Publications by authors named "Mahuzier G"

Background: The self-medication hypothesis is commonly put forward to explain the high prevalence of smoking in psychiatric patients. However, studies supporting the self-medication hypothesis have most often been carried out on chronic patients stabilized by antipsychotics.

Aim: Given that antipsychotics tend to erase psychiatric symptoms, the present study was undertaken on acutely ill patients usually receiving no medications, or on whom medications are ineffective.

View Article and Find Full Text PDF

Benzodiazepines are some of the most often co-abused substances in methadone treatment. Their identification in biological samples is of great importance in toxicological screening and in methadone maintenance program. The aim of this report is to describe, the analytical data making possible the identification of benzodiazepines and/or metabolites using a reversed phase liquid chromatography coupled with diode array detection.

View Article and Find Full Text PDF

Background: Asking psychiatric in-patients about their drug consumption is unlikely to yield reliable results, particularly where alcohol and illicit drug use is involved. The main aim of this study was to compare spontaneous self-reports of drug use in hospitalized psychiatric patients to biological measures of same. A secondary aim was to determine which personal factors were associated with the use of tobacco, alcohol, and illicit drugs as indicated by these biological measures.

View Article and Find Full Text PDF

HPLC using fluorescence detection has already become the most accepted method for the determination of aflatoxins due to its several advantages over other analytical methods. Both normal- and reversed-phase HPLC can be used. However the reversed-phase HPLC methods are more popular.

View Article and Find Full Text PDF

The photochemically induced fluorescence (PIF) properties of tianeptine and some of its metabolites were investigated in acidic (pH 2.3) water-alcohol mixtures at room temperature. Two PIF methods were developed, including bulk solution and flow injection analysis (FIA).

View Article and Find Full Text PDF

Cerium is used for its antiseptic and immunomodulatory properties in burn injury. We have developed a cerium-doped clay to replace existing ointments. Adsorption and release of cerium (Ce3+) by diosmectite were studied at 22+/-2 degrees C, in the presence of various other cationic species.

View Article and Find Full Text PDF

The fluorescence properties of the aflatoxins M1, Q1, P1 in solution and the effect of various cyclodextrins (alpha-, beta-, gamma-, hydroxypropyl-beta- and alpha-beta-heptakis-di-O-methyl-beta-) on their fluorescence emission were studied. Among the aflatoxins, a substantial enhancement of the fluorescence emission of aflatoxin Q1 in the presence of aqueous solutions of alpha-, beta-, hydroxypropyl-beta, and alpha-beta-heptakis-di-O-methyl-beta-cyclodextrin, was observed. On the contrary, gamma-cyclodextrin proved to be inefficient to enhance the fluorescence properties of this compound.

View Article and Find Full Text PDF

Some epoxyethane-/ethynesulfonamides had shown strong filaricidal activity with inconstant reproducibility as a result of a lack of stability in aqueous solution. The degradation in hydroxylic and aprotic solutions of two epoxyethanesulfonamides and one ethynesulfonamide was investigated using TLC, HPLC, GC and mass spectrometry. For both epoxydes, the degradation rate followed first-order kinetics and was more rapid in hydroxylic than in aprotic solutions.

View Article and Find Full Text PDF

Lanthanide sensitized luminescence is a very attractive alternative to UV detection and other luminescence techniques, i.e., fluorescence and phosphorescence, in separation science for the detection of drugs and xenobiotics because of the large Stokes shift, narrow emission bands and long lifetime.

View Article and Find Full Text PDF

1. The tissue distribution and metabolism of a new filaricidal agent P903 (N-[(2-phenylethynyl)sulfonyl]morpholine) were studied in rat. 2.

View Article and Find Full Text PDF

The fluorescence properties of five substituted benzamides, including alizapride, metoclopramide, sulpiride, sultopride and tiapride, were investigated at several pH values and in various solvents (dimethyl sulfoxide, ethanol, ethylene glycol, methanol, propan-2-ol, tetrahydrofuran and water). Except for alizapride, the fluorescence intensities were found to be higher at acidic (1-6) than at alkaline (8-12) pH values. Using the optimum solvent (aqueous solutions) and appropriate pH conditions, linear spectrofluorimetric calibration curves were established over a concentration range of about two orders of magnitude, with correlation coefficients larger than 0.

View Article and Find Full Text PDF

A new and highly sensitive method for the detection of the important mycotoxin, citrinin, has been developed. Spectroscopic studies demonstrate that the fluorescence of this metabolite is influenced by the pH of the environment. This fact was exploited in the chromatographic determination of citrinin with fluorescence detection.

View Article and Find Full Text PDF

Measurement of fluorescence increase was used for the comparative quantification of the effect that several cyclodextrins (alpha-, beta-, heptakis-2,6-beta-omicron-dimethyl- and gamma-) produce on the fluorescent response of aflatoxins B1 and G1. This constitutes a new chromatographic method with stability of the mobile phase, and shows general improvements in the chromatographic conditions with respect to other methods (especially those using an iodine reservoir as a postcolumn reactor). A C18-type column was used, with methanol-water (60:40, v/v) as the mobile phase.

View Article and Find Full Text PDF

Diacetyl, in deaerated solutions, is a major room temperature phosphorescent compound. Its phosphorescence quenching is proposed in order to quantify results on phenothiazine derivatives. It is established from the luminescent data on phenothiazines that diacetyl phosphorescence can be quenched quantitatively by these compounds.

View Article and Find Full Text PDF

Therapeutic monitoring of patients participating in methadone maintenance programmes requires the qualitative or quantitative determination of methadone in urine before and during treatment. Generally immunoassay techniques are used for this determination, but more and more often measurement of plasma or serum levels are required by the physician. The possibility of adapting a commercially available FPIA kit (TDX ABBOTT) for urinary assays to the serum determinations was investigated.

View Article and Find Full Text PDF

Antibiotic susceptibility of 948 bacterial strains isolated from varied samples essentially proceeding from urinary infections in five Paris psychiatric Hospitals was determined by disk diffusion method. E. coli, P.

View Article and Find Full Text PDF

Cyclosporin A (CsA) is in vivo mainly metabolized by hepatic cytochrome P450 IIIA to more than 21 metabolites, the major ones known as: M1, M17 and M21. The aim of this work is to explore the in vitro metabolism of CsA after incubation, in the presence of NADPH, with renal or hepatic microsomes obtained from rabbits pretreated with rifampycin (enzyme inducer) or erythromycin (enzyme inhibitor). The presumed metabolites were separated by semi-preparative high-performance liquid chromatography (HPLC) and identified in each collected fraction by fluorescence polarization immunoassay (FPIA) (HPLC-FPIA) using a non-specific polyclonal antibody.

View Article and Find Full Text PDF

Chemiluminescence avoiding the fluctuations of the light of excitation, Rayleigh and Raman scattering, allows to get detection threshold 100 to 1,000 times lower than fluorimetry. Processes using the luminol, lucigenin, aryloxalic esters and ozone are employed in liquid chromatographic detection. Some pharmaceutical, biological and toxicological examples illustrate their applications.

View Article and Find Full Text PDF

Capillary zone electrophoresis with indirect ultraviolet detection was used for the determination of fosfomycin in serum. Running buffer consisted of a mixture of 200 mM sodium borate with 10 mM phenylphosphonic acid used as ultraviolet absorbing background electrolyte. Relationships between the pH of the buffer and the efficiency of the separation (migration times and selectivities) or the sensitivity of detection were investigated.

View Article and Find Full Text PDF

The emissions of light by biorganisms or these obtained by alchemists were known since long time ago but the are used in analytical chemistry only when STOKES discovered that the intensity of this light was proportional to the quantity of the matter. The very large sensibilities reached, associated with the great separation's ability of the liquid chromatography allows to develop new processes for quantification of very low concentrations of luminescent or no luminescent molecules. Many pharmaceutical, biological toxicological environmental or alimentary applications show that it is possible in liquid chromatography to obtain a detection limit about the pico or femtomole when simple chemical process are used: direct potentialization of luminescence by addition of modifiers of the chemical environment of the analytes: solvents, cyclodextrins, surfactants, metallic ions, indirect potentialization of the luminescence by transfer of energy from an excited molecule: sensitized fluorescence and phosphorescence, excitation of the molecule by a chemical reaction or chemiluminescence.

View Article and Find Full Text PDF

Under the words of sensitized luminescence, the processes who include the transfers of energy from a donor to an acceptor are described. They are to the origin of new possibilities of detection in liquid chromatography by emission or inhibition of phosphorescence and fluorescence. These news technologies are illustrated by examples in pharmaceutic, biologic or food applications.

View Article and Find Full Text PDF

We report an analytical reversed-phase liquid-chromatographic procedure for quantifying nicotine and cotinine in urine, taking into account the presence of interfering caffeine frequently encountered in such specimens. These analytes are extracted from the alkalinized urine with chloroform. After evaporation of the chloroform, the residue is dissolved in methanol and injected into a chromatographic C18 column.

View Article and Find Full Text PDF

Fast atom bombardment-tandem mass spectrometry was used to identify molecular species of paf-acether (paf) produced by human polymorphonuclear neutrophils. Using this biological material, normal phase high performance liquid chromatography was necessary prior to the fast atom bombardment-tandem mass spectrometry step. Gas liquid chromatography/electron capture detection after hydrolysis with phospholipase C and conversion to heptafluorobutyrate derivatives was used to confirm the results.

View Article and Find Full Text PDF