While the origin of life remains mysterious, scientists are finding more and more evidence that material created in space and delivered to Earth by comet and meteor impacts could have given a boost to the start of life. Some meteorites supply molecules that can be used as building blocks to make certain kinds of larger molecules that are critical for life.

February 03, 2014, OAKLAND, Calif. —Tests that require patients to collect a single stool sample at home and then send it to a lab for analysis will detect about 79 percent of colorectal cancers, according to a new evidence review published in the Annals of Internal Medicine. The review of 19 studies examining eight different fecal immunochemical tests, know as "FITs", also finds that the tests will correctly identify about 94 percent of patients who do not have cancers of the rectum or colon.

"We know the FIT is easy to use, and now we also know that it is a great tool for assessing which patients have cancer and which patients don't," said Beth Liles, MD, review co-author and clinical investigator at the Kaiser Permanente Center for Health Research in Portland, Ore.

Adoption of new guidelines recommending screening mammography every two years for women ages 50 to 74 would result in breast cancer screening that is equally effective, while saving the United States $4.3 billion a year in health care costs, according to a study led by UC San Francisco.

The study compares three possible mammography screening strategies with a model of current U.S. screening practices.

The article appears on February 4, 2014 in Annals of Internal Medicine.

PHILADELPHIA — Among patients with advanced melanoma, presence of higher levels of the protein vascular endothelial growth factor (VEGF) in blood was associated with poor response to treatment with the immunotherapy ipilimumab, according to a study published in Cancer Immunology Research, a journal of the American Association for Cancer Research.

The study suggests combining immunotherapy with VEGF inhibitors, also known as angiogenesis inhibitors, may be a potential option for these patients.

Australian researchers have shed more light on an underexplored aspect of the important brain-signaling system that controls appetite, body composition and energy use. Their findings suggest that a specific gene regulating our body clock may play a central role in determining how fat we become.

Evolution has preserved the 'neuropeptide Y (NPY) system', as it is known, in most species – indicating its importance – and much of our understanding comes from studying it in mice. There is one important difference, however, between the NPY system in mouse and man.

In man, the neurotransmitter NPY communicates with four well-known 'cell surface receptors' in the brain (Y1, Y2, Y4 and Y5), which in turn trigger the system's effects.

In adults, some brain regions retain a "childlike" ability to establish new connections, potentially contributing to our ability to learn new skills and form new memories as we age, according to new research from Washington University School of Medicine in St. Louis and the Allen Institute for Brain Science in Seattle.

The scientists arrived at the new findings by comparing gene activity levels in different regions of the brain. They identified adult brain regions where genes linked to the construction of new connections between cells have higher activity levels. The same genes are also highly active in young brains, so the researchers called this pattern of gene activity childlike.