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M Pays

Publications and source records attributed to M Pays.

11 recordsLinked to original sources
PubMed1992

Separation and identification of the 4-hydroxyantipyrine sulphoconjugate.

In a previous study we observed, during separation of total antipyrine metabolites by high-performance liquid chromatography and after enzymatic hydrolysis, an unidentified peak corresponding to an ionic compound with pyrazolinone features. In the present study, this compound was identified as the 4-hydroxyantipyrine sulphoconjugate, and its structure was definitively confirmed by gas chromatographic-mass spectrometric analysis and by the use of pure synthetic substance. We also demonstrated the inhibitory effect of sodium metabisulphite, a necessary preservative of urinary samples, on hydrolysis of this conjugate in the presence of sulphatases from Helix pomatia or Aerobacter aerogenes. This inhibitory effect makes it impossible to perform a global assay of antipyrine metabolites after enzymatic or chemical hydrolysis and confirms the value of direct assay of the 4-hydroxyantipyrine sulphoconjugate.

Adult↗
PubMed1992

Simultaneous determination of chloroquine and its three metabolites in human plasma, whole blood and urine by ion-pair high-performance liquid chromatography.

A method was developed for the separation and measurement of chloroquine and three metabolites (desethylchloroquine, bisdesethylchloroquine and 4-amino-7-chloroquinoline) in biological samples by ion-pair high-performance liquid chromatography with UV detection. The method uses 2,3-diaminoaphthalene as an internal standard and provides a limit of detection between 1 and 2 ng/ml for chloroquine and its metabolites. The assay was linear in the range 12.5-250 ng/ml and the analytical recovery and reproducibility were sufficient. The assay was applied to the analysis of biological samples from a patient undergoing chloroquine chemoprophylaxis and a patient who had ingested chloroquine in a suicide attempt.

Chloroquine↗
PubMed1992

Effect of a macrolide (spiramycin) on the pharmacokinetics of L-dopa and carbidopa in healthy volunteers.

In one well-equilibrated parkinsonian patient treated with combined L-dopa and carbidopa (Sinemet), we have observed changes in treatment efficacy while receiving spiramycin (Rovamycine) for an intercurrent respiratory infection. A preliminary study of the pharmacokinetics of L-dopa and its main metabolites 3-O-methyldopa (3-OMD) and dihydroxyphenylacetic acid (dopac) in two parkinsonian patients treated with Sinemet has revealed a marked decrease in the AUC0-360 of these two metabolites after a 3-day course of Rovamycine. In order to confirm this interaction, we have studied the modifications of the pharmacokinetics of L-dopa, 3-OMD, dopac, and carbidopa in eight male healthy volunteers after a single dose of Sinemet 250 (L-dopa, 250 mg and carbidopa, 25 mg) before and after a 3-day course of Rovamycine. Our study confirms this interaction. After spiramycin, we observed a marked reduction in AUC0-360 for L-dopa (p less than 0.001), 3-OMD (p less than 0.001), and carbidopa (p less than 0.001), and an increase in AUC0-360 for dopac (p less than 0.01). The L-dopa elimination half-life was increased (p less than 0.012); differences in peak plasma concentrations did not attain statistical significance. We think that these modifications in L-dopa pharmacokinetics after spiramycin are due to nonabsorption of carbidopa secondary to modified gastrointestinal motility.

Adult↗
PubMed1992

Compared plasma and brain pharmacokinetics of clomipramine and its metabolite demethylclomipramine in two strains of mice (NMRI and CD1).

The fate of clomipramine (CMI) and its main demethylated metabolite demethylclomipramine (DCMI) was studied in two strains of Swiss mice (NMRI and CD1) after intraperitoneal injection. A study of its distribution among various tissues showed that fixation was most marked in lungs, perirenal fat and kidneys, and only moderate in the brain. The pharmacokinetic parameters of both molecules were determined in brain tissue and plasma. Absorption was rapid (tmax CMI = 14 min), metabolism prompt (tmax DCMI = 17 or 18 min according to the breed) and elimination rapid from both plasma and brain tissue. The first two stages were similar in the two strains, but elimination of CMI from both plasma and brain was faster in the NMRI mice (plasma t1/2 = 53 min against 165 min in the CD1 mice). Both values were well below that reported for man (mean plasma t1/2 = 24 h). The data presented can serve as a basis for designing true chronic administration protocol in animals.

Animals↗
PubMed1991

Pharmacokinetics of molsidomine and its active metabolite, linsidomine, in patients with liver cirrhosis.

The pharmacokinetics of molsidomine were investigated in six healthy volunteers and in seven patients with alcoholic cirrhosis. After a 2 mg oral dose, molsidomine elimination half-life was prolonged in cirrhotic patients (13.1 +/- 10.0 h vs 1.2 +/- 0.2 h, P less than 0.01) because of a decrease in its apparent plasma clearance (CL/F) (39.8 +/- 31.9 ml h-1 kg-1 in patients with cirrhosis vs 590 +/- 73 ml h-1 kg-1 in volunteers). The elimination half-life of the active metabolite, linsidomine (SIN-1) was also prolonged in cirrhotic patients (7.5 +/- 5.4 h vs 1.0 +/- 0.19 h, P less than 0.05). The AUC values of both molsidomine and linsidomine were increased in the cirrhotic group, but the increase in the former was considerably greater than in the latter as shown by the significant decrease of the ratio AUClinsidomine/AUCmolsidomine x 100 (4.5 +/- 6.1 in cirrhotic patients vs 23.5 +/- 3.4 in healthy volunteers, P less than 0.001). These results suggest that liver cirrhosis profoundly alters the pharmacokinetics and metabolism of molsidomine.

Adult↗
PubMed1991

Penetration of minocycline into lung tissues.

The penetration of minocycline into different lung tissues and bronchial mucus was studied in 17 patients undergoing pulmonary surgery for cancer. The patients received oral minocycline 100 mg at night for 3 days preceding surgery. Minocycline concentrations were measured in plasma samples collected before the operation and in tissues and mucus taken from in and around the part of the lung that was surgically removed. Mean tissue or mucus concentration to plasma concentration ratios were 3.78 +/- 1.10 for lung parenchyma, 4.04 +/- 1.31 for bronchial walls, 3.37 +/- 1.00 for pulmonary arterial walls, 1.99 +/- 1.80 for intraluminal mucus collected from bronchi located in healthy tissue proximal to the tumour, 5.16 +/- 3.26 for intraluminal mucus collected in a bronchus distal to the tumour, and 3.06 +/- 1.99 for catheter-collected mucus from the trachea and principal bronchi. These results indicate that minocycline is found in high concentration in all types of lung tissue and mucus in man.

Adult↗
PubMed1991

Pharmacokinetics of molsidomine and of its active metabolite, SIN-1 (or linsidomine), in the elderly.

The pharmacokinetics of molsidomine were investigated in six young (25.5 +/- 0.6 years) and in six elderly healthy volunteers (81.1 +/- 3.1 years). After a 2 mg oral administration, molsidomine elimination half-life was prolonged in elderly subjects (1.9 +/- 0.2 h versus 1.2 +/- 0.1 h, P less than 0.05) because of a decrease in its plasma clearance (15.1 +/- 3.2 l.h-1 versus 41.8 +/- 2.5 l.h-1 (P less than 0.01) in young volunteers). The elimination half-life of the active metabolite, SIN-1 or linsidomine was also prolonged in elderly subjects (1.8 +/- 0.2 h versus 1.0 +/- 0.08 h, P less than 0.05). AUCs of both molsidomine and SIN-1 were increased in the elderly subjects, but the increase in the former was greater (x 3.4) than the increase in the latter (x 1.6). These results suggest that pharmacokinetics and metabolism of molsidomine are impaired in elderly subjects.

Administration, Oral↗
PubMed1979

[Isolation and identification of psychotropic drugs by circular chromatography (author's transl)].

The "SelectaSol Solvent System" manufactured by SCHLEICHER and SCHULL is convenient for practical circular chromatography. These new possibilities are suitable to the rapid determination of psychotropic drugs in biological fluids of patients in emergency clinical toxicology. We are comparing circular and linear techniques with regard to the choice of solvent systems, diffusion time, isolation and characterization of implicated drugs.

Antidepressive Agents, Tricyclic↗
PubMed1979

[Erythrocyte bilirubin determination (author's transl)].

The erythrocyte bilirubin value is of great interest in neonate pathology. Its sudden rising reflects the overbinding capacity to plasmatic albumin. A colorimetric, simple and accurate micromethod with 2-hydrazino-benzothiazol as reagent leads to its quantitative determination. Hemolysis interference is removed. The authors have determined a mean value of erythrocyte bilirubin/total plasmatic bilirubin ratio for newborn population without clinical or biological risks of kernicterus.

Bilirubin↗
PubMedDate not supplied

[Diffusion of minocycline in pulmonary tissue].

The penetration of minocycline into lung tissue was evaluated in 14 patients about to undergo excision of the lung for cancer. The patients received minocycline orally in doses of 100 mg twice a day for 3 days, the 100 mg in the morning of the operation day. Minocycline concentrations were measured in plasma samples taken before surgery and in the lung tissue resected. The mean tissue/plasma concentration ration was 3.17 +/- 0.41 (range: 1.5 to 7.48). The same ratios were obtained in peritumoral and tumoral tissues. These results indicate that minocycline penetrates well into tissues.

Adenocarcinoma↗