Expression of Cdx2 and claudin-2 in the multistage tissue of gastric carcinogenesis.

In this paper, we investigated Cdx2 and claudin-2 expression in pathological paraffin tissues of sinus ventriculi from gastroscopic biopsy to determine the correlation between the expressions of these 2 genes during gastric carcinogenesis by immunochemical ABC technique. Altogether, we analyzed 108 chronic superficial gastritis, 55 chronic atrophic gastritis, 109 intestinal-type metaplasia, 93 dysplasia and 52 gastric intestinal-type adenocarcinoma samples. Our results indicated that the percentage of Cdx2-positive cases was 0% (0/108) for chronic superficial gastritis, 0% (0/55) for chronic atrophic gastritis, 90.83% (99/109) for intestinal-type metaplasia, 51.61% (48/93) for dysplasia and 61.54% (32/52) for gastric intestinal-type adenocarcinoma, primarily expressed in the cell nucleus and partly in the cytoplasm (p < 0.05); interestingly, the percentage for the intestine-type metaplasia was markedly high. The percentage of claudin-2-positive cases was 0% (0/108) for chronic superficial gastritis, 0% (0/55) for chronic atrophic gastritis, 0% (0/109) for intestinal-type metaplasia, 35.48% (33/93) for dysplasia and 71.15% (37/52) for gastric intestinal-type adenocarcinoma, primarily in the cell membrane and gradually increased in the multistage process of gastric carcinogenesis (p < 0.05). Significant correlations were found between claudin-2 and Cdx2 protein expression in dysplasia and intestine-type adenocarcinoma (r = 0.112, p < 0.05). Thus, there may be a correlation between the expression of claudin-2 and Cdx2 in stages of dysplasia and cancer.

Liver fluke-associated and sporadic cholangiocarcinoma: an immunohistochemical study of bile duct, peribiliary gland and tumour cell phenotypes.

AIM: To compare cell phenotypes displayed by cholangiocarcinomas and adjacent bile duct lesions in patients from an area endemic in liver-fluke infestation and those with sporadic cholangiocarcinoma. METHODS: 65 fluke-associated and 47 sporadic cholangiocarcinomas and 6 normal livers were studied. Serial paraffin-wax sections were stained immunohistochemically with monoclonal antibodies characterising a Brunner or pyloric gland metaplasia cell phenotype (antigens D10 and 1F6), intestinal goblet cells (antigen 17NM), gastric foveolar apomucin (MUC5AC), a gastrointestinal epithelium cytokeratin (CK20) and the p53 protein. RESULTS: 60% of the 112 cholangiocarcinomas expressed antigen D10, 68% MUC5AC, 33% antigen 17NM and 20% CK20; 37% showed overexpression of p53. When present together in a cholangiocarcinoma, cancer cells expressing D10 were distinct from those displaying 17NM or MUC5AC. Many more fluke-associated cholangiocarcinomas than sporadic cholangiocarcinomas displayed 17NM and p53 expression. Most cases of hyperplastic and dysplastic biliary epithelium expressed D10 strongly. Pyloric gland metaplasia and peribiliary glands displayed D10 and 1F6, with peribiliary gland hyperplasia more evident in the livers with fluke-associated cholangiocarcinoma; goblet cells in intestinal metaplasia stained for 17NM. No notable association of expression between any two antigens (including p53) was found in the cancers. CONCLUSIONS: Most cases of dysplastic biliary epithelium and cholangiocarcinoma display a Brunner or pyloric gland cell phenotype and a gastric foveolar cell phenotype. The expression of D10 in hyperplastic and dysplastic epithelium and in cholangiocarcinoma is consistent with a dysplasia-carcinoma sequence. Many more fluke-associated cholangiocarcinomas than sporadic cholangiocarcinoma display an intestinal goblet cell phenotype and overexpress p53, indicating differences in the aetiopathology of the cancers in the two groups of patients.

Gastric giardiasis.

AIMS: To assess the prevalence of gastric giardiasis in patients undergoing upper gastrointestinal endoscopy, and to define the clinicopathological correlates of gastric Giardia lamblia infection. METHODS: Consecutive gastric biopsy specimens (n = 15,023) from 11,085 patients, taken at Feltre City Hospital (north eastern Italy) from January 1986 to December 1991, were histologically and immunocytochemically examined for the occurrence of G lamblia trophozoites. Three gastric biopsy specimens from patients harbouring G lamblia infection, who repeated endoscopy before treatment, were also examined electron microscopically. RESULTS: Forty one patients (0.37% of the population study) harboured gastric giardiasis. All patients underwent upper gastrointestinal endoscopy because of dyspepsia, epigastric pain, or abdominal distension. Only two patients had diarrhoea at the time of investigation. Giardiasis was clinically unsuspected in all cases, although the nine patients who also had duodenal biopsies performed had concomitant intestinal giardiasis. Gastric giardiasis was invariably associated with chronic atrophic gastritis. Intestinal metaplasia of the gastric mucosa and Helicobacter pylori infection were found in 32 and 37 of the 41 patients with gastric giardiasis, respectively. CONCLUSIONS: The invariable association of gastric giardiasis with chronic atrophic gastritis, most often showing intestinal metaplasia and H pylori infection, indicates that a decreased gastric acidity is a prerequisite for localisation of G lamblia to the gastric mucosa. Though its possible role as a gastric pathogen remains to be elucidated, these findings suggest that trophozoites should be carefully searched for when examining gastric biopsy specimens showing chronic atrophic gastritis.