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Biomedical subjects

T Yoshimura

Publications and source records attributed to T Yoshimura.

At least 667 records · Page 37Linked to original sources
PubMed1986

Anti-platelet action of an anti-allergic agent, N-(3',4'-dimethoxycinnamoyl)anthranilic acid (tranilast).

The effects of N-(3',4'-dimethoxycinnamoyl)anthranilic acid (Tranilast), a blocker for histamine release from mast cells, on rabbit blood platelet functions were investigated. Tranilast inhibited dose dependently both the release of a lysozomal enzyme, beta-N-acetylglucosaminidase, and aggregation of washed rabbit platelets stimulated by thrombin and collagen. The IC50 was suspected to be 164 +/- 50 microM. The data suggest that Tranilast may be used as an anti-platelet agent in addition to an anti-allergic one.

Acetylglucosaminidase↗
PubMed1986

Adrenoleukodystrophy and beta-galactosidase deficiency: patient and carrier.

A patient with adrenoleukodystrophy and his mother, a carrier, showed an elevated ratio of very long-chain fatty acids to long-chain fatty acids and decreased beta-galactosidase activity. Other lysosomal enzyme activities were normal except for the borderline level of arylsulfatase-A activity. However, the father and other patients with variant forms of adrenoleukodystrophy showed normal beta-galactosidase and other lysosomal enzyme activities.

Adrenoleukodystrophy↗
PubMed1986

Transient responses in cardiac function below, at, and above anaerobic threshold.

Exercise-induced alterations in cardiac function during graded cycling with submaximal and maximal intensities were studied in 13 trained and 13 untrained young men. Stroke volume (SV) and stroke index (SI) at rest and during submaximal and maximal exercise, determined by impedance cardiography, were consistently greater in the trained than in the less fit group. Training-induced bradycardia was evident in the trained group at rest and during submaximal exercise. Even when SV and SI were compared at the same absolute heart rate and left ventricular ejection time, those for the trained group were markedly greater than those for the untrained. SV for the untrained group was relatively diminished above the work rate corresponding to the anaerobic threshold. The difference in SV during exercise may be attributed to inadequate filling due to the smaller stretch of myocardial fibers in diastole and/or lesser systolic emptying of the left ventricle due to the reduced myocardial contractility in systole of untrained individuals.

Adult↗
PubMed1986

Ultrastructural study of the effect of calcium ionophore, A23187, on rat muscle.

The present study was undertaken to investigate changes in the muscle fiber when treated with calcium ionophore. Muscles treated with ionophore showed disruption of the plasma membrane of the muscle fiber, delta lesions, marked contraction of the myofibrills, and dissolution of Z lines and I bands. Black granules of calcium pyroantimonate were observed inside the plasma membrane in ionophore-treated muscle fibers without alteration of the other muscle organelles. The density of the intramembranous particles was less in muscle treated with calcium ionophore than in the control muscle. These results support the previous hypothesis that the increased concentration of intracellular calcium activates calcium-activated neutral protease and induces necrosis of the myofiber. The mechanism for the decrease in the density of intramembranous particles is unsolved. However, the disruption of the plasma membrane may not be a direct effect of calcium ionophore on it, but a secondary phenomenon which occurs after the calcium-induced necrosis of the muscle fibers.

Animals↗
PubMed1986

Vasopressor activity in incubated plasma of normal and hypertensive pregnant women.

The pressor activity generated in incubated plasma of nonpregnant, normal pregnant, and hypertensive pregnant women was measured by means of a sensitive bioassay technique. It was found that the plasma of normal pregnant women generated significantly higher amounts of active pressor principle than the plasma of nonpregnant women. The plasma of hypertensive pregnant women generated significantly lower amounts of active pressor principle than the plasma of normal pregnant women. Plasma obtained from the antecubital vein revealed no difference in pressor activity compared to plasma collected from the uterine vein at the time of cesarean section. These data suggest that active pressor principle is not involved in the pathogenesis of pregnancy-induced hypertension and that the pregnant uterus is not the source of active pressor principle.

Angiotensin II↗
PubMed1986

Effects of highly purified eicosapentaenoic acid on vascular reactivity to angiotensin II and norepinephrine in the rabbit.

There is disagreement about whether supplementation of the diet with fish oil, which is rich in eicosapentaenoic acid (EPA), lowers blood pressure. We gave highly purified EPA in a soft capsule (90% ethyl ester form of EPA; EPA-E), to female rabbits (100 mg/kg/day) for 4 weeks. Vascular response to vasoconstrictor agents was assessed serially by measuring the systolic blood pressure using a Grand-Rothschild capsule in the ear. There was no change in systolic blood pressure of rabbits treated with EPA-E, but rabbits given EPA-E for one week or longer were significantly less responsive to the pressor effects of angiotensin II than the controls. Responses to norepinephrine did not change. Rabbits given EPA-E for four weeks had significantly more EPA in the serum, but there were no differences in serum levels of triglycerides, total cholesterol, or high-density lipoprotein cholesterol. These results suggest that vascular responses to exogenous angiotensin II can be selectively depressed by short-term treatment with EPA-E in rabbits without changing systolic blood pressure.

Angiotensin II↗
PubMed1986

Galanin-induced hyperglycemia: effect on insulin and glucagon.

Synthetic galanin, infused at a rate of 4 micrograms/kg body weight/h for 30 min, elicited a mild but significant hyperglycemia in conscious dogs and a fall in plasma insulin. Pancreatic glucagon, epinephrine, norepinephrine, cortisol and growth hormone levels were not affected significantly. The mild hyperglycemic action of galanin seems to be due to an inhibition of insulin production. Thus galanin appears to be involved in glucose homeostasis.

Animals↗
PubMed1986

Region of cytochrome c interacting with yeast cytochrome b2: determination with singly modified carboxydinitrophenyl cytochromes c.

The association and reduction reactions of ten different 4-carboxy-2,6-dinitrophenyl (CDNP) horse heart cytochromes c, singly modified at lysines 8, 13, 27, 39, 60, 72, 73, 86, 87, and 99, with Saccharomyces cerevisiae cytochrome b2 were studied to determine the region of cytochrome c interacting with cytochrome b2. In the presence of higher ratios of free cytochrome c to cytochrome b2, native cytochrome c, and the CDNP-lysine 39, 60, and 99 derivatives associated with cytochrome b2 with a binding stoichiometry close to 2:1, while CDNP-cytochromes c modified at lysines 8, 13, 27, 72, 73, 86, and 87 formed only 1:1 complexes. In the presence of lower ratios of free cytochrome c, modifications of lysines 8, 27, 86, and 87 had more inhibitory effects on the association of cytochrome c with cytochrome b2 than modifications of lysines 13, 39, 60, 72, 73, and 99. This tendency was similar to that on removal of free cytochrome c, except in the case of CDNP-lysine 13 and 73 derivatives. The rate of reduction of cytochrome c by cytochrome b2 was decreased by carboxydinitrophenylation of lysines 8, 13, 27, 72, 73, 86, and 87. In contrast, the rate of reduction of cytochrome c was not affected by modifications of lysines 39, 60, and 99. Since lysines 8, 13, 27, 72, 73, 86, and 87 are located on the front surface and lysines 39, 60, and 99 on the back side, and since different effects of modifying lysine residues located on the front surface may be interpreted in terms of effects on the complementary interaction of cytochrome c and cytochrome b2, these results indicate that the region of cytochrome c interacting with cytochrome b2 is located on the front surface of the cytochrome c molecule containing the exposed heme edge.

Animals↗
PubMed1986

Purification and some properties of cytochrome c' from a strain of Achromobacter xylosoxidans.

Cytochrome c' was crystallized from Achromobacter xylosoxidans GIFU 543. The cytochrome was a basic protein and its molecular weight was 28,000. The pyridine ferrohemochrome showed absorption peaks at 415, 521, and 551 nm. The absorption spectra of the oxidized and reduced forms at neutral pH were almost the same as those of other cytochromes c' reported already. The reduced cytochrome c' reacted with CO and NO, and the NO complex showed a characteristic absorption spectrum. The midpoint redox potential of the hemoprotein was measured to be + 110 mV at pH 7.2.

Alcaligenes↗
PubMed1986

Light and electron microscopic study of mucoepidermoid tumor of clear cell type.

A rare type of mucoepidermoid tumor of hard palate was found in a 42-year-old man. By light microscopic examination, the nests of the tumor consisted almost entirely of clear cells and partly of epidermoid cells observed at the periphery of the nests. In addition, only a few isolated mucous cells were dispersed in sheets of the clear cells. Transition between the epidermoid cells and clear cells was apparent, characterized by a progressive clearing of the cytoplasm. It was shown by both the PAS reaction and removal by diastase digestion that the clear cytoplasm is due to the presence of significant amount of glycogen granules. By electron microscopic examination, adhesiveness of the epidermoid cells and the clear cells was characterized by numerous desmosomes. There were observed bundles of cytoplasmic tonofilaments and desmosome-tonofilament attachment complexes in these cells. There was a variable amount of amorphous lucent substance in the epidermoid and clear cells, particularly in the clear cells. It was assumed that glycogen is lost from cytoplasm during en bloc staining with uranyl acetate and the matrix of the glycogen areas appears as the amorphous feature.

Adult↗
PubMed1986

Decreased water and potassium content in erythrocytes in essential hypertension.

The water content in erythrocytes of subjects with borderline or established essential hypertension was measured by using gas-liquid chromatography and was found to be lower than that in normotensive controls (p less than 0.01). The water content in erythrocytes of normal controls (n = 14), borderline hypertensive subjects (n = 18), and established essential hypertensive subjects (n = 23) was (mean +/- SE) 71.0 +/- 0.2%, 69.9 +/- 0.2%, and 69.3 +/- 0.1% (vol/vol), respectively. A definite negative correlation was found between water content of erythrocytes and mean arterial pressure in normotensive and hypertensive subjects (n = 60, r = -0.59, p less than 0.001). Although there was no statistically significant between-group difference in the sodium content, the potassium content of erythrocytes from subjects with essential hypertension was significantly lower than that of normotensive controls (0.205 +/- 0.003 vs 0.222 +/- 0.004 mumol/mg dry red blood cells; p less than 0.01). There was no between-group correlation of sodium and water content in erythrocytes, but the potassium content correlated with the water content (n = 46, r = 0.49, p less than 0.001).

Blood Pressure↗
PubMed1986

Myocardial structure in volume-overloaded hearts before and after valve replacement.

The purpose of this study was to evaluate the histological characteristics of left ventricular muscle in volume-overloaded hearts. A preoperative biopsy was obtained in 31 patients: 14 with mitral regurgitation, 14 with aortic regurgitation and 3 with mitral regurgitation and aortic regurgitation. Postoperative tissue samples were available in 15 patients. Histological findings were correlated with echocardiographic and angiographic data before (preop) and one year after (postop) operation. Myocardial cell diameter was correlated with both the end-diastolic (r = 0.77, p less than 0.01) and end-systolic (r = 0.78, p less than 0.01) dimensions of the left ventricle, but was inversely correlated with the end-diastolic wall thickness-to-radius (h/R) ratio (r = -0.71, p less than 0.01). Percent fibrosis increased proportionally to the diameter (r = 0.42, p less than 0.05). For one year after operation, echocardiographic left ventricular dimensions and angiographic left ventricular volumes were significantly reduced (p less than 0.05), but in some patients postoperative values remained greater than normal. With regard to left ventricular morphology, myocardial cell diameter and interstitial fibrosis decreased significantly after valve replacement (p less than 0.05). However, the myocardial fiber remained hypertrophied and interstitial fibrosis remained above normal after surgery. Thus, postoperative ventricular dilatation was dependent upon the degree of myocardial fiber hypertrophy and interstitial fibrosis.

Cardiomegaly↗
PubMed1986

Myosin light chain kinase and cyclic AMP-dependent protein kinase activities and calmodulin levels in placental and non-placental regions of the rabbit myometrium.

Myosin light chain kinase activity in the placental region of the rabbit myometrium on day 28 of gestation was 4.7 +/- 0.1 (mean +/- S.E.M.) nmol/min per mg protein, which was significantly higher than that (3.6 +/- 0.1 nmol/min per mg protein) in the non-placental region. The amount of calmodulin in the placental region was 4.2 +/- 0.1 micrograms/mg protein, which was significantly higher than that (3.2 +/- 0.1 micrograms/mg protein) in the non-placental region. In contrast, cyclic AMP-dependent protein kinase activities showed no difference between the two regions. These findings suggest that calcium- and calmodulin-dependent protein phosphorylation is activated mainly in the placental region, and uterine contractions can occur more strongly in this part than in the non-placental region. Such enzymatic phenomena may be related to the mechanism whereby the placenta separates from the myometrium after delivery of the fetus.

Animals↗
PubMed1986

[Clinical evaluation of specificity of serum CA125 as a tumor marker of ovarian carcinoma].

To evaluate whether elevated serum CA125 levels have specificity to ovarian malignancies, CA125 levels were measured in sera of 48 malignancies, 56 benign diseases and 40 healthy women. Furthermore serum CA125 levels were serially followed up in all the patients with positive serum CA125 levels (35 U/ml less than or equal to) to evaluate the correlation between serum CA125 levels and the response to treatment. Results obtained were as follows. A significantly higher positive rate (91%) of serum CA125 levels was observed in patients with ovarian malignancies than that (30%) in patients with other malignancies. Positive serum CA125 levels were also observed in patients with endometriosis, benign ovarian tumor, hydrosalpinx, uterine myoma and peritoneal tuberculosis. Serum CA125 levels in patients with malignancies depend on the volume of the solid part of the tumor irrespective of the tumor type. In patients with positive serum CA125 levels, rising or falling of the serum levels of this antigen correlated well with progression or regression of all kinds of diseases. These results suggested that a high positive rate of this antigen in patients with ovarian malignancies was not merely derived from the tumor specificity of this marker but partly from the fact that tumor sizes of ovarian malignancies were generally larger than those of other malignancies.

Adenocarcinoma↗