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Biomedical subjects

D Benharroch

Publications and source records attributed to D Benharroch.

59 records · Page 4Linked to original sources
PubMed1987

Restoration of immunological responses by THF, a thymic hormone, in mice infected with murine cytomegalovirus (MCMV).

Cytomegalovirus causes T cell immune impairment in infected mice, reflected by a decreased response to the T cell mitogens PHA and Con A, and reduction of Con A-induced IL-2 secretion. Concomitantly, a marked increase in the spleen weight of infected mice was found. Histological examination of the liver revealed focal hepatitis. These signs of infection lasted from day 5 to day 14 after infection when mice slowly started to recover. Systemic treatment of MCMV-infected mice with thymic humoral factor (THF) resulted in a reconstitution of the mitogenic responses, IL-2 secretion, normalization of spleen weight and recovery of liver inflammation. Unlike other thymic hormones, THF did not affect interferon synthesis and NK cytotoxicity in infected mice. It is concluded that THF restores immune competence of mice immunosuppressed as a result of MCMV infection, through modulation of the T cell compartment.

Animals↗
PubMedDate not supplied

A comparison of distinct modes of tumor cell death in Hodgkin's disease using morphology and in situ DNA fragmentation.

The study examined the morphology and frequency of cell death occurring spontaneously in lymph nodes from patients with Hodgkin's disease. In addition to necrosis, which was infrequent and usually in patches, we document two cell types showing features of individual cell death: mummy cells end apoptotic cells. Mummy cells present no evidence of DNA fragmentation, but show electron microscopic features of "dark cells." Apoptotic Hodgkin-Reed-Sternberg cells are found frequently and are easier to demonstrate by in situ and labeling of fragmented DNA than by light microscopy only. In many cases phagocytosis of apoptotic cells is also documented. The significance of these findings to the limited number of Hodgkin-Reed-Sternberg cells in most cases of Hodgkin's disease is discussed.

Cell Death↗
PubMedDate not supplied

Phosphotyrosine, p62 c-myc and p21 c-Ha-ras proteins in colonic epithelium of normal and dimethylhydrazine-treated rats: an immunohistochemical analysis.

In the present study we used monoclonal antibodies to investigate the expression of phosphotyrosine, c-myc and c-Ha-ras proteins along the crypt continuum of normal and transformed rat colon tissue. Colon cancer was induced by administration of dimethylhydrazine. Particular attention was focused on the immunohistochemical pattern of murine colon mucosa during preneoplastic stages so as to permit the identification of putative changes in the expression/location of the oncoproteins prior to frank neoplasia. The immunohistochemical analysis of tyrosinephosphorylated proteins in the normal rat indicated that positive staining was mostly restricted to the lower colonic crypt zones. The carcinogenetic insult altered the magnitude and positional profile of phosphotyrosine along the colon crypt axis during the preneoplastic period. An intense positive reaction was observed in the upper crypt regions. Four weeks following the last DHM administration, viz. before tumor appearance, positive staining was evident in invasive adenocarcinoma tissue. In contrast to phosphotyrosine, the feeble c-myc immunohistochemical staining of normal rat colonic did not exhibit a focal topology. However, following DMH administration and prior to frank neoplasia, a substantial increase in the staining intensity for c-myc was noted, confined mostly to the supranuclear region of luminal cells. Invasive adenocarcinomas displayed intense cytoplasmic c-myc immunoreactivity. p21 c-Ha-ras expression and location along the colon crypt axis showed a different pattern when compared to p62 c-myc and phosphotyrosine. The p21 c-Ha-ras protein was prominently expressed in surface epithelium of normal and DMH-treated rats. Midcrypt colonocytes exhibited moderate p21 ras staining; in contrast, proliferating colonic cells resident in the lower crypt regions were consistently negative. These results suggest that c-Ha-ras gene product plays an important contributory role in determining the differentiated phenotype of the colonic cell.

1,2-Dimethylhydrazine↗
PubMedDate not supplied

Interleukin-1 and tumor necrosis factor-alpha in the Reed-Sternberg cells of Hodgkin's disease. Correlation with clinical and morphological "inflammatory" features.

We examined paraffin sections for the expression of interleukin-1 alpha, interleukin-1 beta and tumor necrosis factor-alpha, in 40 cases of Hodgkin's disease. Our purpose was to study the role of these cytokines in the "inflammatory" histological features and "B" symptoms in this disease. Immunohistochemistry with the avidin-biotin-peroxidase complex method was used. The findings were compared with those of 20 cases of non-Hodgkin's lymphomas and of 20 non-neoplastic lymphadenopathies. Evidence for EBV infection and myc and ras oncoproteins expression was also studied in these patients, but no correlation between any of these features and cytokine expression was found. We found a significant correlation between the expression of interleukin-1 beta and several "inflammatory" histological features, as well as between the expression of tumor necrosis factor-alpha and B symptoms and tumor bulk. The differential correlations between these major pro-inflammatory cytokines expression and the "inflammatory" manifestations in Hodgkin's disease are remarkable, considering the complexity of the cytokines composing the cytokine network involved in this disease.

Follow-Up Studies↗