We have evaluated whether selection of a human tumor leukemic line for resistance to vinblastine (Velban; VLB) alters its tumorigenicity. To address this question, CEM and CEM/VLB100 cells [which express the multiple drug-resistant (MDR) phenotype via amplification of the P-glycoprotein gene] were characterized by several techniques including chromosome banding, in situ hybridization, Southern ...

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 ...

BACKGROUND The luting cements must withstand masticatory and parafunctional stresses in the warm and wet oral environment. Mouth temperature and the temperature of the ingested foods may induce thermal variation and plastic deformation within the cements and might affect the strength properties. The objectives of this study were to evaluate the effect of temperature on the compressive and diame...

The aim of this study was to evaluate the in vitro color agreement between nanofluorapatite ceramic discs (e.max Ceram / Ivoclar Vivadent / A2) associated with try-in pastes and those bonded with resin cements (Vitique / DMG/ try-in shade A2½ and cement shade A2½, Variolink II / Ivoclar Vivadent / try-in shade A1 and cement shade A1, and Choice 2 / Bisco / try-in shade A2 and cement shade A2), ...

Physiological fluids will be in contact with the implant components from the first moments after a surgery. Therefore, the study of the effect of water on the properties of the bone cements that are part of the arthroplasty procedure is of critical importance to predict the long-term performance of the whole system. In our research group, we have developed a novel concept, the hydrophilic, part...

AIM To evaluate the physical and mechanical properties of two cements with a similar chemical composition to mineral trioxide aggregate and to attempt to improve their properties by producing a composite material. METHODOLOGY Two cement types were used: a mixture of calcium sulpho-aluminate cement and Portland cement (CSA) and calcium fluoro-aluminate cement (CFA) in conjunction with an admix...

statement of problem: calcium hydroxide which is commonly used as an intracanal medicament, changes the ph of dentin and periradicular tissues to an alkaline ph. in some clinical situations, endodontic reparative cements like calcium enriched mixture cement are used after calcium hydroxide therapy. however, the alkaline ph may affect the physical properties of this cement. objectives: this stud...

Glucocorticoids (GCs) induce apoptosis in lymphoid cells that contain functional GC receptors (GRs). However, GC resistance often is seen in cells with demonstrable GRs; one such line is CEM-C1. We have tested the hypothesis that positive interactions between GC and cyclic AMP (cAMP) regulate GC actions in CEM clones. Treatment of both GC-resistant CEM-C1 [resistant to 1 JIMdexamethasone (Dex)]...

Near diploid leukemic T-cells (LALW-2), exposed to cytotoxic drugs only as a consequence of therapy administered to the donor patient, have been maintained by serial xenograft in nude mice. In comparison with the leukemic line CCRF-CEM, using a growth inhibition assay, LALW-2 cells were resistant to Vinca alkaloids and actinomycin D (relative resistance, 200-fold or more), were slightly resista...