Rectal cell proliferation and colorectal cancer risk level in patients with nonfamilial adenomatous polyps of the large bowel.

The authors evaluated cell kinetics of apparently normal rectal mucosa in the following subjects: 25 with single small adenoma (smaller than 10 mm) of the large bowel, 12 with multiple small adenomas, 28 with a single large adenoma (larger than 10 mm), 22 bearing multiple adenomas among which at least one was larger than 10 mm, 32 with cancer of the large intestine, and 32 controls without colorectal diseases. The study was performed by means of incubation of biopsy specimens with tritiated thymidine and autoradiography. The labeling index was similar in all of the groups. However, patients with one or more large adenomas showed a shift of the proliferative compartment toward the top of the crypts similar to that observed in patients with cancer. This abnormal proliferative pattern was not noticed in patients with one or more small adenomas and was not related to the number of adenomas of each subject. The presence of defects of cell growth in the normal rectal mucosa of patients with large adenomas may indicate that subjects with this abnormality are at high risk of adenoma growth and progression to cancer.

Antibodies to Campylobacter pylori in patients with idiopathic dyspepsia.

We used Western Blotting analysis to determine the immune profile to Campylobacter pylori polypeptides in: A) sera from patients with idiopathic dyspepsia and bacteriological evidence of C. pylori gastric colonization, B) sera from patients with the same symptoms but no bacteriological evidence of C. pylori infection and C) healthy subjects. To avoid interference of aspecific reactions due to antigenic cross reactivity with other thermophilic Campylobacter species, antisera were raised in rabbits against C. pylori as well as against C. coli and C. jejuni. Some bands (with an approximate molecular weight of 118, 85, 40, 34, 28, 18 and 12 Kd) which can be considered specific for C. pylori were identified and the IgG reaction to some of them (40, 34, 28 Kd) was shown to be significantly higher in patients with bacteriological evidence of C. pylori infection than in the other two groups. IgM reactivity to two bacterial proteins of molecular weight 118 and 40 Kd was particularly evident in the second group of patients suggesting a possible diagnostic tool to identify C. pylori infection at a very early stage.

Cell renewal and cancer risk of the stomach: analysis of cell proliferation kinetics in atrophic gastritis.

We examined cell proliferation kinetics of gastric mucosa in 28 patients affected by chronic atrophic gastritis by means of autohistoradiography of biopsies incubated with tritiated thymidine. The results have been compared with those obtained from 12 patients with normal gastric mucosa. In chronic atrophic gastritis, patients showed a proliferative pattern similar to controls. The remaining patients had an increased number of replicating cells together with an expansion of the proliferative compartment towards the surface of the mucosa. These results suggest that in chronic atrophic gastritis, as far as cell proliferation is concerned, two subgroups of patients with two different levels of risk of developing gastric cancer exist. The first one, showing an expansion of the proliferating area, probably is at higher risk. As a matter of fact, such an abnormality expresses an alteration of cell growth control similar to that observed in preneoplastic conditions of the colon and in gastric mucosa of animals treated with carcinogenic substances.