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Biomedical subjects

H Nishida

Publications and source records attributed to H Nishida.

At least 343 records · Page 19Linked to original sources
PubMed1993

[Coronary artery bypass grafting with all arterial grafts using the internal thoracic, the gastroepiploic and the inferior epigastric arteries].

CABG with all arterial grafts using both the internal thoracic artery (RITA, LITA), the right gastroepiploic artery (GEA) and the inferior epigastric artery (IEA) was performed in 26 patients from July 1989 to August 1991. There were no early and late deaths. Early postoperative coronary angiography in all patients revealed that the best choice of anastomosis was RITA to LAD, LITA to LCX or DIA, and GEA to RCA (type A). All arterial grafts CABG is safe and feasible, but the saphenus vein graft must be used to avoid the anastomosis from small GEA to small LCX.

Abdominal Muscles↗
PubMed1993

[A right internal thoracic artery graft to the left anterior descending artery].

From 1987 to 1991, 48 patients received a right internal thoracic artery (RITA) to the left anterior descending artery (LAD). No operative death occurred, but two patients (4.2%) died during hospitalization due to graft versus host disease, and congestive heart failure. Graft patency of the RITA was 100%. After a 17.2 month mean follow-up, the 4 year actuarial survival rate (including all causes of death) was 85.3%, and the 4 year cumulative cardiac event free rate (including all cardiac deaths, myocardial infarction, reoperation, and PTCA) was 87.6%. The length of the RITA graft to the LAD, 15.6 +/- 1.1 cm, was significantly longer than that of the left internal thoracic artery (LITA) to the LAD, 12.9 +/- 1.1 cm. However, the flow of the RITA-LAD graft, 42.3 +/- 21.1 ml/min, was same as the flow of the LITA to the LAD, 42.1 +/- 19.6 ml/min. These findings justify wider use of the RITA to the LAD as a second arterial graft.

Adult↗
PubMed1992

[Prediction for effectiveness of steroid pulse therapy by MRI in Graves' ophthalmopathy].

Fifteen patients with Graves' ophthalmopathy (GO) were treated with intravenous methylprednisolone (steroid pulse therapy, 1g daily for 3 days a week, 2-4 times) and followed up by ophthalmological assessment and magnetic resonance imaging (MRI). The signal intensity of enlarged eye muscle and retrobulbar fat was examined with MRI at 0.5T with short inversion time inversion recovery (STIR) sequences. The signal intensity of eye muscle and retrobulbar fat tissue in STIR was evaluated as the ratio to cerebral substantia alba (signal intensity ratio). The thickness of enlarged eye muscle was measured by T1-weighted coronal images. The signal intensity ratios of enlarged eye muscle of GO patients were significantly higher than those of eight normal subjects. Although the signal intensity ratios of muscle and retrobulbar fat before therapy were not related to the severity of clinical findings of GO assessed by ophthalmopathy index, the initial signal intensity ratios of eye muscle and retrobulbar fat of ten patients with improved clinical findings of GO after steroid pulse therapy tended to be higher than those of five patients without improvement by the therapy. After the therapy the signal intensity ratios of muscle and retrobulbar fat were significantly decreased in ten patients with favorable response. Our data suggested that high signal intensity in STIR may reflect edema caused by acute inflammation associated with GO. In conclusion, MRI may be a useful tool for determining the indication and prognosis of steroid pulse therapy. We strongly recommend measuring the signal intensity of eye muscle as well as muscle thickness in MRI to evaluate the activity of GO.

Adipose Tissue↗
PubMed1992

[Liver abscess formation after treatment of liver cancer by arterial injection using adriamycin/mitomycin C oil suspension (ADMOS)].

Of 210 patients with hepatocellular carcinoma (n = 135), metastatic liver cancer (n = 71) and cholangiocarcinoma (n = 4) who underwent intra-arterial infusion of adriamycin and/or mitomycin C oil suspension (ADMOS) and cisplatin, and both regimens, pyogenic liver abscess occurred in seven (3.3%). The percentages of abscess formation in the respective types of liver cancer were 0.8, 7.0 and 25%. These differences among the three types of liver cancer were attributed to the volume of the tumor vascular beds to be embolized, which might determine the relative amount or regional Lipiodol retention in the tumor and normal liver tissue. Four of seven patients with hepatic abscess had received the intra-arterial infusion of ADMOS, and their angiographic findings showed sequential decreases in the vascular beds of the tumor in comparison with those of previous infusion procedures; all had hypovascular liver tumors angiographically. We have never experienced this complication in other treatments such as embolization of the hepatic arteries and intra-arterial infusion of water-soluble anticancer drugs alone. These results suggest that the most important factor leading to abscess formation is the ischemic destruction of the intrahepatic ducts secondary to occlusion of the peribiliary arterial plexus by Lipiodol and/or the direct effects of anticancer drugs on these vessels. To avoid this complication, the volume of Lipiodol used for intraarterial infusion therapy should be carefully determined, especially when the patient has hypovascular tumors of the liver and a history of multiple previous intraarterial infusion procedures of anticancer drug. The use of ADMOS should be avoided in patients with hypovascular tumors of the liver such as secondary deposits and cholangiocarcinoma.

Adenoma, Bile Duct↗
PubMed1992

Effect of triphenyltin chloride on the release of histamine from mast cells.

The effects of triphenyltin chloride (TPTC) on the release of histamine from rat and mouse mast cells in vitro and in vivo were investigated. The results obtained are summarized as follows: (a) At doses between 1 and 3 mg/kg, TPTC inhibited the dye leakage due to passive cutaneous anaphylaxis mediated by IgE antibody in mouse ear. At the same doses, TPTC inhibited the swelling due to reversed cutaneous anaphylaxis mediated by IgG antibody in rat. However, TPTC did not affect dye leakage due to histamine, serotonin, and LTC4 in rat skin; (b) Histamine release by antigen and IgE antibody in rat peritoneal cavity was inhibited by the administration of TPTC at doses between 0.3 and 3 mg/kg; (c) Histamine release by calcium ionophore A 23187 from purified rat peritoneal mast cells in vitro was inhibited by TPTC at concentrations between 10(-7) and 10(-6) M. At the same concentration, TPTC, itself, caused neither the release of histamine nor any change in cell viability which was supported by the activity of lactate dehydrogenase (LDH) from purified rat peritoneal mast cells. All this evidence suggests that TPTC has an inhibitory effect on the release of histamine from mast cells without direct cytotoxicity.

Animals↗
PubMed1992

Inhibition of prostaglandin delta 13 reductase activity in rabbit kidney cortex by glutathione disulfide.

t-Butyl hydroperoxide and H2O2-Fe(2+)-EDTA-glutathione system which produces hydroxyl radicals did not affect the 15-hydroxy prostaglandin dehydrogenase activity in rabbit kidney cortex. On the other hand, H2O2-Fe(2+)-EDTA-glutathione system inhibited the prostaglandin delta 13 reductase activity. Mannitol, a scavenger of hydroxyl radicals, had no effect on the inhibitory action of this system, indicating that the effect of H2O2-Fe(2+)-EDTA-glutathione system on the prostaglandin delta 13 reductase may not be due to produced hydroxyl radicals. As a result of further investigation, it was shown that glutathione disulfide, which is synthesized concomitantly with hydroxyl radicals from H2O2-Fe(2+)-EDTA-glutathione, inhibited the prostaglandin delta 13 reductase activity. These results suggest that hydroperoxides and hydroxyl radicals may not be likely candidates for the modulator of the catabolism of prostaglandins in the kidney cortex, and that glutathione disulfide has the potential to modulate the prostaglandin catabolism by affecting the prostaglandin delta 13 reductase activity.

15-Oxoprostaglandin 13-Reductase↗
PubMed1992

Telescience testbed examination aboard Japanese Experiment Module (JEM): life and material science experiments.

A telescience ground testbed experiment was conducted by the National Space Development Agency of Japan (NASDA) at the Tsukuba Space Center in March 1991. The objectives of the ground testbed experiment were to extract scientists' requirements for a communication method, to evaluate the influence of transmission delay and capacity on experiment operations, and to evaluate performance and functions of the system for the testbed experiment. The microscopic operations experiment, the image furnace experiment and the onboard training experiment were selected as typical ground testbed experiments. In these experiments, motion video transmission at 320 kbps was acceptable for observing the experiments and communicating between the principal investigator and the payload specialist. In the microscopic operations experiment, motion video transmission at 1.5 Mbps or more was required for detailed observation. A 4-second transmission delay (roundtrip) was allowable for mutual communication.

Aerospace Medicine↗
PubMed1992

Effect of tert-butyl hydroperoxide on cyclooxygenase and lipoxygenase metabolism of arachidonic acid in rabbit platelets.

The effect of tert-butyl hydroperoxide (t-BOOH) on the formation of thromboxane (TX) B2, 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) and 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) from exogenous arachidonic acid (AA) in washed rabbit platelets was examined. t-BOOH enhanced TXB2 and HHT formation at concentrations of 8 microM and below, and at 50 microM it inhibited the formation, suggesting that platelet cyclooxygenase activity can be enhanced or inhibited by t-BOOH depending on the concentration. t-BOOH inhibited 12-HETE production in a dose-dependent manner. When the platelets were incubated with 12-hydroperoxy-5,8,10,14-eicosatetraenoic acid (12-HPETE) instead of AA, t-BOOH failed to inhibit the conversion of 12-HPETE to 12-HETE, indicating that the inhibition of 12-HETE formation by t-BOOH occurs at the lipoxygenase step. Studies utilizing indomethacin (a selective cyclooxygenase inhibitor) and desferrioxamine (an iron-chelating agent) revealed that the inhibitory effect of t-BOOH on the lipoxygenase is not mediated through the activation of the cyclooxygenase and that this effect of t-BOOH is due to the hydroperoxy moiety. These results suggest that hydroperoxides play an important role in the control of platelet cyclooxygenase and lipoxygenase activities.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1992

Effects of fatty acyl-coenzyme A esters on prostaglandin synthesis in rabbit kidney medulla microsomes.

The effects of fatty acyl-coenzyme A (CoA) esters (palmitoyl-, stearoyl-, oleoyl-, linoleoyl- and arachidonoyl-CoA) on the synthesis of prostaglandins (PGs) in rabbit kidney medulla microsomes were examined. Medulla microsomes were incubated with arachidonic acid in 0.1 M-Tris/HCl buffer (pH 8.0) containing reduced glutathione and hydroquinone and the formed PGE2, PGF2 alpha and PGD2 were measured by high-pressure liquid chromatography using 9-anthryldiazomethane for derivatization. Under our incubation conditions rabbit kidney medulla was found to produce PGE2 mainly. The addition of fatty acyl-CoA esters inhibited total PG formation (the sum of PGE2, PGF2 alpha and PGD2) in a dose-dependent manner. Palmitoyl-, stearoyl- and oleoyl-CoA were about 10 times more potent than linoleoyl- and arachidonoyl-CoA as inhibitors of total PG formation. Linoleic acid was slightly more effective than linoleoyl-CoA, while palmitic acid had no influence on PG formation. All the fatty acyl-CoA esters inhibited the formation of PGE2. Simultaneously, the production of PGF2 alpha and PGD2 was increased. These results suggest that the CoA derivatives of palmitic, stearic and oleic acids have the potential to modulate PGE2, PGF2 alpha and PGD2 synthesis by affecting the activities of both-cyclooxygenase and endoperoxide E2 isomerase.

Acyl Coenzyme A↗
PubMed1992

Role of magnetic resonance imaging in thyroid-associated ophthalmopathy: its predictive value for therapeutic outcome of immunosuppressive therapy.

To investigate the efficacy of magnetic resonance imaging (MRI) in the assessment of thyroid-associated ophthalmopathy (TAO), 51 patients with TAO were evaluated by ophthalmologic examinations and MRI at 0.5 T. Thickness of extraocular muscles (EM) was measured by T1-weighted image. Signal intensities of EM and orbital connective tissue (OCT) were measured by short inversion time inversion recovery (STIR) image and expressed as a ratio by comparison to the signal intensity of cerebral substantia alba (SI, signal intensity ratio). Significant enlargement of one or more EM was observed in 86% of patients with TAO, and SI of EM (2.15 +/- 0.63, mean +/- SD) was significantly increased compared with control values (n = 16; 1.35 +/- 0.33; t test, p < 0.01). SI of OCT tended to be greater than that in the control group, although the difference was not significant. There was a significant positive correlation between thickness of EM and severity of ophthalmopathy, assessed as an ophthalmopathy index (p < 0.05). SI of neither EM nor OCT correlated with the severity of the eye disease. To investigate whether MRI findings could predict the outcome of methylprednisolone pulse therapy, we studied 23 patients with TAO who received this treatment. SI of EM and OCT in the 12 patients giving favorable responses were significantly greater than those in the 11 patients without good response (t test, p < 0.01). On the other hand, the thickness of eye muscles did not correlate with the outcome of treatment except for that of medial rectus muscle. There was a significant correlation between SI of EM and that of OCT (r = 0.78, p < 0.01), suggesting possible similar pathologic processes in these tissues in TAO.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

The inhibitory effect of the combination of antineoplaston A-10 injection with a small dose of cis-diamminedichloroplatinum on cell and tumor growth of human hepatocellular carcinoma.

The inhibitory effects of a combination of Antineoplaston A-10 Injection with a small dose of cis-diamminedichloroplatinum (CDDP) on cell and tumor growth was tested in vitro and in vivo settings. A human hepatocellular carcinoma cell line (KIM-1) was used for the cell growth and transplanted tumor growth studies. In the cell growth study, one-hour exposure of KIM-1 cells to CDDP in the medium at concentrations of 0.5, 1.0, and 2.0 micrograms/ml inhibited cell growth dose-dependently. Continuous exposure of cultured cells to Antineoplaston A-10 Injection at concentrations of 4, 6, and 8 mg/ml also inhibited tumor growth dose-dependently. The combination of 0.5 microgram/ml CDDP and 6 mg/ml A-10 Injection inhibited cell growth more than did each agent individually. Electron microscopic study showed well-maintained organelle structures in Antineoplaston A-10 Injection-treated cells compared to CDDP-treated cells. alpha-Fetoprotein (AFP) production by 10(4) cells in 48 h increased in the A-10 Injection-treated and A-10 Injection+CDDP-treated groups as the concentration of these agents increased. In the tumor growth study, daily administration of Antineoplaston A-10 Injection 75 mg with once a week administration of 20 micrograms of CDDP for 5 weeks inhibited transplanted tumor growth in athymic mice after 33 days of treatment, while administration of 75 mg of A-10 Injection or 20 or 60 micrograms of CDDP alone showed no significant inhibition of tumor growth.

Animals↗
PubMed1992

Survival rate of extremely low birthweight infants and its effect on the amendment of the Eugenic Protection Act in Japan.

Because of the increasing survival rate of extremely low birthweight infants in recent years, the viability limit in the Eugenic Protection Act in Japan was amended from 24 to 22 completed weeks of gestation. The Japan Pediatric Society's survey on the outcome of infants born in 1990 focused on infants born before 24 weeks gestation and less than 500 g. The survival rates of infants born in 23, 22 and before 22 weeks gestation overall at 511 hospitals throughout Japan were 43/118 (36%), 3/36 (8%) and 0/8 (0%), respectively. Of 16 infants, none weighing less than 400 g at birth survived but 16 (12%) of 50 infants between 400 and 499 g survived. Up-to-date statistical data is essential to the amendment of the concept of viability and subsequent ethical decision-making on extremely low birthweight infants.

Birth Weight↗
PubMed1992

[13C] breath test of medium-chain triglycerides and oligosaccharides in neonates.

It is suitable to examine the utilization of carbohydrates and fats using stable isotope-labelled substrates in neonates because of their non-radioactivity. Administering medium-chain triglycerides (MCT) and oligosaccharides is of use in enteral nutrition for a patient with a limited water intake such as a neonate. In this study, the oxidation of MCT and maltose administered orally as an energy supplement in neonates has been examined using a stable isotope-labelled breath test. Five normal term neonates and five growing preterm infants were given [13C]-trioctanoin orally and three growing preterm infants were given [13C]-glucose and [13C]-maltose orally. The [13C] enrichment in carbon dioxide was analyzed by isotope ratio mass spectrometry, and oxidation rates over 6 hr and 12 hr respectively, were calculated. The oxidation rates for [13C]-octanoin after 6 hr were 46.2 +/- 3.6% in preterm infants and 53.5 +/- 13.8% in normal neonates, respectively (no significant difference), and 58.4 +/- 9.4% and 52.8 +/- 6.0% for [13C]-glucose and [13C]-maltose, respectively (not significant). The results demonstrate that orally administered MCT and maltose are oxidized sufficiently in preterm infants.

Breath Tests↗
PubMed1992

Glisoprenins, new inhibitors of acyl-CoA: cholesterol acyltransferase produced by Gliocladium sp. FO-1513. I. Production, isolation and physico-chemical and biological properties.

Gliocladium sp. FO-1513 was found to produce novel inhibitors of acyl-CoA: cholesterol acyltransferase (ACAT). Two active compounds, designated glisoprenins A and B, were isolated from the culture broth of the producing strain by a conventional method. The IC50 values of glisoprenins A and B for ACAT activity were 46 and 61 microM in an enzyme assay using rat liver microsomes, and 1.2 and 0.57 microM in a J774 macrophage assay, respectively.

Animals↗
PubMed1992

New cyclodepsipeptides, enniatins D, E and F produced by Fusarium sp. FO-1305.

New cyclodepsipeptides named enniatins D, E and F were isolated from the culture broth of Fusarium sp. FO-1305 as inhibitors of acyl-CoA:cholesterol acyltransferase (ACAT). The respective structures of enniatins D, E and F were determined to be cyclo[D-alpha-hydroxyisovaleryl(D-Hiv)-L-N-methylleucinyl(L- Me-Leu)-D-Hiv-L-N-methylvalinyl(L-Me-Val)-D-Hiv-L-Me-Val], a mixture of cyclo-[D-Hiv-L-Me-Leu-D-Hiv-L-N-methylisoleucinyl(L-Me-Ile)-D-Hiv- L-Me-Val] and cyclo(D-Hiv-L-Me-Ile-D-Hiv-L-Me-Leu-D-Hiv-L-Me-Val), and cyclo(D-Hiv-L-Me-Leu-D-Hiv-L-Me-Ile-D-Hiv-L-Me-Ile) by spectral analyses and chemical degradation. The IC50 values of enniatins D, E and F for ACAT activity in an enzyme assay using rat liver microsomes were calculated to be 87, 57 and 40 microM, respectively.

Animals↗
PubMed1992

Anthracycline metabolites from baumycin-producing Streptomyces sp. D788. I. Isolation of antibiotic-blocked mutants and their characterization.

Biosynthetically blocked mutants were obtained from a baumycin-producing Streptomyces sp. D788 newly isolated from soil. The first mutant isolated was a baumycin-negative but daunorubicin-accumulating mutant with a loss of 4'-substitution activity, from which all other blocked mutants were successively derived. These included a known 11-deoxydaunorubicin-producing mutant and several new types of mutants which produced mainly 10-carboxy-13-deoxocarminomycin, 10-methoxycarbonyl-13-deoxocarminomycin, their 11-deoxy derivatives or a precursor aglycone, respectively. In this paper, all the anthracycline components produced by the parent strain and its two known blocked mutants, a daunorubicin producer and a 11-deoxydaunorubicin producer, are also determined by HPLC and five new components are isolated. Cytotoxicities in vitro of all the components against L1210 cell culture are also described.

Animals↗
PubMed1992

Inhibition of acyl-CoA: cholesterol acyltransferase activity by cyclodepsipeptide antibiotics.

The effect was studied of the fungal cyclodepsipeptide antibiotics beauvericin and seven distinct enniatins on acyl-CoA: cholesterol acyltransferase (ACAT) activity. In an enzyme assay using rat liver microsomes, all the compounds were found to inhibit ACAT activity. The drug concentration that caused 50% inhibition (IC50 value) of the enzyme activity was determined to be 3.0 microM for beauvericin, indicating that the compound is one of the most potent ACAT inhibitors of microbial origin. Enniatins exhibited much higher IC50 values of 22 to 110 microM. More hydrophobic enniatins showed more potent inhibitory activity. Furthermore, the ACAT inhibitory activity was evaluated as inhibition of cholesteryl ester formation in a cell assay using J774 macrophages. Calculation of the ratio, CD50 value (the drug concentration causing 50% cell damage)/IC50 value of cholesteryl ester formation, indicated that beauvericin shows the highest specificity. These data indicate that beauvericin is one of the most potent and specific ACAT inhibitors of microbial origin.

Animals↗