Transfer lung factor for Co (TLCO) and its components (DM & VC) in flour mill workers.

Tlco, Kco (Tlco/Va), Va, Vc and Dm were measured in 25 flour mill workers (non-smoker 9, smoker 16) and 50 healthy control subjects (25 non-smoker, 25 smoker) of similar anthropometric parameters and socio-economic status. Tlco (P < 0.05) was decreased significantly and rest of the parameters were decreased insignificantly in flour mill workers as compared to control subjects. In non-smoker flour mill workers none of the parameters altered significantly as compared to non-smoker control subjects. Statistically significant reduction was seen in smoker workers only in Tlco (P < 0.05) and its component Dm (P < 0.05) as compared to smoker control subjects. Further it has been observed that less duration of flour dust exposure (< 5 years) in all flour mill workers and smoker flour mill workers caused negligible fall in Tlco, whereas longer duration of flour dust exposure (> 5 years) in both the groups caused highly significant fall in Tlco (P < 0.01) which was contributed to by highly significant fall in Dm (P < 0.001).

Effect of graded doses of naloxone on renal function in canine hemorrhagic shock.

All the parameters of renal function (inulin clearance, para amino hippuric acid clearance and urine flow) which were depressed during experimentally induced hemorrhagic shock in dogs improved significantly in addition to improvement in mean arterial pressure (MAP) after bolus administration (iv) of 1 or 2 mg/kg naloxone. A smaller dose (0.5 mg/kg) of naloxone, however, did not improve the renal function. Even renal arterial injection of the same dose of naloxone showed no improvement in the renal function. In both these cases the improvement in the MAP was significantly less as compared to other groups of animals which received 1 or 2 mg/kg naloxone. It may be concluded that (a) naloxone at doses of 1 or 2 mg/kg improved the renal function by improving MAP and (b) naloxone has no direct action on renal vasculature.

Effect of vitamin D supplementation in lactating rats on the neonatal growth.

In lactating rats consuming a commercial diet adequate in calcium, phosphorus and vitamin D, the effect of supplementation of 3000 IU and 7,500 IU of vitamin D3 on the lactational performance of the dams and soft tissue and skeletal growth in the pups has been investigated. On 28th day of age, the pups in the supplemented groups were significantly heavier than in the control group. Study of the indices of cellular growth in the liver and gastrocnemius muscle revealed that the increase in the soft tissue weight was due to a significant increase in protein, RNA and DNA contents (cellular hyperplasia) without any change in protein/DNA ratio (cell size). In the tibia, compared to controls, the dry bone weight and ash weight were more in the supplemented groups, but ash weight/dry bone weight ratio was not altered. The improvement in the neonatal growth was most probably due to the greater milk yield observed in the dams in supplemented groups and not due to any anabolic effect in the pups since direct administration of 500 IU or 1,000 IU of vitamin D3 in 10 day old pups did not increase their body weight.

Effect of naloxone on renal cortical microcirculation in haemorrhagic shock.

In order to assess the effect of opioid receptor antagonists, naloxone and noradrenaline, on renal cortical microcirculation, India ink infusion was made through the renal artery, one hour after treatment with each drug, in dogs subjected to haemorrhagic shock. Naloxone (1 mg/kg) treatment showed a dual beneficial effect of significant improvement (P < 0·001) in the mean arterial pressure without increasing the renal resistance as indicated by the presence of ink particles in about 75% of the cortical glomeruli. However, in the case of noradrenaline (2 μg/kg/min)-treated animals, although mean arterial pressure increased significantly (P < 0·001) only very few glomeruli (25%) in the cortical region showed ink particles, demonstrating severe vasoconstriction. In the control group infused only with saline, although most of the glomeruli (92%) were filled with ink particles, there was a significant decline in the mean arterial pressure (P < 0·001).

Effect of cold challenge on alveolar capillary blood volume in normal individuals.

The effect of immersion of both the hands and the feet in water at 10 degrees C on lung transfer factor for carbon monoxide (Tlco) and on pulmonary capillary blood volume (Vc) was investigated in 20 normal young adult males immediately, 60 min and 120 min after the end of the cold challenge. Vc was significantly reduced immediately and the reduction was aggravated at 60 min. Tlco was significantly reduced only at 60 min. All the values returned to baseline at 120 min. It is concluded that the cold-induced changes in Tlco and Vc are physiological responses and not unique to patients with Raynaud's phenomenon as suggested by some workers.

Comparison of effects of naloxone and catecholamines on acid-base balance in canine hemorrhagic shock.

The present study was conducted to compare the effect of naloxone, an opiate receptor antagonist, with catecholamines on acid-base status and survival in dogs subjected to hemorrhagic shock. Arterial lactic acid concentration which had increased during hemorrhage, decreased significantly (P less than 0.05) in naloxone treated animals but increased further in catecholamine treated dogs. Blood bicarbonate concentration and PCO2 which had markedly decreased 1 hr after hemorrhage recovered significantly (P less than 0.05) in naloxone group of animals. On the other hand bicarbonate and pH declined further in noradrenaline group and remained unchanged in dopamine group. These results as well as better survival rate observed in naloxone treated animals suggest the superiority of naloxone over dopamine and noradrenaline, as an adjunct to blood transfusion in the treatment of hemorrhagic shock.

Response of lung transfer components to grades of smoking.

Pulmonary functions were studied in 50 healthy, asymptomatic, 20 to 47 years, male smokers along with 50 healthy non-smokers matched for age, height, socio-economic status and physical activity. Smokers consumed 2-30 cigarettes per day with duration of smoking ranging from 2 to 26 years. In smokers FEF, V75. PEF and MVV were significantly reduced whereas FRC was increased significantly. Pulmonary diffusion function as assessed by TLCO showed significant reduction. While Vc showed progressive decrease with increasing duration and quantity of smoking, DM increased in the beginning but gradually declined later. TLCO showed a better negative correlation with quantity than with duration of smoking even when the effect of other factors was excluded. Decrease in TLCO is probably due to bronchoconstriction and reflex vasospasm of pulmonary vasculature. Co-efficient of diffusion KCO was also decreased in smokers.

Ventilatory and diffusion studies in smoker and non smoker flour-mill workers.

Various pulmonary function tests, FVC, FEV1/FVC%, PEFR, EFR25-75, MVV and Tlco were measured in 25 asymptomatic male flour mill workers and 50 healthy subjects not working at flour mill, to assess the effect of flour dust on lungs. All the subjects of different groups were well matched in their anthropometeric parameters and socio economic status. In smoker flour mill workers significant reduction was present in both ventilatory and diffusion functions of lungs, which was more pronounced in subjects who consumed larger quantity of tobacco and were exposed to flour dust for longer duration. On the other hand deterioration of pulmonary functions in non smoker flour mill workers was found to be statistically not significant. The relative strength of both the parameters viz tobacco and flour dust for impairment of pulmonary functions is discussed for being a pointer to further studies.

Amygdalar injections of vasopressin and its antagonist do not disrupt the circadian rhythm of food and water intake in the rat.

There is an indication that areas of the brain other than the suprachiasmatic nuclei (SCN), the known neural circadian pacemaker, are involved in the control of circadian rhythms. The present study investigated the role of amygdala in the circadian rhythms of food and water intake. Vasopressin and its antagonist d(CH2)5Tyr(Me)AVP were injected into the amygdala bilaterally through chronically implanted stainless steel cannulae. The results of the study have shown that neither vasopressin nor its antagonist d(CH2)5Tyr(Me)AVP alters the circadian rhythm of food and water intake thereby showing that vasopressinergic neurons/projections to amygdala are not involved in the control of circadian rhythms of food and water intake and amygdala is not likely to be an additional oscillator.

Effect of acute environmental heat stress on urinary water and electrolyte excretion in the rat.

Plasma cortisol and urinary excretion of water, sodium, potassium, calcium and magnesium have been studied in the rat after application of heat stress. There was a significant increase in plasma cortisol level after exposure to heat. During heat stress complete cessation of urine formation was observed. In the next 30 min there was statistically significant increase in the urinary excretion of water, sodium and calcium but not of potassium and magnesium. Urinary calcium/magnesium ratio was also significantly elevated. The increase in urinary water and electrolyte excretion seemed to be mediated through prostaglandins since it could be abolished by administration of indomethacin prior to the application of heat stress. On the basis of these results, the possible role of heat stress in the genesis of urolithiasis has been discussed.

Pulmonary diffusion capacity for Co at varying alveolar oxygen tensions and different alveolar volumes.

In six healthy nonsmoker volunteers pulmonary diffusion capacity for Co (DLCO) was determined by single breath holding technique. Multiple measurements of DLCO were taken with PAO2 from 70 to 610 mm Hg, out of which at least 10 tests were performed between 100 to 140 mm Hg. A wide and non uniform inverse relationship was found between DLCO and PAO2 from 70 to 610 mm Hg. In narrow range of 100-140 mm Hg, a highly significant linear negative correlation was found. To find out corrected DLCO at PAO2 120 mm Hg, expressed as DLCO120, a correction factor of 0.45% for each mm Hg change in PAO2 should be applied to measured DLCO inversely. By regulating inspiratory volume, DLCO was studied at different alveolar volumes and there was a direct positive correlation between them. DLCO should be measured at maximum alveolar volume, as with one percent fall in VA there is 0.69% decrease in DLCO. This new method of expressing DLCO as DLCO120 at maximal effective alveolar volume will be more useful in studying the effects of factors affecting DLCO and for interlaboratory comparison.

Acute effects of neurogenic stress on urinary electrolyte excretion.

Plasma Cortisol and urinary excretion of water, sodium, potassium, calcium and magnesium have been studied in the rat after application of 2 types of neurogenic stress:--(a) tight rubber band tourniquet and (b) electric shock. Plasma cortisol levels increased significantly after application of either type of stress. During both type of stress, there was statistically significant increase in the urinary excretion of water, sodium and calcium but not of potassium and magnesium. Urinary calcium/magnesium ratio was also significantly elevated. The results suggest that stress may be one of the factors involved in the genesis of urolithiasis.

Role of H-reflex latency studies in the diagnosis of subclinical diabetic neuropathy.

Motor conduction velocity (MCV) in the median, ulnar and peroneal nerves and H-reflex studies have been conducted in 50 diabetics aged 20-65 years and 25 controls. MCV in the upper limb was below the normal range in 16% of diabetics. 28% diabetics showed abnormal MCV in the peroneal nerve. H-reflex abnormality consisting of either prolonged latency or its complete absence could be observed in 54% of diabetics. The results indicate the greater sensitivity of H-reflex in the detection of sub-clinical diabetic neuropathy. Greater prevalence of neuropathy in the early onset diabetes than in the late onset type is also suggested.