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Biomedical subjects

Y Yamane

Publications and source records attributed to Y Yamane.

At least 109 records · Page 6Linked to original sources
PubMed1997

Inhibitory effect of nicotinamide to paraquat toxicity and the reaction site on complex I.

The inhibitory effect and mechanism of action of nicotinamide to paraquat toxicity were studied in male Sprague-Dawley rats. Proteins of submitochondrial particles (SMP), especially of mol. wt. 25-30 kDa, in rat lungs were destroyed by paraquat radicals, and aggregated protein bands approximately 100 kDa were observed by polyacrylamide electrophoresis. The competitive inhibition effects were observed of nicotinamide on NADH oxidation by paraquat via SMP in rat lungs and the Ki was 9.3 mM. The inhibitory effects of nicotinamide on lipid peroxidation by paraquat with rat lung and liver SMP were verified. The times of occurrence of dyspnea and death in rats after paraquat exposure were delayed by nicotinamide administration. The activity of NADH: ubiquinone reaction of NADH:ubiquinone oxidoreductase (complex I) in rat lung was reduced 24 h after paraquat exposure, and was protected by nicotinamide. The activity of NADH:ferricyanide reaction of complex I was, however, reduced by administration not only of paraquat but also nicotinamide. These results imply that nicotinamide is inhibitory to paraquat toxicity. Nicotinamide, paraquat, and ferricyanide may react at overlapping sites on complex I.

Animals↗
PubMed1997

Effects of organophosphorous compounds on fatty acid compositions and oxidative phosphorylation system in the brain of rats.

Effects of organophosphorous compounds, O,O-dimethyl O-4-nitro-m-tolyl phosphorothioate (MEP), O-ethyl O-p-nitrophenyl phenylphosphonothioate (EPN) and O-(4-cyanophenyl) O-ethyl phenylphosphonothioate (CYP), on the fatty acid composition and the subsequent effects on the oxidative phosphorylation system in the brain of rats were studied. After 6 days exposure in pesticides, polyunsaturated fatty acids in brain free fatty acid fractions of CYP treated rats decreased, and the unsaturation index in them were lower than those in the control rats. The polyunsaturated/saturated ratio (P/S ratio) in brain total lipids of CYP treated rats was lower than that in the control. The fatty acid composition in the brain of EPN treated rats had the same inclination as that of CYP treated rats. In the P/S ratio and unsaturation index in serum no difference was observed between CYP treated rats and the control, therefore CYP could affect the fatty acid composition in the rat brain directly. Free fatty acid contents in the brain of EPN and CYP treated rats decreased after 6 days exposure. Activities of complex I of brains were significantly higher in the EPN and CYP exposed rats than in the control rats in spite of the fact that no difference of ATP productivity was observed between them. These results suggest that EPN and CYP may affect the free fatty acid content, especially the polyunsaturated fatty acid content and consequently the enzyme activities in the oxidative phosphorylation system in the brain. Those phenomena, however, were not observed after 28 days exposure in pesticide, therefore those effects may be a passing phenomenon in an acute stage.

Animals↗
PubMed1997

Children's smoking habits in an agricultural community in Japan and the importance of a no smoking program integrating family, school and community health.

The object of this study is to establish a model of integration of the health promotion projects which have been planned separately by schools and communities so far in an agricultural area in Japan, to solve the problem of children's smoking. The subjects of the study were 10-15 y old schoolchildren and their parents. The questionnaires were completed by the children themselves at school and also by their parents at home, in July 1995. One fourth of the junior high school boys had ever tried smoking, while most of their parents did not notice that their children were smoking. More than half of the children who had ever tried smoking mainly acquired tobacco from their homes. One tenth of them were prompted to smoke by their fathers or other relatives. To develop a health promotion project for children which includes prevention of smoking, the provision of a health education program and an environment which encourages health are important for children. The project should also be community-based because participation of local inhabitants in the project gives it additional impetus. In order to promote the comprehensive health of children, we emphasize the importance of setting up a healthy district plan based on the health policy of the general community.

Adolescent↗
PubMed1997

Diagnosis of chronic pancreatitis using noninvasive tests of exocrine pancreatic function--comparison to duodenal intubation tests.

The diagnosis of chronic pancreatitis usually is based on imaging studies, pancreatic function tests, and the presence of characteristic clinical features. In Japan, diagnostic criteria for chronic pancreatitis were established in 1983 and revised in 1995. Under the new criteria, the secretin test (a duodenal intubation test) and the combination of noninvasive tests, N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA) and fecal chymotrypsin (FCT), have been recommended for evaluating exocrine pancreatic function in patients with chronic pancreatitis. In the present study, the diagnostic value of these two noninvasive tests was compared to the secretin test. Although noninvasive tests are less sensitive and specific for determining exocrine pancreatic impairment than the secretin test, greater reliability for diagnosing chronic pancreatitis can be obtained by performing the BT-PABA and fecal chymotrypsin tests simultaneously. Combining BT-PABA and FCT is easy and useful and should be performed at least twice to obtain reliable results.

4-Aminobenzoic Acid↗
PubMed1997

Influence of Oxygen and Glucose on Primary Metabolism and Astaxanthin Production by Phaffia rhodozyma in Batch and Fed-Batch Cultures: Kinetic and Stoichiometric Analysis.

The influence of the oxygen and glucose supply on primary metabolism (fermentation, respiration, and anabolism) and astaxanthin production in the yeast Phaffia rhodozyma was investigated. When P. rhodozyma grew under fermentative conditions with limited oxygen or high concentrations of glucose, the astaxanthin production rate decreased remarkably. On the other hand, when the yeast grew under aerobic conditions, the astaxanthin production rate increased with increasing oxygen uptake. A kinetic analysis showed that the respiration rate correlated positively with the astaxanthin production rate, whereas there was a negative correlation with the ethanol production rate. The influence of glucose concentration at a fixed nitrogen concentration with a high level of oxygen was then investigated. The results showed that astaxanthin production was enhanced by an initial high carbon/nitrogen ratio (C/N ratio) present in the medium, but cell growth was inhibited by a high glucose concentration. A stoichiometric analysis suggested that astaxanthin production was enhanced by decreasing the amount of NADPH required for anabolism, which could be achieved by the repression of protein biosynthesis with a high C/N ratio. Based on these results, we performed a two-stage fed-batch culture, in which cell growth was enhanced by a low C/N ratio in the first stage and astaxanthin production was enhanced by a high C/N ratio in the second stage. In this culture system, the highest astaxanthin production, 16.0 mg per liter, was obtained.

Journal Article↗
PubMed1997

Heterogeneity of myocardial fluoro-18 2-deoxyglucose uptake in patients with apical hypertrophic cardiomyopathy.

We have shown that myocardial glucose metabolism is heterogeneous in patients with hypertrophic cardiomyopathy. It is not known, however, whether glucose metabolism is impaired in patients with apical hypertrophic cardiomyopathy, which is fairly common in Japan. We studied 7 patients with apical hypertrophic cardiomyopathy and 5 normal subjects using fluoro-18 2-deoxyglucose (FDG) and positron emission tomography (PET). We calculated regional FDG fractional uptake and the inter-regional coefficient of variation (CV) of FDG fractional uptake in the interventricular septal, anteroapical, and posterolateral regions. The regional FDG fractional uptake was similar in the 2 groups and among the 3 different segments within each group. However, the inter-regional CV of FDG fractional uptake was increased in the anteroapical wall segment of the patient group compared with the control group and also with the other 2 regions in the patient group. The results did not differ when we studied another 5 patients and 6 normal control subjects with a PET scanner with higher spatial resolution. These data suggest that myocardial glucose metabolism may be impaired in the anteroapical wall segment of patients with apical hypertrophic cardiomyopathy.

Adult↗
PubMed1997

Early serodiagnosis of porcine reproductive and respiratory syndrome virus infection of pigs by detection of slow-reacting and complement-requiring neutralizing antibody.

In order to evaluate and enhance the sensitivity of the neutralization (NT) test for detecting antibody in pigs infected with porcine reproductive and respiratory syndrome (PRRS) virus, the effect of altered incubation conditions and complement use on neutralizing (NT) antibody titer were investigated. Higher NT antibody titers were consistently obtained by addition of 20% guinea pig fresh serum to virus-serum mixtures in NT tests. Furthermore, the complement-requiring NT antibody titer increased in many serum samples when the virus-serum mixtures, rather than being incubated at 37 degrees C for 60 min, were incubated first at 4 degrees C for 48 hr and then with a complement at 37 degrees C for 60 min. The slow-reacting and complement-requiring NT antibody was detected as early as 8 days post-inoculation. It was detected in sera collected at 8 to 28 days post-inoculation and was sensitive to 2-mercaptoethanol treatment. Sera collected at 35 to 44 days post-inoculation contained 2-mercaptoethanol resistant NT antibodies. These results indicate that the modified NT test is useful for early serodiagnosis of PRRS virus infection through detection of higher NT antibody titers, and in detecting them earlier.

Animals↗
PubMed1997

Myocardial glucose metabolism is different between hypertrophic cardiomyopathy and hypertensive heart disease associated with asymmetrical septal hypertrophy.

Myocardial glucose metabolism has been shown to be heterogeneous in patients with hypertrophic cardiomyopathy (HCM). We tested the hypothesis that myocardial glucose metabolism differs between patients with HCM and those with hypertensive heart disease (HHD) associated with asymmetrical septal hypertrophy. We studied 12 patients with HCM, 7 HHD patients associated with asymmetrical septal hypertrophy using 18F 2-deoxyglucose (FDG) and positron emission tomography. We calculated % FDG fractional uptake in the inter-ventricular septum and posterolateral wall. Heterogeneity of FDG uptake was evaluated by % interregional coefficient of variation of FDG fractional uptake in each wall segment. In both the interventricular septum and posterolateral wall, % FDG fractional uptake was not significantly different between the two groups. The % interregional coefficient of variation for both interventricular septum (10.6 +/- 1.6 vs. 4.1 +/- 0.5, p < 0.01) and posterolateral wall (5.9 +/- 0.7 vs. 3.8 +/- 0.5, p < 0.05) was significantly larger in patients with HCM than in HHD patients associated with asymmetrical septal hypertrophy. Echocardiography demonstrated that the degree of asymmetrical septal hypertrophy was similar between the two groups. These results suggest that myocardial glucose metabolism may be more heterogeneous in patients with HCM compared to HHD patients associated with asymmetrical septal hypertrophy, although the left ventricular shape is similar. The difference in the heterogeneity might have resulted from differences in the pathogeneses of the two diseases.

Adolescent↗
PubMed1997

Chloroquine induces basophilic differentiation of HL-60 cells.

Many agents have been known to induce the differentiation of HL-60 cells. However, only a small number of reports on the basophilic differentiation of this cell line are known. In this study we show that the exposure of HL-60 cells to chloroquine induces to differentiate into basophils. This chloroquine-induced change suggests that the increase in intracellular pH and the upregulation of p21 with subsequent downregulation of cdc2 kinase are triggers for basophilic differentiation of this cell line.

Basophils↗
PubMed1997

[Participatory action-research in the development of health policies for Izumo City, Japan].

The method of participatory action-research has been introduced in planning and implementing health and welfare projects for the elderly in Izumo City since 1993. Public health researchers have participated in the projects with other related administrative sectors, citizen and non-profit organizations. This study analyzes the establishment and implementation of health policies of Izumo from the following five aspects: policy-making, priority, education, intersectoral cooperation and community development. The participatory action-research method was useful for developing the ability of health-staff to work with citizens; for integrating community care and community development; for using community resources effectively for primary health care; and for developing community-based education of citizens, medical students and health staff. This method can be and should be adopted for strengthening the policy-making ability of public health researchers who learn through cooperation with citizens and non-profit organizations.

Community Participation↗
PubMed1997

Stimulated glucose uptake in the ischemic border zone: its dependence on glucose uptake in the normally perfused area.

UNLABELLED: During acute regional myocardial ischemia, a "border zone" exists where the spatial distributions of blood flow and substrate uptake show gradual changes. We investigated the relationship between blood flow and glucose uptake in the border zone during acute regional ischemia. METHODS: Newly developed quantitative autoradiography using imaging plates and two long-lived radioisotopes was applied to rat hearts subjected to 30 min of left coronary artery occlusion. Blood flow, glucose uptake and fatty acid uptake was assessed with 4-[N-methyl-14C]iodoantipyrine, 2-deoxy-D-[1-3H]glucose (3H-DG) and beta-methyl[1-14C]heptadecanoic acid (14C-BMHDA), respectively. RESULTS: In rats showing 3H-DG uptake in the normally perfused area (Norm) of 254 +/- 96 Bq/mg (high-DG) and 56 +/- 20 Bq/mg (low-DG) (n = 4 for each), 3H-DG uptake in the border zone was 148 +/- 52 Bq/mg and 58 +/- 15 Bq/mg (p < 0.05 high- versus low-DG), respectively. The relationship between blood flow and 3H-DG uptake in the border zone was altered by the different 3H-DG uptake levels in Norm. In high-DG, 3H-DG uptake in the border zone was reduced significantly according to the decrease in the percentage of blood flow. However, in low-DG, no significant differences in 3H-DG uptake were found among the regions in the border zone with different levels of the percentage of blood flow, except in the region with 10%-19% of the percentage of blood flow. In the border zone, the percentage of 3H-DG uptake per unit blood flow normalized to that in Norm increased according to the decrease in the percentage of blood flow, and this increase was steeper in low-DG than in high-DG (p < 0.0005). The percentage of 14C-BMHDA uptake was lower than the percentage of 3H-DG uptake (27 +/- 3% versus 78 +/- 18% of that in Norm, p < 0.0005) in the peripheral ischemic area. CONCLUSION: The relationship between blood flow and glucose uptake in the ischemic border zone was altered by the different glucose uptake levels in Norm. Glucose uptake in the border zone was higher in rats with higher glucose uptake levels in Norm, suggesting that glucose uptake in the border zone stimulated by ischemia can be accelerated still more by humoral factors.

Animals↗
PubMed1997

[A case of thymic carcinoma with brain metastasis].

A 43-year-old female with a thymic carcinoma spreading to the extrathorac region is reported. She had received radiation and chemotherapy, after that thymic carcinoma was extirpated. Five months later, the patient was noticed to have a right side hemiparesis, following consciousness disturbance. CT and MRI revealed a left thalamic mass with a heterogenous enhancement effect. The tumor was diminished dramatically due to radiation. Metastasis of thymic carcinoma to the central nervous system is discussed.

Adult↗
PubMed1996

Coordinated induction of MRP/GS-X pump and gamma-glutamylcysteine synthetase by heavy metals in human leukemia cells.

We recently reported that GS-X pump activity, as assessed by ATP-dependent transport of the glutathione-platinum complex and leukotriene C4, and intracellular glutathione (GSH) levels were remarkably enhanced in cis-diamminedichloroplatinum(II) (cisplatin)-resistant human leukemia HL-60 cells (Ishikawa, T., Wright, C. D., and Ishizuka, H. (1994) J. Biol. Chem. 269, 29085-29093). Now, using Northern hybridization and RNase protection assay, we provide evidence that the multidrug resistance-associated protein (MRP) gene, which encodes a human GS-X pump, is expressed at higher levels in cisplatin-resistant (HL-60/R-CP) cells than in sensitive cells, whereas amplification of the MRP gene is not detected by Southern hybridization. Culturing HL-60/R-CP cells in cisplatin-free medium resulted in reduced MRP mRNA levels, but these levels could be induced to rise within 30 h by cisplatin and heavy metals such as arsenite, cadmium, and zinc. The increased levels of MRP mRNA were closely related with enhanced activities of ATP-dependent transport of leukotriene C4 (LTC4) in plasma membrane vesicles. The glutathione-platinum (GS-Pt) complex, but not cisplatin, inhibited ATP-dependent LTC4 transport, suggesting that the MRP/GS-X pump transports both LTC4 and the GS-Pt complex. Expression of gamma-glutamylcysteine synthetase in the cisplatin-resistant cells was also co-induced within 24 h in response to cisplatin exposure, resulting in a significant increase in cellular GSH level. The resistant cells exposed to cisplatin were cross-resistant to melphalan, chlorambucil, arsenite, and cadmium. These observations suggest that elevated expression of the MRP/GS-X pump and increased GSH biosynthesis together may be important factors in the cellular metabolism and disposition of cisplatin, alkylating agents, and heavy metals.

ATP-Binding Cassette Transporters↗
PubMed1996

Structures of five sulfated hexasaccharides prepared from porcine intestinal heparin using bacterial heparinase. Structural variants with apparent biosynthetic precursor-product relationships for the antithrombin III-binding site.

Porcine intestinal heparin was extensively digested with Flavobacterium heparinase and size-fractionated by gel chromatography. Subfractionation of the hexasaccharide fraction by anion exchange high pressure liquid chromatography yielded 10 fractions. Six contained oligosaccharides derived from the repeating disaccharide region, whereas four contained glycoserines from the glycosaminoglycan-protein linkage region. The latter structures were reported recently (Sugahara, K., Tsuda, H., Yoshida, K., Yamada, S., de Beer, T., and Vliegenthart, J.F.G. (1995) J. Biol. Chem. 270, 22914-22923). In this study, the structures of one tetra- and five hexasaccharides from the repeat region were determined by chemical and enzymatic analyses as well as 500-MHz 1H NMR spectroscopy. The tetrasaccharide has the hexasulfated structure typical of heparin. The five hexa- or heptasulfated hexasaccharides share the common core pentasulfated structure delta HexA(2S) alpha 1-4GlcN-(NS, 6S) alpha 1-4IdoA alpha/GlcA beta 1-4GlcN(6S) alpha 1-4GlcA beta 1-4GlcN (NS) with one or two additional sulfate groups (delta HexA, GlcN, IdoA, and GlcA represent 4-deoxy-alpha-L-threo-hex-4-enepyranosyluronic acid, D-glucosamine, L-iduronic acid, and D-glucuronic acid, whereas 2S, 6S and NS stand for 2-O-, 6-O-, and 2-N-sulfate, respectively). Three components have the following hitherto unreported structures: delta HexA(2S) alpha 1-4GlcN(NS, 6S) alpha 1-4GlcA beta 1-4GlcN(NS, 6S) alpha 1-4GlcA beta 1-4GlcN(NS,6S), delta HexA(2S) alpha 1-4GlcN(NS, 6S) alpha 1-4IdoA alpha 1-4GlcNAc(6S)-alpha 1-4GlcA beta 1-4GlcN(NS, 3S), and delta HexA(2S) alpha 1-4GlcN-(NS,6S) alpha 1-4IdoA (2S) alpha 1-4GlcNAc(6S) alpha 1-4GlcA beta 1-4GlcN(NS, 6S). Two of the five hexasaccharides are structural variants derived from the antithrombin III-binding sites containing 3-O-sulfated GlcN at the reducing termini with or without a 6-O-sulfate group on the reducing N,3-disulfated GlcN residue. Another contains the structure identical to that of the above heptasulfated antithrombin III-binding site fragment but lacks the 3-O-sulfate group and therefore is a pro-form for the binding site. Another has an extra sulfate group on the internal IdoA residue of this pro-form and therefore can be considered to have diverged from the binding site in the biosynthetic pathway. Thus, the isolated hexasacharides in this study include the three overlapping pairs of structural variants with an apparent biosynthetic precursor-product relationship, which may reflect biosynthetic regulatory mechanisms of the binding site.

Animals↗
PubMed1996

Effects of paraquat on mitochondrial electron transport system and catecholamine contents in rat brain.

The effects of paraquat on rat brain were studied. Activities of complex I (NADH: ubiquinone oxidoreductase) in mitochondrial electron transport system, lipid peroxidation and the amount of catecholamines in rat brain were measured after acute paraquat exposure. Complex I activities were significantly lower and lipid peroxides were higher in the brains of a paraquat-treated group than in those of a control group. Lipid peroxide in rat serum, however, did not increase after paraquat exposure. A study of the time dependency of paraquat effects disclosed that mitochondrial complex I activities in rat brain as well as those in rat lung and liver gradually decreased prior to the appearance of respiratory dysfunction. As compared to controls, the dopamine in rat striatum was significantly lower in the paraquat-treated group. These results suggest that paraquat after crossing the blood-brain barrier might be reduced to the radical in rat brain, which may damage the brain tissue, especially dopaminergic neurons in striatum. We therefore propose that cerebral damage should be taken into consideration on paraquat exposure. Patients may therefore need to be followed up after exposure to high doses of paraquat.

Animals↗
PubMed1996

Autocrine angiogenic vascular prosthesis with bone marrow transplantation.

Synthetic vascular prostheses are foreign bodies, so that blood coagulation can occur on their luminal surfaces, causing graft occlusion very frequently in prostheses of small diameter. A vascular prosthesis needs angiogenesis for endothelialization of the luminal surface, as endothelial cells have natural and permanent antithrombogenic properties. To induce capillary growth into the graft, we developed a method of transplanting bone marrow cells, which are primitive, strong enough to survive, and create blood cells, resulting in the inducement of capillary growth. In an animal experiment, marrow cells were infiltrated into the walls of long-fibril expanded polytetrafluoroethylene (ePTFE) vascular grafts. The grafts were implanted in the abdominal aortic position of 24 dogs autologously. Marrow cells survived and continued exogenous hemopoiesis for up to six months and were immunohistochemically reactive to basic fibroblast growth factor (bFGF). All the grafts older than three weeks had complete endothelialization and maintained their patency. Twenty grafts without bone marrow were implanted as controls. Endothelialization was present at anastomotic sites, but other areas were covered with fresh thrombi. Four out of seven control grafts were patent with endothelial cell lining at six months, but three were occluded and one of the four grafts was still covered with a thrombus layer. Bone marrow with its unique native properties produced autocrine angiogenicity in the graft.

Animals↗
PubMed1996

Basement membrane proteoglycans are of epithelial origin in rodent skin.

Basement membrane proteoglycans in mammalian skin comprise at least one chondroitin sulfate proteoglycan and heparan sulfate proteoglycans, including perlecan. In this study, the origins of basement membrane chondroitin sulfate proteoglycan and perlecan were investigated both in vivo and in vitro. For in vivo experiments, pieces of newborn rat epidermis obtained by dispase treatment were grafted onto athymic nude mice. Three and six weeks after grafting, immunofluorescence analysis of the grafted skin was carried out, using monoclonal antibodies specific for rat basement membrane chondroitin sulfate proteoglycan and rat and mouse perlecan. While the isolated rat epidermis was shown to completely lack rat basement membrane chondroitin sulfate proteoglycan and rat basement membrane heparan sulfate proteoglycans, including perlecan, immunofluorescence staining of tissue sections from the grafted sites on mice demonstrated the presence of rat basement membrane chondroitin sulfate proteoglycan and rat perlecan on interfollicular and follicular basement membranes including that separating dermal papillae from adjacent hair follicle epithelium. In contrast, the basement membranes of all dermal capillaries were positive for mouse perlecan, but negative for rat basement membrane chondroitin sulfate proteoglycan and rat perlecan, including the basement membranes of papillary dermal capillaries beneath the rat epidermis. These data suggest that basement membrane proteoglycans of the dermal-epidermal junction and hair follicle epithelium are of epidermal (epithelial) origin in vivo. Stratified rat keratinocytes cultured on a collagen matrix at the air-liquid interface showed the synthesis of perlecan, laminin 1, and type IV collagen in basement membranes, but not clearly detectable basement membrane chondroitin sulfate proteoglycan.

Animals↗