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Biomedical subjects

S Arai

Publications and source records attributed to S Arai.

At least 469 records · Page 26Linked to original sources
PubMed1977

Rapid microwave fixation of rat brain.

A new microwave device which inactivates brain enzymes rapidly and uniformly is described. From the results obtained with microwave irradiation at two power levels (0.8 kW and 4.5 kW), it has been demonstrated that the high power microwave irradiation has several advantages over the low power irradiation. In its application to neurochemical studies, significant increase in the DOPAC level was found in the irradiated brain, while there were no statistical differences in the levels of NE, DA, 5-HT and 5-HIAA between microwave irradiation and decapitation. Significant increase in the Ach level and marked reduction of the choline level were observed after microwave irradiation. There were no significant differences in the level of cyclic GMP in the brain between the two methods of sacrifice, while significant reduction of the cyclic AMP level was observed in the irradiated brain.

Acetylcholinesterase↗
PubMed1977

Effect of acute unilateral renal denervation on tubular sodium reabsorption in the dog.

The effects of acute denervation of the kidney on renal tubular sodium and water excretion were studied in anesthetized, hypophysectomized, and cortisone-treated mongrel dogs during stable water diuresis produced by the infusion of 2.5% dextrose. In all experiments, denervation natriuresis, and diuresis were observed without significant change in glomerular filtration rate (GRF) and renal plasma flow (RPF). Fractional sodium delivery to the distal nephron (CNa + CH2O/100 ml GFR) and fractional free water clearance (CH23/100 ml GFR) was significantly greater in the denervated kidney compared with the innervated kidney (9.6+/-1.2 vs. 6.7+/-0.9% and 8.8+/-1.2 vs. 6.5+/-0.8%, respectively). Distal tubular sodium reabsorption (CH2O/(CNa + CH2O)) was not significantly different. We conclude that renal denervation primarily affects the proximal tubule as manifested by a decrease in the reabsorption of sodium and water. A small effect of denervation on the distal nephron is not completely ruled out.

Animals↗
PubMed1976

Studies on delayed hypersensitivity of antigens isolated from Mycoplasma pneumoniae cells.

Cells of Mycoplasma pneumoniae Mac strain were fractionated into acetone-soluble and insoluble fractions. Acetone-insoluble fractions were digested with pronase and further purified by chromatography on Sephadex G-75, yielding three water-soluble fractions which were free from lipid and consisted mainly of polysaccharide-protein complex. All these water-soluble fractions possessed eliciting antigenicity to delayed hypersensitivity for M. pneumoniae as measured by skin reactions and macrophage migration inhibition tests, but not to complement-fixing antibodies. In contrast, the acetone-soluble fraction was reactive with the complement-fixing antibodies but not for the delayed hypersensitivity.

Acetone↗
PubMed1976

Distribution of intrarenal blood flow after renal denervation in the dog.

The effect of acute denervation of the kidney on renal sodium and water excretion, and hemodynamics including intrarenal blood flow, was studied in anesthetized dogs. The intrarenal blood flow was measured by the radioactive microsphere method. In all experiments denervation natriuresis and diuresis was observed without significant change in glomerular filtration rate, renal blood flow and distribution of intrarenal blood flow. There was, however, an associated increase in potassium excretion. We suggest that denervation natriuresis and diuresis may be caused by the elimination of a direct nervous control of sodium and water reabsorption.

Animals↗
PubMed1976

Hypertension and plasma renin activity in experimentally induced chronic pyelonephritis.

The present authors conducted a series of experiments with mongrel dogs, in which unilateral chronic pyelonephritis was induced and postoperative changes in blood pressure and plasma renin activity were observed over a period of 3 months. The pyelonephritis infection was brought about by a method involving vesicoureteral reflux and ureteral dysfunction, as described in a previous paper. Pre- and postoperative levels of systolic pressure were compared, but no definite trends were found for the first 3 weeks after operation. At 30, 60 and 90 days the pressures were found to have risen by 21.2 +/- 14.6 and 17.1 +/- 16.7 mm Hg, respectively. No appreciable change in the plasma renin activity was found, however, at any stage. From these results it was concluded that experimentally induced chronic pyelonephritis in dogs caused a rise in blood pressure. No connection between the pyelonephritis and the renin angiotensin system was found.

Animals↗