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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.

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Brehm M, Darrelmann E, Strauer BE. [Stem cell therapy in acute myocardial infarction.]

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Bernardo AS, Docherty K. Stem cells and metabolic diseases. Biochem Soc Trans. 2008

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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

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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.

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Hematti P. Role of mesenchymal stromal cells in solid organ transplantation. Transplant

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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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