Whole brain radiation therapy costs mice some of their cognitive abilities, but treatment with low-oxygen air revives their reasoning skills.
Whole brain radiation therapy, which is used to destroy metastatic or hard-to-reach brain tumors, comes with a cost: brain tissue damage and the loss of some cognitive abilities. But publishing today (January 18) in PLoS ONE, researchers found that, after irradiating the healthy brain tissue of mice, reducing the amount of oxygen in their environment helped them regain the ability to perform spatial reasoning tasks.
“I believe this paper provides a first important step” in understanding how radiation affects the brain, neuroscientist Gabriel Haddad from the University of California, San Diego, who was not involved in the research, wrote in an email to The Scientist. “But we will need to really know how hypoxia is rescuing the phenotype before this could be at all translational,” he added.
Around 40-50 percent of survivors of whole brain radiation therapy have permanent loss of memory and learning disabilities, but little is known about the mechanism behind this decline. Neuroendocrinologist William Sonntag of the University of Oklahoma College of Medicine and his colleagues had a relatively simple theory: that radiation destroys arteries, capillaries, and other vasculature, prevents them from growing back, and thus kills brain cells by cutting off their oxygen supply.
Read more: Low Oxygen Saves Irradiated Brain? — The Scientist
The EU high court is seeing several cases in the coming months about how patents apply to combination products: do you need to have all items patented? What kind of exclusivity are you granted? I wrote about it for Nature Medicine:
Time is money, and that is what makes the lag between the filing of a patent application for a drug and the date it hits the market so painful for companies to endure. To make up for the wait, in 1992 the EU introduced ‘supplementary patent certificates’ (SPCs), which can grant up to five years of additional market exclusivity after the underlying patent of a medicine expires. Now, after two recent rulings in the EU, experts warn that drugmakers should plan more carefully when seeking SPCs for combination drugs, which can be complicated because these products often contain ingredients beyond those covered by a company’s patents.
When it comes to combination drugs, SPC approval guidelines have varied from country to country in the EU—something that companies have not been too happy about. The law creating the SPC framework “was a very short piece of legislature that caused a huge number of problems,” says Robert Stephen, head of patent prosecution at the London law firm Olswang. But on 24 November, the Court Justice of the European Union (CJEU) handed down decisions on two cases, clarifying how countries across the EU should apply SPCs to combination products.
Read more: EU court gets tough on patent extensions for combo products — Nature Medicine
Starting tomorrow, I’m going to be a weekend editor for CBS’s green tech blog SmartPlanet, covering greentech, medical technology, architecture, and whatever else I can squeeze in there. Read what I’ve covered here.
Genomic sequencing gets cheaper by the day; is it worth it to cut corners and sequence less of the genome when prices are dropping so rapidly?
Less than half of the more than 7,000 heritable diseases identified thus far have a known genetic origin. So, on 6 December, to help pinpoint the DNA glitches behind these disorders and thereby hasten diagnosis and drug development, the Bethesda, Maryland–based US National Human Genome Research Institute (NHGRI) and National Heart, Lung, and Blood Institute announced the funding of the Mendelian Disorders Genome Centers Program, part of a larger bundle of genomics grants totaling more than $400 million toward projects it has also supported in the past.
The nearly $50 million injected into the new Mendelian Disorders program over four years will go to four top genomics institutes in the US—the University of Washington in Seattle, Yale University in New Haven, Connecticut, and the joint genomics center from John Hopkins University in Baltimore, Maryland and the Baylor College of Medicine in Houston. These centers, which together already hold sequence data for around 12,000 individuals with more than 700 disorders, will add even more sequences, predominantly focusing on people’s exons, the protein-encoding regions of the genome. The target diseases might run the gamut from more common diseases, such as heart muscle disorders, to rare diseases that only affect a few people, such as premature aging.
Read more: New NIH genetics center focuses its lens on exome, despite doubts — Nature Medicine
… is definitely worth checking out. It’s a great cheat sheet for the year in medicine: notable people, events, drug developments, retractions. I threw together the intro and the drug progress overview for the issue.
In a year of global political and economic volatility, the waters of biomedicine have stayed relatively calm. No ‘occupiers’ pitched tents in hospital hallways, no major scientific leaders have been overthrown and chased abroad, and, although funding from the US National Institutes of Health has remained flat since 2004, at least it’s not dipping as low as the stock market on bad trading days. In fact, there might even be some reason to celebrate: as Nature Medicine went to press, the US Food and Drug Administration had approved 29 new drugs in the 2011 calendar year, the highest number in the past six years.
But this ship has rocks to dodge yet. The end of 2011 witnessed two blockbuster drugs falling off the so-called ‘patent cliff’, and more medicines hang on by a finger, including the blood thinner Plavix (clopidogrel), made by Sanofi and Bristol-Myers Squibb, and Pfizer’s Viagra (sildenafil) for impotence, both scheduled for generic manufacturing next year. And, in June 2012, the US Supreme Court is slated to weigh in on whether the federal government can mandate that all citizens pay for insurance—a requirement that anchors President Barack Obama’s healthcare bill. The effects of that ruling will ripple out to affect drug pricing and revenue, though the jury is still out on exactly on how.
Before we walk the plank into 2012′s circling sharks, let’s take a breather and review this past year while the fish are still biting and the sun is out.
Read more: Nature Medicine’s End of Year roundup
Growing up, my friend had diabetes and always had to prick herself during the snow day to take care of her illness. So I was pretty amazed when I heard that one-weekly injections were in the works! I wrote about them here.
The announcement last month that drugmakers Amylin Pharmaceuticals and Eli Lilly were parting ways is only the latest twist in their more than two-year quest for regulatory approval of their once-weekly injectable diabetes medication, Bydureon. The companies first filed for approval with the US Food and Drug Administration (FDA) in May 2009, and in the intervening period they have had to deal with two complete response letters for manufacturing issues and potential heart problems. But with new trial data in the bank and Bydureon’s European approval in June, things are looking up, and a decision is expected from the FDA by 28 January.
“I think that the FDA will very likely approve Bydureon,” says senior biotechnology analyst Thomas Wei of the investment firm Jefferies in New York. “And a big part of the reason I think that this will be successful is that the efficacy looks very good.”
Read more: Class of once-weekly diabetes drugs poised for approval — Nature Medicine
Research suggests that HIV transmission is actually elevated when it’s in semen because the virus is able to take advantage of proteins to help it migrate between partners. Some other researchers disagree.
A protein found in semen makes HIV’s job of infecting immune cells easier, according to research published today in Cell Host & Microbe. The proteins, called semenogelins (SEMs), are abundant in semen and carry a positive charge that helps to bring the negatively-charged HIV virus and target immune cells together.
“The unique part of these studies is that they are actually identifying what can increase infection,” said Charu Kaushic, an immunologist at McMaster University who was not involved with the research. “Technically, it’s a very solid paper, but does this actually happen in the genital tract of women post-ejaculation? I’m not sure if it’s physiologically relevant.”
Read more: Semen Protein Boosts HIV Transmission — The Scientist
This story spun off the question, ‘how many medicines could you pack into one pill, max?’
The 1960s cartoon The Jetsons envisioned a future where single pills provided the same nutrition, taste and satiation as food that required chewing. That time-saving tablet remains a pipe dream, but the drugmaker Gilead is trying to deliver a similarly inspired pill for HIV medicines. On 27 October, the California company submitted an application to the US Food and Drug Administration (FDA) for its four-in-one HIV pill, which, if approved, would contain more medicines than any pill currently on the US market. The so-called ‘Quad’ pill promises the same virus-controlling ability as the four drugs separately but should be easier to use for people with the infection.
The idea of combining multiple medicines is seen by some as an easy shortcut to reinvigorating old products. Drugmakers can often simply repackage what’s already on the market, and, because the individual components have already been approved, the hassle of large clinical trials is off the table. The FDA generally requires only simple bioequivalence tests to ensure that drug dosing is consistent with the individual medicines, and, at most, a small human trial to prove similar efficacy.
Read more: Four-in-one HIV pill may be exception among combination drugs — Nature Medicine
New research suggests that long-distance regulators of gene expression — proteins that clip onto your DNA and open up or block a gene — may have caused our human brains to evolve rapidly.
Scientists and philosophers alike have long grasped for the essence that makes humans human, and one answer lies in the brain. Specifically, human brains express genes in different patterns than those of related species, but what causes those changes is unknown. Comparing gene expression in three primate species—human, chimpanzee, and the rhesus macaque—across post-natal development, researchers, publishing today(December 6) in PLoS Biology, found that the most drastic expression changes are found in genes that are controlled at a distance by trans regulators, instead of locally by cis regulators.
“The authors here found a new explanation for how this evolution of the advanced human brain occurred at the molecular level,” said Henrik Kaessmann, who studies genomic evolution at the University of Lausanne in Switzerland and was not involved in the research. “It’s a very interesting message: that functionally relevant changes tend to be more trans driven.”
Despite the minute genetic differences between human brains and their primate relatives, Homo sapienscognitive ability is significantly more advanced, enabling us to “make complicated tools, come up with complicated culture and colonize the world,” said lead author Mehmet Somel, a postdoc studying human evolutionary genomics at the University of California, Berkeley. Because humans spend more than a decade developing into adults and learning, far more than the two or three years of chimpanzee adolescence, researchers have long suspected that developmental genes are involved in human brain evolution. “And the idea that brain gene expression profiles might be different between species was proposed 40 years ago,” Somel added.
Read more: Brain Evolution at a Distance — The Scientist
Image: FLICKR, GREENFLAMES09
