Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thirty-two patients were treated by ofloxacin on bacteriological documented infections. They were Enterobacterias: n = 15 (MIC less than or equal to 0.06 to 0.5 microgram/ml); Pseudomonas aeruginosa and Acinetobacter: n = 1 (MIC 0.5 and 4 micrograms/ml); Staphylococcus: n = 6 (MIC less than or equal to 0.06 to 4 micrograms/ml); Pneumococcus: n = 1; Mycoplasma: n = 1; Chlamydia psittaci: n = 2; Legionella pneumophila: n = 1; Rickettsias: n = 4 (three mediterranean fevers one query fever). Ofloxacin was given orally from 400 to 800 mg per day (5 to 15 mg/kg/day). It was used alone 26 times and on 6 occasions it was associated with rifampin on 6 staphylococcal infections. On 19 cases it was used after failure or intolerance of initial therapy. Thirty times it was the first antibiotic substance used. Results were good mainly: 1) on nine pneumonitis (enterobacterias: 4; Pneumococcus: 1; Mycoplasma: 1; Chlamydia: 2; Legionella: 1) during a mean duration of twenty days; 2) urinary infections (n:7) provoked by E. coli and Enterobacter cloacae (mean duration: 20 days); 3) 4 osteo-articular-infections (mean duration: 77 days); 4) Rickettsial infections (n:4) during a mean duration of 11 days. Results are particularly noteworthy because patients treated had severe infections: 12 bacteremias, 1 endocarditis and 1 purulent meningitis. None severe adverse effect was observed.
 ...
PMID:[Ofloxacin (RU 43280). Clinical study]. 330 73

The penetration of ofloxacin into bronchial secretions was evaluated in 16 patients after administration of a single oral dose of ofloxacin 400mg. Bronchial secretions were aspirated at bronchoscopy after 1 to 6 hours and serum was collected simultaneously. Ofloxacin concentrations were measured by a microbiological assay method. Considerable individual variations in serum and bronchial aspirate concentrations were recorded: bronchial aspirate concentrations varied between 1.1 mg/L and 4.5 mg/L but exceeded 1.5 mg/L in 14 of 16 patients between 1 and 6 hours. The ratio between simultaneous mean bronchial aspirate and serum concentrations ranged between 0.53 in the second hour and 0.92 in the fourth hour. It is likely that inhibitory activity will be sustained over at least 6 hours against most potential respiratory pathogens including Haemophilus influenzae, Branhamella catarrhalis, Gram-negative bacilli, Staphylococcus aureus, Legionella pneumophila and Mycoplasma pneumoniae. Streptococcus pneumoniae and Pseudomonas aeruginosa may have minimal inhibitory concentration (MIC) values lower than ofloxacin concentrations achieved in bronchial secretions, although some isolates are less sensitive. Clinical studies should establish the relevance of pharmacokinetic data to respiratory infections caused by organisms of borderline susceptibility.
 ...
PMID:Penetration of ofloxacin into bronchial secretions. 348 25

The antimicrobial activity of ofloxacin was tested against 15 standard strains and 37 clinical and environmental strains of Legionella pneumophila by agar dilution susceptibility studies with a new growth medium. The ofloxacin MICs were inoculum dependent and ranged from 0.03 to 0.125 microgram/ml. The antibacterial activities of other agents tested relative to ofloxacin were rifampin greater than ofloxacin greater than josamycin greater than pipemidic acid. Ofloxacin, at concentrations equal to or greater than 0.05 microgram/ml, inhibited the growth of L. pneumophila grown in human monocytes. The therapeutic efficacy of ofloxacin in experimental guinea pig L. pneumophila pneumonia was greater than that observed with erythromycin or josamycin therapy; it was less effective than was rifampin. Ofloxacin was very active against intracellular L. pneumophila in these experiments and should be studied in the therapy of human Legionnaires disease.
 ...
PMID:Susceptibility of Legionella pneumophila to ofloxacin in vitro and in experimental Legionella pneumonia in guinea pigs. 386 61

An agar dilution technique was used to compare the antimicrobial activities of lomefloxacin, norfloxacin, ofloxacin, ciprofloxacin and enoxacin against 544 strains of bacterial isolates. Among the five quinolone agents tested, ciprofloxacin was the most active. Enoxacin was the most active after ciprofloxacin against Escherichia coli, Enterobacter aerogenes, Proteus mirabilis, Shigella spp., Yersinia enterocolitica, and Haemophilus influenzae with an MIC90 of < or = 0.25 micrograms/ml. Ofloxacin was the most active agent after ciprofloxacin against Klebsiella pneumoniae, Enterobacter cloacae, Citrobacter diversus, and Legionella pneumophila with an MIC of < or = 0.25 micrograms/ml. Ciprofloxacin inhibited Staphylococcus spp. and Streptococcus spp., at < or = 0.5 micrograms/ml and 2 micrograms/ml, respectively. Norfloxacin and enoxacin had the same antimicrobial activity (MIC90) against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus agalactiae and some other Gram-positive species, but these activities were weak when compared with ciprofloxacin. The results of this in vitro study show that ciprofloxacin is very active against Gram-negative and Gram-positive species.
 ...
PMID:Comparative antimicrobial activity of lomefloxacin, norfloxacin, ofloxacin, ciprofloxacin and enoxacin against > 500 bacterial isolates. 839 96

Ofloxacin ((+/-)-9-fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-7-oxo-2, 3-dihydro-7H-pyrido[1,2,3-de]-1, 4-benzoxazine-6-carboxylic acid) is a totally synthetic fluoroquinolone antimicrobial agent with a broad spectrum of activity against Gram-positive and Gram-negative bacteria and atypical pathogens such as Mycoplasma, Chlamydia and Legionella. Even though it is widely used for the treatment of gastrointestinal, pulmonary, urinary, and other infections, the comprehensive mechanism of action at molecular level has not been known so far. It is very important to understand the structural characteristics of the drug and the effects that are caused by the environments. With the purpose of deeply investigating the structure of Ofloxacin, an analog of Ofloxacin, Methyl-Ofloxacin (Me-OFL), was synthesized by methylation of 4'N in piperazine ring from Ofloxacin with CH3I. Then appropriate Me-OFL was dissolved in DC1/D2O and NaOH/D2O to prepare corresponding acidic and alkaline solutions. Systematic NMR spectroscopic investigation on Me-OFL in both acidic and alkaline solution was conducted using quantitative 1H and 13C spectra, DEPT, HSQC together with HMBC techniques. The spectra were recorded with Bruker AM-300 spectrometer and DRX500 spectrometer. Chemical shifts have been given in values referred to dioxane (deltaJ = 3.7, deltac = 67.8). Complete assignments on 1H and 13C signals of Me-OFL were obtained in different pH environments where the coupling constant between 13 C and 19F was found to be very helpful for the assignment of aromatic 13C signals. A comprehensive comparison between the 1H, 13C chemical shifts, together with the structural transformation in acidic and alkaline solutions was made and discussed in details. Due to the formation of hydrogen bond between COOH and C==O, the COOH and aromatic ring are in the same plane. As a result, a weak O...H--C hydrogen bond forms between C==O from the carboxyl group and 5-H from aromatic ring. In alkaline solution, the deprivation of H+ from COOH destroys not only the hydrogen bond between COOH and carbonyl group but also the weak hydrogen between the C==O from COOH and 5H. As a result, the 5H exhibited remarkable shift toward high field (1.02). Meanwhile, the chemical shift of 6C, 13C, 7C, 15C also exhibited remarkable shift to low field at 12. 04, 7.46, 4.33, 2.88 respectively. Such variations were related to the changes of p electrons from carboxyl group caused by the transformation between the carboxyl group and the carboxylate group in different pH environments. Comparison of deltaH, deltac data between Me-OFL and OFL in acidic solution and OFL in alkaline was made. In Me-OFL acidic solution, the chemical shift of 3'C, 5'C, 7'C, 8'C also exhibited remarkable shift to low field at 6.66-7.32 respectively, the chemical shift of 2'C and 6'C also exhibited remarkable shift to high field 6.04. In OFL acidic solution, the chemical shift of 2'C, 3'C, 5'C, 6'C, 7'C, 8'C also exhibited remarkable shift to high field within 2.39, Comparison between the protonation and the methylation on the 4'N atom from the piperazine ring was also made. The distribution of positive charge also showed difference. When protonation occurred on the piperazine ring, the positive charge was on the proton connected with 4'N. However, if methylation occurred, the positive charge is on the 4'-N atom.
 ...
PMID:[A study on the NMR spectrum of methyl-ofloxacin]. 1880 Jul 40


<< Previous 1 2