The aim of this study was to investigate the influence of folylpolyglutamyl synthetase (FPGS) activity on the cellular pharmacology of the classical antifolates raltitrexed and methotrexate (MTX) using two human leukemia cell lines, CCRF-CEM and CCRF-CEM:RC2Tomudex. Cell growth inhibition and drug-induced inhibition of de novo thymidylate and purine biosynthesis were used as measures of the cel...

P-glycoprotein (Pgp) mediates drug accumulation defects in malignant cells in vitro. It confers resistance to multiple drugs including paclitaxel, an agent useful in treating malignancies including acute leukemia. Pgp-mediated drug resistance appears to be due to primary active drug-transport as well as other effects on membrane permeability, but the relative contribution of each is unclear. Fl...

Resumo Partindo da relação intrínseca entre teoria e etnografia, abordo neste artigo alguns dos motivos pelos quais, ainda hoje, Argonautas do Pacífico Ocidental é uma referência central para as ciências sociais. Precursor pesquisa de campo intensiva, Malinowski definiu diretrizes, favoreceu novas teorias, nutriu ideais, formulou utopias influenciou outras disciplinas das humanidades, tornando-...

We have shown that a glycoprotein(s) with a molecular weight of approximately 180,000 exists on the surface of cultured lymphoblasts selected for resistance to vinblastine (VLB) (CEM/VLB100). The amount of this glycoprotein, which is barely detectable on the VLB-sensitive cells (CEM), appears to be related in part to the degree of resistance, up to approximately 270-fold. Exposure of the cells ...

Contagious equine metritis (CEM) has given rise to international concern since it was first recognized as a novel venereal disease of equids in 1977 and the etiologic agent was identified as a previously undescribed bacterium, Taylorella equigenitalis. Horse industry concerns over CEM centered on the ease with which this bacterium could be disseminated, the significance of T. equigenitalis as a...

The HIV-1 Vif protein suppresses the inhibition of viral replication caused by the human antiretroviral factor APOBEC3G. As a result, HIV-1 mutants that do not express the Vif protein are replication incompetent in 'nonpermissive' cells, such as primary T cells and the T-cell line CEM, that express APOBEC3G. In contrast, Vif-defective HIV-1 replicates effectively in 'permissive' cell lines, suc...