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Biomedical subjects

M Otaka

Publications and source records attributed to M Otaka.

At least 19 recordsLinked 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

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

Incidental detection of breast cancer during T1-201 myocardial SPECT study.

A case of left breast cancer which was detected incidentally by T1-201 SPECT performed to evaluate the status of myocardial perfusion, is reported. Both stress and redistribution T1-201 SPECT clearly delineated the tumor. It was confirmed later as scirrhous carcinoma of the breast.

Adenocarcinoma, Scirrhous↗
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↗
PubMed1994

Regulation of 60-kDa heat shock protein expression by systemic stress and 5-hydroxytryptamine in rat colonic mucosa.

Bowel dysfunction such as irritable bowel syndrome caused by stress is well described. Previous reports suggest that 5-hydroxytryptamine (5-HT) mediates alteration of bowel motility. In this study, the effects of water-immersion stress and the administration of 5-HT on the expression of a 60-kDa heat shock protein (HSP60) in rat colonic mucosa were investigated. The effect of YM-060, a 5-hydroxytryptamine 3 (5-HT3) receptor antagonist, on the expression of this protein was also studied. Water-immersion stress and the administration of 5-HT induced synthesis of HSP60 in rat colonic mucosa. The induction of HSP60 and the number of defecations were clearly inhibited by the oral administration of YM-060. Our results suggest that the induction of HSP60 in rat colonic mucosa by water-immersion stress may be associated with gastrointestinal motility mediated by 5-HT, especially via 5-HT3 receptors.

Animals↗
PubMed1994

A case of toxic megacolon in ulcerative colitis associated with cytomegalovirus infection.

Cytomegalovirus (CMV) infection, which has been shown to complicate the course of ulcerative colitis (UC), has been implicated as a possible etiologic factor in the exacerbation of UC, especially in toxic megacolon. However, CMV infection in patients with UC accompanied by toxic megacolon has rarely been reported. Here we report a case of CMV infection of the colon accompanied by toxic megacolon occurring in UC. A 38-year-old woman had been treated with intravenous hydrocortisone, rectal steroid, and central venous alimentation for 6 weeks under the diagnosis of UC. She was transferred to Akita University Hospital because of increasing bloody diarrhea and abdominal pain. Toxic megacolon was identified by examinations on admission, and she underwent a total colectomy. Examination of the surgical specimen showed severe inflammation of the colon. Microscopically, cytomegalic inclusions were observed in and around the endothelial cells in the inflamed submucosal layer. It can be assumed that CMV infection was a secondary, opportunistic invader superimposed on UC, and that it played an important role in altering the clinical course of the patient.

Adult↗
PubMed1994

Induction of heat shock protein and prevention of caerulein-induced pancreatitis by water-immersion stress in rats.

Water-immersion stress is known to be involved in the development of hemorrhagic pancreatitis in caerulein-induced pancreatitis, when the stress is given following caerulein injection. The effects of pre-treatment with water-immersion to caerulein-induced pancreatitis were investigated in this study. 1. A 60-kDa heat shock protein was induced by pre-treatment with water-immersion stress in the pancreas. 2. Intra-peritoneal injection of caerulein (40 micrograms/kg) induced acute pancreatitis in rats without pre-treatment with water-immersion. However, when the rats were pre-treated with water-immersion, acute pancreatitis was not developed and no change of serum amylase levels was observed by i.p. injection of caerulein.

Amylases↗
PubMed1994

Electronic endoscopy in perspective.

Electronic endoscopy, developed in 1983, enables the endoscopic image to be transmitted through electric signals that can be easily processed by computer. An electronic endoscope is composed of three vital parts, i.e., a charge-coupled device (CCD) that converts the image to electric signals, a video processor that converts analog electric signals to the digital and processes them to become video signals, and a television monitor. The introduction of electronic endoscopy has enabled computer management of endoscopic images, on one hand, and provided an opportunity for image processing and analysis, on the other. A digital image management system will further develop into a database of endoscopic images. Combined with the technologies of remote control and remote sensing, the introduction of CCD to endoscopy has made it possible to transform the endoscope, so that it could become a capsule. Future advances in the research of image processing and analysis will lead to the development of a system of automated endoscopic diagnosis.

Electronics, Medical↗
PubMed1993

Induction of a 60-kDa heat shock protein in rat pancreas by water-immersion stress.

1. In this study, expression of a 60-kDa heat shock protein in rat pancreas was investigated before and after water-immersion stress, which has been known as an exacerbation factor of caerulein-induced pancreatitis in rats, by Western blot. 2. A 60-kDa heat shock protein increased after water-immersion stress in both soluble and insoluble fractions of the pancreas. 3. Serum amylase level and pancreas weight did not increase after water-immersion. 4. No pathologic alteration was observed in the pancreas after water-immersion.

Animals↗
PubMed1989

Antibody-mediated targeting of differentiation inducers to tumor cells: inhibition of colonic cancer cell growth in vitro and in vivo. A preliminary note.

A differentiation inducer (sodium butyrate) encapsulated in liposomes that are in turn covalently linked to anti-Lex monoclonal antibody, SH1 (IgG3 isotype), was successfully targeted to human colonic adenocarcinoma HRT-18 and HT29 cells expressing Lex antigen in vitro as well as in vivo in athymic nu/nu mice. Tumor cell growth was significantly inhibited and was associated with changes in cell morphology and increases in membrane-bound alkaline phosphatase and gamma-glutamyltranspeptidase, indicating the occurrence of butyrate-induced differentiation.

Adenocarcinoma↗