Search PubMed⌕ Search

Biomedical subjects

S Harada

Publications and source records attributed to S Harada.

At least 613 records · Page 34Linked to original sources
PubMed1984

Different enzymatic oscillations in vivo caused by the stereoisomers of an aminopeptidase inhibitor, bestatin.

The present study was undertaken to compare the enzymatic oscillations induced in three major organs, spleen, kidney, and liver, of mice by the active and inactive forms of an aminopeptidase inhibitor, bestatin. Although bestatin caused sine curve-type oscillations of enzymatic activities in spleen and kidney, its isomer, possessing no enzyme-inhibiting actions and no biological actions, did not show any typical enzymatic changes. Such typical oscillations were not elicited by either one of those two agents in liver, in spite of the apparent difference in the type of oscillations induced by them in this organ. These observations were taken to indicate that the enzymatic oscillations in vivo caused by bestatin are closely related to its aminopeptidase-inhibiting actions seen in vitro and that the immunomodifying actions of this agent are based on its effects on enzymes sensitive to it, possibly involving immunoresponsive cells.

Aminopeptidases↗
PubMed1983

Scanning electron microscopic observation of the parasitic forms of Fonsecaea pedrosoi in a human skin lesion.

The parasitic form of Fonsecaea pedrosoi in the superficial hyperkeratotic layer of the skin, in a patient with chromoblastomycosis, was observed by a scanning electron microscope using some technical improvements. The fungus elements were comprised of branched septate hyphae with spherical cells and sclerotic cells. It was observed that the sclerotic cells, divided into two or three parts, formed a germ tube.

Aged↗
PubMed1983

Effects of beta-adrenoceptor blocking agents of N-tertiary butyl derivatives on maximum upstroke velocity of action potential in guinea-pig papillary muscles.

The effects of bufetolol (27.8-138.9 mumol/l), bunitrolol (70.2-351.1 mumol/l), bupranolol (16.2-100 mumol/l), carteolol (60.7-607 mumol/l), D32 (17.3-100 mumol/l), penbutolol (1.5-29.4 mumol/l) and timolol (115.5 and 231.2 mumol/l) on action potentials were investigated in isolated guinea-pig papillary muscles. All these beta-adrenoceptor blocking agents of teritary butyl aminopropranol derivatives produced a concentration-dependent reduction of Vmax at driving rates of 1 Hz, 0.027 Hz and 4 Hz. The reduction was frequency-dependent but at all the rates penbutolol was highest in potency, as estimated by ED30 (0.027 Hz) and ED 50 values (1 and 4 Hz), followed by bupranolol, D-32, bufetolol and bunitrolol. These were followed in turn by timolol and carteolol in ED30 at 0.027 Hz and ED50 at 1 Hz, but by carteolol and timolol in ED50 at 4 Hz. Each log (1/ED) value is a linear function of log n-octanol/water partition coefficient (log P). The slope and intercept (the value at log P = 0) of the line of log (1/ED50) at 4 Hz are steeper and higher, respectively, than those of the lines at the other frequencies. The time course of recovery of Vmax during diastole was studied by assessing Vmax in premature responses at 0.027 Hz, being approximated by a single exponential function. The time constants of recovery (tau) and intercepts (Ao: the value extrapolated to the time of APD90 of the conditioning responses) at the level of ED50 and at 100 mumol/l of the drugs were thus estimated.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1983

Comparative study of erythrocyte aldehyde dehydrogenase in alcoholics and control subjects.

Human erythrocyte aldehyde dehydrogenase (ALDH, EC 1.2.1.3) shows a single activity band on starch gel electrophoresis and isoelectric focusing in polyacrylamide gel (pI = 5.0-5.3). The erythrocyte enzyme is identical with the slower migrating, disulfiram-sensitive human liver ALDH isozyme II. Significantly decreased activity of erythrocyte ALDH was observed in chronic alcoholics when compared with healthy controls and non-alcoholic psychiatric and gastrointestinal patients. The measurement of ALDH in erythrocyte lysates may offer yet another sensitive and specific biochemical marker of alcoholism.

Alcoholism↗
PubMed1983

Blood ethanol and acetaldehyde levels in Japanese alcoholics and controls.

Aldehyde dehydrogenase (ALDH) isozyme I deficiency in hair root samples from 105 healthy individuals and 72 alcoholics was determined using isoelectric focusing. From these individuals, 12 male alcoholics (2 with ALDH isozyme I deficiency and 10 normal) and 45 healthy controls (18 with ALDH isozyme I deficiency and 27 normal) were investigated for their blood ethanol and acetaldehyde levels by gas chromatography after an acute dose of alcohol (0.5 g ethanol/kg body wt.). Peak blood ethanol values of about 10 mmol/l were attained after 1 hour both in alcoholics and normal controls irrespective of their ALDH type. There was no significant difference in the blood ethanol level during the 5 hr post-drinking period in both the groups. Peak blood acetaldehyde concentration was significantly higher in healthy controls and alcoholics deficient in ALDH isozyme I after alcohol drinking (about 30 micro-mmol/l) than in individuals with normal ALDH isozyme I (3 micro-mmol/l). However, no significant difference in blood acetaldehyde was observed between alcoholics and controls.

Acetaldehyde↗
PubMed1983

Aldehyde dehydrogenase isozyme variation and alcoholism in Japan.

Aldehyde dehydrogenase (ALDH) isozyme composition in hair roots was determined using isoelectric focusing in 105 healthy individuals, 175 alcoholics, 86 schizophrenics and 47 drug dependents. The incidence of ALDH isozyme I deficiency in healthy populations in Japan was found to be about 40%. Among alcoholics, however, only 2.3% individuals had the isozyme deficiency. There was no difference between normal controls, schizophrenics and drug dependents regarding the incidence of ALDH isozyme I deficiency. These observations indicate a possible protective role of ALDH isozymes against alcoholism. The higher frequency of ALDH isozyme I deficiency in Japanese may explain why alcoholism in Japan has been less frequent than in European and North American countries. ALDH isozyme II was found in most of the tissues and erythrocytes. A higher frequency of individuals possessing lower ALDH activity in hemolysates was observed in alcoholics than that in controls. The activity of acid phosphatase was also reduced in alcoholics. Alcohol abuse might result in disturbed protein synthesis in the erythrocytes.

Acid Phosphatase↗
PubMed1983

Pharmacogenetics of alcohol sensitivity.

The metabolism of acetaldehyde has received considerable attention in the past few years due to its toxic effects and possible importance in pharmacogenetics. Recent studies have demonstrated rapid progress concerning the multiple molecular forms of ADH and ALDH and their genetic variants. The isozymes of ALDH may play an important role in the biological sensitivity to alcohol in certain ethnic groups and also in the pathogenesis of alcohol related organ damage. A protective effect of ALDH I deficiency against alcoholism seems to exist in Japanese.

Acetaldehyde↗
PubMed1983

Lymphocyte abnormalities in preleukemia--I. Decreased NK activity, anomalous immunoregulatory cell subsets and deficient EBV receptors.

The development of acute non-lymphocytic leukemia is preceded by a set of symptoms described as the preleukemia syndrome. Six patients who fulfilled the criteria for this preleukemia syndrome have been evaluated for abnormalities in the lymphocyte population. The NK cell activity was reduced, the immunoregulatory cell populations were numerically abnormal, and the B cell subpopulation was deficient in EBV receptors. Thus, in addition to the abnormalities in the myeloid populations, there are serious defects in the lymphoid systems of preleukemic patients.

Adult↗
PubMed1983

Synthesis and biological activities of the Z isomers of carbapenem antibiotics.

Naturally occurring carbapenem antibiotics having a double bond in the side chain, when refluxed in chloroform containing quarternary alkylammonium halides, were converted into Z isomers in high yields. The mechanism of this new equilibration involves intramolecular proton transfer from the carboxylic acid to the carbon alpha to the sulfur atom in the side chain as shown by deuterium-labeling experiments. Some Z isomers showed stronger protective effects in mice infected by Escherichia coli O-111 and more potent synergistic activities with cefotiam in mice infected by Proteus vulgaris GN4815 than did the naturally occurring E isomers. The decomposition rates of the Z isomers in mouse kidney homogenates were about 3-fold slower than those of the E isomers.

Animals↗
PubMed1983

Synthesis and biological activities of the Z isomers of carbapenem antibiotics.

Naturally occurring carbapenem antibiotics having a double bond in the side chain, when refluxed in chloroform containing quarternary alkylammonium halides, were converted into Z isomers in high yields. The mechanism of this new equilibration involves intramolecular proton transfer from the carboxylic acid to the carbon alpha to the sulfur atom in the side chain as shown by deuterium-labeling experiments. Some Z isomers showed stronger protective effects in mice infected by Escherichia coli O-111 and more potent synergistic activities with cefotiam in mice infected by Proteus vulgaris GN4815 than did the naturally occurring E isomers. The decomposition rates of the Z isomers in mouse kidney homogenates were about 3-fold slower than those of the E isomers.

Animals↗
PubMed1983

The role of alcohol dehydrogenase and aldehyde dehydrogenase isozymes in alcohol metabolism, alcohol sensitivity, and alcoholism.

Isozymes of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were studied in human organs and tissues using sensitive analytical techniques. Both ADH and ALDH showed an extensive polymorphism among different racial groups. In liver extracts and other tissues of Japanese an isozyme of ALDH (ALDH I) with a low Km for acetaldehyde was found to be deficient. The ALDH isozyme deficiency might account for the marked initial sensitivity to alcohol in Orientals owing to their impaired acetaldehyde oxidizing capacity. Significantly low erythrocyte ALDH activity was noted more frequently in chronic alcoholics than in healthy controls. After subcellular fractionation of livers from alcoholics a preferential damage of mitochondrial ALDH isozyme was observed. The metabolism of acetaldehyde has received considerable attention in the past few years, owing to the toxic effects of this substance. Rapid progress has been made in the understanding of the multiple molecular forms of ADH and ALDH in human tissues. Our recent studies have demonstrated that the isozymes of ALDH may play an important role in the pathogenesis of alcohol-related organ damage and in the biological sensitivity to alcohol in certain ethnic groups. A possible protection of ALDH I deficiency against alcoholism in Japanese has been discussed. More recent reports [Imprain et al, 1982; Jones, 1982] indicate that, in addition to the enzymatically active ALDH II, tissues from Orientals deficient in ALDH I isozyme contain enzymatically inactive, immunologically cross-reactive material homologous with ALDH I. Thus, the absence of ALDH I isozyme is not due to a regulatory mutation, a gene deletion, or a nonsense mutation, but probably results from a structural mutation.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohol Dehydrogenase↗
PubMed1983

[Clinical experience with cefoxitin in the field of gastrointestinal surgery].

A total of 20 patients involved in gastrointestinal surgery was treated with cefoxitin (CFX). Ten patients were treated for postoperative infections and the other 10 patients were given CFX to prevent postoperative infections. The following results were obtained: In 10 patients treated for postoperative infections, 5 responses were judged "excellent", 1 "good", 2 "fair", 1 "poor" and 1 "unknown". In 25 strains of bacteria isolated from these patients, 21 were eradicated, 3 were replaced and 1 was unknown. In 10 patients given CFX for prevention of postoperative infections, 9 were judged "excellent" and the remaining 1 "good". No side effects were observed in any of the patients treated with CFX.

Adult↗
PubMed1983

[Safety evaluation of micronomicin IV. Acute toxicity in rats, rabbits and dogs after drip intravenous infusion].

Micronomicin (MCR) is a new aminoglycoside antibiotic produced by Micromonospora sagamiensis var. nonreducans which was isolated from soil collected at Sagamihara City by Nara et al. This antibiotic shows a close similarity to gentamicin C components in physical and chemical properties. The antibacterial activity of MCR is broad-spectrum and almost equal to that of gentamicin C complex. MCR exhibits particularly high activity against Pseudomonas, Proteus, Klebsiella pneumoniae, Serratia, etc, as well as against some Pseudomonas aeruginosa strains resistant to gentamicin C1a. Toxicological studies of MCR were carried out for safety evaluation as follows: Studies were carried out to assess acute toxicity, when administered in 1 hour by drip intravenous infusion to Wistar rats, Japanese White rabbits and Beagle dogs. The results of the studies are summarised as follows: There was no difference on acute toxicity between drip intravenous infusion (d.i.v.) and intramuscular injection (i.m.) in rats. However, acute toxicity of d.i.v. was less than that of bolus intravenous administration (i.v.) in rats. Acute toxicity of d.i.v. was stronger than that of i.m. in dogs when administered in rats. Acute toxicity varied with species, and it was ranked in rabbits not equal to dogs greater than rats. There was no difference on symptoms between d.i.v. and i.m.

Aminoglycosides↗
PubMed1983

[Safety evaluation of micronomicin V. Subacute toxicity in rats after intravenous injection].

Micronomicin (MCR) is a new aminoglycoside antibiotic produced by Micromonospora sagamiensis var. nonreducans which was isolated from soil collected at Sagamihara City by Nara et al. This antibiotic shows a close similarity to gentamicin C components in physical and chemical properties. The antibacterial activity of MCR is broad-spectrum and almost equal to that of gentamicin C complex. MCR exhibits particularly high activity against Pseudomonas, Proteus, Klebsiella pneumoniae, Serratia, etc. as well as against some Pseudomonas aeruginosa strains resistant to gentamicin C1a. Toxicological studies of MCR in rats were carried out by intravenous injection for safety evaluation. Study on subacute toxicity: Wistar rats were injected intravenously with MCR at the dose levels of 4, 10, 25, 63 mg/kg and 100 mg/kg for 30 days. The results of the studies are as follows: In the subacute toxicity study, animals died at the dose level of 100 mg/kg (10 out of 30 animals). Main changes observed were renal disorders and ataxia which showed a close similarity to those seen in intramuscular toxicity studies in rats. The renal histological disorders occurred mainly at the dose levels of 25 mg/kg and over, but they were slight at the dose levels of 25 mg/kg. Ataxia was observed at the dose levels of 63 mg/kg and over, but its grade was slight at the dose level of 63 mg/kg. The maximum safety dose was equal to in the intramuscular subacute toxicity in rats, 10 mg/kg.

Aminoglycosides↗