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Biomedical subjects

B Grenier

Publications and source records attributed to B Grenier.

At least 19 recordsLinked to original sources
PubMed1991

Suction blisters technique in amikacin diffusion through interstitial fluid in cystic fibrosis.

Modifications in the pharmacokinetics of aminoglycosides have been reported among patients with cystic fibrosis. We obtained suction blister fluid (SBF) to study the tissue diffusion of amikacin in cystic fibrosis in 2 children (a 9-year-old boy and a 7-year-old girl) over the course of bronchopulmonary infection. Amikacin was administered intravenously using a single dose of 5 mg/kg. The peak plasma concentrations were 24.5 and 11.2 mg/l, and the peak SBF concentrations were 8.3 and 3.2 mg/l. The ratio of the area under the curve in SBF and plasma was 58 and 60%, respectively. These results suggest a good penetration of amikacin through SBF and a good tissue diffusion of amikacin. The preliminary data suggest that the suction blister method may be useful to assess the tissue diffusion of drugs.

Amikacin↗
PubMed1991

[Tools for the evaluation of diagnostic techniques].

This presentation focuses on evaluation of the diagnostic value of clinical findings, laboratory test results and data provided by diagnostic technologies including imaging techniques. A sign S or indicant of a disease D is a datum which is more frequent (more likely) in patients with the disease D than in subjects free of the disease D. The ratio of these two conditional probabilities is the likelihood ratio or Bayes factor of S for D. For a given test T, the number of likelihood ratios is equal to the number of different result patterns obtained with test T. The likelihood ratio reflects the role of the test result in the predictive value, i.e., the likelihood that the disease is present given the test result observed. The likelihood ratio is the tool of choice for evaluating the diagnostic value of a test. The method proposed by Spiegelhalter and Knill-Jones is based on the likelihood ratio. Evaluation of an imaging technique rests on the characteristics of the "image-physician" combination. The rating method can be used to analyze Receiver Operating Characteristic curves in view of assessing either the imaging technique or the physician's diagnostic skills.

Clinical Laboratory Techniques↗
PubMed1990

[Choice of antibiotic treatment in otitis media].

The choice of antibiotics to be prescribed in otitis media may be guided by microbiological culture of the middle ear exudate obtained by tympanocentesis, or by direct examination and culture of purulent material obtained by myringotomy after rupture of the tympanic membrane. Otherwise, routine antibiotic prescription is based on the epidemiological frequencies of bacteria such as Streptococcus pneumoniae, Hoemophilus influenza or Strepcococcus A. In children who have infrequently received beta-lactam antibiotics, amoxicillin 50-75 mg/kg/day for 10 days may be the first choice. Children who suffer from recurrent episodes of acute otitis media may benefit from one of the three following prescriptions: amoxicillin + clavulanate (Augmentin), or an oral cephalosporin, or the erythromycin + sulfisoxazole combination (Pediazole). If recurrences are frequent and at short intervals, antibiotic prophylaxis may be effective, using penicillin V (Oracillin) 250,000 IU daily throughout the entire cold period.

Acute Disease↗
PubMed1990

[Is the qualitative research of benzodiazepines by the EMIT method and diazocopulation in accidental poisoning in children relevant?].

A retrospective study was undertaken to evaluate the relevance of benzodiazepine detection in 42 children with accidental poisoning. Immunoenzymatic assay for benzodiazepine in serum and colorimetric method in urines were positive respectively in 3 and 4 patients only. Several reasons could explain these results: the high detection threshold, the different drug reactivity according to the molecular structure and the great delay between intoxication and toxicology analysis. An advised physician should not prescribe a toxicological analysis after a small quantity of benzodiazepine ingestion.

Benzodiazepines↗
PubMed1988

Distribution of cholesterol in milk fat fractions.

Milk fat was fractionated into liquid (m.p. congruent to 12 degrees C), intermediate (m.p. congruent to 21 degrees C) and solid (m.p. congruent to 39 degrees C) fractions by three different processes--melt crystallization, short-path distillation and supercritical CO2 extraction--and the cholesterol content of these fractions determined. Cholesterol was enriched in the liquid fractions from all three processes, in particular about 80% of the cholesterol being found in the liquid fraction obtained by short-path distillation. The basis of migration of cholesterol into various milk fat fractions was explained by its affinity to various triglycerides (melt crystallization) and by vapour pressure and molecular weight (short-path distillation). It was more complex in the supercritical CO2 extraction process; the interplay of cholesterol affinity toward CO2 and its molar volume, and its vapour pressure enhancement under applied pressure play a role.

Animals↗
PubMed1987

[Erythromelalgia, arterial hypertension and increased excretion of urinary catecholamines].

A 7 year-old girl was hospitalized with acute, severe and drug resistant erythromelalgia. During her stay in the hospital, she presented with an epileptic seizure associated with hypertension (220-120 mmHg). Catecholamine urinary excretion was markedly increased. Diagnoses of pheochromocytoma and acrodynia were excluded. Erythromelalgia and hypertension both disappeared in a few days without any relapse after a 2 year-follow-up. Catecholamine urinary excretion returned to normal levels in a few weeks. A skin biopsy which was performed in an affected site, showed a slight and questionable reduction of the density of autonomic adrenergic nerve terminals in the periarterial and glandular plexuses. The relevance of transitory excess catecholamine excretion and its link with erythromelalgia and hypertension are discussed. The hypothesis that the disorder could be explained by an abnormality of distal autonomic axons is likely.

Catecholamines↗
PubMed1986

Pharmacokinetics of amikacin in cystic fibrosis: a study of bronchial diffusion.

36 pharmacokinetic studies of amikacin were performed to evaluate the bronchial diffusion of amikacin in 9 children with cystic fibrosis, 3 to 15 years old. Amikacin was administered i.v. according to a variable dosage regimen. Four children without cystic fibrosis were enrolled as controls. The mean half life was 1.1, the volume of distribution averaged 0.26 l/kg, and the mean plasma clearance was 131 ml/min/1.73 m2, which no differed from that of the controls. The mean peak plasma concentration was always above the MIC but its level depended on the unit dose: 18.5 mg/l, 25,95 mg/l and 31,46 mg/l for doses of 5, 7.5 and 12.5 mg/kg, respectively. Between consecutive amikacin infusions, the plasma level was above the MIC for 21% and 46% of the time after the 5 and 7.5 mg/kg doses. The maximum concentration in sputum between H1 and H2 was always below the MIC, except after 15 mg/kg. The ratio AUC sputum/AUC plasma was between 0.028 and 0.61, and it increased from the beginning to the end of the course of treatment. No side effects were observed on hearing, or vestibular and renal function. The results are used to suggest more appropriate dosing regimens.

Adolescent↗
PubMed1985

Pertussis immunization of infants using a new combined DTP-polio vaccine.

As part of the evaluation of a new combined Diphtheria-Tetanus-Pertussis-Poliomyelitis (DTP-Polio) inactivated vaccine, the pertussis agglutinin response was studied in 62 infants, two to three months old. Each dose of vaccine combined these antigens in a 0.5 ml volume, and contained at least four International Protective Units of pertussis antigen adsorbed on aluminium hydroxide. Infants were vaccinated with three doses of DTP-Polio vaccine at two month intervals. Pertussis agglutinin determinations showed a satisfactory response after two DTP-Polio vaccine doses. Although higher agglutinin titres were apparent after three doses than after two, no significant difference was observed in the seroconversion rate after two or three doses (88.8% and 96.3% respectively). The DTP-Polio vaccine would thus seem suitable for use in a two-dose primary immunization schedule against pertussis.

Agglutinins↗
PubMed1985

Rotavirus electrophoretypes in infantile gastro-enteritis. An epidemiological study.

From January first 1978 to September 30, 1981, 93 fecal samples from children hospitalized with a rotavirus gastro-enteritis were tested after RNA extraction and polyacrylamide gel electrophoresis. 14 electrophoretypes (TI--T14) were identified by this technique. They were studied in relation with epidemiological as well as clinical symptoms. No electrophoretype correlated well with age or living area. The electrophoretype T3 was found only in male infants and the electrophoretype T7 was 3 times more frequent in boys than in girls. The electrophoretype T4 was prevailing during the winter 1980-1981 and the electrophoretype T5 prevailed during the summer 1981. 19 infants were probably contaminated during their stay in the hospital, 9 of them with the electrophoretype T4 prevailing at that time. The prevalence of associated otitis and rash was significantly higher with the electrophoretype T3. The polyacrylamide gel electrophoresis technique appears to be a simple, and reliable epidemiological tool to evaluate rotavirus infection in communities.

Child, Preschool↗
PubMed1985

[Ceftazidime absorption into bronchial secretions in mucoviscidosis patients].

Penetration of ceftazidime into bronchial secretions was studied in 23 patients, of which 18 had cystic fibrosis. Ceftazidime was used as the single drug for treating exacerbations caused by Pseudomonas aeruginosa. Dosage was 6 g/1.73 m2/day divided into three intravenous injections for 14 to 21 days. Bronchial secretion samples were obtained by fiber-optic bronchoscopy or physical therapy. Serum and bronchial secretion ceftazidime concentrations were assayed using a microbiological method. Ceftazidime concentrations in both media were lower in children than in adults : elimination half-life is shorter (1.7 h against 2.45 h in adults), extravascular distribution is faster, with earlier (1 h against 2 h in adults) achievement of the peak bronchial secretion concentration (2 micrograms/ml). The ratio of bronchial secretion concentration to concomitant serum concentration did not exceed 5% at the time of peak bronchial concentration. These results suggest that in cystic fibrosis patients, the faster and lower bronchial penetration of ceftazidime may be due to faster elimination as compared to adults. Although transient elimination of Pseudomonas aeruginosa was achieved in 12 study patients, our findings support the use of higher dosages or alternative administration modalities designed to increase in situ ceftazidime concentrations.

Adolescent↗
PubMed1985

[True and false agreement relations between 2 qualitative tests].

The respective effectiveness of two qualitative tests is usually compared by their results when applied to a same specimen or subject. The results reported in a fourfold table show coincident numbers of double positive and double negative results. That straight concordance is fallacious, including the chance coincidences. Test Kappa measures the true agreement, without the chance coincidences. Kappa value may be compared to a maximum value of agreement depending on the marginal results of the fourfold table. As a matter of fact, the test Kappa is a non parametric correlation function comparable to the non parametric correlation coefficient Phi computed from the value of the chi square test.

Clinical Laboratory Techniques↗