Non Hodgkin's lymphoma: an ultrastructural study

Lymph nodes from 18 patients with various grades of non Hodgkin's lymphoma [NHL] were studied before and during chemotherapy to determine the Ultrastructura1 morphologic alterations and the response of malignant cells to treatment. Some differences occurred regarding the relative incidence of the different histological subtypes after E.M. examination. During treatment, the lymph nodes revealed ultrastructural changes in the nucleus and cell organelles denoting good response to treatment. These results show that the ultrastructural examination permits a more refined evaluation of the cytological details and leads to more accurate diagnosis [especially in equivocal cases of various subtypes of lymphoma. This in turn will affect the line of treatment and the prognosis of the disease. Moreover, the electron microscope could be used as an indicator of the responsiveness of non Hodgkin's lymphoma to treatment

study of the sequence of changes in the lungs of rats chronically exposed to silica dust

Histopathological and enzyme histochemical changes were studied in lungs of rats chronically exposed to silica-bearing dust. The early histopathological changes were in the form of an inflammatory reaction consisting of polymorphonuclear neutrophils, macrophages and lymphocytes, while after prolonged exposure, lymphocytes and plasma cells predominated and the alveolar walls were thickened and showed increased deposition of recticulin and collagen fibres. These changes were accompanied by alteration in the activities of the phosphatase, non-specific esterase, succinic dehydrogenase and cytochrome oxidase enzymes in the alveolar and bronchilar epithelium and in the macrophages. The presented findings might lead to the suggestion that, following inahalation of silica-bearing dust, an inflammatory reaction develops in the lungs of the exposed animals. The stimulated macrophages release hydrolytic enzymes which produce destruction of lung parenchyma, hence antigenic material is released by the destroyed lung tissue evoking an immunological inflammatory reaction and thus augmenting the process of tissue destruction which precedes fibrogenesis

role of immunity in the pathogenesis of bladder cancer in association with bilharziasis

The iliac lymph nodes from 23 patients with bilharzial cancer bladder were histologically examined to evaluate the type of immunological response as correlated with changes in the cortical lymphoid follicles and medullary cords which are sites of B-lymphocytes and the paracortical area which is the site of T-lymphocytes. 73.91% of cases presented a pattern denoting humoral response and 17.39% of cases presented a pattern denoting both humoral and cell mediated response. 8.7% of cases were of the non-reactive pattern and non showed a "pure" cell mediated reaction. It is hypothesized that depression of cell mediated reactivity which naturally occurs in chronic bilharziasis may be an important contributing factor in the development of cancer of the bilharzial bladder which is the seat of chronic irritation by bilharzia ova and toxic products

Cells morphologically resembling strenberg-Reed cells in the lymph nodes of methotrexate treated schistosoma mansoni infected mice

Cells morphologically resembling Sternberg-Reed cells were identified in the mesenteric lymph nodes of mice, 12 weeks after infection with Schistosoma mansoni cercariae, and treated with methotrexate, an immunosuppressive agent. The presence of these cells was associated with augmented stimulation of the cortical B-lymphocytes [humoral immunity] and suppression of the paracortical T-lymphocytes [cell mediated immunity]. The present observations help to throw more light on the mechanisms involved in the evolution of Sternberg-Reed cells, and bear a warning to pathologists dealing with lymph node biopsies obtained from patients from areas where bilharziasis is endemic as they should be very cautious in diagnosing Hodgkin's disease when they encounter cells resembling Sternberg-Reed cells

Histopathological and histochemical studies on experimentally infected hamsters with pygidiopsis genata

Haematoxylin eosin stained sections showed the stunted growth of the villi as well as widening of the intervillous spaces in the regions where the worms were seen lodged. A focal cellular reaction was seen in the lamina propria. The enzymatic activity was markedly reduced in the villi in succinic dehydrogenase, nonspecific esterase and alkaline phosphatase; where as marked reduction in the activity of acid phosphatase was noticed particularly in the glands. Those changes suggest a disturbance in both digestive and absorptive mechanisms