A case of so-called “mad cow disease” was found in a California dairy cow last week. The disease, known to veterinary scientists as bovine spongiform encephalopathy (BSE), is fatal, and can be transmitted from cow-to-cow or cow-to-human through the ingestion of contaminated tissue. There is no evidence BSE spreads to humans — the human form of the disorder is called Creutzfeldt-Jakob disease — through drinking milk. As such, authorities claim that the infected animal (which is being held and will be destroyed) posed no risk to humans.

Xylitol, or birch sugar, is a sugar naturally found in plums, strawberries, raspberries, and rowan berries. It is often used to sweeten toothpaste and chewing gum since it is as sweet as sucrose but does not cause tooth decay; this is because it cannot be fermented by bacteria that live in our mouths, and instead inhibits their growth. As the key step causing acute ear infections is the colonization of the middle ear by bacteria that move there from the mouth, researchers have hypothesized that xylitol might help prevent acute ear infections as well as tooth decay.

Researchers at the University of Toronto recently performed a meta-analysis of three Finnish studies and found that children who chewed gum — or took other products laden with xylitol, including lozenges or syrup — had about a 25% lower risk of developing an ear infection compared to controls. The study is published in the Cochrane Database of Systematic Reviews [1].

The 2011 Nobel Prize in Physiology or Medicine was announced on Monday. The prize was awarded to three scientists for their work on the body’s immune system.

The prize of 10-million-Swedish-krona (US$1.5-million) was divided, one half jointly to Bruce A. Beutler, age 54, at The Scripps Research Institute, La Jolla, California, and Jules A. Hoffmann, age 70, at the French National Centre for Scientific Research (CNRS) Institute of Cell and Molecular Biology in Strasbourg, for their discovery of receptor proteins that can recognize bacteria and other microorganisms and activate innate immunity, and the other half to Ralph M. Steinman, age 68, at Rockefeller University in New York, for his discovery of dendritic cells of the immune system and their unique capacity to activate and regulate adaptive immunity, the later stage of the immune response during which microorganisms are cleared from the body.

Antibiotic resistance is an ever-growing clinical problem. Four years ago, a study found that antibiotics are overprescribed for sinus infections. Compounding the issue is the fact that as bacteria are learning to tolerate and even circumvent existing classes of antibiotics, not enough work is being done to discover new ones. Combinations or cocktails of antibiotics are often used to broaden the antimicrobial spectrum of each and to achieve synergistic effects; this approach has successfully been applied to combat tuberculosis, leprosy, malaria, and famously, HIV. Yet the discovery of effective combinations has usually been almost fortuitous, most often resulting from trial and error rather than a systematic analysis.

In the current study, researchers systematically examined combinations of 1,057 compounds previously approved as drugs to find those that exhibited synergy with the antibiotic minocycline. Their work is reported in the April 24, 2011 issue of the journal Nature Chemical Biology [1]. The compounds were chosen because they have already been approved as drugs, they are known to have activity in vivo and are known to be relatively safe. Many approved drugs are known to have utility for clinical indications other than those for which they initially received approval. Moreover, using pre-approved compounds also reduces the time and cost associated with developing new compounds for therapeutic use.