The aim of the present study was to investigate the underlying mechanisms of methotrexate (MTX) resistance in the human osteosarcoma cell line, Saos-2/MTX4.4, and to evaluate various methods of overcoming the resistance to this chemotherapeutic agent. MMT assays were performed to determine the resistance of the primary (Saos-2) and resistant (Saos-2/MTX4.4) cell lines to MTX, cisplatin [cis-dia...

Because both Rhodamine 123 (R123) and hyperthermia have been shown to be cytotoxic, we examined their effect, independently and in combination, on five different human malignant cell lines in vitro and on cultured melanoma cells grown intradermally in nude mice. The cell lines examined include two human melanomas, UCLA-SO-M14 and UCLASO-M21, the colon cancer cell line HT29, the human lung cance...

Resistance to chemotherapeutic agents in neoplastic cells is often mediated by expression of P-glycoprotein, which functions as a drug-efflux pump for a broad range of substrates. We have used a combination of patch clamp and video-imaging techniques to examine the expression and drug-efflux function of P-glycoprotein and to determine the possible correlation with swelling-activated chloride ch...

In this work, the inversion scheme was used to determine the potential energy surfaces of five polar refrigerant mixtures. The systems studied here are R123-R134a, R123-R142b, R123-R152a, R142b-R134a, and R142b-R152a. The low-density transport coefficients of the refrigerant mixtures were calculated from the new invert potentials by the classical kinetic theory. The viscosity coefficient, binar...

A novel setup for fluorescence intensity and lifetime imaging (FLIM) of living cells is reported. Time-resolving techniques are combined with total internal reflection fluorescence microscopy (TIRFM), which permits optical excitation of either plasma membranes or whole cells depending on whether the angle of incidence of the excitation light is greater or smaller than the critical angle for tot...

Because both Rhodamine 123 (R123) and hyperthermia have been shown to be cytotoxic, we examined their effect, independently and in combination, on five different human malignant cell lines in vitro and on cultured melanoma cells grown intradermally in nude mice. The cell lines examined include two human melanomas, UCLA-SO-M14 and UCLA-SO-M21, the colon cancer cell line HT29, the human lung canc...

During hypoxia in the CA1 region of the rat hippocampus, spreading-depression-like depolarization (hypoxic spreading depression or HSD) is accompanied by both a negative shift of the extracellular DC potential (DeltaV(o)), and a sharp decrease in light transmittance (intrinsic optical signal or IOS). To investigate alterations in mitochondrial function during HSD and normoxic spreading depressi...

We have compared multiple assays for the P-glycoprotein (Pgp/MDR1) phenotype in fresh and thawed adult acute leukemia to validate and quantitate measures for the expression and function of Pgp. The results are related to the Pgp-expressing KB8 and KB8-5 call lines. The most sensitive assay was the measurement of modulation of the rhodamine 123 (R123) fluorescence by 2 micromol/L PSC833, followe...

Our goal was to quantify mitochondrial and plasma potential (Δψ(m) and Δψ(p)) based on the disposition of rhodamine 123 (R123) or tetramethylrhodamine ethyl ester (TMRE) in the medium surrounding pulmonary endothelial cells. Dyes were added to the medium, and their concentrations in extracellular medium ([R(e)]) were measured over time. R123 [R(e)] fell from 10 nM to 6.6 ± 0.1 (SE) nM over 120 ...

The increase in energy and environmental problems from day to has led us use sustainable methods of optimizing systems. In this study, mass flow rates, pressure ratios, net powers thermodynamic calculations were performed by adding the integrated organic rankine cycle (ORC) waste heat a gas turbine (GT) on behalf innovative concepts industrial competition operating five different fluids (R123, ...