Search PubMed⌕ Search

Biomedical subjects

M Nomoto

Publications and source records attributed to M Nomoto.

At least 109 records · Page 6Linked to original sources
PubMed1995

Effects of GBR 12909 on locomotor activity and dopamine turnover in mice: comparison with apomorphine.

The effects of GBR 12909 1-[2-[bis(4-fluorophenyl)methoxy]-ethyl]-4- [3-phenylpropyl]piperazine, a very potent and selective dopamine uptake inhibitor, and apomorphine, a dopamine receptor agonist, alone and in combination were investigated on locomotor activity and dopamine turnover in discrete brain regions of mice. The levels of dopamine and its metabolites were examined 40 min after the administration of GBR 12909 and/or apomorphine, when the effects of the drugs on locomotor activity were approximately at a peak. GBR 12909 (10 mg/kg i.p.) reversed a low dose of apomorphine (0.05 mg/kg s.c.)-induced suppression in locomotor activity and significantly increased this activity. Despite the dramatic change in the behavior, GBR 12909 did not influence the decrease in 3,4-dihydroxyphenylacetic acid (DOPAC)/dopamine ratio (which is one of the indications of transmitter turnover) induced by a low dose of apomorphine in the nucleus accumbens and striatum. In contrast, GBR 12909 did not enhance the high-dose apomorphine (2 mg/kg s.c.)-induced hyperlocomotion, and did not modify the larger decrease in dopamine turnover produced by the high dose of apomorphine in the frontal cortex, nucleus accumbens and striatum. This suggests that postsynaptic dopamine receptors may reach maximum stimulation at a high dose of apomorphine. These results indicate that a behavioral change induced via stimulation of postsynaptic dopamine receptors does not necessarily lead to an alteration in dopamine turnover.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1995

p53 immunoreactive stain and early colorectal adenocarcinomas.

565 cases of early colorectal adenocarcinomas were used in this study to examine mechanisms of carcinogenesis. Specimens were paraffin embedded and histological sections were stained with haematoxylin-eosin and p53. Macroscopically, early colorectal adenocarcinomas could be classified into two types: protruding and depressed. The former were composed of branching glands, while the latter were composed of straight glands which opened to the surface. The p53 positive ratio was similar for protruding tumours but was higher in depressed submucosal invasive adenocarcinomas than in depressed intramucosal adenocarcinomas. These results raise the possibility of at least two pathways for colorectal carcinogenesis, adenoma-carcinoma lesions and de novo carcinoma lesions.

Adenocarcinoma↗
PubMed1995

Dominant role of the second heat shock element in expression of the HSP70-1 gene in rat liver after whole body hyperthermia.

We investigated the regulatory expression of the HSP70-1 gene in rat liver after whole body hyperthermia (rectal temperature of 42 degrees C for 30 min). After heat treatment, HSP70-1 mRNA showed a peak at 1 h, and its protein product began to increase at 3 h. Under these conditions, we identified cis-acting elements involved in the regulatory expression of the HSP70-1 gene by in vivo genomic footprinting. We observed that the second heat shock element (HSE-2; -201 to -178) was clearly protected from methylation by dimethyl sulfate in parallel with the increase in HSP70-1 mRNA. On the contrary, the most proximal HSE-1 (-120 to -101) was protected only slightly. Furthermore, the flanking regions of HSE-2, that is, an NF-kappa B-like element on the upstream side and a GC box on the down-stream side were also protected simultaneously in accordance with the induced expression of the HSP70-1 gene. Gel mobility shift assays with nuclear extracts from rat liver at 30 min after heat treatment showed maximal DNA binding activity equally with oligonucleotides containing HSE-1 and HSE-2, respectively, and also demonstrated the participation of heat shock factor-1 (HSF1) in both cases. These results suggest that, in addition to HSF1, other regulatory factors might be involved in the dominant protection of HSE-2 in the promoter of the HSP70-1 gene in rat liver after whole body hyperthermia.

Animals↗
PubMed1995

Induction of heat shock protein 70 and nucleolin and their intracellular distribution during early stage of liver regeneration.

Our previous work demonstrated a simultaneous induction of Hsp70 and nucleolin mRNA during the prereplicative stage of hepatocytes after partial hepatectomy [Ohmori, H. et al. (1990) Exp. Cell Res. 189, 227-232]. In the present study, changes of intracellular localization of these proteins were examined. Nucleolin, which mainly localized in the nucleus, increased with time and accumulated in the nucleolus around 12-18 h after partial hepatectomy. Hsp70 protein also increased slightly around 6-12 h after the operation. In accordance with this increase, immunohistochemical staining revealed that almost all nuclei of hepatocytes became Hsp70-positive, although Hsp70 was seen to be dispersed throughout the nucleoplasm and nucleolus at all times examined. Next, we isolated a cDNA clone of ribosomal protein (S-17) and examined its behavior. Induction of S-17 mRNA was observed to be essentially similar to that of nucleolin mRNA in regenerating rat liver, although inductions of histone H2A and H4 occurred at a later time, that is, in parallel with DNA synthesis. Furthermore, we observed a simultaneous induction of Hsp70 and nucleolin mRNA by serum-stimulation after serum-depletion in HeLa and IAR-20 (rat) culture cells. These results suggest that the induction of Hsp70, in addition to nucleolin, was not fortuitous but may be involved in the early events of liver regeneration.

Animals↗
PubMed1995

Mucin antigens expression and Ki-67 labeling in breast cancer: the peculiarity in scirrhous carcinoma.

The expression of mucin-related antigens (Tn, T, Sialosyl-Tn [STn], DF3 [mammary-type apomucin related antigen], and intestinal-MRP [intestinal-type apomucin related antigen]) as well as Ki-67 labeling was examined in 58 mammary invasive ductal carcinomas (IDC) divided into 26 scirrhous subtype (SC) and 32 non-scirrhous subtype comprising papillotubular carcinoma and solid-tubular carcinoma (PT-ST). These data were analyzed in connection with the various pathological prognostic factors such as nodal status, tumor size, estrogen receptor status and histological grading of carcinomas. The results were as follows: (a) in SC, the expression rate of Tn was significantly higher in the cases with positive lymph node metastasis or with large tumor size (> 2 cm) than in those with negative lymph node metastasis or with small tumor size (< or = 2 cm); (b) in PT-ST, the expression rate of STn was higher in the cases with positive lymph node metastasis or with large tumor size than in those with negative lymph node metastasis or with small tumor size; (c) in SC, Ki-67 labeling was significantly higher in the cases with positive lymph node metastasis than in those with negative lymph node metastasis; and (d) in PT-ST, Ki-67 labeling was lower in the cases with positive lymph node metastasis than in those with negative lymph node metastasis. In conclusion, Tn antigen expression was correlated with pathological prognostic factors in SC but not in PT-ST, whereas STn antigen expression was correlated with pathological prognostic factors in PT-ST but not in SC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma, Scirrhous↗
PubMed1995

Role of capsaicin-sensitive trigeminal nerves in development of hyperreactive nasal symptoms in guinea pig model of nasal allergy.

The effect of capsaicin pretreatment on frequency of sneezing, decrease of nasal patency, and increase of vascular dye leakage induced by antigen or histamine challenge on the guinea pig nasal mucosa was investigated. The animals were sensitized intraperitoneally with ovalbumin. Capsaicin pretreatment significantly inhibited sneezing induced by nasal challenge with histamine and antigen, indicating that capsaicin-sensitive sensory nerves constitute an afferent pathway of the sneezing reflex in nasal allergy. Although capsaicin pretreatment tended to inhibit the decrease of nasal patency and the increase of vascular dye leakage of the nasal mucosa induced by antigen challenge, this tendency was not statistically significant. The present study indicated that the participation of a local reflex via capsaicin-sensitive trigeminal nerves in nasal vascular responses observed after antigen challenge in the guinea pig model of nasal allergy is rather small compared to the large direct vascular effects of chemical mediators released from basophilic cells in the nasal mucosa.

Airway Resistance↗
PubMed1995

[Application of the common marmoset to pharmacological studies].

Application of the common marmoset to pharmacological studies was reviewed, especially employment of the animal as a model of Parkinson's disease were presented. The common marmoset is one of the New World monkeys with a body weight of 300-350 g. It is small enough to be easily handled and to be kept as a group in a room. In the fields of pharmacology, it has been used in studies of plasma renin activity inhibitors, lipoprotein, memory/learning, obstetrics, transplantation, toxicology, anxiolytic agents and virology/immunology. We showed that the common marmoset was a useful animal for studies on Parkinson's disease, dopamine metabolism by microdialysis and nausea/vomiting. The common marmoset was sensitive to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and developed permanent parkinsonism after MPTP injection. MPTP-treated common marmosets showed tremor and akinesia, and it remarkably responded to antiparkinsonian agents. A dopamine D1 agonist, which caused stereotyped behavior in rats, did not reverse parkinsonism in humans. We showed this agent did not have any antiparkinsonian effects on MPTP-treated common marmosets. MAO has subtypes, A and B, that have differences of distribution in different species. MAO type B inhibitors were applied for the treatment of Parkinson's disease. MAO subtype B inhibitors do not cause any change in behavior or extracellular concentration of dopamine or its metabolites in rodents. In MPTP-treated common marmosets, however, administration of a MAO type B inhibitor increased the antiparkinsonian effects of levodopa and decreased dopamine metabolites. The common marmoset is a suitable animal for the study of MAO type B inhibitors.

Animal Husbandry↗
PubMed1995

Non-secretory alpha chain disease involving stomach, small intestine and colon.

A case of alpha chain disease, involving stomach, small and large intestine, and caecum with poor prognosis is reported. Endoscopic examination revealed gastric erosion, edematous mucosa with enlarged villi of duodenum and jejunum, multiple hyperplastic lymph follicles of terminal ileum and thickening mucosa of caecum. Light microscopy revealed a conspicuous infiltration of plasma cells and lymphocytes in gastric, duodenal, jejunal and caecal lamina propria. Immunohistochemistry demonstrated alpha heavy chain protein devoid of light chain in these plasma cells. The patient developed paralytic ileus and died of septic shock on the 179th hospital day.

Colon↗
PubMed1994

Antiparkinsonian activity of talipexole in MPTP-treated monkeys: in combination with L-dopa and as chronic treatment.

We examined whether or not the antiparkinsonian activity of talipexole (B-HT 920, 6-allyl-2-amino-5,6,7,8-tetrahydro-4H-thiazolo[4,5-d]-azepine) could be optimised by combination with L-3,4-dihydroxyphenylalanine (L-dopa). Additionally, the effects of chronic treatment with talipexole on motor behavior were investigated using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated and normal common marmosets. Administration of MPTP (0.5 mg/animal i.v. once or twice) to marmosets induced persistent parkinsonian motor deficits. The antiparkinsonian activity of talipexole (40 micrograms/kg s.c.) was significantly enhanced by its combination with L-dopa (30 mg/kg i.p.). This may further support the postulated postsynaptic dopamine D2 receptor agonist properties of talipexole. Chronic treatment with talipexole (a daily dose of 40 micrograms/kg s.c. for 21 days) did not lead to tolerance to the antiparkinsonian activity in MPTP-treated animals. No obvious dyskinesia was seen throughout the chronic treatment. In contrast, in normal marmosets, talipexole at a dose of 80 micrograms/kg which is a dose sufficient to induce hyperactivity did not increase motor activity during the treatment repeated for 21 days. These results suggest that talipexole is a selective dopamine D2 receptor agonist drug of potential use in the treatment of Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1994

Effects of bifemelane on parkinsonism induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the common marmoset.

The effects of bifemelane on parkinsonism were shown in MPTP-treated common marmosets. The administration of bifemelane increased locomotor activity in MPTP-treated marmosets but not in normal control marmosets. In a microdialysis study, extracellular levels of dopamine and its metabolites increased following the administration of bifemelane. These results indicate that it is worth studying the effects of bifemelane hydrochloride on patients with Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1994

Reduction by NG-nitro-L-arginine of H2O2-induced endothelial cell injury.

1. The effects of three analogues of NG-nitro-L-arginine (L-NOARG) and NG-monomethyl-L-arginine (L-NMMA), inhibitors of nitric oxide (NO) synthase, on hydrogen peroxide (H2O2)-induced endothelial cell injury were studied. 2. Endothelial cell injury was assessed by measuring the release of intracellular lactate dehydrogenase (LDH) and 51Cr. 3. Addition of H2O2 (250-1,000 microM) to endothelial cells induced the release of LDH dose-dependently. The release of LDH was reduced by pretreatment with NG-nitro-L-arginine methyl ester (L-NAME, 10(-4)-4 x 10(-3) M), L-NOARG (10(-4)-4 x 10(-3) M) and NG-nitro-L-arginine benzyl ester (L-NABE, 10(-4)-4 x 10(-3) M), inhibitors of NO synthase. 4. L-NOARG analogues also reduced H2O2-induced 51Cr release from endothelial cells, while L-NMMA had no effect. 5. The protective effect of L-NAME was not reversed by addition of L-arginine (L-Arg, 1-10 mM). 6. Both L-NAME and L-NMMA completely inhibited L-Arg metabolism to L-citrulline coupled with NO synthesis. 7. These findings suggest that L-NOARG analogues but not L-NMMA reduced H2O2-induced endothelial cell injury, and that these effects may not be related to inhibition of NO production.

Amino Acid Oxidoreductases↗
PubMed1994

Effect of psychic stimulation on plasma catecholamine concentrations and nasal patency in patients with nasal allergy.

To compare the degree of sympathoadrenal and nasal vascular response to psychic stimulation between patients with nasal allergy and normal controls, we measured the changes in plasma norepinephrine and epinephrine concentrations and nasal patency elicited by cannulation into the forearm vein and mental arithmetic in 28 patients with nasal allergy and age- and sex-matched normal controls. Ten of the 28 allergy patients had markedly swollen, pale, edematous nasal mucosa and served as a subgroup of nasal allergy patients. Plasma catecholamine levels increased significantly, with a synchronous increase of nasal patency, during stimulation. Among the three groups, no statistical differences were observed in plasma catecholamine levels either at rest or during stimulation. There was no significant difference in extent of increase of nasal patency induced by stimulation in the total group of subjects with nasal allergy compared with normal controls. However, it was significantly smaller in a subgroup of nasal allergy patients having markedly pale, edematous swelling of the nasal mucosa.

Adult↗
PubMed1994

[Magnetic resonance imaging (MRI) of bone marrow necrosis].

Magnetic resonance (MR) of bone marrow was studied in two cases of acute leukemia which showed bone marrow necrosis. Case 1:A 24-year-old female was admitted because of sternum pain and bleeding tendency. She was diagnosed AML based on the peripheral blood picture. Bone marrow biopsy revealed the presence of bone marrow necrosis. T1 weighted imaging of MR showed low signal intensity in all vertebral marrow. Fatty marrow was demonstrated after achieving complete remission and the MR imaging of bone marrow changed to show high intensity, suggesting fat deposition. Case 2: A 19-year-old female suffered from chest pain and lumbago, and was diagnosed as ALL. DIC and bone marrow necrosis were confirmed during chemotherapy for remission induction. T1 weighted imaging showed the mosaic pattern of low and high signal intensity. She achieved complete remission and bone marrow clot revealed the presence of fatty marrow. Most areas of low signal intensity of T1 weighted imaging changed to those of high signal intensity. These observations suggest that necrotized bone marrow seemed to change to fatty marrow along with achieving remission. MR imaging study of bone marrow is useful for evaluating hematopoiesis in hematologic disorders.

Adult↗