Biomedical subjects
Publications and source records attributed to H Shukla.
A non-calcium-dependent chloride channel of conductance 62 pS, found in isolated inside-out patches of cultured fetal rat hippocampal neurons, is described. The channel does not require the presence of any neurotransmitter to be active and probably plays a part in maintaining the normal resting membrane potential.
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To evaluate the relationship of serum cerebrospinal fluid (CSF) and brain total bilirubin levels in asphyxia, an experiment was designed with 5 to 6-week-old Sprague-Dawley rats. The rats were randomized into control and experimental groups. All rats received intravenously 30 mg/kg of bilirubin. Four hours later the experimental group was asphyxiated. Forty-eight hours after asphyxiation, the bilirubin concentrations in blood, CSF, and brain were measured in both study groups. Mean CSF and brain bilirubin levels were significantly higher in the experimental compared to the control group; however, mean serum bilirubin levels were not different. Moreover, in the experimental group a significant correlation existed between CSF and brain bilirubin concentrations. In conclusion, an asphyxiatic insult resulted in disruption of both the blood-brain and the blood-CSF barriers.
In a study involving 25 preterm infants, obstetric clinical age (standard gestational age) was determined by history, physical examination, and ultrasonographic evaluation. Postnatally, these infants were then evaluated using the Dubowitz Scoring System (DSS) for gestational age assessment. The DSS, as administered by us, significantly overestimated gestational age compared with the standard gestational age (mean +/- 1 SD: 34.2 +/- 2.9 vs 32.5 +/- 3.9 weeks, respectively) in preterm infants. To illustrate, the gestational ages of 13 newborns (52%) in the total study group were each overestimated by more than two weeks. This percentage increased to 75% among the 16 infants whose gestational ages were less than 34 weeks (by standard gestational age). When the standard gestational age was underestimated by the DSS, this difference never exceeded two weeks. These findings suggest that the present system of postnatal assessment of gestational age in preterm infants needs further investigation.
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To determine the neonatal body measurement that best predicts insertional umbilical catheter lengths, we studied two commonly used parameters--shoulder-to-umbilicus length and total body length--and two new parameters--suprasternal notch-pubic symphysis length and birth weight (BW)--on 43 umbilical artery (UA) and ten umbilical vein (UV) catheterizations. The new parameters showed better correlations than the currently used ones. The BW variable, with the highest coefficient of correlation among all four parameters, was applied prospectively in 25 UA and 16 UV catheter insertions. All catheter tips thus placed were found to be in acceptable positions. Although any one of the four parameters can be used clinically, we prefer the BW parameter for its reliability, reproducibility, and ability to be estimated in emergency settings. The modified regression (estimating) equations utilizing BW are as follows: UA catheter length = 3 X BW + 9; UV catheter length = 1/2 X UA line calculation + 1, in which lengths are measured in centimeters and BW is measured in kilograms.
Gender-specific newborn rats were randomized into two treatment groups: experimental (received steroid) and control (administered normal saline). Steroid treatment was initiated on 2nd day of life. Hydrocortisone sodium succinate at 10 mg/kg was administered intraperitoneally every 12 hours for four doses. On 3rd day of life, after the last dosage, all rats were asphyxiated once in a standardized manner. Steroids had no effect in improving respiratory tolerance. The experimental group in both genders, but more predominantly in females, gained less body weight compared to control littermates. However, no differences in somatic growth was detected between genders. This finding in newborn rats is in contrast to older rats where males are reported to be less resistant to the growth retarding effects of steroids.