Archive for September, 2009
Mother Nature Gives Clues For Improving Stem Cell Techniques, TAU Scientists Discover
Last Updated on Wednesday, 30 September 2009 05:00 Written by Wednesday, 30 September 2009 05:00
Hikers know that moss on a tree trunk always points north. According to new research by Israeli and German scientists, this ancient plant may also provide a new “compass” for stem cell research, telling scientists how better to program stem cells for medical purposes.
Dr. Nir Ohad of Tel Aviv University’s Department of Plant Sciences and Prof. Ralf Reski of the University of Freiburg have discovered a new use for the Polycomb group proteins (PcG) found in moss. They reported their findings recently in the journal Development. PcG proteins play an important role in telling stem cells how to develop, they believe. The research is being funded by the German-Israeli Foundation.
Moss is a kind of plant that shares basic development processes with those found in humans. “We may not have found the switch that turns stem cells into tissue,” comments Dr. Ohad, “but we have found a key component which makes this switch work.”
Stopping the runaway gene
In their new paper, the researchers describe an ancient mechanism that alters the way DNA organizes inside the cell nucleus, which in turn, affects gene expression. This finding has important implications in stem cell therapies, which can go awry if implanted stem cells aren’t reprogrammed properly.
The researchers examined the “central regulatory function” of the PcG complex and how it programs an organism’s development, including the first divisions of cells as a new organism is born. Insights from this research have implications for plant and human development alike, and with time could be applied to cancer research. “As far as we know, there are some instances in cancer where the cellular mechanisms are defective or impaired,” Dr. Ohad says. “When this happens, it can lead to the misregulation of the genetic code, which can then lead to the breakdown of a healthy cell.”
He adds that this “switch,” which ensures the proper development of the organism, emerged early in the evolution of all organisms with a nucleus and organized DNA, long before animals and plants evolved into vastly different species and genera.
Towards a less “moss-ist” world
In some scientific disciplines, mosses are considered “lower-class,” or less advanced, organisms. But Dr. Ohad defends mosses as highly adaptive organisms, which after 450 million years are still with us. “The original moss – Physcomitrella patens – hasn’t endured all these years, but its descendents have,” he says. He adds that the study of the biology of moss is similar to the study of the biology of other ancient creatures, like crocodiles and flies, helping scientists to understand the evolution and function of basic biological mechanisms.
The researchers suggest that the basic function of the PcG mechanism in moss, common to its function in plants and humans, is in regulating cell differentiation, describing the point at which a stem cell “decides” to become a leaf or flower, for example.
“As they develop, stem cells go from having a non-defined function to a specific one,” says Dr. Ohad. “If you don’t know how to manipulate the type of tissue you want to modulate, replace or heal, you might cause the malfunction of another type of tissue.”
According to Dr. Ohad, this research has direct implications for the study of plant biology, providing basic information on how the plant body and reproduction are regulated. It gives science a tool to control tissue specification, timing of reproduction and the development of traits in seeds that serve as the source for human and animal feed.
Source:
George Hunka
American Friends of Tel Aviv University
Mother Nature Gives Clues For Improving Stem Cell Techniques, TAU Scientists Discover
Originally from:
http://www.medicalnewstoday.com/articles/165728.php
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Stem Cell Success Could Help Regenerate Parathyroids
Last Updated on Wednesday, 30 September 2009 02:00 Written by Wednesday, 30 September 2009 02:00
An early laboratory success is taking University of Michigan researchers a step closer to parathyroid gland transplants that could one day prevent a currently untreatable form of bone loss associated with thyroid surgery.
The scientists were able to induce embryonic stem cells to differentiate into parathyroid cells that produced a hormone essential to maintaining bone density. The laboratory results in live cell cultures, published in Stem Cells and Development, need to be tested in further pre-clinical studies.
Parathyroid glands, four glands each the size of a rice grain that lie next to the thyroid in the neck, are easily damaged when surgeons operate on patients with cancerous or benign thyroid tumors. Without their calcium-regulating hormone, patients can develop osteomalacia, a severe form of bone loss similar to rickets that affects tens of thousands of people in the United States with muscle cramps and numbness in the hands and feet.
“We used human embryonic stem cells as a model for ways to work out the recipe to make parathyroid cells,” says Gerard M. Doherty, M.D., chief of endocrine surgery and Norman W. Thompson Professor of Endocrine Surgery at U-M Medical School.
The research illustrates the payoff of rapidly increasing knowledge about how embryonic stem cells give rise to other kinds of cells. That knowledge can be the springboard for influencing other cells to regenerate damaged parts of the body.
Doherty’s team used embryonic stem cells from a Bush administration-approved embryonic stem cell line to test a way to produce functioning, differentiated parathyroid cells to transplant into a patient and restore function.
With the recipe worked out, Doherty’s team anticipates developing a treatment that doesn’t use embryonic stem cells.
“We anticipate taking a person’s own cells and making them into parathyroid cells,” Doherty says. Using the patient’s own cells should eliminate the risk of rejection.
What’s next
Having demonstrated a method for leading embryonic stem cells to produce parathyroid cells, the team hopes to be able to repeat those steps using cells from the patient’s own thymus gland. The method involves no genetic modification of cells, a key goal of Doherty’s team.
“We want to have a process that will allow us to reintroduce cells into the patient’s body safely,” Doherty says.
Any successful treatment in people is five to 10 years away.
Additional U-M authors: Eve L. Bingham, Shih-Ping Cheng, Kathleen M. Woods Ignatoski
Funding: Michigan Center for Human Embryonic Stem Cell Research, U-M Department of Surgery
Citation: Stem Cells and Development, September 2009,18(7): 1071-1080.
Source: University of Michigan Health System
Stem Cell Success Could Help Regenerate Parathyroids
Originally from:
http://www.medicalnewstoday.com/articles/165640.php
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New England Cord Blood Bank Reports Increased Use Of Banked Stem Cells
Last Updated on Tuesday, 29 September 2009 05:00 Written by Tuesday, 29 September 2009 05:00
New England Cord Blood Bank, Inc. (NECBB), a global cord blood processing and storage facility, announced today that the company has seen a consistent and robust increase in the cord blood units being used for transplants within the past few years.
Since 2006, according to NECBB records, the number of banked units used in transplants has doubled. The company attributes this increase in cord blood usage to the ever evolving research surrounding cord blood stem cells.
“We have always reminded parents that stem cell therapies are advancing very quickly and it is difficult to know what the possibilities are. The fact that more parents are using cells they stored suggests that the scope of treatments available is encouraging,” said Dr. David Matzilevich, Chief Scientific Officer of NECBB. “We are confident that the cells found in cord blood are extremely valuable and will only prove to be more so as time goes on.”
Over 80 diseases can be treated with the use of cord blood, including some types of juvenile diabetes and chronic leukemia. Cord blood collection poses no threat to the baby and therefore, circumvents the ethical issues of embryonic stem cells. The cells are taken from the cord after it is cut from the mother and baby.
For over 20 years, cord blood transplants have produced positive results. In 1988, a three-year- old girl received a cord blood transplant to treat Fanconi’s anemia. In 1991, another child was treated for myelogenous leukemia with cord blood stem cells and the transplant was a success. Since then, two-thirds of cord blood transplants performed have been for malignant conditions and overall have shown a high rate of success. The rising numbers of transplants reported by NECBB proves further that the achievements of cord blood banking will only grow.
Due to the success of private cord blood banking, NECBB plans to expand its facility and add a public component to the bank. The company plans to partner with smaller hospitals and private obstetric practices across the state and country to continue banking quality cord blood both publicly and privately, and will continue to be a leading resource for families considering banking their newborn’s cord blood.
Source
New England Cord Blood Bank
New England Cord Blood Bank Reports Increased Use Of Banked Stem Cells
Originally from:
http://www.medicalnewstoday.com/articles/165571.php
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ALS Stem Cell Trial Gets FDA Go Ahead
Last Updated on Tuesday, 29 September 2009 12:17 Written by Tuesday, 29 September 2009 02:00
The US Food and Drug Administration (FDA) said the first clinical trial to test a new stem cell treatment for the fatal neurodegenerative disease
ALS (amyotrophic lateral sclerosis) this month (ALS) can go ahead.
The federal agency gave the green light earlier this month, allowing principal investigator and neurologist Dr Eva Feldman, the DeJong Professor of
Neurology at the University of Michigan (U-M) Medical School to start Phase 1 testing of the safety and efficacy of an investigational new drug
(IND) from Neuralstem, a company based in Rockville, Maryland.
The drug, which comprises the company’s own patented neural stem cells, is administered as a series of injections at different sites along the spinal
cord.
Feldman, who directs the ALS clinic at U-M, and the U-M Program for Neurology Research & Discovery, worked with Neuralstem to develop the
protocol for carrying out the injections.
The trial is expected to take place only at Emory University in Atlanta, Georgia, subject to approval from its Internal Review Board. If the board gives
its approval, the site principal investigator of the trial is expected to be Dr Jonathan Glass, director of Emory’s Neuromuscular Laboratory and also its
ALS Center which has a world-wide reputation.
Feldman told the press earlier this month that they were very excited to be starting the trial:
“This is a major stride forward in what still could be a long road to a new and improved treatment for ALS,” she added.
Feldman explained that ALS is a terrible disease that kills the patient by paralysis. She said work with animals showed that spinal cord stem cells
worked in two ways: they protected motor neurons that were at risk and they also made new connections between them and the neurons controlling
muscles.
“We don’t want to raise expectations unduly,” said Feldman, “but we believe these stem cells could produce similar results in patients with ALS,” she
said.
The trial will study the safety of Neuralstem’s cells and the surgical procedures and devices required for multiple injections of the drug directly into
the grey matter of the spinal cord.
Also known as Lou Gehrig’s disease, ALS affects about 30,000 Americans, with about 7,000 new diagnoses a year. The disease gradually destroys
neurons or nerve cells that control voluntary muscles to the point where eventually patients can’t move or even speak.
There are currently no known treatments that can slow the progression of the disease.
For the first phase of the trial, which is being paid for by the drug company, Feldman and colleagues will be treating 12 of 18 recruited patients with
varying degress of ALS. The 12 patients will receive between five and ten injections of stem cells into the lumbar region of the spinal cord. They will
be examined regularly for up to two years after the operation at which point the data will be reviewed.
If the results are favorable, the drug will still have to undergo Phase II and Phase III trials and then win final FDA approval before the treatment is
available to the public.
Richard Garr, Neuralstem’s CEO and President, told the press that:
“While this trial aims to primarily establish safety and feasibility data in treating ALS patients, we also hope to be able to measure a slowing down of
the ALS degenerative process.”
He declared confidence in Feldman and Glass and their team, saying “there is no better team to conduct this study for us”.
In pre-clinical work Neuralstem’s cells have reportedly extended the life of rats with ALS and reversed paralysis in rats with Ischemic Spastic
Paraplegia (there were two studies about this work, one in collaboration with Johns Hopkins researchers was published in Transplantation in
2006, and the other with researchers at University of California San Diego was published in Neuroscience in 2007.)
Neuralstem said that its patented technology enables for the first time, neural stem cells of the human brain and spinal cord to be made in commercial
quantities, and it also controls the differentiation of the cells into mature, physiologically relevant human neurons and glia cells.
In addition to ALS, the company is hoping to use its new technology to target other major central nervous system diseases such as Ischemic Spastic Paraplegia, Traumatic Spinal
Cord Injury and Huntington’s disease.
In a press statement, U-M said Feldman has no financial interest in or financial arrangement with Neuralstem.
Sources: UMHS Newsroom, Neuralstem.
Written by: Catharine Paddock, PhD
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today
ALS Stem Cell Trial Gets FDA Go Ahead
Originally from:
http://www.medicalnewstoday.com/articles/165528.php
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