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Archive - Nov 5, 2013

Study Links Intestinal Bacteria to Rheumatoid Arthritis

Researchers have linked a species of intestinal bacteria known as Prevotella copri to the onset of rheumatoid arthritis, the first demonstration in humans that the chronic inflammatory joint disease may be mediated in part by specific intestinal bacteria. The new findings by laboratory scientists and clinical researchers in rheumatology at the New York University (NYU) School of Medicine add to the growing evidence that the trillions of microbes in our body play an important role in regulating our health. Using sophisticated DNA analysis to compare gut bacteria from fecal samples of patients with rheumatoid arthritis and healthy individuals, the researchers found that P. copri was more abundant in patients newly diagnosed with rheumatoid arthritis than in healthy individuals or patients with chronic, treated rheumatoid arthritis. Moreover, the overgrowth of P. copri was associated with fewer beneficial gut bacteria belonging to the genera Bacteroides."Studies in rodent models have clearly shown that the intestinal microbiota contribute significantly to the causation of systemic autoimmune diseases," says Dan R. Littman, M.D., Ph.D., the Helen L. and Martin S. Kimmel Professor of Pathology and Microbiology at NYU School of Medicine and a Howard Hughes Medical Institute investigator. "Our own results in mouse studies encouraged us to take a closer look at patients with rheumatoid arthritis, and we found this remarkable and surprising association," says Dr. Littman, whose basic science laboratory at NYU School of Medicine's Skirball Institute of Biomolecular Medicine collaborated with clinical investigators led by Steven Abramson, M.D., senior vice president and vice dean for education, faculty, and academic affairs; the Frederick H.

“Zone in with Zon”—Aptamers May Be Superior to Antibodies

Dr. Gerald Zon’s latest “Zone in with Zon” blog post, dated November 4, 2013, and published by TriLink BioTechnologies of San Diego, suggests that aptamers may actually be superior to Mother Nature’s antibodies. Dr. Zon said that aptamers were first discovered approximately 20 years ago and are nucleic acids or peptides that bind to a specific target molecule. RNA or DNA aptamers are usually created from a large pool (library) of random sequences. However, he also pointed out that natural RNA aptamers exist in riboswitches. Dr. Zon noted that aptamers have “been used for an impressively wide variety of applications in either basic research or, especially, health-related diagnostics and therapeutics. This remarkable utility is clearly reflected in the publication statistics—since their discovery in 1990, there have been ~11,000 publications indexed to DNA or RNA aptamers in SciFinder with a projected average rate of ~5 per day in 2013! More than 1,600 of these publications are patents, which is a stunning testament to the commercial potential of aptamers.” Dr. Zon went on to describe how in 1990, two independent laboratories separately described different methods for RNA selection, without using an RNA replicase. One method was published in Science by Drs. Craig Turk and Larry Gold, and the other was published in Nature by Drs. Andrew D. Ellington and Jack W. Szostak Dr. Zon went on to note that the vast body of literature covering basic research and numerous applications of nucleic acid aptamers is a stunning testament to the enabling power of these molecules, and to the myriad of expanded types of aptamers and aptamer-generation methods.

How Pigeons May Smell Their Way Home

Homing pigeons, like other birds, are extraordinary navigators, but how they manage to find their way back to their lofts is still debated. To navigate, birds require a ‘map’ (to tell them home is south, for example) and a ‘compass’ (to tell them where south is), with the sun and the Earth’s magnetic field being the preferred compass systems. A new paper provides evidence that the information pigeons use as a map is in fact available in the atmosphere: odors and winds allow them to find their way home. The results were published online on November 4, 2013 in Biogeosciences, an open-access journal of the European Geosciences Union (EGU). Experiments over the past 40 years have shown that homing pigeons get disoriented when their sense of smell is impaired or when they don’t have access to natural winds at their home site. But many researchers were not convinced that wind-borne odors could provide the map pigeons need to navigate. Now, Dr. Hans Wallraff of the Max Planck Institute for Ornithology in Seewiesen, Germany, has shown that the atmosphere does contain the necessary information to help pigeons find their way home. In previous research, Dr. Wallraff collected air samples at over 90 sites within a 200 km radius around a former pigeon loft near Würzburg in southern Germany. The samples revealed that the ratios among certain ‘volatile organic compounds’ (chemicals that can be a source of scents and odors) in the atmosphere increase or decrease along specific directions. “For instance, the percentage of compound A in the sum A+B or A+B+C+D increases the farther one moves from north to south,” Dr. Wallraff explains. These changes in compound ratios translate into changes in perceived smell. But a pigeon that has never left its loft does not know in what directions what changes occur – unless it has been exposed to winds at its home site.