PubMed Health⌕ Search

Biomedical subjects

Toshifumi Hibi

Publications and source records attributed to Toshifumi Hibi.

At least 55 records · Page 3Linked to original sources
PubMed2005

High expressions of caveolins on the proliferating bile ductules in primary biliary cirrhosis.

AIM: An increase in bile ductular structures is observed in diverse human liver diseases, especially in primary biliary cirrhosis (PBC). These structures harbor the progenitor cell component of the liver. Caveolins are cholesterol-binding proteins involved in the regulation of several intracellular processes including cholesterol transport. This study aims to examine the role of caveolin in PBC. METHODS: Immunohistochemical and Western blotting studies were performed on human liver specimens obtained from patients with PBC and normal liver samples. The expression of caveolin (CAV)-1 and -2 was determined using specific antibodies. RESULTS: In normal liver, scanty immunostaining for CAV-1 and -2 was observed in bile ductules. In PBC liver samples, the expression levels of CAV-1 and -2 were increased on proliferating bile ductules especially in stage 3 cases, but was sparse on interlobular bile duct in stage 1 specimens. Especially, the regenerating bile ductules at the interface of portal tracts and necrotic areas were immunostained intensely for CAV-1 and -2. These phenomena were confirmed by Western blot. CONCLUSION: The present results demonstrate increased expression of caveolins in proliferating bile ductules in PBC, which may be related to the homeostasis of cholesterol transport in regenerating bile ductules in PBC liver.

Adult↗
PubMed2005

Retinoic acid formation from retinol in the human gastric mucosa: role of class IV alcohol dehydrogenase and its relevance to morphological changes.

Alcohol dehydrogenase (ADH) participates in the formation of retinoic acid from retinol in various organs including the gastric mucosa. However, its clinical significance still remains to be clarified. In this study, we identified the ADH isoforms responsible for the retinoic acid formation among various ADH isoforms and examined associations among the ADH activities, the retinoic acid formation level, and morphological changes in the human gastric mucosa. Human gastric samples were endoscopically obtained from 67 male subjects. Morphological changes were assessed by the Sydney system and activities of class I, III, and IV ADH isoforms were determined in each specimen. In 26 cases, levels of all-trans retinoic acid (ATRA) formation from all-trans retinol were examined. Among activities of the three ADH isoforms, class IV ADH activity was solely associated with the ATRA formation level. This association was found even when subjects' age and Helicobacter pylori infection status were adjusted. As the degrees of inflammation, atrophy, and intestinal metaplasia increased, the class IV ADH activity as well as the potential for the ATRA formation decreased. Class IV ADH is a major enzyme in the retinoic acid supply in the human gastric mucosa, and the reduction of its activity was associated with decreasing retinoic acid supply and progression of inflammation, atrophy, and intestinal metaplasia in the gastric mucosa. In that retinoic acid is a key molecule for maintaining normal morphology, the reduction of class IV ADH activity may be involved in the pathogenesis of these morphological changes in the human gastric mucosa.

Alcohol Dehydrogenase↗
PubMed2005

Enhanced ghrelin secretion in rats with cysteamine-induced duodenal ulcers.

Ghrelin, produced and secreted by the A-like cells of the stomach, stimulates growth hormone secretion, gastric motility, and food intake. Cysteamine inhibits the release of somatostatin and induces the formation of duodenal ulcers in rats. The present study was conducted to investigate the dynamics of ghrelin secretion in rats treated with cysteamine. Male Wistar rats (7 wk old) were administered three doses of cysteamine (400 mg/kg) orally; at 50 h after the first dose, duodenal ulcers were induced, and the plasma level of somatostatin and gastric density of somatostatin-immunoreactive cells were significantly reduced. The plasma total and active ghrelin levels were significantly higher in the cysteamine-treated rats than in the control rats, whereas the gastric ghrelin levels, number of gastric ghrelin-immunoreactive cells, and preproghrelin mRNA expression levels were significantly lower. Even at the time points of 2 and 10 h after the first dose of cysteamine, at which time no significant ulcer formation or antral neutrophil accumulation was yet noted, a significant increase in the plasma ghrelin level and decrease in the gastric ghrelin level were observed. Furthermore, although lansoprazole treatment attenuated the duodenal ulceration induced by cysteamine, the increase in the plasma level of ghrelin could still be demonstrated. Because an inverse correlation was found between the plasma ghrelin and somatostatin levels, the inhibition of somatostatin secretion may be associated with the increased ghrelin secretion. In conclusion, an increase in the plasma ghrelin level precedes the formation of duodenal ulcers in rats treated with cysteamine.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

Herbal cardiotonic pills prevent gut ischemia/reperfusion-induced hepatic microvascular dysfunction in rats fed ethanol chronically.

AIM: Cardiotonic Pill (CP), an oral herbal medicine that includes Danshen (Salviae Miltiorrhizae), Panax notoginseny and Dyroblanops aromatica gaertn, has been clinically used for vascular diseases such as occlusive vasculitis, coronary diseases, atherosclerosis, and cerebral infarction. The main component, Salviae Miltiorrhizae, has been reported to prevent cerebral and intestinal reperfusion injury. However, little is known about the effect of CP on hepatic microcirculation. Thus, this study aimed to determine whether CP could affect hepatic microvascular dysfunction elicited by gut ischemia/reperfusion (I/R) in rats fed ethanol chronically. METHODS: Male Wistar rats were pair-fed with a liquid diet containing ethanol or isocaloric control diet for 6 wk. After laparotomy, one lobe of the liver was examined through an inverted intravital microscope. The rats were exposed to 30 min of gut ischemia followed by 60 min of reperfusion. Rhodamine-6G-labeled leukocytes in the sinusoids were observed 90 min after the onset of superior mesenteric artery occlusion. Plasma tumor necrosis factor (TNF)-alpha and endotoxin levels were measured 1 h after the onset of reperfusion. Plasma alanine aminotransferase (ALT) activities were measured 6 h after the onset of reperfusion. In another set of experiments, CP (0.8 g/kg, intragastrically) was administered 1 and 24 h before the onset of ischemia. RESULTS: In control rats, gut I/R elicited increases in the number of stationary leukocytes, and plasma TNF-alpha and endotoxin levels and plasma ALT activities. These changes were mitigated by pretreatment with CP. In ethanol-fed rats, the gut I/R-induced increases in the number of stationary leukocytes, plasma endotoxin levels and ALT activities were enhanced. Pretreatment with CP attenuated the enhancement of gut I/R-induced responses by chronic ethanol consumption. CONCLUSION: These results suggest that CP prevents the gut I/R-induced hepatic microvascular dysfunction and hepatocellular injury. A reduction of inflammatory responses such as TNF-alpha production via reduction of blood endotoxin levels appears to be involved in the mechanisms. Chronic ethanol consumption enhances gut I/R-induced hepatic microvascular and hepatocellular injury. CP also attenuates an enhancement of gut I/R-induced responses by chronic ethanol consumption via the reduction of blood endotoxin levels.

Animals↗
PubMed2005

Down-regulation of a morphogen (sonic hedgehog) gradient in the gastric epithelium of Helicobacter pylori-infected Mongolian gerbils.

Sonic hedgehog (Shh) is a morphogen involved in many aspects of patterning of the gut during embryogenesis and in gastric fundic gland homeostasis in the adult. Intestinal metaplastic change of the gastric epithelium is associated with the loss of Shh expression, and mice that lack Shh expression show intestinal transformation of the gastric mucosa. The present study was designed to investigate the alteration of Shh expression in the stomach of an experimental model of Helicobacter pylori (H. pylori) colonization. Male Mongolian gerbils were inoculated with H. pylori and examined 4 and 51 weeks later. The level of Shh mRNA expression was determined by quantitative RT-PCR and in situ hybridization. Shh protein expression was determined by immunoblotting and immunohistochemistry. Shh was expressed in the parietal cells, zymogenic cells, and mucous neck cells of the gastric fundic glands of gerbils. Prolonged colonization by H. pylori led to extension of the inflammation from the antrum to the corpus of the stomach, with loss of Shh expression. Loss of Shh expression correlated with loss of parietal cells, disturbed maturation of the mucous neck cell-zymogenic cell lineage, and increased cellular proliferation. Shh expression is significantly reduced in H. pylori-associated gastritis. These data show for the first time that H. pylori infection leads to down-regulation of the expression of a morphogen with an established role (Shh) in gastric epithelial differentiation.

Amino Acid Sequence↗
PubMed2005

Association of pseudomembranous colitis with Henoch-Schönlein purpura.

A 79-year-old man was admitted because of cholecystitis that occurred about 40 days after sigmoidectomy had been performed for colonic cancer. Though antibiotics improved his condition, the patient had hematochezia, diarrhea, and left lower abdominal pain. Colonoscopic findings showed multiple ring-like areas of redness and petechiae in the rectosigmoid colon and marked edema from the descending to the transverse colon. The patient then developed purpura on the extensor surfaces of the legs and bilateral gonalgia, and exacerbation of the hematochezia. A second colonoscopy (CS) showed multiple ring-like areas of redness and ecchymosis throughout the colon. The patient was diagnosed with Henoch-Schönlein purpura (HSP), and the symptoms were attenuated after the administration of prednisolone. However, diarrhea recurred in about a week; stool culture confirmed Clostridium difficile, and a third CS revealed pseudomembranes throughout the colon. The patient was diagnosed with pseudomembranous colitis (PMC), and the administration of vancomycin attenuated the symptoms. In conclusion, we have reported a rare adult case of PMC that occurred during prednisolone treatment for HSP. The PMC may have been caused by changes in the intestinal bacterial flora after the sigmoidectomy and by the intestinal lesions of HSP, as well as by the administration of antibiotics after the sigmoidectomy and for the treatment of cholecystitis, and by the use of prednisolone for the treatment of the HSP.

Aged↗
PubMed2005

Esophageal melanosis, an endoscopic finding associated with squamous cell neoplasms of the upper aerodigestive tract, and inactive aldehyde dehydrogenase-2 in alcoholic Japanese men.

BACKGROUND: Esophageal melanosis is often observed in alcoholic Japanese men, in whom the prevalence of squamous cell dysplasia and carcinoma (SCC) in the upper aerodigestive tract are high. This study evaluated the associations of esophageal melanosis with these neoplasms, and the factors contributing to the development of esophageal melanosis in this population. METHODS: Endoscopic screening was combined with esophageal iodine staining in 1535 alcoholic Japanese men (aged 40-79 years), of whom 1007 underwent aldehyde dehydrogenase-2 (ALDH2) genotyping. RESULTS: Fifty patients (3.3%) were diagnosed with esophageal melanosis, which had a higher incidence in those with noncancerous distinct iodine-unstained lesions (DIULs; 16/268; 6.0%), esophageal SCC (9/66; 13.6%), and oropharyngolaryngeal SCC (4/19; 21.1%) than in cancer- and DIUL-free controls (24/1182; 2.0%). The presence of esophageal melanosis was associated with higher risks for noncancerous DIULs, esophageal SCC, and oropharyngolaryngeal SCC (odds ratios, 2.81, 6.54, and 14.77, respectively). Men with the inactive ALDH2*1/2*2 genotype had a higher risk for esophageal melanosis (2.66-fold), as well as for DIULs and SCCs. CONCLUSIONS: The presence of esophageal melanosis in alcoholic Japanese men could indicate a high risk for DIULs and SCCs in the upper aerodigestive tract. The high incidence of esophageal melanosis may be partially linked to high acetaldehyde exposure, a consequence of drinking alcohol in persons with inactive ALDH2.

Adult↗
PubMed2005

A novel apoptosis-inducing monoclonal antibody (anti-LHK) against a cell surface antigen on colon cancer cells.

BACKGROUND: Apoptosis is a crucial element in the behavior of mammalian cells in many different situations. We here report the establishment of a novel monoclonal antibody (anti-LHK mAb) that has apoptosis-inducing activity against colon cancer Colo205 cells. METHODS: The mechanism of anti-LHK mAb-induced cell death was assessed by microscopic morphology, Annexin V/Hoechst 33528 staining, and detection of DNA fragmentation. The molecular weight of LHK antigen was determined by Western blotting. Growth inhibition of Colo205 cells induced by anti-LHK mAb was determined by in vitro and in vivo studies. RESULTS: Anti-LHK reacted with a 70-kDa antigen and completely blocked the proliferation of Colo205 cells bearing LHK in vitro in a manner characteristic of apoptosis. Strikingly, anti-LHK mAb suppressed tumor growth in a murine peritoneal dissemination model. CONCLUSIONS: LHK antigen, which is restricted to epithelial cells, may be a novel death receptor that plays a critical role in controlling the growth, invasion, and metastasis of human colon cancer cells.

Animals↗
PubMed2005

Identification and characterization of novel gut-associated lymphoid tissues in rat small intestine.

BACKGROUND: The crypt lamina propria of the mouse small intestine has been shown to harbor multiple tiny clusters filled with c-kit- and interleukin 7 receptor (IL-7R)-positive lympho-hemopoietic cells (cryptopatches; CPs). However, it has remained an open question whether similar lymphoid tissue are present in the gastrointesitinal tract in other animals. In the present study, we investigated whether the small intestine of rats harbored lymphoid tissues similar to mouse CPs. METHODS: Immunohistochemical and flow cytometric analyses were carried out using various antibodies, including those to c-kit and IL-7R molecules. RESULTS: Lymphocyte-filled villi (LFVs), populated predominantly with c-kit- and IL-7 receptor (IL-7R)-positive cells and less with T cell receptor (TCR)-alphabeta T cells were found throughout the small intestine of young adult rats. Although LFVs were absent from fetal rat intestine, they were first detected at around 2 weeks after birth. Notably, in most LFVs that settled in the antimesenteric wall of the small intestine in young adult rats, immunoglobulin M-positive B cells were also detectable at the bottom of the LFVs. In aged rats, lymphocytes in some LFVs displayed a different phenotype, comprising a large B-cell area that included a germinal center. Thus, these clusters represent the first description of isolated lymphoid follicles (ILFs) in the rat small intestine. CONCLUSIONS: The present study provides the first evidence for c-kit- and IL-7R-positive lymphocyte clusters in the rat small intestine. Our data also indicating that LFVs and ILFs may constitute novel organized gut-associated lymphoid tissues in lamina propria of the rat small intestine.

Animals↗
PubMed2005

Contribution of Irf-1 promoter polymorphisms to the Th1-type cell response and interferon-beta monotherapy for chronic hepatitis C.

We recently reported promoter polymorphisms in the IRF-1 gene, an interferon-inducible gene that plays an important role in host antiviral function. The promoter activity was shown to be different between different polymorphisms. In this study, we investigated the relationship between IRF-1 promoter polymorphisms and the response to interferon monotherapy for chronic hepatitis C. Eighteen patients with a low initial viral load or hepatitis C virus (HCV) genotype non-1b received 6-months course of interferon-beta monotherapy. IRF-1 gene mutations and the treatment response were investigated. The IRF-1 promoter type possessing a higher promoter activity (-415C/-410A/-300A) was found in only three patients, all of which had a lower viral load than those with other promoter types and were able to obtain a sustained viral response. Flow cytometric analysis of peripheral blood mononuclear cells showed that the patients with a higher promoter activity of the IRF-1 had a significantly higher proportion of T helper 1-type CD4(+) cells after interferon administration than those of other promoter types. These results suggest that IRF-1 promoter polymorphisms may contribute, at least partially, to host antiviral activity for chronic hepatitis C.

Journal Article↗
PubMed2005

Increase of bone marrow-derived secretory lineage epithelial cells during regeneration in the human intestine.

BACKGROUND & AIMS: We have previously reported that bone marrow (BM)-derived cells contribute to the regeneration of the human intestinal epithelium. To analyze further how these cells arise, proliferate, and differentiate as epithelial cells, histologic analysis was conducted using endoscopic specimens. METHODS: Thirty biopsy specimens from 14 female, sex-mismatched BM-transplantation recipients were examined. BM-derived cells were identified by fluorescent in situ hybridization (FISH) for the Y chromosome and immunohistochemistry. Multicolor FISH was used to exclude cell fusion. These cells were further analyzed for various differentiation or proliferation markers. RESULTS: No evidence of cell fusion was detected. BM-derived cells did not distribute within the crypt as stem cells and rarely expressed Musashi-1. However, BM-derived epithelial cells frequently expressed Ki-67, and some of these cells appeared as pairs of adjacent cells. These cells also expressed markers of all 4 lineages of terminally differentiated cells. During regeneration following graft-vs-host disease, the number of BM-derived cells was substantially increased within Ki-67-positive cells. Interestingly, the number of cells expressing markers for secretory lineage cells was significantly increased within BM-derived cells. This change was unique for BM-derived cells, resulting in a significantly increased proportion of BM-derived cells among secretory lineage cells. CONCLUSIONS: BM-derived epithelial cells arise via a mechanism other than cell fusion and rarely give rise to stem cells. However, a small proportion of these cells express proliferation markers, and a majority reside as terminally differentiated cells. During regeneration BM-derived cells increase as secretory lineage cells, thereby contributing to restore epithelial functions.

Biopsy↗
PubMed2005

Therapeutic efficacy of infliximab on active Crohn's disease under nutritional therapy.

OBJECTIVE: The aim of this investigation was to elucidate retrospectively the therapeutic effect of infliximab in patients with active Crohn's disease (CD) under nutritional therapy. MATERIAL AND METHODS: Using a review of the clinical records in 24 nationwide institutions specializing in inflammatory bowel disease, the short-term effect of infliximab in 97 patients with active CD was retrospectively investigated. The Crohn's disease activity index (CDAI) at baseline and after 2 weeks of a single infliximab administration (5 mg/kg) was compared among patients under total parenteral nutrition (TPN group, n=36), those following an elemental or polymeric diet (EN group, n=49) and those without TPN and EN (NN group, n=12). A decrease in CDAI >or= 70 or a CDAI value <150 at 2 weeks was regarded as effective. RESULTS: There was no difference in CDAI at baseline among the three groups. In each group, CDAI decreased significantly (from 250 (195-290) [median (interquartiles)] to 152 (123-233) in the TPN group, p<0.0001; from 259 (200-325) to 180 (130-238) in the EN group, p<0.0001; from 278 (222-291) to 164 (132-196) in the NN group, p=0.003). Infliximab was effective in 63.9% of patients in the TPN group, in 55.1% of those in the EN group and in 75% of the NN group. There was no statistical difference in efficacy among the three groups (p=0.4). Multivariate logistic regression analysis revealed younger age to be a significant factor related to the efficacy of infliximab. CONCLUSIONS: Infliximab is effective in patients with CD under TPN or EN. Age at infliximab administration may be predictive of response to infliximab.

Adolescent↗
PubMed2005

AICAR, an AMPK activator, has protective effects on alcohol-induced fatty liver in rats.

BACKGROUND: Previous work with metformin has shown that this antidiabetic agent improves nonalcoholic fatty liver in ob/ob mice. AMP-activated protein kinase (AMPK) is one of the major cellular regulators of lipid and glucose metabolism, and reportedly mediates the beneficial metabolic effects of metformin. In this study, we examined the effects of 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR), an AMPK activator, on an experimental model of ethanol-induced hepatic steatosis. METHODS: Rats were randomly divided into three groups: (A) rats fed ethanol-containing liquid diet for six weeks; (B) rats pair-fed ethanol-containing liquid diet for six weeks, during the last three weeks of which they were subcutaneously injected with 0.5 mg AICAR/g body weight per day; (C) rats pair-fed isocaloric liquid diet without ethanol for six weeks. At the end of the six-week period, the animals were sacrificed. Serum and liver specimens were analyzed using biochemical and histologic methods, as well as real-time PCR. RESULTS: Chronic ethanol feeding resulted in fatty liver both histologically and biochemically, whereas AICAR administration attenuated the degree of change in the liver. AICAR also decreased the hepatic sterol regulatory factor binding protein-1c (SREBP-1c) and reduced fatty acid synthase (FAS) expression; these changes led to reduced triglyceride synthesis in rat livers. Furthermore, detection of 4-hydroxy-2-nonenal (4-HNE)-protein adducts showed that the AICAR treatment also decreased the products of lipid peroxidation. CONCLUSION: In this preclinical rat model, AICAR, an AMPK activator, appears to protect the liver from fatty changes associated with chronic alcohol use. As such, AICAR may have a role in the treatment and prevention of alcohol-induced fatty liver.

AMP-Activated Protein Kinases↗
PubMed2005

Severe alcoholic hepatitis in Japan: prognosis and therapy.

BACKGROUND: Recently, the incidence of alcoholic liver disease (ALD) has been increasing in Japan; this associated with an increase in alcoholic beverage consumption. Multiple organ failures are frequently observed in patients with severe alcoholic hepatitis (AH), most of whom have a poor prognosis similar to fulminant hepatitis; as well numbers of severe AH patients appear to be increasing. Although prognosis of fulminant hepatitis in Japan has been recently improved by intensive treatments such as plasma exchange (PE) that of severe AH has not changed. The objective of this study was to determine whether there was any factor that could determine the prognosis of severe AH. METHODS: We carried out nation-wide survey by asking hospitals certified by the Japanese Society of Gastroenterology and hospitals related to ours hospital for the current status of patients seen with severe alcoholic hepatitis since 1998. We investigated correlations between various factors including blood laboratory data, presence of other organ failure, and prognosis. RESULTS: Mortality of patients with severe AH was high (66.4%). The ratio of female patients with severe AH (26%) was higher than that for other ALD (approximately 10%). Mean age was older (Alive: 44 +/- 11; Dead: 50 +/- 11 years old), white blood cell (WBC) counts were higher (11600 +/- 5200; 21800 +/- 13400/microl), red blood cell counts were lower (320 +/- 95; 265 +/- 72 x 10/microl) and prothrombin time (PT) was prolonged (36.2 +/- 10.4; 29.1 +/- 9.4%, respectively) in patients who had died than in patients who had survived. However, as all differences diminished after carrying out PE, we analyzed data in patients without PE. The results were similar to those in all patients. Prevalence of infection, gastrointestinal (GI) bleeding and disseminated intravascular coagulation (DIC) was higher in patients who had died. Although intensive treatments such as PE, hemodialysis, and anticoagulation therapy did not change the prognosis of severe AH, PE improved the prognosis of patients without either GI bleeding or DIC. WBC counts were also slightly higher in patients who had died after carrying out PE. Two cases had been cured by granulocytapheresis (GCAP) CONCLUSIONS: PE can compensate for and reduce the risk due to prolonged PT in patients with severe AH. These results suggest that the patients with markedly elevated WBC counts, prolonged PT, or anemia should, if possible, be treated at an earlier stage with an intensive treatment such as PE, hemodialysis, or anticoagulation therapy before infection, GI bleeding or DIC occurs. Further, GCAP might be useful for severe AH patients with higher WBC counts.

Adult↗
PubMed2005

Nonpathogenic Escherichia coli strain Nissle1917 prevents murine acute and chronic colitis.

BACKGROUND: Nonpathogenic Escherichia coli strain Nissle1917 has been used as a probiotics in human inflammatory bowel disease; however, there are few reports examining its therapeutic effect on animal colitis models, and its therapeutic mechanisms remain unknown. The aim of this study was to elucidate the therapeutic effect and mechanism of Nissle1917 using murine acute and chronic colitis models. METHODS: Two models were used. (1) Acute model: colitis was induced by administration of 1.3% dextran sodium sulfate for 7 days. Nissle1917 or phosphate-buffered saline were orally administered for 10 days. Mice were killed at day 10, and the colonic lesions were assessed macro- and microscopically. (2) Chronic model: IL-10 mice were treated with Nissle1917 or phosphate-buffered saline for 8 weeks. After 8 weeks of treatment, mice were killed to assess the colonic lesions macro- and microscopically. In the acute dextran sodium sulfate colitis model, viable, heat-killed, or genomic DNA of Nissle1917 was orally administered for 10 days, and the therapeutic effect was assessed. RESULTS: In the acute model, Nissle1917 ameliorated body weight loss, disease activity index, and macro- and microscopic damage. In the chronic model, it also suppressed the mucosal inflammatory findings and histologic damages. Moreover, heat-killed Nissle1917 or its genomic DNA alone also ameliorated the acute DSS colitis and viable bacteria macro- and microscopically. CONCLUSIONS: Nonpathogenic E. coli strain Nissle1917 prevents both acute and chronic colitis, and its anti-inflammatory effect is exhibited not only by viable bacteria but also by heat-killed bacteria or its DNA.

Acute Disease↗
PubMed2005

Clinical significance of microsatellite instability in the inflamed mucosa for the prediction of colonic neoplasms in patients with ulcerative colitis.

BACKGROUND AND AIM: Although molecular mechanisms underlying ulcerative colitis (UC)-associated neoplasms have been studied for years, understanding of these mechanisms remains incomplete and no good predictable marker for development of colonic neoplasms in patients with UC has been established. The aim of this study was to assess if microsatellite instability (MSI) contributes to the development of colonic neoplasms in patients with UC. METHODS: We have examined MSI in chronic inflamed and neoplastic colonic mucosa of UC patients. We have also obtained serial biopsied colonic tissues retrospectively 2-12 years before the final diagnosis from patients with high level MSI (MSI-H+) UC-associated neoplasms, and analyzed MSI using them at different periods. RESULTS: Eight of 12 UC-associated colon cancers (67%), four of six UC-associated high grade dysplasias (67%), and two of six UC-associated low grade dysplasias (33%) revealed MSI-H+ phenotypes. In contrast, 15 of 59 lesions (25%) in inflamed UC mucosa without colonic neoplasm revealed MSI-H +. Interestingly, all four patients with MSI-H+ phenotypes at the final diagnosis of UC-associated colon cancer or dysplasia had already had MSI-H+ at the stage of chronic colitis, 2-12 years before the final diagnosis. CONCLUSION: These results support the notion that MSI contributes to the carcinogenesis of UC-associated neoplasms, and indicate that this analysis in inflamed colonic mucosa at surveillance colonoscopy is useful for identifying UC patients who have high risk for neoplastic progression.

Adenocarcinoma↗