Cell proliferation, nuclear ploidy, and EGFr and HER2/neu tyrosine kinase oncoproteins in infiltrating ductal breast carcinoma.

The purpose of this work was to study if the variations in the nuclear DNA content and the expression of EGFr and HER2/neu transmembrane oncoproteins were related and if this influences the rate of cell proliferation modifying, in each case, the potential aggressivity of the neoplasia. Thirty-four ductal breast carcinoma tissue samples of tumors of up to 2 cm in diameter were analyzed by flow cytometry. HER2/neu and EGFr were measured by immunohistochemical methods. Twenty cases were diploid (DNA index of 1) and 14 cases were aneuploid (DNA index other than 1). The expression of EGFr and HER2/neu was significantly higher in aneuploid tumors compared with diploid tumors. The cell proliferation rate was significantly higher in tumors with an aneuploid pattern. The expression of EGFr was associated with a higher rate of cell proliferation. The higher expression of EGFr and HER 2/neu oncoproteins in aneuploid tumors suggests that the increased proliferative activity of aneuploid carcinomas is influenced by the activity of such oncoproteins, which favors a more aggressive biological behavior.

Rat neonatal intestinal wall-free graft.

An experimental study was carried out in order to evaluate the regeneration capacity of the neonatal intestinal wall in ischaemia and its repercussion over organs of the immune system such as the spleen. We isolated a reservoir of small intestine in adult Sprague-Dawley rats that, after having been everted and placed at a subcutaneous level, was grafted with a free small intestine segment of neonatal Sprague-Dawley rats and analysed 3, 15 and 30 days after grafting. Samples obtained were stained with Martin's trichromic stain and studied at the light microscopic level. A total regeneration of the crypt architecture, formed by absorptive enterocytes, was observed in the interior of the reservoirs. A quantitative immunohistochemical study with monoclonal antibodies against CD4, CD8, MHC I and MHC II was carried out in the spleen of these animals. An additional immunohistochemical study was also performed in the small intestine reservoirs and spleen of transplanted animals using nitric oxide synthase (NOS) antibodies. Three days after transplantation NOS immunoreactive cells were observed in the reservoirs with transplanted neonatal small intestine. Antigenic stimulation produced, in the spleen red pulp of transplanted animals, a significant increase (P < 0.001) in the percentage of NOS, CD8 and MHC I immunoreactive cells in relation with values observed in control animals. These morphometric changes could be related with the stimulation that nitric oxide produces in the proliferation of the cytotoxic T cells.

DNA ploidy and PCNA index in pancreatic lesions producing hyperinsulinemic hypoglycemia.

DNA nuclear content and PCNA index (proportion of PCNA reactive cells) have been studied by flow cytometry in eight pancreatic lesions producing hyperinsulinemic hypoglycemia to assess DNA ploidy and tumoral growth fraction. Adult nesidioblastosis had a diploid DNA index, two adenomas were near diploid, and four of the adenomas and the carcinoma were aneuploid. The median value of PCNA index (6.056% +/- 6.76) was significantly correlated (P < 0.05) with the mean tumor diameter (2.43 cm +/- 1.96). Tumors with a PCNA index < 6.056% showed a diameter less than the mean tumoral diameter and a benign clinical course. Tumors with PCNA index > 6.056% generally displayed a diameter bigger than the mean tumoral diameter, being associated with lymph node metastases in one case. The authors conclude that nuclear DNA and PCNA index cytometric studies are useful parameters to assess the biological behavior of pancreatic lesions producing hyperinsulinemic hypoglycemia.