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Biomedical subjects

R Miyatake

Publications and source records attributed to R Miyatake.

At least 19 recordsLinked to original sources
PubMed2002

Identification of a novel variant of the human NR2B gene promoter region and its possible association with schizophrenia.

N-methyl-D-aspartate (NMDA) receptor dysfunction is involved in the pathogenesis of schizophrenia. We determined the nucleotide sequence of the 5'-upstream region of the human NMDA receptor 2B (NR2B) subunit gene and identified a novel T-200G variant located in one of the Sp1 binding sites. To investigate the effect of this variant on the transcriptional activity of the hNR2B gene, we performed gene reporter assays using PC12 pheochromocytoma cells transiently transfected with luciferase reporter plasmids. In the absence of nerve growth factor (NGF), luciferase activities did not significantly differ between the two alleles and the control plasmid. However, luciferase reporter activity of the T allele was significantly up-regulated compared to that of the G allele in the presence of NGF (P = 0.0013), indicating that this polymorphic site is a critical region for NR2B gene regulation through NGF-induced Sp1-binding. A case control study showed that the frequency of the G allele (P = 0.0164) was significantly higher in 100 schizophrenics than in 100 controls. These findings suggest that the T-200G variant causes dysfunction of NMDA receptors consisting of the NR2B subunit and may be involved in the development of schizophrenia. Replication studies of independent samples and family-based association studies are necessary to further evaluate the significance of our findings.

5' Untranslated Regions↗
PubMed2001

[A case of tumor-forming chronic pyelonephritis that was difficult to be differentiated from renal cell carcinoma].

We experienced a rare case of tumor-forming type of chronic pyelonephritis that could hardly be differentiated from renal cell carcinoma. A 62-year-old man was admitted to our department with right renal tumor which was discovered when he underwent examination for gastric cancer. Abdominal ultrasound sonography and computed tomography revealed a mass in the middle portion of the right kidney, measuring 3.8 x 3.5 cm in diameter, with irregular surface and isoechoic and isodense inner mass. Renal angiography demonstrated a hypervascular area in the middle portion. Radical nephrectomy and subtotal gastrectomy were performed under a tentative diagnosis of right renal cell carcinoma and early gastric cancer. The excised specimen macroscopically demonstrated a yellowish mass in the middle portion and microscopically revealed many lymphocytes and few neutrophils, macrophages or foam cells. The patient was diagnosed as tumor-forming type of chronic pyelonephritis. Such obvious inflammatory findings very rarely exist in the tumor-forming type of chronic pyelonephritis. Therefore, caution should be exercised in the differential diagnosis between this disease and renal cell carcinoma.

Carcinoma, Renal Cell↗
PubMed2001

[A case of intratubular germ cell tumor giving rise to seminoma in a subfertile man].

A 34-year-old man visited our hospital with the complaint of right scrotal swelling. Right high orchiectomy was performed under the diagnosis of testicular tumor. Pathological examination was seminoma, pT2pN0pM0 and 3 courses of chemotherapy (cisplatin, vinblastine, bleomycin) were performed. The patient had undergone testicular biopsy for infertility at another hospital 6 years before this visit. Re-examination of the biopsy specimen revealed a intratubular germ cell tumor. No evidence of recurrence or metastasis was found 2 years after surgery.

Adult↗
PubMed2001

Effects of isoproterenol and butylscopolamine on the friction between an artificial stone and the intraureteral wall in anesthetized rabbits.

PURPOSE: We evaluated the effects of the nonselective beta-adrenoceptor agonist isoproterenol and the nonselective muscarinic antagonist butylscopolamine on ureteral wall tension, namely friction between an artificial stone and the intraureteral wall, in anesthetized rabbits. MATERIALS AND METHODS: The relaxing effect of the drugs on the KCl induced tonic contraction was examined in isolated rabbit ureters. The effect of the drugs on the applied force needed for the artificial stone to pass at a constant speed through the ureter, called sliding force, was evaluated in anesthetized rabbits. RESULTS: In a concentration dependent manner isoproterenol but not butylscopolamine reduced the KCl induced contraction in isolated ureter (mean pD2 7.35 +/- 0.06). Intravenous administration of 1 and 10 microg./kg. isoproterenol significantly decreased the friction between the artificial stone and intraureteral wall in anesthetized rabbits with sliding force at 15 minutes after drug administration decreased by 54.5% and 63.6%, respectively. In contrast, 100 and 1,000 microg./kg. butylscopolamine intravenously had no evident effect on ureteral wall tension. CONCLUSIONS: Our results strongly suggest that ureteral smooth muscle relaxation by beta-adrenergic stimulation reduces ureteral wall tension, thereby, diminishing mechanical effects impeding the movement of a ureteral stone down the ureter.

Adrenergic beta-Agonists↗
PubMed2000

[Vesicovaginal fistula due to a vaginal foreign body: a case report].

An 18-year-old female consulted a clinic complaining of pollakisuria and urinary incontinence. She was referred to our department for operation under the diagnosis of vesicovaginal fistula due to a vaginal foreign body confirmed by intravenous pyelography and cystoscopic examination. About 7 months earlier, she inserted a hair spray can into the vagina but could not remove its cap. The vaginal foreign body was transvaginally removed. After 2 months, transabdominal repair of the vesicovaginal fistula was performed. After operation, dysuria and urinary incontinence were not observed. Few cases of vesicovaginal fistula due to a foreign body in the vagina have been reported, and there have been only 6 reported cases in Japan including ours.

Adolescent↗
PubMed2000

[A case of testicular tumor in a patient with Down's syndrome: a case report].

A 40-year-old man with Down's syndrome was admitted to our hospital for complaint of painless, swollen right scrotum. Computed tomography revealed a right testicular tumor and mass of iliac fossa. Right high orchiectomy and extirpation of mass were performed. Histological diagnosis of right testicular tumor was seminoma and the mass was an external iliac lymph node metastasis of seminoma. After operation, radiation therapy was performed.

Adult↗
PubMed2000

Existence of a beta3-adrenoceptro and its functional role in the human ureter.

PURPOSE: We tried to determine the beta-adrenoceptor (AR) subtypes distributed in the human ureter and to clarify their functional role in ureteral relaxation. MATERIALS AND METHODS: 1) Effects of beta-AR agonists on either spontaneous or KCl-induced contractions of the human ureter and the antagonism by beta-AR antagonists on isoprenaline (a non-selective beta-AR agonist)-induced effects were evaluated in vitro. 2) Displacement by beta-AR antagonists of [3H]-dihydroalprenolol binding to a membrane preparation derived from human ureteral smooth muscle was evaluated. 3) A reverse transcription polymerase chain reaction assay was performed to determine the expression of the mRNA for beta1-, beta2- and beta3-ARs in human ureteral smooth muscle. RESULTS: 1) Isoprenaline and procaterol (a beta2-AR agonist) concentration-dependently suppressed both spontaneous and KCl-induced contractions of the human ureter. The beta3-AR agonists, CGP-12177A and CL-316243, also suppressed these ureteral contractions, but dobutamine (a beta1-AR agonist) had little relaxing effect. The rank order of relaxing potency for the catecholamines was isoprenaline > adrenaline > noradrenaline. ICI-118,551 (a beta2-AR antagonist) only partially antagonized the isoprenaline-induced relaxation. 2) Propranolol (a non-selective beta-AR antagonist) and ICI-118,551 concentration-dependently displaced [3H]-dihydroalprenolol binding to the membrane with Ki values of 1.5 x 10-9 M and 6.3 x 10-9 M, respectively, while metoprolol (a beta1-AR antagonist) was less effective in this assay. 3) beta1-, beta2- and beta3-AR mRNAs were all expressed in human ureteral smooth muscle. CONCLUSION: The present results provide the first evidence that the beta3-AR subtype is distributed in human ureteral smooth muscle and that it, and beta2-AR, mediate the ureteral relaxation induced by adrenergic stimulation.

Adult↗
PubMed1999

[A case of pedunculated hepatoma suspected of adrenal tumor].

A case of pedunculated hepatoma which was preoperatively diagnosed as non-functioning adrenal tumor is reported. A 48-year-old man presented to our hospital for further examination of remittent fever and leg edema. Abdominal ultrasonography, computed tomographic scan and magnetic resonance imaging showed a right suprarenal mass, its continuity of liver was uncertain. Tumor vessels were visualized on selective right adrenal arteriography and right adrenal function and serum alpha-fetoprotein were normal. Preoperative diagnosis was non-functioning right adrenal tumor. On operation, the dissection between the tumor and the inferior part of liver was easy. Pathological diagnosis was hepatocellular carcinoma with sarcomatous change. Difficulty of preoperative diagnosis of pedunculated hepatoma is discussed.

Adrenal Gland Neoplasms↗
PubMed1999

[An experience of indwelling of a urethral stent (Urolume Wallstent) for urethral stricture accompanying pelvic fracture in a young man].

The patient was a 15-year-old boy, who sustained pelvic fracture and complete disruption of the urethra in a traffic accident. The previous doctor performed two-staged treatment for complete disruption of the urethra, which ended in postoperative urethral stricture. We performed two sessions of endoscopic operations and a pull-through procedure, but the procedures were not effective. Five years later, a urethral stent was indwelt. Urolume Wallstent of AMS, Co, Ltd. was used as the urethral stent. At 4 months, the stent started to be enveloped in the urethral epithelia and no complications have been found in particular. However, detention of a permanent-type stent in a young man such as ours remains a controversial issue and long-term follow-up is needed.

Accidents, Traffic↗
PubMed1997

No linkage of the cytochrome P-450IIE1 (CYP2E1) C1/C2 polymorphism to schizophrenia.

We investigated, using PCR-SSCP analysis, the relationship between schizophrenia and the polymorphism of d-benzphetamine N-demethylase (cytochrome P-450j or CYP2E1), which metabolizes psychotropic substances such as d-benzphetamine and alcohols. Among 41 patients with schizophrenia, no statistically significant change in the frequency of the mutant (C2) allele relative to in controls was found, and no novel structural mutation in the CYP2E1 gene, which would be expected to alter the CYP2E1 protein, was found. This could be explained by no linkage of the CYP2E1 gene (mutations in the exon 1-9, and C1/C2 polymorphism) to schizophrenia.

Adult↗
PubMed1996

Tissue-specific alternative splicing of mouse brain type ryanodine receptor/calcium release channel mRNA.

We detected alternative splicing of the mouse brain type ryanodine receptor (RyR3) mRNA. The splicing variant was located in the transmembrane segment. The non-splicing type (RyR3-II) included a stretch of 341 bp, and that of the 13th codon was stop codon TAA. Reverse transcription-polymerase chain reaction (RT-PCR) analysis shows that RyR3-II mRNA was expressed in various peripheral tissues and brain at all developmental stages. However, interestingly, the splicing type (RyR3-I) mRNA was detected only in the cerebrum. These findings suggest that the splicing variants RyR3-I and RyR3-II may generate functional differences of RyR3 in a tissue-specific manner.

Aging↗
PubMed1996

No association between the neuroleptic malignant syndrome and mutations in the RYR1 gene associated malignant hyperthermia.

The neuroleptic malignant syndrome (NMS) is a drug-induced disease caused by neuroleptics, but the pathogenesis of NMS is unknown. Since NMS is similar to malignant hyperthermia (MH) in clinical features and treatment, 6 mutations in the skeletal muscle ryanodine receptor (RYR1) gene, which were associated with MH, were investigated in unrelated NMS patients by single-strand conformation polymorphism analysis (SSCP). As a result, MH-susceptible RYR1 mutations were not detected in our NMS patients. A single base substitution, C7278T, was detected in one patient whose serum CPK level was repetitively elevated, but his other major symptoms did not fulfil the clinical criteria for NMS. Our results do not support the association between the neuroleptic malignant syndrome and mutations in the RYR1 gene associated with malignant hyperthermia.

Adult↗
PubMed1996

Characteristics of Japanese alcoholics with the atypical aldehyde dehydrogenase 2*2. I. A comparison of the genotypes of ALDH2, ADH2, ADH3, and cytochrome P-4502E1 between alcoholics and nonalcoholics.

We examined the genotypes of the aldehyde dehydrogenase (ALDH)-2, alcohol dehydrogenase (ADH)-2, ADH3, and P-4502E1 loci of 53 alcoholics and 97 nonalcoholics. All of the subjects fulfilled the DSM-III-R criteria for alcohol dependence. The control group consisted of 97 subjects who were either hospital staff or students. We also compared the frequencies of homozygous ALDH2*1/1 and heterozygous ALDH2*1/2 genotypes in alcoholics. Our study revealed differences in the allelic frequencies of the ALDH2, ADH2, and ADH3 loci between alcoholics and nonalcoholics. For alcoholics with both homozygous ALDH2*1/1 and heterozygous ALDH2*1/2 genotypes, it was found that ADH2 and ADH3 played important rates. Alcoholics with the heterozygous ALDH2*1/2 genotype showed a significantly higher frequency of ADH2*1/1 than ones with the homozygous ALDH2*1/1 genotype. We assume ADH2*1 plays an important role in the development of alcoholism in alcoholics with the heterozygous ALDH2*1/2 genotype.

Adult↗
PubMed1996

Haloperidol inhibits neuronal nitric oxide synthase activity by preventing electron transfer.

The effect of a neuroleptic, haloperidol (HP), on nitric oxide formation catalyzed by neuronal nitric oxide synthase (n-NOS) in the porcine brain was investigated. HP inhibited n-NOS activity noncompetitively versus L-arginine as a substrate, decreasing the maximal velocity (Ki value for HP = 31 microM). HP also inhibited the CaM-dependent NADPH consumption by n-NOS (IC50 = 221 microM). These data demonstrate the possibility that HP may mediate some neuronal functions through inhibiting NO release by preventing either the electron transfer through n-NOS or the formation of the activated reduced species of oxygen necessary for the formation of citrulline. And an interaction of HP with CaM may possibly affect the consumption of NADPH and n-NOS enzyme activity.

Animals↗