Neurobehavioural assessment of newborns.

Twenty-one full term appropriate for gestational age (FT-AGA), 18 full term small for gestational age (FT-SGA), 18 preterm appropriate for gestational age (PT-AGA) and 15 babies who suffered birth anoxia constituted study subjects. They were subjected to neurobehavioural assessment using Brazelton neurobehaviour assessment scale. FT-SGA babies performed significantly poorly on motor and interactive processes only. No differences were found in terms of overall state organisation. PT-AGA also performed poorly on interactive and motor processes but were placed better than SGA babies. Here also no definite pattern was observed in organisational dimension. No significant effect of asphyxia on behavioural pattern of FT-AGA babies was observed when compared to FT-AGA non-anoxic babies.

Sexually dimorphic cognitive style, female sex hormones, and cortical nitric oxide.

Recent studies using the water maze (WM) found marked sex differences in behavioral strategy employed in place learning tasks in adult rats. When a change in the platform position is introduced following learning the place of a platform (visible or hidden) in a different position, female rats escape to the newly positioned visible platform faster than males. Nitric oxide (NO) is implicated in place learning, and there are regional sex differences in its stable metabolites, NO(2)(-)+NO(3)(-), in rat brain. Furthermore, NO(2)(-)+NO(3)(-) levels are sensitive to ovariectomy in female rats. The effect of sex hormones on brain development and function is well documented. The present study was undertaken to study the effects of ovariectomy and hormonal manipulations on cognitive performance in a WM task designed to test differences in behavioral strategy in Sprague-Dawley rats (n=48) of both sexes. Some of the females rats were ovariectomised and received either hormone replacement (estrogen or progesterone alone or in combination) or the vehicle. Cortical and hippocampal NO(2)(-)+NO(3)(-) levels were determined after behavioral testing. There were no group differences in cognitive ability or non-cognitive factors such as motivation or swim speed. Males and intact females differed in their cognitive style, but hormonal manipulations in female rats did not affect this relative use of behavioral strategy. There was a correlation between performance on the trial where sex differences were most prominent and NO(2)(-)+NO(3)(-) levels in the cortex. Our results suggest that the activational effects of circulating gonadal hormones do not play a major role in sexually dimorphic cognitive styles.

Epidemiology of childhood hepatitis B in India: vaccination related issues.

It has been estimated that presently hepatitis B kills more people every day than AIDS kills in a year world-wide. Infection with hepatitis B produces a wide range of manifestations ranging from asymptomatic carriers to persistent infections leading to chronic liver diseases and hepatocellular carcinoma. Availability of effective and safe vaccine has made all this preventable. To formulate on appropriate vaccination strategy for India the epidemiology of hepatitis B needs to be defined. This report critically reviews the available data. The burden of long term sequelae of HBV infection is probably under-diagnosed and under-reported in India. Prevalence studies of HBV markers indicate that India falls under the area of intermediate endemicity. Limited data on age-specific prevalence of HBV markers suggests that the majority of the infection seems to take place below 15 years of age, and most of it under one year. Perinatal transmission appears to contribute significantly to the carrier pool. Childhood vaccination for HB among the general population is the obvious strategy of choice. But more information is required to decide on the timing of the first dose.

A modular method for evaluating the performance of picture archiving and communication systems.

Modeling can be used to predict the performance of picture archiving and communication system (PACS) configurations under various load conditions at an early design stage. This is important because choices made early in the design of a system can have a significant impact on the performance of the resulting implementation. Because PACS consist of many types of components, it is important to do such evaluations in a modular manner, so that alternative configurations and designs can be easily investigated. Stochastic activity networks (SANs) and reduced base model construction methods can aid in doing this. SANs are a model type particularly suited to the evaluation of systems in which several activities may be in progress concurrently, and each activity may affect the others through the results of its completion. Together with SANs, reduced base model construction methods provide a means to build highly modular models, in which models of particular components can be easily reused. In this article, we investigate the use of SANs and reduced base model construction techniques in evaluating PACS. Construction and solution of the models is done using UltraSAN, a graphic-oriented software tool for model specification, analysis, and simulation. The method is illustrated via the evaluation of a realistically sized PACS for a typical United States hospital of 300 to 400 beds, and the derivation of system response times and component utilizations.

Cerebral palsy--is it a seasonal disorder?

A relationship between the season of birth and the occurrence of neurological disorders has already been reported. An attempt has been made to see if a similar relationship exists in the case of cerebral palsy also. The month of birth of all the 212 children with cerebral palsy attending specialised centres in New Delhi was ascertained. The month of birth was compared with the month-wise normal distribution of live births in Delhi. The difference in monthly trend was found to be statistically highly significant. Does it suggest that cerebral palsy is a seasonal disorder?

Significance of circulatory immune complexes in thromboangiitis obliterans (Buerger's disease).

Circulatory immune complexes were estimated in the sera of 25 patients and 20 age and sex matched controls by precipitation with 8% polyethylene glycol (PEG). Characterization of the immune complexes, thus obtained, was performed by the double immuno-diffusion method. The mean protein content of the PEG precipitates was significantly higher in the patients of thromboangiitis obliterans than in the controls. The immunoglobulins in the immune complexes were predominantly of mixed type in contrast to mainly single class immunoglobulins in the controls. C3 complement distribution in immune complexes of patients and control sera was 64% and 45% respectively. The immune complexes in patients were found to be biologically active. The mechanism of formation of circulatory immune complexes and their role in the pathogenesis of arteritis in relation to smoking of tobacco has been postulated.