Biomedical subjects

T Moriya

Publications and source records attributed to T Moriya.

At least 145 records · Page 8Linked to original sources

PubMed1997

Decreased level of light-induced Fos expression in the suprachiasmatic nucleus of diabetic rats.

We assessed light-induced Fos-immunoreactive cells in the suprachiasmatic nucleus of diabetic rats. The number of Fos-immunoreactive cells significantly decreased in diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats as compared with control Long-Evans Tokushima Otsuka (LETO) rats. In contrast there was no decrease in the number of Fos-immunoreactive cells in young OLETF rats which have not yet developed diabetes. Two months after the administration of streptozotocin (STZ) to Wistar rats, the number of Fos-immunoreactive cells significantly decreased, although 1 week after the administration of STZ, the number had not yet changed in these STZ-induced diabetic rats. These results suggest that chronic diabetic (hyperglycemic) conditions may affect the light entraining responses in the suprachiasmatic nucleus (SCN).

Animals↗

PubMed1997

A deletion in the sapA homologue cluster is responsible for the loss of the S-layer in Campylobacter fetus strain TK.

The surface array protein (SAP) of Campylobacter fetus strain TK is encoded by seven homologous sapA genes clustered on the chromosomal DNA. The spontaneously arising variant strain TK(SAP-) produces no SAP and carries an approximately 10-kb chromosomal deletion. To elucidate the mechanism underlying the loss of SAP synthesis, we analyzed the region containing the sapA homologues and the deletion. We constructed a physical map of the sapA cluster region by aligning the clones that contain sapA homologues. These analyses demonstrated that all sapA homologues were located within a limited region of about 50 kb of chromosomal DNA of strain TK. The TK(SAP-) deletion was located within this cluster and was 13.3 kb in size. The deletion occurred between two sapA homologues and resulted in the formation of a chimeric sapA homologue in the variant strain. Sequence analysis of the upstream regions and the conserved regions of all sapA homologues revealed a high degree of similarity. However, only one sapA homologue contained a putative promoter sequence. This promoter sequence was located in the deleted region. Thus, the deletion of the promoter appears to be responsible for the loss of SAP expression in TK(SAP-).

Bacterial Outer Membrane Proteins↗

PubMed1997

Breast carcinoma with myeloid metaplasia--a case report.

A 49 year-old female had been suffering from primary myelofibrosis since February 1987 without receiving any treatment. In 1994, a breast mass was detected. Breast tumor biopsy revealed tubular carcinoma with intraductal components and multinucleated giant cells in the loose and myxoid stroma. The giant cells were thought to be megakaryocytes because both Factor VIII and platelet glycoprotein GP IIIa were detected in their cytoplasm. While additional mastectomy specimens and the axillary lymph nodes also revealed prominent myeloid metaplasia, there was no proliferation of the cancer cells. Granulocytic series stained for chloroacetate esterase and very few erythrocytic series were observed. This is the first case in which breast carcinoma and myeloid metaplasia coexisted in the same breast tumor.

Adenocarcinoma↗

PubMed1997

Beta 2 microglobulin haemodialysis related amyloidosis: distinctive gross features of gastrointestinal involvement.

Two cases of beta 2 microglobulin amyloidosis following long term haemodialysis found during necropsy are reported. The patients were 59 and 65 year old Japanese men, respectively. In both cases, systemic distribution of beta 2 microglobulin amyloid deposits was observed. The gastrointestinal tract including the stomach, small intestine, and colon showed the distinctive gross feature of rippled appearance, which was characterised by serosal wrinkles along the muscle layer arrangement. These areas were confirmed to contain deposits of beta 2 microglobulin in the muscularis propria. Although the outline of the muscle layers was preserved, most muscle fibres, encircled by the amyloid deposits, were atrophic or had disappeared microscopically. In neither case could a definite diagnosis of amyloidosis be made while the patient was alive. Interestingly, the oesophagus presented less involvement compared to the remainder of the gastrointestinal tract. In comparison with the AA or AL type of amyloidosis, beta 2 microglobulin haemodialysis related amyloidosis showed a rippled appearance of the serosal rather than mucosal changes, which may explain the difficulty in diagnosing amyloid deposits using biopsies of the gastrointestinal tract.

Aged↗

PubMed1997

[Detection of GBV-C RNA among non B non C hepatocellular carcinoma patients].

Recently, an RNA virus member of the flaviviridae, GBVirus C(GBV-C) was isolated from the serum of patient with cryptogenic hepatitis, but clinical significance for this virus has been not known now. To estimate the prevalence of GBV-C, we investigated the presence of GBV-C RNA by reverse transcription-nested polymerase chain reaction in the serum from various liver disease patients. The results were summarized as follows: [Table: see text] Among these, only 5 patients gave positive results, and these 5 cases had the history of blood transfusion before. Especially both non B non C HCC patient and non A non B non C fulminant hepatitis patient were negative for GBV-C on admission, while positive after blood transfusion as treatment. In the non B non C HCC patient, GBV-C RNA persisted over a period of several months after transfusion, while no remarkable elevation of ALT was observed. These results demonstrated that GBV-C/HGV may be transfusion-transmissible, and may not associated with severe chronic liver disease such as liver cirrhosis or HCC.

Biomarkers↗

PubMed1997

[Acute pulmonary thromboembolism treated with E6010].

A 22-year-old man was admitted to our hospital because of sudden dyspnea and dizziness. Hypoxemia was found. Lung perfusion scintigraphy and pulmonary angiography showed massive pulmonary thromboembolism. The patient received E6010, a derivative of tissue plasminogen activator by intravenous injection for about 2 minutes. One hour after this treatment, pulmonary angiography showed lysis of the ciot, the pulmonary arterial pressure had decreased, and the cardiac index and PaO2 had increased. Despite anticoagulant therapy, pulmonary embolism recurred so we implanted a Greenfield filter in the inferior vena cava. This was the first case of pulmonary thromboembolism in which E6010 had a beneficial effect. We were also able to document hemodynamic and radiologic changes after intravenous infusion of this drug. Recurrent pulmonary embolism is an indication for filter placement, and this patient will need a long period of follow-up.

Acute Disease↗

PubMed1996

Preference for background color of the Xenopus laevis tadpole.

The background color preferences of three age groups of Xenopus laevis tadpoles (young-stages tadpoles [stages 44-46], premetamorphic tadpoles [stages 54-56], and metamorphic tadpoles [stages 58-60]) were examined. Young tadpoles selected a white background, metamorphic tadpoles preferred a black background, and premetamorphic tadpoles selected a white or black background consistent with the background black or white of the test box on which they previously were conditioned. If premetamorphic tadpoles were conditioned in the checkerboard-pattern (white and black) box or white box which was placed a small black square at the center of the box, they preferred to stay in the white area just after transfer to the test box, then shifted their preference for background color to black strongly. Premetamorphic tadpoles conditioned on a white background lost this preference if kept in the dark for 12 hours. Blinding of premetamorphic tadpoles by severance of the optic nerves resulted in loss of preference for a specific background matching the white or black background to which they had been adapted while sighted. Given a choice 3 days postblinding, they tended to congregate on a white background. Injection of MSH into premetamorphic tadpoles conditioned to white shifted their preference to black. In contrast, injection of melatonin stimulated black adapted tadpoles to select a white background. Young frogs showed a preference for a black background.

Animals↗

PubMed1996

Involvement of 5-HT1A receptor mechanisms in the inhibitory effects of methamphetamine on photic responses in the rodent suprachiasmatic nucleus.

We examined the role of serotonin 1A (5-HT1A) receptors in the inhibitory effects of methamphetamine (MA) on photic entrainment to the circadian pacemaker in the suprachiasmatic nucleus (SCN) of rodents. MA inhibited optic nerve stimulation-evoked field potential in the SCN, light-induced Fos expression in the SCN and light-induced phase shift of hamster wheel-running rhythm. NAN-190, a 5-HT1A receptor antagonist, eliminated the inhibitory effects of MA. NAN-190 has also been reported to antagonize alpha 1 adrenergic receptors. However, prazosin, which selectively antagonizes alpha 1 adrenergic receptors, did not affect the inhibitory action of MA on light-induced Fos expression. In addition, parachloroamphetamine, which is known to be a 5-HT releaser, dose-dependently inhibited light-induced phase shift of wheel-running rhythm. These findings suggest that elevation of endogenous 5-HT levels by MA inhibits the photic entraining responses of the circadian pacemaker in the SCN via 5-HT1A receptor stimulation of the 5-HT released by MA.

Animals↗

PubMed1996

Adenosine A1-receptor agonist attenuates the light-induced phase shifts and fos expression in vivo and optic nerve stimulation-evoked field potentials in the suprachiasmatic nucleus in vitro.

Adenosine is widely accepted to act as an inhibitory neuromodulator in the mammalian central nervous system. In the present study, we examined whether adenosine receptor agonist modifies the photic entraining responses in the rat suprachiasmatic nucleus both in vivo and in vitro. Light (200 lux, 15 min)-induced phase shifts of hamster wheel-running rhythms was attenuated by a systemic administration of A1-adenosine receptor agonist N6-cyclohexyladenosine (N-CHA) in a dose-dependent manner; 0.5 mg/kg N-CHA caused 60% inhibition of light-induced phase shifts. On the other hand, A2-adenosine receptor agonist N6-[2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl)-ethyl]adenosine (DPMA) failed to inhibit light-induced phase shifts. Systemic administration of N-CHA but not of DPMA inhibited light (300 lux, 1 h)-induced Fos expression in the suprachiasmatic nucleus in a dose-dependent manner; 1 mg/kg N-CHA caused 73% inhibition of light-induced Fos expression. Bath application of N-CHA but not of DPMA inhibited optic nerve stimulation-evoked field potentials in rat suprachiasmatic nucleus slices. The present results suggest that activation of adenosine A1-receptor attenuates the photic input through the inhibition of retinohypotalamic pathway to the SCN.

Adenosine↗

PubMed1996

Light-sensitive response in melanophores of Xenopus laevis: II.Rho is involved in light-induced melanin aggregation.

Melanophores of the isolated tail fin of the Xenopus tadpole aggregate melanin granules in response to light. This aggregation was found to be inhibited by subcutaneous injection of exoenzyme C3 of Clostridium botulinum. A 26 kDa protein in homogenate obtained from the Xenopus tail fin was ADP-ribosylated by exoenzyme C3. This reaction was inhibited effectively by a monoclonal antibody, anti-Rho mab A5. raised against the small GTP-binding protein Rho. The extent of ADP-ribosylation depended on light and guanine nucleotide. Incubation under illumination partly reduced ADP-ribosylation and the reduction was restored by addition of guanine nucleotide during incubation. These findings suggest that Rho is involved in the photo-sensitive melanophore response as a signal transducer linking photo-stimuli to melanin granule translocation with Xenopus melanophores.

ADP Ribose Transferases↗

PubMed1996

Light-sensitive response in melanophores of Xenopus laevis: I. Spectral characteristics of melanophore response in isolated tail fin of Xenopus tadpole.

Melanophores in the isolated tail from the amphibian larvae Xenopus laevis, Hyla japonicus, Rana pirica, and Hynobius retardatus aggregated melanin granules in response to light and dispersed them when placed in darkness. The spectral characteristics for the melanin-aggregation response were examined by irradiating the Xenopus tail-fin locally (diameter, 2.1 mm) with monochromatic light (380-1,020 nm). The spectral region of wave length which induced melanosome aggregation depended on the light intensity but was limited to the visible spectrum. At low light intensity (1.59 microW/cm2, delta lambda = 5 nm), the aggregation response occurred in the spectral region between 400 and 600 nm and the maximum response was observed at 500 nm. This range is very close to the absorption spectrum of rhodopsin in the visual rod cell. Hypodermic injection of cGMP into isolated tail-fin induced a marked melanin-dispersion in spite of light-stimuli. When the tail-fin was treated with isobutylmethylxanthine (IBMX; phosophodiesterase inhibitor) in darkness and then was re-exposed to light, the aggregation response was inhibited. The photo-sensitive melanin aggregation was independent of a requirement for Ca2+ ions but melanosome dispersion in darkness was Ca(2+)-dependent. K(+)-rich Hanks' solution, ouabain (inhibitor of Na(+)-K(+)-ATPase) or nonactin (cation ionophore), which induced a change of the membrane potential of melanophores, inhibited the aggregation response when the melanophores were re-exposed to light after a period in darkness. These results suggest that the molecular mechanism of photoreception in melanophores of amphibian tadpoles is similar to that in visual cells.

1-Methyl-3-isobutylxanthine↗

PubMed1996

Cystic Hypersecretory Duct Carcinoma of the Breast:A Case Reprot Describing the Cytologic Features.

We report the clinical, cytological and pathological features of so-called cystic hypersecretory duct carcinoma occurring in a 60-year-old Japanese woman. The tumor mainfested a multicystic mass ultrasonographically, and aspiration biopsy cytology revealed atypical ductal epithelial cells with vacuolar cytoplasm. A modified radical mastectomy was performed. Histologically, the lesion was charcterized by many dilated ducts containing eosinophilic secretions, which resembled thyroid colloid. The ducts were lined by an intraductal micropapillary carcinoma with hobnail-shaped cells, and were positive for lactalbumin immunohistochemically. Additionally, a so-called cystic hypersecretory hyperplasia was seen in the surrounding breast parenchyma. Although a direct transition from the hyperplasia to the carcinoma was not proved, a close relationship between the two lesions was suggested.

Journal Article↗

PubMed1996

Chronic administration of methamphetamine does not affect the suprachiasmatic nucleus-operated circadian pacemaker in rats.

The effects of chronic administration of methamphetamine (MAP) on rat locomotor activity rhythm under light-dark (LD) housing and on neuronal activity rhythms from the suprachiasmatic nucleus (SCN) in vitro were investigated. Control rats exhibited an LD-entrained nocturnal locomotor rhythm. The firing rate of SCN neuronal activity was high during the light period and low during the dark period in control normal rats, and peak of firing activity occurred around zeitgeber time (ZT) 6. On the other hand, chronic MAP administration caused various disorganization of locomotor activity rhythms with a long free-running period (25-35 h). Neuronal activity rhythms of the SCN were unaffected by chronic MAP administration, that is, high during the light period and low during the dark period. The present findings suggested that the SCN maintained as a circadian pacemaker even under chronic MAP administration which affected overt rhythms.

Adrenergic Agents↗

PubMed1996

Resuscitation of Vibrio cholerae O1 strain TSI-4 from a viable but nonculturable state by heat shock.

Vibrio cholerae strain TSI-4 was incubated in an M9 salt solution at 15 degrees C for more than 100 days. The plate counts showed no viable cells on day 30, but a broth culture from that day showed the growth of bacteria. However, after 35 days the bacteria entered the nonculturable state, based on the assessment of both the plate counts and broth culture. A portion of the culture was heated at 45 degrees C for 1 min in a water bath and subsequently plated onto a nutrient agar plate. More than 1000 colonies were recovered after this heat-shock treatment. The recovered cells showed the same chromosomal DNA pattern in the restriction map and the same outer membrane protein pattern in SDS-PAGE. Recovery of viable cells by heat-shock was achieved in cultures grown on M9 salt but not from cultures grown in phosphate-buffered saline. This suggests that the presence of NH4Cl in the M9 salt solution may support the growth of the bacteria in a low nutrient medium, while also playing an important role in resuscitation.

Bacterial Proteins↗

PubMed1996

Effects of early insulin treatment on ultrastructural changes of glomeruli in diabetic rats revealed by the quick-freezing and deep-etching method.

The three-dimensional ultrastructure of glomerular basement membrane (GBM) and mesangial matrix (MM) at an early stage of streptozotocin (STZ)-induced diabetes mellitus in rats was examined by the quick-freezing and deep-etching method. In diabetic rats, the GBM inner layer was diffusely enlarged and the meshwork structure not only in the GBM middle layer but also in the MM became markedly irregular due to the rupture of fine fibrils. This irregularity and enlargement of the mesh pores in diabetic rats developed during the experimental period and was significantly different from results in control rats. Insulin treatment from 1 week after STZ injection had significant effects in preventing the ultrastructural changes in the GBM and MM. It is suggested that early insulin treatment has significant effects in preventing size barrier disturbance of GBM and MM in STZ-induced diabetes.

Animals↗

PubMed1996

Analysis of the core region of HCV genome isolated from patients with chronic hepatitis C during intervals of normal ALT concentration.

We determined the core region nucleotide and amino acid sequences in specimens from two patients with chronic hepatitis C during intervals of normal and elevated alanine aminotransferase (ALT) concentrations. When the ALT concentrations remained normal, the serum HCR-RNA concentration exceeded that before therapy and most of the clones that could be sequenced had a deletion or an amber mutation. The clones isolated from a HLA B44-positive patient had a mutation at amino acid 91. These results suggest that expression of the wild-type HCV core region genome may be associated with liver cell damage.

Aged↗

PubMed1996

Methamphetamine modifies the photic entraining responses in the rodent suprachiasmatic nucleus via serotonin release.

We examined whether methamphetamine modifies the photic entraining responses in the rat suprachiasmatic nucleus. Optic nerve stimulation increased vasoactive intestinal polypeptide release from rat suprachiasmatic nucleus slices, and methamphetamine inhibited this increase in a concentration-dependent manner. Optic nerve stimulation has been reported to evoke field potentials in rat suprachiasmatic nucleus slices. Methamphetamine attenuated this field potential, and maximal inhibition (75.5%) was achieved at a concentration of 100 microM. Systemic administration of methamphetamine (1-5 mg/kg) inhibited light (300 lux, 1h)-induced Fos expression in the suprachiasmatic nucleus; methamphetamine at a dose of 5 mg/kg, i.p. caused 40% inhibition of light-induced Fos expression. We examined whether the inhibitory effect of methamphetamine on photic entraining responses mediates serotonin release from the suprachiasmatic nucleus. High-performance liquid chromatographic analysis revealed that methamphetamine application increased serotonin release from rat suprachiasmatic nucleus slices in a concentration-dependent manner, but did not affect noradrenaline release. In addition, reduction of serotonin content attenuated the effect of methamphetamine on field potential induced by optic nerve stimulation in vitro and also light-induced phase advances of wheel running activity rhythm in vivo. The present results support the idea that methamphetamine produces an inhibitory effect on photic entrainment in the suprachiasmatic nucleus via serotonin release.

Animals↗

PubMed1996

Construction of a ferritin-deficient mutant of Campylobacter jejuni: contribution of ferritin to iron storage and protection against oxidative stress.

The ferritin-encoding gene (cft) of Campylobacter jejuni was cloned and sequenced. The nucleotide sequence of cft had a 501 bp open reading frame for a protein with 167 amino acids and a predicted molecular mass of 19 180 Da, and showed a high similarity to that of Helicobacter pylori and Escherichia coli ferritin genes. To determine the biological function of ferritin in C. jejuni, a ferritin-deficient mutant was constructed. The growth of ferritin-deficient strain SNA 1 was clearly inhibited under iron deprivation. The ferritin-deficient mutant was more sensitive to killing by H2O2 and paraquat than the isogenic parent strain. These findings demonstrate that ferritin in C. jejuni makes a significant contribution to both iron storage and protection from intracellular iron overload, and resulting iron-mediated oxidative stress.

Amino Acid Sequence↗