Topics (select one)
a) Genetically modified organisms (GMOs). What is the purpose genetic engineering of crop plants and domestic animals? Briefly explain how GMOs are created. What foods in your supermarket contain GMOs? Are foods that contain GMOs safe for human consumption? What types of regulations exist for these foods? Clearly explain your reasoning for each answer. The following website from FDA regarding GMO regulation may be helpful: http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm352067.htm
b) Stem cells. Your friend had a spinal cord injury after a bad car accident. The medical team has decided that he is a good candidate for a clinical trial using stem cell therapy. Your friend has not had a biology course since high school, so you decide to write him a letter sharing your knowledge of stem cells. Include in your letter a description of the biology of stem cells and how these cells are unique from other cells. Contrast the different types of stem cells, including pros and cons of each. Explain how stems cells are can be used to treat diseases and injury, with special focus on spinal cord injuries. Conclude with your own opinion. The following website from NIH regarding stem cell research will be very helpful: http://stemcells.nih.gov/index.asp.
c) Fracking (hydraulic fracturing) and tar sands (oil sands). With society’s dependence on nonrenewable fossil fuels, the oil & gas industry is turning to the use of hydraulic fracturing and tar (oil) sands to extract natural gas and oil respectively. A friend asks you “What’s all this controversy in the news about fracking and tar sands?” Briefly explain to your friend how hydraulic fracturing and tar (oil) sands are used to obtain these fossil fuels. Then, in more detail, describe the environmental problems that may result from these processes and why they are controversial. Issues that may be addressed involves, but are not limited to, water, air and soil pollution, effects on human health, effects on other species and natural ecosystems. Finally, give your opinions on possible solutions to these environmental problems, with your reasoning backed by the references that you studied. The following websites from EPA may be helpful: http://www2.epa.gov/hydraulicfracturing
Stem cells are a type of unspecialized cells that multiply themselves for an indefinite time under certain conditions eventually growing into mature specialized cell types within the body. This is called stem cell proliferation. Stem cells serve as the body’s repair mechanism because they reproduce to replenish other damaged cells. When stem cells proliferate, they either remain as stem cells or turn into other types of specialized cells such as brain cells, muscle cells or red blood cells.
Stem cells are distinguished from other types of cells because they possess these two significant characteristics. The first is that they are unspecialized cells that proliferate themselves over time by cell division. Secondly, they can be manipulated under certain undefined conditions to proliferate into specialized cells.
Types of Stem Cells
There are essentially two types of stem cells; Embryonic and adult stem cells. Embryonic stem cells are found in a 4 to 7 day old embryo and they are able to grow into any type of specialized cell within the body. Adult stem cells on the other hand are found in the grown body tissues. They are stem cells that only proliferate into mature specialized cells in the specific tissue. For instance, a heart muscle adult stem cell can only proliferate to give rise to specialized heart muscle cells.
The main difference between the two is the type of cells they become after proliferation. Embryonic stem cells are known proliferate into any cell type while adult stem cells are restricted since they can only proliferate into the parent tissue cell type. In laboratory research, scientists are able to grow embryonic stem cells in large numbers. However, adult stem cells are not found in large numbers within mature body tissues and scientists have not been able to develop and proliferate them in large quantities. This laboratory proliferation is particularly important for the advancement of stem cell replacement therapies.
Stem cells from an adult grown in culture have a therapeutic advantage of favourable reintroduction back into the patient. The patient’s own cells are fully compatible with the host and when reintroduced back, the immune system does not reject them. However the possibility of embryonic stem cells grown in culture being rejected by the host’s immune system is very high after reintroduction.
The significance of stem cell research
Stem cells in humans can be applied in various ways for both basic and clinical research. Notwithstanding the many technical and unknown obstacles, the continued stem cell research promises the imminent realisation of stem cell gains especially in physiology. The research on human embryonic stem cells aids in the understanding of the complicated yet coordinated occurrences through the early human development. Scientists are trying to distinguish what causes stem cells to divide into differentiated cells.
Nearly all dire non-communicable conditions such as cancer, diabetes, heart disease and birth defects are primarily caused by unnatural cell division and development. With the advancement of these studies, scientists will eventually be able to better understand the genetic and molecular causes of abnormal cell division. This will eventually lead to the development of stem cell therapy for these conditions.
Human stem cells could also in future be useful in the active testing of new medicines. By testing for the reaction and safety of the drugs on mature cells proliferated from embryonic stem cells, pharmacists will be able to precisely control and monitor the effects of the drugs on different cell types.
Stem cell therapy is possibly the most significant potential application of human stem cell research. Currently organ and tissue transplanting remains the most feasible treatment of destroyed or malfunctioning organs. However, the demand of donated organs is far much more than the supply. Stem cell therapy offers a possible natural repair of the organs and tissues. This procedure involves the extraction of either embryonic or adult stem cells, these cells are then grown in culture by genetically influencing the differentiation of the stem cell and turning them into the desired mature health differentiated cells. Lastly, the cells can then be reintroduced back into the body to repair the malfunctioning tissues.
Stem cell therapy therefore offers the hope of artificially generating healthy replacing cells and tissues to treat diseases such as cancer, stroke, diabetes, heart disease and spinal cord injury. Spinal cord injury is the damage to the white and gray matter which transmits both sensory and motor signals from the brain to the organs and vice versa. There is increased optimism in the treatment of spinal cord injuries due to the recent advancements of stem cell proliferation of neuroprotective and regenerative cells. These gains have been pre-clinically proven through studies conducted on rodents with spinal cord injuries.
The cell therapy trials for the treatment of spinal cord injuries have been conclusively conducted in lab mice patients and have shown a high degree of safety and positive response. These gains have given a huge endorsement for the commencement of human trials. However before testing it on human patients, there is need for the clinical researchers to conclusively proliferate sufficient quantities of differentiated tissue, successfully transplant and functionally integrate it into the host organ without causing any present or future health concerns.
Department of Health and Human Services. (2001). Stem Cells: Scientific Progress and Future Research Directions. Retrived from http://stemcells.nih.gov/info/2001report/pages/2001report.aspx
Syed, A. P., Sandeep, K. V., Tenneti, V. M., Thiriveedi, N. R. & Aleem, A. K. (2012). Potential role of stem cells in severe spinal cord injury: Current perspectives and clinical data. Stem Cells and Cloning: Advances and Applications. Dove press journal