Exercise ECG testing using different protocols in asymptomatic healthy young subjects.

Thirty four healthy young male subjects performed symptom limited exercise on Bruce protocol on treadmill machine. Hyperventilation induced labile repolarisation ST-T abnormalities were observed in 2 whereas exercise induced ST changes (upsloping ST depression in 4 and horizontal ST depression in 1) were observed in 5 additional candidates. Changes were unaccompanied by symptoms or signs and quickly reverted back to normal within 30 sec. of cessation of exercise and hence were 'probable false positives'. Sixty-eight age and sex matched volunteers (including former 34) when exercised on Master's stepper, failed to reveal any change probably due to the lack of continuous ECG monitoring device.

Studies on circadian periodicity of plasma, breast milk and urinary calcium in lactating Indian women.

Circadian periodicity of plasma, breast milk and urinary calcium was studied in six lactating Indian women. Peak plasma calcium was recorded at 2000 with a progressive decline during the rest of the period reaching a minimum at 0800. Breast milk calcium was found to be maximum at 0200 and decreased consistently reaching a minimum at 2000. Maximum urinary calcium was observed at 0600 to 1200 with a minimum excretion at 1800 to 0000. A marked circadian variation during the 24 hour period was noticed in plasma, breast milk and urinary calcium confirming a definite rhythm of endogenous body calcium in lactating Indian women. Thus, there we found significant diurnal rhythm in body calcium at all levels and each of them might be initiating the other rhythm, partly governed by the day-night cycle in tropical conditions.

Effect of melatonin on glucose tolerance and blood glucose circadian rhythm in rabbits.

Experimental studies on pinealectomized animals and in vitro studies using pancreatic tissue, have indicated that the pineal gland has a suppressive effect on the pancreatic B cells which secrete insulin. In this study, melatonin, was injected into rabbits and a statistically significant decrease in glucose tolerance was noted. The effect of melatonin in influencing the circadian rhythm of blood glucose was also studied in rabbits. Results showed that melatonin influences the circadian rhythm leading to a shift in the occurrence of minimum levels from 16.00 hr to 04.00 hr (next day) during fasting and from 16.00 hr to 20.00 hr during feeding. Also melatonin treatment lead to a statistically significant rise in blood glucose levels. It is probable that melatonin administration reduces glucose tolerance and influences the blood glucose circadian rhythm mainly through its effects on insulin release by pancreatic B cells.

Concentrations of Calcium, inorganic phosphorus and alkaline phosphatase in the sera of lactating women in North India.

Serum calcium, inorganic phosphorus and alkaline phosphatase (SAP) have been determined in 75 lactating women and 25 controls. 25 lactating women were re-investigated after administration of calcium and vitamin D supplements of 1 month. Lactating women showed statistically significant hypocalcaemia and raised SAP. However, the elevation of the enzyme level was significantly lower in women with milk intakes of more than 1/2 litre per day and in those in later months of lactation. The effects of calcium and vitamin D supplementation supported a diagnosis of osteomalacia in a large percentage of lactating women.

Effect of light and exhaustive ergometric exercise on blood sugar, total cholesterol and pH in untrained young human subjects.

Light and exhaustive ergometric exercise in untrained male and female medical students in the age group 18-21 years resulted in significant lowering of the blood sugar, cholesterol and pH. Females exhibited hypoglycemia of slightly greater magnitude as compared to male subjects and during both the exercises, however, such sex differences were not observed for changes in cholesterol and pH.