Season of birth and fluctuating asymmetry.

Fluctuating asymmetry (FA) refers to random, small deviations from perfect bilateral symmetry in morphological traits. These minor deviations from the ideal phenotype reflect environmental and genetic perturbations experienced during ontogeny. FA has been associated with negative health outcomes and many developmental disorders in humans. The prevalence of developmental disorders and adult health vary according to the month of birth, suggesting that seasonal stressors may leave enduring signs in the adult body, marked by high FA. The current study examined the relationship between FA and birth season. Data were collected for 205 males and females (average age = 20.39 years) on FA of 10 bilateral traits (second, third, fourth, and fifth digit length, palm height, wrist diameter, elbow width, ear height, foot breadth, and ankle circumference). Additional relationships were also investigated among FA, testosterone (T), and birth order. Results indicate that ear FA was lower for fall births compared to winter births in males. In females, palm FA was lower for fall births compared to those of the spring. FA of the digits was positively associated with T in males. Average FA, excluding the digits, decreased as the number of maternal siblings increased for both sexes. T concentrations in males were positively associated with the number of younger brothers. Our results generally confirm previous research on seasonal variation in adult longevity and neurological and psychiatric disorders, suggesting that winter and spring births are at risk for asymmetric developmental trajectory.     

Electroencephalographic sleep measures in prepubertal depression.

Two nights of electroencephalographic (EEG) sleep recording were performed in a group of prepubertal subjects with major depressive disorder (MDD) (n = 36, mean age = 10.4, SD = 1.5) and age-matched normal control children (n = 18, mean age = 10.1, SD = 1.6). All subjects were medically healthy and free of medications at the time of the study. There were no significant group differences for any major sleep variable after the initial adaptation night in this study. One subgroup of MDD subjects (n = 8) showed reduced REM latency on both recording nights, decreased stage 4 sleep, and increased REM time; this subgroup had significantly higher severity scores for depression but did not otherwise appear to be clinically distinct from the rest of the MDD subjects. Overall, the results indicate that the EEG sleep changes associated with depression in adults occurred less frequently in prepubertal MDD subjects.     

On the role of Ca2+ in the toxicity of alkylating and oxidizing quinone imines in isolated hepatocytes

The cytotoxicity of acetaminophen (paracetamol) has been shown to be associated with a disruption of intracellular Ca2+ homeostasis caused by the interaction of its metabolite N-acetyl-p-benzoquinone imine (NAPQI) with hepatocyte thiols [Moore, M., et al. (1985) J. Biol. Chem. 260, 13035-13040]. Inasmuch as NAPQI can both covalently bind to thiols and oxidize thiols, we investigated the effects of two dimethylated analogues of NAPQI, one of which (2,6-dimethyl-NAPQI) primarily binds to thiols and the other of which (3,5-dimethyl-NAPQI) primarily oxidizes thiols. Of the three compounds, 2,6-dimethyl-NAPQI decreased protein thiols to the greatest extent and also inhibited hepatocyte plasma membrane Ca(2+)-ATPase to the greatest extent. The 3,5-dimethylated analogue decreased protein thiols to the least extent and inhibited the plasma membrane Ca(2+)-ATPase to a lesser extent. The cytotoxicity of all three compounds was preceded by a sustained elevation in cytosolic Ca2+ as compared to the transient rise caused by the alpha-agonist phenylephrine. Again, the 2,6-dimethyl analogue was the most potent of the three compounds. The thiol reagent dithiothreitol (DTT), which reversed the inhibition of the Ca(2+)-ATPase and the rise in cytosolic Ca2+, also protected against cytotoxicity. Agents that are known to inhibit either Ca(2+)-dependent proteases or phospholipases significantly delayed the onset of cytotoxicity caused by NAPQI and its analogues. Our results suggest that both arylation and oxidation of protein thiols may result in the elevation of cytosolic Ca2+ and in cytotoxicity and that arylation of critical thiol groups appears to be the more lethal reaction.     

Differences in preconceptional and prenatal behaviors in women with intended and unintended pregnancies.

OBJECTIVES: This study examined whether pregnancy intention was associated with cigarette smoking, alcohol drinking, use of vitamins, and consumption of caffeinated drinks prior to pregnancy and in early pregnancy. METHODS: Data from a telephone survey of 7174 pregnant women were analyzed. RESULTS: In comparison with women whose pregnancies were intended, women with unintended pregnancies were more likely to report cigarette smoking and less likely to report daily vitamin use. Women with unintended pregnancies were also less likely to decrease consumption of caffeinated beverages or increase daily vitamin use. CONCLUSIONS: Pregnancy intention was associated with health behaviors, prior to pregnancy and in early pregnancy, that may influence pregnancy course and birth outcomes.     

Prevalence of osteoporosis in women referred for bone density testing: utility of multiple skeletal sites.

The objective of this study was to determine retrospectively the prevalence of osteoporosis in a referral population and to compare the effectiveness of measuring multiple skeletal sites for identifying osteoporosis. Although osteoporosis is considered to be a major public health problem in the United States, and there are reliable methods for diagnosis based on bone densitometry, fewer than 25% of cases are currently identified. There is no consensus about which skeletal site(s) should be measured for optimal results. In this study, bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) at the radius (proximal site), lumbar spine, femoral neck, and total proximal femur regions in 537 consecutive white females age 50 and older referred by community physicians for bone densitometry. The prevalence of osteopenia and osteoporosis (based on the World Health Organization definitions) was determined, as well as the incidence of misclassification of patients based on different skeletal sites. Overall, 53.3% had osteoporosis, an additional 37.7% had osteopenia, and only 8.7% had normal BMD at all measurement sites. The prevalence was similar at all measurement sites and the incidence of misclassification was low. Given the magnitude of undetected osteoporosis and the efficacy of bone densitometry at any skeletal site, these data have important implications for the optimal deployment of bone density measurement facilities.