Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001175 (AIDS)
 120,706 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Primary central nervous system lymphoma (PCNSL) is a rare tumor but it is rising in incidence in both AIDS and non AIDS populations. It is a non-Hodgkin's lymphoma that usually presents itself as a brain tumor, but leptomeninges, eyes and also spinal cord are frequently affected. The management of PCNSL patients has evolved in the last years. The role of surgery has been restricted for diagnosis only because the exeresis of the tumor is ineffective owing to its multifocal and infiltrative nature. Therefore, stereotactic biopsy is the way of choice for documenting the diagnosis. The standard treatment was radiotherapy started after diagnosis and followed by chemotherapy at recurrence. PCNSL is radiosensitive and chemosensitive: about 70% of patients respond to one or other of these treatment modalities but usually PCNSL recurs locally after radiotherapy. More recently the inclusion of high doses ARA-C and Methotrexate delivered prior radiotherapy have shown significant high responses and prolonged survivals.
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PMID:Primary cerebral non-Hodgkin's lymphoma (PCNSL): a review of new trends in management. 911 36

Biology of HIV-1 associated neoplasias is modulated by viral and host factors. In addition the development of tumors and their response to therapy may be further influenced by long-term treatment of HIV-1 patients with nucleoside analogs such as AZT (3'-azido-3'deoxythymidine), ddI (2',3'-dideoxyinosine), ddC (2',3'-dideoxycytidine), d4T (2',3'-didehydro-2'3'-dideoxythymidine), and 3TC [(-)-beta-L-2',3'-dideoxy-3'-thiacytidine] alone or in combination. As these compounds can trigger mechanisms involved in chemoresistance, we tested whether prolonged in vitro treatment of H9 cells (T-cell lymphoma) with AZT alters sensitivity of lymphoma cells to antitumor agents used for AIDS-associated malignancies. H9 cells grown for more than two years in medium containing 250 microM AZT developed resistance to the toxic effects of AZT while retaining sensitivity for other nucleoside analogs including ddC or cytosine arabinoside (ARA-C). These cells designated H9rAZT250 were 2 to 10-fold less sensitive to the toxic effects of antitumor agents, including cisplatin (CDDP), vincristine (VCR), doxorubicin (DOX) and etoposide (VP-16), when compared with parental H9 cells. The resistance of H9rAZT250 cells to antitumor agents was associated with inhibition of apoptosis as demonstrated by ultrastructural investigations and DNA-fragmentation assay (ELISA). The expression of the antiapoptotic gene bcl-2 was increased in H9rAZT250 cells while expression of other genes involved in the regulation of apoptosis such as c-myc, p53 and Fas was not changed. These results demonstrate that prolonged in vitro treatment of H9 lymphoma cells with AZT results in the development of resistance to antitumor agents in association with inhibition of apoptosis and increased expression of bcl-2. Therefore AZT long-term treatment of some HIV-1 patients with malignancies may have affected behavior of tumor cells including response to therapy.
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PMID:Azidothymidine resistance of H9 human T-cell lymphoma cells is associated with decreased sensitivity to antitumor agents and inhibition of apoptosis. 985 Jul 37