Reproductive and somatic aging use different molecular mechanisms that show little overlap between the types of genes required to keep oocytes healthy and the genes that generally extend life span, according to Coleen Murphy, Ph.D., of Princeton University, who described her new findings on oocyte aging at the American Society for Cell Biology Annual Meeting in Denver. The different genetic pathways help explain why a woman's fertility begins to decline after she is 35 years old, while her other cells do not show significant signs of aging until decades later, Murphy explained. To compare the molecular mechanisms that are switched on or off with the aging of oocytes and somatic cells, Murphy's lab turned to the model organism, Caenorhabditis elegans ( C. elegans ), the worm-like nematode that set off the whole field of longevity research with the discovery in the 1990s that gene mutations affecting insulin regulation doubled the worm's life span.
Males who place a laptop on their laps with the WI-FI on might have a greater risk of reduced sperm motility and more sperm DNA fragmentation, which could, in theory, undermine their chances of becoming fathers, researchers from Nascentis Medicina Reproductiva, Argentina, and the Eastern Virginia Medical School, USA, reported in the journal Fertility and Sterility this week. Sperm motility refers to the percentage of sperm in a semen sample that are moving - normally, a high percentage of all sperm should be moving (thrashing their tails and swimming). This study was done in an artificial setting. The male participants were not tested with the laptops on their laps - semen samples were taken, placed under laptops for four hours, and then analyzed. Previous studies had already shown that placing a laptop on a man's lap could potentially affect his fertility, especially if this occurs frequently and for long periods.
Teen births in the US hit a record low in 2010, and for the first time in a decade, C-sections appear to be falling, according to the latest figures from the Centers for Disease Control and Prevention (CDC). These revelations are in a report released last week titled "Births: Preliminary Data for 2010" from the CDC's National Center for Health Statistics. The figures come from an analysis of nearly 100% birth records collected in all 50 states, the District of Columbia and US territories. The report shows, among other things, that the proportion of 15 to 19-year-olds in the US giving birth has fallen every year in the last three years and for 17 out of the last 19 years, falling to 34.3 births for every 1, 000 teenagers in 2010. This is a 9% fall from the 2009 figure and the lowest rate recorded in nearly 70 years of collecting such data.
There is a significant link between use of oral contraceptives or birth control pills and the incidence of prostate cancer, said researchers who set out to investigate the suggestion that byproducts of these drugs get into the environment, for instance the water supply, and lead to an increase in low level estrogen exposure in affected populations. David Margel, and Neil E Fleshner from the Princess Margaret Hospital at the University of Toronto in Canada, write about their findings in the 14 November online issue of BMJ Open. They conclude that their study shows a significant association between oral contraceptives and prostate cancer and that: "It is hypothesised that the [oral contraceptive] effect may be mediated through environmental oestrogen levels; this novel concept is worth further investigation.
New research in Developmental Cell suggests that increasing expression of certain developmental genes at precise times in the uterus might improve pregnancy rates from in vitro fertilization-embryo transfers (IVF-ET), which remain low at around 30 percent. Conducted by researchers at Cincinnati Children's Hospital Medical Center, the study was published online by the journal on Nov. 17. Researchers point to the genes Msx1 and Msx2 - which play integral roles in organ formation during fetal development - as essential to ensuring the uterus is in a receptive phase needed for successful embryo implantation. Compromised uterine receptivity is a major cause of pregnancy failure in IVF programs, according to Sudhansu K. Dey, PhD, director of the Division of Reproductive Sciences in the Perinatal Institute at Cincinnati Children's.