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Biomedical subjects

S Hirose

Publications and source records attributed to S Hirose.

At least 901 records · Page 50Linked to original sources
PubMed1975

Demonstration by affinity chromatography of the cell-free synthesis of ribonuclease-specific immunoglobulin.

An immunoglobulin specific for RNase [EC 3.1.4.22] has been synthesized in a cell-free system containing either lymph node microsomes or polysomes or spleen polysomes from rats previously immunized with RNase. The synthesis of anti-RNase immunoglobulin was demonstrated by affinity chromatography using an RNase-Sepharose column. Supporting evidence for the cell-free synthesis of immunoglobulin was obtained by separating the synthesized immunoglobulin from other proteins by DEAE-Sephadex A-25 column chromatography and by neutralization of RNase activity with the separated immunoglobulin. Lymph nodes and spleen had an almost equal capacity to synthesize the immunoglobulin to RNase. Under our experimental conditions, 5 to 15 per cent of the total protein synthesis was directed toward immunoglobulin synthesis.

Adenosine Triphosphate↗
PubMed1975

Effects on ribosomes of the substitution of spermidine or divalent cations for magnesium ions.

The inactivation of rat liver ribosomes (polysomes) resulting from the replacement of bound magnesium by spermidine has been studied using a dialysis method. Inactivation of the ribosomes (polysomes) occurred when more than 40% of the Mg2+ originally bound to ribosomes in the presence of 2 mM Mg2+ was replaced by spermidine. The polypeptide-synthesizing activity of polysomes was retained partially when Mg2+ was replaced by Mn2+ by dialysis. E. coli 30S ribosomal subunits were more resistant to inactivation due to the replacement of Mg2+ by spermidine than the 50S subunits.

Animals↗
PubMed1975

Effect of alcohols on polypeptide chain elongation and aminoacyl-tRNA formation.

The effect of alcohols (methanol, ethanol, and propanol) on polypeptide chain elongation was studied. In the E. coli and rat liver cell-free systems, the optimal concentration of Mg2+ decreased with increase of ethanol concentration, although the maximum polyphenylalanine synthesis decreased. Methanol had almost the same effect as ethanol. Propanol decreased the optimal magnesium concentration, but polyphenylalanine synthetic activity was markedly decreased. The shift of optimal Mg2+ concentration by ethanol was also observed in polylysine and polysome-dependent polypeptide syntheses. Even in the presence of spermidine, ethanol caused the shift of optimal Mg2+ concentration. Ribosome-bound Mg2+ was decreased by the addition of ethanol. A study of the effect of alcohols on aminoacyl-tRNA formation with ten amino acids in the absence of added Mg2+ showed that the formation of arginyl-, leucyl-, and valyl-tRNA was stimulated by the alcohols. Valyl-tRNA formation in the presence of alcohols was completely inhibited by EDTA, while that in the presence of Mg2+ was inhibited slightly by EDTA. No PP1-ATP exchange was observed when alcohol was used as the only stimulant of valyl-tRNA formation.

1-Propanol↗
PubMed1975

Immobilized L-asparginase embedded in fibrin polymer.

Immobilized asparaginase was prepared by embedding asparaginase (which is effective for remission in children with leukemia) into fibrin polymer formed by fibrinogen-fibrin conversion in the presence of thrombin. The immobilized asparaginase film did not dissolve in 6 mol/1 urea, suggesting that blood coagulation factor XIII participates in the cross-linking between fibrins and between fibrin and asparaginase.

Animals↗
PubMed1975

Consequences of reperfusion following acute coronary occlusion.

The sequential effects of reperfusion following acute intracoronary balloon occlusion were investigated in closed-chest anesthetized dogs by simultaneous measurement of hemodynamics and regional metabolism and histopathologic study. Simultaneous regional determinations of myocardial metabolic function were carried out in coronary-occluded and nonoccluded segments of the left ventricle. A 3-hour occlusion of the proximal left anterior descending coronary artery (LAD) resulted in significant decrease in cardiac function. Intitial reperfusion was marked by major washout of metabolites and development of frequently serious arrhythmias. Reperfusion following 3 hours of LAD occlusion led to futher deterioration in hemodynamics and metabolism: 30% of the dogs developed shock. Lactate extraction decreased further in the nonoccluded region and reached production levels in the occluded zone. Potassium loss increased in both zones. Oxygen extraction remained unchanged. Pathophysiologic examination of tissue specimens from the reperfused zone revealed microthrombi, patchy necrosis, fragmentation of myofibrils, vascular congestions, and hemorrhages.

Acute Disease↗
PubMed1975

Application of a live attenuated varicella vaccine to hospitalized children and its protective effect on spread of varicella infection.

Twenty-three hospitalized children with no history of varicella or no detectable complement fixing (CF) antibody, were vaccinated with a live attenuated varicella vaccine (Oka strain) immediately after the occurrence of a case of varicella in a children's ward of hospital. These children suffered from the nephrotic syndrome, nephritis, purulent meningitis, hepatitis etc., and 12 of them were receiving steroid therapy. An antibody response was noticed in all the vaccinated children, with mild fever in 6 and a mild rash in 2 of 6. It was uncertain whether these reactions were due to vaccinatin or to naturally acquired infection modified by vaccination. No other clinical reactions or abnormalities of the blood or urine were detected. Thus the spread of varicella infection was prevented, with the exception of one severe case in an unvaccinated patient. In another trial, 16 children with renal diseases were also vaccinated. All the children showed an immune response with no clinical reactions and no abnormalities in blood and urine examinations. Thus live varicella vaccine (Oka strain) can be used safely and effectively for hospitalized children, and its effectiveness in preventing spread of varicella infection was confirmed.

Animals↗
PubMed1975

A case of watery diarrhea, hypokalemia and hypercalcemia associated with nonulcerogenic islet cell tumor of the pancreas.

A case of watery diarrhea, hypokalemia and hypercalcemia associated with an islet cell tumor was described. A 62-year old man exhibited frequent watery diarrhea and hypokalemia for two years. He had no peptic ulcer and serum gastrin level was normal. His serum calcium was abnormally high and serum phosphate was lowered. He had secretin-like activity in his plasma. Autopsy revealed a small islet cell tumor in the pancreas and several metastatic masses in the liver. Microscopic examination revealed the tumor cell was not beta, alpha nor D cells. By electron microscopy the secretion granules of the tumor cell resembled those of S, M and T cells. It was not possible to decide which of the tree cell types was responsible for the pancreatic cholera.

Adenoma, Islet Cell↗
PubMed1975

Inhibition of polypeptide synthesis by tRNA fractions in rat liver cell-free systems.

The mechanism of inhibition of polypeptide synthesis by the addition of a tRNA fraction in a rat liver cell-free system was studied. The inhibition was found to occur at the step of aminoacyl-tRNA binding to ribosomes, in which aminoacyl-tRNA's were mainly responsible for the inhibition. The addition of EF-1 decreased the inhibition by the tRNA fraction. The tRNA fraction inhibited polypeptide synthesis in a polysome-S100 system under conditions in which poly U- and poly A-dependent polypeptide syntheses were not inhibited. The possibility that the aminoacyl-tRNA inhibitory activity functions through improper binding to the ribosomes in the polysome-S100 system is discussed.

Amino Acyl-tRNA Synthetases↗