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More on Stem Cells

Posted Jun 08 2010 7:35pm
If you've been following awhile, you know my stance on stem cells... and if you haven't, don't waste your time feeding me your negativity in regards to a topic I know nearly inside and out and have a great amount of faith in. I have heard it all, and it is safe to say that you can never say anything to me to make me give up on my belief that the power of stem cells is immense. Hope never dies for me, but sometimes it gets a bit dim...hard to not when each day you are faced with a battle against a "terminal" condition for your child. However, every new day brings something new that successfully reignites that hope...that's the blessing of a new day, right? Today, this is it, from The Medical News Web site: 

UCSF scientists discover new stem cell in developing human brain
26 May 2010 05:42

UCSF scientists have discovered a newstem cell in the developing human brain. The cell produces nerve cells that help form the neocortex - the site of higher cognitive function -- and likely accounts for the dramatic expansion of the region in the lineages that lead to man, the researchers say.

Future studies of these cells are expected to shed light on developmental diseases such as autism andschizophrenia and malformations of braindevelopment, including microcephaly, lissencephaly and neuronal migration disorders, they say, as well as age-related illnesses, such as Alzheimer's disease.

Studies also will allow scientists to track the molecular steps that the cell goes through as it evolves into the nerve cell, or neuron, it produces. This information could then be used to prompt embryonic stem cells to differentiate in the culture dish into neurons for potential use in cell-replacement therapy.

"This discovery has the potential to transform our understanding of the development and evolution of the human neocortex, the most uniquely human part of the centralnervous system," says the senior author of the study, neurologist Arnold Kriegstein, MD, PhD, director of the Eli and Edythe Broad Center of Regeneration Medicine andStem Cell Research at UCSF.

"It also should inform our understanding of developmental diseases and advance the creation of cell-based therapies. Many neurological diseases develop in neurons or the neural circuits between them. If we're going to understand how these disorders develop, we have to better understand how the human and primate cerebral cortex develops."

In rodents and humans, the developing cortex contains a layer of neural stem cells called radial glial cells that resides near the fluid-filled ventricles and produces cells that are precursors to neurons. These precursor neurons further proliferate in a region known as the subventricular zone (SVZ), to increase their numbers, and then differentiate into newborn neurons. The neurons then migrate along radial glial fibers up to the neocortex, where they help form the tissue that is the site of sensory perception, motor commands, spatial reasoning, conscious thought and language.

In human and nonhuman primates, however, the SVZ has a massively expanded outer region, known as the outer subventricular zone (OSVZ). About 20 years ago, scientists presumed that the OSVZ also contained stem cells, but until now they have lacked evidence.

In the current study, lead authors David V. Hansen, PhD, a postdoctoral fellow, and Jan H. Lui, a graduate student in the Kriegstein lab, examined the OSVZ, using new labeling and tracking techniques to follow individual cells and their progeny over time in cultured tissue slices from fetal cortex tissue that had been donated for research.

They characterized two kinds of cells within the region -- both the novel neural stem cell and its daughter cell, known as the transit amplifying cell. The stem cell closely resembles the radial glial cell in structure and behavior and, like the radial glia, has radial fibers which newborn neurons migrate along up to the neocortex.

The region is a busy hub of cell proliferation. The stem cell undergoes asymmetrical cell division, giving rise to two distinct daughter cells -- one a copy of the originalstem cell, the other a transit amplifying cell. The transit amplifying cell undergoes multiple rounds of symmetrical divisions before all of its daughter cells begin the process of differentiating into neurons.

"We are very interested in understanding how these modes of division are regulated," says Kriegstein. "We suspect that faults in cell-cycle regulation account for a variety of developmental brain diseases."

More broadly, he says the team wants to understand how the new stem cells compare to radial glial cells and how the two sets of neurons they produce integrate in the neocortex. "Neurons are probably being generated in both the SVZ and OSVZ at once," he says. "They likely end up in the same layer of the neocortex as they migrate into position and start forming circuits.

"This suggests to us that there may be a mosaic of cell types in the human neocortex, in which there are cells that originate in the traditional zone and cells produced in the newer zone that intermix in the cortex. The complexity of primate neocortex may be significantly increased by the interaction of the evolutionarily-speaking 'younger' neurons with those originating in the more primitive zone."

The massive number of cells within the OSVZ of humans "tells us we have to be careful when modeling human brain diseases in mice," says Kriegstein. "Especially in the neocortex -- the most highly developed part of the brain in primates and humans - there are going to be important differences between rodents and humans."

Now to get the United States on board with stem cell treatments so families are not investing their entire lives in to saving their children by venturing to far off places like China and Russia, or risking their lives by venturing to Mexico and other unsafe areas that are offering hope that the US won't. From the Washington Post :

Frontiers of stem cell treatment offer hope, risks to those in U.S.
By Ariana Eunjung Cha / The Washington Post
Published: June 08. 2010 4:00AM PST

BEIJING — Disillusioned by U.S. doctors who could not help their daughter with cerebral palsy, Kara Anderson’s parents did something they could not have imagined a few years ago: They took her to China.

Specialists in the Chicago area, where the family lives, said that Kara’s brain injury was permanent and that the 9-year-old would probably end up in a wheelchair because of severe twisting in her leg muscles. But then her parents began hearing stories about children who had improved after receiving injections of stem cells.

The treatment was not available in the United States. It was commercially available only abroad.

That’s how the Andersons joined the desperate people who are taking leaps of faith in seeking stem-cell treatments in places as far away as China, India, Russia and Brazil.

Western scientists worry that patients are being taken in by slick marketing campaigns, wasting time, money and hope on unproven therapies, and perhaps even putting themselves in danger.

“Unregulated therapy in the absence of any evidence that these cells are going to help patients is reckless. The potential to do harm is enormous,” said Arnold Kreigstein, a neurologist who is director of stem cell research at the University of California at San Francisco.

Scientists hope various kinds of stem cells can eventually be used to treat devastating and common ailments: heart attack, stroke, Parkinson’s disease, diabetes, liver failure, even blindness. For now, there is scant evidence for the benefits of treatments such as the ones the Andersons sought.

Most of the stem cells used in Chinese clinics are obtained from fetuses from miscarriages. They thus fall somewhere between embryonic stem cells, which come from early-stage embryos — raising ethical and religious questions about their use — and adult stem cells, which are easier to obtain and are considered safer and less controversial.

They are widely considered to be less versatile than embryonic stem cells, which can develop into almost every kind of cell in the body, but more so than adult stem cells, which are useful only to treat the tissues or organs from which they came.

Fetal stem cells also have a downside: They can trigger immune-rejection responses or lead inadvertently to new or increased pain. They also have a tendency to clump together; one patient who sought treatments in Russia developed multiple brain tumors after undergoing experimental therapy with fetal stem cells, scientists reported in the journal PLoS Medicine.

Research rivalry

Stem cell research is an area in which the United States faces new rivals — and ones willing to move quickly from experimental research to treatment. A January report by the National Science Board warned that the U.S. position as the world’s innovation leader is declining and China’s influence is increasing. The report said that is the result of a surge in government investment in science and technology education, infrastructure and research.

In the United States, the use of federal funding for new lines of embryonic stem cells was banned in George W. Bush’s administration. President Barack Obama reversed that decision when he took office, but China and other countries have had a years-long head start.

Treatments using embryonic or fetal stem cells are in the experimental stage in the United States and are not approved for commercial use by the Food and Drug Administration. But they remain in a regulatory gray area in China, neither sanctioned nor banned.

The government allows 50 or so stem cell clinics to operate freely. Several Chinese health officials have expressed concern about the lack of oversight. Scholars affiliated with the government say they expect some regulations to be introduced soon.

The one trial of fetal-derived stem cells that has been started in the United States has been limited to a few patients, and none using embryonic stem cells has begun. In China, thousands have undergone treatment with embryonic, fetal, adult and cells taken from a newborn’s umbilical-cord blood, Chinese scientists say. But evidence that treatment is working is merely anecdotal.

“People flock to the words ‘stem cells’ because they rightly feel that the potential is enormous. I’m right there with them, but there’s a misalignment of progress in the scientific and medical communities with the public perception of the power of stem cells,” said Hans Keirstead of the University of California at Irvine, who specializes in research on embryonic stem cells and spinal cord injury.

Stem-cell treatment in China is both a government-sponsored and a commercial enterprise, with wildly varying methodologies, facilities and prices.

Chinese doctors consider the Wu Stem Cells Medical Center, where Kara was treated, among the country’s premier facilities for central nervous system illnesses. Located across from an amusement park in southern Beijing and inside a traditional Chinese medicine hospital, it charges $30,000 for a five-week treatment.

Cheng Bo, deputy director of the center, said doctors there offer potential patients realistic assessments of the risks and benefits. “We tell them it’s impossible to cure patients completely,” he said. “Our goal is to improve the quality of their life or to extend their life.” Many patients — about a third are children — come from developed countries where medical treatment is in general considered superior to China’s, although they may lag behind China in stem cell research.

Kara’s improvement

Kara managed the improbable after the first two of four stem cell shots in January. She began limping around on a crutch and walking up to 15 minutes on a treadmill with the support of a rail, according to her parents and doctors. She could lift pebbles with her left hand and raise it over her head, which she could never do before.

Her father, Brian Anderson, who learned about the treatment from a relative who suggested he do research on the Internet, said recently Kara has retained these abilities since her treatment in December. He said he is also noticing improvement in her eyesight.

“We really weren’t sure what to expect, but she got better and better every day. It was unbelievable,” said Anderson, 41, a construction contractor, who funded the trip and treatment with money pooled from relatives, friends and their church.

Doctors said the timing of Kara’s improvement may have been coincidental: Cerebral palsy symptoms periodically get better or worse for unknown reasons, but stories such as hers disseminated on the Internet are attracting thousands of patients.

In the United States, a trial involving infusions of embryonic stem cells for patients with spinal cord injury was delayed from January until August to address safety concerns raised by the FDA. Keirstead, whose work is the basis for that trial and in 2005 made headlines for getting injured rodents to walk again, said he is eager to see the trial started.

“I was jumping for joy to see those first rats walk again, thrilled when I saw the technology progress to the clinic, overjoyed to see FDA approve it,” Keirstead said. “Now we are on the cusp of seeing this in humans, and I am dismayed and frustrated at how long it is taking because the need is so great.”

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