Morphological injury of the intestinal mucosa and infection in patients with AIDS. The role of combined tissue and stool examination.

AIMS: To define the relationship between morphological injury of the intestinal mucosa and infections in AIDS patients. METHODS: Forty-nine AIDS patients were examined by upper gastrointestinal (GI) endoscopy and 8 of them also by lower GI endoscopy. Biopsy specimens, taken from the lower duodenum, esophagus and rectum, were studied by light (L.M.) and transmission electron microscopy (T.E.M.). Stool examination for microorganisms was routinely performed in all patients. RESULTS: Microorganisms were detected in 37 of the 49 patients (75.5%) by combined tissue and stool examination. The histological study revealed villous atrophy, inter- and intra-enterocyte oedema and epithelial degenerative changes in most of the patients whether or not they had detectable microorganisms. CONCLUSIONS: Combined methods (endoscopy, L.M. and T.E.M., studies of tissue samples, microbiological study of stool samples) may be used to improve the documentation of infections and morphological injury of the intestinal mucosa in AIDS patients.

p53 oncoprotein expression in parotid gland carcinoma is associated with clinical outcome.

BACKGROUND: Recent studies of the molecular biology of cancer have demonstrated that p53 tumor suppressor gene aberration is associated with the development and progression of several different cancer types. METHODS: To analyze the expression of the p53 oncoprotein in parotid gland neoplasms, 72 parotid gland tumors (including 46 malignant and 26 benign cases) were studied immunocytochemically using the murine monoclonal DO-7 anti-p53 antibody. In parotid gland cancers, no and low expression (-/+) or moderate and high expression (++/+++) of the p53 oncoprotein were examined for correlation with patient survival and other clinicopathologic features, including clinical stage, tumor size, regional lymph node status, facial nerve paralysis, local infiltration, and distant failures. RESULTS: Positive staining was observed focally in 3 of 26 (11%) benign tumors and in 31 (67%) of 46 malignant tumors. Cancers showing moderate and high expression of p53 tended to be more advanced and larger than those with no expression or low expression, and presented at diagnosis more frequently, with signs of local aggressiveness. Tumors with moderate and high expression of p53 were associated more frequently with regional and distant metastases (P = 0.07 and P = 0.004, respectively). Multiple logistic regression analysis showed that regional and distant metastases were associated independently with p53 expression (P = 0.068 and P = 0.047, respectively). Moreover, patients whose cancers had moderate or high p53 expression had lower disease free and overall actuarial survival rates than those with no or low p53 expression (P = 0.021 and P = 0.033, respectively). Univariate and multivariate analysis confirmed the independent predictive prognostic value of p53 expression in patients with parotid gland cancer (P = 0.044 and P = 0.039, respectively). Furthermore, p53 expression did not correlate positively with patients' smoking habits in this series. CONCLUSION: The p53 tumor suppressor gene may be involved in salivary gland carcinogenesis, and its oncoprotein expression is an independent indicator of clinical aggressiveness in patients with carcinoma of the parotid gland.

[Expression of p53 in the skin in systemic sclerosis. Immunohistochemical study of 8 cases]. / Espressione della p53 nella cute di sclerosi sistemica. Studio immunoistochimico di otto casi.

P53 gene belongs to the family of "Tumor suppressor gene". It encodes a nuclear phosphoprotein involved in cell proliferation control; mutations of p53 gene are the most common genetic alterations found in human tumors. These mutations may cause the production of an altered protein that usually loses its physiological function. The mutant p53 protein is more stable than the wild type form and it is immunohistochemically detectable. Systemic Sclerosis is characterized by activation of fibroblasts, endotheliocytes and lymphocytes; furthermore, in this disease, a proto-oncogenic activation has already been shown in fibroblasts and lymphocytes. The aim of this study was to verify p53 expression in the skin of SSc patients. Eight patients, all classified in the limited cutaneous subset of SSc, after informed consent, underwent skin biopsies of the affected and apparently unaffected skin. P53 was investigated by immunohistochemistry, using a monoclonal anti-p53 antibody (DO-7), on formalin fixed, paraffin embedded tissue. P53 immunoreactive cells were found in 4 out of 8 biopsies; in all cases the positivity was confined to cells of the basal layer of the epidermis, histologically identified as keratinocytes. A large case series and a molecular biology approach are needed to support these preliminary observations.

p53 protein overexpression in a case of conjunctival micro-invasive carcinoma.

We analysed by immunohistochemistry the expression of p53 protein in a case of micro-invasive carcinoma of the conjunctiva. About 50% of tumor cells showed a strong nuclear positivity for p53. This suggests that p53 gene alterations play a role in the development of this type of tumor.

HPV and p53 in urinary bladder carcinoma.

We report a study on human papilloma virus (HPV) and p53 protein in 18 cases of urothelial carcinoma grade 1, 2 and 3. The presence of HPV has been correlated to the p53 protein expression, as this virus, once integrated in the cell nuclei, seems to cause the alteration of some genes expression, involved in the cell-cycle regulation, like p53. One case of urothelial papillary carcinoma grade 2, infiltrating the lamina propria, resulted to be positive for HPV type 31/33/51 and for p53 protein. Our data suggest that HPV type 31/33/51 may have played a role in the pathogenesis of this neoplasia causing an alteration of p53 gene.

Expression of retinoblastoma protein in human breast cancer: an immunohistochemical study.

The product of the human retinoblastoma gene (pRb) is a nuclear phosphoprotein that is thought to function as a tumor suppressor. Heterogeneous expression of the Rb gene product contributes to the genesis of a diverse group of human neoplasma such as breast, prostate, small cell lung, bladder carcinomas and leukemia. The clinical importance of Rb function demands a reproducible Rb immunohistochemical assay to distinguish Rb+ from Rb- tumor cells. We report an immunohistochemical study to detect Rb protein in a series of 50 invasive breast cancers. Our results support the hypothesis that the Rb gene functions as both a cell growth factor and a tumor suppressor.

[Pseudo-Whipple disease caused by atypical mycobacteriosis in AIDS: a clinical and electron microscopic study of 2 cases]. / Pseudo-malattia di Whipple da mycobatteriosi atipica in AIDS: studio clinico ed elettromicroscopico di due casi.

The Authors focus on two cases, studied by electron and light microscopy, of Whipple-like disease caused by atypical mycobacteria in AIDS. Differential characteristics between the cases and classical Whipple's disease are analyzed with regard to the diagnostic and therapeutical peculiarities of Mycobacterium avium-intracellulare infection which accounts for over 80% of atypical mycobacterial infections in AIDS. In this regard the Authors stress the role of histological findings of pale blue striated histiocytes as a marker of Mycobacterium avium-intracellulare infection.