Biomedical subjects

H Monteil

Publications and source records attributed to H Monteil.

At least 163 records · Page 9Linked to original sources

PubMed1987

Biliary elimination of ceftazidime.

When five normal subjects were given ceftazidime 2 g iv, antibiotic concentrations in aspirated duodenal fluid increased progressively during 4 h to a value of 21.2 +/- 9.2 mg/l (mean +/- S.E.M.); 0.05% of the dose given was recovered in duodenal fluid. The same dose was given to 12 patients with an external biliary drain. The mean peak ceftazidime concentration of 36.3 +/- 4.0 mg/l was reached in the collected bile during the second hour after administration. The 12-h biliary recovery was 0.21% of the dose. The respective ceftazidime concentrations in choledochal and gallbladder bile sampled peroperatively in ten patients 1 h after ceftazidime 2 g iv were 78.3 +/- 12.0 and 17.9 +/- 7.5 mg/l. These data compare favourably with the results achieved with other beta-lactam compounds.

Adult↗

PubMed1987

Classification and identification of Flavobacterium species by carbon source utilization.

Carbon substrates used as the sole source of carbon and energy were tested for the classification and identification of species of Flavobacterium: Flavobacterium meningosepticum, F. breve, F. odoratum, F. multivorum, F. thalpophilum, and Flavobacterium sp. group IIb. Hierarchical classification and stepwise discriminant analysis revealed three F. meningosepticum, two F. breve, two F. odoratum, and two Flavobacterium sp. group IIb subgroups. Glucose, histidine, asparagine, tryptophan, maltose, citric acid, and glycine were selected as the most useful substrates to differentiate between the groups and subgroups.

Alcohols↗

PubMed1987

[Experimental evaluation of the biliary tract passage of ceftriaxone and its hepatic disposition].

The biliary elimination of ceftriaxone was studied by an isolated perfused rabbit liver model (n = 5). After adding of 10 mg of this antibiotic to the circulating blood of this preparation, a mean biliary peak level reaching 120.5 +/- 24.6 micrograms/ml was obtained between the 30th and 60th minutes. The total amount of ceftriaxone eliminated unchanged in the bile collected during a 3h period represents 8.8 +/- 2.6% of the administered dose. At the end of this study period, 32.7 +/- 3.3% of the initial dose remained in the circulating blood. The hepatic tissue concentrated 3.7% of the whole dose. At last, control experiments proved that 36.4% of the added antibiotic has been degraded by the experimental system itself. Thus the remaining 18.4% can be attributed to a hepatic biotransformation of ceftriaxone.

Animals↗

PubMed1987

[Direct determination of clavulanic acid in biological fluids using HPLC].

The so far described HPLC methods for clavulanic acid (CA) monitoring needed post-column derivatization with imidazole, resulting in poorly practicable methods. We propose here a direct determination of CA in human biological fluids with a ion-pairing technology using the bathochromic shift of tetrabutylammonium bromide (TBAB). The separation is performed on a reversed phase analytical column (250 X 4.6 mm) with the following mobile phase: 10% acetonitrile in 1 mM TAB and 20 mM ammonium acetate (pH = 5). The U.V. detection is at 214 nm. Serum and bile are prepared with acetonitrile and methylene chloride, and urines are diluted 1/10 prior the analysis. Retention time of CA is 8.4 min. Detection limit for bile and serum is 0.1 mg/l and 5 mg/l for urines. Within and between-day reproducibility is respectively 5.4% and 7.2% for serum and bile, and 4.7% and 6.8% for urine. This method may be suitable for clinical routine analysis and pharmacokinetic studies.

Bile↗

PubMed1987

[Comparative activity of ticarcillin-clavulanic acid and various beta-lactams against Pseudomonas maltophilia].

An increase is observed in the isolation of P. maltophilia as a casual agent of nosocomial infection, particularly in hospitalized immunocompromised patients. These infections are associated with the acute problem of their treatment as most of the P. maltophilia strains are generally resistant to many of the commonly used antimicrobial agents, including those active against Pseudomonas aeruginosa: beta lactams, aminoglycosides and imipenem. This resistance is correlated with two inducible beta lactamases (L1, pI = 6.9; L2, pI = 8.4). Azlocillin, piperacillin, cefoperazone, ceftazidime, latamoxef, ticarcillin, ticarcillin and clavulanic acid in combination were tested against 93 P. maltophilia isolates by disk diffusion testing and agar dilution technique. The association of clavulanic acid with ticarcillin resulted in better MIC values for ticarcillin (MIC 50 = 32, MIC 90 = 128). 96% of strains were sensible to the breakpoint of 128 mg/l. Other beta lactam antibiotics showed a loss of activity except for latamoxef (67% of strains susceptible to 4 mg/l) which is a potent inhibitor of both beta-lactamases. According to these results, the combination of clavulanic acid with ticarcillin may be useful in the treatment of P. maltophilia acquired hospital infections.

Anti-Bacterial Agents↗

PubMed1987

Ceftazidime: experimental and clinical evaluation of biliary elimination.

During a 3-h perfusion of five isolated rabbit liver preparations, 1.4% of 10 mg of ceftazidime added to the circulating blood was eliminated in the bile and 0.9% was metabolized or inactivated in the liver. Five normal subjects were given 2 g of ceftazidime intravenously; antibiotic concentration in the aspirated duodenal fluid rose progressively during the 4 h of the investigational period to a maximal mean level of 21.3 +/- s.e.m. 9.2 micrograms/ml and 0.05% of the dose given was recovered during this period. The same dose was given to 12 cholecystectomized patients fitted with a Kehr drain. An average peak value of 36.3 +/- 4.0 micrograms/ml was reached in the collected bile during the second hour after drug administration. The 12-h biliary recovery was 0.21% of the dose given. Ceftazidime concentrations in choledochal and gallbladder bile sampled peroperatively in 10 patients 1 h after intravenous administration of 2 g of ceftazidime were 78.3 +/- 12.0 and 17.9 +/- 7.5 micrograms/ml respectively. These data compare favourably with the results of the authors' studies on the biliary elimination of 15 other beta-lactams and are consistent with a possible beneficial effect of ceftazidime in the treatment of biliary tract infections.

Adult↗

PubMed1987

[Meningoradiculitis after a tick bite. Study of 31 cases].

A retrospective study covering a period of 20 years identified reports on 31 cases of meningoradiculitis of the Garin-Bujadoux-Bannwarth type (MRGBB). Clinical, biological, electromyographic characteristics and course of the disease were studied. The most recent cases (n = 8) in 1984 and 1985 had serological tests for Borrelia Burgdorferi and half of the cases had negative results. Conversely, in some patients with meningoradiculitis, even in the absence of a tick bite or of migrating chronic erythema, serology was positive for Borrelia Burgdorferi antigen. The efficacy of antibiotic therapy against pain and on the quality and time of functional recovery justifies the use of this therapy under these two circumstances.

Bites and Stings↗

PubMed1986

[Evaluation of bile diffusion of piperacillin].

In 10 patients undergoing cholecystectomy peroperative samples of serum, bile and gall bladder tissue were obtained one hour after intravenous injection of 2 g of piperacillin. Measurements were made by high performance liquid chromatography. Mean concentrations of piperacillin were 81.7 +/- 13.6 micrograms/ml in serum (S), 382 +/- 110 micrograms/ml in choledochal bile (CB), 30.8 +/- 8.5 micrograms/ml in gall bladder bile and 10.5 +/- 2.6 micrograms/g of gall bladder tissue. With a CB/S ratio of 4.7, piperacillin may be classified among beta-lactams showing good distribution in the biliary tract. This property would make piperacillin useful against the pathogens usually responsible for biliary tract infections.

Adult↗

PubMed1986

Characterization of Flavobacterium species by analysis of volatile fatty acid production.

Seventy-four Flavobacterium strains were characterized by gas-liquid chromatographic analysis of volatile fatty acids produced in the culture medium. Principal components analysis permitted the graphic representation of the relative positions of the different strains, and aggregation according to the variance enabled a hierarchical classification to be established. The study revealed three subgroups each for F. meningosepticum and F. odoratum. Our F. breve, Flavobacterium sp. group IIb and F. multivorum strains appeared to be homogeneous. These results tallied with those of previous studies on DNA base composition and reassociation, electrophoretic protein profiles and cellular fatty acid composition.

Butyrates↗

PubMed1986

[Experimental and clinical evaluation of the biliary elimination of ceftazidime].

After adding 10 mg of ceftazidime to the circulating blood of five isolated rabbit liver perfusions, total antibiotic excretion over a 3 hours period accounted for 1.4% of the administered dose; only 0.9% was found to be metabolized by the liver. In five healthy subjects given 2 g ceftazidime intravenously, 0.05% (102 +/- 576 micrograms) was recovered in the duodenal fluid over a four-hour period. In 10 patients with a T-tube inserted following cholecystectomy, 0.21% of a 2 g dose of ceftazidime injected intravenously was found in the bile collected over a 12-hour period (4 161 +/- 489 micrograms); a mean biliary peak of 36.3 +/- 4.0 micrograms/ml was recorded during the second hour. In 10 patients in whom serum, choledochal bile and gallbladder bile were sampled simultaneously during surgery 1 hour after IV administration of ceftazidime, the concentrations found were 40.6/e 2.1, 78.3 +/- 12.0 and 17.9 +/- 7.5 micrograms/ml respectively. Our results suggests that ceftazidime may be suitable in the treatment of biliary tract infections.

Adult↗

PubMed1986

[Evaluation of the sensitivity to antibiotics of Bacteroides and Fusobacterium using the ATB ANA system].

The susceptibility to antibiotics of 100 Gram negative obligate anaerobes of the Bacteroides and Fusobacterium species was tested using the ATB ANA method. Results were compared to those obtained by addition of the tested antibiotics to Wilkins-Chalgren medium in the critical concentrations. Agreement between the two methods was satisfactory (80 to 100%) for the low cutoff concentrations, except for doxycycline. When the pathogens are divided into susceptible, intermediate and resistant strains, results are more difficult to interpret because of the existence of the intermediate category: however, major discrepancies (R/S) did not exceed 3.2% except for cefotaxime (15%). Our results show that use of ATB ANA microplates in an anaerobic enclosure is a valuable method in clinical practice.

Anti-Bacterial Agents↗

PubMed1985

High-performance liquid chromatographic method for determination of ciprofloxacin in biological fluids.

A simple and precise high-performance liquid chromatographic procedure has been developed for the determination in biological fluids of ciprofloxacin, a new, with extended antibacterial spectrum, quinoline carboxylic acid. The work-up procedure involves a chemical extraction step followed by isocratic chromatography on a reversed-phase analytical column, with ultraviolet detection. The detection limit for blood levels is 10 ng/ml. The calibration curve is linear from this detection limit to 10 microgram/ml. The statistical analysis of the correlation made between this assay and an agar diffusion procedure during a pharmacokinetic study suggests the existence of one or more active metabolites which could be mainly excreted in the bile.

Anti-Infective Agents↗

PubMed1985

[Ciprofloxacine: evaluation of its biliary elimination in man].

To investigate the possibility of therapeutic use of ciprofloxacin in infections of the biliary tract, the serum and bile kinetics, and the biliary, urinary and fecal elimination of this new broad-spectrum quinolone were studied in 12 recently cholecystectomized patients with T-tube drainage. Ciprofloxacin concentrations were determined by simultaneously performed HPLC and microbiological assay in serum, urine, and bile over a 24-hour period following oral administration of a single dose of 500 mg of the drug. The two methods yielded similar values both in the serum and in the urine. Average peak serum concentrations were 0.97 +/- SEM 0.17 microgram/ml (HPLC) and 1.08 +/- 0.19 microgram/ml (microbiological assay) (NS). The respective mean urinary concentrations in the first 6-hour sample were 267 +/- 74 micrograms/ml and 241 +/- 58 micrograms/ml (NS). In bile, however, the microbiological assay gave higher values than HPLC:average peak concentrations of 10.3 +/- 3.4 micrograms/ml and 7.5 +/- 2.8 micrograms/ml (p less than 0.02) respectively, reached during the 2nd hour after drug administration, and mean total 24-hour biliary ciprofloxacin output of 2167 +/- 288 micrograms and 1587 +/- 222 micrograms (p less than 0.01) respectively. This may point to hepatic transformation of ciprofloxacin to more active metabolite(s) than the parent compound. The significantly higher concentrations of ciprofloxacin in bile than in serum exceeded the minimum inhibitory concentration for organisms usually responsible for biliary infections. These infections may, therefore, be favorably affected by ciprofloxacin.

Adult↗

PubMed1985

Effect of the cytotoxin of Clostridium difficile on cultured hepatoma cells.

Clostridium difficile is the major etiologic agent of human pseudomembranous colitis. It produces two toxins: an enterotoxin and a cytotoxin. In cultured hepatoma cells, at very low doses, the cytotoxin inhibits the incorporation of precursors into biological macromolecules. Protein synthesis is more affected than RNA and DNA synthesis. The toxin also induces severe alterations of the cell morphology consisting in damages to the cytoskeleton and to the cell shape.

Animals↗

PubMed1985

Determination of vancomycin in human serum by high-pressure liquid chromatography.

A rapid, accurate, reverse-phase high-pressure liquid chromatographic procedure for vancomycin quantitation in human serum, cerebrospinal fluid, and peritoneal fluid was developed. This procedure involves a simple chemical extraction of the antibiotic and is suitable for each of these body fluids. The column and mobile phase used provided a good resolution of the vancomycin peak with a retention time of 6.1 min. The precision of the assay was within the requirement for a daily routine clinical application. Coefficients of variation for within-day reproducibility were 5.80 and 6.28%, respectively, for samples at 50 and 25 micrograms/ml, and for between-day reproducibility they were 11.4 and 11.1%, respectively. No interference was found with respect to beta-lactam and aminoglycoside antibiotics and many other currently used drugs, indicating a good specificity for the procedure. The detection limit of 100 ng/ml has proven to be sufficient for monitoring drug levels in serum obtained after usual dosages. Drug levels in 112 clinical serum specimens assayed by high-pressure liquid chromatography were regressed against the levels obtained for the same samples by radioimmunoassay and fluorescent polarization immunoassay. Correlation coefficients were 0.945 and 0.967, respectively, and were highly significant (alpha less than 0.001).

Bacterial Infections↗

PubMed1985

Comparison of high-pressure liquid chromatography and microbiological assay for the determination of biliary elimination of ciprofloxacin in humans.

Serum kinetics and biliary, urinary, and fecal elimination of ciprofloxacin, a new quinolone derivative, were studied in 12 recently cholecystectomized patients provided with T-tube drainage during 24 h after oral administration of a single 500-mg dose of this substance. Drug concentrations were measured by both high-pressure liquid chromatography (HPLC) and microbiological assay. The results were comparable for the concentrations in serum (average of peaks, 2.0 +/- 0.2 micrograms/ml by HPLC and 2.3 +/- 0.3 micrograms/ml by the microbiological method) and urine (0 to 6 h, 267 +/- 74 and 241 +/- 58 micrograms/ml, respectively). This was not the case for biliary values, for which the microbiological assay yielded significantly higher concentrations than did HPLC (average of peak concentrations, 21.2 +/- 2.6 and 16.0 +/- 2.5 micrograms/ml, respectively [P less than 0.02]), nor for total 24-h biliary output (2,167 +/- 288 and 1,587 +/- 222 micrograms, respectively [P less than 0.01]). This suggests hepatic biotransformation of ciprofloxacin into microbiologically active metabolites. The apparent broad antibacterial spectrum of ciprofloxacin and its higher biliary levels than simultaneously determined serum concentrations suggest that this derivative is suitable for the treatment of biliary tract infections.

Adult↗

PubMed1985

[HPLC, RIA, FPIA. Evaluation of 3 methods for the assay of vancomycin].

We describe a rapid and accurate high performance liquid chromatographic (HPLC) method for vancomycin quantitation. This method is then compared with two immunoassays, RIA and FPIA. The chemical extraction step needed for HPLC is simple and rapid. Both conventional reversed phase HPLC and high speed reversed phase HPLC were tested. The mobile phase was a mixture of aqueous ammonium acetate and acetonitrile. Specificity of the HPLC assay was good. Serum levels in 112 clinical specimens assayed by HPLC were regressed against the levels obtained for the same samples by both RIA and FPIA. The correlation was good (RIA : r = 0.945; FPIA : r = 0.967). Considering the disadvantages of RIA, HPLC and FPIA emerge as the methods of choice.

Chromatography, High Pressure Liquid↗

PubMed1985

[Isolation of Aeromonas hydrophila in diarrhea. Characterization of enterotoxinogenic strains and clinical relations].

Aeromonas hydrophila is isolated from diarrhoea specimens with increasing frequency. The interest in this organism at the present time is related to the fact that it can produce a number of toxins, in particular alpha and beta cytotoxic haemolysins, an enterotoxin and various enzymes. The authors determined the frequency of isolation of this organism and tested the haemolytic, cytotoxic and enterotoxic effects of culture filtrates in all of the stool specimens received in their laboratory over a period of 9 months. At the same time, the clinical context was defined in order to demonstrate a relation between the aptitude of the strains to produce toxins and the presence of diarrhoea. The frequency of isolation of A. hydrophila was 0.88 per cent, which corresponds to 67 strains. 38 strains presented a haemolytic and/or enterotoxic activity, i.e. 57 per cent of the strains isolated. In diarrhoeal stools, 67 per cent of the A. hydrophila isolated produced at least one of the toxins, while in the group of patients without diarrhoea, only 38 per cent of the strains isolated produced toxins. The results obtained reveal a statistically significant correlation between the production of cytotoxic haemolysin and the presence of diarrhoea. In contrast, there was no correlation between the production of enterotoxin and the presence of diarrhoea. Twenty of the 67 strains ware isolated from children under the age of 2 years. In 40 per cent of cases, no other aetiology could be found for the diarrhoea, apart from the isolation of A. hydrophila.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗