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Biomedical subjects

Y Ohno

Publications and source records attributed to Y Ohno.

At least 487 records · Page 27Linked to original sources
PubMed1989

Case-control study of prostatic cancer in Kyoto, Japan: demographic and some lifestyle risk factors.

Demographic risk factors for prostatic cancer were examined in a case-control study of 100 triplets of prostatic cancer patients and age-, hospital-, and admission date-matched control series of benign prostatic hyperplasia (BPH) patients and general hospital patients. A higher risk of prostatic cancer was associated with the following factors: 1) long-term occupation in transport or communication (relative risk [RR] = 4.92, 95% confidence interval [CI]: 1.18-20.5) as compared with hospital controls; 2) the wife having a lower educational level (RR = 1.88, 95%CI: 1.02-3.45) as compared with hospital controls; 3) no past episode of hypertension as compared with BPH controls (RR = 2.30, 95%CI: 1.27-4.15); 4) having several sisters (more than four) as compared with both BPH and hospital controls (RR = 3.82, 95%CI: 1.35-10.8 and RR = 2.94, 95%CI: 1.08-8.03 respectively); 5) dense body hair as compared with hospital controls (RR = 4.28, 95%CI: 1.19-15.4). No significant links were found with blood type, daily drug use, head hair, skin color, body type, smoking habits, religion, body weight, and mental characteristics.

Aged↗
PubMed1989

Selective segmental hepatic necrosis produced by the Shwartzman mechanism in rabbits.

In this study, a new experimental model for hepatic necrosis is presented using rabbits, and E. coli endotoxin as the Shwartzman reagent. A segment of the liver was chosen as a target site for the univisceral Shwartzman reaction. Endotoxin-Lipiodol emulsion was used as a preparative injection via the portal venous branch into the target segment by direct puncture. Provocation was made by an intravenous injection of endotoxin 24 h later. A marked and sharply demarcated necrotic area was produced selectively in the target segment; specific changes were not seen in other lobes of the liver or other parts of the body. This model, strongly enhanced by using Lipiodol, seems to be a subtype of the univisceral Shwartzman reaction of the liver.

Animals↗
PubMed1989

Serum succinyltrialanine p-nitroanilide-hydrolytic activity in workers occupationally exposed to lead.

The relationship between blood lead concentration and serum succinyltrialanine p-nitroanilide-hydrolytic (STN) activity was investigated in 74 workers occupationally exposed to lead and in 28 non-exposed workers. Exposure to lead was observed during transfer-printing processes in which paints or paint powders containing 20-50% lead were used. The mean lead concentration was 0.49 mg/m3 (0.12-1.43 mg/m3) in the working environment and 1.42 mg/m3 (0.21-4.34 mg/m3) in workers involved in printing processes. Serum STN activity became lower with increasing concentrations of blood lead (PbB) in non-exposed workers (controls). In lead-exposed workers, the activity decreased with increasing concentrations of PbB of 2.0 mumol/l and more, but increased when less than 1.9 mumol/l. Among lead-exposed workers with high PbB concentrations and/or with hepatic dysfunction, the STN/PbB ratio was distributed above the regression line obtained from the controls. The present investigation suggests that serum STN activity decreases in those highly exposed to lead. Enzymes such as elastase, which hydrolyzes succinyltrialanine p-nitroanilide and additionally is not inhibited by lead, may possibly be induced among lead workers when liver function is impaired.

Adult↗
PubMed1989

Peripheral-type benzodiazepine receptors are involved in the regulation of cholesterol side chain cleavage in adrenocortical mitochondria.

In an attempt to elucidate the physiological relevance of the peripheral type of benzodiazepine receptor in adrenocortical mitochondria, we examined the effect of three different benzodiazepines (diazepam, Ro5-4864, and chlordiazepoxide) on the conversion of cholesterol to pregnenolone, the rate-limiting step in steroidogenesis, by using cholesterol-loaded mitochondria from bovine adrenal zona fasciculata. These benzodiazepines, except chlordiazepoxide, caused a dose-dependent stimulation of the cholesterol side chain cleavage in the mitochondria. The stimulatory effect of Ro5-4864 was approximately 10 times more potent than that of diazepam. No inhibitory effect of YM-684 (Ro15-1788), a potent antagonist to central-type benzodiazepine receptors, was observed in the stimulation induced by diazepam and Ro5-4864. Both external calcium ion and voltage-dependent calcium channel blocker, (+)-PN200-110, were without effect on the diazepam-induced steroidogenesis. By contrast, pretreatment of mitochondria with digitonin abolished the stimulatory effect of diazepam on the mitochondrial steroidogenesis. The present results indicate that the peripheral-type benzodiazepine receptor of adrenocortical mitochondria plays an essential role in regulating cholesterol side chain cleavage without any change of calcium channels.

Adrenal Cortex↗
PubMed1989

Multi-step carcinogenesis model for adult T-cell leukemia.

The age-specific occurrence of adult T-cell leukemia (ATL) was analyzed using 357 cases collected during nationwide surveys carried out between 1982 and 1985 in Japan. A simple Weibull distribution function fitted well as a model. The mode of ATL onset was log-linear in this model and the curves for males and females overlapped completely. The presence of age-dependent accumulation of leukemogenic events within human T-cell leukemia virus type 1-immortalized T cells was suggested prior to the development of ATL, and the approximate number of independent leukemogenic events in ATL is estimated to be five. This stochastic analysis supported a multi-step carcinogenesis as an appropriate model for ATL.

Adult↗
PubMed1989

The hypotensive effect and antifungal activity of 3,3'-dihydroxy-alpha,beta-diethyldiphenylethane.

3,3'-Dihydroxy-alpha,beta-diethyldiphenylethane (I), an isomer of hexestrol (II), was found to have a strong hypotensive effect on rats and antifungal activity against some pathogenic fungi. The hypotensive effect of I (-100.0 +/- 21.0 mmHg, 10 mg/kg, i.v.) was stronger than that of II (-40.0 +/- 2.60 mmHg, i.v.). Unlike II and other oxystilbene-related compounds already tested, I showed prolonged hypotensive action at the dose of 10 mg/kg, and the blood pressure was not restored to the original level within 20 min. I also showed antifungal activity against all fungi tested (minimal inhibitory concentration: 10-120 micrograms/ml). It should be emphasized that by shifting the phenolic hydroxyl group to m-position, the biological activities were greatly increased.

Animals↗
PubMed1989

Induction of cytochrome P-450c and P-450d by metyrapone in the primary culture of rat hepatocytes.

The effects of metyrapone on qualitative changes in cytochrome P-450-dependent drug metabolizing activities in primary cultures of rat hepatocytes were investigated. Metyrapone apparently increased benzo(a)pyrene hydroxylation and maintained both ethoxycoumarin-O-deethylation and propoxycoumarin-O-depropylation, whereas it had little effect on methoxycoumarin-O-demethylation. Furthermore, P-450d (high spin type of P-448) as well as P-450c (low spin type of P-448) were induced by metyrapone, while P-450b and P-450e were not. In conclusion, metyrapone act as a 3-methylcholanthrene-like inducer in the primary cultures of rat hepatocytes.

Animals↗
PubMed1989

Diazepam potentiates the corticoidogenic response of bovine adrenal fasciculata cells to dibutyryl cyclic AMP.

To provide a possible role of peripheral type benzodiazepine receptors in the regulation of glucocorticoid biosynthesis. We have examined the effect of diazepam on the corticoidogenic response to dibutyryl cyclic AMP in isolated bovine adrenal fasciculata cells. Diazepam alone (up to 100 microM) had no effect on the corticoidogenesis. Diazepam caused a dose-dependent potentiation of dibutyryl cyclic AMP-induced corticoidogenesis. However, diazepam had no effect on the corticoidogenic response to ACTH and a high concentration of KCl. The potentiating effect by diazepam was clearly detected after 90 min-incubation, and it was blocked by YM-684 (diazepam antagonist) and ML-236B (cholesterol de novo synthesis inhibitor). Diazepam caused no significant decrease of intracellular content of cholesteryl esters during the corticoidogenic response to dibutyryl cyclic AMP. When the cells were incubated in the presence of (+)-PN200-110, a potent voltage-dependent Ca channel inhibitor, the potentiating effect by diazepam was not affected in spite of a significant inhibition of dibutyryl cyclic AMP-induced corticoidogenesis. These results indicate that the potentiating effect of diazepam on dibutyryl cyclic AMP-induced corticoidogenesis is due in part to the activation of the intracellular cholesterol supply system (cholesterol de novo synthesis) without any change of voltage-dependent Ca channels.

Adrenal Cortex↗
PubMed1989

[Bone inductive activity of hydroxyapatite-bone morphogenetic protein complex].

Bone morphogenetic protein (BMP) is known to be a protein which induces new bone at heterotopic sites. Purification of BMP has not been perfected, and obtaining large amounts of BMP is very difficult, so it seems better to use some carrier or frame material for BMP to work effectively. Various kinds of hydroxyapatite (HAP) have been used to repair periodontal osseous defects, but they do not have osteogenetic or osteoinductive properties. If osteoinductive proteins such as BMP could retain their biologic properties after being implanted into living tissue with HAP, it would be an advantage in repairing periodontal osseous defects. In this experiment, we prepared BMP-HAP complex and investigated its osteoinductive activity. BMP was extracted from bovine cortical bones in accordance with the Urist's procedure. The ability of this BMP to stimulate new bone growth was ensured by implantation in the muscle pouch of mice. HAP was synthesized by the wet method. The BMP-HAP complex was implanted in the muscle pouch of mice, and osteoinduction was examined 3, 7, 14, and 21 days after implantation to assess its osteo-inductive ability. New bone formation was studied by roentgenographic and histologic observation. In the BMP-HAP group, new bone formation was seen on the roentgenograms and new cartilage and bone were observed histologically in the tissue surrounding the apatite. In the HAP group, no new cartilage or bone formation was noted.

Alveolar Bone Loss↗
PubMed1989

[Fine structural observations of age changes in cementocytes of human permanent teeth].

Human cementum formation is a continuous process which occurs throughout life. Young cementocytes are situated near the periodontal membrane and old cementocytes towards the cementodentinal junction. Electron microscopic observations on 110 cementocytes of human permanent teeth were carried out to analyze the morphological and morphometric changes due to ageing. Cementocytes with ageing showed a rapid decrease in the number of the cell and a gradual decrease in the size of the cell, nucleus and cytoplasm. The location of the nucleus was changed from the periodontal side to the dentinal side and was hyperchromatic. Organelles showed a decrease in the size of the mitochondria, the rough-surfaced endoplasmic reticulum and the Golgi apparatus, meanwhile showing a gradual increase in the number of vacuoles and lysosomes. The cell death with ageing showed a rapid increase in number and their lacunae contained nuclear remnants, mitochondrial-like structures and fine fibrillar materials. Two distinct types of age changes were recognized: cytoplasmic swelling with scanty organelles and pronounced vacuoles, and cytoplasmic atrophy preserving the rough-surfaced endoplasmic reticulum in the narrowing cementum lacuna.

Aging↗
PubMed1989

Prevention of phencyclidine-induced depression of the segmental reflex by L-3,4-dihydroxyphenylalanine in the rat spinal cord in vitro.

The interaction between phencyclidine (PCP) and the catecholamine precursor L-3,4-dihydroxyphenylalanine (DOPA) was studied in the isolated spinal cord from neonatal rats. PCP decreased the magnitude of the dorsal-ventral reflex and enhanced frequency-dependent depression of the reflex in a concentration-dependent manner. Although DOPA and DL-threo-3,4-dihydroxyphenylserine (a direct precursor for norepinephrine) had no effect on the reflex by themselves, DOPA, but not DL-threo-3,4-dihydroxyphenylserine prevented the depression of the reflex response by PCP in a concentration-dependent manner. Inhibition of aromatic-L-amino-acid decarboxylase (EC 4.1.1.2A) by m-hydroxybenzylhydrazine markedly attenuated the action of DOPA in preventing the depression caused by PCP. The dopamine receptor antagonists haloperidol and chlorpromazine blocked the action of DOPA, but the alpha and beta adrenergic receptor antagonists phentolamine and timolol, respectively, did not. In addition, prior treatment of neonatal rats with 6-hydroxydopamine diminished the ability of DOPA to prevent the depressant effect of PCP whereas partially attenuating the depressant effect of PCP alone. These results suggest that DOPA attenuated PCP-induced depression of spinal cord transmission through its conversion to dopamine rather than norepinephrine.

Animals↗
PubMed1989

Prevention of limb ischemia in surgical patients by intra-aortic balloon pumping.

Intra-aortic balloon pumping (IABP) was recently performed during the perioperative period in seven patients in whom balloon insertion was difficult because of vascular complication. Prophylactic measures for the prevention of limb ischemia were taken when the balloon was inserted. These measures included (1) balloon insertion through the femoral artery and continuous infusion of heparin into the femoral artery in three patients, (2) balloon insertion through the left femoral artery and femoro-femoral arterial crossover bypass in two patients, and (3) balloon insertion through the left common iliac artery and axillo-femoral bypass on the same side in two patients. Most patients recovered satisfactorily without any evidence of ischemia of the limbs either clinically or in serum biochemistry examination. One patient died of prolonged cardiac failure.

Aged↗
PubMed1989

Distribution of Gm allotypes among the three populations of the Miyako Islands in Okinawa.

Serum samples from 738 unrelated individuals of three populations in the Miyako Islands were tested for twelve Gm allotypes to investigate the variability of phenotypes and haplotypes. Nine phenotypes observed in these populations as well as mainland Japanese could be explained by the presence of the four Gm haplotypes, ag, axg, ab3st, and afb1b3. A good agreement was obtained in the samples of each populations between the observed and expected frequencies on the basis of the Hardy-Weinberg equilibrium of phenotypes. These populations showed remarkable heterogeneities with one another on the basis of Gm haplotype frequency analysis. Moreover they exhibited no homogeneities with the Ryukyuans nor with the mainland Japanese. Homogeneity was found between the Ainu and the people in Ueno village but not in the other two locations. However, Gm xg haplotype, only detected in the Ainu, was not found in Ueno. These may imply a racial relationship between the Ainu and the inhabitants in Miyako in the remote past. However, there is no certainty that both of Ainu and the people in Ueno derived from the same origin, or that genetic drift due to endogamy in this village took place. The Gm phenotype and haplotype frequencies observed in Miyako show that they belong to the northern mongoloid group characterized by a high frequency of Gm ag and an extremely low frequency of Gm afb1b3. It is therefore reasonable to assume that they came from northern Asia as well as mainland Japanese.

Asian People↗
PubMed1989

[A statistical study on distribution patterns of plasma free amino acids].

We investigated the distribution patterns of 23 plasma free amino acids in 875 healthy adults (375 males and 500 females, aged from 30 to 50 years), which were obtained after an overnight fast, using three statistical parameters of MLL (Maximum Logarithmic Likelihood), square root of b1, b2, and selected their patterns from the three of ordinary normal, log-normal and square root-normal distributions. The distribution patterns of the majority of plasma free amino acids were found to be either log-normal or square root-normal, and occasionally ordinary normal. We also evaluated the reliability of our selection system by a simulation model of 100 sets of values for plasma free amino acids that were randomly determined by the parameters of original data. Good reliability was observed for some amino acids. Our selection system may be useful for comparing the present results with the future results that will be obtained by other methods.

Adult↗