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Write a 1,000-word term paper on a current topic in biology - Stem-cell research Stem Cell Research “Science has presented us with a hope called stem cell research, which may provide our scientists with answers that have so long been beyond our grasp”. - Nancy Reagan “As a right-to-life Senator, I believe that a critical part of a pro-life, pro-family philosophy is helping the living…The purpose of [stem cell] research is to save life, not terminate it.” - U.S. Senator Orrin Hatch (R-UT) Introduction: Among the various tremendous discoveries and advancements in the field of health and remedies, still there are equally astounding health issues prevailing as serious and chronic diseases. The most fascinating field of biology today, where advancing knowledge had been implicated in order to generate damaged cells in the body of adult organisms is the “Stem Cell Research”. This research is channelized towards a specialized cell holding distinctive characteristics are the stem cells. Basically stem cells are diverse group of unspecialized multipotent cells capable of extraordinary renewing and replacing themselves through cell division as well as capable of developing into other cell types like heart cell, kidney cell, liver cell etc with special functions. The stem cells getting differentiated into other cell types are of embryonic in origin. Stem cells can very well get differentiated into brain, blood, tissue or muscle cells. Stem cell research knowledge has given us knowledge to repair and replace the damaged cells by substituting the cells for diseases like diabetes, chronic heart failure, parkinson’s disease, spinal cord injuries, stroke etc., Stem cell research has got both pros and cons and an existing hot topic of debate. Pros/Advantages of Stem Cells: Soruce: http://www.sumanasinc.com/ Stem cell debate’s most recent incarnation centers on both the pros and cons of its research. The stem cell enunciates pluripotent (ability to produce different types of cells of the body), totipotent (cells capable of developing and dividing into a complete organism) and multipotent (differentiated cells capable of developing other tissues) property and can be obtained from different sources. Depending on the source the stem cells are of the following types, Embryonic stem cells (pluripotent) – harvested from fertilized embryo with inner cell mass termed blastocyst Fetal stem cells (multipotent) – gathered from gonads of aborted fetuses made up of germline tissues Umbilical cord stem cells (multipotent/pluripotent) – derived from blood in the umbilical cord Placental derived stem cells (multipotent/pluripotent) – originated from the placenta Adult stem cells (multipotent) – isolated from the adult tissue Research done by many stem cell researchers for cell-based therapies showed the preferential choice of usage of embryonic stem cells than the other types of stem cells (Kogler et al., 2004). Stem cell research has stretched its hands to combat a variety of diseases like parkinson’s diseases. Newman and Bakay (2008) addressed the advancements in the stem cell research and experimentation in relation to parkinson’s disease. Hou and Hong (2008) reviewed various stem cells taking into account the progression and prospects of neural, mesenchymal and embryonic stem cells for the treatment of neurodegenerative diseases like Parkinson's disease, Alzheimer's disease, Huntington' disease and Amyotrophic lateral sclerosis/Lou Gehrig's disease. The diagnostic and therapeutic implications stem cells over specific cancer cell markers on colon, breast, liver, pancreas and prostrate tissues showed the intriguing way for new therapeutic and advanced opportunities (Klonisch et al., 2008). A detailed study done by Guo et al., 2006 showed the characteristics of cancer stem cells and its role in cancer development as well the ways to bring them into clinical research. A review by Yang and Chang (2008) focused the current status and issues in the cancer stem cell study as well examined the differences and similarities between somatic stem cell and cancer cells. A new avenue has been opened in the area of stem cell research for treating cardiovascular diseases like myocardial infarction, chronic coronary artery disease, stroke etc. A randomized trial was conducted in which autologous stem cells or progenitor stem cells are tested for its therapeutic efficacy over cardiovascular diseases (Brehm et al., 2008). Bernardo and Docherty (2008) discuss the application of embryonic stem cells over metabolic diseases. Various studies has been carried out by many researchers in the field of diabetes and stem cells serve as a multipotent cell to treat the ailments related to diabetes as well organ regeneration and development (Best et al., 2008; Sordi et al., 2008; Rochi et al., 2007). Stem cell research excitement is primarily due to its ability to combat the ailments posed by spinal cord injuries, birth defects as well to replace or repair the amputated/damaged organs and also to reduce the risk of transplantation (Louro and Pearse, 2008; Coutts and Keirstead, 2007; Hematti, 2008) . Stem cells are found to provide economic and social benefits for community as well as for individuals in the society. The stem cells do not develop autoimmunity as it belongs to their own cells and are found to be immortal. The stem cells can be easily extracted, flexible to handle and are pluri, toti and multipotent (http://www.allaboutpopularissues.org/). Ethical issues play a major role in all many experiments and in regard with adult, neural and cord blood stem cells no moral and ethical issues is being followed (http://www.stemcelltherapies.biz/). Cons/Disadvantages of stem cells: Stem cell research began early in the year 1960 and the controversy seems to be only recent. All types of stem cells can only be found at certain stage like embryonic stem cells can only be found in the blastocyst stage, multipotent stem cells in the umbilical cord blood of the fetus as well adult tissues. Embryonic stem cells require culling of embryos which sustains moral intuitions and ethical issues. Scientists concentrating over stem cell research ends up with the hope to relieve human sufferings with the end of a life of an embryo (http://www.stemcelltherapies.biz/). Even though the embryonic stem cells for experiments are basically nurtured and fertilized in the laboratory, ethically persons who believe in conceptions would fall always the destruction to be unacceptable and immoral. The embryonic stem cell research stands as such a controversial issue currently standing away distinctively forms all other stem cell research issues. The embryonic stem cells which are being used for various treatments belong to alternative non-embryonic sources (www.stemcells.nih.gov). Similarly fetal stem cells require destruction of fetus of particular age, while the umbilical cord, placental and adult stem cells holds very less frequency of stem cells. Embryonic stem cells has again got its own pros and cons, even it is the more preferred cell among the other types of stem cells. Embryonic stem cells are found to be more versatile than the other stem cell types; due to its versatility it becomes unusable sometimes for therapy. The differentiation has to be complete before using it in patients otherwise it would end up migrating throughout the body to produce tumors. Tissue compatability is again another major issue faced by embryonic stem cells (Bjorklund et al., 2002; Carson et al., 2006; Bjorklund et al., 2002). There is no evidence for clinical treatment from human embryonic stem cells as well in the animal models the rate of success was found to be dismally low. Pure stem cell culture is difficult to obtain in the laboratory. Transdifferentiation of the stem cells remains unanswered. Stem cells are difficult to maintain and remains a s a problem of immune rejection. Stem cells holds problem with genomic instability and incompatibility (Bjorklund et al., 2002). Conclusion: The precise mechanism underlying the adult stem cells potency to cure diseases and repair damaged cells and tissues are even still under investigation and the progression is overwhelming. Many rely upon Cell based therapies as it shows ultimate cure for many incurable and irreparable diseases. The only field which entails even after holding so much of controversies would be the stem cell research field whose upgradation grows along with the controversies. Newer technologies are still pursuing stem cell research as it provides cheaper and provides less trouble during usage especially while using in patient-directed therapies. Stem cell research will ultimately end up in a great bloom in the field of medicine is of no doubt. References Soruce: http://www.sumanasinc.com/ Kogler G et al. 2004. A ew Human somatic stem cell from placental cord blood with intrinsic pluripotent differentiation potential. Journal of Experimental Medicine. 200 : 123-135. Newman MB, Bakay RA. Therapeutic potentials of human embryonic stem cells in Parkinson's disease. Neurotherapeutics. 2008 Apr;5(2):237-51. Hou L, Hong T. Stem cells and neurodegenerative diseases. Sci China C Life Sci. 2008 Apr;51(4):287-94. Epub 2008 Mar 27. Klonisch T, Wiechec E, Hombach-Klonisch S, Ande SR, Wesselborg S, Schulze-Osthoff K, Los M. Cancer stem cell markers in common cancers - therapeutic implications. Trends Mol Med. 2008 Sep 3. [Epub ahead of print]. Guo W, Lasky JL 3rd, Wu H. Cancer stem cells. Pediatr Res. 2006 Apr;59(4 Pt 2):59R- 64R. Yang YM, Chang JW. Current status and issues in cancer stem cell study. Cancer Invest. 2008 Aug;26(7):741-55. Brehm M, Darrelmann E, Strauer BE. [Stem cell therapy in acute myocardial infarction.] Internist (Berl). 2008 Sep;49(9):1068-78. Bernardo AS, Docherty K. Stem cells and metabolic diseases. Biochem Soc Trans. 2008 Jun;36(Pt 3):363-5. Best M, Carroll M, Hanley NA, Piper Hanley K. Embryonic stem cells to beta-cells by understanding pancreas development. Mol Cell Endocrinol. 2008 Jun 25;288(1-2):86-94. Epub 2008 Mar 27. Sordi V, Bertuzzi F, Piemonti L. Diabetes mellitus: an opportunity for therapy with stem cells? Regen Med. 2008 May;3(3):377-97. Roche E, Ensenat-Waser R, Vicente-Salar N, Santana A, Zenke M, Reig JA. Insulin- producing cells from embryonic stem cells experimental considerations. Methods Mol Biol. 2007;407:295-309. Louro J, Pearse DD. Stem and progenitor cell therapies: recent progress for spinal cord injury repair. Neurol Res. 2008 Feb;30(1):5-16. Coutts M, Keirstead HS. Stem cells for the treatment of spinal cord injury. Exp Neurol. 2008 Feb;209(2):368-77. Epub 2007 Sep 12. Hematti P. Role of mesenchymal stromal cells in solid organ transplantation. Transplant Rev (Orlando). 2008 Jul 23. http://www.allaboutpopularissues.org/ http://www.stemcelltherapies.biz/ http://www.stemcells.nih.gov http://www.stemcelltherapies.biz/ Bjorklund, L. M., R. Sanchez-Pernaute, et al. 2002. Embryonic stem cells develop into functional dopaminergic neurons after transplantation in a Parkinson rat model. Proceedings of the National Academy of Sciences 99: 2344-2349. Carson, C. T., S. Aigner and F. H. Gage. 2006. Stem cells: the good, bad and barely in control. Nature Medicine 12: 1237-1238. Bjorklund, L. M., R. Sanchez-Pernaute, et al. 2002 "Embryonic stem cells develop into functional dopaminergic neurons after transplantation in a Parkinson rat model." Proceedings of the National Academy of Sciences 99: 2344-2349.
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