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R Miyatake

Publications and source records attributed to R Miyatake.

35 records · Page 2Linked to original sources
PubMed1996

[Urodynamic evaluation of alpha-1 blocker tamsulosin on benign prostatic hyperplasia using pressure-flow study].

BACKGROUND: In order to evaluate the precise effect of alpha-1 blocker on benign prostatic hyperplasia, symptomatic and urodynamic parameters were compared between before and after 4 week administration of tamsulosin hydrochloride (0.2 mg/day) on 18 patients with untreated benign prostatic hyperplasia. METHODS: Symptoms were scored with international prostate symptom score (I-PSS) and urodynamic parameters were measured with pressure-flow study. RESULTS: The total score of I-PSS decreased significantly although the peak urinary flow rates, average flow rates or post-void residuals did not show a significant improvement after the treatment. On the other hand, the statistical analysis of pressure-flow studies revealed a significant decrease of vesical pressure at opening, at peak flow and at end of voiding after the treatment. In one patient, in whom the voided volume and urinary flow rate kept the same level throughout the treatment course, the total energy expelled from the bladder was calculated with the formula given as W = integral (pQ)dt. Both the detrusor work and vesical work (sum of detrusor contraction and abdominal straining) showed a marked decrease after the treatment. CONCLUSIONS: It is suggested that alpha-1 blocker relieves overload of the detrusor and improves symptoms by reducing the energy demands for bladder emptying, even in case the flow rate does not improve. The urodynamic procedure including pressure flow study is a useful means for not only diagnosing bladder outflow obstruction but also assessing overload or impaired contractility of the detrusor.

Adrenergic alpha-Antagonists↗
PubMed1996

[The ethanol elimination pharmacokinetics--the effects of genotypes of ALDH2 and CYP2E1 on the ethanol metabolism].

The effects of the genotypes of CYP2E1, ALDH2, ADH upon the blood ethanol and acetaldehyde levels were investigated. The predicting 95% confidence bounds determined on regression analysis of the data suggested that after venous injection of ethanol, the blood ethanol and acetaldehyde concentrations in a volunteer normal homozygous for ALDH2 (ALDH2*1/1) were significantly lower than that heterozygous (ALDH2*1/2). And the blood ethanol and acetaldehyde concentrations in a volunteer with C2 allele (C1/C2) were significantly lower than that in (C1/1). However, there were no significant differences in the blood ethanol and acetaldehyde concentrations between volunteers with ADH2*1/1 and ALDH2*1/2. It is possible that the ALDH2*1 and C2 alleles may correspond to the lower blood ethanol and acetaldehyde concentrations after intravenous administrations of 0.2 g /kg of ethanol.

Adult↗
PubMed1995

CYP2E1 genotypes and serum LAP in Japanese alcoholics.

The genotypes of the ALDH2 and CYP2E1 loci of Japanese alcoholic patients were determined to investigate the susceptibility to alcoholic liver injury. In alcoholics with a liver-function disorder, a significant association was observed between the genotypes of the CYP2E1 loci and the serum level of a liver-derived enzyme, LAP. However, there was no significant association between the ALDH2 genotypes and liver dysfunction.

Alcoholism↗
PubMed1995

The drug-drug interaction effects of haloperidol on plasma carbamazepine levels.

The metabolic interaction between carbamazepine (CBZ) and haloperidol (HP) was studied in Japanese schizophrenic patients treated with HP but not with CBZ and with both CBZ and HP. The serum CBZ concentrations in patients treated without HP were significantly decreased (p < 0.05), on average approximately 40%, as compared to those in patients treated with both CBZ and HP, whereas the serum HP concentrations in patients treated with both HP and CBZ were significantly decreased (p < 0.05), as compared to those in patients treated with HP but not with CBZ. The effect of HP, which prevents the serum CBZ level from decreasing, was shown in this study.

Anticonvulsants↗
PubMed1995

[How does thermotherapy effectively work on benign prostatic hyperplasia--an experimental study].

Isometric contractile force of rabbit prostatic tissue in response to electric field stimulation (EFS), KCl, and phenylephrine were measured at incubation temperature of 37 degrees C, before and after thermal exposure to 42 degrees C, 45 degrees C, 48 degrees C and 50 degrees C for 30 minutes. The contractile force in response to EFS decreased after thermal exposure above 45 degrees C, and the contractile force in response to KCL or phenylephrine decreased after thermal exposure above 48 degrees C. All the contractile response abolished after thermal exposure to 50 degrees C. The results indicate that the nerve is more hear-sensitive than the smooth muscle in the prostate. Histological examination revealed shrinkage of cell body and dark staining of nuclear chromatin of the smooth muscle cells after thermal exposure above 48 degrees C. The same histological change of the smooth muscle as well as degenerative change of the nerve cells was observed on the prostate 3-7 months after clinical thermotherapy. From these results, it is suggested that clinical effect of thermotherapy is brought about from both neural and muscular damage of the prostate. Since the least temperature to cause an irreversible tissue damage ranges from 48 degrees C through 50 degrees C, we believe it is ideal to heat the prostate around 50 degrees C to obtain a good clinical effect of thermotherapy on benign prostatic hyperplasia as a minimum invasive treatment.

Aged↗
PubMed1995

[The adrenoceptor and calcitionin-gene related peptide receptor in the striated urethral sphincter in male rabbit].

BACKGROUND: The objective of this study is to analyze the adrenoceptor and calcitonin-gene related peptide receptor in the isolated striated urethral sphincter from a male rabbit. METHODS: The striated urethral sphincter preparations were suspended in 2ml tissue chamber filled with Krebs Ringer solution, and the changes of isometric twitch contraction induced by electrical field stimulation (EFS-contraction) were recorded in the presence of 3-isobutyl-1-methyl-xanthine (IBMX, 10(-5) M). RESULTS: The EFS-contraction was almost completely attenuated by tetrodotoxin (TTX, 10(7) M), vecronium (10(-4) M) and suxamethonium (10(-4) M). Norepinephrine (NE, 10(-8) M-10(-4) M) did not affect the EFS-contraction, but increased the tonic contraction in a dose-dependent manner. The tonic contractions induced by NE was significantly blocked by phentolamine (10(-6) M). Clonidine (10(-7) M), yohimbin (10(-7) M) and propranolol (10(-9) M-10(-6) M) did not affect the EFS-contraction. Isoproterenol (10(-9) M-10(-6) M) did not reduce the carbachol (10(-5) M) induced tonic contraction. Calcitonin-gene related paptide (CGRP, 10(-7) M-3 x 10(-6) M) did not affect the EFS-contraction and did not increase the tonic contraction. CONCLUSION: These results suggested that alpha 1-adrenoceptors of the striated urethral sphincter play a role to modulate the resting tension level, but alpha 2-adrenoceptors, beta-adrenoceptors and CGRP receptors play no role in this regard.

Adrenergic alpha-Antagonists↗
PubMed1995

[The ethanol elimination pharmacokinetics--the effects of genotypes of ALDH2 and CYP2E1 on the ethanol metabolism].

The effect of CYP2E1 upon the blood ethanol level was investigated. Blood ethanol concentrations in 4 volunteers whose ADH 2, ADH 3 and ALDH 2 genotypes were identical, were determined after intravenous administrations of 0.20 g/kg of ethanol by gas chromatography. The predicting 95% confidence bounds determined on regression analysis of these data suggested that after venous injection of ethanol, the blood ethanol concentration in a volunteer normal homozygous for CYP2E1 (C1/C1) is higher than that heterozygous (C1/C2). And beta 60 (the blood ethanol concentration-time curve) of the subject heterozygous for CYP2E1 (C1/C2) was higher than that normal homozygous (C1/C1). It is possible that the C2 allele corresponding to the higher CYP2E1 activity may affect the ethanol metabolism.

Aldehyde Dehydrogenase↗
PubMed1995

[Association between alcoholics and the genotypes of ALDH2, ADH2, ADH3 as well as P-4502E1].

We examined the genotypes of ALDH2, ADH2, ADH3 and P-4502E1 loci of alcoholics and nonalcoholics. Also we compared the frequencies of the homozygous ALDH2*1/1 genotype and heterozygous ALDH2*1/2 genotypes in alcoholics. Our study reported differences in the allelic frequencies of ALDH2, ADH2 and ADH3 loci between alcoholics and nonalcoholics. For alcoholics, it was indicated that ADH2 and ADH3 plays an important role for alcoholism. For genotypes of P-4502E1, no significant difference was observed between alcoholics and nonalcoholics. Alcoholics with the heterozygous ALDH2*1/2 genotype had significantly higher frequency of the ADH2*1 than that of alcoholics with ALDH2*1/1 genotype. Concerning the alcoholics with the heterozygous ALDH2*1/2 genotype, we assumed that ADH2*1 plays a role for the development of alcoholism.

Alcohol Dehydrogenase↗
PubMed1994

[The genotype of CYP2E1 and liver-derived serum enzymes].

We determined the genotypes of the CYP2E1 loci of Japanese alcoholics with or without liver dysfunction to investigate the relationship between CYP2E1 and the susceptibility to alcoholic liver-injury. In the alcoholics (DSM-III-R) with a liver dysfunction, there was a significant relationship between the serum concentration of a liver-derived serum enzyme LAP and the C2 allele of CYP2E1.

Alanine Transaminase↗
PubMed1994

[Blood ethanol levels and the CTP2E1 C2 allele].

The effect of CYP2E1 upon the blood ethanol level was investigated. Blood ethanol concentrations in 2 volunteers whose ADH2, ADH3 and ALDH2 genotypes were identical, were determined after intravenous administrations of 0.15 g/kg of ethanol by gas chromatography. beta 60 (0.28 mg/ml/hr) of the blood ethanol concentration-time curve in one with the CYP2E1 C2 allele was higher than that (0.25 mg/ml/hr) in the other with no C2 allele. It is possible that the C2 allele may correspond to the higher CYP2E1 activity of ethanol metabolism.

Aldehyde Dehydrogenase↗
PubMed1994

[A characteristic of alcoholics with the atypical aldehyde dehydrogenase (ALDH2(2)--a relationship to other alcohol metabolizing enzymes].

The series were composed of 59 alcoholics. All the subjects fulfilled the DSM-III-R criteria for alcohol dependency. We investigated the genotype at ALDH2. 6 patients were heterozygous ALDH2(1)/ALDH2(2). We determined the genotypes at ADH2, ADH3 and P-4502E1 about 6 patients. 5 patients had ADH2(1)/ADH2(1) allele. 2 patients had P-450E1*C2. We found a genetic characteristic about alcoholics with the heterozygous ALDH2(1)/ALDH2(2) allele.

Alcohol Dehydrogenase↗
PubMed1994

[Relationship between alcoholism and genotypes of acetaldehyde-metabolizing enzymes].

The genotypes of the CYP2E1 and ALDH2 loci in alcoholic and non-alcoholic (healthy) Japanese were investigated to examine the relationship between the polymorphisms of CYP2E1 (C1/C2) and ALDH2 (ALDH2*1/ALDH2*2), and the susceptibility to alcoholism. There was no significant difference in C2 gene frequency between alcoholics (0.20) and non-alcoholics (0.19), while there was a significant difference in ALDH2 allele frequency, suggesting that the C2 allele of CYP2E1 may have nothing to the risk of developing alcoholism in Japanese, whereas the ALDH2*1 allele may influence drinking behavior and the development of alcoholism.

Alcoholism↗