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Biomedical subjects

A Hara

Publications and source records attributed to A Hara.

At least 451 records · Page 25Linked to original sources
PubMed1989

[Massive pericardial effusion in a patient with scleroderma with special reference to concentration of alpha-hANP in plasma and pericardial effusion].

A 41-year-old woman was admitted to our hospital because of scleroderma and combined valvular disease (mitral stenosis, aortic regurgitation, tricuspid regurgitation) associated with massive pericardial effusion. Plasma atrial natriuretic peptide (alpha-hANP) level was 130 pg/ml on admission, and increased temporarily with a decrease of pericardial effusion, without significant of changes of pulmonary capillary wedge pressure, pulmonary arterial pressure, right ventricular pressure nor right atrial pressure. These findings suggest that one of the mechanisms of alpha-hANP secretion, a stretch receptor mechanism, is interfered by the massive pericardial effusion. There was no relationship between atrial pressures and plasma alpha-hANP levels in this case. alpha-hANP concentration in pericardial effusion (486 pg/ml) was four to five folds higher than the plasma alpha-hANP levels.

Adult↗
PubMed1989

[Uncommon renal tumor in children].

We experienced six rare cases of solid renal tumor, which include two benign (CMN, MLCN) and four malignant tumors (CCSK 2, MRTK2). CMN is the most common benign solid tumor in the neonate. MLCN has typical US or CT findings manifested by multilocular cysts and thick wall septa. CCSK and MRTK are rare malignant neoplasms, which present characteristic clinical findings such as bone metastasis or intracranial metastasis. It is important for the radiologist to understand those characteristic clinical presentation of these tumors, because differential diagnosis is often impossible just on the basis of imaging.

Age Factors↗
PubMed1989

[Effect of salazosulfapyridine and its metabolites on immunocompetent cells].

Long-term administration of SASP does offer clinical benefit and has a demonstrable disease modifying effect in rheumatoid arthritis, though its mode of action remains obscure. We have studied the in vitro effects of SASP and its metabolites, that is SP, ASA, AcSP and AcASA, on the blast-formation of lymphocytes, the cytotoxic activity of NK cell, the phagocytosis and H2O2 production of monocyte and the fMLP-induced chemotaxis and superoxide anions production of PMNs. We have obtained the following results: (1) the blast-formation of lymphocytes by PHA and Protein A was significantly inhibited by SASP, but not by the metabolites; (2) the cytotoxic activity of the NK cell was inhibited by SP and AcSP, but not by SASP, ASA and AcASA; (3) on monocyte, SP, AcSP and AcASA inhibited phagocytosis, and all of drugs had no effect on the production of H2O2; (4) on PMNs, SASP, SP and ASA significantly inhibited fMLP-induced chemotaxis, and SASP and all of its metabolites significantly inhibited a release of superoxide anions by stimulation of fMLP and PMA; (5) SASP and ASA scavenged superoxide radical at the concentration comparable to clinical doses. In vivo, the above effects may be exhibited in proportion to each blood concentrations of drugs. In particular, it appears that SASP, SP and AcSP play an important role in the therapeutic efficacy in rheumatoid arthritis.

Chemotaxis, Leukocyte↗
PubMed1989

[The indication for lymph node dissection around abdominal aorta in gastric cancer].

In 77 cases with gastric cancer, for which lymph node dissection around the left renal vein was performed in the past 5 years, the sites and routes of metastasis were investigated to determine the indication for dissection around the left renal vein. The rate of metastasis to the lymph nodes around the left renal vein was 23.4%. The typical routes of metastasis were 1) the left lower phrenic route, 2) via the splenic artery, 3) via the celiac artery, 4) via the superior mesenteric artery and 5) the postpancreatic route. Dissection was considered to be indicated for the patient with N2 or more distant lymph node involvement and for cases with carcinoma of the upper part of the stomach or whole stomach with N2 positive lymph node. It was also indicated for N3(+) cases or No. 9(+) cases of carcinoma of the middle and lower parts of the stomach. Needless to say the absence of other non curative factors is required.

Aorta, Abdominal↗
PubMed1989

Effect of long-term treatment with sulfatide on hyperlipidemia and progression of atherosclerosis in WHHL rabbits.

Changes in serum lipids and lipoproteins and progression of atherosclerosis with age were examined in Watanabe heritable hyperlipidemic (WHHL) rabbits with or without treatment with sulfatide. The injection of sulfatide solution caused a reduction of serum triacylglycerols for five months including the period of treatment, but afterwards, failed to lower the level of total cholesterol, triacylglycerols and phospholipids, and to suppress the progression of atherosclerosis. Concentrations of LDL as a major serum lipoprotein in WHHL rabbits with or without the treatment with sulfatide were found to be about 64-fold those of normal rabbits by immunological assay using anti-LDL antiserum, whereas the contents of total cholesterol, triacylglycerols, and phospholipids in WHHL rabbit sera were found to be about 10-fold those of normal rabbits. All WHHL rabbits with or without the treatment with sulfatide contained very small amounts of HDL. Types of apoproteins of isolated LDL and VLDL fractions suggested that the former seemed to be derived from VLDL remnant, and the latter to be derived from chylomicron remnant. It was noted that all WHHL rabbit sera had a significant increased amount of lysophosphatidylcholine, and that the fatty acid composition of total serum lipids had almost no change except for slight decrease in arachidonic acid with age. Pathological examination showed that severe atherosclerotic lesions were not so different between WHHL rabbits with or without treatment with sulfatide at age over 22 months.

Aging↗
PubMed1989

Induction of altered hepatocellular foci of hamster for a possible short-term assay for carcinogens.

Altered hepatocellular foci of hamster were applied for in vivo short-term (8 weeks) assay for detecting carcinogens using dietary exposure of N-2-fluorenylacetamide (FAA) and oral administration of carbon tetrachloride (CCl4). Although no hepatocellular foci were induced by the treatment with either of two agents (FAA and CCl4) or with their combination, many of the lesions appeared in the hamsters with prior administration of carcinogens, i.e., dimethylnitrosamine, diethylnitrosamine and methylazoxymethanol acetate, all of which have been reported to be carcinogenic in hamsters. A small number of these lesions was also present with the pretreatment of other types of carcinogens, i.e., N-methyl-N-nitrosourea, N-methyl-N'-nitro-N-nitrosoguanidine and azaserine. No such foci were available by N-butyl-N-(4-hydroxybutyl)nitrosamine and 3,3'-dichloro-4,4'-diaminodiphenylmethane, both of which are not known to be clearly carcinogenic in hamsters. The results indicate that hepatocellular foci of hamsters are rapidly inducible under the present protocol and imply that this model could be useful as an assay for screening carcinogens of which hamster is susceptible.

2-Acetylaminofluorene↗
PubMed1988

Subcellular distribution and properties of carbonyl reductase in guinea pig lung.

On subcellular fractionation, carbonyl reductase (EC 1.1.1.184) activity in guinea pig lung was found in the mitochondrial, microsomal, and cytosolic fractions; the specific activity in the mitochondrial fraction was more than five times higher than those in the microsomal and cytosolic fractions. Further separation of the mitochondrial fraction on a sucrose gradient revealed that about half of the reductase activity is localized in mitochondria and one-third in a peroxidase-rich fraction. Although carbonyl reductase in both the mitochondrial and microsomal fractions was solubilized effectively by mixing with 1% Triton X-100 and 1 M KCl, the enzyme activity in the mitochondrial fraction was more highly enhanced by the solubilization than was that in the microsomal fraction. Carbonyl reductases were purified to homogeneity from the mitochondrial, microsomal, and cytosolic fractions. The three enzymes were almost identical in catalytic, structural, and immunological properties. Carbonyl reductase, synthesized in a rabbit reticulocyte lysate cell-free system, was apparently the same in molecular size as the subunit of the mature enzyme purified from cytosol. These results indicate that the same enzyme species is localized in the three different subcellular compartments of lung.

Alcohol Oxidoreductases↗
PubMed1988

Differences in neuronal lipid composition between superior cervical ganglia and nodose ganglia of the rat.

The lipid content and composition of rat superior cervical ganglia containing sympathetic motor neurons and nodose ganglia containing parasympathetic sensory neurons were studied for the first time to elucidate the mechanism of the different effects of exogenous gangliosides on these neurons in the culture medium. The ganglioside content of the superior cervical ganglia was almost 3-times that of the nodose ganglia. Although both ganglia contained GM3, GD3, GD1b and GT1b as major gangliosides, the nodose ganglia additionally contained a significant amount of sialosyllactoneotetraosylceramide LM1 (10% of total sialic acids). Contrasting with nodose ganglia, vagus fiber and dorsal root ganglia of rats, superior cervical ganglia had a higher content of sulfatide than galactosylceramide. The phospholipid content was lower in superior cervical ganglia than in nodose ganglia. Superior cervical ganglia contained less ethanolamine plasmalogen and more phosphatidylcholine than nodose ganglia. Sphingomyelin in superior cervical ganglia contained mainly medium-chain fatty acids, while that in nodose ganglia contained mainly longer-chain fatty acids. Differences in the fatty acid composition of glycerophospholipids were also observed. The results indicate that the properties of neuronal cell membranes from superior cervical ganglia and nodose ganglia are quite different, and that the differences may reflect the physiological roles of these ganglia.

Animals↗
PubMed1988

Kinetic mechanism of pulmonary carbonyl reductase.

The kinetic mechanism of guinea-pig lung carbonyl reductase was studied at pH 7 in the forward reaction with five carbonyl substrates and NAD(P)H and in the reverse reaction with propan-2-ol and NAD(P)+. In each case the enzyme mechanism was sequential, and product-inhibition studies were consistent with a di-iso ordered bi bi mechanism, in which NAD(P)H binds to the enzyme first and NAD(P)+ leaves last and the binding of cofactor induces isomerization. The kinetic and binding studies of the cofactors and several inhibitors such as pyrazole, benzoic acid, Cibacron Blue and benzamide indicate that the cofactor and Cibacron Blue bind to the free enzyme whereas the other inhibitors bind to the binary and/or ternary complexes.

1-Propanol↗
PubMed1988

Mouse liver dihydrodiol dehydrogenases. Identity of the predominant and a minor form with 17 beta-hydroxysteroid dehydrogenase and aldehyde reductase.

A major and a minor form of dihydrodiol dehydrogenase were co-purified with 17 beta-hydroxysteroid dehydrogenase and aldehyde reductase, respectively, to apparent homogeneity from liver cytosol of male ddY mice. The activities of dihydrodiol dehydrogenase and testosterone dehydrogenase or aldehyde reductase of the two enzyme forms comigrated electrophoretically. The major form of the enzyme oxidized 17 beta-hydroxysteroids and nonsteroidal alicyclic alcohols and reduced 17-ketosteroids and various synthetic carbonyl compounds, showing higher affinity for steroids than for xenobiotics. The activity of this enzyme form toward benzene dihydrodiol and testosterone exhibited identical thermostability and susceptibility to inhibition by quercitrin, SH-reagents, nonsteroidal estrogens and anti-inflammatory agents. On the other hand, the minor form of the enzyme, which oxidized benzene dihydrodiol but not 17 beta-hydroxysteroids, also reduced various aldehydes well and was specifically inhibited by barbiturates and sorbinil. These results indicate that the major form of dihydrodiol dehydrogenase is identical to 17 beta-hydroxysteroid dehydrogenase and the minor enzyme form to aldehyde reductase.

Alcohol Dehydrogenase↗
PubMed1988

Supersensitivity of coronary arteries in variant angina to spasm induced by intracoronary acetylcholine.

Acetylcholine (20 to 100 micrograms) was infused directly into coronary arteries in 10 patients with variant angina (group A), 13 subjects without coronary artery disease (group B) and 8 patients with significant organic coronary artery stenosis (greater than or equal to 50%) but without variant angina (group C) during coronary arteriography, to clarify the action of this agent on coronary arteries. Temporary pacing was performed at a demand heart rate of 40 beats/min while bradyarrhythmia developed. Coronary arteriography after administration of acetylcholine showed coronary vasoconstriction in all 10 patients (100%) of group A. Angina accompanied by electrocardiographic ischemic changes in 9 of 10 (90%, 7 ST-segment elevation and 2 depression) was provoked during this test. In the patients of group B, acetylcholine also induced vasoconstriction in 8 of 22 (36%) coronary arterial systems examined, chest pain in 3 (14%) and ST-segment deviation in none (0%). In the patients of group C, acetylcholine induced vasoconstriction in 3 of 9 (33%), chest pain in 2 (22%) and ST-segment depression in 1 (11%). No definite coronary artery dilation induced by acetylcholine was noted. Coronary vasoconstriction (p less than 0.05), electrocardiographic ischemic findings (p less than 0.01) and chest pain (p less than 0.01) were induced significantly more frequently in group A than in both groups B and group C. No significant difference was found between group B and group C. The coronary arteries in the patients with variant angina seem to be more susceptible to acetylcholine than those of patients without variant angina irrespective of the presence of significant atherosclerosis.

Acetylcholine↗
PubMed1988

Purification and characterization of NADP+-dependent 3 alpha-hydroxysteroid dehydrogenase from mouse liver cytosol.

A monomeric 3 alpha-hydroxysteroid dehydrogenase with a molecular weight of 34,000 was purified to apparent homogeneity from mouse liver cytosol. The enzyme catalyzed the reversible oxidation of the 3 alpha-hydroxy group of C19-, C21-, and C24-steroids, reduced a variety of carbonyl compounds, and was inhibited by SH-reagents, synthetic estrogens, anti-inflammatory drugs, prostaglandins, and delta 4-3-ketosteroids. Although these properties are similar to those of the enzyme from rat liver cytosol, the mouse enzyme exhibited low dehydrogenase activity toward benzene dihydrodiol and some alicyclic alcohols, it showed a strict cofactor specificity for NADP(H), and high substrate inhibition was observed in the reverse reaction. In addition, dexamethasone, deoxycorticosterone, and medroxyprogesterone acetate inhibited the mouse enzyme competitively at low concentrations and noncompetitively at high concentrations, whereas hexestrol, indomethacin, and prostaglandin A1 were competitive inhibitors. Steady-state kinetic measurements in both directions indicated that the reaction proceeds through an ordered bi bi mechanism with the cofactors binding to the free enzyme. The 3-ketosteroid substrates inhibited the enzyme uncompetitively at elevated concentrations, suggesting that the substrates bind to the enzyme.NADPH complex and to the enzyme NADP+ complex.

3-Hydroxysteroid Dehydrogenases↗
PubMed1988

Molecular interaction of bovine kininogen and its derivatives with papain.

The molecular interaction of bovine kininogen and its derivatives with papain was investigated. High-molecular-weight kininogen (HMWK) or low-molecular-weight kininogen (LMWK) and inactive papain treated with N-[N-(L-3-trans-carboxyoxiran-2-carbonyl)-L-leucyl]agmatine (E-64) formed, respectively, a complex, which was dissociable on sodium dodecyl sulfate polyacrylamide-gel electrophoresis (SDS-PAGE). The densitometric determination of the bands separated on SDS-PAGE and amino acid analysis of the samples extracted from the electrophoresis gel revealed that the complex between kininogen and papain is formed in a molar ratio of one to one. Moreover, analysis of the inhibition of the caseinolytic activity of papain by these kininogens indicated that HMWK, LMWK, and kinin-free derivatives obtained from both kininogens inhibit active papain with a stoichiometry of 1:1. On the other hand, the papain activity was inhibited by two kinds of cyanogen bromide fragments isolated from the heavy chain of HMWK. These two fragments with Ki values of 38 and 0.64 nM corresponded, respectively, to residue Nos. 47 to 243 and Nos. 244-360 of the HMWK heavy chain. These results suggest that in the intact HMWK and LMWK, one of the two potential reactive sites interacts with papain to form a complex and that the other reactive site becomes active only after separation of the two sites.

Amino Acids↗
PubMed1988

Chemical study of the mechanism for conversion of dimethylacetal obtained by methanolysis of plasmalogen to alkenylmethylether.

The mechanism for the conversion of dimethylacetal which was obtained by methanolysis of plasmalogen to alkenylmethylether was studied by IR spectroscopy, TLC, GC-MS, 1H-NMR, and 13C-NMR. Heating dimethylacetal in an evacuated sealed glass tube at 250 degrees C for 15 min quantitatively yielded the corresponding alkenylmethylether. The alkenylmethylether yielded two bands of about equal amounts on TLC due to cis and trans configurations at the C-1 and C-2 position. Both 1H-NMR and 13C-NMR showed that the signals of protons and carbons at O-CH3, C-1, and C-2 positions were shifted downfield due to the formation of a double bond between the C-1 and C-2, and that each signal derived from O-CH3, C-1, or C-2 position was divided into two signals due to the formation of cis and trans isomers of the alkenylmethylether. As the two signals had the same intensities, it was suggested that equivalent amounts of cis and trans isomers of the alkenylmether were formed. Since alkenylmethylether was quantitatively converted from dimethylacetal, it was suggested that the alkenylether of plasmalogen could be analyzed as alkenylmethylether together with the fatty acid methylester at the same time by GLC using a silicone capillary column, OV-101.

Acetals↗