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D Leveque

Publications and source records attributed to D Leveque.

10 recordsLinked to original sources

High-performance liquid chromatographic assay for meropenem in serum.

High-performance liquid chromatographic procedures have been developed for the measurement of meropenem in serum. The separation was performed on an Ultrasphere XL-ODS analytical column (75 x 4.6 min I.D.). The mobile phase consisted of 10.53 mmol/l ammonium acetate-acetonitrile (95:5, v/v) (pH 4). The UV detection was at 298 nm. The quantitation limit both in serum and water was 0.25 micrograms/ml. The method was validated in serum and aqueous solution over the concentration range 0.25-50 micrograms/ml. The extraction recovery from serum spiked with meropenem was 99.7 +/- 3.4%. The intra- and inter-assay coefficients of variation were below 6%. Stored at -80 degrees C for three months at various concentrations in serum and in aqueous solution, meropenem did not reveal any appreciable degradation. After 24 h, it was also stable at 4 degrees C in serum, aqueous solution and supernatant of extraction but not at room temperature. The stability of the drug was also confirmed in serum after repeated freezing-thawing cycles at -80 degrees C on four consecutive days.

Animals↗

Pharmacokinetic and preliminary metabolic fate of navelbine in humans as determined by high performance liquid chromatography.

The pharmacokinetics and metabolism of Navelbine (NVB) were investigated in 20 patients by a specific high performance liquid chromatographic methodology allowing the monitoring of NVB, deacetyl-NVB, and N-oxide NVB. After the i.v. (15 min) administration of 30 mg/m2 of drug, blood and urine samples were collected for, respectively, 144 and 48 h. NVB is characterized by a three compartmental kinetics, with a Cmax of 1130 +/- 139 (SEM) ng/ml. The total body clearance and apparent volume of distribution, as defined by high performance liquid chromatography, are 1.26 +/- 0.09 liter/h/kg (48.6 +/- 4.1 liters/h/m2) and 75.6 +/- 9.2 liters/kg (2918.4 +/- 307.2 liters/m2). No metabolite could be detected in serum; the urinary excretion of NVB represented 11% of the administered dose. Deacetyl-NVB could be identified as a minor urinary metabolite when no N-oxide NVB appeared in the urine samples. Two additional peaks appeared in most of urinary chromatograms as trace amounts. Thus, the major pathway of NVB, as for other Vinca alkaloids, should be hepatic clearance, as biliary elimination and/or hepatic biotransformation.

Adult↗

Vascular origin of Poland syndrome? A comparative rheographic study of the vascularisation of the arms in eight patients.

Vascularization of the arms has been studied by impedance plethysmography (rheography) in eight children with Poland syndrome, a common malformation characterized by unilateral hand anomaly and ipsilateral aplasia of the inferior head of the pectoralis major muscle. A marked decrease of the velocity of the systolic increase in the arterial volume (Velm) was shown in the affected arms, and the difference between the two arms was significantly higher in the patients than in a control group (P less than 0.02). These results, which are also observed in stenotic atherosclerosis, support the hypothesis of hypoplasia of the ipsilateral subclavian artery as the origin of the malformation, although a local anomaly in arterial-wall viscosity cannot be ruled out. The opacification of the aortic arch in another patient confirmed this hypothesis. Aortography in further patients will be necessary to substantiate our results. However, this technique is not without danger and should only be used during the first months of life when a vascular operation can be envisaged.

Adolescent↗

[Cardiac manifestations of scleroderma. Prospective study of thirty cases (author's transl)].

A prospective study was conducted to evaluate cardiac effects of scleroderma by means of phonomyography (30 patients) and ultrasound cardiography (18 patients). Clinically silent effusions can be detected by ultrasound cardiography, and 50 p. cent of the patients were found to have pericarditis through this investigative technique. Valvular lesions (mitral prolapsus) were present in a more important number than simply a coincidence. Measurement of myocardial relaxation appears to give the best indication of the specific myocardial lesion in this disease, and even may be of some prognostic value.

Adult↗

Pharmacodynamics of 5-fluorouracil combined with carboplatin in patients with head and neck cancer.

The objective of our work was to investigate the pharmacodynamics of 5-fluorouracil (5-FU) in 23 patients with head and neck cancer treated with carboplatin (360 mg/m2) followed by 5 day continuous infusion of 5-FU (lg/m2/day). The pharmacokinetic profile of 5-FU was characterized for 36 cycles and was compared with the patient's tolerance. Toxic cycles (> or = grade 1, WHO grading) were associated with higher values of area under the serum concentration-time curve (AUC) than those of non toxic cycles. In addition, AUC values of 37000 ng.h.ml-1 and 21000 ng.h.ml-1 for the entire cycle and the half-cycle respectively were found to be predictive of toxicity. These threshold values are identical to those determined in our previous study with the cisplatin-5-FU regimen. Hence, patients treated with carboplatin and infusional 5-FU might benefit from 5-FU blood level, monitoring using the same dose adjustment diagram.

Adult↗