Genes & Cells

Fertility treatment risks
Fertility treatments may cause chromosomal problems in would-be mothers over age 35. A new study by researchers in Europe and Canada shows that chromosomes in older women may come prematurely unglued from one another when the ovaries are stimulated to produce eggs for in vitro fertilization. The unglued chromosomes may get divided up incorrectly during egg formation, leading to eggs with extra copies of chromosomes. An extra copy of a chromosome may result in fertility treatment failure, miscarriage, or — more rarely — Down syndrome or other conditions. The research was presented July 4 in Stockholm at the annual meeting of the European Society of Human Reproduction and Embryology. —Tina Hesman Saey

Vitamin A boosts diarrhea vaccines
A shot of vitamin A could make vaccines against diarrheal illnesses work better. Vaccines against diarrhea-causing bacteria are often ineffective because the vaccines rally immune cells that then float around the body instead of going to the gut where they’re needed. But researchers in Germany report July 1 in the Journal of Clinical Investigation that adding retinoic acid, or vitamin A, to the vaccine can make immune cells home in on the intestines. Mice injected with the vitamin-vaccine combo were able to fend off diarrhea caused by cholera toxin and had fewer Salmonella bacteria in their guts compared with immunized mice that didn’t get the vitamin boost. —Tina Hesman Saey

Source of brain cancer identified
Researchers have traced the source of the type of brain cancer that killed U.S. Senator Ted Kennedy. A type of stem cell called an oligodendrocyte precursor cell gives rise to malignant glioma, researchers led by Hui Zong of the University of Oregon in Eugene report online July 7 in Cell. Previously scientists thought the cancer originated one step back, in stem cells that produce the cells identified in the new study. Knowing which cells go haywire first may help scientists nip the deadly brain cancer in the bud.  —Tina Hesman Saey