Biomedical subjects

J Tomoda

Publications and source records attributed to J Tomoda.

At least 19 recordsLinked to original sources

PubMed1997

Immunohistochemical analysis of intercellular adhesion molecule-1 expression in human gastric adenoma and adenocarcinoma.

In this study, we examined the distribution of intercellular adhesion molecule-1 (ICAM-1) in gastric adenomas and carcinomas immunohistochemically at the light and electron microscopic levels. ICAM-1 was expressed on tumour cells in 12 of 28 gastric carcinomas and in 3 of 11 adenomas but not on most normal gastric epithelial cells. ICAM-1 was localized on luminal sites of neoplastic glands in adenomas and in intestinal-type carcinomas, and rarely on the surface of tumour cells of diffuse carcinomas. Expression of ICAM-1 on the tumour cells was more frequent in intestinal-type than diffuse carcinomas (P < 0.005). At the ultrastructural level, ICAM-1 was present prominently on the apical membrane and weakly on the lateral surface of the tumour cells of the intestinal-type carcinoma and also localized on the perinuclear membrane and the membrane of the endoplasmic reticulum of cancer cells. There was no significant association between ICAM-1 expression and HLA antigen expression or the number of infiltrating lymphocyte subsets. These results may implicate the synthesis of ICAM-1 by gastric cancer cells, but the expression is infrequent and may not be sufficient for host immune surveillance of the tumour cell.

Adenocarcinoma↗

PubMed1997

Assessment of UDP-galactosyl-transferase activity in gastric mucosa of patients with chronic liver disease using an enzyme-linked peanut agglutinin binding assay.

Gastric mucin plays an important role in protecting mucosa from irritants such as acids and pepsin, and UDP-galactosyltransferase is a key enzyme in mucin synthesis. In order to study the synthesis of gastric mucin in patients with chronic liver disease, we developed a new assay using a peanut agglutinin lectin to measure this enzyme in human gastric mucosa obtained by endoscopic biopsy. Enzyme activity correlated well with that determined with a previous method using radiolabeled galactose. The enzyme activity in gastric mucosa of cirrhotic patients was significantly lower than in patients with chronic hepatitis or in normal controls and correlated with the amount of mucin in surface epithelial cells. Our findings suggest that the synthesis of gastric mucin is impaired in patients with liver cirrhosis.

Adult↗

PubMed1996

Epithelial cell proliferation during colonic chemical carcinogenesis in the rat.

To define the significance of alterations in epithelial cell proliferation as a marker of high risk mucosa for colorectal cancer, we examined cell proliferative events in the colonic mucosa during chemical carcinogenesis using in vitro bromodeoxyuridine labelling and by analysing serial colonoscopic biopsy specimens from dimethylhydrazine (DMH)-treated rats. In both the rectum and flexure of the colon, an increased labelling index of colonic epithelial cells, an upward extension of the proliferating zone and an upward shift of the major area of DNA synthesis of epithelial cells were observed during DMH-induced colonic carcinogenesis in rats. These changes preceded the development of the colonic tumour and were observed in endoscopically normal rectal mucosa where the tumour was absent. We confirmed the altered cell proliferative events preceding the development of the tumour by examining serial colonoscopic biopsies. The results suggest that these alterations are features that identify premalignant colonic mucosa in DMH-treated rats.

Animals↗

PubMed1995

Flow cytometric analysis of the DNA content in colorectal adenomas with focal cancers.

BACKGROUND & AIMS: Variable results have been reported on the nuclear DNA content of colorectal polyps. The significance of DNA aneuploidy in the malignant transformation of colorectal polyps was evaluated. METHODS: We analyzed by flow cytometry the nuclear DNA content of freshly frozen samples of 50 colorectal adenomas with or without focal cancers, analyzing separately the adenomatous and cancerous regions of the polyps. RESULTS: In the adenomatous regions of the 50 polyps, the DNA was diploid in 43 and aneuploid in 7; the adenomas with DNA aneuploidy in the adenomatous regions were more frequently accompanied by focal cancers than were the DNA-diploid adenomas (P < 0.01). In 60% of the polyps with DNA aneuploidy in the cancerous regions, the DNA was also aneuploid in the adenomatous region and had similar DNA indices; this result suggests that the DNA aneuploidy had already occurred during the adenomatous stage, which lends support to the concept of the adenoma-carcinoma sequence. DNA aneuploidy in the adenomatous region was significantly correlated with the size of colorectal polyps (P < 0.05). CONCLUSIONS: DNA aneuploidy may be an important indicator for the early diagnosis of malignant transformation of colorectal polyps.

Adenoma↗

PubMed1995

Enhanced expression of decay accelerating factor and CD59/homologous restriction factor 20 on the colonic epithelium of ulcerative colitis.

BACKGROUND: The complement system is thought to be one of the factors involved in damaging the colonic mucosa in the pathogenesis of ulcerative colitis (UC). Several membrane-bound factors that regulate complement activation have been identified. EXPERIMENTAL DESIGN: To elucidate alteration(s) of the complement regulatory proteins and to add to the understanding of the role of the complement-related immune responses in the pathogenesis of UC, we immunohistochemically examined the distribution of decay accelerating factor (DAF), CD59/homologous restriction factor 20 (HRF20), and membrane cofactor protein (MCP) in colonic mucosa with UC and compared it with that in normal and inflammatory control mucosae. RESULTS: In normal colonic epithelia, the cell surface distribution of DAF and CD59/HRF20 was confined to the apical domain, whereas MCP was present on the basolateral surface. Although MCP expression in active UC was not significantly different from normal mucosa, DAF and CD59/HRF20 expression on epithelial cells of UC was markedly enhanced in relation to the severity of mucosal inflammation. In the colonic epithelia of active UC, DAF and CD59/HRF20 were not only overexpressed on the apical surface but also were distributed to the basolateral membrane. The altered cell surface distribution of these molecules was also confirmed by immunoelectron microscopy. The enhanced expression of DAF and CD59/HRF20 was not specific to UC but was observed in colonic mucosa of inflammatory controls, such as ischemic colitis. CONCLUSIONS: Our results indicate that altered regulation of complement activation is present in UC mucosa, but whether it may play a causal role in the immunologic disorders leading to UC remains to be elucidated.

Adult↗

PubMed1994

Immunohistochemical analysis of epithelial cell proliferation in normal-appearing rectal mucosa of patients with colorectal adenoma and cancer using an in vitro labeling method with bromodeoxyuridine.

To identify diffuse mucosal changes which may precede the development of colorectal cancer and a possible indicator for detecting high-risk populations, we immunohistochemically studied cell-cycle events in crypts of normal-appearing rectal mucosa of patients with colorectal adenoma and cancer using an in vitro labeling method with bromodeoxyuridine (BrdU). Biopsy specimens of endoscopically normal-appearing rectal mucosa were obtained during colonoscopy from 20 patients with colorectal adenocarcinoma, 20 with adenoma, and 15 without apparent colorectal diseases. The specimens were incubated with BrdU in vitro, and labeled S-phase cells were identified immunohistochemically using a monoclonal antibody to BrdU. Modification of the BrdU-labeling pattern in the normal appearing rectal mucosa, such as the presence of BrdU-labeled cells at the mucosal surface or in the upper one-fifth of the crypt column, was observed in 15 of the 20 patients with adenocarcinoma, 17 of the 20 patients with adenoma and 6 of the 15 controls. This upward shift in the frequency of proliferating cells in the crypt was significantly higher in the patients with colorectal adenoma and cancer than in the controls, and may be used to identify subjects at high risk for colorectal cancer.

Adenoma↗

PubMed1994

Endoscopical segmental piecemeal tumorectomy for nodular elevation of colorectal tumor: applicability and patient's quality of life.

Endoscopical segmental piecemeal tumorectomy (ESPT) for nodular elevation of colorectal tumor is advantageous in terms of minimizing both surgical invasion and postoperative burden to the patients. Nodular elevation of colorectal tumors is said to occur when the body of the tumor is adenomatous and the surface of the focal cancer grows more horizontally into the lumen than vertically. We report here four cases of nodular elevation of colorectal tumors which were each treated by different surgical procedures.

Aged↗

PubMed1993

Prominent telangiectasia associated with marked bleeding in CREST syndrome.

A 64-year-old woman with CREST syndrome developed prominent telangiectases mimicking hereditary hemorrhagic telangiectasia (HHT) of Osler-Rendu-Weber. We have been following her since she first came to us with discrete telangiectatic mats and Raynaud's phenomenon 11 years ago. Telangiectatic lesions have been seen on her larynx and esophagus in addition to commonly affected sites. She has experienced spontaneous epistaxis and marked bleeding from the lesions on her lips, oral mucous membrane, and soles. This case illuminates new aspects of telangiectasia in CREST syndrome.

Calcinosis↗

PubMed1993

Malignant pheochromocytoma with hepatic metastasis diagnosed 20 years after resection of the primary adrenal lesion.

A 59-year-old woman developed multiple hepatic tumors 20 years after resection of pheochromocytoma of the left adrenal gland. Thin-needle aspiration biopsy of the tumor at segment 2 of the liver under ultrasound control showed histology compatible to pheochromocytoma. Then, on the basis of the diagnosis of hepatic metastasis of malignant pheochromocytoma, transcatheter arterial embolization (TAE) was performed for the purpose of the treatment of hepatic metastasis. After TAE, the size of the hepatic metastatic lesions was decreased. The present case suggests the necessity of long-term follow-up in pheochromocytoma cases.

Aclarubicin↗

PubMed1991

Analysis of galactosyltransferase activity in rat gastric mucosa using crude mucosal homogenate.

Mucus glycoprotein is one of the major components of gastric mucus which plays an important role in mucosal defensive mechanisms as a mucus-bicarbonate barrier. Analysis of the mucus glycoprotein synthesis is a useful tool for evaluating gastric mucosal defensive factors. UDP-galactosyltransferase (UDP-Gal-T) is one of the regulating enzymes for the synthesis of the mucus glycoprotein. In the present paper, we studied assay methods for UDP-Gal-T activity in rat gastric mucosa using radiolabeled UDP-galactose and two different kinds of acceptor proteins, namely ovomucoid and asialomucin, and analyzed effects of antisecretory agents on the UDP-Gal-T activity. We used crude supernatants of homogenized scrapings of the fundic part of rat stomach as an enzyme preparation and determined optimal conditions. In each acceptor, Mn2+ and the non-ionic detergent Triton X-100 were required for the enzyme activity. With each acceptor molecule, the type of glycosidic linkages of galactose was beta-type linkage. With asialomucin as an acceptor, UDP-Gal-T activities of rat gastric mucosa decreased after intraperitoneal administration of antisecretory agents, while change of the enzyme activity was not observed with ovomucoid as an acceptor.

Animals↗

PubMed1989