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M Risio

Publications and source records attributed to M Risio.

56 records · Page 4Linked to original sources
PubMedDate not supplied

Cell proliferation in colorectal adenomas containing invasive carcinoma.

Immunohistochemical detection of the nuclear antigen recognised by the monoclonal antibody Ki67, DNA polymerase alpha, and the proliferating cell nuclear antigen (PCNA), and histochemical staining for the argyrophilic proteins associated with the nucleolar organizer regions (AgNOR) were carried out on histological sections from 107 colorectal adenomas containing invasive carcinoma (ACIC), including 7 with regional lymph node metastases. Separate evaluations were made for fields corresponding to adenoma with low-grade dysplasia, adenoma with high-grade dysplasia and early cancer. The same techniques were also employed in 20 cases of normal mucosa and 20 advanced carcinomas. The mean percentages of Ki67, DNA polymerase alpha, and PCNA-positive nuclei and the number of AgNOR per nucleus progressively increased along the sequence from normal mucosa via low-grade and high-grade dysplasia adenoma to advanced cancer, whereas the early cancer values were not significantly different from those in the low-grade dysplasia areas. No significant difference in PCNA positivity and number of AgNOR were noted in ACIC with and without lymph node metastases. It is suggested that the decrease in proliferative activity thus revealed in early cancer may be due to changes in the submucosa microenvironment caused by invasion, and that the metastatic potential of an early colorectal cancer cannot be correlated to such activity.

Adenoma↗
PubMedDate not supplied

Bromodeoxyuridine uptake and proliferating cell nuclear antigen expression throughout the colorectal tumor sequence.

In vitro uptake of bromodeoxyuridine and expression of proliferating cell nuclear antigen (PCNA) were evaluated histochemically in rectal mucosa of control subjects and subjects with colorectal neoplasia in large intestine adenomas and adenocarcinomas. Both labeling indices progressively increased along the path of tumor progression, as did the difference between them (PCNA labeling indices were always greater than those of bromodeoxyuridine). The correlation between them was fairly close in the controls and in adenomas with low-grade dysplasia, whereas no significant linear relations were noted in adenomas with high-grade dysplasia or in adenocarcinomas. The progressive increase in PCNA would thus seem to be related to both hyperproliferation and neoplastic deregulation of PCNA synthesis. In the mucosa of subjects with colorectal neoplasia, PCNA labeling revealed hyperproliferation but not the surface-wards shift of the proliferative compartment detected by bromodeoxyuridine. PCNA expression, therefore, is not a sufficiently sensitive marker of the risk of tumor transformation in the intestinal mucosa.

Adenocarcinoma↗