Population differences in cardiovascular reactivity to the cold pressor test

The interaction of race and climatic adaptation on patterns of cardiovascular reactivity among young adult males was examined. Malay and Chinese subjects living in a tropical climate in the Orient and Caucasians living in a sub-tropical climate in North America were investigated. The cold pressor test with hand immersion in cold water was used as the stressor. Systolic and diastolic blood pressures, cardiac frequency, cardiac output, and stroke volume were measured. The results provided limited evidence for absence of differences in cardiac reactivity among racial groups and for greater vascular reactivity in the Caucasians. Cold immersion also elicited differential responses which could be partially attributed to differences in acclimatizations status. © 1995 Wiley-Liss, Inc.     

Sleep deprivation effects on growth factor expression in neonatal rats: a potential role for BDNF in the mediation of delta power

The sleeping brain differs from the waking brain in its electrophysiological and molecular properties, including the expression of growth factors and immediate early genes (IEG). Sleep architecture and homeostatic regulation of sleep in neonates is distinct from that of adults. Hence, the present study addressed the question whether the unique homeostatic response to sleep deprivation in neonates is reflected in mRNA expression of the IEG cFos, brain-derived nerve growth factor (BDNF), and basic fibroblast growth factor (FGF2) in the cortex. As sleep deprivation is stressful to developing rats, we also investigated whether the increased levels of corticosterone would affect the expression of growth factors in the hippocampus, known to be sensitive to glucocorticoid levels. At postnatal days 16, 20, and 24, rats were subjected to sleep deprivation, maternal separation without sleep deprivation, sleep deprivation with 2 h recovery sleep, or no intervention. mRNA expression was quantified in the cortex and hippocampus. cFos was increased after sleep deprivation and was similar to control level after 2 h recovery sleep irrespective of age or brain region. BDNF was increased by sleep deprivation in the cortex at P20 and P24 and only at P24 in the hippocampus. FGF2 increased during recovery sleep at all ages in both brain regions. We conclude that cortical BDNF expression reflects the onset of adult sleep-homeostatic response, whereas the profile of expression of both growth factors suggests a trophic effect of mild sleep deprivation.     

Depression and social stress in Pakistan

BACKGROUND: The high prevalence of depression in developing countries is not well understood. This study aimed to replicate the previous finding of a high prevalence of depression in Pakistan and assess in detail the associated social difficulties. METHOD: A two-phase survey of a general population sample in a Pakistani village was performed. The first-phase screen used the Personal Health Questionnaire (PHQ) and the self-rating questionnaire (SRQ). A one in two sample of high scorers and a one in three sample of the low scorers were interviewed using the Psychiatric Assessment Schedule (PAS) and Life Events and Difficulties Schedule (LEDS). RESULTS: A total of 259 people were screened (96% response rate). The second stage yielded 55 cases, of whom 54 had depressive disorder, and 48 non-cases. The adjusted prevalence of depressive disorders was 44-4% (95% CI 35.3 to 53.6): 25.5% in males and 57.5% in females. Nearly all cases had lasted longer than 1 year. Comparison of the cases and non-cases indicated that cases were less well educated, had more children and experienced more marked, independent chronic difficulties. Multivariate analysis indicated that severe financial and housing difficulties, large number of children and low educational level were particularly closely associated with depression. CONCLUSION: This study confirms the high prevalence of depressive disorders in Pakistan and suggests that this may be higher than other developing countries because of the high proportion of the population who experience social adversity.     

Effect of subjective perspective taking during simulation of action: a PET investigation of agency

Perspective taking is an essential component in the mechanisms that account for intersubjectivity and agency. Mental simulation of action can be used as a natural protocol to explore the cognitive and neural processing involved in agency. Here we took PET measurements while subjects simulated actions with either a first-person or a third-person perspective. Both conditions were associated with common activation in the SMA, the precentral gyrus, the precuneus and the MT/V5 complex. When compared to the first-person perspective, the third-person perspective recruited right inferior parietal, precuneus, posterior cingulate and frontopolar cortex. The opposite contrast revealed activation in left inferior parietal and somatosensory cortex. We suggest that the right inferior parietal, precuneus and somatosensory cortex are specifically involved in distinguishing self-produced actions from those generated by others.     

A novel frame shift mutation in the HMG box of the SRY gene in a patient with complete 46,XY pure gonadal dysgenesis.

Pure gonadal dysgenesis or Swyer syndrome is a sex-reversal disorder resulting from embryonic testicular regression sequences especially during the first few weeks of fetal life and is induced by mutations in the SRY gene. In the present report, we describe a nonmosaic XY sex-reversed female with pure gonadal dysgenesis. Molecular analysis using sequential PCR to detect Y chromosomal microdeletions showed the presence of SRY, ZFY and AZFa, b and c regions. Automated sequencing of the SRY region revealed a new mutation (deletion of A (adenine) in codon 82 at position +244), leading to a frame shift mutation within the helix I of the HMG-box domain. This mutation generates a truncated protein and is very likely to produce an impairment of SRY DNA binding activity. The present findings further support the functional importance of the putative DNA binding activity of the SRY HMG-box domain.     

The Essential Oil of Perilla ocimoides: A Rich Source of Rosefuran

The essential oil of a strain of PERILLA OCIMOIDES from Bangladesh, cultivated at Lucknow, after GC-MS investigations afforded rosefuran ( 1) as the major constituent (58%) along with 17 others including beta-caryophyllene, perilla ketone ( 2), perillene, alpha-cedrene, germacrene-D, and isobis-abolene.