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Biomedical subjects

A Astier

Publications and source records attributed to A Astier.

At least 109 records · Page 6Linked to original sources
PubMed1982

Sensitive high-performance liquid chromatographic determination of indomethacin in human plasma. Pharmacokinetic studies after single oral dose.

A sensitive high-performance liquid chromatographic assay for the specific determination of indomethacin at concentrations down to 20 ng/ml in human plasma is described. This method has been applied to investigate the disappearance of indomethacin from plasma of ten subjects following the intake of two formulations (Indocid and generic form). An initial half-life of 1.32 +/- 0.44 h-1 was found which is in good agreement with other findings, but the terminal phase was much longer (13.6 +/- 6.9 h-1) than previously reported. There is no difference between the two galenic forms (p less than 0.001).

Chromatography, High Pressure Liquid↗
PubMed1980

[Correlations between alcohol ingestion, blood alcohol levels and behavior problems].

Behaviour changes in 20 young adults subjected to an alcohol tolerance test finding a blood alcohol level of the order of 80 mg.l-1 were assessed using a series of tests exploring certain qualities required in a vehicle driver, in particular capacity for focalisation of attention, possibilities of acquisition of new information, short-term memory with a visual support, the quality of motor reflexes and conscious level as involved in postural regulation. Results showed an absence of correlation between the amount of alcohol ingested (0.5 g.kg-1 of alcohol in the form of commercial Vodka) and resultant blood alcohol levels measured at the 30 th minute, or at the 102 minute after ingestion. However, they above all showed that there was virtually no correlation between blood alcohol level and behavioural modifications. In some instances, such modifications went even in the direction of an improvement, notably in terms of focalisation of attention in the majority of cases and postural tonic activity in some cases. However, certain individuals with "legal" blood alcohol levels showed evidence of behaviour which could be dangerous at the wheel of a car.

Adult↗
PubMedDate not supplied

Rapid determination of O- and P-cresol isomers in urine from workers exposed to toluene by high-performance liquid chromatography using a graphitized carbon column.

A simple and rapid procedure is described that permits the simultaneous determination of o- and p-cresol in urine of workers of other individuals exposed to toluene. The urine samples are enzymatically hydrolysed and analysed by high-performance liquid-chromatography with a detection limit of 0.2 mg/L, one fifth of the biological threshold limit value for o-cresol (1 mg/g), a specific marker of toluene exposure. A graphitized carbon column Hybercarb-S, that exhibits an excellent selectivity for aromatic positional isomers, was used with 1% phosphoric acid-acetonitrile (70:30, v/v) as mobile phase and a detection wavelength of 271 nm. The overall accuracy for o-cresol determination was 4.5% at 5 mg/L and 8% at 0.5 mg/L. The cresol isomers were sufficiently resolved from endogenous materials to avoid the need for any extraction step, and the method appears suitable for monitoring workers accurately under the permissible level of exposure for occupational medicine purpose.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Cyanide poisoning from propionitrile exposure.

A 55-year-old worker was exposed to propionitrile by both the inhalational and dermal routes. He rapidly lost consciousness and developed metabolic acidosis consistent with cyanide poisoning. Treatment with hydroxycobalamin and sodium thiosulfate produced complete symptom resolution within an hour. Serial blood cyanide and thiocyanate levels documented a rapid decrease in cyanide and concomitant increase in thiocyanate. Serious cyanide poisoning can occur from propionitrile exposure. Treatment with hydroxycobalamin and sodium thiosulfate can produce rapid clinical improvement.

Cyanides↗
PubMedDate not supplied

Cyclodextrin inclusion complexes of the central analgesic drug nefopam.

Inclusion complexes of nefopam base (NEF) with various beta-cyclodextrins (betaCDs) were investigated. All tested betaCDs increased the apparent solubility of NEF according to a Higuchi AL type plot (except betaCD: AN type plot), which indicates the formation of 1:1 stoichiometry inclusion complexes. 1H-NMR and 13C-NMR experiments showed that complexation by CDs allowed an easy separation of the R and S enantiomers. Based on spectral data obtained from the two-dimensional rotating frame nuclear Overhauser effect spectroscopy (2D-ROESY), a reasonable geometry for the complexes could be proposed implicating the insertion of the benzoxazocine ring into the wide end of the torus cavity.

Administration, Sublingual↗
PubMedDate not supplied

Cyanide assay: statistical comparison of a new gas chromatographic calibration method versus the classical spectrophotometric method.

This work compares two different methods for assaying hydrogen cyanide, a spectrophotometric method and a headspace gas chromatographic method, each with its own reference standard generation. In the first method, the reference standards are cyanide solutions. In the second method, the reference standards are based upon the in situ reduction of ethyl thiocyanate by dithiothreitol to produce hydrogen cyanide. Furthermore, hydrogen cyanide concentration in the blood of patients who were poisoned by smoke inhalation or who committed suicide by cyanide ingestion is determined using both methods. Results are discussed using statistical comparison.

Calibration↗
PubMedDate not supplied

4-Methylpyrazole may be an alternative to ethanol therapy for ethylene glycol intoxication in man.

4-Methylpyrazole (4 MP) is a strong inhibitor of alcohol dehydrogenase. Its use in acute ethylene glycol (EG) or methanol intoxication has been suggested in experimental studies about its efficacy and safety. We report three cases of accidental intoxication with ethylene glycol in man treated orally with 20 mg/kg/day of 4 MP. The treatment was maintained until plasma EG concentrations became unmeasurable. The patients were admitted early during the course of the poisoning. Their neurological status was good. A slight metabolic acidosis observed in two cases was easily corrected and did not recur. Renal function remained normal in all cases. No patient underwent hemodialysis. On admission plasma EG concentrations were 24.2 mmol/l, 13 mmol/l and 9.7 mmol/l respectively. Plasma EG half-lives were 14.5, 11.5 and 14.75 hours respectively. Plasma oxalate concentrations and the rate of urine oxalate elimination, determined in two patients, were high on admission but quickly returned to normal. Concerning possible side effects of 4 MP, a skin rash was observed in one patient and a possible eosinophilia in the others. These three cases suggest that 4 MP may decrease the metabolic consequences of EG poisoning in man and may be of therapeutic value when administered early during the course of the intoxication before coma, seizures and organic renal failure have occurred.

Adult↗
PubMedDate not supplied

[Pharmacokinetic evaluation of a computerized target-controlled infusion system: application to propofol in orthopedic surgery].

PaMo 2.0, a type of software, includes a pharmacokinetic model for propofol in the adult. It allows both administration and monitoring of propofol target-controlled infusions. In order to evaluate PaMo 2.0, a prospective clinical trial compared, at defined infusion times, predicted and measured plasma propofol concentrations, in 28 patients programmed for hip-replacement surgery. A propofol plasma determination technique had first been validated, including high performance liquid chromatography with fluorescence detection. A statistical analysis based on correlation (r = 0.73), inaccuracy = 29.18 per cent, bias = 11.67 per cent, wobble = 19.15 per cent, and divergence = -0.06 per cent/min calculation, related to this system, has been carried out. PaMo 2.0 under-estimated plasma propofol concentrations. The convergence between predicted and measured propofol concentrations was good and not modified in respect of infusion time. This infusion system is suitable for propofol administration, but the integration of Bayesian pharmacokinetic models would greatly improve propofol plasma concentration estimation and regimen adaptation to each patient.

Adult↗
PubMedDate not supplied

[Evaluation of the heterogeneous immunoassay (ACMIA) for the measurement of blood cyclosporin on the Behring dimension RXL clinical chemistry analyzer].

We propose an evaluation of a new heterogeneous immunoassay of cyclosporin on RXL HM Dimension (Dade Behring) for therapeutic cyclosporin monitoring in whole-blood patients transplant. The pretreatment step is performed automatically into the apparatus while it is a manual step with EMIT. Linearity, intra- and inter-day precision, limit of quantification, precision and accuracy of dilution steps and stability into the equipment were studied. We realized the comparison between ACMIA and EMIT methods on whole-blood patients transplant recipients. Heterogeneous immunoassay showed a good linearity between 0 and 500 ng/mL, intra- and inter-day precision with coefficient of variation inferior to 7.2%. We observed reproducible and accurate dilutions of high concentrations (500 to 2,000 ng/mL). The correlation with EMIT technique was correct for different type of transplant (n=55).

Cyclosporine↗