Editor's choice: Hearing, lab mice, inherited diet and antibiotics
A round-up from the scientific and technical journals.
A way to restore hearing?
Researchers from the University of New South Wales have discovered a unique way to restore hearing. They took advantage of the fact that cochlear implants, which convert sound into electrical pulses, can also deliver DNA into the cells of the inner ear. Pulses of electricity momentarily create pores in cell membranes and DNA can slip through. The DNA carried instructions for the cells to make a protein called brain derived neurotrophic factor that triggers the regeneration of auditory nerves. Cells taking up the DNA successfully produced the protein and guinea pigs with the DNA-impregnated cochlear implant showed better hearing than those with the regular model. But the effects faded after six weeks, presumably because the DNA disintegrated and researchers are working on finding a way to stabilise it. A full report here.
Male researchers add to stress of lab mice
The sex of a researcher can change the outcome of experiments on lab mice, a new study shows. Lab scientists have often observed that mice react differently to men than to women. Canadian researchers have now measured the effect, showing that men in the lab, or even the presence of a T-shirt previously worn by a man, elevate the animals' stress levels. The stressed mice showed altered behaviour, including a dulled pain response. Researchers may now have to factor the gender of the handler into their results. A report of the findings can be found here.
You are what your mother ate
You’re not just what you eat. Increasing evidence suggests you are also what your mother ate, especially around the time she conceived you. Research on animals has shown that a mother's diet can reprogram her offspring's genes by changing the levels of chemicals called methyl groups - markings that switch genes on or off. New research has tested the theory on people, by examining Gambian women whose diet fluctuated with the season. Women were hungrier in the wet season than in the dry harvest season. Babies conceived in the different seasons showed different markings of methyl groups on some of their genes. But contrary to the researchers’ initial expectations, genes of babies conceived during the hungry season had more methyl groups, not less. Why? The researchers are now trying to find out. A report of the study is here.
A glimpse of life without antibiotics
In its first global assessment of antibiotic-resistant bacteria, the World Health Organization reports that resistance has spread to every corner of the world and has “the potential to affect anyone, of any age, in any country”. In some cases the situation is already dire. More than a million people are infected with gonorrhoea every day but some strains are now resistant to every drug in our arsenal. People, policymakers and the health industry must urgently work together, the WHO urges, to slow the dwindling effectiveness of existing drugs and promote the development of new ones if we are to avoid a rapid slide into a post-antibiotic era.
- http:// http://stm.sciencemag.org/content/6/233/233ra54