objective(s): we investigated the contribution of gyra and parc mutational mechanism in decreased ciprofloxacin susceptibility of acinetobacter baumannii isolated from burn wound infections. materials and methods: ciprofloxacin susceptibility of 50 a. baumannii isolates was evaluated by disk diffusion and agar dilution methods. pcr and sequencing were performed for detection of mutation in gyra...

as the turbine industries need to manufacture turbine blades made of martensitic stainless steel aisi 420 with high toughness and wear resistance, local laser hardening has become more and more important. in this research, surface of the samples was initially hardened by high-power pulsed laser beam; then, optimum parameters of hardening were calculated and wear resistance of surface hardened s...

Background. Alterations in expression of hepatic genes that could contribute to resistance to dietary cholesterol were investigated in Sprague-Dawley rats, which are known to be resistant to the serum cholesterol raising action of dietary cholesterol. Methods. Microarray analysis was used to provide a comprehensive analysis of changes in hepatic gene expression in rats in response to dietary ch...

The HSQC NMR spectrum of 15N-cisplatin in cell growth media shows resonances corresponding to the monocarbonato complex, cis-[Pt(NH3)2(CO3)Cl](-), 4, and the dicarbonato complex, cis-[Pt(NH3)2(CO3)2](-2), 5, in addition to cisplatin itself, cis-[Pt(NH3)2Cl2], 1. The presence of Jurkat cells reduces the amount of detectable carbonato species by (2.8+/-0.7) fmol per cell and has little effect on ...

The mechanism of chloramphenicol resistance in several multiple-resistant Staphylococcus epidermidis strains has been studied and shown to be due to the presence of the enzyme, chloramphenicol acetyltransferase. As with S. aureus, the inactivating enzyme in S. epidermidis appears to be the product of a structural gene on the chloramphenicol plasmid because resistance and enzyme activity are con...

Quinolones are one of the most commonly prescribed classes of antibacterials in the world and are used to treat a variety of bacterial infections in humans. Because of the wide use (and overuse) of these drugs, the number of quinolone-resistant bacterial strains has been growing steadily since the 1990s. As is the case with other antibacterial agents, the rise in quinolone resistance threatens ...

uridylic acid. The increase in the metabolic activity of a mutant is a reflection of the extent to which the corresponding analog is converted to the active intermediate. No differences in the rate of uptake of 5-fluorouracil were observed between the sensi tive or resistant strains. Resistance to a fluoropyrimidine is accompanied by com plete cross-resistance to the less potent fluoropyrimidin...

OBJECTIVES To determine the mechanism of trifluoromethionine resistance in Entamoeba histolytica and evaluate the impact of acquired drug resistance on virulence. METHODS Trifluoromethionine-resistant amoebae were selected in vitro and examined for cross-resistance to antiamoebic drugs, stability of resistance, methionine γ-lyase (MGL) activity, cell adhesion and virulence. Targeted gene sile...

Multidrug resistance is recognized as the key factor of many anticancer drugs invalidity. Anticancer treatments such as chemotherapy or radiation must hit their cellular targets and then cause cellular alteration or damage. However, in most cases the damage inflicted by the anticancer agent triggers apoptosis 1. Acute lymphoblastic leukemia (ALL) is the most frequently occurring cancer in child...