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Stem cells

Dimulai oleh advisor, November 15, 2006, 09:39:50 AM

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0 Anggota dan 9 Pengunjung sedang melihat topik ini.

peregrin

permisii... OOT nih ;D ... cm numpang lewat  ;D
Free software [knowledge] is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'. (fsf)

reborn

Thanks. Dibiarin aja di situ, mana tau ada yang mau baca2 juga. 15 files total nih dari peregrin asik ;D

reborn

Wew.... lagi banyak artikel stem cells hari ini  :o

Study: Spinal cord can repair itself

U.S. scientists say they have disproved the long-held theory that the spinal cord is incapable of repairing itself. The Johns Hopkins University researchers say human nerve stem cells they transplanted into damaged spinal cords of rats have survived, grown and in some cases connected with the rats' own spinal cord cells.

Human nerve stem cells transplanted into rats’ damaged spinal cords have survived, grown and in some cases connected with the rats’ own spinal cord cells in a Johns Hopkins laboratory, overturning the long-held notion that spinal cords won’t allow nerve repair.

A report on the experiments will be published online this week at PLoS Medicine and “establishes a new doctrine for regenerative neuroscience,” says Vassilis Koliatsos, M.D., associate professor of neuropathology at Johns Hopkins. “The spinal cord, a part of the nervous system that is thought of as incapable of repairing itself, can support the development of transplanted cells,” he added.

“We don’t yet know whether the connections we’ve seen can transmit nerve signals to the degree that a rat could be made to walk again,” says Koliatsos, “We’re still in the proof of concept stage, but we’re making progress and we’re encouraged.”

In their experiments, the scientists gave anesthetized rats a range of spinal cord injuries to lesion or kill motor neurons or performed sham surgeries. They varied experimental conditions to see if the presence or absence of spinal cord lesions had an effect on the survival and maturation of human stem cell grafts. Two weeks after lesion or sham surgery, they injected human neural stem cells into the left side of each rat’s spinal cord.

After six months, the team found more than three times the number of human cells than they injected in the damaged cords, meaning the transplanted cells not only survived but divided at least twice to form more cells. Moreover, says Koliatsos, the cells not only grew in the area around the original injection, but also migrated over a much larger spinal cord territory.

Three months after injection, the researchers found evidence that some of the transplanted cells developed into support cells rather than nerve cells, while the majority became mature nerve cells. High-powered microscopic examination showed that these nerve cells appear to have made contacts with the rat’s own spinal cord cells.

Source: Johns Hopkins University

reborn

Hmm... ini pendekatan quantitative biology, rada2 membosankan mungkin yahh  :-\


Towards an understanding of lineage specification in hematopoietic stem cells: A mathematical model for the interaction of transcription factors GATA-1 and PU.1


Authors: Ingo Roeder, Ingmar Glauche


In addition to their self-renewal capabilities, hematopoietic stem cells guarantee the continuous supply of fully differentiated, functional cells of various types in the peripheral blood. The process which controls differentiation into the different lineages of the hematopoietic system (erythroid, myeloid, lymphoid) is referred to as lineage specification. It requires a potentially multi-step decision sequence which determines the fate of the cells and their successors. It is generally accepted that lineage specification is regulated by a complex system of interacting transcription factors. However, the underlying principles controlling this regulation are currently unknown.

Here, we propose a simple quantitative model describing the interaction of two transcription factors. This model is motivated by experimental observations on the transcription factors GATA-1 and PU.1, both known to act as key regulators and potential antagonists in the erythroid vs. myeloid differentiation processes of hematopoietic progenitor cells. We demonstrate the ability of the model to account for the observed switching behavior of a transition from a state of low expression of both factors (undifferentiated state) to the dominance of one factor (differentiated state). Depending on the parameter choice, the model predicts two different possibilities to explain the experimentally suggested, stem cell characterizing priming state of low level co-expression. Whereas increasing transcription rates are sufficient to induce differentiation in one scenario, an additional system perturbation (by stochastic fluctuations or directed impulses) of transcription factor levels is required in the other case.

PDF : [pranala luar disembunyikan, sila masuk atau daftar.]



Ini lebih parah, pake simulasi Monte Carlo  :P Buat yg di biofisika kali yahh ini  ??? Tapi dikit banget kok ini.

Simulation of stem cell survival in small crypts

Authors: Dietrich Stauffer, Eytan Domany

Monte Carlo simulations of the number of stem cells in human colon crypts allow for fluctuations which kill the population after sufficiently long times.

PDF : [pranala luar disembunyikan, sila masuk atau daftar.]

reborn

Bye bye silicon  ;D  :-X

news.bbc.co.uk/1/hi/health/6354451.stm

KutipStem cells used to boost breasts

Scientists in Japan claim to be able to increase the size of a woman's breasts using fat and stem cells.

The technique uses fat from the stomach or thigh which is then enriched with stem cells before being injected.

It is hoped the method could prove a more natural-looking alternative to artificial implants filled with salt water or silicone.

Oke, ini ada satu lagi. Beneran geregetan gw sama stem cells nih

newswire.rockefeller.edu/?page=engine&id=592   

KutipScientists clone mice from adult skin stem cells

The potential of stem cells has so far gone largely untapped, despite the great promise that stem cells hold. But new research from Rockefeller University now shows that adult stem cells taken from skin can be used to clone mice using a procedure called nuclear transfer.

Embryonic stem cells have received the most press for their potential to generate healthy cells and tissues that could replace damaged or diseased organs. “Scientists are well aware that tissue derived from someone else’s embryonic stem

Meet the clone. Rockefeller University researchers successfully created cloned mice from adult skin stem cells; 19 mouse pups were born and nine grew into normal, healthy adult mice.
cells would be recognized as foreign and rejected by the patient,” says senior co-author Elaine Fuchs, the Rebecca C. Lancefield Professor at Rockefeller and a Howard Hughes Medical Institute investigator. “This is one of the reasons why scientists have focused so much attention toward using nuclear transfer, which would allow us to use adult stem cells from the same patient rather than those harvested from an unrelated embryo.” Fuchs and her colleagues tested the method in adult stem cells taken from the skin of mice.

Using purification methods developed in Fuchs’s Laboratory of Mammalian Cell Biology and Development, postdocs Valentina Greco and Géraldine Guasch isolated stem cells from the mice’s hair follicles. They gave these stem cells to Jinsong Li, a postdoc in Rockefeller’s Laboratory of Developmental Biology and Neurogenetics headed by senior co-author Peter Mombaerts. To execute the nuclear transfer procedure, Li took unfertilized mouse oocytes and replaced the nucleus of each oocyte with a nucleus from the adult skin stem cells.

A main hurdle in nuclear transfer with adult cells has been its efficiency â€" out of a hundred attempts, only a handful may succeed â€" with reported success rates never reaching into double digits. “The efficiency of nuclear transfer is very low,” says Li. “Using purified adult skin stem cells as our source of nuclei, we have found that higher nuclear transfer efficiencies can be achieved.”

Greco, Guasch and Li compared the cloning efficiency of adult skin stem cells with that of more differentiated skin cells and also with cumulus cells â€" the cells that surround a developing oocyte and have traditionally been the preferred cell type for nuclear transfer. The stem cells gave the best efficiency, yielding 19 pups, nine of which grew up into normal, healthy, breeding adult mice. The findings are reported online today in the Proceedings of the National Academy of Sciences.

This is not the first time scientists have tried to use adult stem cells to clone mice. Experiments using adult hematopoietic stem cells â€" the cells in the bone marrow from which all blood cells are derived â€" were reported last year. But their conclusions were confusing, says Mombaerts, and there are no reports on using adult stem cells for reproducible cloning of mice that survive until adulthood. By using cells from the same mouse and performing the experiments on the two successive days, the Rockefeller scientists could directly compare adult stem cells with other cell types.

Nuclear transfer can also be used to make embryonic stem cell lines, a process which can be done in a tissue culture dish and which is simpler and more efficient than generating a cloned mouse. Although this procedure has not yet successfully generated human embryonic stem cell lines, once technological hurdles are overcome, it may be possible in the future to use a patient’s skin stem cells to tailor-make embryonic stem cell lines, circumventing the problem of immune rejection.

Such stem cells might also be used to study a variety of different diseases, for which patient tissue is often hard to come by. “There are many diseases, such as liver, pancreatic and neurodegenerative disorders where researchers are only able to obtain affected tissue from autopsies,” says Fuchs. If, on the other hand, scientists are able to generate embryonic stem cells from the skin of a patient, for example an Alzheimer’s patient, these embryonic stem cells might be used in the laboratory to enable scientists to generate neurons and study the neurodegenerative process.

peregrin

masih belum sempat baca2 nih  :( ... cuma ada bbrp hal yg nggak ngerti:

= kabarnya pernah ada kasus ada anak yg diterapi stem cell ini malah kemudian kena leukemia, krn stem cell-nya nggak bisa berhenti self-renewal. Emang dengar2 stem cell yg "nggak bisa dikontrol" gini malah bisa jadi tumor. Aq cari2 artikelnya ttg ini belum ketemu, yg bejibun mah artikel2 positif ttg prospek stem cell ini.

= sebenarnya prosesnya gimana to: setelah stem cell ini berdiferensiasi ke specialized cell type, apa kemudian dia cuma bakal regenerasi cell2 yg mati aja (spt sel normal) atau gimana? bisa dikontrol gak ini? kebayang yg utk implant breast, pengganti silikon, gimana ngontrol size-nya y (so berarti harus ngontrol pertumbuhan stem cell ini to)? atau paling nggak biar kiri kanan sama gitu hehe  ;D

= teman pernah cerita jg, utk stem cell yg berdiferensiasi ke neuron, ternyata hanya morfologinya aja yg bagus spt neuron asli, tp tdk bisa berfungsi (transimisi synaptic-nya nggak jalan)  :( ... barangkali ini khusus utk neuron aja sih yg emang spesial yah (apa sih yg gak spesial di fisiologi otak  ;)) ... kali di cell lain, stem cell lbh berhasil kali

???
Free software [knowledge] is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'. (fsf)

reborn

Kutipmasih belum sempat baca2 nih  :( ... cuma ada bbrp hal yg nggak ngerti:

blm sempet baca2 tapi dah bnyk pertanyaan, kok bisa  ::)

Saya juga gak gitu ngerti kok  :( cuma menarik aja keliatannya. Paling ikutin beritanya di [pranala luar disembunyikan, sila masuk atau daftar.]. Kayaknya emang masih terlalu baru buat terapi, emang dah ada yg pake ini buat terapi ???

Stem cells juga kan bnyk macemnya. Yang bnyk diteliti adult stem cells, soalnya yg embryonic stem cells nyangkut2 ke etika. Trus stem cells emang mungkin penyebab cancer, tapi kalo kita bisa tau persis sifat2nya kan bisa kita kontrol pada akhirnya.

Kutipatau paling nggak biar kiri kanan sama gitu hehe  ;D

OOT dikit, lah emang normalnya gak sama kan kiri dan kanan  ;D

peregrin

Kutipblm sempet baca2 tapi dah bnyk pertanyaan, kok bisa 

kalo cuma nanya aja ya cukup pake imajinasi pakde  ;D ... khan jaka sembung asal nyambung  ;D hehehe ... untungnya di FS, nanya segala macam hal boleh khan  ;)


KutipStem cells juga kan bnyk macemnya. Yang bnyk diteliti adult stem cells, soalnya yg embryonic stem cells nyangkut2 ke etika.

o gitu ya .. hmm.. ok d, ntar lihat2 lagi d :)
Free software [knowledge] is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'. (fsf)

reborn

eh eh, ini kok aneh.

[pranala luar disembunyikan, sila masuk atau daftar.]

Kutip
A team of Korean scientists has come close to creating interspecies stem cells by combining monkey cells with cow ova for the first time in history.

When applied to human cells, the feats are expected to accelerate cell therapy aimed at healing incurable diseases such as diabetes or Alzheimer's.

itu sapi tujuannya apaan yahh  ???
Kutip
Scientists have made monkey blastocysts through intra-species nuclear transfer _ implanting monkey somatic cells into enucleated monkey ova. But this is the first time that a blastocyst has been established while using non-monkey ova.

Kalo intra-species dah bisa, ngapain harus Iiter-species stem cells? Ah, susahnya jadi oon  :(

peregrin

#24
wah ada edisi khusus stem cell dr Nature Juni 2006 kemarin. Aq attach2 di sini ya, moga2 gak kedobelan  ;D

sumber: Nature Vol 441, 29 June 2006

ada webforum-nya juga buat yg bisa akses:
[pranala luar disembunyikan, sila masuk atau daftar.]

Free software [knowledge] is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'. (fsf)

peregrin

lagi sekalian ;D

masih sumber yg sama: Nature Vol 441, 29 June 2006
Free software [knowledge] is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'. (fsf)

peregrin

hm... jd penasaran sampe di mana stem cells ini sudah / sedang akan digunakan dlm terapi.

Ini ttg clinical trial, berita lama sih, th 2005 ... skr gimana ya perkembangannya  ???

[pranala luar disembunyikan, sila masuk atau daftar.]

Race to Human Stem-Cell Trials

By Kristen Philipkoski
02:00 AM Apr, 19, 2005

SAN DIEGO -- Several scientists have used embryonic or fetal stem cells to help rodents with spinal cord injuries walk again. The researchers travel the country showing videos of rats dragging their hind legs, followed by clips of them miraculously hopping around following stem-cell injections.

The question now, especially in the minds of the 250,000 people in the United States with spinal cord injuries, is: When will the research transfer into helping humans? The answer depends on who you ask. Some scientists believe it could happen as soon as the end of this year. Others say that's too soon, and data from larger animals such as dogs or monkeys is necessary before researching with humans.

Evan Snyder of the Burnham Institute in La Jolla, California, is one of those video-toting researchers. Last week at a small stem-cell conference here, he showed the dramatic improvement (.mov) in rats he achieved in 2002.

Despite those positive results with rats, Snyder believes more work must be done before doctors try the experiment on humans. The controversy surrounding embryonic and fetal stem-cell research means the first human clinical trial using the cells will be under a microscope in more ways than one, he said. If something goes awry, opponents of killing embryos for research will be poised to quash future research.

"The last thing we need is another Jesse Gelsinger," Snyder said, referring to the 18-year-old man who died during a gene-therapy trial at the University of Pennsylvania in 1999. After Gelsinger's death, the Food and Drug Administration closed many gene-therapy trials around the country.

Stem cells have the unique potential to self-renew, and to become various cell types. Researchers believe those taken from embryos to be the most flexible kind. Adult stem cells, derived from bone marrow, blood, skin, hair follicles, nasal passages and the brain, come without the ethical quandary, but some scientists doubt they have as much potential as embryonic stem cells.

In 2001, President Bush declared that no federal funds could be spent on embryonic stem-cell lines developed after that date. Since then, many states have taken on funding efforts, but most of the work mentioned in this story was funded privately.

Researcher Hans Keirstead, who also has helped rats with spinal cord injuries to walk again, isn't convinced that primate studies are necessary before testing in humans. Some scientists believe human stem cells are more similar to rodents than monkeys, he said. Keirstead, an assistant professor of anatomy and neurobiology at the Reeve-Irvine Research Center, said he will publish his research soon in a scientific journal.

"Are we going to learn anything from the monkey studies?" he said. "If so, then yes, we should do them. If not, then it's a waste of time and a delay for getting into humans."

Keirstead has been criticized by fellow researchers for hyping his research and moving too fast. But he said patient safety and being honest with patients about potential outcomes are his top concerns.

Geron, a publicly traded stem-cell company, is performing studies that could lead to an Investigational New Drug application with the FDA based on Keirstead's research, which the company funded1. An IND application is the first step to beginning a clinical trial.

Thomas Okarma, Geron's CEO, is even less convinced that larger animals are necessary before testing Keirstead's technique in humans. During an interview at the conference, he said he believes the clinical trial could begin in mid-20062.

Some scientists believe that time frame is too aggressive for the study, which most likely would center on recently injured patients (about a week post-injury), since researchers haven't yet seen success in animals with chronic injuries.

"I think that Geron is offering an optimistic time frame, which is what public companies sometimes do when they haven't ever done a clinical trial before," said Jeanne Loring, adjunct associate professor in stem cells and regeneration at the Burnham Institute.

Geron's Okarma, however, cites two of Keirstead's Geron-funded studies as a foundation for human trials. One treated the "shiverer" mouse, which lacks the protective coating around its nerves called myelin, causing it to shake. Keirstead's stem-cell therapy calmed the shivers.

The second is Keirstead's success in treating rats with spinal cord injury, or SCI, videos of which he revealed to the public in 2002. The work will appear "within weeks," Okarma said, in the journal Neuroscience3.

"We've shown it works in two different models: the shiverer mouse and the SCI rat," Okarma said. "So what if you showed it in the monkey or a cat where frankly the science is not validated? Plus, no one wants to make monkeys spinal-cord injured."

Keirstead said he is performing further research to determine whether larger animal studies should be done, "but it's incorrect to say monkey work is necessary for every single therapy."

Meanwhile, the FDA's main concern is the potential toxicity of the therapy, according to Okarma.

Geron's pre-IND studies include six- to 12-month toxicity studies in mice and rats, he said. When they are complete, he hopes the FDA will grant approval to move the research into human subjects. He emphasized he has no interest in rushing into a study that might be unsafe, but unnecessarily delaying a therapy would be just as tragic.

"The world spotlight is going to be on this and the last thing we want to do is make patients worse," Okarma said. "So we're turning every stone over to rule out ways in which these cells could be harmful -- as well as to optimize a production scheme to find the cell types that are ultimately likely to be beneficial."

Some researchers, like Snyder, don't believe spinal cord injury should be the subject of the first human embryonic stem-cell trial. His lab is working on other projects, including ways to engineer stem cells to home in on brain tumors, as well as treatments for amyotrophic lateral sclerosis (or Lou Gehrig's disease), conditions he believes would be more appropriate targets for the first human applications.

Snyder said he and Keirstead are friends, and they have discussed combining their approaches to spinal cord injury. Still, Snyder takes a more conservative approach. He believes trying to rewire the entire spinal cord is too complicated at this point in the research, and a clinical trial would need to have very modest end points or risk being a big disappointment.

"For example, if someone had C6 injury, and I was able to buy him function down to C7," Snyder said, the patient would benefit. "If you had even bought Christopher Reeve an extra segment of spinal function he would be off his ventilator. He would not be running a marathon, but you've changed his life."

Scientists at Advanced Cell Technology, another publicly traded company, are also moving toward clinical trials with retinal cells derived from embryonic stem cells. Dr. Robert Lanza, Advanced Cell's vice president of medical and scientific development, said he hopes to be engaged in human clinical trials "in a couple of years."

Other ailments are also in the running to become the subject of the first embryonic stem-cell clinical trial, said Advanced Cell's president and chief scientific officer, Michael West. Blood diseases such as AIDS, anemia and cancer -- as well as skin and hair transplants -- could be low-hanging fruit for stem-cell therapies, West said. However, West would not confirm whether Advanced Cell has programs in those areas.

Doctors in other countries, including Portugal, China, Australia and Russia, have forged ahead with some success using both adult and embryonic stem cells in spinal cord injury patients.

But in the United States, it's not up to the scientists to decide when they can begin human clinical trials. The FDA must approve three levels of clinical trials in order for any therapy to move forward. The agency then decides if doctors can prescribe the treatment based on whether the data shows the potential benefits outweigh the risks.
Free software [knowledge] is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'. (fsf)

peregrin

nemu yg lebih baru  :D

[pranala luar disembunyikan, sila masuk atau daftar.]

Scrutinizing a Stem Cell Trial

By Steven Edwards| Also by this reporter
02:00 AM Mar, 29, 2006

As a quadriplegic, I've read a lot of hype about paralysis cures. So I was eager to find out if Geron, a California stem cell company, had the substance to back up its claims of being poised to launch the world's first clinical trial of an embryonic stem cell-based therapy to treat spinal cord injury.

Going into my interview with Tom Okarma, the company's CEO, I knew this trial would not benefit me directly because it will focus on recent injuries -- I was injured nine years ago in a car accident that rendered my body paralyzed from the shoulders down.

My concern was that Geron's scientists were being hasty. If the first embryonic stem cell trial failed miserably because the company's researchers weren't cautious enough, funding for other research projects would likely diminish and ultimately keep me paralyzed longer.

After an hour of speaking to Okarma, fears of a half-baked trial dissipated. He readily answered my many questions. If he didn't have the animal data to answer a query, he didn't try to dance around that fact.

Okarma outlined a structured but malleable trial. I initially had reservations about safety, but Okarma emphasized that if the animal data is not good, the study will not move forward until problems are addressed.

I'm reassured the trial will proceed with as safe a framework as is possible. Whether it will work remains to be seen. That's why we have clinical trials.

Wired News: In April of 2005, Geron was conducting preliminary toxicity studies (known as pre-investigational new drug, or pre-IND, studies) in animals to address Food and Drug Administration concerns. How are they going?

Tom Okarma: We will complete our IND-enabling studies, which are now in process and still on track, and file our IND during the fourth quarter of this year, assuming the preclinical data continue to go well. That starts a 30-day review clock by the FDA, who then has 30 days to either accept our IND and allow us to proceed or, at that point, they have questions that we must answer before we can begin. We are on track for that. So, assuming they bless the IND, we would hope to be in the clinic in the first quarter of (2007).

The toxicity studies that we do are fairly standard for any new product going into man, with the addition that we do chronic toxicity because this is not a drug that would be excreted in 24 hours. There are cells that will stay in, hopefully indefinitely, so both the toxicity and the tumorigenesis (tumor growth) studies are six and 12 months in duration.

WN: Will patients have to worry about immune rejection with the cells you're injecting (called oligodendrocyte progenitor cells, or OPCs)?

Okarma: It turns out that the differentiated cells that we make and put into animals are not recognized by the human immune system, and we published this last year. It's a striking finding.

WN: In the animal studies that you're doing, how do you deliver the OPCs?

Okarma: Directly into the injury site. In the clinical human trials, they will be injected directly into the injured spinal cord site either during spine stabilization surgery or, depending on when that's performed, percutaneously (through the skin) in a separate procedure. We've developed a gizmo that has a fiber-optic device to enable the neurosurgeon to visually watch the needle as the instrument places it appropriately into the spinal cord and injects the cells so they migrate once they're injected into the cord in between the injured axons and find their way to create the myelin sheath (the protective coating of nerve fiber).

WN: Last year, scientists reported that some of the embryonic stem cells approved for federal funding and available at the National Institutes of Health are contaminated by animal cells. Will the cells you transplant be grown in all-human media, free of animal products?

Okarma: Better than that. Not only all-human, it's all defined chemically. So there's no serum in it. There's no conditioned medium that has undefined materials in it. So it's very squeaky clean, as is the differentiation process now done under good manufacturing practices (GMP) here.

We've got the world's only GMP master cell bank of human embryonic stem cells with lines that are fully qualified for human use which, by the way, are two of Bush's approved lines. So the stuff you hear published that all of those lines are irrevocably contaminated with mouse materials and could never be used in people -- hogwash. If you know how to grow them, they're fine.

WN: The primary focus for Phase 1 trials are safety. What outcomes are you looking for in these first trials to convince you to move into Phase 2 trials?

Okarma: We're (planning on) doing a Phase 1-2, it's a combination. We will test this in patients with the injury. A pure Phase 1 is done in people without a disease; we're doing this in diseased patients, so it's a Phase 1-2. It will be a controlled trial -- not randomized, not blinded, but controlled. We do expect that there will be some patients who will not want the cells, and we would hope that they would be willing to be in the control group, meaning they're matched by the extent of the injury and other patient characteristics to the patients who get the cells so that we can actually compare the rehab progress of these patients with and without the cells.

We recognize that the world's spotlights are going to be on this. So we want to structure out as much subjective stuff as we possibly can. That's the first point. The second point, again to your point of safety, is that the initial patients in the trial a) will get a very low dose of cells, which is always done with a new therapy. They just start with less than the therapeutic range because you want to be sure there's no toxicity associated with this.

How are we going to monitor for toxicity in a patient that has a complete thoracic injury, that has no sensation below the point of injury? Well, if we start with a T3 lesion (an injury at the third vertebra in the thoracic region of the spinal cord), the question will be: Do we see evidence of an ascending paralysis? In other words, changing patients' physiology from a T3 lesion to a T2 or a T1, ascending toxicity.

We start with complete patients because they have no hope of recovery and we want to offer them something. We're starting with thoracic lesions because there's no significant impact for the patient should we see toxicity go from, say, a T3 to a T2 lesion. If we had started with cervical complete lesions and went from C4 to C2, that would be significant because we would reduce respiratory drive.

We're turning every single stone over that we can to reduce -- if not eliminate -- the risk to these patients who volunteer to get the cells for the first time. Once we go through the initial safety cohorts ... then we start looking at incomplete lesions. For all these patients, the efficacy is based on three simple principles: Do we restore sensation in any way or conversely reduce neuritic plan? Do we change bowel or bladder control? Do we see patients enjoying some degree of local motor recovery?

All of these things are monitored by America Spinal Injury Association, which have been developed to follow patients with incomplete lesions who can respond modestly to intense physical therapy. All of those endpoint measures are all validated and ready for us to use. We didn't have to invent anything.

Our fondest hope is that, even in cases that have no hope of spontaneous recovery, we actually provide value. Now that may not happen. We may not see any responses in the first cohorts of patients who have complete lesions, which is why we're progressing thereafter to patients with incomplete lesions which resemble more closely the animal model, which is where the excitement began. Those animals are models of incomplete lesions. But for reasons of ethics and safety and appropriateness, we can't start with patients who resembled the animal model. You have to start way upstream.

WN: Will those who choose to be in the control group receive methylprednisolone, the currently recommended treatment for acute spinal cord injury?

Okarma: Everybody in both groups will get that.

WN: That sounds good. Thank you for your time, and I hope you have a good day.

Okarma: You, too. Bye-bye.

Free software [knowledge] is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'. (fsf)

peregrin

penjelasan bagus ttg stem cell transplant (bone marrow transplant):
[pranala luar disembunyikan, sila masuk atau daftar.]

animation:
[pranala luar disembunyikan, sila masuk atau daftar.]

dan ini jurnal khusus stem cells, udah tahu belum dan bisa dibuka gak ya  ???
[pranala luar disembunyikan, sila masuk atau daftar.]

artikel2 stem cells gratis di NYTimes:
[pranala luar disembunyikan, sila masuk atau daftar.]


hm... udah deh  ;D  gw sendiri belum baca  ;D

Free software [knowledge] is a matter of liberty, not price. To understand the concept, you should think of 'free' as in 'free speech', not as in 'free beer'. (fsf)

reborn

ampun... banyak amat peregrin.. thanks banget lho ya... numpang sedot ;D