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...

Determinants of methotrexate (MTX) resistance in cell lines resistant to short, but not continuous, MTX exposure were investigated since such lines may have relevance to clinical resistance. CCRF-CEM R30dm (R30dm), cloned from CCRF-CEM R30/6 (a MTX-resistant subline of the CCRF-CEM human leukemia cell line), had growth characteristics similar to CCRF-CEM. R30dm was resistant to a 24-h exposure ...

Multidrug resistance (MDR) in leukemia patients is a great incentive to the development of new drugs. In a search for potential multidrug resistance modulators we tested a group of oleanolic acid (OA) analogues modified at C-3, C-11, C-12 and C-28 using an experimental model consisting of three human acute lymphoblastic leukemia cell lines (CCRF-CEM and the multidrug resistant sublines CCRF-VC...

The growth-inhibitory effect of fluoropyrimidines combined with a short-term exposure to leucovorin and the pattern of polyglutamylation of folates were compared between parental CCRF-CEM cells and a cell line with impaired ability to form polyglutamates (CCRF-CEM/P). The combination of leucovorin with 5-fluorouracil or 5-fluorodeoxyuridine increased the growth inhibition of CCRF-CEM cells comp...

The increase of vehicle in highways may cause traffic congestion as well as in the normal roadways. Predicting the traffic flow in highways especially, is demanded to solve this congestion problem. Predictions on time-series multivariate data, such as in the traffic flow dataset, have been largely accomplished through various approaches. The approach with conventional prediction algorithms, suc...

This study aimed to describe the development of types fishing gear in waters east coast Sumatra from Belawan Waters Serdang Bedagai and examine perceptions fishers based on social characteristics towards environmentally friendly Code Conduct for Responsible Fisheries (CCRF). The method used this research is descriptive using survey method. population were traps gill nets, as many 6943 people, w...

In protection experiments (5-formyltetrahydrofolate or 5-methyltetrahydrofolate added to cultures in vitro at the same time as methotrexate), 5-methyltetrahydrofolate af forded the same degree of protection as did formyltetrahydrofolate for phytohemagglutinin-stimulated peripheral blood lymphocytes and for methotrexate-resistant (R) and methotrexate-sensitive (S) sublines of CCRF-CEM. Either re...

A human T-lymphoblast cell line, CCRF-CEM/R1, resistant to methotrexate by virtue of increased dihydrofolate reductase activity, was grown in stepwise increasing concentrations of methotrexate. This additional selection pressure resulted in a cell line, CCRF-CEM/R2, resistant to methotrexate by virtue of both an elevation of dihydrofolate reductase activity and a marked decrease in methotrexate...

The mechanism of action of synthetic CCRF-DP, the corticotropin-releasing factor (CRF)-related diuretic peptide of the salt marsh mosquito Culex salinarius, was investigated in isolated Malpighian tubules of the yellow fever mosquito Aedes aegypti. A low concentration of CCRF-DP (10(-9)mol l-1) caused a small but insignificant increase in transepithelial secretion of NaCl and fluid, but signifi...

The aim of this study was to examine the effect of crude bile on the human HepG2 and CCRF-CEM cell lines. Cells were exposed to different dilutions of bile. Antiproliferative effects were determined by the cytotoxic MTT assay. Cells undergoing apoptosis were identified by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Bile administration resulted in dose-dependent c...