Stem Cells

This week, the New York Times published a nice profile on Nobel Laureate Martin Chalfie at Columbia University. Chalfie shared the Nobel Prize in Chemistry last year for his work on an amazing protein found in jellyfish called Green Fluorescent Protein, or GFP. The article is a great reminder of how very basic research on jellyfish and worms, of all things, yields invaluable scientific tools and knowledge.

GFP has the natural property of absorbing invisible ultraviolet light and producing green light – a discovery made in 1961 by Osamu Shimomura (who also shared the 2008 Nobel Award with Roger Tsien and Chalfie).

Chalfie’s “aha” moment, in 1989 at a department seminar, was a recognition that the light-producing properties of GFP could be harnessed as a sort of molecular flashlight. (Read more…)

Researchers in the United Kingdom have succeeded in coaxing human embryonic stem cells into becoming sperm. Though the process is inefficient and there is some debate over whether the sperm are fully developed, this work will hopefully lead to a much-needed experimental system for understanding the biology of sperm development.

The more controversial and longer-term outcome, as suggested by the lead researcher, Dr. Karim Nayernia, is that stem cells might one day be used to generate sperm as a treatment for male infertility.

It’s worth pointing out that the same researcher accomplished a similar feat in 2006 using mouse embryonic stem cells to produce mouse sperm.  Only in this case, the experiment was taken one step farther – the sperm were injected into mouse eggs.  Though the mothers gave birth to live pups, they suffered from many abnormalities. All died within 5 months.

This example illustrates the technical and ethical challenges in moving reproductive technologies from the lab to the clinic. There really isn’t an easy path. It also should serve as a reminder that the United States needs to address the relative vacuum in efficacy, safety, and ethical oversight for the rapidly developing field of reproductive technology (a ~$10 billion/yr industry).

In the UK, reproductive technologies are closely regulated at the federal level by a governing body known as the Human Fertilisation and Embrology Authority (HFEA). The UK has carefully crafted rules on the research and clinical use of gametes (sperm/eggs), human cloning, genetic technologies as applied to human embryos or gametes, etc. In this case, any procreative use of sperm created from stem cells is prohibited.

In the United States there are few rules. The practice of medicine, by and large, is regulated at the state level. Our federal government leaders have been unwilling to call for a national discussion on implementing uniform rules for gamete donation, embryo creation, research, storage, etc. (a report from the 2004 Presidential Council on Bioethics notwithstanding). In fact, when Canada passed its Assisted Human Reproduction Act in 2004, it left the United States as one of the few developed nations without a national policy.

The result has been lax medical oversight, introduction of new technologies without sufficient studies on safety, and a piecemeal collection of rules.

The progress coming from the UK reminds us that we need to have a national discussion soon.

An inspiring segment on last night’s episode of 60 Minutes profiled the work of DARPA’s (Defense Advanced Research Projects Agency) “Revolutionizing Prosthetics” program, a $100 million project intent on advancing a field that, in some respects, hasn’t changed much in more than 50 years.

The piece concentrated on the DARPA-funded DEKA arm, developed by inventor Dean Kamen and his team of 40 engineers. Size and comfort were key issues in designing the limb. The final product is the size of an average person’s arm, weighs around nine pounds, and is buffered from the wearer’s body by small balloons that expand and deflate as pressure on the arm changes (the balloons inflate when the wearer picks up something heavy, and deflate when the arm is at rest).  Controlling the arm using their shoulders and pedals in a specially designed shoe, volunteers demonstrated their ability to pick up and drink from a soda bottle and eat a grape.

The end of the segment touched on the future of prosthetic control, featuring Duke University engineer Jonathan Kuniholm. Kuniholm, who lost his forearm in Irag, demonstrated his ability to control a prosthetic hand using the nerves still intact in the remaining part of his arm. These nerves send out small electrical signals, which a processor in a prosthetic arm can be trained to interpret.

Similar work is being done here by Northwestern faculty member Todd Kuiken and his research team at the Rehabilitation Institute of Chicago. They are using an exciting new procedure called targeted reinnervation to reroute nerves that used to control a missing limb to different, intact muscle areas (rerouting nerves that used to control an amputee’s arm to his or her chest muscles, for example). These reinnervated muscles can then communicate with a prosthesis, again allowing the wearer to control their limb intuitively. Click here to read an SiS article on the Kuiken team’s work.

According to BBC News, testing is currently underway for a treatment of stem cells that can be injected directly into the body and guided to damaged points via magnets and guiding magnetic nanoparticles in the blood stream. By injecting the magnetic nanoparticles into the stem cells, the researchers at Keele University are able to move the stem cells anywhere in the body, solving the problem of how to focus the regenerative aspects of the cells. (Read more…)

I have to say – a fresh spring breeze is in the air.  Yesterday Barack Obama rescinded an eight-year moratorium on federal funding for embryonic stem cell research. Now, some of the most promising opportunities for treating or even curing diseases like Parkinson’s and diabetes can move forward with federal support and oversight. (Read more…)

On Monday, President Barack Obama  lifted a nearly 8-year ban on the use of federal funds for embryonic stem cell research. The ban was enacted by former president George W. Bush, limiting researchers to a small number of stem cell lines created prior to August, 2001.

The lifting of federal restrictions on stem cell research is being heralded in the scientific community.  Federal funds from agencies like the National Institutes of Health are one of the primary engines of basic research leading to medical and healthcare breakthroughs. Most experts expect the pace of stem cell research to increase significantly, though the promise of treatments or cures is still years away. The first human trial of a spinal cord injury therapy derived from embryonic stem cells was just approved by the FDA in January.

Not only will there be new funding available for stem cell research, but those researchers who relied on state or private dollars to fund their stem cell research programs during the ban will no longer have to run duplicate labs or facilities to separate their privately-funded research from that which was federally funded.

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According to the BBC News, a recent study conducted by a US and Canadian team has managed to “manipulate human skin cells to act like embryonic stem cells.” This is very exciting news, with importance both to the scientific community and to the average person in need of medical treatment. (Read more…)

In a manner of speaking, yes.  A story in this past Sunday’s Chicago Tribune described a California company’s use of stem cells to treat a variety of pet ailments. For $3,000, VetStem, a California biotech company, will process a sample of ordinary fat from your ailing pet (collected by your veterinarian) and return a therapy enriched in the animal’s own stem cells. These cells are then injected into the site of injury – an injured leg, hip joint, or muscle. (Read more…)

As a freshman chemistry major at Northwestern University, I’ve so far been rather dazzled by the scholarship that takes place around me. My professors are the creators of wonder drugs and the authors of textbooks. In other words, the work they do contributes visibly to the progress of the human race. Part of the reason I’ll be blogging for Science in Society is that I’m excited by the fact that every day we hear about an amazing new development coming from the scientific community. New breakthroughs are constantly emerging, revolutionary treatments for the ailments that have plagued humanity for centuries are discovered at a prodigious rate, and products making use of recently-developed technologies hit the shelves all the time. The research that goes on at universities such as Northwestern is partially responsible for this type of progress.

However, we must not forget that a huge portion of the money put toward research comes from government coffers. (Read more…)

The Food and Drug Administration recently approved the first drug to be biologically produced from genetically modified livestock. The drug antithrombin, a protein which helps prevent blood clotting, will be produced by goats that have been genetically modified with the human version of the gene.

Cleverly, researchers spliced the gene in a specific part of the goat genome so that the goats would only produce the protein in their milk. It’s relatively straightforward to isolate the protein drug from other milk proteins and package it for market.

Given that the “bio-pharming” approach has been discussed for decades, it will be interesting to see if the promises of cheaper and higher quality drugs come true.

However, some animal rights groups have expressed concern about the use of animals for drug production. Other groups are concerned about monitoring these transgenic animals, so that they do not enter the food supply.

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