Genetics & Molecular Biology
Researchers have identified an important cause of why secondary corneal transplants are rejected at triple the rate of first-time corneal transplants.
The cornea - the most frequently transplanted solid tissue - has a first-time transplantation success rate of about 90 percent. But second corneal transplants undergo a rejection rate three times that of first transplants.
More than 40,000 transplants are performed annually to replace the cornea, the clear outer lens at the front of the eye, with tissue from a donor. Most corneal transplants are done to correct severe visual impairments caused by keratoconus, a condition in which the normally dome-shaped cornea progressively thins and becomes cone-shaped, according to the American Academy of Ophthalmology.
Most of today's anticancer drugs target the DNA or proteins in tumor cells, but a new discovery unveils a whole new set of potential targets: the RNA intermediaries between DNA and proteins.
This RNA, called messenger RNA, is a blueprint for making proteins. Messenger RNA is created in the nucleus and shuttled out into the cell cytoplasm to hook up with protein-making machinery, the ribosome. Most scientists have assumed that these mRNA molecules are, aside from their unique sequences, generic, with few distinguishing characteristics that could serve as an Achilles heel for targeted drugs.
It is estimated that 5% of women experience two clinical miscarriages and approximately 1% suffer three or more losses.
Researchers at the University of Warwick and University Hospitals Coventry and Warwickshire (UHCW) NHS Trust have found that body clock genes could affect women's ability to have children. The study pinpoints how body clock genes are temporarily switched off in the lining of the womb to allow an embryo to implant. Timing of this event is critical for pregnancy.
Shaved heads have come in and out of fashion over the past few decades, but some people don’t have the option of allowing their locks to grow.
Thankfully, for those who do suffer from hair loss, or alopecia, help may be at hand. Somewhat counter-intuitively an effective treatment for baldness may come from plucking a certain number of hairs – in a specific formation – from the scalp.
Skin is remarkably resistant to tearing and a team of researchers from the University of California, San Diego and the Lawrence Berkeley National Laboratory now have shown why.
Using powerful X-ray beams and electron microscopy, researchers made the first direct observations of the micro-scale mechanisms that allow skin to resist tearing. They identified four specific mechanisms in collagen, the main structural protein in skin tissue, that act together to diminish the effects of stress: rotation, straightening, stretching, and sliding. Researchers say they hope to replicate these mechanisms in synthetic materials to provide increased strength and in better resistance to tearing.
Bacteria have an immune system to fight off invasive viruses called phages, and like any immune system, from single-celled to human, the first challenge of the bacterial immune system is to detect the difference between “foreign” and “self.”
Since all living things are made of DNA and proteins, how do viruses and bacteria recognize their own?
“In most environments, phages are around ten times more abundant than bacteria. And, like all viruses, phages use the host cell’s replication machinery to make copies of themselves,” says Prof. Rotem Sorek of the Weizmann Institute’s Department of Molecular Genetics. “And they are constantly evolving new ways to do this. So bacteria need a very active immune system to survive.”
When a heart attack strikes, the effects are lingering: heart muscle cells die and scar tissue forms, which makes future heart failure more likely.
Gene variations that could mean yield increases, drought tolerance and aflatoxin resistance will boost productivity in the years to come.
A study included the growing years of 2011, a drought year, and 2012, on dryland and irrigated corn in College Station and in Mississippi, all with similar results, said Dr. Seth Murray, an AgriLife Research corn breeder in the soil and crop science department of Texas A&M University at College Station.
A broccoli variety modified to have two to three times more of the naturally occurring compound glucoraphanin, which is linked to antioxidants and other health benefits, also reduces blood LDL-cholesterol levels by around 6%, according to results of human trials.
Glucoraphanin is thought to work by helping maintain cellular metabolism. Mitochondria, the energy factories of the cell, convert sugars and fats into energy, but if they aren't working efficiently, one response is to channel excess into cholesterol.
A new study has found that nearly all pancreatic cancers enslave and deform mitochondria, the powerhouses of cells, and force them to divide unnaturally, to lose their normal shape and collapse around the cell's nucleus.
This creates an environment even more conducive to tumor growth.