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Biomedical subjects

M Murayama

Publications and source records attributed to M Murayama.

At least 127 records · Page 7Linked to original sources
PubMed1995

A 13-Mer peptide of a brain injury-derived protein supports neuronal survival and rescues neurons from injury caused by glutamate.

Neuronal survival is mediated by several kinds of proteins. Among these, neurotrophic factors play important roles in the nervous system by supporting neuronal activity and survival. It has been suggested recently that certain factors promote neuronal survival in the case of brain injury. To examine this possibility, we purified a novel neurotrophic factor from Gelfoam that was implanted at the site of injury caused in neonatal rats. During amino acid sequence analysis, we found that a fragmental peptide of this neurotrophic protein consisting of 13 amino acids showed neurotrophic activity. This 13-mer peptide promoted survival of septal cholinergic and mesencephalic dopaminergic neurons in culture and rescued hippocampal neurons from injury caused by glutamate in culture. This peptide rescued neurons from cell death caused by glutamate, even when added 4.5 h after glutamate exposure.

Amino Acid Sequence↗
PubMed1995

Responses of plasma adrenocortical steroids to low dose ACTH in normal subjects.

OBJECTIVE: The standard ACTH test in clinical use employs a pharmacological dose of ACTH which assesses the maximum secretory capacity of the adrenal cortex. We have investigated the responses of plasma adrenocortical steroids including cortisol, aldosterone and dehydroepiandrosterone (DHEA) to physiological doses of ACTH (ACTH 1-24, tetracosactide, Cortrosyn) and determined the minimal dose which induces a response equivalent to that induced by a pharmacological dose of ACTH. DESIGN: Rapid ACTH tests at various physiological (0-1, 0.5, 1 and 5 micrograms) and standard pharmacological (250 micrograms) intravenous doses. SUBJECTS: Seven healthy normal volunteers. MEASUREMENTS: Plasma cortisol, aldosterone and DHEA were measured. Peak value and the increment from basal value were used as indices of responses. RESULTS: Each steroid responded to physiological doses of ACTH in a dose dependent manner. The minimum dose inducing an equivalent response to 250 micrograms ACTH was 0.5 micrograms for peak and incremental values in cortisol and DHEA, while that for aldosterone was 0.1 microgram. The time to peak for each steroid was delayed as the dose increased. Plasma aldosterone and DHEA peaked significantly earlier than plasma cortisol in 1-5 micrograms and 0.5-5-micrograms ACTH tests, respectively. CONCLUSIONS: These results suggest that the sensitivity of secretion to physiological doses of ACTH in descending order is aldosterone > DHEA = cortisol. When peak and incremental values are used, sufficient doses of ACTH are 0.1 microgram for plasma aldosterone and 0.5 microgram for plasma cortisol and DHEA in the rapid ACTH test.

Adrenal Cortex Hormones↗
PubMed1995

Alcohol and aldehyde dehydrogenase polymorphisms and the risk for alcoholism.

OBJECTIVE: The authors studied a large number of Japanese alcoholic patients and comparison subjects to establish the genotype frequencies of alcohol dehydrogenase-2 (ADH2) and mitochondrial aldehyde dehydrogenase (ALDH2) and to quantify the relative risk for alcoholism from the results. METHOD: The subjects were 655 alcoholic patients and 461 comparison subjects. ADH2 and ALDH2 were genotyped by the combination of polymerase chain reaction and hybridization methods. RESULTS: Active ALDH2 and usual ADH2 were significantly more frequent in the alcoholic patients. Inactive ALDH2 was not always associated with a low risk of alcoholism, and active ALDH2 was not always associated with high risk. In individuals with heterozygous inactive ALDH2 and usual ADH2, the odds ratio for alcoholism was high. CONCLUSIONS: The risk for alcoholism in Japanese has been accurately estimated on the basis of the genotype frequencies of ADH2 and ALDH2. Many Japanese may be protected from alcoholism by inactive ALDH2 and by higher frequencies of atypical ADH2.

Alcohol Dehydrogenase↗
PubMed1995

[Changes in plasma tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) by the interferon treatment for chronic hepatitis C].

To determine the effects of interferon (IFN) treatment for chronic hepatitis C on vascular endothelium, we measured the concentrations of tissue plasminogen activator (t-PA) and its inhibitor (PAI-1) in the plasma from patients before and after IFN treatment for 14 consecutive days. The plasma t-PA and PAI-1 levels were measured before and after treatment. The plasma t-PA level was significantly increased after IFN treatment (p < 0.01) but no significant difference in plasma PAI-1 level was observed before and after treatment. The ratio of t-PA/PAI-1 was significantly increased after IFN treatment (p < 0.05). These changes may be caused by the effect of IFN on endothelium, leading to an activation of the endothelium derived fibrinolysis factors. Increase in plasma t-PA concentration may induce hyperfibrinolysis which may be one of the causes of suborbital hemorrhage. Further study on the fibrinolysis pathway in the blood is necessary to elucidate the mechanisms of the many side effects observed during IFN treatment.

Adult↗
PubMed1995

[Effects of 5-fluorouracil in shrinking residual gastric cancer: a case report].

The patient was a 79-year-old man who underwent extensive gastrectomy and Billroth-II reconstruction for gastric ulcer in 1974. He complained of heartburn in November, 1992, and endoscopy for the residual stomach revealed IIb + IIa-like lesion mainly in the posterior wall of the anastomosed site, which was diagnosed as well differentiated adenocarcinoma. As the patient refused to be operated, 150 mg/day of 5-FU was administered. For 4 months before he decided to undergo operation, 12.9 g of 5-FU was administered in total. After rehospitalization, endoscopy of the residual stomach showed shrinkage of the lesion, and biopsy revealed no malignant findings. The pathological examination after total resection of the residual stomach showed atypism, but no evidence to support malignancy. He has continued to be well without sign of recurrence for 1 year since the operation. The administration of 5-FU is widely used as preoperative adjuvant chemotherapy. This case it is rare for 5-FU to cause the disappearance or falling off of malignant cells.

Adenocarcinoma↗
PubMed1995

A case of unique communication between blind-ending ectopic ureter and ipsilateral hemi-hematocolpometra in uterus didelphys.

Uterus didelphys with double vagina and hemi-vaginal atresia is a rare syndrome of congenital anomalies. A 17-year-old girl had a right blind-ending ectopic ureter, the proximal end of which communicated with the ipsilateral uterine cervix of uterus didelphys. The patient presented with vaginal urinary incontinence after incision of the vaginal wall for right hemi-hematocolpometra. Following various examinations, the ipsilateral kidney was found to be absent. The ectopic ureter and communicating duct were resected, and the fistula was closed. The genesis of malformation of the female genitalia and urinary tract resulting in such a unique communication is discussed. The importance of preoperative meticulous examinations, including cysto-genitography, pelvic magnetic resonance imaging and panendoscopy with the patient under anesthesia, is emphasized.

Abnormalities, Multiple↗
PubMed1995

[Effects of weight training on muscle strength and exercise capacity in patients after myocardial infarction].

The effect of combined aerobic and weight training on indexes of muscle strength and exercise capacity was investigated in 59 patients after myocardial infarction. Subjects were randomly assigned into three groups: group I performing combined aerobic and weight training (n = 22), group II performing ordinary aerobic training alone (n = 19) and group III not performing physical training (n = 18). Before and after the training, isokinetic knee extension strength was measured and cardiopulmonary exercise testing was performed. Physical training was prescribed for 8 weeks. Weight training of knee extensors was performed at 60% of 1 repetition maximum and aerobic training was prescribed at the heart rate of anaerobic threshold (AT) level. After 8 weeks, the increase of isokinetic knee extension strength was significantly greater in group I (26 +/- 14%) than group II (6 +/- 8%) and III (4 +/- 8%). Increases in peak VO2, exercise time, AT and peak O2 pulse were greater in groups I and II than group III. Furthermore, increase of exercise time was greater in group I (25 +/- 14%) than group II (16 +/- 9%). The rating of perceived exertion in submaximal exercise decreased significantly only for group I. In patients with myocardial infarction, combined aerobic and weight training is a more effective method for increasing muscle strength and exercise capacity than only ordinary aerobic training.

Aged↗
PubMed1994

Association of structural polymorphism of the dopamine D2 receptor gene and alcoholism.

To examine the possible association between three recently identified structural polymorphisms of the dopamine D2 receptor (DRD2) gene and alcoholism, we compared allele frequencies of these polymorphisms in 280 Japanese alcoholics and 289 normal controls. The results revealed that only one of three variants identified in white individuals existed in the alcoholic and control Japanese. The frequency of the Cys311 variant allele was significantly higher in alcoholics (.063) than in controls (.029). All of the subjects with the variant allele were heterozygous Ser311/Cys311. Patients with Cys311 allele had less severe symptoms of alcoholism than did those with homozygous Ser311, especially symptoms related to loss of control over drinking. The coprevalence of other psychiatric disorders including schizophrenia did not differ between the two patient groups. These results suggest that the D2/Cys311 variant is associated with some type of alcoholism in Japanese.

Age of Onset↗
PubMed1994

ACTH and phorbol ester stimulated redistribution of protein kinase C in human cortisol-producing adrenal adenoma.

We studied the steroidogenetic action and concomitant subcellular redistribution of protein kinase C (PKC) in cortisol hypersecreting adrenal adenoma cells obtained from two patients with Cushing's syndrome. Isolated adenoma cells were treated with 10(-9) M and 10(-6) M 12-O-tetradecanoyl phorbol-13-acetate (TPA) or 10(-6) M ACTH. Treatment of the isolated adenoma cells with TPA resulted in cortisol secretion equivalent to that with ACTH-treatment. Immunoblot analysis of PKC during treatment with ACTH or TPA showed that PKC beta translocated from cytosol to membrane. A small amount of PKC alpha, but not membrane-associated PKC alpha, was detectable in the cytosolic fraction. It appeared that TPA-induced cortisol secretion mimicked ACTH-induced cortisol secretion, and that PKC beta translocated from cytosol to membrane on stimulation by both ACTH and TPA. We suggested that ACTH-induced cortisol secretion in human cortisol hypersecreting adrenal adenoma is mediated by PKC beta activation.

Adenoma↗
PubMed1994

Pharmacokinetics of propranolol used for suppressing tachycardia in hyperthyroidism.

The aim of this study was to investigate the pharmacokinetics of propranolol in patients with hyperthyroidism, and its effect on heart rate (HR) using 24 hour-ECG monitoring. Subjects included 9 patients with hyperthyroidism (group H) and 9 euthyroid patients with hypertension selected as the control group (group C). All patients took propranolol at a dosage of 10 mg, 3 times a day for 7 days. Plasma propranolol concentrations were measured on the 7th day of its administration by the HPLC method. Twenty-four hour-ECG monitoring was recorded twice before and after treatment with propranolol. The mean reduction in the minimum HR was 10.7 +/- 3.6 (11.9 +/- 3.6%) in group H and 5.0 +/- 1.6 (9.5 +/- 3.0%) bpm in group C. That in the average HR was 12.2 +/- 3.7 (11.3 +/- 3.1%) in group H and 9.2 +/- 2.2 bpm (13.7 +/- 3.2%) in group C. That in the maximum HR was 16.9 +/- 5.2 (10.9 +/- 3.1%) in group H and 24.4 +/- 2.4 bpm (21.9 +/- 2.1%) in group C. The peak concentration of propranolol in plasma was 10.8 +/- 2.4 ng/ml in group H and 55.3 +/- 14.3 ng/ml in group C (p < 0.01). There was a linear correlation between the reduction in the hourly maximum heart rate and the peak plasma propranolol concentration in group H. Cardiovascular manifestations in hyperthyroid patients were related to sympathetic hypersensitivity and their improvement was not fully obtained by small doses of propranolol.

Adult↗
PubMed1994

Long term follow-up of Cushing's disease treated with reserpine and pituitary irradiation followed by subtotal adrenalectomy.

Subtotal adrenalectomy was given to 10 adult patients with Cushing's disease, concurrently with or following therapeutic regimen by long term reserpine administration and pituitary irradiation. In the present study, we describe long term follow-up results. Two patients died after the operation due to acute adrenal crisis and pneumonia, respectively. The other 8 patients achieved clinical and biochemical remissions and were followed for long term. Three patients relapsed 9, 14 or 17 years after achieving remission, two patients developed hypopituitarism 12 or 20 years after and one died of cerebral vascular accident at 64 years, 5 years after the remission. The remaining 2 patients maintained remission for 10 or 18 years, respectively. During the remission periods of 0.5 to 20 years with a mean of 10.1 +/- 6.7 years, 6 of 7 patients examined by 1 mg overnight dexamethasone test showed normal suppressibility of plasma cortisol. Provocative tests of plasma GH by l-arginine infusion and/or insulin-induced hypoglycemia were performed in 6 patients in the early remission period. All of 5 patients in the arginine infusion test and 3 of 5 in the insulin-induced hypoglycemia test showed normal responses. Furthermore, to facilitate prediction of long term response or failure to our therapeutic regimen, long term reserpine administration and pituitary irradiation, pretreatment clinical and biochemical characteristics were analyzed retrospectively in 3 divided groups; the present 10 patients treated with reserpine and pituitary irradiation followed by subtotal adrenalectomy, 11 patients achieving long term remission treated by our regimen alone, and 7 patients failed with our regimen alone. There were no significant factors predictive of response to our regimen. These findings suggest that subtotal adrenalectomy does not lead favorable outcome, however, reserpine administration shows usefulness to improve pituitary functions in treating Cushing's disease.

Adolescent↗