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Biomedical subjects

M Minami

Publications and source records attributed to M Minami.

At least 469 records · Page 26Linked to original sources
PubMed1991

Angiotensin II induced biphasic inositol 1,4,5-triphosphate response in rat vascular smooth muscle cells.

We examined angiotensin II induced changes of inositol 1,4,5-triphosphate (Ins(1,4,5)P3) in cultured vascular smooth muscle cells from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) using a specific protein binding assay system. We observed a rapid biphasic Ins(1,4,5)P3 response, which peaked at 5 s and at 30 s after angiotensin II stimulation. At every period of time the Ins(1,4,5)P3 level of SHR was 2- to 5-fold higher than that of WKY. Thus, the Ins(1,4,5)P3 specific assay revealed a complex Ins(1,4,5)P3 response after angiotensin II stimulation and suggested the need for further investigation of the Ins(1,4,5)P3 metabolism following agonist stimulation in vascular smooth muscle cells.

Angiotensin II↗
PubMed1991

Methamphetamine-induced expression of interleukin-1 beta mRNA in the rat hypothalamus.

The effect of methamphetamine on the expression of interleukin-1 beta (IL-1 beta) mRNA in the rat brain was investigated with Northern blot analysis. Methamphetamine (2-15 mg/kg, i.p.) caused a marked induction of IL-1 beta mRNA in the hypothalamus among the 8 brain regions examined, in a dose-dependent manner. The level of IL-1 beta mRNA reached a maximum at 1 h and rapidly declined within 2 h after the injection of 15 mg/kg. These results provide the first evidence that methamphetamine induces the expression of IL-1 beta mRNA in the hypothalamus, which may be partly involved in the production of central actions of this drug.

Animals↗
PubMed1991

Sequence-specific single-strand DNA-binding proteins that interact with the regulatory regions of wheat histone H3 and H4 genes.

We identified two novel DNA-binding proteins, ssDBP-1 and ssDBP-2, in wheat germ nuclear extract that interact with the proximal sequences of the promoter regions of the wheat histone H3 and H4 genes. Mobility shift and methylation interference assays have demonstrated that these factors specifically bind to the single-strand DNA which partially overlaps the hexamer and octamer cis-elements of the H3 promoter. Both proteins are distinguishable from HBP-1a and HBP-1b which specifically bind to the H3 hexamer sequence. These ssDNA-binding proteins are supposed to regulate the transcription of the wheat histone genes.

Base Sequence↗
PubMed1991

Effects of kainic acid on messenger RNA levels of IL-1 beta, IL-6, TNF alpha and LIF in the rat brain.

We examined the kainic acid-induced changes of mRNA levels of several cytokines such as IL-1 beta, IL-6, TNF alpha and LIF in the rat brain regions using semiquantitative RT-PCR method. IL-1 beta mRNA was markedly increased in the cerebral cortex (CC), thalamus (THL) and hypothalamus (HT) 2 h after the injection of kainic acid in a convulsive dose (12 mg/kg i.p.), and tended to decrease 4 h after the injection. IL-6 mRNA was weakly induced in the hippocampus (HPP) 2 h after the injection of kainic acid and was markedly increased in the CC, HPP, THL, and HT at 4 h. The level of TNF alpha mRNA was highly elevated in the CC, HPP, striatum (STR), THL and HT at 2 and 4 h after the injection. LIF mRNA apparently expressed in the CC and HPP of control rats and was increased in the CC, HPP and HT by the treatment with kainic acid. These results indicate that mRNAs of several cytokines are increased in various brain regions with different time-courses by kainic acid.

Animals↗
PubMed1991

Reduction of enzymatic activity of tyrosine hydroxylase by a heterocyclic amine, 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole (Trp-P-1), was due to reduced affinity to a cofactor biopterin.

A carcinogenic, food-derived heterocyclic amine, 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole (Trp-P-1) was found to reduce the enzymatic activity of tyrosine hydroxylase in clonal rat pheochromocytoma PC12h cells, by its supplement to the culture medium. The reduction was observed with 10 microM Trp-P-1, and at this concentration the amount of cell protein and the activity of a non-specific enzyme, beta-galactosidase, were not affected. The mechanism of the reduction of the enzyme activity was clarified by kinetical studies. The amine reduced the affinity of tyrosine hydroxylase to a cofactor, tetrahydrobiopterin. The alteration of the enzymatic properties by Trp-P-1 was discussed in relation to the possible effect on catecholamine metabolism in the brain.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1991

Immobilization stress induces interleukin-1 beta mRNA in the rat hypothalamus.

Immobilization stress induced interleukin-1 beta (IL-1 beta) mRNA in the rat hypothalamus. IL-1 beta mRNA was induced at 30 min after the start of immobilization, reached a maximum at 60 min and then was still detected with a decreased level at 120 min. However, 240 min after the start of the immobilization, IL-1 beta mRNA became hardly detectable despite the continuance of immobilization. Distinct expression of IL-1 beta mRNA was not detected in any other brain region examined at 30 and 60 min after the start of immobilization. These results demonstrate that the immobilization stress induces the expression of IL-1 beta mRNA solely in the hypothalamus and suggest that IL-1 beta is involved in the response to stress there.

Animals↗
PubMed1991

Cloning by functional expression of platelet-activating factor receptor from guinea-pig lung.

Platelet-activating factor (PAF), a unique phospholipid mediator, possesses potent proinflammatory, smooth-muscle contractile and hypotensive activities, and appears to be crucial in the pathogenesis of bronchial asthma and in the lethality of endotoxin and anaphylactic shock. Despite this, little is known of the molecular properties of the PAF receptor and related signal transduction systems. Although several lines of evidence suggest that activation of the PAF receptor stimulates phospholipase C and subsequent inositol trisphosphate formation through G protein(s), the PAF receptor and calcium channel are reported to show a close relation. As a first approach to cloning lipid autacoid receptors, we have isolated complementary DNA for the PAF receptors. Our strategy involved gene expression in Xenopus laevis oocytes and electrophysiological detection of PAF-induced responses. Sequence analysis indicates that the receptor belongs to the superfamily of G protein-coupled receptors.

Amino Acid Sequence↗
PubMed1991

Multiple diffuse hemangiomas of the large intestine.

A 54-year-old male case with multiple, diffuse hemangiomas of the large intestine is described. Large diffuse hemangiomas were located at the rectosigmoid and the ascending colon. Some polypoid lesions were located on the transverse colon. Tiny calcifications representing phleboliths were detected in those lesions. No skin hemangiomas were present. Although he did not manifest systemic bleeding tendency, blood examinations demonstrated the presence of mild consumption coagulopathy.

Colonic Polyps↗
PubMed1991

Serotonin, but neither noradrenaline nor GABA, inhibits capsaicin-evoked release of immunoreactive somatostatin from slices of rat spinal cord.

It has been suggested that somatostatin is involved in nociceptive transmission in the dorsal horn and that it is contained in small primary afferent neurons. In the present experiments, to elucidate neural systems inhibiting the release of somatostatin from the primary afferent terminals, we examined the effects of serotonin, noradrenaline and gamma-aminobutyric acid on the capsaicin-evoked, dorsal-rhizotomy-sensitive and tetrodotoxin-insensitive release of immunoreactive somatostatin, 98.7% of which was somatostatin itself, from the dorsal-half slices of lumbar and cervical enlargements of rat spinal cord. Serotonin (30-100 microM) suppressed the evoked release in a concentration-dependent manner, and the suppression was antagonized by methysergide (100 microM). The evoked release of immunoreactive somatostatin was not inhibited by noradrenaline (100 microM) or gamma-aminobutyric acid (100 microM). The present results suggest that the serotonergic systems exert an inhibitory effect on the release of somatostatin from the central terminals of primary sensory neurons.

Animals↗
PubMed1991

Involvement of central beta-adrenoceptors in the induction of hypothalamic interleukin-1 beta mRNA by methamphetamine.

Methamphetamine (2-15 mg/kg, i.p.) has been shown to induce interleukin-1 beta (IL-1 beta) mRNA in the rat hypothalamus. The induction of IL-1 beta mRNA was blocked by intraperitoneal pretreatment with beta-blockers propranolol (0.1-1 mg/kg, but not 0.01 mg/kg) and pindolol (0.3 and 1 mg/kg). Prazosin (1 and 5 mg/kg) and yohimbine (1 and 5 mg/kg), alpha-blockers and haloperidol (1 mg/kg), a dopamine antagonist, produced partial and little suppression, respectively. When injected intracerebroventricularly (i.c.v.), propranolol, but neither prazosin nor yohimbine, significantly suppressed the methamphetamine-induced expression of IL-1 beta mRNA at a dose of 1 nmol/rat. An i.c.v. injection of the beta-adrenoceptor agonist isoproterenol (1 and 3 micrograms/rat) dose-dependently increased the hypothalamic level of IL-1 beta mRNA. The present results suggest that the induction of hypothalamic IL-1 beta mRNA by methamphetamine is mediated by beta-adrenoceptors in the brain.

Adrenergic alpha-Antagonists↗
PubMed1991

Effect of coenzyme Q10 on structural alterations in the renal membrane of stroke-prone spontaneously hypertensive rats.

To test the hypothesis that structural abnormalities exist in the kidney membrane of spontaneously hypertensive rats, we examined the effect of long-term administration of coenzyme Q10 on membrane lipid alterations in the kidney of stroke-prone spontaneously hypertensive rats (SHRSP). As compared with normotensive Wistar-Kyoto rats, renal membrane phospholipids, especially phosphatidylcholine and phosphatidylethanolamine, decreased and renal phospholipase A2 activity was enhanced with age in untreated SHRSP. Treatment with coenzyme Q10 attenuated the elevation of blood pressure, the membranous phospholipid degradation, and the enhanced phospholipase A2 activity. These results suggest that one factor contributing to the progress of hypertension is a structural membrane abnormality that alters the physical and functional properties of the cell membrane, and coenzyme Q10 might protect the renal membrane from damage due to hypertension in SHRSP.

Animals↗
PubMed1991

Phenotypic analysis of CD23+ peripheral blood mononuclear cells in atopic dermatitis.

There is an increase in the number of CD23+ cells in peripheral blood mononuclear cells (PBMC) in atopic dermatitis (AD). We analysed the subpopulation of CD23+ PBMC in 11 patients with AD and in 10 healthy controls and found that B cells (CD20+) and non-T, non-B cells (CD3- CD20-) (mainly monocytes) were responsible for the elevation of CD23+ cells. CD23+ T cells (CD3+) comprised only 4.6% of total CD23+ cells in AD. The percentage of CD23+ cells did not correlate with the serum log IgE level nor with clinical severity of AD. Interleukin 4 (IL-4) induced the expression of CD23 antigen in PBMC both in AD and in healthy controls in a dose-dependent manner in vitro. This enhancing effect of IL-4 was completely abrogated by the addition of anti-IL-4 monoclonal antibody. Other cytokines such as IL-1, IL-2, IL-3, IFN-alpha, IFN-gamma and TNF-alpha had no significant effects on CD23 expression.

Adolescent↗
PubMed1991

Malignancy associated with chronic empyema: radiologic assessment.

Radiologic findings of six cases of malignancy associated with chronic empyema 5-39 years in duration were reviewed. Pathologic examination confirmed three B-cell non-Hodgkin lymphomas, one round-cell sarcoma, one mesothelioma, and one adenocarcinoma. Retrospective findings on plain chest radiographs suggested the occurrence of malignancy: increased radiopacity in the thoracic cavity, soft-tissue bulgings and/or unsharpness of fat planes in the chest walls, destruction of bone near the empyema, and extensive medial deviation of the calcified pleurae. Computed tomography delineated masses with soft-tissue attenuation more clearly than radiography in all cases. Magnetic resonance images of three cases were informative because empyema cavities were surrounded by low-intensity rims, and two of them showed a signal intensity different from that of necrotic tumors. Scintigraphy revealed increased uptake of gallium in all cases. Ultrasonography was useful for biopsy guidance. Every radiologist should know this entity in observation of chest radiographs obtained in patients with chronic empyema, and further radiologic assessment and aggressive biopsy are recommended if malignancy is suspected.

Adenocarcinoma↗
PubMed1991

The anti-tachycardic mechanism of a direct-acting vasodilator, budralazine, in rats.

The present study was undertaken to elucidate the anti-tachycardic effect of a direct-acting vasodilator, budralazine, using an electrophysiological technique. Normotensive male Wistar rats were used. Rats were anesthetized intraperitoneally with urethane and alpha-chloralose. Intravenous administration of budralazine (0.5-5.0 mg/kg) produced a dose-dependent reduction of mean arterial pressure in anesthetized rats. At doses of 0.5 and 1.0 mg/kg, budralazine induced bradycardia accompanied with a decrease in cardiac sympathetic nerve activity (ICNA). Preganglionic adrenal sympathetic nerve activity (ASNA) was also reduced by budralazine (1.0 mg/kg). A 0.5 mg/kg of budralazine neither influenced carotid sinus nerve activity nor augmented aortic depressor nerve activity (ADNA). On the contrary, at dose of 5.0 mg/kg, budralazine produced a tachycardia accompanied with increases in both ICNA and ASNA. The ADNA was decreased by budralazine (5.0 mg/kg) significantly. These findings suggest that the central sympathoinhibitory action of budralazine may be responsible for the anti-tachycardic effect of budralazine and baroreceptor-mediated tachycardia occurred after high dose of budralazine.

Afferent Pathways↗
PubMed1991

A disorganized increase of galanin-like immunoreactivity in cerebral cortex of Alzheimer-type dementia brains.

Galanin (GAL), a neuropeptide which has been reported to inhibit the evoked release of acetylcholine, is widely distributed in the mammalian central nervous system. In the present study, GAL-like immunoreactivity (LI) was measured in the cerebral cortex of autopsy brains of patients with the Alzheimer-type dementia and controls using an enzyme immunoassay technique. GAL-LI tended to be increased in the ATD brains and the difference was statistically significant in the frontal cortex. Moreover, although significant correlations of GAL-LI between regions of the cerebral cortex were found in the control brains, no such correlations were found in the ATD brains. These findings suggest a disorganized increase in GAL-LI in the cortex of ATD brains.

Alzheimer Disease↗
PubMed1991

[Flomoxef in the pediatric surgical field].

Basic and clinical studies of flomoxef (6315-S, FMOX) were performed in the pediatric surgical field. The results obtained are summarized as follows: 1. FMOX was administered to 7 pediatric patients with biliary atresia (FMOX 20 mg/kg, i.v.d.). Peak biliary levels of FMOX were obtained at 1 hour after finishing administration by drip infusion, and were higher than those in blood 1 hours after finishing administration by drip infusion. 2. Urinary excretion was excellent, and urinary recovery rates were 57.8-97.8%. 3. FMOX was administered to 5 patients in the pediatric surgical field. One case was phlegmon, and other 4 cases were premature babies for postoperative prophylactic use. Clinical results were excellent in 1 case, good in 4 cases, with an overall efficacy rate of 100%. No clinical and laboratory side effects due to the administration FMOX were observed. It was concluded that FMOX was a safe and effective antibiotic in the pediatric surgical field.

Age Factors↗