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O Masamune

Publications and source records attributed to O Masamune.

At least 73 records · Page 4Linked to original sources
PubMed1995

Mammalian 60-kDa stress protein (chaperonin homolog). Identification, biochemical properties, and localization.

Mammalian chaperonin homolog (HSP60) was purified from porcine livers cytosol using a tandem ATP-Sepharose column and Mono Q column chromatography. A partial amino acid sequence (96 amino acid residues) of this protein was determined and coincided with those of human HSP60 with 96.9% homology, which was deduced from the nucleotide sequence of the cDNA. The sequence of the NH2 termini of the purified protein (5 amino acid residues) coincided with the signal sequence of HSP60. These facts led to the identification of the 60-kDa liver protein with the chaperonin homolog. Dihydrofolate reductase was able to form a stable complex with the liver chaperonin homolog. The liver chaperonin homolog was detected by at least five spots around pI = 5.6 on two-dimensional gel electrophoresis. Immunoblotting studies using an antibody against chaperonin homolog showed that the chaperonin homolog was localized in the cytosol, mitochondrial, and nuclear fractions of porcine liver. The chaperonin homolog was localized both in the mitochondria and cytoplasm of rat kidneys at the electron microscopic level. The chaperonin homolog in the cytosol, but not in the other subcellular fractions, was cross-reacted with an antibody against the synthetic peptide corresponding to the signal peptide of HSP60 as well as the purified chaperonin homolog on immunoblotting. These results suggested that the functional chaperonin homolog in the cytosol may be transported into the mitochondria and the protein may be processed to mitochondrial HSP60 in the organella.

Amino Acid Sequence↗
PubMed1995

Topographic study of Helicobacter pylori and HLA-DR antigen expression on gastric epithelium.

Helicobacter pylori and HLA-DR antigen expression on gastric epithelium, identified by an indirect immunoperoxidase staining method using monoclonal antibodies against H. pylori and HLA-DR antigens, were studied topographically. Fifty-nine biopsy specimens from 41 patients who had neither gastric cancer nor peptic ulcers were examined. H. pylori was observed predominantly over or on the surface epithelium, while HLA-DR antigens were frequently expressed on the epithelium of the isthmus region. These observations led to the conclusion that there was no direct topographic association between H. pylori and epithelial HLA-DR expression. However, the frequency of HLA-DR expression in H. pylori-positive (28/29) specimens was significantly higher than that in H. pylori-negative (18/30) specimens (P < 0.01). Furthermore, a greater number of H. pylori was associated with a stronger expression of HLA-DR antigens (P < 0.001). We conclude that H. pylori is indirectly related to HLA-DR expression on gastric epithelium. H. pylori is the first microbial agent that has been suggested to be associated with epithelial HLA-DR expression in the human gastrointestinal tract.

Adolescent↗
PubMed1995

Induction and intracellular localization of a 72-kDa heat shock protein in rat gastric mucosa after water-immersion stress.

We investigated the expression and changes in the intracellular localization of a 72-kDa heat shock protein (HSP72) in rat gastric pyloric and fundic mucosa before and after water-immersion stress. Severe mucosal damage was found in the fundic mucosal area of the stomach after this stress. However, no mucosal lesion developed in the pyloric mucosal area. HSP72 in both the soluble and insoluble fractions of the pyloric and the fundic mucosal areas was significantly increased after water-immersion stress, peaking 6h after the initiation of the stress. The increase in HSP72 was more significant in the pyloric mucosal area than in the fundic mucosal area under both normal and stress conditions. The increase of HSP72 in the pyloric mucosal cells occurred prior to the formation of the mucosal lesions, whereas the increase of HSP72 in the fundic mucosal cells was observed after ulcer formation. An immunohistochemical study showed that HSP72 was constitutively expressed in the cytoplasm of the gastric mucosal cells, and that the intranuclear induction of HSP72 was remarkably intense in the pyloric mucosal cells, especially in the proliferative zone, compared with the fundic mucosal cells. Our results may suggest that HSP72 has an important cytoprotective function in gastric mucosal cells and that there is a "biophysical" difference between pyloric and the fundic mucosal cells.

Animals↗
PubMed1995

Purification and characterization of cytoplasmic dynein of rabbit liver.

Cytoplasmic dynein is a microtubule-dependent motor protein, which plays a role in intracellular transport. However, there have been few studies regarding the role of cytoplasmic dynein in the liver. Purification of cytoplasmic dynein from rabbit liver took advantage of the affinity of microtubule-dependent motor proteins for microtubules. Purified dynein contained heavy chain (450 kDa), intermediate chain (75 kDa), light chains (45-58 kDa) and dynactin (150 kDa). The subunit composition was consistent with previously reported data on brain cytoplasmic dynein. Microtubules prepared from bovine brain were driven by purified cytoplasmic dynein from rabbit liver, and movements of microtubules were visualized by video-enhanced differential interference contrast microscopy. The mean velocity of the motile microtubules was 1.09 +/- 0.13 microns/s. Our study provides evidence of rapid intracellular transport in hepatocytes controlled by cytoplasmic dynein.

Animals↗
PubMed1995

Novel colorectal adenocarcinoma-associated 40- and 47-kDa protein antigens recognized by anti-60-kDa heat shock protein antibody.

Expression of 40- and 47-kDa proteins recognized by anti-60-kDa heat shock protein antibody was investigated in colorectal adenocarcinoma tissue. In all cases of colorectal adenocarcinoma tissue (n = 9), 40- and 47-kDa proteins were detected by immunoblot analysis. However, expression of these two proteins was extremely low or was not expressed in control tissue. There was no correlation between the quantity of these two bands and histologic type or the location of the tumors. Our results first demonstrate the accumulation of structurally altered 60-kDa heat shock protein-associated antigens in carcinoma tissue and suggest that these two proteins could be a possible candidate for tumor-specific 60-kDa heat shock protein-related protein antigens.

Adenocarcinoma↗
PubMed1995

Further studies of HLA-DR antigens on colonic epithelium in ulcerative colitis.

The aim of this study was to determine whether HLA-DR antigens are expressed on colonic epithelium in macroscopically involved areas in all cases of ulcerative colitis and whether the expression precedes inflammation (colitis). Thirty-four cases of active ulcerative colitis were studied including two cases in which island-like lesions were observed proximally apart from the main lesion, and three cases in which distal colitis became entire colitis in 8 months or less. Detection of HLA-DR antigens on colonic epithelium was performed with the immunoperoxidase method using anti-HLA-DR monoclonal antibodies. HLA-DR antigens were expressed on colonic epithelium in macroscopically involved areas in all 34 cases. In the macroscopically normal areas, the antigens were modestly expressed in six of 16 specimens (cases) in the presence of microscopic inflammation. The antigens were expressed on colonic epithelium in island-like lesions, but not in the intervening mucosa between the proximal island-like lesions and the distal main lesion. HLA-DR antigens were not expressed on colonic epithelium in the proximal non-inflamed mucosa where colitis later developed. These results lead to the conclusion that HLA-DR antigen expression does not precede, but is associated with the inflammation.

Adolescent↗
PubMed1995

Primary lymphoma of the spleen with hepatocellular carcinoma.

This is the first reported case of primary lymphoma of the spleen coexisting with primary hepatocellular carcinoma. A 59-year-old woman was admitted to Ugo town hospital because of general malaise. Physical examination revealed no lymphadenopathy. Laboratory data showed mild anemia, thrombocytopenia, and slight elevation of alpha-fetoprotein (AFP). Ultrasonography of the abdomen revealed a mass in the left lobe of the liver and a mass in the splenic hilus. The liver tumor was presumed to be a primary liver cancer. Ultrasonically guided needle aspiration of the splenic mass was unsuccessful. Subsequently, the patient died of hepatic and renal failure. Autopsy revealed hepatocellular carcinoma and primary splenic non-Hodgkin's lymphoma of the diffuse large cell type.

Carcinoma, Hepatocellular↗
PubMed1995

Ruptured subcapsular giant hematoma of the spleen as a complication of chronic pancreatitis.

We present a 63-year-old man with chronic pancreatitis and the rare complication of giant subcapsular splenic hematoma. The hematoma showed no size reduction for 6 weeks. Then, the hematoma was infected with pseudomonas aeruginosa after the recurrence of the pancreatitis, and it finally ruptured. This case suggested that in cases of giant subcapsular splenic hematoma with chronic pancreatitis reductive pressure treatment should be administered as early as possible.

Chronic Disease↗
PubMed1995

Hepatic involvement in Osler-Weber-Rendu disease: findings on pulsed and color Doppler sonography.

OBJECTIVE: The purpose of this study was to compare the hemodynamics of the liver vasculature as determined by Doppler sonography for patients with Osler-Weber-Rendu disease and for healthy subjects. SUBJECTS AND METHODS: Real-time color Doppler sonography and pulsed Doppler sonography were used to study 10 patients with Osler-Weber-Rendu disease and 25 healthy subjects. Vessel diameter and flow velocity in the hepatic artery and its branches as well as in the portal vein and its segmental branches were determined. Flow patterns in the hepatic veins were analyzed. The clinical manifestations of the disease were correlated with the Doppler sonographic findings. RESULTS: The hepatic artery and its branches were dilated and tortuous, and flow velocity was greater in patients than in healthy subjects; hepatic artery velocities (mean +/- SD) were 153 +/- 65.2 cm/sec versus 64.9 +/- 11.4 cm/sec (p < .005). The resistive index measured in the hepatic artery did not differ significantly between the two groups (p was not significant). No intrahepatic arteriovenous shunt sites were detected by color Doppler sonography. However, arterioportal shunts were observed in two patients, one of whom also had a portovenous shunt. A portovenous shunt and multiple shunts between hepatic veins were found in another patient. Portal venous flow was similar in both groups. No relationship between Doppler sonographic changes and clinical manifestations was found. CONCLUSION: The multiple microscopic arteriovenous shunts found in Osler-Weber-Rendu disease were not detected in our patients but resulted in dilatation and increased flow velocity in the hepatic artery. Flow velocity in the portal vein appeared to be undisturbed. Large intrahepatic shunts were easily outlined by Doppler sonography.

Adult↗
PubMed1995

Clinical characteristics of hepatitis C virus-associated retinopathy.

The morbidity rate for retinopathy of unknown origin was significantly higher (P < 0.001) in the chronic hepatitis C group, 27 (31.8%) of 85 cases, than in the control group, 6 (6.0%) of 100 cases. Among hepatitis C virus (HCV)-associated retinopathy patients, 6 cases (22.2%) were aware of ocular subjective symptoms, retinopathy recurred in 8 (29.6%) cases, binocular retinopathy occurred in 14 (51.9%) cases, and retinopathy related to liver dysfunction, in 13 (81.3%) of 16 tested cases. HCV-associated retinopathy involved hemorrhage at the posterior pole retina in 21 (77.8%), cotton-wool patches in 9 (33.3%), and hemorrhage at the peripheral retina in 7 (25.9%) cases. Sequelae occurred in only one case. Retinopathy worsened or recurred in all 7 cases treated with interferon. The risk factors for HCV-associated retinopathy were mild thrombocytopenia (P < 0.001), long-term hepatitis illness (P < 0.005), advanced age (P < 0.02), concurrence with liver cirrhosis (P < 0.02), history of systemic hypertension (P < 0.05), and female gender (P < 0.05).

Adult↗
PubMed1994

Serotype G6 human rotavirus sharing a conserved genetic constellation with natural reassortants between members of the bovine and AU-1 genogroups.

Serotype G6 human rotavirus PA151 was examined by RNA-RNA hybridization in comparison with another G6 strain PA169 and two naturally-occurring G3 reassortants PCP5 and MZ58. PA151 possessed three gene segments that formed hybrids with AU-1 and seven gene segments that formed hybrids with bovine rotavirus NCDV. PA151 also possessed eight, 10 and 10 gene segments that formed hybrids with genomic RNAs from PA169, PCP5, and MZ58, respectively. Thus, PA151 was an intergenogroup reassortant formed in nature between members of the bovine and AU-1 genogroups and it shared a genome constellation with PA169, PCP5, and MZ58. These results suggest that naturally-occurring intergenogroup reassortants possessing such a genome constellation were perpetuated in human populations.

Animals↗