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U-M researchers dispute widely held ideas about stem cells

ANN ARBOR, Mich.--- How do adult stem cells protect themselves from accumulating genetic mutations that can lead to cancer?

For more than three decades, many scientists have argued that the "immortal strand hypothesis" - which states that adult stem cells segregate their DNA in a non-random manner during cell division -- explains it. And several recent reports have presented evidence backing the idea.

But in this week's issue of the journal Nature, University of Michigan stem cell researcher Sean Morrison and his colleagues deal a mortal blow to the immortal strand, at least as far as blood-forming stem cells are concerned.

They labeled DNA in blood-forming mouse stem cells and painstakingly tracked its movement through a series of cell divisions. In the end, they found no evidence that the cells use the immortal-strand mechanism to minimize potentially harmful genetic mutations.

"This immortal strand idea has been floating around for a long time without being tested in stem cells that could be definitively identified. This paper demonstrates that it is not a general property of all stem cells," said Morrison, director of the Center for Stem Cell Biology at the U-M Life Sciences Institute.

It remains possible that stem cells in other tissues use this process.

Full story.

Engineers perfecting hydrogen-generating technology

WEST LAFAYETTE, Ind. - Researchers at Purdue University have further developed a technology that could represent a pollution-free energy source for a range of potential applications, from golf carts to submarines and cars to emergency portable generators.

The technology produces hydrogen by adding water to an alloy of aluminum and gallium. When water is added to the alloy, the aluminum splits water by attracting oxygen, liberating hydrogen in the process. The Purdue researchers are developing a method to create particles of the alloy that could be placed in a tank to react with water and produce hydrogen on demand.

The gallium is a critical component because it hinders the formation of an aluminum oxide skin normally created on aluminum's surface after bonding with oxygen, a process called oxidation. This skin usually acts as a barrier and prevents oxygen from reacting with aluminum. Reducing the skin's protective properties allows the reaction to continue until all of the aluminum is used to generate hydrogen, said Jerry Woodall, a distinguished professor of electrical and computer engineering at Purdue who invented the process.

Full article.

Medical College Receives $1.5 Million NIH Grant to Improve Outcomes of BMT for Leukemia Patients

The Medical College of Wisconsin has received a $1.5 million, four-year grant from the National Heart, Lung, and Blood Institute to continue studies designed to improve outcomes after allogeneic (donor) bone marrow transplantation (BMT).

William Drobyski, M.D., professor of medicine in neoplastic diseases and related disorders and professor of pediatrics, is lead investigator for the study.

"One of the ways that allogeneic bone marrow transplantation is able to cure patients of their leukemia is through a graft versus leukemia (GVL) effect, which is an immunological reaction of the donor's bone marrow cells against the underlying leukemia," said Dr. Drobyski. "Unfortunately, this beneficial GVL effect is typically associated with graft versus host disease (GVHD), which is the major cause of morbidity and mortality after allogeneic BMT."

In this project, Dr. Drobyski and his colleagues will examine the interrelationship between the GVL effect and GVHD. Their method involves testing several strategies designed to separate the beneficial GVL effect from the damaging effects associated with GVHD. Their hope is that pre clinical findings in these studies can someday be translated into novel transplantation approaches for treatment of leukemia.

When is a stem cell not really a stem cell?

Working with embryonic mouse brains, a team of Johns Hopkins scientists seems to have discovered an almost-too-easy way to distinguish between “true” neural stem cells and similar, but less potent versions. Their finding, reported this week in Nature, could simplify the isolation of stem cells not only from brain but also other body tissues.

What the researchers identified is a specific protein “signal” that appears to prevent neural stem cells – the sort that might be used to rebuild a damaged nervous system – from taking their first step toward becoming neurons. “Stem cells don’t instantly convert into functional adult tissue,” says author Nicholas Gaiano, Ph.D., assistant professor at the Institute for Cell Engineering. “They undergo a stepwise maturation where they gradually shed their stem cell properties.”

The first step turns stem cells into “progenitor” cells by dictating how signals downstream of a protein called Notch, which regulates stem cells in many different tissues, are transmitted. One well known target of Notch is a protein called CBF1. To help study Notch signaling further, Gaiano and his team created genetically engineered mouse embryos that glow green when CBF1 is turned on.

To their surprise, they noticed that during brain development some of the brain cells generally thought to be neural stem cells stopped glowing, indicating that the CBF1 protein was no longer active in them. A closer look revealed that those cells that went dark were in fact no longer true neural stem cells, which can form all major brain cell types, but instead had aged into progenitor cells, which form mostly neurons.

They tested whether CBF1 was the critical switch by chemically knocking out the protein in neural stem cells. The knockout got the stem cells to rapidly convert to progenitor cells. “However, if we activated the CBF1 protein in progenitor cells we couldn’t get them to shift back into stem cells,” says Gaiano. “So whatever happens biochemically once CBF1 is turned off seems to create a one-way street.”

Another recent study, using the mouse line generated by the Gaiano group, found that CBF1 signaling may play the same role in blood stem cells, leading Gaiano to suspect that his team’s discovery might be a general “switch” distinguishing stem cells from progenitors in many different tissues.

Continue reading "When is a stem cell not really a stem cell?" »

Photon-transistors for the supercomputers of the future

Scientist from the Niels Bohr Institute at University of Copenhagen and from Harvard University have worked out a new theory which describe how the necessary transistors for the quantum computers of the future may be created. The research has just been published in the scientific journal Nature Physics.

How to build a supercomputer

Researchers dream of quantum computers. Incredibly fast super computers which can solve such extremely complicated tasks that it will revolutionise the application possibilities. But there are some serious difficulties. One of them is the transistors, which are the systems that process the signals.

Today the signal is an electrical current. For a quantum computer the signal can be an optical one, and it works using a single photon which is the smallest component of light.

“To work, the photons have to meet and “talk”, and the photons very rarely interact together” says Anders Søndberg Sørensen who is a Quantum Physicist at the Niels Bohr Institute. He explains that light does not function like in Star Wars, where the people fight with light sabres and can cross swords with the light. That is pure fiction and can’t happen. When two rays of light meet and cross, the two lights go right through each other. That is called linear optics.

What he wants to do with the light is non-linear optics. That means that the photons in the light collide with each other and can affect each other. This is very difficult to do in practice. Photons are so small that one could never hit one with the other. Unless one can control them – and it is this Anders Sørensen has developed a theory about.

Full story.

Robotic surgery: UW doctor uses 'da Vinci' to heal

Anita Weier

Three-fourths of cancerous prostate removal surgeries at the University of Wisconsin Hospital are now performed by a robot.

The robot and its very flexible "wrists" are controlled by a surgeon, however.

The first robotic prostatectomy at UW Hospital was performed in March 2006 by urologic surgeon Dr. David Jarrard, who also performed the 200th on July 31 this year.

Full story.

Neurognostics Releases fDAD™ - Version 2.0

Includes Upgraded Workflow Software and Expanded Stimulation Paradigm Library

August 21, 2007

(Milwaukee, WI) - Neurognostics, a Milwaukee-based medical imaging company, has released Version 2.0 of its Functional Data Acquisition Device (fDAD™). This release enhances a user's ability to acquire functional MRI (fMRI) data and includes upgraded fMRI workflow software and numerous additions to Neurognostics' extensive library of ready-to-use fMRI stimulation paradigms.

fDAD™ Version 2.0 incorporates new features and improvements that add functionality to the original Version 1.0 software platform. This easy-to-use fMRI application tool accommodates a variety of functional imaging backgrounds and uses a step-by-step process to standardize the acquisition of fMRI data. Featuring the ability to incorporate an assortment of customized visual stimulation choices, Neurognostics' newly released fDAD™ easily integrates into existing MRI room environments and standardizes the process of acquiring fMRI data.

Continue reading "Neurognostics Releases fDAD™ - Version 2.0 " »

Scientists hail ‘frozen smoke’ as material that will change world

A MIRACLE material for the 21st century could protect your home against bomb blasts, mop up oil spillages and even help man to fly to Mars.

Aerogel, one of the world’s lightest solids, can withstand a direct blast of 1kg of dynamite and protect against heat from a blowtorch at more than 1,300C.

Scientists are working to discover new applications for the substance, ranging from the next generation of tennis rackets to super-insulated space suits for a manned mission to Mars.

Full story.

Light seems to defy its own speed limit

It's a speed record that is supposed to be impossible to break. Yet two physicists are now claiming they have propelled photons faster than the speed of light. This would be in direct violation of a key tenet of Einstein's special theory of relativity that states that nothing, under any circumstance, can exceed the speed of light.

Günter Nimtz and Alfons Stahlhofen of the University of Koblenz, Germany, have been exploring a phenomenon in quantum optics called photon tunnelling, which occurs when a particle slips across an apparently uncrossable barrier. The pair say they have now tunnelled photons "instantaneously" across a barrier of various sizes, from a few millimetres up to a metre. Their conclusion is that the photons traverse the barrier much faster than the speed of light.

Full story (available after August 18, 2007 from New Scientist)


Medical College of Wisconsin & Children’s Research Institute Establish New National Pediatric Kidney Disease Research Center With Translational Research Focus to Expedite Bench to Bedside Cures

The National Institutes of Health (NIH) has awarded $4.6 million over the next five years to the Medical College of Wisconsin to establish a Research Center of Excellence in Pediatric Nephrology at Children’s Research Institute. As one of only two such Centers in the country, it will build on current groundbreaking research programs at the College and Children’s Research Institute, expediting new and exciting treatments for thousands of children with genetic, acquired or progressive kidney disease.

“This new Center of Excellence designation will enhance our ability to implement our translational research program, where research and clinical care are fully integrated,” said Ellis D. Avner, M.D., principal investigator of the program and director of Children’s Research Institute. Dr. Avner is a professor of pediatrics, and associate dean for research at the Medical College.

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