Body

Some cases of male infertility are due to mutations in the maternal X chromosome that prevent development of viable sperm, according to a study led by researchers at the University of Pittsburgh School of Medicine and the Magee-Womens Research Institute (MWRI). The study was published online today in the New England Journal of Medicine.

An international team, including archaeologists from the University of Southampton, has found evidence suggesting leprosy may have spread to Britain from Scandinavia.

The team, led by the University of Leiden, and including researchers from Historic England and the universities of Southampton, Birmingham, Surrey, and Swansea, examined a 1500 year old male skeleton, excavated at Great Chesterford in Essex, England during the 1950s.

Secondhand exposure to cannabis smoke under "extreme conditions," such as an unventilated room or enclosed vehicle, can cause nonsmokers to feel the effects of the drug, have minor problems with memory and coordination, and in some cases test positive for the drug in a urinalysis. Those are the findings of a Johns Hopkins University School of Medicine study, reported online this month in the journal Drug and Alcohol Dependence.

Whether you're brainy, brawny or both, you may someday benefit from a drug found to rejuvenate aging brain and muscle tissue.

Researchers at the University of California, Berkeley, have discovered that a small-molecule drug simultaneously perks up old stem cells in the brains and muscles of mice, a finding that could lead to drug interventions for humans that would make aging tissues throughout the body act young again.

Scientists at the University of Southampton have shown that although some studies find diet can enhance the effects of exercise to prevent muscle loss in later life, current evidence about what works is inconsistent.

Between the ages of 40 and 80, an estimated 30 to 50 per cent of muscle mass is lost, resulting in lower strength and less ability to carry out everyday tasks. This process - known as sarcopenia - is common and clearly linked to frailty and poorer health in older people. The associated health care costs are substantial.

Driving down the highway, you encounter ever-changing signs -- speed limits, exits, food and gas options. Seeing these roadside markers may cause you to slow down, change lanes or start thinking about lunch. In a similar way, cellular structures called microtubules are tagged with a variety of chemical markers that can influence cell functions.

Transposable elements are DNA sequences that are capable of changing their genome position by cut and paste or copy and paste through the enzyme transposase. This ability can be harmful for hosts if transposable elements destroy functioning genes, but it can also bring advantages. From an evolutionary point of view, transposable elements diversify the genome and open up chances for adaptation.

DNA that uses its host

A new study shows that the microbial communities we carry in and on our bodies--known as the human microbiome--have the potential to uniquely identify individuals, much like a fingerprint. Harvard T.H. Chan School of Public Health researchers and colleagues demonstrated that personal microbiomes contain enough distinguishing features to identify an individual over time from among a research study population of hundreds of people.

Men with naturally high levels of the female hormone oestrogen may have a greater risk of developing breast cancer, according to research by an international collaboration including Cancer Research UK published today in the Journal of Clinical Oncology.

This is the first time a link between oestrogen levels in the blood and male breast cancer has been identified, despite its connection to breast, womb and ovarian cancers in women.

The bacteria that sneak past the brain's defenses to cause deadly bacterial meningitis are clever adversaries. Brandon Kim would know. The biology graduate student at San Diego State University investigates the molecular tricks bacteria use to convince their host that they are harmless and cause disease.

One of developmental biology's most perplexing questions concerns what signals transform masses of undifferentiated cells into tremendously complex organisms, a process called ontogeny.

New research by University at Buffalo scientists, published last week in PLOS ONE, provides evidence that it all begins with a single "master" growth factor receptor that regulates the entire genome.

A team led by scientists at The Scripps Research Institute (TSRI) and Johns Hopkins University School of Medicine has uncovered a big clue to how bacteria may promote some colon cancers.

The study, reported in Cell Metabolism on May 7, 2015, used novel metabolomic technologies to reveal molecular evidence suggesting a vicious circle in which cancerous changes in colon cells promote the growth of bacterial conglomerations called biofilms, and biofilms in turn promote cancer development.

Scientists at the University of Copenhagen have identified one mechanism that explains how some stem cells choose to become a given cell type: the cells combine specific sets of proteins at precise positions along the DNA. When these particular groups of proteins are combined, the gates are opened so that certain groups of genes can now be used, giving the cells a new identity.

Scientists at Johns Hopkins say they've discovered a cause-and-effect link between chronic high blood sugar and disruption of mitochondria, the powerhouses that create the metabolic energy that runs living cells. The discovery, reported online in Proceedings of the National Academy of Sciences on April 27, sheds light on a long-hidden connection and, they say, could eventually lead to new ways of preventing and treating diabetes.

Using proteomics techniques to study injured optic nerves, researchers at Boston Children's Hospital have identified previously unrecognized proteins and pathways involved in nerve regeneration. Adding back one of these proteins--the oncogene c-myc--they achieved unprecedented optic nerve regeneration in mice when combined with two other known strategies. The findings were published online April 30 by the journal Neuron.