Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038002 (splenomegaly)
 9,873 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The histopathology of the thymus and spleen and the response of spleen cells to mitogenic stimuli were evaluated in Sprague-Dawley CF-1 mice infected with Ehrlichia risticii. Intraperitoneal injection of 10(4) or 10(6) E. risticii-infected U-937 cells into mice resulted in 100% morbidity and partial mortality. Thymic atrophy became significant between 1 and 2 weeks postinfection and remained for the duration of the study. The atrophy appeared associated with antecedent destruction and rarefaction of lymphocytes, resulting in the loss of corticomedullary demarcation. Splenomegaly was prominent; significantly increased weights were detected 7 days postinfection. Histopathologic examination revealed rarefaction of lymphocytes around central arteries, the presence of necrotic debris in histiocytes, and replacement of erythropoiesis by granulopoiesis in the red pulp. Marked and acute reduction of in vitro proliferative responses of spleen cells to concanavalin A (ConA) and phytohemagglutinin were observed in mice infected with 10(4) or 10(6) E. risticii-infected U-937 cells. Interleukin-2 activity in the supernatant of ConA-stimulated spleen cells was also severely reduced. Both changes were time- and dose-dependent and were not associated with decreased spleen cell viability. Neither morbidity nor mortality occurred in mice infected with 10(2) E. risticii-infected U-937 cells. Although there was temporal reduction in phytohemagglutinin-driven lymphocyte proliferation, reduction in neither ConA-driven lymphocyte proliferation nor interleukin-2 activity was observed with this dosage. All E. risticii-inoculated mice seroconverted between days 18 and 25, as detected by the indirect fluorescent-antibody procedure. The findings indicate for the first time the hypoimmune responsiveness and histopathologic changes in lymphoid organs associated with E. risticii infection.
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PMID:Reduced immune responsiveness and lymphoid depletion in mice infected with Ehrlichia risticii. 349 79

Hairy cell leukemia (HCL), a rare haematological disorder of B-cell origin, mainly presents with bone marrow infiltration, haematopoietic insufficiency, and splenomegaly. In some cases, osteolytic lesions can be observed. Many of these clinical features, especially haematopoietic insufficiency and osteolytic lesions are likely to be caused by soluble factors, such as cytokines. There is evidence that these factors are produced by the malignant hairy cells themselves, suggesting a paracrine pathway. The importance of autocrine as well as paracrine growth loops in growth regulation of HCL-cells is supported by a series of excellent studies, performed within the last few years. It could be clearly shown that cytokines are involved in this autocrine and paracrine regulatory process. The most important cytokines which should be mentioned in this respect are tumor necrosis factor alpha, (TNF alpha). Interleukin-2 (IL-2), Interleukin-4 (IL-4), Interleukin-6 (IL-6) and B-cell-growth factor (BCGF). The role of other factors such as viruses and oncogenes remains rather unclear. Nevertheless, recent data suggest that the c-fms, which encodes for the macrophage colony stimulating factor (M-CSF) may be involved in the pathophysiological control of HCL growth. In this review, we summarise the important data and studies performed recently which shed light on the complex network of autocrine and paracrine growth regulation of HCL.
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PMID:Autocrine and paracrine regulation of neoplastic cell growth in hairy cell leukemia. 754 30

Interleukin-2 (IL-2) receptor gamma chain-deficient mice with a truncated mutation showed the absence or severe reduction of natural killer cells, decreased numbers of T- and B-cells, marked hypoplasia of the thymus and peripheral lymphoid tissues, defective formation of lymphoid follicles and germinal centre in the peripheral lymphoid tissues, and the absence of Peyer's patches in the intestinal mucosa. In addition, marked splenomegaly with extramedullary haematopoiesis, increased level of IgM and decreased levels of IgG and IgE in serum, severe reduction of conventional B cells (B-2) in the peripheral lymphoid tissues, the presence of IgM-producing CD5+ B cells (B-1) and their differentiation into plasma cells and Motto cells in the spleen, and increased production and differentiation of macrophages in various tissues were found in the mutant mice. However, the development of both marginal metallophilic macrophage populations in the spleen and of their related macrophages in the other tissues of the mutant mice was severely impaired. All these abnormalities seem to be induced by the loss-of-function of the IL-2 receptor gamma chain. From 8 weeks of age on, inflammatory changes occurred in the intestines, mesenteric lymph nodes, lungs, liver, and kidneys of the mutant mice. Besides the absence of Hassall's corpuscles, thymic cysts were frequently observed in the mutant mice. These pathological abnormalities suggest that the gamma chain is implicated not only in lymphoid and haematopoietic development but also in thymic epithelial cell ontogeny.
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PMID:Lymphohaematopoietic abnormalities and systemic lymphoproliferative disorder in interleukin-2 receptor gamma chain-deficient mice. 930 21