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Biomedical subjects

H Masuda

Publications and source records attributed to H Masuda.

At least 505 records · Page 28Linked to original sources
PubMed1987

The effects of prostaglandin E1 on the pepsin activities in gastric mucosa and juice.

Prostaglandin E1 elevated pepsin activity in gastric mucosa but lowered pepsin activity in the gastric juice of rats treated by pylorus ligation and intragastric administration of hydrochloric acid. In these animals zymogen granules with low electron density were numerous in the gastric chief cells following prostaglandin E1 treatment. The prostaglandin E1-induced increase in mucosal pepsin activity was slightly inhibited by actinomycin D and there was no apparent increase in 3H-thymidine incorporation into gastric mucosa following treatment with prostaglandin E1. It is suggested that prostaglandin E1 causes an elevation of pepsin activity in the gastric mucosa by stimulating pepsin synthesis and perhaps also by facilitating pepsin release from zymogen granules. However, it also appears to inhibit pepsin release from the mucosa into the gastric cavity judging by the decrease of pepsin activity in gastric juice. The reduced pepsin activity in gastric juice may account, in part, for the reported anti-ulcerative action of prostaglandin.

Animals↗
PubMed1987

[Clinical trials of flomoxef in complicated urinary tract infections].

Flomoxef (6315-S, FMOX), a new oxacephem antibiotic was studied clinically in 27 patients with complicated urinary tract infections. FMOX was intravenously administered at a dose of 1.0 g twice daily for 5 days. Clinical effect of FMOX on patients with complicated urinary tract infections were excellent in 11.5%, moderate in 57.7% and overall clinical efficacy rate was 69.2%. During the treatment with FMOX, urticaria was observed in 1 case. In laboratory tests, a decrease of RBC, Hb and Ht in 1 case, a decrease of WBC in 1 case and an elevation of GPT in another case were observed. But these abnormal values were slight and transient.

Adult↗
PubMed1987

Membranous lipodystrophy. Light and electron microscopic study of a biopsy case.

Membranous lipodystrophy is a peculiar systemic disease almost exclusively found in Japan and Scandinavia and characterized by formation of numerous membranous structures in the adipose tissue of bone marrow and soft tissue. Light and electron microscopic study of a biopsy case of the disease was presented. The membranous structures consisted of membrane and inner space on both light and electron microscopic study. The membrane consisted of two kinds of layers, dense and amorphous. The dense layer was positive for lipid stainings. The amorphous layer did not show any definite lipid constituents and was supposed to consist of an amorphous substance derived from abnormal fat metabolism of diseased fat cells, degenerative cytoplasms of the diseased cells, and/or stromal cells. It probably also had some stromal substance alteration due to membranolipodystrophic change. Accumulation of the amorphous layer in the interstitium leads to degeneration and disappearance of adjacent fat cells. This process may play a role in further advance of membranous structures.

Adipose Tissue↗
PubMed1987

[Tissue concentration of (2"R)-4'-O-tetrahydropyranyladriamycin in renal cell carcinoma and urinary bladder tumor (second report)].

Twenty milligrams of (2"R)-4'-O-tetrahydropyranyladriamycin (THP) was administered intravenously to 14 patients with renal cell carcinoma and 11 with urinary bladder tumor at the start of surgery. Heparinized peripheral blood samples were collected at regular intervals and separated into plasma and blood cell fractions by centrifugation for the estimation of the THP concentration. The THP concentrations in the surgical specimens were also studied. In the tissue of renal cell carcinoma, the nuclear fraction was obtained by fractionation in order to estimate the THP concentration. The THP concentrations of the plasma and blood cell fractions in both renal cell carcinoma and urinary bladder tumor gradually decreased with the lapse of time after administration. In renal cell carcinoma, grade 3 tumors revealed lower tissue and nuclear concentrations of THP than those of grade 1 and 2 tumors. Likewise, the tissue and nuclear concentrations of high-stage tumors were lower than those of low-stage tumors. On the other hand, in urinary bladder tumors, the THP concentrations in the tumors were found to be higher than those in normal urinary mucosa and muscle.

Carcinoma, Renal Cell↗
PubMed1987

Specificity of proto-oncogene amplification in human malignant diseases.

DNAs from 253 fresh human tumors of 38 different types were hybridized with 17 different oncogene probes. The analysis demonstrated unique associations between amplification of specific oncogenes and specific types of tumors. In a large number of cases it was determined that amplified oncogenes occurred in 10 to 20% of tumors with the following specific associations: c-myc in adenocarcinomas, squamous carcinomas and sarcomas but not hematologic malignancies; c-erbB2 in adenocarcinomas, particularly breast cancers; c-erbB1 in squamous carcinomas; N-myc in neuroblastomas. A small number of cases suggested other specific associations: amplified c-myb in breast cancers; amplified c-ras-Ha and c-ras-Ki in ovarian carcinomas. In addition, there was a correlation between amplification of c-myc and the clinical stage of adenocarcinomas, and amplification of c-erbB2 and the clinical stage and lymph node involvement of breast cancers.

Carcinoma↗
PubMed1987

[Comparison between the succinate dehydrogenase inhibition test and ATP assay for in vitro chemosensitivity testing].

The predicted level of cell viability was compared between the succinate dehydrogenase inhibition (SDI) test and the adenosine triphosphate (ATP) assay, both of which are used for in vitro human tumor chemosensitivity testing. After HeLa cells had been exposed to various concentrations of 5-FU for 1, 2, 3 or 4 days, the decrease occurring in viable cell number correlated with that of succinate dehydrogenase (EC 1.3.99.1) activity and that of the intracellular ATP level of the viable cells. In dead cells, the ATP level was extensively decreased, but the succinate dehydrogenase activity remained at a level of 11% of that of 5-FU-untreated viable cells, even on day 4. The cell viability correlated well with the intracellular ATP level, as compared with the succinate dehydrogenase activity. The activity remaining in dead cells must thus be taken into consideration for the prediction of chemosensitivity in the SDI test, but not in the ATP assay.

Adenosine Triphosphate↗
PubMed1986

CS-514, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase: tissue-selective inhibition of sterol synthesis and hypolipidemic effect on various animal species.

CS-514 is a tissue-selective inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, a key enzyme in cholesterol synthesis. For the microsomal enzyme from rat liver, the mode of inhibition is competitive with respect to hydroxymethylglutaryl-CoA, and the Ki value is 2.3 X 10(-9) M. CS-514 also strongly inhibited the sterol synthesis from [14C]acetate in cell-free enzyme systems from rat liver and in freshly isolated rat hepatocytes; the concentrations required for 50% inhibition were 0.8 ng/ml and 2.2 ng/ml, respectively. On the other hand, the inhibition by CS-514 was much less in the cells from nonhepatic tissues such as freshly isolated rat spleen cells, and cultured mouse L cells and human skin fibroblasts. In addition, the cellular uptake of 14C-labeled CS-514 by isolated rat spleen cells or mouse L cells was less than one-tenth of that by isolated hepatocytes. These differences between hepatic and nonhepatic cells were further confirmed by the fact that CS-514 orally administered to rats inhibited sterol synthesis selectively in liver and intestine, the major sites of cholesterogenesis. CS-514 markedly reduced serum cholesterol levels in dogs, monkeys and rabbits, including Watanabe heritable hyperlipidemic (WHHL) rabbits, an animal model for familial hypercholesterolemia in man, but did not reduce those in rats and mice. In the former case, preferential lowering of atherogenic lipoproteins was observed in all of the animals tested. The biliary neutral sterols significantly decreased, whereas the amount of biliary bile acids was not affected by administration of the drug to dogs.

Animals↗
PubMed1986

Increased release of atrial natriuretic polypeptides in rats with DOCA-salt hypertension.

This study compared atrial and plasma concentrations of immunoreactive alpha-rat atrial natriuretic polypeptide (i alpha-rANP) in rats given tap water (control), a 1% saline solution (salt), deoxycorticosterone acetate (DOCA) and DOCA plus 1% saline solution (DOCA-salt) after 1 and 8 weeks of treatment. DOCA (100 mg/kg) was given by implanting a piece of silicon rubber impregnated with DOCA subcutaneously. Atrial i alpha-rANP increased, while plasma i alpha-rANP decreased with time in all groups. Atrial concentration of i alpha-rANP was significantly lower in the DOCA-salt group than in the other groups at 1 week, and was reduced in the DOCA and DOCA-salt groups as compared to the control group at 8 weeks. On the other hand, plasma concentration of i alpha-rANP was significantly higher in the DOCA and the DOCA-salt groups than in the control group at 1 week; the DOCA and DOCA-salt group values were also higher than the control and salt group values at 8 weeks. Atrial concentration of i alpha-rANP was inversely correlated with systolic blood pressure in the all rats at 1 week (r = 0.48, p less than 0.001) and at 8 weeks (r = 0.33, p less than 0.05). Plasma concentration of i alpha-rANP was positively correlated with systolic blood pressure at 8 weeks (r = 0.37, p less than 0.05). In addition, there was a significant positive correlation between plasma/atrial ratio of i alpha-rANP concentration and systolic blood pressure at either stage (r = 0.41, p less than 0.01 at 1 week; r = 0.40, p less than 0.01 at 8 weeks). Thus, it seems likely that the release of ANPs is increased in response to expansion of extracellular fluid volume or elevation of blood pressure, modifying the development of hypertension in DOCA-salt rats.

Animals↗
PubMed1986

Characterization of intermediate filaments and their structural organization during epithelium formation in pigmented epithelial cells of the retina in vitro.

Retinal pigmented epithelial cells of chicken have circumferential microfilament bundles (CMBs) at the zonula adherens region. Isolated CMBs are polygons filled with a meshwork composed primarily of intermediate filaments; they show three major components of 200 000, 55 000, and 42 000 daltons in SDS-gel electrophoresis. Here we have characterized the 55 000-dalton protein immunochemically and ultrastructurally. Immunoblotting and immunofluorescence microscopy have shown that the 55 000-dalton protein is an intermediate filament protein, vimentin. Vimentin filaments changed their distribution during differentiation of pigmented epithelial cells in culture. The protein in the elongated cells showed a fibroblast-type pattern of intermediate filaments. During epithelium formation, the filaments were uniformly distributed and formed a finer meshwork at the apical level. In pigmented epithelial cells that differentiated and matured in culture, vimentin and actin exhibited their characteristic behavior after treatment with colcemid. In the central to basal region of the cell, intermediate filaments formed thick perinuclear bundles. In the apical region, however, intermediate filaments changed in organization from a nonpolarized meshwork to a polarized bundle-like structure. Simultaneously, new actin bundles were formed, running parallel to the intermediate filaments. This suggests that there is some interaction between microfilaments and intermediate filaments in the apical region of these cells.

Actin Cytoskeleton↗
PubMed1986

Torsion of the gallbladder.

A 77-year-old Japanese woman with torsion of the gallbladder was surgically treated. Perhaps because of its rarity, the diagnosis is seldom made clinically, the condition generally being recognized only at laparotomy. Discussed herein are the possibility of preoperative diagnosis of this condition and the usefulness of ultrasonotomography.

Aged↗
PubMed1986

Structural similarities between kinocilium of vestibular hair cell and tracheal motile cilium in the guinea pig.

A rapid-freeze, deep-etch method was used to visualize the membrane characteristics as well as the three-dimensional ultrastructural features of a kinocilium of the guinea pig vestibular hair cell. A kinocilium of the vestibular hair cell had a typical ciliary necklace, consisting of six to seven parallel intramembrane particle arrays. The basal body of a kinocilium had a plate-structure called a terminal plate, in its interior. In the shaft region of a kinocilium, peripheral microtubules were connected to the central microtubules by periodic tiny linkers, called radial spokes. These structural features of a kinocilium were identical to those of the tracheal motile cilium.

Animals↗
PubMed1986

Advanced ovarian cancer treated by intraperitoneal immunotherapy with OK-432.

Twelve patients with advanced ovarian cancer with ascites were treated by intraperitoneal immunotherapy with OK-432 in combination with surgery and systemic immunochemotherapy. The median time for total resolution of ascites after the OK-432 injection was 7.1 days. In three of the four patients who died, it took more than the average number of days for the ascites to disappear. The ascites index, the ratio of the ascitic fluid volumes before and after intraperitoneal immunotherapy, was significantly higher in the patients who died than in those who survived. The side effects of intraperitoneal administration of OK-432 varied, but were not serious and relief was not needed in most cases. Intraperitoneal injection of OK-432 was considered effective in preventing the reappearance of ascites in these cases of advanced ovarian cancer, and the ascites index was believed to be related to the prognosis.

Adult↗