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)

Morphological changes in spleen and lymph nodes of C57B1 mice induced by the cytotoxic agent cyclophosphamide and the polysaccharide levan, separately and in combination were studied. In the spleen, an early decrease (phase 1) and a late increase (phase 2) in weight were found to result from all drug administrations. The hypocellularity of phase 1 was due to a depletion in the white pulp affecting mainly the B-region. Splenic weight decrease was parallel to B-cell depletion and most marked in animals exposed to cyclophosphamide with levan. The splenomegaly observed during phase 2 with all treatments was due to extramedullary hematopoiesis in the red pulp. In the lymph nodes, administration of cyclophosphamide and levan produced opposite effects on the B-cell region: cyclophosphamide eliminated the germinal centers for 8 days, but levan seemed to enhance B-cell activity. In animals given both cyclophosphamide and levan, inhibition of B-cell activity began earlier than with cyclophosphamide alone. Levan does not antagonize the suppressive effect of cyclophosphamide on the B-cell component at the early phase when the drugs are given together.
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PMID:Histological changes in spleen and lymph nodes of mice administered cyclophosphamide and levan. 348 27

The effect of the spleen on the efficiency of chemotherapy (cyclophosphamide) and immunotherapy (the polysaccharide levan) of C57BL mice bearing the Lewis lung carcinoma was studied. The development of Lewis lung carcinoma caused a gradual splenomegaly in the C57BL mice. Splenectomy did not, however, affect tumor growth in the nontreated host. Levan induced a pronounced splenomegaly. Splenectomy reduced markedly the antitumoral effect of the polysaccharide. These results indicate that spleen elements participate in the inhibitory activity of levan. By contrast, splenectomy had no effect on the efficiency of treatment of cyclophosphamide.
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PMID:Effect of splenectomy on treatment of Lewis lung carcinoma by an immunomodulatory polysaccharide and a cytotoxic agent. 356 Sep 64

Immunotherapeutic agents are often reported to induce opposite effects -- inhibitory and stimulatory -- on tumor growth, depending on the dose, timing or route of administration of the drug. The reason underlying these opposite effects is not yet known. The immunomodulatory polysaccharide levan (polyfructose) has been found to exert such opposite effects on the growth of the F10 variant of B16 melanoma. Low doses inhibit and high doses enhance tumor growth. Cyclophosphamide (CY) augment the inhibitory effect of levan. In order to clarify the mechanism of this switch, we tried in the present study to determine the changes induced by levan at inhibitory and stimulatory treatments, alone or with CY, on the morphology of spleens and lymph nodes of the melanoma-bearing mice. The growth of the tumor in non-treated mice was found to induce a moderate splenomegaly. Microscopically, two main changes were observed: a mild extramedullary hematopoiesis and a sharp increase in the number of germinal centers. A parallel increase in germinal center number was found in the lymph nodes. The data presented suggest that the immune system plays a role in both the inhibition and stimulation of tumor growth by levan. Levan induced a dose dependent splenomegaly, even more pronounced in combination with CY, due to an extramedullary hematopoiesis. Levan reduced the B cell activity caused by the tumor, proportionally to its dose. In combination with CY, levan accelerated the recovery of the B cell activity at the low dose, while the high dose prevented it. A similar trend was found in the lymph nodes. The changes involved in the switch inhibition-stimulation could be either the degree of reduction in B cell activity or the degree of extramedullary hematopoiesis or some interplay between the myelocytic and lymphocytic series, which was found to change in an opposite fashion under the influence of various treatments. Since the immune system is a finely equilibrated system, it is possible that immunomodulation rather than immunostimulation should be aimed at in cancer immunotherapy. However, the conditions required for achieving this equilibrium have to be defined.
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PMID:Effect of tumor inhibitory and stimulatory doses of levan, alone and in combination with cyclophosphamide, on spleen and lymph nodes. 374 40