quinolones are a large and widely consumed class of synthetic drugs. expanded-spectrum quinolones, like ciprofloxacin are highly effective against gram-negative bacteria, especially escherichia coli. in e. coli the major target for quinolones is dna gyrase. this enzyme is composed of two subunits, gyra and gyrb encoding by gyra and gyrb, respectively. mutations in either of these genes cause qu...

Introduction: Antibiotic resistance, especially in Gram-negative uropathogens such as Escherichia coli, is the main barrier to treat urinary tract infection (UTI). In recent years, the dramatically increased resistance of E. coli to quinolones, a group of widely used antibiotics, has become a significant concern. Methods: In this descriptive cross-sectional study, we collected 261 E. coli isola...

Five rhesus monkeys were trained to discriminate the nonpeptidic, delta-opioid agonist SNC80 (0.32 mg/kg i.m.) from saline by using a food-reinforced drug-discrimination procedure. Cumulative doses of SNC80 produced a dose-dependent increase in SNC80-appropriate responding and a dose-dependent decrease in response rate. In time-course studies, peak effects of the training dose of SNC80 were obs...

Regioselective synthesis of quinolone-1,2,4-triazoles was established starting from 4-hydroxyquinol-2-ones. The strategy started by the reaction ethyl bromoacetate with 4-hydroxyquinoline to give corresponding oxoquinolinyl acetates, which reacted hydrazine hydrate afford hydrazide derivatives. Subsequently, hydrazides isothiocyanate derivatives acyl thiosemicarbazides. Finally, subjecting thio...

Resistance to the quinolones almost always arises from the accumulation of mutations in chromosomal genes responsible for the drug targets, permeability, or active efflux. This resistance can be depicted as a stepwise process in which each step, represented by separate mutations, diminishes susceptibility on average 4- to 8-fold. The precise path followed in this stepwise process differs with t...

This study evaluated bacterial etiology and antibiotic susceptibility in patients diagnosed with community-acquired perforated appendicitis over a 12-year-period. We retrospectively reviewed records of adult patients diagnosed with perforated appendicitis at an 800-bed teaching hospital between January 2000 and December 2011. In total, 415 culture-positive perforated appendicitis cases were ana...