Body

A foundational study published in top biomedical journal PNAS (Proceedings of the National Academy of Sciences) this week by researchers at the University of Toronto's Institute of Biomaterials & Biomedical Engineering (IBBME) and the McEwen Centre for Regenerative Medicine have identified the optimal structure and cell ratio associated with heart function – and the discovery has already led the team to another research first: the engineering of the first-ever living, three-dimensional human arrhythmic tissue.

COLLEGE STATION, Nov. 20, 2013 – Results from a DNA study of a young boy's skeletal remains believed to be 24,000 years old could turn the archaeological world upside down – it's been proven that nearly 30 percent of modern Native American's ancestry came from this youngster's gene pool, suggesting First Americans came directly from Siberia, according to a research team that includes a Texas A&M University professor.

PROVIDENCE, R.I. [Brown University] — Biologists at Brown University have found a way to measure the effects of aging by watching the ebb and flow of chromatin, a structure along strands of DNA that either silences or permits gene expression. In several newly published experiments they show that gene silencing via chromatin in fruit flies declines with age.

Results of a Johns Hopkins-led study have identified a possible link between a history of sudden drops in blood pressure and the most common form of irregular heartbeat.

The study suggests that a bout of orthostatic hypotension — a steep blood pressure drop that occurs when a person stands up after a period of lying down — appears to be associated with an overall 40 percent increase in the risk of developing atrial fibrillation over the following two decades.

Our epigenome is a set of chemical switches that turn parts of our genome off and on at strategic times and locations. These switches help alter the way our cells act and are impacted by environmental factors including diet, exercise and stress. Research at the Buck Institute reveals that aging also effects the epigenome in human skeletal muscle. The study, appearing on line in Aging Cell, provides a method to study sarcopenia, the degenerative loss of muscle mass that begins in middle age.

COLUMBIA, Mo. – Hormone replacement therapies, or medications containing female hormones that substitute those no longer produced by the body, are often prescribed to reduce the effects of hot flashes and other menopausal symptoms in women. Research and clinical trials on hormone replacement therapies have indicated a higher incidence of tumors, especially breast cancer, in post-menopausal women who take synthetic hormones; therefore, doctors have become more reluctant to prescribe the treatment.

Chevy Chase, MD—Older men whose testosterone levels were neither low nor high tended to live longer, according to new research accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism.

Testosterone is a key male sex hormone involved in maintaining sex drive, sperm production and bone health. Physicians have long known that low testosterone levels can signal health problems, but the new study found men may not fare better when levels of the hormone rise too high.

Chevy Chase, MD—Obese people who are currently metabolically healthy face a higher risk of developing diabetes and cardiovascular disease, according to new research accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism.

The genome sequence of a 24,000-year-old Siberian individual has provided a key piece of the puzzle in the quest for Native American origins. The ancient Siberian demonstrates genomic signatures that are basal to present-day western Eurasians and close to modern Native Americans. This surprising finding has great consequences for our understanding of how and from where ancestral Native Americans descended, and also of the genetic landscape of Eurasia 24,000 years ago.

ANN ARBOR—When Kaitlyn Patterson's fatigue progressed to hyperventilating even during slow runs, and then forced her to quit high school distance running for the season, she knew something was very wrong.

Northbrook, Illinois, November 20, 2013. Experts from the world's leading lung organizations have come together for the first time to call for a worldwide effort to improve health-care policies and systems and care delivery to make a positive difference for the lung health of the world.

Produced by the Forum of International Respiratory Societies (FIRS), the report has been launched today, on World COPD Day, providing an overview of lung health across the globe.

In Europe in 2012, there were an estimated 39,900 new cases of laryngeal cancer and 99,600 new cases of oral cavity and pharyngeal cancers (Feraly et al.). The estimated number of deaths from laryngeal and oral cavity and pharyngeal cancers were 19,800 and 43,700, respectively. These types of cancers can negatively affect the health related quality of life (HRQOL), because they induce symptoms that may interfere with daily life.

CHICAGO (November 20, 2013) – Two studies published in the December issue of Infection Control and Hospital Epidemiology show antibiotic resistance patterns for children have held stable over a seven-year period and surgical patients in U.S. children's hospitals account for 43 percent of all antibiotic use in children's hospitals, presenting an opportunity for targeted intervention.

Diet alone can be a significant source of arsenic exposure regardless of arsenic concentrations in drinking and cooking water, a Dartmouth College-led study finds.

The study also confirms that toenail clippings are a good biomarker of long-term exposure to arsenic from consuming alcohol, Brussels sprouts and dark meat fish. Exposure to arsenic has been linked to a variety of health problems, including cancer, vascular diseases and low birth weight.

Bone grafts, which are used to treat head injuries and birth defects, still pose major medical challenges, but scientists are reporting progress toward a new hormone therapy that could improve the outcomes of these surgeries. Their study, which was conducted on mice, appears in the ACS journal Molecular Pharmaceutics.