Stem cells work Stem cells What are stem cells: Stem cells are special human cells that are able to develop into many different cell types. This can range from muscle cells to brain cells. In some cases, they can also fix damaged tissues. What is meant by the term undifferentiated: Tissues that do not have specialized ("mature") structures or functions. What problems can the division of stem cells cause: Mutations have been observed in stem cells cultured for a number of generations, and some mutated stem cells have been observed to behave like cancer cells. Stem cell potency Potency – potency is a measure of drug activity expressed in terms of the amount required to produce an effect of given intensity. Totipotent – the term totipotent: “capable of developing into a complete organism” or “differentiating into any of its cells or tissues” Pluripotent – capable of giving rise to several different cell types. Multipotent – can develop into more than one cell type, but are more limited than pluripotent cells. Differentiation What is the benefit of being a multicellular organism: increase in size without its limitations. They can have longer lifespans as they can continue living when individual cells die. Multicellularity also permits increasing complexity by allowing differentiation of cell types within one organism. Explain how blood cells are examples of this: Multiple cells work together to create tissues; tissues work together to create organs. In this way, complex functions are distributed by different types of cells. As an example, red blood cells are used to balance the PH of blood and transport oxygen throughout the body. Replacement of blood cells Why do blood cells need to be produced from stem cells: Once a blood stem cell divides, its daughter cells take various differentiation routes to produce different types of specialized blood cells. Specialized blood cells do not live very long, so the body needs to replace them continuously. Blood stem cells do this job. Where are these stem cells located? Blood stem cells are found in the peripheral blood and the bone marrow. How long do neutrophils live? How many do stem cells produce an hour: neutrophils have a very short life-span in blood circulation, estimated to be less than 24 h. 4166666666 per hour. Sources of animal stem cells What are the two main sources of animal stem cells? Stem cells originate from two main sources: adult body tissues and embryos. What potency are they at: Totipotent How are they recovered: The most common way to harvest stem cells involves temporarily removing blood from the body, separating out the stem cells, and then returning the blood to the body. Sources of plant stem cells Where are stem cells found in plants: at the tips of shoots and roots in groups called meristems. What potency are they at: Pluripotent or Multipotent What are their normal functions in plants: Stem cells function as a source of new cells to grow or replace specialised tissues. To perform this function, these cells must divide to renew themselves, while some of their descendants eventually differentiate to build up new tissues. Uses of stem cells Outline the diseases and treatment stem cells already can provide: People who might benefit from stem cell therapies include those with spinal cord injuries, type 1 diabetes, Parkinson's disease, amyotrophic lateral sclerosis, Alzheimer's disease, heart disease, stroke, burns, cancer and osteoarthritis. Stem cell ethics What are the main objections to using stem cells: The use of stem cells in medical research and therapies has been the subject of ethical and moral debates due to several reasons. One of the main objections to the use of stem cells is related to moral and ethical concerns. Some people believe that the use of embryonic stem cells, which are derived from human embryos, is unethical because it involves the destruction of potential human life. This argument is based on the idea that human life begins at conception, and therefore, the use of embryonic stem cells is equivalent to taking a human life. Some religious groups also oppose the use of stem cells, particularly embryonic stem cells, because they believe that human life begins at conception. Another objection to the use of stem cells is related to safety concerns. The use of stem cells in medical therapies is still in its early stages, and there are concerns about the safety and potential long-term side effects of stem cell treatments. Stem cell therapies are complex procedures that involve manipulating cells and tissues in the body, which can lead to unintended consequences. There are also concerns about the potential for stem cells to form tumours or to differentiate into unwanted cell types. Additionally, stem cell research is a complex field, and there are still many scientific and technical challenges to overcome before stem cell therapies can be fully developed and widely used. Despite these concerns, many scientists and medical professionals believe that the potential benefits of stem cell research and therapies outweigh the ethical and moral concerns. What are the issues with using stem cells from umbilical cords: Using stem cells from umbilical cords is generally considered safe and effective. Umbilical cord stem cells are a rich source of hematopoietic and mesenchymal stem cells, which have the potential to differentiate into a wide range of cell types. These cells can be used in a variety of medical applications, including treating blood disorders, immune system disorders, and some types of cancer. However, there are some potential issues to consider when using stem cells from umbilical cords. One issue is that there may not be enough cells collected from the umbilical cord to be used for certain treatments. For example, in the case of an adult who requires a large number of stem cells, the number of stem cells in a single umbilical cord may not be sufficient. This can limit the usefulness of the cells for some applications. Another issue is that the cells may not be a perfect match for the patient receiving the treatment. While stem cells from umbilical cords are considered "less immunogenic" than cells from other sources, there is still a risk of rejection or other complications if the cells are not a close enough match. Despite these issues, stem cells from umbilical cords remain a promising source of cells for a wide range of medical applications. Ongoing research is focused on improving the collection, processing, and storage of umbilical cord stem cells to ensure their safety and efficacy. Additionally, new techniques are being developed to expand the number of cells that can be derived from a single cord and to improve the matching of cells to patients, which could further enhance the utility of umbilical cord stem cells in regenerative medicine.
