Microbiology

A natural, biological pacemaker; that's what a heart is, right?  Sure, but our hearts can wear out and while artificial heart pacemakers have saved and extended the lives of thousands of people, but they have their shortcomings – such as a fixed pulse rate and a limited life. Could a permanent replacement biological solution be in our future?   Richard Robinson and colleagues at New York's Columbia and Stony Brook Universities certainly think so, and their work published in the latest issue of The Journal of Physiology outlines how we can bring it a step closer to reality. The…

Complex objects like automobiles and birthday cakes are created using a 'top down' process; the structure is imposed from the outside.    When things grow using order imposed from within, like biological objects, it is called a bottom-up approach.    The construction of complex man-made objects--a car, for example, or even a pizza--almost invariably entails what are known as "top-down" processes, in which the structure and order of the thing being built is imposed from the outside (say, by an automobile assembly line, or the hands of the pizza maker). "Top-down approaches…

New genome sequence information from the humble baker's yeast has revealed surprising variation in a set of genes that can be thought of as nature's oldest clock. In a paper published in Genome Research scientists show how ribosomal RNA genes that are essential to all Earth's organisms provide insight into how genomes maintain their integrity on their evolutionary journey. Ribosomal RNA sequence changes have been ticking away like clockwork for over 3 billion years, maybe even pre-dating the origin of the DNA world itself. However, even the slightest changes in sequence of these genes can be…

Johns Hopkins researchers have discovered a new energy-making biochemical twist in determining the lifespan of yeast cells, one so valuable to longevity that it is likely to also functions in humans.  Their findings, published in the March 20 issue of Cell, reveal that making glucose is highly influenced by a large enzyme complex already known to fix damaged DNA, and which apparently affects yeast life span through a common chemical process—acetylation.  In a series of experiments, the Hopkins team showed that when continuously acetylated, the so-called NuA4 enzyme complex causes…

Results of the first human clinical studies confirm that a new yogurt fights the bacteria that cause gastritis and stomach ulcers with what researchers describe as almost vaccine-like effects, according to scientists at the 237th National Meeting of the American Chemical Society. Researchers have long known that yogurt, a fermented milk product containing live bacteria, is a healthy source of calcium, protein, and other nutrients. Some brands of yogurt are now made with probiotics — certain types of bacteria — intended to improve health. The new yogurt represents a unique approach to…

A preliminary study on the application of thermo-microbiology and its relation to time of death has been released by Professor Isabel Corcobado and colleagues at the University of Granada.  The ultimate goal of this project is to use a microbiological indicator along with existing forensic techniques in order to determine time of death in forensics cases more accurately. Corcobado's research established the initial methodological basis to create a protocol using thermography and microbiology in forensics.  Such a protocol would provide a new criminalistic approach in estimating time…

 Cells keep up with the Joneses.  The peer pressure of signals from complementary cells tells a stem cell how and when to differentiate and grow.  Dr. Carolyn Bertozzi and her team at Lawrence Berkeley laboratory are using molecular self-organization tendencies to give cells the orderly neighborhoods they desire.   However, this microscopic community has an unusual dress code-- the cells display DNA on the outside of their membranes, which allows them to keep each other in line. Unlike the cells' nuclear DNA, the exterior DNA doesn't serve a genetic purpose.  It is a…

Sometimes known as "nature's origami", the way that proteins fold is vital to ensuring they function correctly. But researchers at the University of Leeds have discovered this is a 'hit and miss' process, with proteins potentially folding wrongly many times before they form the correct structure for their intended purpose.  The body's proteins carry out numerous functions and play a crucial role in the growth, repair and workings of cells. Sheena Radford, Professor of Structural Molecular Biology at the University of Leeds, says: "There's a fine balance between a protein folding into the…

The agglutination and accumulation of proteins in nerve cells are major hallmarks of age-related neurodegenerative illnesses such as Alzheimer's disease. Cellular survival thus depends on a controlled removal of excessive protein. Scientists at Johannes Gutenberg University Mainz have now discovered exactly how specific control proteins regulate protein breakdown during the ageing process. Every protein in our cells has a defined life span. At the end of this time and even sooner (e.g., in response to injury caused by external factors such as oxidative stress), proteins are eliminated by…

In times of starvation, cells tighten their belts: they start to digest their own proteins and cellular organs. The process - known as autophagy - takes place in special organelles called autophagosomes. It is a strategy that simple yeast cells have developed as a means of survival when times get tough, and in the course of evolution, it has become a kind of self-cleaning process. In mammalian cells, autophagosomes are also responsible for getting rid of misfolded proteins, damaged organelles or disease-causing bacteria.  If this process malfunctions, it can result in infectious diseases…