Metaplasia, intestinal

Incidence of Stomach Epithelium Hyperplasia and Intestinal Metaplasia (66)... 

Group and Treatment Number of Rats Squamous Cell Hyperplasia Glandular Hyperplasia Intestinal Metaplasia... 

One rat had only forestomach hyperplasia 3 also had glandular hyperplasia 1 had intestinal metaplasia. 

One rat had only intestinal metaplasia 1 also had only forestomach hyperplasia 2 also had only glandular hyperplasia 2 had all three lesions. 

Alterations in other gastric secretions, such as pepsinogens and blood group substances also take place in chronic atrophic gastritis. The secretion of pepsinogen I has been used as an indicator of intestinal metaplasia and gastric cancer (21, 22). 

The process, once initiated, is self-sustaining and may become more accelerated with time because the atrophy and intestinal metaplasia are progressive lesions and lead to further loss of parietal cells and incrased bacterial colonization of the mucosa. The initial mutations transform gastric cells into mature intestinal-type cells. Further superimposed mutations transform metaplastic cells into progressively dysplastic cells and eventually into neoplastic cells. This is a process of loss of differentiation which implies a multihit phenomenon which could be explained on the basis of continued formation of minute amounts of nitroso compounds over many years. 

Prolonged hypergastrinemia leading to the development of colonic polyps and potentially adenocarcinoma in rats was a concern that has proven to be unfounded with long-term use in humans.19 The FDA has stated that there is insufficient evidence linking PPI use to atrophic gastritis, intestinal metaplasia, or gastric cancer.20... 

Hirayama F, Takagi S, Kusuhara H, Iwao E, Yokoyama Y, Ikeda Y. (1996) Induction of gastric ulcer and intestinal metaplasia in Mongolian gerbils infected with Helicobacter pylori. J Gastroenterol 31 755-757. 

Patients with healed GERD were treated for up to 40 months with rabeprazole and monitored with serial gastric biopsies. Approximately 4% of patients had intestinal metaplasia at some point during follow-up, but no consistent changes were seen. Hepatic effects In patients with various degrees/types of hepatic disease, the AUC was prolonged (lansoprazole, esomeprazole, rabeprazole, pantoprazole), half-life was prolonged (lansoprazole, omeprazole, rabeprazole, pantoprazole), increased bioavailability was observed (omeprazole), decreased clearance with rabeprazole and increased maximum pantoprazole concentrations. 

Type I tumor Adenocarcinoma of the distal esophagus, which usually arises from an area with specialized intestinal metaplasia of the esophagus (i.e., Barrett s esophagus) and which may infiltrate the esophagogastric junction from above. 

Type II tumor True carcinoma of the cardia arising from the cardiac epithelium or short segments with intestinal metaplasia at the esophagogastric junction. 

Sugimura T, Matsukura N, Sato S. Intestinal metaplasia of the stomach as a precancerous stage. IARCSciPubl 1982 39 515-530. 

Among patients infected with H pylori, long-term acid suppression leads to increased chronic inflammation in the gastric body and decreased inflammation in the antrum. Concerns have been raised that increased gastric inflammation may accelerate gastric gland atrophy (atrophic gastritis) and intestinal metaplasia—known risk factors for... 

In a phase I clinical trial patients with recently resected urinary bladder cancer, uterine cervical intraepithelial neoplasm (CIN), oral leucoplakia, and intestinal metaplasia of the stomach were enrolled and treated with 0.5-12 g/... 

Table 13.1. Details of spectra included in the biopsy targeting model. Each of the pathology groups is made up of a combination of others (e.g. Barrett s includes samples of fundic, cardiac and intestinal metaplasia)...

Of 33 patients with severe reflux esophagitis prospectively followed up for 5-8 years six were positive for H. pylori (16). There was no evidence of significant enterochromaffin-hke cell hyperplasia, gastric atrophy, intestinal metaplasia, dysplasia, or neoplastic changes during 185 patient foUow-up years during which 137 gastric biopsies were taken. 

There has been concern about the potential for proton pump inhibitors to cause enterochromaffin-hke cell hyperplasia, gastric carcinoid tumors and gastric cancers, colorectal polyps and adenocarcinoma, atrophic gastritis, and intestinal metaplasia in patients with H. pylori infection, and bacterial overgrowth. 

There is very limited evidence for CYP expression in the human stomach. Furthermore, it is difficult to propose any function for gastric CYPs because the gastric epithelium secretes rather than absorbs. However, the potential of those CYPs expressed in the stomach to play roles in stomach cancer has been investigated in cases of intestinal metaplasia of the stomach. Intestinal metaplasia of the stomach, which involves the replacement of the gastric mucosa with a small intestine-like epithelium (100), is considered to be a precancerous lesion (101). A combination... 

Similar results were obtained with immunoblot and RT-PCR probes for CYP1A1 and 1A2 (103). CYP1A1 and 1A2, as well as CPR, were reported to be detected in human gastric mucosa with intestinal metaplasia and in pyloric gland cells. Mi-crosomes prepared from these cells activated BaP and 2-amino-2-methy limidazole [4,5-f]quinoline. 

In view of the precancerous nature of intestinal metaplasia, it has been postulated that the coincident expression of various CYPs in the gastric mucosa of such patients plays a role in the bioactivation of gastric carcinogens. In a comparison of normal stomach tissue with stomach cancer, it was determined that in the normal tissue, no CYPs were detected, whereas in the case of stomach cancer, CYP1A and 3 A were detected in 51% and 28% of cases, respectively (104). The presence of intestinal metaplasia was not noted in this study. 

Stemmermann GN. 1994. Intestinal metaplasia of the stomach a status report. Cancer 74 556-64... 

Hirota T, Okada T, Itabashi M, Yoshida H, Matsujura H, et al. 1984. Significance of intestinal metaplasia as a precancerous condition of the stomach. In Precursors of Gastric Cancer, ed. SC Ming, pp. 179-93. New York Praeger... 

Yokose T, Doy M, Kakiki M, Horie T, Matsuzaki Y, Mukai K. 1998. Expression of cytochrome P450 3A4 in foveolar epithelium with intestinal metaplasia of the human stomach. Jpn. J. Cancer Res. 89 1028-32... 

Tatemichi M, Nomura S, Ogura T, Sone H, Nagata H, Esumi H. 1999. Mutagenic activation of environmental carcinogens by microsomes of gastric mucosa with intestinal metaplasia. Cancer Res. 59 3893-98... 

S., Cho, K.R. and Fearon, E.R. (2002) CDX2 regulates liver intestine-cadherin expression in normal and malignant colon epithelium and intestinal metaplasia. Gastroenterology, 123 (5), 1565-1577. 

CDX2 co-localizes with liver—intestine cadherin in intestinal metaplasia and adenocarcinoma of the stomach. The Journal of Pathology, 205 (5), 615-622. 

Cameron AJ, Kamalh PS, Carpenter HA. Prevalence of Barrett esophagus and intestinal metaplasia at the esophagogastric junction. Gastroenterology 1997 112 A82. 

Morgan RW, Ward JM, Hartman PE. 1981. Aroclor 1254-induced intestinal metaplasia and adenocarcinoma in the glandular stomach of F344 rats. Cancer Res 41 5052-5059. 

Bai YQ, Yamamoto H, Akiyama Y, et al. Ectopic expression of homeodomain protein CDX2 in intestinal metaplasia and carcinomas of the stomach. Cancer Lett. 2002 176 47-55. 

Barrett esophagus (BE) is defined as intestinal metaplasia in association with endoscopically recognized columnar metaplasia of the gastroesophageal junction. This... 

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