http___metro-portal.hr_maticne-stanice-su-put-do-izljecenja-teskih-bolesti-danasnjice_4388_1.xml
2.1 3.1 3.2 5.1 5.2 6.1 6.2 6.3 8.1 9.1 9.2 10.1 10.2 12.1 13.1 13.2 15.1 15.2 18.1 18.2 18.3 20.1 21.1 22.1 25.1 26.1 26.2 26.3 27.1 29.1 29.2 29.3 32.1 33.1 35.1 35.2 36.1 37.1 39.1 40.1 42.1 43.1 43.2 44.1 45.1 45.2 45.3 46.1 46.2 48.1 48.2 48.3 49.1 49.2 49.3 49.4 50.1 51.1 52.1 52.2 52.3 52.4 53.1 56.1 56.2 57.1 59.1 60.1 61.1 61.2 61.3 62.1 62.2 62.3 62.4 62.5 63.1 65.1 66.1 66.2 67.1 69.1 69.2 70.1 70.2 71.1 73.1 73.2 73.3 73.4 74.1 74.2 74.3 74.4 74.5 74.6 75.1 76.1 76.2 78.1 78.2 78.3 79.1 79.2 79.3 80.1 80.2 81.1 84.1 84.2 85.1 86.1 86.2 87.1 89.1 90.1 90.2 91.1 93.1 93.2 94.1 96.1 96.2 96.3 96.4 97.1 97.2 97.3 97.4 98.1 100.1 101.1 101.2 101.3 101.4 101.5 102.1 104.1 104.2 104.3 104.4 105.1 107.1 108.1 108.2 108.3 108.4 109.1 109.2 110.1 113.1 114.1 114.2 115.1 117.1 118.1 118.2 119.1 122.1 123.1 124.1 126.1 127.1
"A UK and Canadian team have manipulated human skin cells to act like embryonic stem cells without using viruses – making them safer for use in humans. "Study leader Dr. Keisuke Kaji, from the Medical Research Council Centre for Regenerative Medicine at the University of Edinburgh, said nobody, including himself, had thought it was really possible. 'It is a step towards the practical use of reprogrammed cells in medicine, perhaps even eliminating the need for human embryos as a source of stem cells,' he said." "A groundbreaking medical treatment that could dramatically enhance the body's ability to repair itself has been developed by a team of British researchers. The therapy, which makes the body release a flood of stem cells into the bloodstream, is designed to heal serious tissue damage caused by heart attacks and even repair broken bones…. "A possible danger with some other stem cell therapies in the pipeline is their use of embryonic stem cells. Because these can turn into any type of tissue, there is a risk they could grow into cancer cells when injected into patients. [This] treatment uses stem cells that can only grow into blood vessels, bone and cartilage, so the risk of causing cancer is removed." "Controversial research into the use of 'hybrid' human-animal embryos to make stem cells is in danger of stalling because of a lack of funding, British scientists claim…. "Since the furore broke… scientists have developed a cheap and powerful new technique in which adult skin cells are reprogrammed to create cells that are almost identical to stem cells. Researchers have already used the technique to make so-called induced pluripotent stem (iPS) cells for patients with diabetes, muscular dystrophy and Down's syndrome…. [Quoting Harry Moore, head of reproductive biology at Sheffield University] 'What has happened is the field has moved on. You could argue that iPS cells are a more important area than hybrids now.' "A dose of their own stem cells 'reset' the malfunctioning immune system of patients with early-stage multiple sclerosis and, for the first time, reversed their disability…. 'This is the first study to actually show reversal of disability,' said Richard Burt, an associate professor in the division of immunotherapy at Northwestern, and the lead author of the study published yesterday in the British journal, the Lancet Neurology. 'Some people had complete disappearance of all symptoms.' "A new study suggests that adult bone marrow stem cells can be used in the construction of artificial skin. The findings mark an advancement in wound healing and may be used to pioneer a method of organ reconstruction." "The reality is that the bulk of today's stem-cell research relies on adult stem cells taken from bone marrow, blood, skeletal muscles, body fat and umbilical cord blood. Scientists have even managed to coax adult skin cells to mimic the versatility of embryonic stem cells, which can grow virtually any cell or tissue in the human body. Unlike embryonic stem cells, though, these adult stem cells are being tested in humans right now, with very real possibilities to change the way various diseases are treated in the next five to 10 years." "For the first time, scientists at Children's Hospital of Pittsburgh of UPMC have discovered a unique population of adult stem cells derived from human muscle that could be used to treat muscle injuries and diseases such as heart attack and muscular dystrophy…. "Because this is an autologous transplant, meaning from the patient to himself, there is not the risk of rejection you would have if you took the stem cells from another source… "Myoendothelial cells also showed no propensity to form tumors, a concern with other stem cell therapies." "An Ecuadorian stem cell expert said on September 24 that transplants of autologous adult bone marrow stem cells restored some function in spinal cord injury (SCI) patients who have been paralyzed for an average of four years, some up to 22 years…. "Of the 25 patients who provided more than three months and up to 14 months follow up: 15 gained the ability to stand up, 10 could walk on the parallels with braces, seven could walk without braces and five could walk with crutches. Three patients recovered full bladder control, and 10 patients regained some form of sexual function. No adverse events or abnormal reactions to implantation were observed…. 'By implanting an adult's own bone marrow stem cells, we've seen significant improvements in the quality of life for those who suffer from spinal cord injuries,' … said Francisco Silva, executive vice president of research and development for PrimeCell Therapeutics." "In recent years, scientists have… discovered that red bone marrow is… the body's Swiss Army repair kit. It contains a traveling laboratory of cells that can heal the liver, heart, kidneys, leg arteries, pancreas, and even ovaries and the brain. Up to 40 percent of the liver can be regrown from stem cells found in bone marrow, researchers at New York University School of Medicine, Yale University School of Medicine and Sloan-Kettering Cancer Center found." "The results of a study published in the April issue of Stem Cells and Development suggest that human stem cells derived from bone marrow are predisposed to develop into a variety of nerve cell types, supporting the promise of developing stem cell-based therapies to treat neurodegenerative disorders such as Parkinson's disease and multiple sclerosis…. "When transplanted into the central nervous system, [these cells] will develop into a variety of functional neural cell types, making them a potent resource for cell-based therapy." "A team of Texas and British researchers says it has produced large amounts of embryoniclike stem cells from umbilical cord blood, potentially ending the ethical debate affecting stem-cell research -- the need to kill human embryos. The international researchers said the cells -- called cord-blood-derived-embryoniclike stem cells, or CBEs -- have the ability to turn into any kind of body tissue, like embryonic stem cells do, and can be mass-produced using technology derived from NASA.... "Scientists believe the ability to replicate tissue could lead to the development of ways to replace organs as well as treat life-threatening diseases such as diabetes, Alzheimer's and Parkinson's, which have been the focus of stem-cell research." -- J. Price, "Advance made in stem-cell debate," The Washington Times, August 20, 2005, www.washingtontimes.com/national/20050820-122747-2417r.htm "Various studies that have been conducted around the world, including a limited number performed in the United States, have suggested that when patients with heart failure receive stem cells taken from their bone marrow, their hearts show signs of improved function and recovery." -- "Stem Cells With Heart Bypass Surgery Trial To Begin At University Of Pittsburgh," ScienceDaily, August 25, 2005, www.sciencedaily.com/releases/2005/08/050825070117.htm "Researchers in Boston have isolated a kind of cell from human bone marrow that they say has all the medical potential of human embryonic stem cells.... "Tufts University researchers used specialized cell-sorting machines to pluck the peculiar cells from samples of bone marrow obtained from different donors. Tests suggested the cells are capable of morphing into many, and perhaps all, of the various kinds of cells that make up the human body. "When a batch of the newly identified marrow cells were injected into the hearts of rats that had experienced heart attacks, some of the cells turned into new heart muscle while others became new blood vessels to support the ailing hearts. "'I think embryonic stem cells are going to fade in the rearview mirror of adult stem cells,' said Douglas W. Losordo, the Tufts cardiologist who left the effort.... Bone marrow, he said, 'is like a repair kit. Nature provided us with these tools to repair organ damage.'" -Rick Weiss, "Marrow Has Cells Like Stem Cells, Tests Show," Washington Post, Feburary 2, 2005, p. A3, at www.washingtonpost.com/wp-dyn/articles/A55369-2005Feb1.html . "[Erica] Nader, 26, of Farmington Hills, Mich., was the first American to travel to Portugal, in March 2003, for experimental sugery for spinal cord injury. She was injured in July 2001 in an auto accident... She was paralyzed from the top of her arms down. "In the procedure...a team of doctors opened Nader's spinal cord to clear out any scar tissue.... Then, using a long tube, they took a sample of olfactory mucosal cells from the ridge of her nose.... These cells are among the body's richest supply of adult stem cells and are capable of becoming any type of cell, depending on where they are implanted. In this case, these adult stem cells were to take on the job of neurons, or nerve cells, once implanted in the spinal cord at the site of an injury. "And after three years, magnetic imaging resonance tests show that the cells indeed promote the development of new blood cells and synapses, or connections between nerve cells, says Dr. Carlos Lima, chief of the Lisbon team. "Dr. Pratas Vital, one of two neurosurgeons on the team, calls the transplanted cells spinal cord autografts, a term that indicates the cells come from a person's own body, not fetal or embryonic stem cells. "[Erica] is much stronger and much more capable of lifting her arms, bending her knees on a slanted exercise board and standing erect. Once, she was paralyzed from her biceps down. Now, she can push herself off an exercise ball, do arm lifts and help raise herself off a floor mat. In the past six weeks, she's started to walk in leg braces with a walker or on a treadmill." -Patricia Anstett, "Paraplegic improving after stem-cell implant," The Indianapolis Star, January 16, 2005, at www.indystar.com/articles/5/209449-5235-047.html. "[E]vidence from three different labs – the University of Minnesota, the Robert Wood Johnson Medical School in New Jersey, and Argonne National Laboratory outside Chicago – have found three different ASCs [adult stem cells] that may be completely plastic. As the team leader at the Robert Wood Johnson School, Ira Black, told me, 'In aggregate, our study and various others do support the idea that one [adult stem cell] can give rise to all types of tissue.' -Michael Fumento, "The Adult Answer," National Review Online, December 20, 2004, at www.nationalreview.com/comment/fumento200412200902.asp. "Scientists have transplanted adult stem cells from the bone marrow of rats into the brains of rat embryos and found that thousands of the cells survive into adulthood, raising the possibility that someday developmental abnormalities could be prevented or treated in the womb. "Dr. Ira Black, chairman of the department of neuroscience at the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, said the cells took on the properties of brain cells, migrating to specific regions and taking up characteristics of neighboring cells. "Black and his colleagues used a specific type of bone marrow cell called a stromal cell, taken from the leg bones of adult rats. 'We see this potentially as an appropriate treatment for prenatal disease, mental retardation and congenital conditions,' Black said. The hope is that a patient's own bone barrow might someday be the source for replacing brain cells lost to illness and brain trauma, experts say, eliminating the need to use human embryonic stem cells. "In a separate study, Dr. Alexander Storch of the University of Ulm, Germany, recently took bone marrow and stromal cells from six healthy people and converted the cells into immature neural stem cells. ... 'A single cell culture could grow all major brain cell types,' said Storch, who used specific growth factors to help them differentiate. Storch is now transplanting the cells into mice with multiple sclerosis, Parkinson's disease and stroke symptoms. In the stroke study, the labeled adult stromal cells migrated to the area surrounding the stroke damage, he said. They had all of the chemical, electrical and functional properties of brain cells." -Jamie Talan, "Stem cell transplant a success," Newsday, May 12, 2004, at http://www.mult-sclerosis.org/news/May2004/SuccessfulRatStemCellTransplant.html. "'Cord blood stem cells have the same capacity to cure disease as do embryonic stem cells, as they can become any cell in the body...,' said Dr. William Schmidt, Jr., an oncologist with the Charleston Cancer Center in N. Charleston, SC. "'The use of umbilical cord blood stem cells in the treatment of disease is one of the most prominent advancements in medicine today. Developments in this field will revolutionize medicine and disease treatment,' said Dr. [Roger] Markwald [Professor and Chair of the Department of Cell Biology and Anatomy at the Medical University of South Carolina]." -Press Release, "CureSource Issues Statement on Umbilical Cord Blood Stem Cells vs. Embryonic Stem Cells," May 12, 2004, at http://home.businesswire.com/portal/site/altavista/index.jsp?ndmViewId=news_view&newsId=20040512005909&newsLang=en. "California scientists have found that neural stem cells can target and track deadly brain tumor cells. The discovery by researchers at Cedars-Sinai's Maxine Dunitz Neurosurgical Institute in Los Angeles means that neural stem cells may someday be effective 'delivery systems' to transport cancer-killing gene and immune products. "'We have previously demonstrated the uncanny ability of neural stem cells to seek out and destroy satellites of tumor cells in the brain,' said John S. Yu, senior author of the study and co-director of the Comprehensive Brain Tumor Program a Cedars-Sinai. With this knowledge, we hope to expedite the translation of this powerful and novel strategy for the clinical benefit of patients with brain tumors.'" -Press release, "Neural stem cells may help fight cancer," May 5, 2004, at http://www.nlm.nih.gov/medlineplus/news/fullstory_17570.html. "'We're not trying to change the [adult stem] cells in any way before we put them in the body. These are very early precursor cells. They have the potential to become almost anything, and they adapt quickly once they're inside,' said [Tulane University Center for Gene Therapy research professor Dr. Brian] Butcher. Tests on rats with damaged spines have shown that cell growth occurs in the spine [after adult stem cell injection] and allows the animals to walk again. "Using adult stem cells sidesteps some of the legal and ethical issues involved in using fetal...or embryonic stem cells.... And there may be other benefits as well. 'We're not against stem-cell research of any kind,' said Butcher. 'But we think there are advantages to using adult stem cells. For example, with embryonic stem cells, a significant number become cancer cells, so the cure could be worse than the disease. And they can be very difficult to grow, while adult stem cells are very easy to grow.' "But perhaps the biggest advantage to adult stem cells is that they sidestep immunological concerns because the cells used to treat a patient come from his or her own body." -Heather Heilman, "Great Transformations," The Tulanian, Spring 2004, at http://www2.tulane.edu/article_news_details.cfm? ArticleID=5155. "Had a major heart attack? In the not-too-distant future, doctors may be able to use stem cells to regenerate damaged heart muscle. And here's the exciting part: They can do it using stem cells that aren't extracted from human embryos. "[G]iven the controversy over harvesting cells from embryos, doctors have been exploring other possibilities. The payoff: A team from the University of Texas M.D. Anderson Cancer Center in Houston recently repaired heart muscles in animals by injecting them with stem cells extracted from human blood. It's the stem-cell equivalent of Columbus reaching America: Not only would cells harvested from one's own body eliminate the risk that they would be rejected, but obtaining them would be a simple, painless proposition. "'This work gives us a way to get the cells that's as easy as giving a blood sample,' says Edward Yeh, M.D., lead author of the study. The real mind boggler is what the stem cells might mean to the 1.2 million Americans who suffer heart attacks each year." -Special Report, "Good news about bad things that happen to your parents," USA Weekend magazine, March 5-7, 2004, p. 6, at www.usaweekend.com/04_issues/040307/040307aging.html#heart. "Scientists in Canada have turned adult skin cells into the building blocks of brain cells --opening the way for their use in new therapies for such incurable diseases. The discovery, by a team at the University of Toronto, is particularly exciting as it promises to provide a readily accessible and ethically neutral source of neural stem cells -- the precursors of nerve and brain tissue. "While other groups have managed to create these cells before, they have generally required the use of adult stem cells from bone marrow, which are difficult and painful to extract, or embryonic stem cells, which require the destruction of a human embryo. "If the Toronto technique is perfected for clinical use it would allow neural stem cells to be made from a patient's skin, ensuring a perfect genetic match that would not be rejected by the body. The cells would then be transplanted into the brains of people with neurological disorders, to replace, for example, the specialized dopamine neurons that are lost in Parkinson's disease." -Oliver Wright, "Patients' Own Skin Cells Turned into Potential Alzheimer's Treatment," The Times (London), December 10, 2003, Home News, p. 8. "Massachusetts General Hospital researchers have harnessed newly discovered cells from an unexpected source, the spleen, to cure juvenile diabetes in mice, a surprising breakthrough that could soon be tested in local patients and open a new chapter in diabetes research... "'This shows there might be a whole new type of therapy that we haven't tapped into,' said Dr. Denise Faustman, MGH immunology lab director and lead author of the new study, which appears today in the journal Science. 'We've figured out how to regrow an adult organ'." Mishra, "Juvenile diabetes cured in lab mice," The Boston Globe, November 14, 2003, p. "There is now an emerging recognition that the adult mammalian brain, including that of primates and humans, harbours stem cell populations suggesting the existence of a previously unrecognised neural plasticity to the mature CNS [central nervous system], and thereby raising the possibility of promoting endogenous neural reconstruction... Since large numbers of stem cells can be generated efficiently in culture, they may obviate some of the technical and ethical limitations associated with the use of fresh (primary) embryonic neural tissue in current transplantation strategies." Ostenfeld and C. Svendsen, "Recent advances in stem cell neurobiology," Advances and Technical Standards in Neurosurgery, vol. "Stem cells in our bone marrow usually develop into blood cells, replenishing our blood system. However, in states of emergency, the destiny of some of these stem cells may change: They can become virtually any type of cell – liver cells, muscle cells, nerve cells – responding to the body's needs. Prof. Tsvee Lapidot and Dr. Orit Kollet of the Weizmann Institute's Immunology Department have found how the liver, when damaged, sends a cry for help to these stem cells. 'When the liver becomes damaged, it signals to stem cells in the bone marrow, which rush to it and help in its repair – as liver cells,' says Lapidot... "The findings could lead to new insights into organ repair and transplants, especially liver-related ones. They may also uncover a whole new stock of stem cells that can under certain conditions become liver cells. Until a few years ago only embryonic stem cells were thought to possess such capabilities. Understanding how stem cells in the bone marrow turn into liver cells could one day be a great boon to liver repair as well as an alternative to the use of embryonic stem cells." -"Weizmann Institute scientists find that stem cells in the bone marrow become liver cells," EurakAlert, August 11, 2003, at www.eurekalert.org/pub_releases/2003-08/wi-wis_1081103.php. I.S. Abuljadayel, Chief Scientific Officer of Tri-Stem Inc., on his study published in the July 2003 Current Medical Research and Opinion on producing pluripotent stem cells from adult blood cells: "This new technology offers a viable option for the generation of large numbers of pluripotent stem cells. These are likely to have many clinical and research applications. The source material is blood, the most accessible tissue in our body which can be extracted by simple venipuncture or aphaeresis. The procedure raises no ethical concerns and removes the need to resort to embryos or aborted fetuses. The technology is also cost-effective, donor-friendly producing relatively large quantities of stem cells within a short time, which could eventually save patient lives and shorten patient waiting lists." -"Stem cell-like plasticity induced in mature mononuclear cells," Reuters Health, July 7, 2003. "This is an example of promising experimental therapies involving stem cells from bone marrow. Until just a few years ago, conventional wisdom held that only embryonic stem cells could turn into any cell in the body. But that thinking began to change as studies showed that stem cells from bone marrow could become heart, muscle, nerve, or liver cells. Now, the results of clinical trials conducted in Britain, Germany and Brazil show that heart patients injected with their own bone marrow cells benefit from the treatment." Touchette,"Bone Marrow Stem Cells Heal the Heart," Genome News Network, May 2, 2003, at www.genomenewsnetwork.org/articles/05_03/sc_heart.shtml "Stem cells from bone marrow can transform into insulin-producing cells, scientists have shown, suggesting a future cure for diabetes... "Transplants of pancreatic cells have been tried between people, but the supplies are restricted and recipients have to take strong anti-rejection medication. Embryonic stem cells have also been converted into insulin-producing cells, but also produce immune-rejection, in addition to ethical concerns. But taking bone marrow cells from a patient, developing them into beta cells and then reimplanting them would have none of these difficulties. Also, much of the technology for bone marrow transplantation is already well developed, says study leader Mehboob Hussain, at the New York University School of Medicine. "'I am absolutely excited by the potential applications of our findings,' he said. 'In our body, there is an additional, easily available source of cells that are capable of becoming insulin-producing cells.'" Bhattacharya, "Bone marrow experiments suggest diabetes cure," NewScientist.com News Service, March 17, 2003, at www.newscientist.com/news/news.jsp?id=ns99993508. "The use of human embryonic stem cells has been confronted with major obstacles because of bio-ethical and political issues involved obtaining them, as well as the suggestion that embryonic stem cells may lack appropriate developmental instructions, making them potentially less feasible for engrafting into adult tissue... "As compared to embryonic stem cells, adult derived stem cells are endowed with additional developmental instructions and may be better suited for therapeutic purposes. According to [Dr. Shahin Rafii of Cornell University Medical College], 'We are approaching a day when a patient's own stem cells can be induced to divide and develop into tissue that can replace that which is diseased or destroyed, making overcrowded organ transplant lists and rejection of foreign tissues a thing of the past'." -"Mechanism For Regulation Of Adult Stem Cells Found," UniSci - Daily University Science News, May 31, 2002, at http://unisci.com/stories/20022/0531021.htm On the versatility of adult hematopoietic (blood-producing) stem cells, HSCs: "[R]ecent studies have suggested that a subpopulation of HSCs may have the ability to contribute to diverse cell types such as hepatocytes, myocytes, and neuronal cells, especially following induced tissue damage... These surprising findings contradict the dogma that adult stem cells are developmentally restricted." Bunting and R. Hawley, "The tao of hematopoietic stem cells: toward a unified theory of tissue regeneration," Scientific World Journal, April 10, 2002, p. 983. Commenting on a study by researchers at New York University, Yale and Johns Hopkins: "'There is a cell in the bone marrow that can serve as the stem cell for most, if not all, of the organs in the body,' says Neil Theise, M.D., Associate Professor of Pathology at NYU School of Medicine... '(t)his study provides the strongest evidence yet that the adult body harbors stem cells that are as flexible as embryonic stem cells'." -"Researchers Discover the Ultimate Adult Stem Cell," ScienceDaily Magazine, May 4, 2001, at www.sciencedaily.com/releases/2001/05/010504082859.htm "Umbilical cords discarded after birth may offer a vast new source of repair material for fixing brains damaged by strokes and other ills, free of the ethical concerns surrounding the use of fetal tissue, researchers said Sunday." -"Umbilical cords could repair brains," Associated Press, February 19, 2001, at www.intelihealth.com/IH/ihtIH/WSIHW000/333/7228/311894.html
1.1 2.1 3.1 4.1 4.2 5.1 6.1 6.2 6.3 6.4 6.5 6.6 6.7 7.1 8.1 8.2 8.3 8.4 9.1 9.2 9.3 10.1 10.2 10.3 11.1 11.2 12.1 13.1 14.1 14.2 14.3 15.1 15.2 15.3 15.4 16.1 17.1 17.2 17.3 18.1 18.2 19.1 20.1 21.1 21.2 22.1 23.1 24.1 25.1 26.1 27.1
Matične stanice su put do izlječenja teških bolesti današnjice Kako na najbolji način koristiti matične stanice iz pupkovine djeteta Zahvaljujući brzom napretku regenerativne medicine, šećerna bolest tip I, Parkinsonova bolest, ozljede leđne moždine ili infarkt srca u skoroj će budućnosti predstavljati manju prijetnju po zdravlje i život čovjeka. U prvom planu ove grane medicine je transplantacija matičnih stanica u bolešću ili ozljedom oštećene organe. Iako matične stanice već 30 godina koristimo u liječenju tumorskih bolesti krvi (leukemije), ili prilikom transplantacije kože kod opsežnih opekotina, u novijoj povijesti medicine ova je tema postala predmetom mnogih polemika. Što su matične stanice? Svaka stanica u našem tijelu sadrži sve gene koji su potrebni za razvoj cijelog ljudskog bića zato što su sve stanice nastale dijeljenjem prve stanice dobivene spajanjem jajne stanice i spermija. Na putu od prve stanice do cijelog organizma stanice se moraju specijalizirati zbog kompleksnosti zadaća koje obavljaju. Danas poznajemo više od 200 različitih tipova stanica. U specijaliziranim stanicama samo su određeni geni aktivni, dok je većina ostalih gena u potpunosti blokirana. Taj proces specijalizacije stanica naziva se diferencijacija. Kada jednom imamo diferencirane stanice (stanice mozga, krvne stanice, jetrene stanice, mišićne stanice...), one se rijetko ili nikada ne dijele (umnožavaju) i ne mogu se u živom organizmu više vratiti u prvotni, nespecijalizirani oblik. Nove diferencirane stanice mogu nastati jedino iz nespecijaliziranih stanica koje zovemo matične stanice. Embrionalne matične stanice Takve matične stanice mogu se gotovo neograničeno umnožavati te se u određenim uvjetima mogu specijalizirati u bilo koji tip stanica u našem tijelu, zbog čega kažemo da su one pluripotentne. Embrionalne matične stanice dobivaju se iz embrija ili zametaka (stadij blastociste) 4 - 5 dana nakon oplodnje. Dio blastociste (embrioblast) se presadi u Petrijevu posudicu te se u laboratorijskim uvjetima te stanice umnožavaju i održavaju u nespecijaliziranom obliku. Znanstvenici još uvijek ne znaju sve potrebne mehanizme koji će usmjeriti razvoj embrionalnih stanica u svih 200 tipova stanica u tijelu. Ipak, do sad je eksperimentalno dokazano da stanice gušterače nastale iz embrionalnih matičnih stanica, i transplantirane u miševe koji imaju dijabetes, proizvode inzulin i dovode do izlječenja bolesnih miševa. Kod modela srčanog infarkta, srčane mišićne stanice nastale iz embrionalnih matičnih stanica zamjenjuju oštećene mišićne stanice te uvelike pomažu u oporavku srca. Jednako tako, znanstvenici su uspjeli proizvesti i nadomjestiti neurone koji proizvode dopamin u životinjskom modelu Parkinsonove bolesti te na taj način smanjili simptome te bolesti. Iako embrionalne matične stanice najviše obećavaju, njihova je uporaba popraćena moralnim pitanjima i dilemama. Zasad se, kao izvor tih stanica koriste embriji nastali za potrebe umjetne oplodnje iako se mogu koristiti i embriji nastali transplantacijom jezgre bilo koje stanice tijela donora u neoplođenu jajnu stanicu. Taj se postupak naziva terapijsko kloniranje. Prednost ovako nastalih embrionalnih matičnih stanica je u tome što nakon transplantacije u donora ne izazivaju obrambenu (imunološku) reakciju organizma. Ti embriji nikad neće biti presađeni u maternicu u svrhu reprodukcijskog kloniranja tj. stvaranja novog genetski identičnog ljudskog bića, što je i u većini zemalja zakonski zabranjeno. Kako se prilikom prikupljanja embrionalnih matičnih stanica zametak mora žrtvovati, znanstvenici se okreću drugim tipovima matičnih stanica kao što su matične stanice odraslih ili, pak, matične stanice dobivene iz krvi pupkovine, a puno se truda i sredstava ulaže u istraživanje načina kako bi se iz diferenciranih stanica (primjerice kože) stvorile matične stanice bez uporabe jajnih stanica. Matične stanice odraslih Matične stanice odraslih, koje u tijelu čovjeka služe kao izvor specijaliziranih stanica, možemo naći u mozgu, perifernoj krvi, koštanoj srži, mišićima, koži i jetri. Primjerice, matične stanice iz odraslog mozga već su djelomično specijalizirane, tako da se mogu dalje usmjeriti jedino prema nastanku moždanih stanica (neurona te drugih stanica mozga kao što su astrociti). Takve matične stanice nazivamo multipotentnima jer iz njih može nastati samo mali broj tipova specijaliziranih stanica. Iz matičnih stanica kože može nastati samo jedan tip stanica, te se te matične stanice nazivaju unipotentnima. Problemi kod istraživanja i uporabe matičnih stanica odraslih javljaju se zato što iz njih ne mogu nastati svi tipovi stanica. Ipak odnedavno postoje naznake da se hematopoetske (krvotvorne) matične stanice iz koštane srži mogu diferencirati i u neurone, mišićne stanice, srčane stanice i stanice jetre, a moždane matične stanice u stanice krvi i mišićne stanice. Takva nedavno opisana pojava pretvorbe matičnih stanica naziva se transdiferencijacija. Matične stanice iz krvi pupkovine Velika prednost matičnih stanica dobivenih iz krvi pupkovine jednostavno je prikupljanje prilikom poroda bez opasnosti za majku i dijete te jednostavno skladištenje u tekućem dušiku na -196 ºC kroz dugi niz godina. Te stanice je odnednavno moguće uskladištiti i kod nas na Zavodu za kliničku transfuziologiju Kliničkog Zavoda za laboratorijsku dijagnostiku KBC-a Zagreb. Cijena prikupljanja uzoraka je tisuću kuna, a samog skladištenja do 18 rođendana osobe kojoj pripadaju 15 tisuća kuna. Prednost tih stanica je, kao i kod stanica dobivenih terapijskim kloniranjem, u tome što kod vraćanja tih stanica u osobu od koje su potekli ne dolazi do stvaranja obrambene reakcije. Iako su te matične stanice slične hematopoetskim matičnim stanicama, pokazano je da transdiferencijacijom iz njih mogu nastati i drugi tipovi stanica koji ne pripadaju krvi. Iako je još dosta istraživačkog rada pred nama, buduća upotreba matičnih stanica u terapiji sve većeg broja bolesti današnjice je neupitna. Hoćemo li koristiti matične stanice porijeklom iz embrija koji su ostali nakon umjetnih oplodnji, ili odrasle matične stanice, ili pak one iz pupkovine, nije samo pitanje istraživača i novih znanstvenih spoznaja, već i etičko, političko i zakonodavno pitanje, a uz to i pitanje koliko smo daleko spremni ići kako bismo iskorijenili najveće i najteže bolesti današnjice. POVIJEST MATIČNIH STANICA1981. Martin Evans sa Sveučilišta Cambridge u Velikoj Britaniji uveo je pojam embrionalne matične stanice. James Thomson sa Sveučilišta u Winsconsinu razvio je tehniku za izolaciju i održavanje ljudskih embrionalnih stanica u kulturi. Znanstvenici su uspjeli klonirati rani (4 - 6 stanica) ljudski embrio u svrhu stvaranja embrionalnih matičnih stanica. Znanstvenici sa Sveučilišta Kingston u Velikoj Britaniji otkrili su treću vrstu matičnih stanica iz krvi pupkovine. Znanstvenici u Velikoj Britaniji stvorili su umjetne stanice jetre iz matičnih stanica dobivenih iz krvi pupkovine. Mario Capecchi, Martin Evans i Oliver Smithies dobili su Nobelovu nagradu za fiziologiju i medicinu za rad na embrionalnim matičnim stanicama iz transgeničnih miševa. Steinberg GK i suradnici sa Svučilišta Stanford u SAD-u su pokazali da neuroni dobiveni iz ljudskih embrionalnih matičnih stanica dovode do oporavka štakora koji su preživjeli moždani udar.