Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hypoxanthine:guanine phosphoribosyltransferase (HPRT) activity was measured in 14 human osteosarcomas to test whether a subset of these tumors was deficient in the purine salvage pathway enzyme and thus provide a rationale for therapy with methotrexate-thymidine rescue. All tumors contained HPRT activity within the range previously reported for xenografts of human osteosarcoma. Three patients received methotrexate (3.375 g/m2/24 hours) as a 72-hour continuous infusion with thymidine rescue (2.0 g/m2/24 hours) beginning 24 hours after the start of the methotrexate infusion. The methotrexate-thymidine infusion was well tolerated by all patients with no significant toxicity; however, there were no responses. We conclude that osteosarcomas are not deficient in HPRT activity. Therefore, the previously reported rationale for therapy of osteosarcoma with methotrexate-thymidine based on lack of activity of this enzyme is not valid. This combination, although well tolerated, is inconvenient and requires prolonged hospitalization. Therefore, without a valid rationale it cannot be recommended for therapy of patients with osteosarcoma.
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PMID:Hypoxanthine:guanine phosphoribosyltransferase activity in primary human osteosarcomas. A rationale for therapy with methotrexate-thymidine rescue? 310 47