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Biomedical subjects

M Satoh

Publications and source records attributed to M Satoh.

At least 577 records · Page 32Linked to original sources
PubMed1994

Biotinyl C-terminal-extended motilin as a biologically active receptor probe.

The synthesis, purification, and characterization of biotinylated analogues of motilin are reported. The C-terminal of canine motilin was extended by the addition of a cysteine residue, and then biotinylated. Biotinyl motilin was purified by following HPLC and characterized by amino acid analysis. Biotinylation of the ligand was confirmed by ELISA assay with the avidin-biotin system. Biotinyl motilin showed similar affinity for binding to rabbit gastric membrane fraction compared to unlabeled canine motilin, and also retained functional activity in its ability to cause contraction of rabbit duodenal segments. To determine the binding of biotinyl motilin in isolated rabbit antral smooth muscle, cells were incubated with the biotinyl motilin with and without excess of unlabeled motilin. Subsequent addition of avidin-biotinylated peroxidase complex showed the distribution of reaction products over the cell surface. Bioactive biotinyl motilin provides a useful probe for the demonstration of cell surface motilin receptors and will facilitate receptor purification and characterization.

Amino Acid Sequence↗
PubMed1994

Localization of motilin-immunopositive cells in the rat intestine by light microscopic immunocytochemistry.

Motilin-immunopositive cells (Mo cells) are known to exist in the upper small intestine of many species including man. However, the possible presence of Mo cells in the rat gastrointestine has remained obscure because antiserum against it raised in rabbit was found not to cross-react with motilin in the rat gastrointestine. The present study was designed to investigate the distribution of Mo cells in the rat gastrointestine by the peroxidase-conjugated second antibody method using newly raised chicken anti-motilin serum (CPV3). This antiserum was suggested to recognize the N-terminal region of the motilin molecule by enzyme-linked immunosorbent assays and immunocytochemical absorption test. Mo cells detected in the rat gastrointestine by immunocytochemistry were found to be distributed in the duodenum (1.5 cells/mm2), jejunum (2.2 cells/mm2), and ileum (0.028 cells/mm2), and no positive cells were found in the gastric body, gastric antrum, cecum, colon, or pancreas. The immunopositive cells in the rat intestine were spindle shaped or polygonal, scattered throughout the epithelium of the villi and crypts, and similar to those commonly observed in the upper small intestine of other species. These results indicate for the first time that motilin-immunopositive cells do exist in the rat intestine.

Animals↗
PubMed1994

Enteroviral RNA in dilated cardiomyopathy.

The exact cause of dilated cardiomyopathy (DCM) remains uncertain. However, a possibility of transition from coxsackievirus-infected myocarditis to DCM has been suspected. We investigated the role of enteroviral infection in the pathogenesis of DCM. The nested reverse transcriptase polymerase chain reaction (nRT-PCR) was used to detect enteroviral RNA in 45 endomyocardial biopsy tissues obtained from 35 patients with DCM and 10 patients (controls) with other non-infectious cardiac diseases. Enteroviral RNA was detected in 17 (49%) of the 35 patients with DCM. The progression to cardiac failure was rapid, usually within 12 months, and myocardial fibrosis and myocytic hypertrophy were marked in patients that were enteroviral RNA positive. Enteroviral RNA was not detected in any controls.

Base Sequence↗
PubMed1994

Acute toxicity of lipiodol infusion into the hepatic arteries of dogs.

RATIONALE AND OBJECTIVES: The authors studied the acute toxicity of percutaneous transcatheter hepatic artery infusion of iodized poppy oil fatty acid ester (Lipiodol, Laboratoire Guerbet, Aulnay-sous-Bois, France). METHODS: Lipiodol dosages of 0, 0.25, 0.5, 1.0, and 2.0 mL/kg were infused into the hepatic arteries of 10 beagles. Enzymatic and radiographic alterations were assessed. RESULTS: After the infusion of Lipiodol, the dogs showed body weight loss and hypoalbuminemia attributable to decreased food intake, transient elevation of the aspartate transaminase and alanine transaminase, and continuous increase in alkaline phosphatase. The controls did not show any significant change. The radiographs obtained immediately after and 2 weeks after the infusion showed dose-dependent accumulation of Lipiodol in the liver. After 2 weeks, histologic examination of livers and lungs showed dose-dependent (r = .9) retention of oily droplets in sinusoids and pulmonary capillaries. Interlobar pericholangitis was found in four dogs infused with Lipiodol. Pulmonary inflammatory reaction was observed with capillary oil embolism. Oil droplets also were found in the pancreas and the brain. CONCLUSIONS: Lipiodol infusion of the hepatic artery resulted in dose-dependent circulation and embolism of Lipiodol droplets via sinusoids and via pulmonary capillaries into the systemic circulation.

Acute Disease↗
PubMed1994

Sequential decrease in tight junctions as revealed by 7H6 tight junction-associated protein during rat hepatocarcinogenesis.

A sequential decrease in the number of hepatocyte tight junctions during the course of rat hepatocarcinogenesis was demonstrated by immunohistochemistry with a new 7H6 monoclonal antibody generated in our laboratory. Semiquantitative analysis by confocal laser scanning microscopy revealed that the expression of 7H6 antigen was reduced in hyperplastic foci, hyperplastic nodules and hepatocellular carcinomas (HCC) to 43%, 28% and 25%, respectively, compared to corresponding normal liver tissues. 7H6 antigen was scarce in HCC with a trabecular pattern, whereas it was expressed intensely at the apical and basolateral membrane of HCC with a glandular pattern. Immunoblot analysis of 7H6 expression in hepatocellular carcinomas showed a decrease roughly coincident with that shown by immunohistochemistry. These results indicated, for the first time, that tight junctions decrease progressively during carcinogenesis, leading to disruption of cellular polarity and cellular adhesiveness.

Animals↗
PubMed1994

Enteroviral RNA in endomyocardial biopsy tissues of myocarditis and dilated cardiomyopathy.

Enteroviruses are potential etiologic agents of myocarditis and dilated cardiomyopathy (DCM). A recently developed molecular approach has offered evidence of viral infection by detecting the virus genome. The nested reverse transcriptase polymerase chain reaction (nRT-PCR) was used to detect enteroviral RNA in endomyocardial biopsy tissues of myocarditis and DCM. The authors examined 44 tissues obtained from 36 patients with myocarditis, as well as from 10 patients with non-infectious cardiac diseases as controls. Enteroviral RNA was detected in 12 of 36 patients with myocarditis. The second endomyocardial biopsy was carried out in five of the patients, in whom enteroviral RNA was detected at the first biopsy, at intervals from 3 weeks to 8 years after the first biopsy, and enteroviral RNA was found in four and had disappeared in one. In one of the four positive patients at the second biopsy, a third biopsy was carried out 5 months later (6 months after the first), and the RNA was detected. Active myocarditis became clinically and microscopically mild at the second and third biopsies. In one patient who developed DCM, enteroviral RNA was also detected at a second biopsy performed 8 years after the first. Enteroviral infection is a probable cause of myocarditis and enterovirus-infected myocarditis may progress to DCM.

Adolescent↗
PubMed1994

Kabuki make-up syndrome associated with chronic idiopathic thrombocytopenic purpura.

Although susceptibility to infections in Kabuki make-up syndrome (KMS) has frequently been reported, there have been few immunological studies. We describe a 14 year old girl with KMS exhibiting chronic idiopathic thrombocytopenic purpura (chronic ITP), including immunological studies. Corticosteroid therapy was not effective therefore splenectomy was performed. The patient's platelet count increased transiently. Immunological studies revealed normal T cell functions and low serum immunoglobulin A (IgA) levels. Because of the abnormalities of B cell functions in chronic ITP and low serum IgA levels in our patient, we speculate that there may be some abnormalities of humoral immunity in KMS.

Adolescent↗
PubMed1994

Immunocytochemical localization of bone morphogenetic proteins (BMPs) in salivary gland pleomorphic adenoma.

The localization of bone morphogenetic protein (BMP)-1, -2, -3 and transforming growth factor (TGF)-beta in normal salivary gland and pleomorphic adenoma of the salivary gland has been examined immunocytochemically. Tumor cells with BMP immunostaining in pleomorphic adenoma were associated with some solid cellular and tubuloglandular patterns, and with stellate cells in the myxoid area. In addition, in the chondroid area of three pleomorphic adenomas, chondrocyte-like cells were positive for BMPs. It is speculated that BMPs secreted by the tumor cells play a role in the formation of the chondroid component in pleomorphic adenoma by inducing some tumor cells, probably neoplastic myoepithelial cells, to differentiate to chondrocytes by metaplastic change. No tumor cells specifically immunostained with TGF-beta were found. TGF-beta was positive in fibrous and hyalinized stroma. In the submandibular gland, only anti-BMP-1 antibody specifically reacted to apical portions of degenerated serous acinar cells.

Adenoma, Pleomorphic↗
PubMed1994

Seroprevalence of hepatitis B and C viruses in eastern Nepal.

The seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) in 303 serum samples collected from that apparently healthy population inhabitating different areas in eastern Nepal was studied. Samples were collected at Dharan Municipality, Sunsari85), Pancha Kanya Village Development Committee, Ilam86), Dhankuta Hile, Dhankuta82) and Basantapur Village Development Committee, Tehrathm50). HBsAg and anti-HBsAg antibody was screened by reverse passive haemagglutination (RPHA) and passive haemagglutination (PHA) respectively and positivity was confirmed by enzyme linked immunosorbent assay (ELISA). Anti-HCV antibody was detected by ELISA. None of the samples were positive for HBsAg. Anti-HBsAg antibody was positive in 1.9% (6/303). The positive rate increased with age reaching 25% positivity among the elderly. The anti-HBsAg antibody positivity was 2.35, 2.32, 1.22 and 2.00 in Dharan, Ilam, Dhankuta and Tehrathum respectively Anti-HCV antibody was detected only in one sample (15-year-old boy) collected in Dharan. These findings indicate that the HBV and HCV infections are not active in eastern Nepal.

Adolescent↗
PubMed1994

Secretion of both partially unfolded and folded apoproteins of dimethyl sulfoxide reductase by spheroplasts from a molybdenum cofactor-deficient mutant of Rhodobacter sphaeroides f. sp. denitrificans.

Spheroplasts prepared from a molybdenum cofactor-deficient mutant of Rhodobacter sphaeroides f. sp. denitrificans secreted dimethyl sulfoxide (DMSO) reductase which had no molybdenum cofactor and therefore no activity, whereas those from wild-type cells secreted the active reductase. The inactive DMSO reductase proteins were separated by nondenaturing electrophoresis into two forms: form I, with the same mobility as the native enzyme, and form II, with slower mobility. Both forms had the same mobility on denaturing gel. Form I and active DMSO reductase had the same profile on gel filtration chromatography. Form II was eluted a little faster than the native enzyme, suggesting that DMSO reductase form II was not an aggregated form but a compactly folded form very similar to the native enzyme. Form II was digested by trypsin and denatured with urea, whereas form I was unaffected, like native DMSO reductase. These results suggested that form II was a partially unfolded but compactly folded apoprotein of DMSO reductase.

Apoenzymes↗
PubMed1994

An expectorant, stepronin, reduces airway secretion in vitro.

Stepronin (SPN) is clinically used as an expectorant, and thenoic acid (TA) is its metabolite. We examined the effects of these drugs on the bioelectric parameters [potential difference (PD), short circuit current (SCC), conductance (G)] of the posterior epithelial membrane of canine trachea and on those of the mucus glycoprotein secretion from feline tracheal isolated glands. PD and SCC were obtained using an Ussing chamber and G was calculated as the ratio SCC/PD. Neither SPN nor TA significantly altered the baseline values of PD and SCC. However, in the mucosal solution, both SPN and TA significantly inhibited PD and SCC evoked by isoproterenol (ISOP), whereas G remained unchanged. Amirolide did not alter the inhibitory action of SPN and TA. Mucus glycoprotein secretion from isolated glands was estimated by measuring trichloride acetic acid-precipitable [3H]-glycoconjugates. SPN and TA significantly reduced mucus glycoprotein secretion. Further, when stimulated by methacholine, these agents significantly inhibited mucus glycoprotein secretion from isolated glands. These findings suggest that SPN inhibits airway secretion in vitro by both decreasing Cl- secretion from epithelial cells and mucus glycoprotein secretion from submucosal glands.

Amiloride↗
PubMed1994

Viral respiratory infection causes airway hyperresponsiveness and decreases histamine N-methyltransferase activity in guinea pigs.

We investigated the effects of viral respiratory infection by Sendai virus on bronchial responses to aerosolized histamine in anesthetized guinea pigs and on the activity of histamine N-methyltransferase (HMT). We measured the change in total pulmonary resistance induced by histamine in the presence or absence of a specific HMT inhibitor, SKF 91488, in noninfected and infected animals. In the absence of SKF 91488, the bronchoconstrictor response to histamine was greater in infected than in noninfected animals. SKF 91488 (10(-2) M, 90 breaths) potentiated the responses to histamine in noninfected animals, and the magnitude of augmented responses to histamine by SKF 91488 was similar to that by viral infection. Furthermore, SKF 91488 did not further potentiate the responses to histamine in infected animals. However, responses to aerosolized acetylcholine were unaffected by viral infection and SKF 91488. The HMT activity decreased by 56% in the trachea, 86% in the bronchi, and 52% in the parenchymal tissue in the infected animals. In contrast to HMT activity, acetylcholinesterase activity was unaffected by viral infection. These results suggest that respiratory infection by Sendai virus causes enhanced bronchial responsiveness to histamine by decreasing HMT activity in airways.

Acetylcholine↗
PubMed1994

Autoantibodies to RNA polymerase II are common in systemic lupus erythematosus and overlap syndrome. Specific recognition of the phosphorylated (IIO) form by a subset of human sera.

Autoantibodies to RNA polymerases (RNAP) I, II, and III are reported to be highly specific for the diagnosis of scleroderma (systemic sclerosis, SSc). In the present study, the specificity of autoantibodies to RNAP I and III for SSc was confirmed by immunoprecipitation of 35S-labeled proteins. However, we report here the previously unrecognized production of anti-RNAP II autoantibodies by 9-14% of patients with SLE and mixed connective tissue disease/overlap syndrome. 12 out of 32 anti-RNAP II positive sera (group 1) immunoprecipitated a diffuse 220-240-kD band identified as the largest subunit of RNAP II whereas the remaining 20 (group 2) immunoprecipitated preferentially the 240-kD phosphorylated (IIo) form of the large subunit. After pulse labeling, group 1 sera immunoprecipitated only the 220-kD (IIa) RNAP II subunit, whereas the diffuse IIa/IIo band plus the 145-kD second largest RNAP II subunit (IIc) were immunoprecipitated after several hours of cold chase, suggesting that these sera recognized primarily the largest subunit of RNAP II. Group 2 sera recognized the IIc subunit after pulse labeling, and immunoprecipitated the IIc and IIo, but not the IIa, subunits after cold chase. Although it has been suggested that autoantibodies to RNAP II are usually accompanied by anti-RNAP I/III in SSc, all but one of the anti-RNAP II positive sera from SLE or mixed connective tissue disease/overlap syndrome patients, as well as most of the SSc sera, were negative for anti-RNAP I/III. Moreover, in contrast to previous reports suggesting that anti-RNAP antibodies rarely coexist with other SSc subset marker antibodies, anti-RNAP II antibodies were often accompanied by anti-Ku, anti-nRNP, or anti-topoisomerase I autoantibodies in the present study. We conclude that autoantibodies to RNAP II are not a specific marker for SSc, whereas autoantibodies to RNAP I/III are associated primarily with SSc. In addition, we have identified two distinctive patterns of RNAP II antigen recognition by autoantibodies, one of them characterized by specific recognition of the transcriptionally active (phosphorylated) form of RNAP II. The clinical significance of these different patterns remains to be determined.

Adult↗
PubMed1994

Recurrent annular erythema with anti-SSA/Ro and anti-SSB/La antibodies localized on palms and fingers in an elderly man.

A 69-year-old Japanese man with recurrent annular erythema localized on palms and flexor surface of fingers with anti-SSA/Ro and anti-SSB/La antibodies, is reported. The present case indicates that even in an elderly man with atypical localization, annular erythema with autoimmunity may be considered and serological analysis should be performed. Systematic studies will be required to understand the relationship between 'recurrent annular erythema associated with anti-SSB/La antibodies' in Japanese, subacute cutaneous lupus erythematosus (SCLE) and 'annular erythema associated with Sjogren's syndrome'.

Aged↗
PubMed1994

Chronic eosinophilic pneumonia progressing to lung fibrosis.

A 65 year old Japanese man was hospitalized with fever. Opacities distributed mainly in the subpleural regions were found on chest computed tomographic scan (CT), and these promptly cleared with corticosteroid therapy. Four years later, he presented with severe eosinophilia. Both chest X-ray and high resolution CT scan showed ground-glass opacities and honeycombing, suggesting lung fibrosis. A lung biopsy demonstrated intra-alveolar eosinophil infiltration, interstitial thickening with eosinophil infiltration, and a widely-distributed desquamative interstitial pneumonia-like reaction. With corticosteroid therapy, the ground-glass opacities decreased with a corresponding clinical improvement, although lung honeycombing and blood eosinophilia remained. In this case, circulating intercellular adhesion molecule-1 and circulating and bronchoalveolar lavage fluid eosinophil granule proteins were felt to be more effective markers for evaluating disease activity than the blood eosinophil number.

Aged↗