Another One Bites the Dust
First there was smallpox, eradicated after a long global campaign. Now there's rinderpest, the second disease to be wiped off the face of the planet.
Never heard of it? Not surprising ... it affects cattle. Afflicted animals develop fever and inflammation of the digestive tract, which rapidly leads to death. Up to 95% of herds can die.
But while people don't catch the disease, it is hardly without implications for us. Historically, the death of cattle was often followed by the death of their owners – quickly because of lack of meat and milk or more slowly because plowing and other farm work dependent on cattle could not be done.
The virus has been blamed at least in part for such things as the fall of the Roman Empire and the French Revolution. Now, the United Nations said this week, a $5-billion, decades-long global campaign has consigned the rinderpest virus itself to history.
An ointment containing glyceryl trinitrate (nitroglycerin) may give people bitten by venomous snakes a better chance at survival, according to a study in Nature Medicine.
Nitric oxide slows the intrinsic lymphatic pump, which is integral to moving snake venom through the lymphatic system into the bloodstream after a bite. Glyceryl trinitrate is a nitric oxide-releasing agent.
Australian researchers found that an ointment containing the drug slowed the movement of snake venom through the lymphatic system of rats and improved survival time. In humans with a simulated snakebite on the foot, the ointment slowed foot-to-groin transit time from 13 to 54 minutes.
"These results point to a new method of snakebite first aid that may also be useful for bites to the torso or head," wrote the researchers, who noted that snakebite accounts for about 100,000 deaths and 400,000 amputations worldwide each year.
Bisphosphonate Side Effect: Milder Flu
A standard osteoporosis drug might help fight off flu infections, in vitro and animal studies have suggested.
According to researchers from the University of Hong Kong, the bisphosphonate drug pamidronate (Aredia) activates and expands the gamma-delta T-cell subset. These cells recognize and kill host cells infected with flu viruses, helping the body rid itself of the infection.
Tests in mice, reported in the Journal of Experimental Medicine, indicated that treatment with pamidronate reduced the severity of infections caused by the pandemic H1N1 "swine" flu and H5N1 and H9N2 avian flu viruses.
The strategy is especially attractive because it doesn't target the flu virus itself and therefore should be effective against a wide range of them without engendering resistance.
Also, the researchers suggested, pamidronate could be distributed quickly during a sudden pandemic, long before strain-specific vaccines could be produced.
Who Turned Out the Lights?
Late-day anxiety and agitation seen in some institutionalized seniors may have a biologic basis involving one or more behavior-associated proteins, studies of mice suggest.
Older animals that exhibited signs of the so-called "sundowning" phenomenon had increased production of acetylcholinesterase in the hours leading up to sleep time as compared with younger mice. The older mice also had increased expression of choline acetyltransferase and c-Fos, both of which have associations with behavioral disturbances.
When evaluated for anxiety-like behaviors at different times of the day, younger mice showed consistent levels of anxiety when placed in stressful situations. In contrast, older mice exhibited greater agitation and anxiety when tested late in the day.
Transgenic mice producing amyloid precursor protein, a model for Alzheimer's disease, also were more anxious and agitated late in the day compared with wild-type animals, as reported online in Proceedings of the National Academy of Sciences.
"All of these results converge to suggest there are changes in the cholinergic systems of aged mice that may be contributing to the anxiety and agitation symptoms that we documented," Tracy Bedrosian, of Ohio State University in Columbus, said in a statement.
Taking a molecular red pen to sections of the DNA code scrambled by the mutations that cause hemophilia appears to restore clotting function, researchers found in a mouse model.
Sending in zinc finger nucleases to break through the double strand at a specific target location allowed gene replacement by a vector administered at the same time in mice with hemophilia B in the study.
The edited genes functioned well enough to correct clotting times in the mice, "raising the possibility of genome editing as a viable strategy for the treatment of genetic disease," according to a report in Nature from researchers at Children's Hospital of Philadelphia and elsewhere.
What One Stem Cell Can Do
Newly discovered properties of stem cells in the brain may provide a way of regenerating neural capacity in the aging or diseased brain, according to a team of researchers from Johns Hopkins University School of Medicine writing in Cell.
In an effort to trace the family tree of the neural stem cell, the researchers developed novel genetic-marking technique for tracking individual radial glia-like precursors in genetically modified mice with color-coded cells.
Using clonal analysis and long-term lineage tracing, they found that the color-coded radial glia-like cells in the mouse brain were able to continue replicating themselves and differentiating into multiple different progenitor cells for as long as a year.
"If we can somehow cash in on this newly discovered property of stem cells in the brain, and find ways to intervene so they divide more, then we might actually increase their numbers instead of losing them over time, which is what normally happens, perhaps due to aging or disease," said lead author Hongjun Song, PhD.