Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cellulose acetate (CA) discs placed in the peritoneum of mice become coated by a layer of peritoneal cells consisting primarily of macrophages (M). These CAM support the growth of hematopoietic colonies when syngeneic bone marrow cells are injected intraperitoneally. Most of these colonies are granulocytic and are recognizable by their peroxidase reaction. Since silica and carrageenan are known to reduce macrophage function, their effect on CAM granulocyte colony formation was tested. Carrageenan injected intraperitoneally before, concurrently, or after injection of marrow cells markedly reduced colony formation. Silica injected intraperitoneally concurrently or after injection of marrow cells reduced colony formation. Silica injected before marrow cells did not reduce colony formation. CAM produced in one mouse and exposed to carrageenan or silica in situ for 24 h before being transferred to sublethally irradiated recipients and seeded by injection of marrow cells had control levels of granulocytic colonies. Likewise, CAM produced in one mouse, removed, incubated in vitro with carrageenan or silica, carefully rinsed and transferred to sublethally irradiated recipients and seeded with marrow cells were able to support control levels of colony formation. Intravenous injection of silica or carrageenan had no consistent effect on colony formation. Spleen colonies (CFU-S) from marrow cells incubated in vitro with the agents, and given intravenously to lethally irradiated mice, were inhibited by silica, but not by carrageenan. Silica or carrageenan given intravenously to irradiated mice 3 h before or 3 h after intravenous marrow cell injection enhanced subsequent CFU-S formation.
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PMID:Influence of silica and carrageenan on spleen colonies and colonies in murine peritoneal cell-coated cellulose acetate membranes. 629 99

A comparative study of non-specific immunosuppression by malaria has been carried out in five situations: in both unvaccinated and vaccinated mice infected with the lethal Plasmodium yoelii or the lethal Plasmodium berghei, and in the unvaccinated non-lethal P. yoelii infection. Spleen cells showed a suppressive effect on the normal blastogenic response to mitogens. This suppression was strongest in the mice vaccinated before infection with the lethal P. yoelii and in those infected with non-lethal P. yoelii, suggesting that the suppressive effect did not interfere with recovery. Silica, anti-Thy-1, and indomethacin treatment suggested that this suppression was caused by macrophages. However, the plaque-forming cell response to sheep RBC in vivo was suppressed equally in every case at the peak of the parasitaemia, whereas the suppression of contact sensitivity to oxazolone was strongest in mice with fatal infections. We suggest that different suppressor mechanisms operate in malaria, some being harmful to the host and others possibly beneficial.
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PMID:Two distinct types of non-specific immunosuppression in murine malaria. 701 9