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Biomedical subjects

K Matsui

Publications and source records attributed to K Matsui.

At least 685 records · Page 38Linked to original sources
PubMed1982

Bentall's operation. A modification for coronary-graft anastomosis in an annuloaortic ectasia without displacement of the coronary origins.

Bentall's operation using a composite graft for complete replacement of an ascending aortic aneurysm and associated incompetent aortic valve is being widely used. In case of no displacement of the coronary origins, however, this technique often leads to difficulties in restoring the coronary flow. We now report a successful modification for this coronary-graft anastomosis.

Adolescent↗
PubMed1982

Coenzyme Q10: the prophylactic effect on low cardiac output following cardiac valve replacement.

A randomized, prospective study of the effectiveness of preoperative administration of coenzyme Q10 on the prophylaxis of postoperative low cardiac output state was performed in 50 patients with acquired valvular diseases necessitating valve replacement. There were 25 patients in the treatment group and 25 in the control group. Patients in the treatment group received 30 to 60 mg of coenzyme Q10 orally for six days before operation. Preoperative clinical variables, operative procedures, total cardiopulmonary bypass time, and aortic cross-clamping time were similar for the two groups. Postoperatively, mild to severe low cardiac output state developed in 28 of 50 patients (56%) and necessitated the administration of considerable amounts of inotropic agent. The treatment group showed a significantly lower incidence of low cardiac output state during the recovery period than the control group (p less than 0.05). These results suggest that preoperative administration of coenzyme Q10 will increase the tolerance of human hearts to ischemia during aortic cross-clamping.

Adult↗
PubMed1982

Thermodynamics of association of 8-substituted riboflavins with egg white riboflavin binding protein.

Association constants of 14 species of riboflavin derivatives with hen egg-white riboflavin binding protein were measured by a fluorometric titration method using flavin and protein fluorescence in a temperature range of 10--42 degrees C. The derivatives were riboflavins whose 8-CH3 group was substituted with alkylamino, alkyloxy, halogen or hydrogen. The flavin derivatives were classified into four groups, i.e., RR'N, HRN, RO, and halogen, on the basis of the linear relation between enthalpy and entropy changes (linear free energy relationship), and from the chemical structures of the 8-substituents. The relation between the entropy change and the bulkiness of 8-substituents suggested burying of the substituents in a cavity of the protein, and provided an indication of the size of the substituent-accepting cavity. The relation also suggested an electric repulsion between halogen substituents and the binding site. A very good correlation was found between the constant term of the linear free energy relation and the wavelength of the visible absorption peak of flavins, and this correlation suggested the electronic nature of the flavin-protein interaction.

Carrier Proteins↗
PubMed1982

Thermodynamics of association of egg yolk riboflavin binding protein with 8-substituted riboflavins. Comparison with the egg white protein.

The association constants of hen egg yolk riboflavin binding protein with 8-substituted riboflavins were measured using a fluorometric titration method in the range of 10-40 degrees C, and thermodynamic parameters were calculated using ordinary methods. The flavins used were riboflavins whose 8-methyl group was substituted with HRN, RR'N, RO type groups, or halogen atoms. From a plot of delta H degrees against delta Su (unitary entropy change), the flavins were classified into four groups, i.e., HRN, RR'N, RO, and halogen type substituents. In each group, the linear free energy relationship, delta H degrees = u . delta Su+v (u and v were constants specific for each group), was found to be similar to that for egg white riboflavin binding protein, though with different specific constants for each egg protein. The relation between delta Su and the bulkiness (molecular volume) of 8-substituents suggested burying of the 8-substituents in a cavity of the protein similar to that of the egg white protein, but of smaller volume. The behavior of the halogen group was similar to that of the other three groups, and could be explained in terms of the bulkiness of the substituents rather than by assuming electric repulsion between halogen substituents and the binding site, which is in contrast with the case of egg white protein. A linear relation between v value and the wavelength of the visible absorption peak of flavins wa also found.

Animals↗
PubMed1982

Methyl hydroperoxy-epoxy-octadecenoate as an autoxidation product of methyl linoleate: a new inhibitor-uncoupler of mitochondrial respiration.

A new peroxide compound (ML-X) was isolated from an autoxidation product of methyl linoleate and was determined as methyl 9-hydroperoxy-12, 13-epoxy-10-octadecenoate. This compound inhibited state 3 respiration of rat heart- and liver mitochondria when glutamate and malate were used as substrates, but not when the substrate was succinate. State 4 respiration of mitochondria was not affected when glutamate-malate was used as the substrate, but it was stimulated when the substrate was succinate. ML-X inhibited oxidative phosphorylation of the mitochondria and abolished the membrane potential formed by respiration or by added ATP. NADH oxidase activity of submitochondrial particles was inhibited by ML-X but succinate oxidase activity was not inhibited. NADH-acceptor reductase activities of submitochondrial particles were inhibited by ML-X to the same extents as by rotenone. These findings show that ML-X has dual effects on mitochondrial respiration as (1) an inhibitor of NADH dehydrogenase complex and (2) an uncoupler. Neither methyl linoleate monohydroperoxide nor methyl epoxy stearate has such effects. ML-X is a new type of inhibitor-uncoupler of mitochondrial respiration in which hydroperoxy- and epoxy groups co-operate.

Animals↗
PubMed1982

Dermatofibrosarcoma protuberans and its tissue culture study -- ultrastructural, enzyme histochemical and immunological study.

Dermatofibrosarcoma protuberans arizing in the thigh of a 23-year-old female is reported with an investigation of tumor cell character by electron microscopy, enzyme histochemistry, immunological and in vitro tissue culture techniques. The tumor tissue showed histologically a peculiar storiform arrangement of plump spindle cells with dense proliferation. Electron microscope revealed histiocytic cell structures of some tumor cells: lysosomes, phagosomes, and sparse rough endoplasmic reticula. They revealed diffuse positive reactions to acid phosphatase (Ac Pase) and non-specific esterase. Short-time culture of the tumor tissue indicated rather round and polygonal cells admixed with spindle cells, positive to Ac Pase and non-specific esterase with diffuse reaction. Most of the round cells possessed Fc and C3 receptors on their surface and phagocytic activity. Dermatofibrosarcoma protuberans is probably a histiocytic tumor and structural characteristics of schwann cells were not recognized.

Adult↗
PubMed1982

A tumor composed of myofibroblasts: an ultrastructural study.

A subcutaneous tumor of the right temporal region of head was removed from an 8-year-old boy. This tumor was studied by light and electron microscopy. He was found to have had a retroperitoneal inflammatory fibrous histiocytoma which had been excised seven years ago. The subcutaneous tumor histologically consisted of spindle cells in fascicles, which did not arrange in a storiform or herring-bone pattern. Electron microscopically, this tumor was chiefly composed od myofibroblasts. electron microscopy is essential to determine the cell types of a tumor and we have classified this tumor as a tumor of myofibroblasts. The relationship between the retroperitoneal tumor and the head tumor was discussed.

Brain Neoplasms↗
PubMed1982

Purification and characterization of a Ca2+- and calmodulin-dependent protein kinase from rat brain.

A Ca2+- and calmodulin-dependent protein kinase was purified from rat brain cytosol fraction to apparent homogeneity at approximately 800-fold and with a 5% yield. The purified enzyme had a molecular weight of 640,000 as determined by gel filtration analysis on Sephacryl S-300 and a sedimentation coefficient of 15.3 S by sucrose density gradient centrifugation, and resulted in a single protein band of MW 49,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These results suggest that the native enzyme has a large molecular weight and consists of 11 to 14 identical subunits. The purified enzyme exhibited Km values of 109 and 30 microM for ATP and chicken gizzard myosin light chain, respectively, and Ka values of 12 nM and 1.9 microM for brain calmodulin and Ca2+, respectively. In addition to myosin light chain, myelin basic protein, casein, arginine-rich histone, microtubule protein, and synaptosomal proteins were phosphorylated by the enzyme in a CA2+- and calmodulin-dependent manner. The purified enzyme was phosphorylated without the addition of the catalytic subunits of cyclic AMP-dependent protein kinase. Our findings indicate that there is a multifunctional Ca2+- and calmodulin-dependent protein kinase in the brain and that this enzyme may regulate the reactions of various endogenous proteins.

Animals↗
PubMed1982

Dissociation of alterations in levels of myosin light chain kinase and cyclic AMP-dependent protein kinase in rabbit myometrium during pregnancy.

The alteration in levels of myosin light chain kinase and cyclic AMP-dependent protein kinase was studied in rabbit myometrium during pregnancy. The specific activity of myosin light chain kinase was 160.9 +/- 2.7, 128.1 +/- 3.5, and 126.5 +/- 4.4% at the 10th, 20th and 28th days after pregnancy, respectively, in comparison with the value seen in samples from non-pregnant rabbits. On the other hand, the specific activity of cyclic AMP-dependent protein kinase gradually decreased to 75.9 +/- 1.7, 58.7 +/- 3.5 and 36.9 +/- 1.9% of that of the control at each time with the increase in the time of gestation. The protein kinase inhibitor was not involved in the decrease in cyclic AMP-dependent protein kinase. These results suggest that the dissociation of the dynamic states of the two enzymes may make it possible for the myometrium to efficiently respond to contraction in the last stage of pregnancy.

Animals↗
PubMed1982

Coronary arterial involvement in Takayasu's disease.

This report describes the findings in a young woman with Takayasu's disease, resulting in angina pectoris due to severe narrowing of the left coronary ostium. The patient underwent aortocoronary bypass surgery. The disappearance of angina, with reversal of positive findings on the treadmill exercise test, was noted postoperatively. Selective coronary angiography should be performed in patients with Takayasu's disease with a positive exercise test and symptoms of chest pain.

Adolescent↗
PubMed1982

Pregnancy following combined therapy with thyroid hormone and bromocriptine in a patient with amenorrhea-galactorrhea due to primary hypothyroidism.

Combined therapy with thyroid hormone (desiccated thyroid) and bromocriptine (CB-154) was applied in a 29-year-old patient with amenorrhea-galactorrhea due to primary hypothyroidism. Two months after commencing administration of desiccated thyroid, the elevated serum level of TSH returned to the normal range while that of PRL remained within the supranormal range (from 134 ng/ml to 86.7 ng/ml). However, it fell to the normal range 2 weeks after administration of CB-154 with thyroid hormone. Subsequently, the galactorrhea completely ceased and ovulatory menstruation resumed with 3 months, and conception was achieved directly after that menstrual period. Only desiccated thyroid was administered during pregnancy and the patient delivered a male infant weighing 2,800 g without difficulty.

Adult↗
PubMed1982

[Combination chemotherapy with peplomycin and carboquone (esquinon) for squamous cell carcinoma of the lung].

Eighteen previously untreated patients with squamous cell carcinoma of the lung were treated with a combination of a new bleomycin derivative, peplomycin and esquinon (PQ). One patient achieved a complete response (5.5%) and 5 patients a partial response (27.8%). Overall response rate was 33.3%. Median survival time of 6 patients with complete and partial response was 54 weeks and that of 12 patients with no change and progressive disease was 15 weeks. Toxicities included nausea and/or vomiting in 89%, fever in 61%, interstitial pneumonitis in 28% and leukopenia in 17%. PQ regimen appears to be effective in the treatment of squamous cell carcinoma of the lung.

Aged↗