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Biomedical subjects

A Bryskier

Publications and source records attributed to A Bryskier.

At least 91 records · Page 5Linked to original sources
PubMed1988

[Interaction of roxithromycin with human polymorphonuclear neutrophils in vitro and ex vivo].

Roxithromycin (RU 28965) a new semisynthetic macrolide has been reported to display an antibacterial spectrum and activity in vitro similar to those of others macrolides. However, roxithromycin seems more efficient than erythromycin in in vivo experimental infections (mice). We have previously reported that roxithromycin increases the ability of human neutrophils (PMN) for bactericidal activity (S. aureus) or phagocytosis (K. pneumoniae) in vitro without altering other PMN functional parameters. In this study, roxithromycin (single dose-300 mg) was given to 6 human volunteers. The neutrophils collected 90 min after ingestion display a significant increased ability to phagocytose and kill S. aureus and K. pneumoniae. Furthermore chemotaxis, oxidative burst and myeloperoxidase activity of the PMN after roxithromycin ingestion were enhanced compared to those of PMN before ingestion. This discrepancy between immunomodulating effect of roxithromycin in vitro and in vivo outlines the complexity of in vivo experimental models and requires further studies in vivo in particular in patients suffering from sepsis.

Adult↗
PubMed1988

[In vitro antibacterial activity of cefpirome in combination with 4 aminoglycosides and 2 fluoroquinolones].

Combinations of cefpirome with aminoglycosides (gentamicin, tobramycin, netilmicin, amikacin) and of cefpirome with fluorinated quinolones (pefloxacin, ofloxacin) were tested against 20 Enterobacteriaceae, 6 Pseudomonas aeruginosa, 6 Acinetobacter calcoaceticus, 6 group D Streptococci and 6 Staphylococcus aureus strains, susceptible, intermediate or resistant with a low level to these different compounds. Activity of combinations was evaluated using a broth microdilution checkerboard method and FIC indices determination. Combinations of cefpirome with aminoglycosides demonstrated a synergistic effect in 79.5% of cases, but a strong synergy (FIC less than or equal to 0.62) was observed in only 46% of cases. The higher rate of strong synergy concerned Enterobacteriaceae (50% of cases) and group D Streptococci (58.3%). Combination of cefpirome with gentamicin was the most active against Enterobacteriaceae and with a lower degree against P. aeruginosa, A. calcoaceticus and S. aureus. Combination of cefpirome with netilmicin was the best association against group D Streptococci. Combinations of cefpirome with fluorinated quinolones demonstrated frequently and additive (40.9%) or indifferent (36.3%) effect. When a synergistic effect was proved, it was always weak (FIC = 0.75). Combinations of two fluorinated quinolones with cefpirome gave similar results. No combination was antagonist. This study is a primary estimation of activity of cefpirome combined with other agents. It will be necessary to confirm these results against strains resistant with high level, especially against cefpirome, strains not discovered in clinical isolates at present.

4-Quinolones↗
PubMed1987

Diffusion of ofloxacin into human lung tissue.

Ofloxacin 200mg twice daily was administered to 17 patients with pulmonary disorders, which necessitated surgery, during the preceding 48 hours and 200mg was administered 1 hour before the operation. During surgery, blood samples and specimens of healthy and diseased lung tissues were taken simultaneously. Ofloxacin levels were determined by HPLC. The mean values of the tissue concentration/plasma concentration ratio were 3.5 +/- 0.4 for the healthy tissue and 3.9 +/- 0.4 for the diseased tissue. These values reflected good penetration of ofloxacin into both healthy and atelectasic pulmonary parenchyma.

Aged↗
PubMed1986

[Diffusion of ofloxacin in human lung tissue].

Ofloxacin was administered to 17 patients suffering from a pulmonary disorder necessitating surgery. The daily dosage employed was 200 mg b.i.d. during the 48 hours preceding the operation and 200 mg one hour before the operation. During surgery, blood samples and specimens of healthy and diseased lung tissue were taken simultaneously. The ofloxacin levels were determined by HPLC. The mean values of the tissue concentration/plasma concentration ratio were as follows: 3.5 +/- 0.4 for the healthy tissue and 3.9 +/- 0.4 for the diseased tissue. These values reflected good penetration of ofloxacin into both the healthy and atelectatic pulmonary parenchyma.

Anti-Infective Agents↗
PubMed1986

Study of the diffusion of cefmenoxime into the bronchial secretions.

The wide spectrum of antibacterial activity of cefmenoxime as well as its resistance to beta-lactamase degradation, confers upon this drug a probable efficacy in the treatment of common respiratory infections. The objective of this study was to evaluate the penetration of cefmenoxime into bronchial secretions taken in patients, mostly with chronically superinfected bronchial pathology. Bronchial samples were collected by means of fiber-optic bronchoscopy; simultaneous serum samples were also taken after bolus intravenous injection of 1 g of cefmenoxime, after a single dose in 12 patients (group I); after multiple doses in 12 patients (group II). Concentrations of cefmenoxime were determined by means of microbiological procedure. The results showed: bronchial kinetics of cefmenoxime similar to those of other cephalosporins studied previously; after multiple doses a bronchial steady state with a slow decrease of bronchial levels as a function of time; no difference between levels measured after single or multiple doses; a ratio between bronchial levels (B) and simultaneous serum (S) levels (B/S, %) of about 10% at the 2nd hour, 20% at the 4th hour. Due to the extremely low MICs for most bacteria responsible for respiratory infections, cefmenoxime might be expected as the drug of choice in the treatment of bronchopulmonary infections.

Bacterial Infections↗
PubMed1986

Antibacterial activity of roxithromycin: a laboratory evaluation.

Roxithromycin, formerly known as RU 28965 (9-[O [(2-methoxyethoxy)methyl]oxime]-erythromycin), is a novel 14 atom-membered semisynthetic macrolide with an antibacterial spectrum directed towards Gram-positive cocci and bacilli, Gram-negative cocci and some Parvobacteriaceae. The in vitro antibacterial activity of roxithromycin was compared with those of erythromycin and spiramycin against 275 clinical isolates by using 2-fold broth macro-dilution tests. The antibacterial spectrum of roxithromycin and erythromycin were qualitatively comparable (including the bacteriostatic type of activity and the profile of resistance), but minimal inhibitory concentrations of erythromycin were generally one half those of roxithromycin, except for Corynebacterium sp. and Bacteroides fragilis against which the new macrolide was more active. On the other hand, roxithromycin exhibited a superior in vivo antibacterial activity in laboratory animals, being up to six times more potent than erythromycin in curing experimentally infected mice. Roxithromycin showed high blood levels and long half-lives of elimination in rodents after oral administration, and its bioavailability amounted to 72% in mice and 85% in rats, compared to less than 10% for erythromycin. Roxithromycin was widely distributed throughout the body with a high degree of penetration into all tissues, particularly in the lungs.

Animals↗
PubMed1986

[In vitro activity of roxithromycin, new semisynthetic macrolide against obligate anaerobes].

The "in vitro" susceptibility to roxithromycin and three other macrolides of 236 anaerobes isolated from clinical samples in 1984/1985 was determined by an agar-dilution method on Wilkins Chalgren medium. 90% of Gram positive cocci were susceptible to both roxithromycin and josamycin (MIC less than 1 mg/l, whereas 1 mg/l erythromycin and 2 mg/l spiramycin were able to inhibit respectively 46 and 86% of the same tested strains. No resistance to the four macrolides was observed among Eubacterium, propionibacterium and Bifidobacterium. Two C. perfringens strains and one C. difficile strain were resistant to all four macrolides, while 97% of Clostridium sp. strains were inhibited by 4 mg/l erythromycin, josamycin or roxithromycin. Against Gram positive anaerobes, roxithromycin was equal or superior to erythromycin and spiramycin. At a concentration of 4 mg/l, roxithromycin inhibited 82% of B. fragilis strains. Roxithromycin and josamycin were more active against Gram negative bacilli that erythromycin and spiramycin. Macrolides had no effect on Fusobacterium strains. In this study, 4 mg/l roxithromycin inhibited 217 of the 236 anaerobic strains investigated (92%).

Bacteria, Anaerobic↗
PubMed1986

[In vitro antibacterial activity of a new cephalosporin: cefpirome (HR 810). Comparison with ceftriaxone, cefotaxime, latamoxef and ceftazidime].

In vitro activity of a new cephalosporin, cefpirome (HR 810) was tested using an agar dilution procedure against 393 hospital bacterial isolates. Results were compared to those obtained with ceftriaxone, cefotaxime, latamoxef and ceftazidime. Cefpirome was the most active drug against oxacillin-susceptible staphylococci and the only drug with activity against streptococci D (MIC 90%: 7 mg/l). Against Enterobacteriaceae strains with varying degrees of resistance to cephalosporins, results varied across species: activity of cefpirome was greater than that of the four other drugs for E. cloacae and C. freundii, similar to that of ceftriaxone for E. coli, S. marcescens, P. morganii and Salmonella sp., inferior to that of latamoxef for P. stuartii. However, against all Enterobacteriaceae strains as a whole, cefpirome proved the most active of the five agents tested (99.1% of strains inhibited by 4 mg/l) as a result of its greater activity against strains with resistance to second generation cephalosporins or cefotaxime. Cefpirome in a concentration of 4 mg/l inhibited 50% of tested P. aeruginosa strains (MIC 90%; 13 mg/l) and was inferior only to ceftazidime (MIC 90%: 4 mg/l). However, cefpirome exhibited no activity against A. calcoaceticus and L. monocytogenes.

Bacteria↗
PubMed1986

[Pharmacokinetics of ofloxacin in the elderly (65-85 years) with normal renal function after a single oral dose of 200 mg].

Ofloxacin is a fluoroquinolone that is mainly eliminated through the kidneys. We studied ofloxacin pharmacokinetics following administration of a single oral 200 mg dose to each of 16 elderly patients (77 +/- 2.4 years). Serum and urine concentrations were assayed using high performance liquid chromatography. Peak serum ofloxacin concentrations were 3.60 (+/- 0.36) micrograms/ml; residual concentrations were 1.33 (+/- 0.15) and 0.62 (+/- 0.10) micrograms/ml at 12 and 24 hours respectively. Urine concentrations approximating 100 micrograms/ml were found up to the 12th hour. As compared to healthy adults, in elderly subjects ofloxacin distribution volume (85.3 +/- 6.3 l) was decreased by 34%, apparent clearance (4.97 +/- 0.53 l/h) was divided by 2.6 and elimination half life (13.3 +/- 1.2 h) was almost doubled. A linear correlation was found between individual apparent ofloxacin clearances and creatinine clearances. In view of these significant changes in ofloxacin pharmacokinetics found in elderly subjects, we advocate reducing the usual dosage by half.

Administration, Oral↗
PubMed1986

[Pharmacokinetics of cefmenoxime in the aged subject (60 to 90 years of age) after an intravenous injection of 1 g].

A pharmacokinetic study of Cefmenoxime (CMX) has been carried out in 17 patients, 60 to 90 years old, following IV injection of 1 gram. Plasma concentrations of CMX were determined in 15 blood samples drawn between 0.25-12th hour by a specific high pressure liquid chromatography. The apparent terminal half lives calculated by regression analysis ranged from 0.94 to 3.8 h. We observed an increase of apparent elimination half life and a decrease of total clearance with aging as compared to that of healthy young subjects. Apparent volume of distribution seemed not to differ from those observed in young adults. There is a correlation between renal function and elimination kinetics of Cefmenoxime. In spite of kinetics modifications, it seems that it is not necessary to modify the dosage regimen in elderly.

Aged↗
PubMed1985

[Therapeutic prospects of new fluoroquinolones].

Fluoroquinolones are new synthetic derivatives with a broad spectrum and a potent antibacterial activity this permits to assimilate these molecules as antibiotics. These compounds are characterized by a quinoline or a naphthyridine nucleus with a fluorine atom in position 6 and a piperazine or a pyrrole nucleus in position 7. The combination of their antibacterial properties and the good absorption and tissue distribution allows their use in the treatment of the main infections caused by sensitive strains. The clinical and biological tolerance of these drugs are usually excellent.

Anti-Infective Agents↗
PubMed1985

Antibacterial activity of ofloxacin and other 4-quinolone derivatives: in-vitro and in-vivo comparison.

Ofloxacin (DL8280, RU43280) is a newly introduced oxazine quinolone derivative with broad and potent antibacterial activity. Ofloxacin showed excellent in-vitro activity against Enterobacteriaceae while most strains of Pseudomonas aeruginosa were inhibited by less than 2 mg/l. The compound was significantly more potent than norfloxacin against Acinetobacter spp. and Staphylococcus spp. Ofloxacin and norfloxacin behaved similarly with respect to inoculum size, effect of urine and serum, bactericidal properties and frequency of spontaneous resistant mutants. Ofloxacin displayed an in-vivo antibacterial activity up to five times greater than that of pefloxacin and norfloxacin, probably due to the conjunction of favourable pharmacokinetics, excellent bacterial susceptibility and good stability towards metabolic degradation.

Animals↗
PubMed1985

Placental transfer of cefmenoxime in late pregnancy.

The broad spectrum of activity and the beta-lactamase stability of cefmenoxime provide this new cephalosporin a possible efficacy in the treatment of obstetrical infections. This study was designed to evaluate the placental transfer of cefmenoxime. The study group consisted of 21 pregnant women undergoing a cesarian section. After a single intramuscular injection of 1 g of cefmenoxime, samples of maternal blood and amniotic fluid were taken 30 min before and at delivery; the same samples as well as umbilical cord blood samples were also taken 1, 2, 3 or 4 h after the injection, in order to evaluate the kinetics of the drug. The antibiotic assay was carried out by microbiological procedure. The results of the study showed (1) a peak level of 16 micrograms/ml in maternal serum, with a slow decrease and a residual value of 3 micrograms/ml at 4 h; (2) increasing levels of the drug in cord blood, with a peak value of 4.8 micrograms/ml; (3) a progressive diffusion of cefmenoxime in amniotic fluid, reaching the highest value of 4.7 micrograms/ml at 3 h, and (4) parallel kinetics of the drug in amniotic fluid and in cord blood. On the whole, this study showed a significant placental transfer of cefmenoxime, achieving therapeutic concentrations required against microorganisms responsible for obstetrical infections.

Amniotic Fluid↗