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Biomedical subjects

Y Tamura

Publications and source records attributed to Y Tamura.

At least 559 records · Page 31Linked to original sources
PubMed1988

Role of the renal nerve in glucocorticoid hypertension.

The present study was designed to investigate the involvement of the renal nerve in glucocorticoid hypertension and to assess the role of the renin-angiotensin system in dexamethasone-induced hypertension. The elevated blood pressure in dexamethasone treated rats showing a significant increase in plasma renin concentration (PRC) and activity (PRA) was attenuated dose-dependently by the angiotensin I converting enzyme (ACE) inhibition. Bilateral renal denervation caused a partial decrease in the elevated blood pressure, abolished the increased PRC and PRA, and reduced the dose-dependent decrease in blood pressure with ACE inhibition in dexamethasone treated rats. Although the reduction in body weight and increases in urine volume, urinary sodium excretion and hematocrit were clearly seen following dexamethasone administration, dexamethasone-treated renal denervated rats showed the same degree of change in any of the variables as dexamethasone-treated sham-operated rats. Thus, our results indicate that the stimulation of the renin-angiotensin system through the activation of the renal nerve may be partially responsible for the dexamethasone-induced high blood pressure and, therefore, bilateral renal denervation reduces, partially but significantly, the elevated blood pressure, suggesting that the attenuation of oversecretion of renin contributes to the lowering of the blood pressure.

Animals↗
PubMed1988

[Controlled study of MQF-OK therapy with FT and with UFT on various advanced gastrointestinal cancers. Hirosaki Cooperative Study Group of Cancer Chemotherapy].

Our cooperative study group carried out a controlled study of MQF-OK therapy with tegafur (FT) (group A) and with UFT (group B), a compound of FT and uracil in the molar ratio of 1:4, on various advanced gastrointestinal cancers. From January 1985 to May 1987, 91 patients were entered into this study, and 11 cases were ineligible for the protocol (11%). Fifty of 80 cases had advanced gastric cancer, 30 had pancreatic cancer or other cancers, such as colon cancer, and biliary tract cancer. They were divided into group A or B at random. There was no difference in the patient characteristics between group A and B. In gastric cancer, 23 of 50 cases were randomized into group A and 27 cases into group B. Two cases in group A (8.7%) and 7 cases in group B (25.9%) showed PR. The response rate of group B was better than that of group A, but the value of P by Kruskal-Wallis test was 0.27. Thirteen of the 30 other cancers were randomized into group A and 17 cases into group B. Three cases in group A and B, respectively, showed PR. There was no significant difference between the two groups in terms of antitumor effect, prolongation of life or side effects. In conclusion, it was suggested that the MQF-OK therapy with UFT was beneficial for the Remission Induction Therapy in advanced gastric cancer.

Adult↗
PubMed1988

[MQF-FT and MQF-UFT in gallbladder and bile duct cancer].

Four patients with gallbladder cancer and two with bile duct cancer were treated with mitomycin C, carboquone, 5-fluorouracil and OK-432 (MQF-OK therapy) plus tegafur (FT) or UFT. MQF-OK therapy was administered according to our original method. FT and UFT were orally given in a dose of 600-800 mg/body/day and 300-400 mg/body/day, respectively. Three with gallbladder cancer and one with bile duct cancer showed PR. Myelosuppression was observed in all cases, but recovered in two weeks after MQF therapy. We recommend the further trial of MQF-OK therapy plus FT or UFT for gallbladder and bile duct cancer.

Administration, Oral↗
PubMed1988

Sarcomere length dependence of muscle stiffness changes during contraction recorded using ultrasonic waves.

We have developed a technique with which muscle stiffness changes during isometric contraction can be continuously recorded by measuring the propagation velocity of ultrasonic waves with negligibly small perturbations to the contractile system, and obtained an unexpected result that, during isometric contraction, muscle stiffness decreased in the transverse direction while it increased in the longitudinal direction. In the present study, we measured the stiffness of frog skeletal muscle with ultrasonic waves at various sarcomere lengths from 2.2 to more than 3.6 microns, and found that (1) the resting muscle stiffness is insensitive to the resting force development in both the longitudinal and the transverse directions, and (2) the absolute amount of both the longitudinal and the transverse stiffness changes during isometric tetanus decreased linearly with increasing sarcomere length, approaching zero at 3.6-3.8 microns sarcomere lengths. These results indicate that the stiffness changes measured with ultrasonic waves reflect the changes in the number of cross-links between the myofilaments.

Animals↗
PubMed1987

Transformation of 15-hydroperoxyeicosapentaenoic acid to lipoxin A5 and B5, mono- and dihydroxyeicosapentaenoic acids by porcine leukocytes.

15-Hydroperoxy[1-14C]eicosapentaenoic acid derived from eicosapentaenoic acid (EPA) was incubated with suspensions of porcine leukocytes. Incubation with porcine leukocytes resulted in the formation of seven dihydroxy compounds, one monohydroxy and one hydroxyepoxy compound. After separation by reverse-phase and straight-phase HPLC, GC/MS analysis revealed that these metabolites were four isomers of 8,15-diHEPEs, two isomers of 14,15-diHEPEs, one isomer of 5,15-diHEPE, 15-HEPE and an epoxyalcohol: 13-hydroxy-14,15-epoxyeicosatetraenoic acid. In addition to the above metabolites, two trihydroxytetraene derivatives were also isolated. GC/MS and ultraviolet spectroscopy identified the two trihydroxypentaene derivatives as 5,6,15-trihydroxy-7,9,11,13,17-eicosapentaenoic acid (lipoxin A5) and 5,14,15-trihydroxy-6,8,10,12,17-eicosapentaenoic acid (lipoxin B5). This study demonstrated that the 15-hydroperoxide of EPA can be actively converted to various hydroxylated products via the 5-, 12- and 15-lipoxygenase as well as epoxyisomerase pathways in the porcine leukocytes.

Animals↗
PubMed1987

Effect of cyclophosphamide and carrageenan on resistance of mice to Erysipelothrix rhusiopathiae.

The immunosuppressive effect of cyclophosphamide (CY) or carrageenan (CG) treatment was investigated to clarify the mechanism of resistance of mice to Erysipelothrix rhusiopathiae infection. In mice inoculated with attenuated E. rhusiopathiae, death occurred and bacterial growth in the spleen was enhanced only by CY treatment; in CG-treated mice, no death occurred and bacterial growth in the spleen was kept at a low level for at least 23 days, similar to that of nontreated control mice. These results indicated that polymorphonuclear leucocytes rather than macrophages may play an important role in the resistance of mice to E. rhusiopathiae infection.

Animals↗
PubMed1987

Opsonic activity of anti-flagellar serum against Clostridium chauvoei by mouse polymorphonuclear leucocytes.

The role of anti-flagellar serum against Clostridium chauvoei in phagocytosis by mouse polymorphonuclear leucocytes was examined. Anti-flagellar serum markedly increased phagocytic rate against the flagellated strain Okinawa but not against a non-flagellated mutant (NFM) derived from the same strain, while anti-NFM serum increased the phagocytic rate against both strains. These results indicate that anti-flagellar serum exerts its protective effect by opsonic activity.

Agglutination Tests↗
PubMed1987

Antiserum against culture filtrate is cross-protective for various serovars of Erysipelothrix rhusiopathiae.

The protective effect of porcine antiserum prepared against culture filtrate (CF) of an attenuated strain of Erysipelothrix rhusiopathiae (serovar 2) in mice to challenge with 20 virulent strains of 18 serovars and one type N was investigated. Passively immunized mice survived after challenge with serovars 1a, 1b, 2, 5, 6, 8 (strain Goda), 11, 12, 15, 16, 21 or type N, but 10-30% mortality occurred in immunized mice challenged with each strain of serovars 4, 7, 8 (strain 911), 9, 18 or 19 and 70% mortality to serovar 10 (strain 2179). All immunized mice died after challenge with serovar 20 (strain 2553). Non-treated control mice died after challenge with all serovars and the type tested.

Agglutination Tests↗
PubMed1987

Correlation between adherence of Erysipelothrix rhusiopathiae strains of serovar 1a to tissue culture cells originated from porcine kidney and their pathogenicity in mice and swine.

Adherence of four virulent and four avirulent strains of Erysipelothrix rhusiopathiae, serovar 1a, to porcine kidney cell lines, PK-15 and ESK cells, was examined in an in vitro system. The virulent strains adhered well to the cells (range of means, 9.95 +/- 0.87-36.01 +/- 1.10 per cell). In contrast, the avirulent strains showed negligible adherence to the cells (range of means, 0.11 +/- 0.04-1.41 +/- 0.13 per cell). Pretreatment of bacteria with heat, trypsin, or antiserum resulted in a marked decrease in adherence. Scanning electron microscopic examination revealed that the bacteria attached directly to the microvilli of cells.

Animals↗
PubMed1987

Production, characterization, and protective effect of monoclonal antibodies to Clostridium chauvoei flagella.

Monoclonal antibodies to flagella of Clostridium chauvoei were obtained by the fusion of murine myeloma cells (P3-X63-Ag8-U1) and spleen cells from BALB/c mice immunized with partially purified flagella of strain Okinawa. Enzyme-linked immunosorbent assay and Western blot analysis with partially purified flagella, flagellated cells, and nonflagellated mutants were used to show that five monoclonal antibodies are specific for the flagella. In the Western blot analysis, all five antiflagellar antibodies reacted strongly with the 56,000-molecular-weight protein, which corresponds to the flagellin. By using the ELISA-derived reactivity of monoclonal antibodies to the various clostridia and the competitive binding assay, we showed that the flagella of C. chauvoei had at least three epitopes. The three antiflagellar monoclonal antibodies (one immunoglobulin G and two immunoglobulin M) demonstrated passive protective effects in mice. These results strongly suggest that the flagella of C. chauvoei are important for protective immunity in mice.

Animals↗