Effect of ambient temperature changes in autonomic responses.

Effect of moderate changes in ambient temperature on autonomic activity was studied in male medical students. Autonomic function tests, i.e. Valsalva ratio, standing-to-lying ratio (S/L ratio), cold pressor response (CPR) and resting heart rate were carried out at two different ambient temperatures of 37.45 degrees +/- 0.52 degrees C and 32.54 degrees +/- 0.65 degrees C. At lower ambient temperature, there was decrease in the Valsalva ratio, increase in S/L ratio and lesser augmentation of systolic and diastolic blood pressure in CPR as compared to that at higher ambient temperature, indicating alteration in autonomic response with moderate changes in ambient temperature.

Histamine and mast cell study in the gastric tissue of south Indian patients suffering from duodenal ulcer with pyloric stenosis.

Patients undergoing surgery for pyloric stenosis secondary to duodenal ulcer were the subjects for the study. Two pieces of full thickness gastric wall (all coats) were obtained at laparotomy. The pieces were immediately split into two halves. One of these was used for histamine assay where as the other was used to study the mast cell population. Histamine content and mast cell population was found to be less in gastric mucosa of our patients as compared to values from normal human gastric mucosa. There was lack of correlation between mast cell population and histamine content which suggests that there could be some other storage sites for histamine.

The effect of vagotomy and hydrocortisone administration on pulmonary surfactant activity in adult albino rats.

The role of vagus and hydrocortisone in the regulation of lung surfactant was studied in adult albino rats. Dynamic surface tension and phospholipid content were measured in the lung wash for estimating surfactant activity. The results indicate that vagotomy significantly decreases the surfactant activity whereas hydrocortisone does not alter it. But when hydrocortisone was administered prior to vagotomy it could prevent the decrease in surfactant activity. Thus it is concluded the regulation of lung surfactant in the adult lung is mainly by vagus nerve and hydrocortisone as such has no role but in the absence of vagal regulation hydrocortisone could maintain normal lung surfactant activity.

Effect of cowdung smoke inhalation on E.C.G. of rats.

The present study was conducted on 20 adult albino rats divided into group I (n = 10) and group II (n = 10). Group I animals were exposed to cowdung smoke for 60 min twice a day for a period of 75 days whereas group II served as control. ECG of control rats was essentially similar to that of man. ST segment was absent, Q wave absent or rudimentary and the mean QRS axis + 45 degrees. Rats exposed to cowdung smoke revealed a significant increase in PR interval and a mean QRS of + 117.5 degrees. Our results indicate that inhalation of cowdung smoke leads to conduction defects and right axis deviation.