Biotechnology

ScienceDaily (Oct. 22, 2012) — Our immune system must be tremendously complex to respond to the unending assault of viruses, bacteria and cancerous cells. One of the mechanisms used by the immune system to cope with the huge variety of possible threats is to randomly combine DNA segments for the production of receptors on lymphocytes -- a type of white blood cell. The number of possible receptors that can be produced in this way is about 1000 times the number of stars in our galaxy -- one followed by 15 zeroes. And yet, the actual array of receptors produced does not conform to this picture of random chance: Some receptors are produced at a higher rate than others. New research at the Weizmann Institute can help explain how the immune system maintains its complexity while giving preference to certain receptors. The research team headed by Dr. Nir Friedman, including postdoctoral fellows Drs. Wilfred Ndifon and Hilah Gal, together with Prof. Ruth Arnon a...

ScienceDaily (Oct. 22, 2012) — A University of Colorado Boulder-led team has discovered two prime targets of the Hepatitis B virus in liver cells, findings that could lead to treatment of liver disease in some of the 400 million people worldwide currently infected with the virus. CU-Boulder Professor Ding Xue, who led the studies, said scientists have been looking for cellular targets of the Hepatitis B virus, or HBV, for more than three decades. Infections from HBV promote hepatitis (inflammation of the liver), cirrhosis (scarring of the liver) and liver cancer and can be transmitted through blood and bodily fluids, unprotected sex, unsterile needles and from infected mother to offspring during birth. Xue said scientists have known for some time that HBV encodes a pathogenic, tumor-promoting protein known as HBx, but how it works has remained largely unknown. In two new studies, Xue and his colleagues showed that the "host targets" of HBx in ...

ScienceDaily (Oct. 22, 2012) — The glowing green molecule known as green fluorescent protein (GFP) has revolutionized molecular biology. When GFP is attached to a particular protein inside a cell, scientists can easily identify and locate it using fluorescence microscopy. However, GFP can't be used with electron microscopy, which offers much higher resolution than fluorescence microscopy. Chemists from MIT have now designed a GFP equivalent for electron microscopy -- a tag that allows scientists to label and visualize proteins with unprecedented clarity. "With things that may appear only a few pixels across by fluorescence microscopy -- for example, a mitochondrion -- you can't make out any of the internal features. But with electron microscopy it's very easy to discern the intricate internal structures," says Jeff Martell, a graduate student in chemistry at MIT and lead author of a paper describing the new tag in the Oct. 21 onlin...

ScienceDaily (Oct. 17, 2012) — Researchers from North Carolina State University and University of North Carolina at Chapel Hill have developed a new technique that uses sound waves to rapidly separate selected collections of cells for use in biomedical research. "We think this is important because it will make it faster and easier for researchers to sort out the live cells they need for research ranging from disease study to drug development," says Dr. Xiaoning Jiang, an associate professor of mechanical and aerospace engineering and adjunct professor of biomedical engineering at NC State and co-author of a paper on the work. Biomedical research often focuses on how specific cell types respond to various chemicals or environmental factors. These cells are often grown in a liquid medium and on top of a collection of "micropallets," which are essentially small plastic platforms that sit on the substrate at the bottom of the container. ...

ScienceDaily (Oct. 21, 2012) — Biochemists at The Scripps Research Institute (TSRI) have discovered a genetic sequence that can alter its host gene's activity in response to cellular energy levels. The scientists have found this particular energy-sensing switch in bacterial genes, which could make it a target for a powerful new class of antibiotics. If similar energy-sensing switches are also identified for human genes, they may be useful for treating metabolism-related disorders such as type 2 diabetes and heart disease. "This discovery adds a new dimension to our understanding of how cells sense and manage their energy levels, which is one of the most important processes in biology," said the study's senior author, Martha J. Fedor, a professor the departments of Chemical Physiology and Molecular Biology and a member of the Skaggs Institute for Chemical Biology at TSRI. The findings are described online ahead of print on October 21, 2...

ScienceDaily (Oct. 9, 2012) — Scientists from the Florida campus of The Scripps Research Institute (TSRI) have developed a new method of screening more than three million combinations of interactions between RNA and small molecules to identify the best targets on RNA as well as the most promising potential drug compounds. This novel technology may lead to more efficient drug development. The study was published in the October 9, 2012 issue of the journal Nature Communications . RNA has multiple biological functions, including encoding and translating proteins from genes and regulating the amount of protein expressed under various cellular conditions. Recent studies have identified RNA as a "molecular switch" that controls cellular events such as gene expression, making RNA an attractive target for small molecules that serve as chemical genetics probes, analytical tools or potential drugs. However, to date information on which small molecules...

ScienceDaily (Oct. 18, 2012) — A new approach for generating large numbers of circulatory system cells, known as vascular endothelial cells (VECs), from human amniotic-fluid-derived cells (ACs) is reported in a study published by Cell Press October 18th in the journal Cell . The strategy, which shows promise in mice, opens the door to establishing a vast inventory of VECs for promoting organ regeneration and treating diverse vascular disorders. "Currently, there is no treatment available for a broad range of patients with vascular diseases, including patients who have suffered heart attack, stroke, lung diseases, trauma, emphysema, or even diabetes and neurological disorders," says senior study author Shahin Rafii of Weill Cornell Medical College. "Replacing injured or dysfunctional endothelial cells with normal cultured endothelial cells could potentially provide for a novel therapy to treat these diseases that afflict millions of patients...