenal medulla
- Promotes glycogenolysis
- Promotes lipolysis
42. Which of the following statements below is true
about Thyroid Hormones: Promotes
glycogenolysis, Promotes gluconeogenesis
43. Which of the following statements below is
untrue about Thyroid Hormones: Promotes
lipolysis
44. Which Westgard rule detects random error: 13S
45. Whipple’s Triad: Low blood glucose
concentration with typical symptoms
alleviated by glucose administration
3RD-EXAM-LECTURE
1. Plays an important role in cell division, the
healing of wounds, stimulation of protein
synthesis, immune function, and the release of
hormones. It is required for the generation of
urea, which is necessary for the removal of toxic
ammonia from the body, and is also required
for the synthesis of creatine, which degrades to
creatinine, a waste product that is cleared from
the body by the kidney: Arginine
2. Cholesterol is, therefore, also an amphipathic
lipid and is found on the surface of lipid layers
along with phospholipids; Cholesterol is
oriented in lipid layers so that the four rings and
the side chain tail are buried in the membrane
in a parallel orientation to the fatty acid acyl
chains on adjacent phospholipid molecules:
Both of statements are true
3. Decreased concentrations of serum albumin
may be caused by the following, except:
Dilution by excess: polydipsia (drinking too
much water) or excess administration of
intravenous fluids
4. Endocrine glands release their products at the
body s surface or into body cavities through
ducts; Exocrine glands are ductless glands that
produce hormones that they release into the
blood or lymph. Both of statements are false
5. Higher levels of exposure have been associated
with demyelinization of peripheral nerves,
which results in a decrease in nerve conduction
velocity: Lead
6. This causes encephalopathy characterized by a
cerebral edema and ischemia: Lead
7. It functions by decreasing thromboxane and
prostaglandin formation through the inhibition
of cyclooxygenase: Aspirin
8. This expresses toxicity by binding to heme iron.
Binding to mitochondrial cytochrome oxidase
causes an uncoupling of oxidative
phosphorylation: Cyanide
9. It is the Formation of violet-colored chelate
between Cu2+ ions and peptide bonds ; Routine
method; requires at least two peptide bonds
and an alkaline medium: Biuret method
10. Methylenedioxymethylamphetamine (MDMA)
is commonly referred to as: Ecstasy, E, or molly,
is a psychoactive drug primarily used for
recreational purposes
11. Prealbumin is so named because it migrates
before albumin in the classic electrophoresis of
serum or plasma proteins; Albumin is the
protein present in highest concentration in the
plasma: Both statements are true
12. The following are examples of Transport
proteins: Hemoglobin. Albumin. Transferrin
13. The following are reasons of decrease
concentration of Urea in the blood: Low protein
intake. Severe vomiting. Diarrhea. Liver
disease. Pregnancy
14. The following statements below are the reasons
of measuring Uric acid in our blood:
- To confirm diagnosis and monitor treatment
of gout
- To prevent uric acid nephropathy during
chemotherapeutic treatment
- To assist in the diagnosis of renal calculi
15. Decreased concentrations of serum albumin
may be caused by the following, except:
- Dilution by excess: polydipsia (drinking too
much water) or excess administration of
intravenous fluid.
16. These are therapeutic drug used for narcolepsy
and attention deficit disorder: Amphetamine &
Methamphetamine
17. What is the end product of the Jaffe reaction:
Red-orange complex
18. Which of the following choices below are
reasons for having Postrenal azotemia: Low
protein intake. Severe liver disease. Severe
vomiting and diarrhea. Pregnancy
19. Which of the following is UNTRUE about
Gonadotropic hormones: In women, the
20.
21.
22.
23.
24.
25.
26.
gonadotropin luteinizing hormone (LH)
stimulates follicle development in the ovaries.
TRUE:
- Hormones regulate the hormonal activity of
the gonads (ovaries and testes)
- In men, LH stimulates testosterone production
by the interstitial cells of the testes.
Which of the following choices below are
reasons for having Prerenal azotemia:
Congestive heart failure. Shock. Hemorrhage.
Dehydration
Which of the following choices below are
reasons for having Renal azotemia: Acute and
Chronic renal failure. Renal disease, including
Glomerular nephritis, tubular necrosis, and
other intrinsic renal disease.
Increased protein catabolism (occurs in stress,
fever, major illness, cortcosteroid therapy and
GI hemorrhage- may increase urea
concentration): High-Protein Diet
Which of the following is true about Oxytocin:
- Released in significant amounts only during
childbirth and in nursing women
- It stimulates powerful contractions of the
uterine muscle during labor, during sexual
relations, and during breastfeeding
- Causes milk ejection (the let-down reflex) in a
nursing woman
Which of the following is true about Ammonia: - Produced in the catabolism of amino acids
and by bacterial metabolism in the lumen of
the intestine
- Some endogenous ammonia results from
anaerobic metabolic reactions that occur in
skeletal muscle during exercise
- Consumed by the parenchymal cells of the
liver in the production of urea
Which of the following is TRUE about
Cannabinoids: Group of psychoactive
compounds found in marijuana
Which of the following is UNTRUE about
Gonadotropic hormones:
In women, the gonadotropin luteinizing
hormone (LH) stimulates follicle development
in the ovaries.
TRUE:
27.
28.
29.
30.
31.
- Hormones regulate the hormonal activity of
the gonads (ovaries and testes)
- In men, LH stimulates testosterone production
by the interstitial cells of the testes.
Which of the following is UNTRUE about LDL:
Primarily contains apo B-100, the main
apolipoprotein, apo E, and apo Cs
TRUE:
- They can infiltrate into the extracellular space
of the vessel wall, where they can be oxidized
and taken up by macrophages through various
scavenger receptors
- LDL is readily taken up by cells via the LDL
receptor in the liver and peripheral cells
Which of the following is true about Parathyroid
Hormone (PTH): Most important regulator of
calcium ion (Ca2, ) homeostasis of the blood
When blood calcium levels drop below a certain
level, the parathyroids release PTH, which
stimulates bone destruction cells (osteoclasts)
to break down bone matrix and release calcium
into the blood: PTH is a hypercalcemic
hormone (that is, it acts to increase blood
levels of calcium)
Which of the following is true about
Triglycerides:
- Each fatty acid in the triglyceride molecule
can potentially be different in structure, thus
producing many possible types of triglyceride
- Triglycerides containing saturated fatty acids,
which do not have bends in their structure
- Contain three fatty acid molecules attached
to one molecule of glycerol by Ester bonds
Which of the following is TRUE about VLDL:
- Produced primarily by the liver and contains
Apo B-100, the main apolipoprotein, Apo E and
Apo cs
- they also reflect light and account for most of
the turbidity observed in fasting
hyperlipidemic plasma specimens, although
they do not form a creamy top layer like
chylomicrons, because they are smaller and
less buoyant
- they are the major carriers of endogenous
(hepatic-derived) triglycerides and transfer
32.
33.
34.
35.
36.
triglycerides from the liver to peripheral tissue
for energy utilization and storage
Which of the following statements below are
true about proteins:
- All biochemical reactions are catalyzed by
enzymes, which contain protein
- The structure of cells and the extracellular
matrix that surrounds all cells is largely made
of the protein group collagens
- Proteins make up antibodies, which are a
major component of the immune system
Which of the following statements below are
true about the Steroid Hormones:
- Diffuse through the plasma membranes of
their target cells enters the nucleus binds to a
specific hormone receptor
- binds to specific sites on the cell’s DNA
- activating certain genes to transcribe
messenger RNA (mRNA)
Which of the following statements below is true
about C-Reactive Protein:
- Synthesized in the liver and is one of the first
acute-phase proteins to rise in response to
inflammatory disease received its name
because it precipitates with the C substance, a
polysaccharide of pneumococci rises sharply
whenever there is tissue necrosis, whether the
damage originates from a pneumococcal
infection or some other source bound to
bacteria and fungi promotes the binding of
complement, which facilitates their uptake by
phagocytes.
Which of the following statements below is true
about Kjeldahl method: Method that focuses
on the measurement of nitrogen content
rather than the protein as a whole
Which of the following statements below is
TRUE about Opiates:
- Class of substances capable of analgesia,
sedation, and anesthesia
- Chronic use leads to tolerance with physical
and psychological dependence
- Acute overdose presents with respiratory
acidosis due to depression of respiratory
centers, myoglobinuria, and possibly an
increase in serum indicators of cardiac damage
37. Which of the following statements below is
untrue about Antidiuretic hormone: ADH
causes the kidneys to reabsorb more water
from the forming urine
TRUE:
- Antidiuretic is a chemical that inhibits or
prevents urine production
- It leads the urine volume decreases and blood
volume increases
- ADH also decreases blood pressure by causing
dilation of the arterioles (small arteries). For
this reason, it is sometimes referred to as
vasopressin
38. Which of the following statements below is true
about Calcitonin:
- Decreases blood calcium levels
- Causes calcium to be deposited in the bones
- It acts antagonistically to parathyroid
hormone
39. Which of the following statements below is
TRUE about Chylomicrons:
- Produced by the intestine, where they are
packaged with absorbed dietary lipids and
apolipoproteins
- Triglycerides and cholesteryl esters in
chylomicrons are rapidly hydrolyzed by lipases
and, within a few hours, are transformed into
chylomicron remnant
- The principal role of chylomicrons is the
delivery of dietary lipids to hepatic and
peripheral cells.
40. Which of the following statements below is
TRUE about Alanine:
- One of the simplest of the amino acids and is
involved in the energy-producing breakdown
of glucose
- Helps in reducing the buildup of toxic
substances that are released into muscle cells
when muscle protein is broken down quickly
to meet energy needs
- Strengthens the immune system through
production of antibodies
41. Which of the following statements below is
TRUE about Electrophoresis:
- Separates proteins on the basis of their
electric charge densities
- Protein, when placed in an electric current,
will move according to their charge density,
which is determined by the pH of a
surrounding buffer
- At a pH lower than the pI, the protein is
negatively charged (AA NH3 +)
- The direction of movement depends on
whether the charge is positive or negative;
cations (positive net charge) migrate to the
cathode (negative terminal), whereas anions
(negative net charge) migrate to the anode
(positive terminal).
42. Which of the following statements below is
untrue about Enzymes:
- Lipid in nature that catalyze chemical
reactions
TRUE:
- Normally found inside cells but are released to
the blood in tissue damage, making enzyme
measurement a very important diagnostic tool
- Examples of groups of enzymes tested in the
clinical laboratory are the transaminases,
dehydrogenases, and phosphatases
43. Which of the following statements below is
TRUE about Growth hormone:
- Its major effects are directed to the growth of
skeletal muscles and long bones of the body,
and thus it plays an important role in
determining final body size.
- It is a protein-sparing and anabolic hormone
that causes amino acids to be built into
proteins and stimulates most target cells to
grow in size and divide.
- It causes fats to be broken down and used for
energy while it spares glucose, helping to
maintain blood sugar homeostasis.
44. Which of the following statements below is
TRUE about Hormones:
- Strictly protein in nature that are chemical
messengers that control the actions of specific
cells or organs.
- It affects growth and development,
metabolism, sexual function, reproduction,
and behavior
- Examples of hormones that are tested in the
clinical laboratory in blood, urine, or saliva are
45.
46.
47.
48.
49.
insulin, testosterone, growth hormone, folliclestimulating hormone, and cortisol
Which of the following statements below is
untrue about Immunoglobulins: Produced by T
lymphocytes
TRUE: Produced by B cell. Produced by Plasma
cells
Which of the following statements below is true
about Lipoprotein X:
- Is an abnormal lipoprotein present in patients
with biliary cirrhosis or cholestasis
- This is present in patients with mutations in
lecithin:cholesterol acyltransferase (LCAT), the
enzyme that esterifies cholesterol
- It is different from other lipoproteins in the
endogenous pathway due to the lack of apo B100
Which of the following statements below is
untrue about Prolactin: Protein hormone
structurally similar to thyroid hormone.
TRUE:
- Its only known target in humans is the breast
- After childbirth, it stimulates and maintains
milk production by the mother s breasts
- Its function in men is not known
Which of the following statements below is
UNTRUE about the formation Creatine:
Synthesized primarily in the liver from
tyrosine, leucine, and guanine
TRUE:
- It is transported to other tissues, such as
muscle, where it is converted to creatine
phosphate, which serves as a high-energy
source
- Creatine phosphate loses phosphoric acid and
creatine loses water to form the cyclic
compound, creatinine, which diffuses into the
plasma and is excreted in the urine
- Creatinine is released into the circulation at a
relatively constant rate that has been shown to
be proportional to an individual’s muscle mass.
Which of the following statements below is
untrue about Urea: It is formed in the liver
from carboxyl groups (– COOH) and free
ammonia generated during protein catabolism
TRUE:
- The NPN compound present in highest
concentration in the blood is urea
- The major excretory product of protein
metabolism
- Since historic assays for urea were based on
the measurement of nitrogen, the term blood
urea nitrogen (BUN) has been used to refer to
urea determination
50. Which of the following statements below is
UNTRUE about Uric acid:
Although it is filtered by the glomerulus and
secreted by the proximal tubules into the
urine, most uric acid is reabsorbed in the distal
tubules and reused.
TRUE:
- Product of catabolism of the purine nucleic
acids
- Relatively insoluble in plasma and, at high
concentrations, can be deposited in the joints
and tissue, causing painful inflammation.
51. α1-Antichymotrypsin inhibits the activity of the
enzymes cathepsin G, pancreatic elastase, mast
cell chymase, and chymotrypsin by cleaving
them into a different shape (conformation);
Haptoglobin is considered an acute-phase
protein that is elevated in many inflammatory
diseases, such as ulcerative colitis, acute
rheumatic disease, heart attack, and severe
infection: Both statements are true