Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acute radiation injury leads to thymic involution, adrenal enlargement, leukopenia, thrombocytopenia, gastrointestinal ulceration, and impaired wound healing. The authors hypothesized that supplemental vitamin A would mitigate these adverse effects in rats exposed to acute whole-body radiation. This hypothesis was based on previous experiments in their laboratory that showed that supplemental vitamin A is thymotropic for normal rodents and lessens the thymic involution, lymphopenia, and adrenal enlargement that follows stress, trauma, and neoplasia, largely obviates the impaired wound healing induced by the radiomimetic drugs streptozotocin and cyclophosphamide, lessens the systemic response (thymic involution, adrenal enlargement, leukopenia, lymphocytopenia) to local radiation, and shifts the median lethal dose (LD50/30) following whole-body radiation to the right. To test their hypothesis, dorsal skin incisions and subcutaneous implantation of polyvinyl alcohol sponges were performed in anesthetized Sprague-Dawley rats at varying times following sham radiation or varying doses of whole-body radiation (175-850 rad). In each experiment, the control diet [which contains about 18,000 IU vit. A/kg chow (3 X the NRC RDA for normal rats)] was supplemented with 150,000 IU vit. A/kg diet beginning at, before, or after sham radiation and wounding or radiation and wounding. The supplemental vitamin A prevented the impaired wound healing and lessened the weight loss, leukopenia, thrombocytopenia, thymic involution, adrenal enlargement, decrease in splenic weight, and gastric ulceration of the radiated (750-850 rad) wounded rats. This was true whether the supplemental vitamin A was begun before (2 or 4 days) or after (1-2 hours to 4 days) radiation and wounding; the supplemental vitamin A was more effective when started before or up to 2 days after radiation and wounding. The authors believe that prevention of the impaired wound healing following radiation by supplemental vitamin A is due to its enhancing the early inflammatory reaction to wounding, including increasing the number of monocytes and macrophages at the wound site; possible effect on modulating collagenase activity; effect on epithelial cell (and possible mesenchymal cell) differentiation; stimulation of immune responsiveness; and lessening of the adverse effects of radiation.
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PMID:Supplemental vitamin A prevents the acute radiation-induced defect in wound healing. 638 75

Since sinusoidal liver cells directly interact with circulating hemopoietic cells and lymphocytes, Kupffer cells may have the capacity to trap and activate these cells in the liver microcirculation. In order to investigate the adhesion mechanism of Kupffer cells to other lymphoid cells, mouse sinusoidal liver cells were isolated by a collagenase perfusion followed by differential centrifugations. By in vitro adhesion assay of lymphocytes to sinusoidal liver cells and staining of adhered lymphocytes with FITC/peroxidase labeled peanut agglutinin (PNA), the following observations were made: 1) Lymphocytes from various lymphoid organs including the liver itself adhered to Kupffer cells. 2) After an incubation period, DNA synthesis of the adhered lymphocytes increased. 3) A high percentage of the adhered lymphocytes were PNA+ cells. 4) D-Galactose, a PNA specific carbohydrate, inhibited the lymphocyte binding and the total DNA synthesis of the adhered lymphocytes decreased proportionally with their decrease in number. Our results suggest that sinusoidal liver cells may have the ability to trap and to activate PNA+ cells.
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PMID:Adhesive interaction between lymphocytes and sinusoidal liver cells. 811 51