Microbiology

All cells are surrounded by protective, fatty membranes.In the cell membrane there are thousands of membrane proteins that transport nutritional substances, ions, and water through the membrane. Membrane proteins are also necessary for cells to recognize each other in the body and for a nervous system, for example, to be formed. Researchers at Stockholm University report in Nature that they have now managed to reveal the "molecular code" that governs the insertion of proteins in the cell membrane. About 25 percent of all proteins in a cell are found in the cell membrane. Since they regulate…

A bioprospecting expedition to Iceland’s famed hot springs has yielded new strains of bacteria with potential of producing hydrogen and ethanol fuels from wastewater now discharged from factories that process sugar beets, potatoes and other plant material. The microbes hold potential for combining energy production with wastewater treatment, according to a report on the discovery scheduled for the Jan./Feb. issue of ACS’ Energy & Fuels. In the study, Perttu E. P. Koskinen and colleagues point out that ethanol and hydrogen are two leading eco-friendly candidates for supplementing world…

The long-held idea that only vertebrates have sophisticated adaptive immune systems that can protect them for life against many pathogens after being infected by them just once has been revised in recent years. It turns out that many insects also have a form of immune memory that protects them against reinvasion by a pathogen they have previously encountered. This was just one of the striking discoveries discussed at the recent conference on Innate Immunity and the Environment, organized by the European Science Foundation (ESF). The conference was set up to discuss innate immunity involving…

Finally, a win for human embryonic stem cells (hESCs). Mice whose skulls were made whole again by bone tissue grown from hESCs shows that healing critical-size defects (defects that would not otherwise heal on their own) in intramembraneous bone, the flat bone type that forms the skull, is a vivid demonstration of new techniques to use hESCs for tissue regeneration. Using mesenchymal precursor cells isolated from hESCs, the Hopkins team steered them into bone regeneration by using “scaffolds,” tiny, three-dimensional platforms made from biomaterials. Physical context, it turns out, is a…

An effective and sensitive new method for detecting and characterizing prions, the infectious compounds behind diseases like mad cow disease, is now being launched by researchers at Linköping University in Sweden and other institutions. Mad cow disease (BSE), which has caused the death of more than 200,000 cattle and 165 people in the U.K., has now abated but other prion disorders are on the rise and there is concern that new strains will infect humans. Prions are not readily transmittable from species to species, but once they have broken through the species barrier they can rapidly adapt…

Acclaimed stem cell researcher Shinya Yamanaka, MD, PhD, has reported that he and his Kyoto University colleagues have successfully reprogrammed human adult cells to function like pluripotent embryonic stem (ES) cells. Because it circumvents much of the controversy and restrictions regarding generation of ES cells from human embryos, this breakthrough, reported in the journal Cell, should accelerate the pace of stem cell research. Last year, Yamanaka, who is also a senior investigator at the Gladstone Institute of Cardiovascular Disease (GICD), reported that he and his Kyoto colleagues had…

There's always been speculation that human embryonic stem cell research was not worth the controversy due to uncertainty about their value in research and objections from womens' rights groups on one side and right-to-life groups on the other. Pluripotent cell lines from a non-embryonic source would seem to satisfy everyone By introducing four genes into human fibroblasts,researchers can transform adult human skin cells into cells that resemble embryonic stem cells, researchers report in Cell. The converted cells have many of the physical, growth and genetic features typically found in…

MIT researchers have identified a family of proteins key to the formation of the communication networks critical for normal brain function. Their research could lead to new treatments for brain injury and disease. The team, led by MIT biology professor Frank Gertler, found that a certain family of proteins is necessary to direct the formation of axons and dendrites, the cellular extensions that facilitate communication between neurons. The work focuses on cellular outgrowths called neurites, which are the precursors to axons and dendrites. Understanding how neurites form could eventually lead…

It’s well known that the body’s energy levels cycle on a 24-hour, or circadian, schedule, and that this metabolic process is fueled by oxygen. Now, researchers at the University of Pennsylvania School of Medicine have found that a protein called Rev-erb coordinates the daily cycles of oxygen-carrying heme molecules to maintain the body’s correct metabolism. Many studies, including this one, point to a link between the human internal clock and such metabolic disorders as obesity and diabetes. Proteins such as Rev-erb are the gears of the clock and understanding their role is important for…

The cells which thicken the womb wall during a woman's menstrual cycle contain a newly discovered type of stem cell, and could be used in the treatment of damaged and/or old tissue, according to research published in the Journal of Translational Medicine. Dr Xiaolong Meng of the Bio-Communications Research Institute in Wichita, Kansas, led the research team consisting of scientists from the University of Alberta, University of Western Ontario and Medistem Laboratories (mdsm.ob). The team identified a new type of stem cell that can be reproducibly isolated from menstrual blood collected from…