The purpose of this work is to review the published studies on the mechanisms of action and resistance of 5-fluorouracil. The review is divided into three main sections: mechanisms of anti-tumor action, studies of the resistance to the drug, and procedures for the identification of new genes involved in resistance with microarray techniques. The details of the induction and reversal of the drug...

pretreatment of adults of iraq strain of afhstephenst with a sub-letlial dose of pcrmethrin resulted in a 65% enliancemenl of tolerance to this insecticide. similarly, pre-exposure of dub-lpr larvae to a sub-lethal dose of pcrmethrin resulted in increased tolerance to pcrmethrin. for the sensitive ind-s strain, the inductive effect was smaller. tiie results of bioassays of resistant and suscept...

objective(s):the colorectal cancer stem cells (cscs) with the cd133+ phenotype are a rare fraction of cancer cells with the ability of self-renewal, unlimited proliferation and resistance to treatment. quercetin has anticancer effects with the advantage of exhibiting low side effects. therefore, we evaluated the anticancer effects of quercetin and doxorubicin (dox) in ht29 cancer cells and its ...

Twenty isolates of Trichoderma harzianum wereisolated from the rhizosphere of healthy pistachio plants from different localities of Kerman Province, Iran.Five isolates with high antagonistic activity in in vitro assays against Verticillium dahliae (the causal agent of pistachio wilt), were investigated for their effect on the defense enzymes, peroxidase (PO), phenyl alanine-ammonia lyase (PAL) ...

Induction of resistance of oral anaerobes to the effects of human -defensin 1 (h D-1) to h D-4 was investigated by pretreating cells with either sublethal levels of defensins or environmental factors, followed by a challenge with lethal levels of defensins. Cultures of Porphyromonas gingivalis were (i) pretreated with defensins at 1 ng/ml, (ii) heated to 42°C (heat stress), (iii) exposed to nor...

The exposure of Staphylococcus aureus to a broad range of cell wall-damaging agents triggers the induction of a cell wall stress stimulon (CWSS) controlled by the VraSR two-component system. The vraSR genes form part of the four-cistron autoregulatory operon orf1-yvqF-vraS-vraR. The markerless inactivation of each of the genes within this operon revealed that orf1 played no observable role in C...