The crying game
A new study suggests that most infants who wake up crying in the middle of the night are best left to self-soothe and fall back to sleep on their own. Researchers at Temple University in Philadelphia asked parents of more than 1,200 infants to report on their child's awakenings at six, 15, 24 and 36 months. They found two groups: sleepers (66 per cent) and transitional sleepers. By six months of age, the "sleepers" woke up just one night per week. But the "transitional sleepers" woke up seven nights per week at six months, dropping to one night per week by 24 months. Most wakers were boys. These transitional sleepers also tended to score higher on an assessment which identified traits such as irritability and distractibility. These babies were more likely to be breastfed and their mothers more likely to be depressed and have greater maternal sensitivity.
Gap year for women
The memory problems that many women experience as they approach and go through menopause not only exist, but appear to be most acute in the first year following a woman's final menstrual period. A study by University of Rochester Medical Centre in New York state published last week in the journal Menopause assessed 117 women with a series of tests to evaluate cognitive skills. The women also reported on menopause-related symptoms, and took a blood test for levels of oestradiol (an indicator of oestrogen levels) and follicle-stimulating hormone. Women in early post-menopause performed worse on verbal learning, verbal memory and fine motor skill than women in the late reproductive and late transition stages. However, lead author Miriam Weber, a neuropsychologist, says "these problems are normal and, in all likelihood, temporary".
Heart of the problem
Stanford University School of Medicine researchers have identified the molecular basis for a heart condition that is the most common cause of sudden cardiac death among young athletes. The scientists bioengineered heart muscle cells using special stem cells extracted from the skin cells of 10 members of a family with a genetic mutation that causes hypertrophic cardiomyopathy (abnormally thick heart muscle). They then compared these heart muscle cells from the family members who have the mutation to those without it. They found that the cells with the mutation began to change after about 30 to 40 days in culture - displaying abnormal rhythms and elevated calcium levels. This is the first time calcium's role in hypertrophic cardiomyopathy has been demonstrated conclusively in human cells. The researchers also used the bioengineered heart cells to quickly pinpoint the drugs most likely to be effective in human patients and to study their potential as preventive medications.