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Biomedical subjects

T Yoshimura

Publications and source records attributed to T Yoshimura.

At least 685 records · Page 38Linked to original sources
PubMed1986

Effect of high carbohydrate diet on serum gamma-glutamyl transpeptidase fraction pattern in Japanese young men.

Changes in the activity of serum gamma-glutamyl transpeptidase (gamma-GTP) and the percentage of the gamma-GTP fraction in healthy young men given a high carbohydrate diet (480-636 g/day, 80% of the total energy) for 21 days were examined. Serum total gamma-GTP activity showed no significant change in four healthy young volunteers who received high carbohydrate diet for 21 days. However, the percentage of the gamma-GTP (1) fraction increased significantly (P less than 0.01) from the basal level of 55.6 +/- 4.0% to 67.6 +/- 0.9% on day 10, and then decreased to 58.4 +/- 1.4% on day 21. When the experimental diet was replaced by usual diet, the percentage of the gamma-GTP (1) fraction returned to the same level as before the experiment. It is concluded from the results that the nutrient intake affects the percentage of gamma-GTP (1), but not the total serum gamma-GTP activity.

Adult↗
PubMed1986

Effect of high carbohydrate diet on serum lactate dehydrogenase isozyme pattern in Japanese young men.

Changes in the activity of serum lactate dehydrogenase (LDH) and the serum LDH isozyme pattern in healthy young men given a high carbohydrate diet (480-636 g/day, 80% of the total energy) for 21 days were examined. Serum total LDH activity showed no significant change in four healthy young volunteers who received high carbohydrate diet for 21 days. However, the percentage of LDH-4 increased significantly (P less than 0.01) from 8.5 +/- 2.4 to 10.9 +/- 1.9% after 21 days, as did also the percentage of LDH-5 (P less than 0.01) from 5.1 +/- 1.9 to 10.7 +/- 2.9%. The percentage of M-type LDH activity increased 30% during the experiment (P less than 0.05). It is concluded from the results that the high carbohydrate intake affects the percentage of LDH-4 and LDH-5, but not the total serum LDH activity.

Adult↗
PubMed1986

[A case of extraskeletal osteosarcoma of the retroperitoneum].

A case of extraskeletal osteosarcoma of the retroperitoneum in a 57-year-old woman is reported. A rapidly growing intra-abdominal tumor was noticed eight months before her death. The resected tumor, weighing 1.9 kg, consisted of a large amount of solid mucinous tissue with significant bony materials. Histologically, the tumor showed fibrosarcomatous, chondrosarcomatous and osteosarcomatous growth patterns. A diagnosis of osteosarcoma was made. The CT scan and autopsy findings confirmed that the tumor did not originate from the preexisting bones, but from the retroperitoneum. Differences distinguishing retroperitoneal osteosarcoma from other soft tissue sarcomas were also described from the histological point of view.

Female↗
PubMed1986

Significance of angiotensin sensitivity test for prediction of pregnancy-induced hypertension.

In 48 normotensive women with epidemiologic high-risk factors for pregnancy-induced hypertension, the angiotensin sensitivity test was performed serially between 26 and 32 weeks of gestation. If an effective pressor dose of less than 12 ng/kg per minute was considered to be a positive test result, 20 subjects were positive at 30 weeks of gestation and destined to develop pregnancy-induced hypertension. Of ten subjects with a false-positive test result, seven patients developed proteinuria and/or clinically significant edema without apparent hypertension, and only three subjects remained normal throughout their pregnancy. Twenty-eight subjects with negative test results had uneventful pregnancies. Before 30 weeks' gestation, it was difficult to identify all patients destined for pregnancy-induced hypertension. Although high false-positive test results were detected, these results suggest that an angiotensin sensitivity test at 30 weeks' gestation represents an appropriate means of identifying women who remain normal throughout pregnancy. Careful follow-up should be undertaken in all patients with positive test results.

Adult↗
PubMed1985

Effect of calcium supplementation on the vascular sensitivity to angiotensin II in pregnant women.

Pregnant women destined to develop pregnancy-induced hypertension lose refractoriness to the pressor effects of infused angiotensin II. The effect of calcium supplementation on the vascular sensitivity to angiotensin II was investigated in pregnant women. We administered orally 600 mg of calcium L-aspartate daily to 22 pregnant women from 20 weeks of gestation to delivery. The values for the effective pressor dose of angiotensin II in the calcium-supplemented women were compared with those in 72 nonsupplemented pregnant women. The vascular sensitivity was significantly decreased after calcium supplementation. The values for the effective pressor dose of angiotensin II in the calcium-supplemented patients were 18.1 +/- 1.2 ng/kg/min at 20 weeks of gestation, 32.2 +/- 2.6 ng/kg/min at the twenty-sixth week, 41.1 +/- 3.4 ng/kg/min at the thirtieth week, and 25.9 +/- 2.9 ng/kg/min at the thirty-sixth week (mean +/- SEM), while those in the nonsupplemented patients were 17.3 +/- 1.2, 17.7 +/- 1.6, 17.6 +/- 1.2, and 15.0 +/- 1.6 ng/kg/min, respectively. Assessment of the changes in the effective pressor dose of angiotensin II in the individual patients indicated that the percentile changes from 20 weeks of gestation in the calcium-supplemented patients were also significantly greater than those in 22 nonsupplemented patients. These findings suggest that calcium supplementation tends to reduce the vascular sensitivity in pregnancy. The present dosage of calcium did not affect the blood chemical parameters and did not reduce the blood pressure. The incidence of pregnancy-induced hypertension in the calcium-supplemented patients was 4.5%, which was smaller than that (21.2%) in the nonsupplemented patients. Although there is no clear explanation of the mechanisms involved in such an effect of calcium, the present results do provide evidence to support the idea that oral calcium intake can prevent the onset of pregnancy-induced hypertension.

Adult↗
PubMed1985

Interaction of clathrin with liposomes: pH-dependent fusion of phospholipid membranes induced by clathrin.

Clathrin, dissociated from coated vesicles of bovine brain and purified by gel chromatography, was found to interact with the lipid bilayer as shown by the spontaneous release of encapsulated fluorescent dye in liposome. Clathrin-induced dye release was enhanced at acidic pH in phosphatidylserine-containing vesicles. A strong correlation between dye release and fusion of liposomes was observed. In general, when there was a fast release of encapsulated dye induced by clathrin, a pH-dependent, clathrin-induced fusion was observed. Clathrin did not induce either dye release or fusion of egg phosphatidylcholine liposomes. The self-association of clathrin at low pH diminished the fusogenic activity. Fusion induced by clathrin at low pH could be stopped at pH above 5.0 and resumed by lowering the pH below 5.0. This suggests that the interaction of clathrin with phospholipid membranes can be regulated by pH.

Animals↗
PubMed1985

Identification of heme axial ligands of cytochrome c' from Alcaligenes sp. N.C.I.B. 11015.

The spectral properties of both ferric and ferrous cytochromes c' from Alcaligenes sp. N.C.I.B. 11015 are reported. The EPR spectra at 77 K and the electronic, resonance Raman, CD and MCD spectra at room temperature have been compared with those of the other cytochromes c' and various hemoproteins. In the ferrous form, all the spectral results at physiological pH strongly indicated that the heme iron(II) is in a high-spin state. In the ferric form, the EPR and electronic absorption spectra were markedly dependent upon pH. EPR and electronic spectral results suggested that the ground state of heme iron(III) at physiological pH consists of a quantum mechanical admixture of an intermediate-spin and a high-spin state. Under highly alkaline conditions, identification of the axial ligands of heme iron(III) was attempted by crystal field analysis of the low-spin EPR g values. Upon the addition of sodium dodecyl sulfate to ferric and ferrous cytochrome c', the low-spin type spectra were induced. The heme environment of this low-spin species is also discussed.

Alcaligenes↗
PubMed1985

Partition of divalent and total manganese in organs and subcellular organelles of MnCl2-treated rats studied by ESR and neutron activation analysis.

The possibility that Mn2+ is converted to other valency states in vivo was examined by measuring the ratio of Mn2+, determined by ESR, to total manganese, determined by neutron activation analysis combined with chemical separation, in various organs of control rats and rats treated with MnCl2. In control rats, the total manganese content was high in the thyroid, hypophysis, adrenal, pancreas, liver and kidney, but the Mn2+ contents of these organs were low. In rats treated with Mn2+, the total manganese contents of all organs increased, but the Mn2+ contents still remained low. With regard to subcellular distribution, the total manganese content was high in the nuclear and mitochondrial fractions of the liver and kidney, and in the microsomal and supernatant fractions of the pancreas. The ratio of Mn2+ to total manganese was relatively high in the microsomes of the liver and kidney of control rats, and in the nuclear fraction of the pancreas of Mn2+-treated rats. Thus, the distribution and behavior of manganese in the pancreas were different from those in other organs. Purified liver nuclei and mitochondria were demonstrated to contain manganese, indicating that manganese is tightly bound in each cellular compartment.

Animals↗
PubMed1985

Oxidation and reduction of cytochrome c bound to the phosphoprotein phosvitin.

The oxidation-reduction reactions and structural characteristics of phosvitin-bound cytochrome c were examined at various ratios of cytochrome c to phosvitin. At binding ratios below half the maximum, the rate constants for the oxidation reactions with cytochrome c oxidase and ferricyanide and the rate constants for the reduction reactions with cytochrome b2 and ascorbate were low, but at higher ratios these rate constants gradually increased to that of free cytochrome c and, in particular, the rate constant for oxidation by cytochrome c oxidase was raised to two to three times that of the free form. This binding-ratio dependence of the rate constants for the oxidation and reduction reactions was different from that of the net charge of the cytochrome c-phosvitin complex, implying that the negative charges of phosvitin are unlikely to modulate the rates. In contrast, the broadening of the NMR signals for the heme and methionine-80 methyl groups and the conformational transition in the vicinity of the heme moiety on change from the native to the cyanide-bound or urea-denatured form of cytochrome c showed a similar binding-ratio dependence to the rate constants for the oxidation and reduction reactions. Since the conformation and electronic structure in the heme environment of ferric and ferrous cytochromes c were not changed significantly by binding to phosvitin, and since the binding strength of cytochrome c to phosvitin at binding ratios below half the maximum is different from that at higher ratios, these findings suggest that a difference in the movement of cytochrome c in its complex with phosvitin may modulate its oxidation-reduction reactions.

Circular Dichroism↗
PubMed1985

Synthetic analogs of the active site of cytochrome P-450cam characterization of thiolpeptide fragment-hemin complexes by optical and ESR spectrometries.

Thiol-containing penta (Leu-Ala-Cys-Ser-Leu) and nona (Leu-Ala-Cys-Ser-Leu-Ile-Glu-Ser-Leu) peptides corresponding to residues 132-136 and 132-140, respectively, of apo-P450 from Psuedomonas putida were synthesized to examine heme-binding by the enzymes in the oxidized (ferric) form. The peptide-hemin complexes prepared in solution were characterized by their optical and ESR spectra. In these complexes without nitrogenous ligands, no ferric complexes in the low-spin state were observed, suggesting that simultaneous axial coordination of Cys-134 (thiolate) and Ser-139 (hydroxyl) of apo-P450cam to the heme is unlikely to occur. In the presence of nitrogenous ligands, such as py, Im and MeIm, the resulting complexes were good models of apo-P450cam-nitrogenous ligand adducts in the low-spin ferric state retaining a thiolate-Fe(III)-nitrogen axial coordination mode, as judged by their spectral pattern as well as by crystal field analysis of ESR g-values.

Amino Acid Sequence↗
PubMed1985

Sodium-induced aggregation of phosphatidic acid and mixed phospholipid vesicles.

Sodium-induced aggregations of sonicated vesicles prepared from synthetic phosphatidic acid and from its 1:1 mixtures with synthetic phosphatidylethanolamine and phosphatidylcholine were studied by turbidimetric measurements. The aggregation reactions were almost completely reversible on change in the Na+ concentration, pH or temperature. The threshold concentrations of Na+ for aggregations of pure dipalmitoylphosphatidic acid vesicles and mixed dipalmitoylphosphatidylethanolamine- and dimyristoylphosphatidylcholine-dipalmitoylphosphatidic acid vesicles were found to be 200, 310 and 550 mM, respectively, at 25 degrees C and pH 7.2. The hydrocarbon chain lengths of phosphatidic acid and phosphatidylethanolamine had little effect on the threshold concentrations. The threshold concentrations for phospholipid vesicles composed of phosphatidic acid alone or its 1:1 mixture with phosphatidylethanolamine were changed by varying either the pH or temperature, while that for phosphatidylcholine-phosphatidic acid vesicles was almost independent of the pH and temperature, implying that aggregation of the latter vesicles is induced by a somewhat different mechanism.

Dimyristoylphosphatidylcholine↗
PubMed1985

Alcohol and cancer in male Japanese physicians.

The relationship between alcohol and site-specific cancers was investigated in a follow-up study of 5,139 male Japanese physicians. Information on drinking habits was obtained by mail questionnaire in 1965, and cancer deaths over 12.7 years were analyzed with drinking habits classified into five categories; nondrinker, ex-drinker, occasional drinker, and daily drinker whose intake of alcohol was equivalent to less than 2 or 2 and more go of sake (1 go sake congruent to 27 ml alcohol). Both age and smoking habits were taken into account in the calculation of death rates based on man-years at risk. Logistic regression analysis was also performed on cummulative mortality data. Upper aerodigestive cancer was strongly associated with alcohol consumption, giving some confidence in the validity of the present study. Excluding ex-drinkers, the risk of stomach cancer and liver cancer was gradually increased from nondrinkers to daily drinkers with lower intake of alcohol, but no further increase was noted for daily drinkers with larger consumption. Logistic regression did not show any significant associations between drinking habits and these two cancers, but the number of deaths from liver cancer was still small. Not particular patterns were observed for cancers of the large bowel and lung.

Adult↗
PubMed1985

Placental plasminogen activator activity in pre-eclampsia.

Plasminogen activator is one of the principal enzymes involved in the fibrinolytic system. The plasminogen activator activity in placental tissue was examined using a chromogenic substrate in 9 patients with pre-eclampsia and in 9 women with uncomplicated pregnancy, who were delivered between 37 and 42 weeks of gestation. In the patients with pre-eclampsia, the plasminogen activator activity was significantly (P less than 0.05) decreased compared with that in the control group of normal pregnant women. The present findings suggest a decreased fibrinolytic activity in the placental tissue of pre-eclamptic patients, which is responsible for fibrin deposition in the placental tissue and may contribute to placental ischemia and insufficiency in pre-eclampsia.

Adult↗
PubMed1985

A case of eclampsia during the 18th week of gestation.

We report a rare case of eclampsia which occurred during the 18th gestational week in the absence of hydatidiform disease or Rh isoimmunization. In spite of extensive examinations during pregnancy and postpartum, we were unable to find any underlying disease, and the patient returned to being normotensive and non-proteinuric postpartum.

Adult↗
PubMed1985

Chemotaxis of macrophage in inflammation.

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.

Animals↗