- Stem cell treatments
medical researchers believe that stem cell treatments have the potential to change the face of human disease and alleviate suffering. A number of stem celltreatments exist, although most are still experimental and/or costly, with the notable exception of bone marrow transplantation. Medical researchers anticipate one day being able to use technologies derived from adult and embryonic stem cell research to treat cancer, Type 1 diabetes mellitus, spinal cord injuries, and muscledamage, as well as a number of other diseases and impairments.
Several very promising treatments of serious diseases have already been attempted, using adult stem cells. The advantage of adult stem cells over embryonic stem cells is that there are no rejection issues, because the stem cells are normally taken from the patient.
There still exists a great deal of social and scientific uncertainty surrounding embryonic stem cell research. This will, most likely, only be overcome through years of intensive research and by gaining the acceptance of the public.
For over 30 years, bone marrow, and more recently, umbilical cord blood stem cells have been used to treat
cancerpatients with conditions such as leukemiaand lymphoma. During chemotherapy, most growing cells are killed by the cytotoxicagents. These agents not only kill the leukemia or neoplastic cells, but also the haematopoietic stem cells within the bone marrow. It is this unfortunate side effect of the chemotherapy that the Stem Cell Transplant attempts to reverse; the donor's healthy bone marrow reintroduces functional stem cells to replace those lost in the treatment. In all current Stem Cell treatments obtaining Stem Cells from a matched Donor is preferable to using the patients own. If (always as a last resort and usually because no matched Donor can be found) it is deemed necessary for the patients own stem cells to be used and the patient has not stored their own collection of stem cells (umbilical cord blood), bone marrow samples must therefore be removed before chemotherapy, and are re-injected afterwards.Fact|date=October 2007
Stroke and traumatic brain injury lead to cell death, characterized by a loss of neurons and oligodendrocytes within the brain. Healthy adult brains contain neural stem cells, these divide and act to maintain general stem cell numbers or become
progenitor cells. In healthy adult animals, progenitor cells migrate within the brain and function primarily to maintain neuron populations for olfaction (the sense of smell). Interestingly, in pregnancy and after injury, this system appears to be regulated by growth factors and can increase the rate at which new brain matter is formed. In the case of brain injury, although the reparative process appears to initiate, substantial recovery is rarely observed in adults, suggesting a lack of robustness.
Recently, results from research conducted in rats subjected to
stroke, suggested that administration of drugs to increase the stem cell division rate and direct the survival and differentiation of newly formed cells could be successful. In the study referenced below, biological drugs were administered after stroke to activate two key steps in the reparative process. Findings from this study seem to support a new strategy for the treatment of stroke using a simple elegant approach, aimed at directing recovery from stroke by potentially protecting and/or regenerating new tissue. The authors found that, within weeks, recovery of brain structure is accompanied by recovery of lost limb function suggesting the potential for development of a new class of stroke therapy or brain injury therapy in humans.Fact|date=October 2007
Research injecting neural (adult) stem cells into the brains of dogs has shown to be be very successful in treating cancerous
tumors. With traditional techniques brain canceris almost impossible to treat because it spreads so rapidly. Researchers at the Harvard Medical Schoolinduced intracranial tumours in rodents. Then, they injected human neural stem cells. Within days the cells had migrated into the cancerous area and produced "cytosine deaminase", an enzyme that converts a non-toxic pro-drug into a chemotheraputic agent. As a result, the injected substance was able to reduce tumor mass by 81 percent. The stem cells neither differentiated nor turned tumorigenic. [http://www.mult-sclerosis.org/news/Dec2000/StemCellDebatePartII.html] Some researchers believe that the key to finding a cure for cancer is to inhibit cancer stem cells, where the cancer tumor originates. Currently, cancer treatments are designed to kill all cancer cells, but through this method, researchers would be able to develop drugs to specifically target these stem cells. [ [http://www.wired.com/medtech/health/news/2004/08/64549 "Cancer Stem Cells Hint at Cure" at wired.com] ]
pinal cord injury
A team of Korean researchers reported on
November 25, 2004, that they had transplanted multipotent adult stem cells from an umbilical cord blood to a patient suffering from a spinal cord injury and that she can now walk on her own, without difficulty. The patient had not been able stand up for roughly 19 years. The team was co-headed by researchers at Chosun University, Seoul National Universityand the [http://www.seoulcord.co.kr/bin/main.asp Seoul Cord Blood Bank] (SCB). For the unprecedented clinical test, the scientists isolated adult stem cellsfrom umbilical cord blood and then injected them into the damaged part of the spinal cord. [ [http://times.hankooki.com/lpage/200411/kt2004112617575710440.htm Page Error : 찾으시는 Page의 URL이 잘못되었거나 없습니다 ] ] [http://www.cordblood.com/cord_blood_news/stem_cell_news/a_paralyzed.asp] [ [http://www.connected.telegraph.co.uk/news/main.jhtml?xml=/news/2004/11/30/wcells30.xml Umbilical cord cells 'allow paralysed woman to walk' - Telegraph ] ] [ [http://www.wpherald.com/storyview.php?StoryID=20041127-121143-6745r] Dead link|date=March 2008]
The Korean researchers have followed up on their original work. The original treatment was conducted in November 2004. On
April 18, 2005, the researchers announced that they will be conducting a second treatment on the woman. [ [http://times.hankooki.com/lpage/tech/200504/kt2005041818233411800.htm Page Error : 찾으시는 Page의 URL이 잘못되었거나 없습니다 ] ] The researchers have followed up with a case study write-up on their work. It is located in the journal [http://taylorandfrancis.metapress.com/(4ozazs45mhxqid20qghurzfi)/app/home/contribution.asp?referrer=parent&backto=issue,8,9;journal,2,41;linkingpublicationresults,1:107693,1 "Cytotherapy"] . [ [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16162459&query_hl=1 A 37-year-old spinal cord-injured female patient, ... [Cytotherapy. 2005 - PubMed Result ] ]
According to the
October 7, 2005issue of " The Week", University of Californiaresearchers injected human embryonic stem cells into paralyzed mice, which resulted in the mice regaining the ability to move and walk four months later. The researchers discovered upon dissecting the mice that the stem cells regenerated not only the neurons, but also the cells of the myelin sheath, a layer of cells which insulates neural impulses and speeds them up, facilitating communication with the brain (damage to which is often the cause of neurological injury in humans). [http://img227.imageshack.us/img227/7954/stemcellbreakthru052wl.jpg] .
In January 2005, researchers at the
University of Wisconsin-Madisondifferentiated human blastocyst stem cells into neural stem cells, then into the beginnings of motor neurons, and finally into spinal motor neuron cells, the cell type that, in the human body, transmits messages from the brainto the spinal cord. The newly generated motor neurons exhibited electrical activity, the signature action of neurons. Lead researcher [http://www.waisman.wisc.edu/faculty/zhang.html Su-Chun Zhang] described the process as "you need to teach the blastocyst stem cells to change step by step, where each step has different conditions and a strict window of time."
Transforming blastocyst stem cells into motor neurons had eluded researchers for decades. The next step will be to test if the newly generated neurons can communicate with other cells when transplanted into a living animal; the first test will be in chicken embryos. Su-Chun said their trial-and-error study helped them learn how motor neuron cells, which are key to the
nervous system, develop in the first place. The new cells could be used to treat diseases like Lou Gehrig's disease, muscular dystrophy, and spinal cord injuries.
Several clinical trials targeting heart disease have shown that adult stem cell therapy is safe and effective. Adult stem cell therapy for heart disease was commercially available on at least five continents at the last count (2007).
Haematopoiesis (blood cell formation)
In December 2004, a team of researchers led by Dr.
Luc Douayat the University of Parisdeveloped a method to produce large numbers of red blood cells. The Nature Biotechnologypaper, entitled [http://www.nature.com/nbt/journal/v23/n1/abs/nbt1047.html "Ex vivo" generation of fully mature human red blood cells] , describes the process: precursor red blood cells, called hematopoietic stem cells, are grown together with stromal cells, creating an environment that mimics the conditions of bone marrow, the natural site of red blood cell growth. Erythropoietin, a growth factor, is added, coaxing the stem cells to complete terminal differentiation into red blood cells.
Further research into this technique should have potential benefits to gene therapy, blood transfusion, and topical medicine.
Hairfollicles also contain stem cells, and some researchers predict research on these follicle stem cells may lead to successes in treating baldnessthrough "hair multiplication", also known as "hair cloning", as early as 2007. This treatment is expected to work through taking stem cells from existing follicles, multiplying them in cultures, and implanting the new follicles into the scalp. Later treatments may be able to simply signal follicle stem cells to give off chemical signals to nearby follicle cells which have shrunk during the agingprocess, which in turn respond to these signals by regenerating and once again making healthy hair. [http://my.webmd.com/content/article/96/103836.htm?z=3734_00000_1000_qd_01 "Hair Cloning Nears Reality as Baldness Cure"] ( WebMDNovember 2004)
In 2004, scientists at
King's College Londondiscovered a way to cultivate a complete tooth in mice [ [http://www.telegraph.co.uk/connected/main.jhtml?view=DETAILS&grid=P8&targetRule=10&xml=%2Fconnected%2F2004%2F02%2F17%2Fecntee15.xml Dental advance will let adults grow new teeth - Telegraph ] ] and were able to grow them stand-alone in the laboratory. Researchers are confident that this technology can be used to grow live teeth in human patients.
In theory, stem cells taken from the patient could be coaxed in the lab into turning into a tooth bud which, when implanted in the gums, will give rise to a new tooth, which would be expected to take two months to grow. [ [http://whyfiles.org/shorties/147tooth/ Teeth from scratch ] ] It will fuse with the jawbone and release chemicals that encourage nerves and blood vessels to connect with it. The process is similar to what happens when humans grow their original adult teeth. It's estimated that it may take until 2009 before the technology is widely available to the general public, but the genetic research scientist behind the technique, Professor Paul Sharpe of King's College, estimates the method could be ready to test on patients by 2007. [ [http://www.sciencedaily.com/releases/2004/05/040504063535.htm Grow Your Own Teeth ] ] His startup company,
Odontis, fully expects to offer tooth replacement therapy by year 2015-2018 [http://www.odontis.co.uk/faq.php]
In 2005, Cryopraxis a stem cell bank in Brazil, collected baby tooth stem cells and harvested different types of differentiated cell types including neurons. This technology may one day make baby teeth a good source of stem cells.
In the next three years,
Paul Sharpehopes to identify more-accessible stem cells that may be able to form not only teeth, but also--and more importantly--roots. [ [http://www.technologyreview.com/Biotech/18216/ Technology Review] ]
There has been success in regrowing cochlea hair cells with the use of stem cells. [ [http://www.newscientist.com/article.ns?id=dn7003 Gene therapy is first deafness 'cure' - health - 14 February 2005 - New Scientist ] ]
Blindness and vision impairment
Since 2003, researchers have successfully transplanted retinal stem cells into damaged eyes to restore vision. Using
embryonic stem cells, scientists are able to grow a thin sheet of totipotent stem cells in the laboratory. When these sheets are transplanted over the damaged retina, the stem cells stimulate renewed repair, eventually restoring vision. [ [http://www.medicalnewstoday.com/medicalnews.php?newsid=15535 Fetal tissue restores lost sight ] ] The latest such development was in June 2005, when researchers at the Queen Victoria Hospitalof Sussex, Englandwere able to restore the sight of forty patients using the same technique. The group, led by Dr. Sheraz Daya, was able to successfully use adult stem cells obtained from the patient, a relative, or even a cadaver. Further rounds of trials are ongoing. [ [http://news.bbc.co.uk/1/hi/england/southern_counties/4495419.stm BBC NEWS | England | Southern Counties | Stem cells used to restore vision ] ]
In April 2005, doctors in the UK transplanted
cornealstem cells from an organ donor to the corneaof Deborah Catlyn, a woman who was blinded in one eye when an acid was thrown in her eye at a nightclub. The cornea, which is the transparent window of the eye, is a particularly suitable site for transplants. In fact, the first successful human transplant was carried out in 1905 on a cornea by Dr. Eduard Zirm. The recipient was Alois Gloger, a labourer who had been blinded in an accident. The cornea has the remarkable property that it does not contain any blood vessels, making it relatively easy to transplant. The majority of corneal transplants carried out today are due to a degenerative disease called keratoconuswhich causes vision impairment and has no known cure even after corneal transplant. It is hoped that stem cell research will one day provide a cure to such debilitating corneal disorders.
The University Hospital of New Jersey claims a success rate growing the new cells from transplanted stem cells varies from 25 percent to 70 percent. [ [http://www.theuniversityhospital.com/healthlink/archives/articles/limbalstem.html ] The University Hospital of New Jersey, 2002]
ALS (Lou Gehrig's Disease)
April 4, 2001edition of JAMA (Vol. 285, 1691-1693), [http://www.cellmedicine.com/als.asp] Drs. Gearhart and Kerr of Johns Hopkins University used stem cells to cure rats of an ALS-like disease. The rats were injected with a virus to kill the spinal cord motor nerves related to leg movement. Dr. Gearhart and Dr. Kerr then injected the spinal cords of the rats with stem cells. These migrated to the sites of injury where they were able to regenerate the dead nerve cells restoring the rats which were once again able to walk.
Graft vs. host disease and Crohn's disease
Phase III clinical trials expected to end in second-quarter 2008 were conducted by
Osiris Therapeuticsusing their in-development product Prochymal, derived from adult bone marrow. The target disorders of this therapeutic are graft-versus-host diseaseand Crohn's disease. [cite news | author=Querida Anderson | title= Osiris Trumpets Its Adult Stem Cell Product
url=http://www.genengnews.com/articles/chitem.aspx?aid=2508 | work=
Genetic Engineering & Biotechnology News
Mary Ann Liebert, Inc.| page=13 | date=2008-06-15 | accessdate=2008-07-06 | quote=(subtitle) Procymal is being developed in many indications, GvHD being the most advanced ]
Stem cell use in animals
Horses have been treated with stem cells since 2003, mainly to treat injuries to the tendons, ligaments, and joints of
sport horses or racehorses. Fat is harvested from the tail head and processed, and an animal may receive treatment within two days after the sample is taken. Injuries that may be treated include Degenerative Joint Disease, tendonitis, suspensory ligament desmitis, Osteochondrosis, fractures, and sub-chonral bone cysts. Currently, research is also being performed on stem cell application in laminitisand COPD. [ [http://www.vet-stem.com/index.php?subPageN=&mainPageN=Home&UprPageN=vetstem Vet-Stem | Dog Stem Cell Horse & Cat | Arthritis | Tendon Ligament Joint | San Diego | Equine | Canine | VetCell ] ]
A recent double-blinded, placebo controlled study showed the effectiveness of adipose-derived stem cells in dogs with osteoarthritis, specifically, bilateral hip dysplasia ( [http://www.veterinarytherapeutics.com/vtxv8n4a1 Black et al, Veterinary Therapeutics, 8 (4), 2007] ). [ [http://www.veterinarytherapeutics.com/vtxv8n4a1 Black et al, Veterinary Therapeutics, 8 (4), 2007] ]
There is currently research being performed on chronic hepatitis and canine muscular dystrophy. This work, which has been successfully translated from mice to dogs could provide a means of treating muscular dystrophy in humans.
There is wide spread controversy over the use of embryonic stem cells. This controversy is over the technique used to create new embryonic
stem cell lines, which often requires the destruction of the blastocyst.
Opposition to the use of human embryonic stem cells in research is based on moral or religious objections. Others point to the success already being achieved with stem cell therapy that does not result in the destruction of a developing human being, such as the use of cord blood cells to treat spinal cord injury paralysis or recent research in turning skin fibroblasts into embryonic stem cell-like cells, and argue that research should be aimed in those avenues with a proven safety and efficacy.
ome scientists see shift in stem cell hopes
It was reported in the "New York Times" (
14 August 2006), by Nicholas Wade, that some scientists see a shift in stem cell hopes. Several mentioned that the main role of stem cells was in research. Many no longer see cell therapy as the first goal of the research, parting company with those whose near-term expectations for cell therapy remain high. [http://www.nytimes.com/2006/08/14/washington/14stem.html Some Scientists See Shift in Stem Cell Hopes - New York Times ] ]
tem Cell Research and Treatment in China
Stem cell research and treatment is actively practiced in China. State funded [http://www.beikebiotech.com Chinese Companies] based in the Shenzhen Hi-Tech Industrial Zone [http://www.stemcellschina.com claim] to treat the symptoms of numerous disorders with adult stem cell therapy. Hospitals throughout eastern China provide numerous therapies to patients in coordination with the stem cell providers. These companies' therapies are currently focused on the treatment of neurodegenerative and cardiovascular disorders.
Chinese stem cell research has not been restricted by the ethical dilemmas and legislative gridlock surrounding the procurement and use of human embryonic stem cells in other developed nations such as the US, UK, and Australia. These issues have also hampered the development of adult stem cell research and therapy, as unrelated a cellular origin as they may have. Most stem cell therapies provided in China utilize umbilical cord stem cells (drawn from Wharton's jelly) donated from live births. The stem cells are then expanded in centralized blood banks. Cells are delivered to patients via IV, spinal epidural, subcutaneous injection or transplantation.
While anecdotal evidence of secondary adult stem cell activity has existed for several decades alongside bone marrow transplant therapies, "off-label" uses for stem cells are strictly forbidden in the USA. There, protocols for proposed treatments are described and enforced by the Food and Drug Administration (FDA). In America, the period between laboratory experimentation and clinical treatment can be decades long. Researchers actively treating patients with experimental therapies outside of carefully monitored clinical trials can be subject to harsh disciplinary action by their institutions. The Chinese [http://english.gov.cn/2005-10/09/content_75326.htm Ministry of Health] has already accepted the use of stem cell therapy for many disorders. After years of practice, stem cell therapy is no longer considered new or dangerous in China and is regularly used by the Chinese in the treatment of the degenerative effects of Multiple sclerosis and Parkinson's disease. International "Medical Tourists" are among the thousands of patients treated in China every year for disorders the patients' home country's medical professionals offer no treatment.
*Fiona Murray Ph.D., Debora Spar Ph.D. [http://content.nejm.org/cgi/content/full/355/12/1191 "Bit Player Or Powerhouse? China And Stem-Cell Research"] , "New England Journal Of Medicine"
September 21, 2006Accessed July 30, 2007
*Clive Cookson [http://www.sciam.com/article.cfm?articleID=00092B38-2E51-12BC-ADB783414B7F014C "Generous Staffing And Permissive Laws Aid Asia's Largest Stem Cell Effort"] , "Scientific American"
June 27, 2005Accessed July 30, 2007
* [http://www.stemcellcordblood.net Stem Cell and Cord Blood information database]
* [http://www.stemcellschina.com Stem Cell News] : Treatment details and patient histories in China
* [http://www.abc.net.au/news/stories/2008/02/02/2152899.htm Spare Parts, grown and installed] : Finnish cancer patient gets replacement parts grown from his own stem cells.
* [http://www.regenecell.com/article-autism.htm Potential of Stem Cell Treatment in Autism]
* [http://www.regenecell.com/article-multiple-sclerosis-status.htm Status of Stem Cell Therapy for Multiple Sclerosis]
* [http://www.regenecell.com/article-stem-cell-therapy-for-stroke.htm Stem Cell Therapy for Stroke]
Wikimedia Foundation. 2010.
Look at other dictionaries:
Stem cell controversy — The stem cell controversy is the ethical debate primarily concerning the creation, treatment, and destruction of human embryos incident to research involving embryonic stem cells. Not all stem cell research involves the creation, use, or… … Wikipedia
Stem cell — Mouse embryonic st … Wikipedia
Stem cell line — A stem cell line is a family of constantly dividing cells, the product of a single parent group of stem cells. They are obtained from human or animal tissues and can replicate for long periods of time in vitro ( within glass ; or, commonly, in… … Wikipedia
Stem cell research policy — Stem cell research policy, a controversial topic, varies significantly throughout the world. There are overlapping jurisdictions of international organizations, nations, and states or provinces. Some government policies determine what is allowed… … Wikipedia
stem cell — Cell Biol. a cell that upon division replaces its own numbers and also gives rise to cells that differentiate further into one or more specialized types, as various B cells and T cells. [1880 85] * * * ▪ biology Introduction an undifferentiated… … Universalium
Stem Cell Research Enhancement Act — was the name of two similar bills that both passed through the United States House of Representatives and Senate, but were both vetoed by President George W. Bush and were not enacted into law. Despite their names, the proposed statutes remained… … Wikipedia
Adult stem cell — Adult stem cells are undifferentiated cells found throughout the body after embryonic development that divide to replenish dying cells and regenerate damaged tissues. Also known as somatic (from Greek Σωματικóς, of the body ) stem cells, they can … Wikipedia
Embryonic stem cell — Embryonic stem cells (ES cells) are stem cells derived from the inner cell mass of an early stage embryo known as a blastocyst. Human embryos reach the blastocyst stage 4 5 days post fertilization, at which time they consist of 50 150 cells.… … Wikipedia
Hematopoietic stem cell — HSC=Hematopoietic stem cell, Progenitor=Progenitor cell, L blast=Lymphoblast, Lymphocyte, Mo blast=Monoblast, Monocyte, Myeloblast … Wikipedia
Mesenchymal stem cell — showing typical ultrastructural morphology. Latin cellula mesenchymatica precursoria Code TH H2 … Wikipedia