Drug approval requires a deep understanding of the mechanism of action

The team of Julia Bandow, who heads the RUB's Junior Research Group Microbial Antibiotic Research, has been studying the MP196 peptide as a representative of a group of very small positively charged peptides that consist of some four to ten amino acids. Earlier studies had shown that MP196 is efficient against various bacteria, including particularly problematic multi-resistant pathogens that frequently cause sepsis. How MP196 kills bacteria remained unclear. However, in order for a new substance to be approved as a drug, its mechanism of action has to be fully understood.

Peptide disrupts cell wall biosynthesis and cell respiration

An international team of astronomers, led by Felipe Braga-Ribas (Observatório Nacional/MCTI, Rio de Janeiro, Brazil), has used telescopes at seven locations in South America, including the 1.54-meter Danish and TRAPPIST telescopes at ESO’s La Silla Observatory in Chile, to make a surprise discovery in the outer Solar System.

A 60,000-year record of rainfall in central Indonesia used sediments from a remote lake reveals important new details about the climate history of a region that wields a substantial influence on the global climate as a whole.

The Indonesian archipelago sits in the Indo-Pacific Warm Pool, an expanse of ocean that supplies a sizable fraction of the water vapor in Earth's atmosphere and plays a role in propagating El Niño cycles. Despite the region's importance in the global climate system, not much is known about its own climate history, says James Russell, associate professor of geological sciences at Brown.

A new paper has found that the chemical citrate – a by-product of natural cell metabolism – is mixed with water to create a viscous fluid that is trapped between the nano-scale crystals that form our bones. This fluid allows enough movement, or 'slip', between these crystals so that bones are flexible, and don't shatter under pressure. It is the inbuilt shock absorber in bone that, until now, was unknown.

If citrate leaks out, the crystals – made of calcium phosphate – fuse together into bigger and bigger clumps that become inflexible, increasingly brittle and more likely to shatter. This could be the root cause of osteoporosis.

A new small, wireless self-contained pacemaker appears safe and feasible for use in patients, according to a small study in the American Heart Association journal Circulation.

Although traditional pacemakers pose minimal risk, patients are still vulnerable to some short- or long-term complications, said Vivek Y. Reddy, M.D., lead author of the study and director of the Cardiac Arrhythmia Service at Mount Sinai Hospital in New York City.

Those complications can stem from the pulse generator implanted under the skin of the chest, where infections or skin breakdown can occur, and particularly from the leads, or wires, that run from the generator through a vein to the heart. Leads can break, dislodge or contribute to a vein blockage.

Bottom Line: Habitually playing violent video games appears to increase aggression in children, regardless of parental involvement and other factors.

Author: Douglas A. Gentile, Ph.D., of Iowa State University, Ames, and colleagues.

Background: More than 90 percent of American youths play video games, and many of these games depict violence, which is often portrayed as fun, justified and without negative consequences.