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Biomedical subjects

H Masuda

Publications and source records attributed to H Masuda.

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

[Clinical evaluation of surgical treatment of Graves' disease].

Five hundred and thirteen surgical patients with Graves' disease from 1970 to 1983 were subjected to this study. They were divided into three groups by period in which operation was performed; 1st period from 1970 to 1974, 2nd from 1975 to 1979, and 3rd from 1980 to 1983. Postoperative thyroid function was evaluated. The weight of remnant thyroid was the greatest in the first period and the smallest in the third. There were no differences of frequency of postoperative complications among these periods in spite of remarkable decrease of weight of remnant thyroid tissue in the third period. Remission of thyroid function, was most frequently observed in the group of the remnant thyroid weight from 4 to 8 grams. Recurrence of hyperthyroidism was frequently observed in the group of the greatest weight of remnant thyroid and hypothyroid state was frequently observed in the group of the smallest remnant thyroid. These results indicate that the remnant thyroid weight may be one of the most crucial factors which influence on the postoperative functional state of patients with Graves' disease, and remnant thyroid tissue weighing from 4 to 8 grams may be the most appropriate in subtotal thyroidectomy.

Evaluation Studies as Topic↗
PubMed1989

[A case of tubular adenoma of the breast preoperatively suspected to be an advanced cancer].

A very rare case of a tubular adenoma of the breast is reported. The patient, 59-year-old woman, was admitted to hospital because of a large, left breast tumor. The tumor, 11 cm in diameter, was adhered to the surface skin. Because a malignancy was suspected, an incisional biopsy was first carried out. A pathologic examination revealed it to be a tubular adenoma, and a simple mastectomy was chosen as the operative procedure because a latent malignancy was not ruled out. The removed tumor was grossly cystic and a histological examination supported the finding that it was a non-malignant tubular adenoma.

Adenoma↗
PubMed1988

Increased DNA repair as a mechanism of acquired resistance to cis-diamminedichloroplatinum (II) in human ovarian cancer cell lines.

A human ovarian cancer cell line, A2780, derived from an untreated ovarian cancer patient and relatively sensitive to cisplatin was treated by stepwise incubation with cisplatin to produce a cisplatin-resistant variant, 2780CP. The relative abilities of these cell lines to repair cisplatin-induced damage to cellular DNA then was examined by measure of [3H]thymidine incorporation into normal density DNA separated from bromodeoxyuridine-substituted DNA on alkaline cesium chloride gradients. These studies revealed that primary cisplatin resistance present in 2780CP was associated with a near twofold-increased ability to repair damage induced by the drug under conditions where 2780CP was approximately 5-fold resistant to cisplatin. Aphidicolin, a specific inhibitor of DNA polymerase alpha, showed a dose-dependent capacity to inhibit DNA repair in this system with maximum inhibition of 63% at 4 micrograms/ml. It was also found that inhibition of DNA repair during and shortly after cisplatin exposure resulted in an approximately threefold increase in the cytotoxicity of cisplatin as monitored by clonogenic cell survival in the resistant but not the sensitive parental cell line.

Aphidicolin↗
PubMed1988

An evaluation of the intraoperative staining technique using methylene blue for the detection of hyperplastic parathyroid glands.

Intraoperative staining with methylene blue was employed during parathyroid surgery on 50 glands from 13 patients, 5 with primary and 8 with secondary hyperparathyroidism. Forty-seven out of the 50 glands (94 per cent) were visualized by the staining and 2 out of the 13 patients were revealed to have supernumerary parathyroid glands. Since we started using this technique, there have been no cases of persistent hypercalcemia. The results of this study support the clinical usefulness of this staining procedure for detecting hyperplastic parathyroid glands in both primary and secondary hyperparathyroidism.

Diagnosis, Differential↗
PubMed1988

Sex ratio of early embryos fertilized in vitro with spermatozoa separated by percoll.

Early bovine embryos were obtained by in vitro fertilization and sexing carried out by chromosome analysis. Separation of bovine X- and Y-bearing spermatozoa was performed using Percoll density gradient centrifugation and the enrichment of X-sperm proportion was investigated. Through treatment with vinblastin sulfate and podophyllotoxin, 880 (48.6%) of 1812 embryos at two- to seven-cell stages at 48 to 53 h after sperm-egg incubation produced metaphase spreads, and 399 (45.3%) of these were successfully sexed; the sexable rate reaching 53.4% for four-cell embryos. Sexing rates for embryos from the original sperm of two bulls were 69.6% (32 46 ) in Bull A and 54.2% (58 107 ) in Bull B. Embryos fertilized in vitro with sperm sedimented at the bottom of sperm centrifuged under conditions (I) 50 to 85% of Percoll, 15 degrees C; (II) 30 to 80%, 10 degrees C; (III) 30 to 80% 20 degrees C; (IV) 30 to 90%, 20 degrees C, gave rise to male sex ratios of (I) 58.3% in Bull A and 53.5% in Bull B, (II) 65.9% in Bull A, (III) 49.3% in Bull B and (IV) 66.7% in Bull B. In conclusion, Percoll density gradient centrifugation under these four conditions was unsuccessful in separating X- and Y-bearing bull spermatozoa.

Journal Article↗
PubMed1988

A glycopeptide from adenocarcinoma tissue of human lung.

A glycopeptide from adenocarcinoma tissue of human lung was extracted by protein digestion with papain (EC 3.4.22.2) and trypsin (EC 3.4.21.4). This component was isolated by Pevikon block electrophoresis. It possessed hexose, glucosamine, fucose, galactosamine, and sialic acid. In its carbohydrate composition and also the abundance of threonin in the peptide moiety it was quite similar to the glycoprotein from gastrointestinal tract. The physical characteristic of the two, such as their optical rotation and viscosity, were also very similar each other.

Adenocarcinoma↗
PubMed1988

Comparison of glycopeptide in lung cancer tissues of different histological types.

The glycopeptide was studied in the pulmonary cancer tissues of three different histological types including squamous cell carcinoma, undifferentiated cell carcinoma, and adenocarcinoma. The glycopeptide preparation was made by digesting the lung cancer tissues with proteolytic enzymes followed by removal of enzymes and undigested protein. The comparison of the relative proportion of the glycopeptide, which migrated toward the anode slower than hyaluronic acid, and was stained with both alcian blue and PAS, and contained higher sialic acid, was carried out among three different histologic types of lung cancer. This glycopeptide was highest in adenocarcinoma, followed by undifferentiated cell carcinoma, and was lowest in squamous cell carcinoma.

Adenocarcinoma↗
PubMed1988

The mechanism of anaphase spindle elongation: uncoupling of tubulin incorporation and microtubule sliding during in vitro spindle reactivation.

To study tubulin polymerization and microtubule sliding during spindle elongation in vitro, we developed a method of uncoupling the two processes. When isolated diatom spindles were incubated with biotinylated tubulin (biot-tb) without ATP, biot-tb was incorporated into two regions flanking the zone of microtubule overlap, but the spindles did not elongate. After biot-tb was removed, spindle elongation was initiated by addition of ATP. The incorporated biot-tb was found in the midzone between the original half-spindles. The extent and rate of elongation were increased by preincubation in biot-tb. Serial section reconstruction of spindles elongating in tubulin and ATP showed that the average length of half-spindle microtubules increased due to growth of microtubules from the ends of native microtubules. The characteristic packing pattern between antiparallel microtubules was retained even in the "new" overlap region. Our results suggest that the forces required for spindle elongation are generated by enzymes in the overlap zone that mediate the sliding apart of antiparallel microtubules, and that tubulin polymerization does not contribute to force generation. Changes in the extent of microtubule overlap during spindle elongation were affected by tubulin and ATP concentration in the incubation medium. Spindles continued to elongate even after the overlap zone was composed entirely of newly polymerized microtubules, suggesting that the enzyme responsible for microtubule translocation either is bound to a matrix in the spindle midzone, or else can move on one microtubule toward the spindle midzone and push another microtubule of opposite polarity toward the pole.

Adenosine Triphosphate↗
PubMed1988

Tissue content of glycosaminoglycans in the diffuse idiopathic interstitial fibrosis patient.

Quantitative changes of glycosaminoglycans in lung tissues of patients with diffuse idiopathic interstitial fibrosis and patients with bronchial asthma were studied. The total amount of glycosaminoglycans in lung tissue of patients with diffuse idiopathic interstitial fibrosis increased in comparison to the lung tissue of those patients with bronchial asthma. The increase in tissue content of glycosaminoglycans was accompanied by an increase in dermatan sulfate level. The increases in total amount of glycosaminoglycans in relative proportion of dermatan sulfate were closely related to the clinical findings, including vital capacity of the lung, PaO2, serum lactate dehydrogenase, and to the pathologic pictures of the lung.

Aged↗
PubMed1988

Acid and alkaline invertases in suspension cultures of sugar beet cells.

Alkaline invertase was induced during the initiation of suspension cultures of single cells from leaf explants of sugar beets in Murashige-Skoog liquid medium which contained benzyladenine. This activity was barely detectable in the leaves themselves. In suspension cultures, the presence of both acid and alkaline invertases was detected; alkaline invertase was only present in the cytoplasm of the cultured cells, whereas acid invertase was present in the cytoplasm and cell walls, and was also detected in the culture medium. The cell wall contained at least three types of acid invertase; two of these activities were solubilized by saline (saline-released) and EDTA (EDTA-released), respectively, and the third remained tightly associated with the cell wall. Saline-released and EDTA-released invertases from the cell wall showed the significant differences in their properties: the saline-released enzyme had the highest affinity for sucrose among the invertases tested, and was easily bound to cell walls, to DNA, and to a cation exchanger, unlike the EDTA-released enzyme. Sucrose is the source of carbon for plant cells in suspension culture and is probably degraded in the cell wall by the saline-released invertase, which had the highest activity and the highest affinity for sucrose. Hexose products of this degradation would be transported to cytoplasm. Soluble invertase, EDTA-released invertase from the cell wall, and one of two extracellular invertases behaved similarly upon chromatography on DEAE-cellulose. They had similar activity profiles with changing pH, and similar K(m) values for sucrose. Thus it appears that they are identical. Two extracellular invertases found in the growth medium of the suspension cultures were probably identical with those in the soluble fraction of callus and seedlings of sugar beets, because they showed similar behaviors during chromatography on DEAE-cellulose, and had similar activity profiles with changing pH and K(m) values for sucrose.

Journal Article↗
PubMed1988

Purification and properties of glucoamylase from sugar beet cells in suspension culture.

Glucoamylase and alpha-amylase are present in callus and suspension cultures of sugar beets (Beta vulgaris L.) as well as in mature roots. The subcellular localization of glucoamylase differed in callus and suspension-cultured cells: in callus, glucoamylase was present together with alpha-amylase in the soluble fraction of cells, but in suspension cultures, it was present predominantly in the extracellular fraction while most of the alpha-amylase activity remained in cells. Glucoamylase activity was considerably lower in callus protoplasts relative to the activities of alpha-mannosidase and alpha-galactosidase and the suspension of callus in Murashige-Skoog liquid medium or in mannitol by brief agitation resulted in the release of glucoamylase to the medium. These findings suggest that glucoamylase in callus may be present in a soluble form in the free space in the cell wall. Both mature roots and callus contained alpha-amylase and glucoamylase in the soluble fraction. Glucoamylases in the soluble fraction of callus and in the medium of suspension cultures were purified separately to homogeneity by the same four-step purification procedure, which included fractionation with ammonium sulfate, column chromatography on carboxymethyl cellulose, gel filtration on Bio-Gel P-150, and preparative disc electrophoresis. The identity of the glucoamylases from the two sources was confirmed by a comparison of chromatographic behavior during purification, mobility during gel electrophoresis, M(r) (83,000 D by SDS PAGE), and enzymic and kinetic properties of the catalytic reaction, such as optimal pH and temperature, heat stability, and K(m) value for soluble starch. Glucoamylase from suspension cultures was one of the major proteins that were secreted into the medium. Dedifferentiation of leaves of young plants to callus was accompanied by induction of glucoamylase and repression of some alpha-amylases and the debranching enzyme.

Journal Article↗
PubMed1988

In-vitro fertilization of pig oocytes by frozen boar spermatozoa.

In Exp. 1 pig oocytes matured in vitro were used to evaluate the fertilizability in vitro of frozen epididymal (4 boars) and ejaculated (3 boars) spermatozoa that were preincubated in modified TCM-199 for 4 h at 37 degrees C. The percentages of penetrated oocytes with the frozen epididymal spermatozoa were 0-40%. In contrast, none of the oocytes were penetrated with the frozen ejaculated spermatozoa. In Exp. 2, oocytes matured in vivo were inseminated in vitro with the frozen epididymal spermatozoa that were known to penetrate oocytes matured in vitro. The penetration rate was 79% and the percentage of polyspermic oocytes was 57%. Culture for 30 h of oocytes matured in vivo and fertilized in vitro resulted in 51% (34/67) developing to the 2-cell stage. These embryos were transferred to 2 recipient gilts. One gilt became pregnant and a litter of 3 (1 live and 2 dead) was born. These results indicate that frozen epididymal spermatozoa can be used for in-vitro fertilization in the pig.

Animals↗
PubMed1988

Roles of fluid shear stress in physiological regulation of vascular structure and function.

The effects of fluid shear stress on the function and structure of the vascular system are outlined, based on the findings obtained in our laboratory or of our colleagues. First, it is pointed out that the adaptive response of the vascular wall to flow changes which we observed in the canine carotid artery shunted with the jugular vein altering the internal diameter to keep the wall shear stress constant, can attain the optimum vascular branching structure as predicted in the minimum work model by Murray. Electronmicroscopic studies of similarly shunted arteries revealing various morphological changes in the endothelial cells have suggested that the shear stress initially affects the endothelium. The in vitro experiments using cultured endothelial cells as well have exhibited that the mitotic activity of the cells significantly increases by applying fluid shear stress. From these findings, it is concluded that the adaptive response of the endothelium to the fluid shear stress is an inherent and key process locally regulating the vascular system to be in the most functional state.

Animals↗