PNA: A Marker of Neoplastic Progression and Differentiation in the Gastrointestinal Tract

We examined 35 cases of stomach carcinoma and 40 cases of colonic carcinoma with PNA associated with peroxidase (peanut agglutinin, lectin which binds to the terminal disaccharide galactose β (1, 3)-N-acetil-galacto-samine).

In this way evaluation of the functional aspects of the normal-neoplastic sequence was undertaken. This method was carried out for histological and ultrastructural investigations. The results obtained in both cases showed a different reactivity in the evolution of neoplastic disease: in fact, positivity in dysplasia is finely granular intracytoplasmic, whereas in well-differentiated neoplastic transformation such a reactivity is preferentially localized along the cellular membranes, with restoration of gross positivity in the cytoplasm for the poorly-differentiated neoplasm. We therefore believe PNA to be a marker not only of neoplastic progression but of differentiation as well: we also hypothesize it to reveal glycoprotein groups with possible antigenic power, involved in immunologic interactions between tumor and host.

Growth Fraction of Colorectal Carcinoma (Ki67): A Comparative Study

We studied the growth fraction of55 resected colorectal adenocarcinomas by means of a three-step immunoperoxidase technique (avidin-biotin-peroxidase) using the monoclonal antibody Ki67 directed against a cell proliferation-associated nuclear antigen.

The percentage of Ki67-positive cells was evaluated independently by two observers, and a Ki67 score was obtained for each case.

No correlation was observed between Ki67 staining and patient's age and sex, tumor size and localization or grading and staging according to Dukes’ method (modified by Astler-Coller and Turnbull).

The growth fraction showed extreme heterogeneity in the cases examined, within each grade of differentiation.

Chromosome 9 instability and alterations of p16 gene in squamous cell carcinoma of the lung and in adjacent normal bronchi: FISH and immunohistochemical study

AIMS

p16, a tumour suppressor gene located at 9p21 chromosome and involved in cell cycle regulation, is often inactivated in lung carcinoma. Inactivation is also supported by the loss of p16 protein, a strong inhibitor of cyclin-dependent kinase (CDK) 4 and 6. The aim of this study was to examine alterations of p16 both in pulmonary squamous cell carcinoma (SCC) and in morphological normal bronchi contiguous with neoplasia.

METHODS AND RESULTS

p16 gene and chromosome 9 alterations were examined by fluorescence in situ hybridization and the expression of p16 protein by immunohistochemistry in pulmonary surgical specimens from 31 patients with SCC. As controls, surgical specimens from 13 patients with non-neoplastic pathology were examined. Tumours showed molecular alterations for p16 gene and chromosome 9 abnormalities in, respectively, 29/31 and 19/31 cases respectively. p16 protein was unexpressed in 29/31 cases. In morphologically normal bronchi p16 gene and chromosome 9 alterations occurred in, respectively, 13/31 and 4/31 cases respectively; loss of protein immunoreactivity occurred in 14/31 cases. No alterations were seen in any of the control cases.

CONCLUSIONS

Inactivation of p16 gene in histologically normal bronchi could aid the identification of individuals at risk of developing SCC of the lung.

Two sisters with multiple sclerosis, lamellar ichthyosis, beta thalassaemia minor and a deficiency of factor VIII

Two of four sisters have multiple sclerosis (MS), lamellar ichthyosis, beta thalassaemia minor and a quantitative deficit of factor VIII-von Willebrand complex. The mother and the other sisters have only beta thalassaemia minor. The association of MS and a cluster of genetically determined diseases is rare. Such families could offer a new approach to the investigation of the polygenetic background of MS.

Ki67 immunohistochemical evaluation in colorectal cancer and normal colonic mucosa. Possible clinical applications

Cell proliferation was evaluated by Ki67 monoclonal antibody in 33 colorectal adenocarcinomas and in the normal colonic mucosa. Immunoreactivity was assessed independently by two observers in two subsequent evaluations with a semiquantitative method, by counting at least 2000 cells in two distinct neoplastic specimens (central and peripheric section). There was an excellent intra-inter observer agreement in Ki67 score for each specimen. The tumor score range from 7 to 70% (median 48.8), without any significant correlation with sex and age of the patient and location, size, staging and grading of the neoplasm. Tumor Ki67 score was almost identical in central (46.96%) and in peripheral section (49.24%), and always higher than in normal mucosa. There was no distinction in Ki67 score in normal mucosa at various distances from the tumor. In our experience, Ki67 provides a reliable and reproducible method for assessment of proliferative activity; its clinical applications need further studies.

PNA: a marker of neoplastic progression and differentiation in the gastro-intestinal tract

We examined 35 cases of stomach carcinoma and 40 cases of colonic carcinoma with PNA associated with peroxidase (peanut agglutinin, lectin which binds to the terminal disaccharide galactose beta (1,3)-N-acetil-galacto-samine). In this way evaluation of the functional aspects of the normal-neoplastic sequence was undertaken. This method was carried out for histological and ultrastructural investigations. The results obtained in both cases showed a different reactivity in the evolution of neoplastic disease: in fact, positivity in dysplasia is finely granular intracytoplasmic, whereas in well-differentiated neoplastic transformation such a reactivity is preferentially localized along the cellular membranes, with restoration of gross positivity in the cytoplasm for the poorly-differentiated neoplasm. We therefore believe PNA to be a marker not only of neoplastic progression but of differentiation as well: we also hypothesize it to reveal glycoprotein groups with possible antigenic power, involved in immunologic interactions between tumor and host.