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Biomedical subjects

G Lagier

Publications and source records attributed to G Lagier.

At least 19 recordsLinked to original sources
PubMed1991

Effects of some chelating agents on bismuth absorption in the rat.

Bismuth encephalopathies appeared in the mid-seventies in France and concerned about 1,000 people and led to a fatal outcome in 70 cases. Responsibility of Bi was clearly confirmed by the disappearance of the intoxication after prescription of drugs containing Bi had been more tightly regulated. Since the implication of a substance increasing the intestinal absorption of Bi has been suspected, we studied the concentrations of Bi in the tissues of rats who had been treated with bismuth nitrate basic 400 mg/kg per d for one month with and without an intake of a chelating agent added to the drinking water at a concentration of 10 mmol/l. The chelating agents tested were ethylenediaminetetraacetic acid (EDTA), nitriloacetic acid (NTA) and tripolyphosphate (TPP), cysteine and diethyldithiocarbamate (DEDTC). Cysteine and DEDTC gave the highest increase of Bi in tissues but with a wide dispersion of levels. However, even in the rats with the highest levels of Bi, there were no behavioral problems. EDTA induced an increase of Bi in kidney, brain and bone and NTA in kidney but there was no obvious sign of toxicity. We did not succeed in reproducing in rats the Bi toxicity observed in patients some years ago.

Animals↗
PubMed1991

Steady-state population pharmacokinetics of sustained release theophylline in adult asthmatic patients.

The steady-state population pharmacokinetics of theophylline were studied in 52 asthmatic adult patients who received sustained-release theophylline as armophylline or euphylline. A total of 92 steady-state plasma theophylline concentration-dosage pairs were analyzed using a nonlinear mixed effects model. The pharmacokinetic model used was a one-compartment open model with single path Michaelis-Menten elimination. Dosage was adjusted to body weight. The effects of age, gender, alcohol consumption, cigarette smoking, dosage form, concurrent treatment with beta-agonists or steroids, outpatient dosing, and plasma caffeine concentration on maximum elimination rate (Vm) and Michaelis constant for theophylline metabolism (Km) were investigated. Hypothesis testing produced a final model in which Km = 0.42 (mg/l), and Vm (mg/kg per day) was based on cigarette smoking and dosage form, with Vm = 7.54 + 2.01 (smoking) + 1.08 (euphylline). Estimated coefficients of variation for interindividual variability in Km and Vm were 162.6% and 48.1%, respectively. Residual variability in dosage rates was estimated as 0.90 mg/kg per day. The identification of factors influencing theophylline disposition should prove useful for the a priori design of theophylline dosage regimens and monitoring of drug levels during therapy.

Adult↗
PubMed1989

[Drug-induced renal insufficiency. Results of consensus meetings].

We report the conclusions of consensus meetings organized by the "Direction de la Pharmacovigilance" of Roussel Uclaf, and attended by University Hospital Nephrologists, members of the National Network of Pharmacovigilance and representatives of Roussel Uclaf Drug Monitoring Department, in order to define more accurately, as regards drug-induced renal failure, the criteria and the terminology proposed by the French method of causality assessment of adverse drug reactions.

Humans↗
PubMed1988

[Presence of benzodiazepines in the serum of patients after accidents. Relation to alcoholism].

In a study of 2.021 injured persons (accidents at home or at work, road accidents), qualitative assays of serum benzodiazepines by the EMIT method were positive in 9.6 per cent of the cases, including 3.2 per cent who had blood alcohol levels in excess of 0.10 g/l. Benzodiazepines were more frequently found in accidents at home and on roads than in accidents at work. These results raise the question of the role played by benzodiazepines as a possible risk factor of accidents, notably road accidents.

Accidents↗
PubMed1988

Detection of blood benzodiazepines in injured people. Relationship with alcoholism.

In 2021 accident victims (household, work and road accidents) the qualitative test for benzodiazepines in the serum by the EMIT method was positive in 9.6% of cases, including 3.2% of subjects who also had a blood alcohol level greater than 0.10 milligram. Benzodiazepines were detected with a particularly high frequency in household accidents and road accidents and rarely in work accidents. These results raise the problem of the role of benzodiazepines as a possible risk factor for accidents, particularly road accidents.

Accidents↗
PubMed1987

Quantitative modifications of major histocompatibility complex (MHC) antigens induced by recombinant gamma interferon in two human breast cancer lines.

H466-B and T47-D breast carcinoma cell lines were treated with recombinant gamma interferon (r gamma IFN) to study major histocompatibility complex (MHC) class I and class II antigen responses. Untreated H466-B cells released B2 microglobulin (B2M) into the culture medium and expressed B2M and class I heavy chain on 100% of the cells. The expression of class II antigens (DR) was limited to 8 +/- 4% of the cells. This subpopulation was isolated by cell sorting and labelled with 35S methionine. Protein extracts were immunoprecipitated with anti-DR antibody and subjected to two dimensional non-equilibrium pH gradient electrophoresis (2D-PAGE). A normal pattern of expression of invariant, alpha and beta chains was shown. The MHC antigenic expression of H466-B parental cell line was not modified by interferon treatment. Untreated T47-D cells did not release B2M into the culture medium, expressed B2M and class I heavy chain on 100% of the cells but did not express class II molecules using radio-immunoassay or 2D-PAGE. As early as 24 h after r gamma IFN addition, T47-D cells released B2M into the medium, B2M and class I heavy chain were significantly greater than that of untreated cells, and class II antigenic expression was found, all these in a dose dependent manner. 2D-PAGE analysis of class II antigens revealed the profile of human DR molecules but this expression seemed incomplete since only single alpha and beta spots were detected suggesting a possible defect in the sialilation of DR molecules. These results show a heterogeneity in MHC antigenic responses to r gamma IFN and suggest that synthetized class II molecules may be incompletely processed.

Antibodies, Monoclonal↗
PubMed1987

1,25-Dihydroxycholecalciferol induces an increase in PGE1- and forskolin-stimulated cyclic-AMP production in T47D human breast cancer cell line.

The effect of 1,25-dihydroxycholecalciferol [1,25(OH)2D3], the active form of vitamin D3, on cell growth, clonogenicity, and cyclic adenosine monophosphate (cAMP) production was examined in human breast cancer cell line T47D. 1,25(OH)2D3 markedly inhibited proliferation of T47D cells in a time- and concentration-dependent manner. 1,25(OH)2D3 5 X 10(-7) reduced to 70% [3H]thymidine incorporation into DNA. Specific high affinity nuclear receptors for 1,25(OH)2D3 were present in this cell line. The cAMP produced by T47D cells was measured during 10 min stimulation by effectors (prostaglandin E1 or forskolin). Without effector, T47D cells produced similar amounts of cAMP in control and 1,25(OH)2D3-treated cells. After 3 days in the presence of 1,25(OH)2D3, cAMP production was significantly increased compared to control cells when stimulated by 10(-4) M prostaglandin E1 or 5 X 10(-7) M forskolin (3.2- and 2.4-fold increase, respectively). This cAMP increase was concentration dependent within the same range that inhibited cell growth and clonogenicity. These results suggest that 1,25(OH)2D3 may indirectly affect cAMP production by modulating the target cell response to stimulatory agents of cAMP production.

Alprostadil↗
PubMed1987

[Criteria for assessing granulocytic or platelet cytopenia caused by drugs. Results of consensus meetings].

The use of an official drug adverse reaction assessment procedure became compulsory in France in 1984. The method proposed various qualifications for the semiologic and chronologic criteria used to ascribe a disorder to a specific drug but did not define them. Consensus meetings have been organized in order to define, in the main pathological fields, the adverse reactions themselves and the various qualifications of the criteria. This paper reports the results of meetings attended by hematologists, members of the French national network of Pharmacovigilance and representatives of Roussel Uclaf Drug Monitoring Department for drug-induced granulocyte and platelet cytopenias. Participants studied (a) the limits of the time interval between the appearance of the adverse reaction and the beginning or the end of the treatment with the suspected drug; (b) interpretation of a possible rechallenge; and (c) diagnostic value of in vitro tests proposed to confirm the responsibility of a specific drug in a granulocytic or platelet cytopenia.

Agranulocytosis↗
PubMed1986

[Detection of drug-induced nephrotoxicity].

This is a report of a round table organized during the second meeting of Clinical Pharmacology held in Giens (France) in September 1985. At the beginning of the meeting, the clinical aspects of drug-induced nephrotoxicity were reviewed. Thus we tried to precise the real interest of the studies of proteinuria, urinary cytology, enzymuria and fractional clearances of lithium or magnesium. The most interesting part of our discussions was to know the point of view of men working in drugs companies when a renal abnormality is found during a clinical trial of a drug and when previous experimental studies did not find any renal adverse effects of the drug. It was suggested in a such situation to do particular studies. Methods generally used to study renal physiology as autoradiography micropuncture, microinjection had to be performed to localize the action of the drug along the nephron. It was also discussed of the use of isolated perfused kidney as a tool in drug disposition and the use of renal cells culture. A better understanding of the mechanisms of direct renal toxicity of drugs was obtained from the results of experimental models. It is not so easy, at the present time, to know the mechanisms of immunological drug-induced nephrotoxicity. It seems necessary to develop new experimental models. The results obtained in animals with Cl2Hg or D. Penicillamine or gold salts afford to suspect some mechanisms for these types of nephropathies. This aspect of drug induced nephropathy is more complex because there is a large interindividual variation in susceptibility to these drugs.

Animals↗
PubMed1986

[Presentation of data in drug surveillance and bases for a decision].

Data presentation is a fundamental step in drug surveillance, for it makes it possible, after methodical analysis of the information obtained, to draw conclusions which may lead to a final decision concerning the product. Several items providing the basis for such decisions are discussed.

Evaluation Studies as Topic↗
PubMed1985

Suppression of arrhythmias within hours after a single oral dose of amiodarone and relation to plasma and myocardial concentrations.

In 65 patients a single oral dose of amiodarone (30 mg/kg) produced an antiarrhythmic effect on supraventricular or ventricular arrhythmias within 3 to 8 hours and lasted for 17 to 19 hours. On the second day a 15-mg/kg dose reproduced this effect within 3 to 9 hours. Plasma concentration of amiodarone increased to a maximum (2.2 +/- 1.7 mg/liter) mean +/- standard deviation) at 6 +/- 3.5 hours and plasma levels of N-desethylamiodarone (NDA) rose to 0.2 +/- 0.08 mg/liter at 12 +/- 6.4 hours. Sixty-one other patients were given a single 30-mg/kg dose 7 hours to 4 days before open heart surgery. Biopsies of the right atrial and left ventricular walls were taken during surgery. Myocardial concentration of amiodarone was maximal in the atrium after 7 hours (13 +/- 8 mg/kg) and in the ventricle after 24 hours (17 +/- 11 mg/kg). NDA myocardial concentration increased progressively until 24 hours and then remained stable over 4 days (1.5 mg/kg). The amiodarone myocardial to plasma concentration ratio was similar in the atrium and in the ventricle and averaged 22 and 10 for amiodarone and NDA, respectively. A significant relation existed between amiodarone concentration and the effect on ventricular premature complexes (r = 0.74, p less than 0.001) and between amiodarone plasma concentration and the effect on the atrioventricular conduction (r = 0.58, p less than 0.001). The plasma concentration of amiodarone corresponding to a 60% decrease in arrhythmias averaged 1.5 to 2 mg/liter.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1982

[Prognostic factors in acute digitalis poisoning].

The prognostic significance of various clinical and biochemical factors was investigated in 179 patients who had ingested more than 2 mg digitoxin. The mortality rate in this series was 17%. Supraventricular arrythmias had no influence on prognosis, but the death risk was higher in males and in patients with AV block. It increased with age, with digitoxin and potassium serum levels and even more with persistent hyperkalemia. Two other factors--previous heart disease and vomiting--were also significant in patients without heart block. Calculated on the basis of 4 clinical factors, the mortality rate varied from 2 to 74%. The death risk in acute digitalis poisoning can therefore be easily assessed simply from clinical criteria.

Acute Disease↗
PubMed1981

[Prognostic factors in acute digitalis poisoning (author's transl)].

The prognostic significance of various clinical and biochemical factors was investigated in 179 patients who had absorbed more than 2 mg of digitoxin. The mortality rate in this series was 17%. Supraventricular arrythmias had no influence on prognosis, but the death risk was higher in males and in patients with A-V block. It increased with age, with digitoxin and potassium serum levels and even more with persistent hyperkalemia. Two other factors, previous heart disease and vomiting, were also significant in patients without heart block. Calculated on the basis of 4 clinical factors, the mortality rate varied from 2 to 74%. The death risk in acute digitalis poisoning can therefore be easily assessed from simple clinical criteria.

Acute Disease↗
PubMed1980

[Benzodiazepine physical dependence. 6 cases (author's transl)].

The symptoms include, by ascending order of severity: nightmares and insomnia, nausea and vomiting, muscular weakness or tremor, postural hypotension, hyperthermia, muscle twitching, convulsions, confusional state or psychosis. Prominent features are the late onset of these symptoms, several days after treatment has been discontinued, and the sometimes difficult diagnosis, since patients are usually unaware of their dependence on these drugs. Reinstituting benzodiazepine treatment, then withdrawing it progressively are the best curative measures. Prevention is easy if treatment is gradually rather than abruptly withdrawn in all patients who receive the compound in high dosage for more than one month.

Adult↗