PubMed Health⌕ Search

Biomedical subjects

D Lamiable

Publications and source records attributed to D Lamiable.

At least 37 records · Page 2Linked to original sources
PubMed1995

Urinary excretion of cicletanine in the rat. Stereochemical aspects.

The metabolism of (+)-cicletanine and (-)-cicletanine (10 mg kg-1) was studied in healthy male Wistar rats 24 hr after a single dose and following daily oral administration for 25 days. Urine, collected in 24-hr intervals on days 1, 5, 10, 15, 20, and 25, was analyzed by an HPLC method for parent drug and its sulfate/glucuronide conjugates. In urine, the sulfate and glucuronide conjugates of cicletanine were the only two major components quantitated; parent drug was a minor component. Within 24 hr after the first dose of (+)-cicletanine, the sulfate conjugate was the major urinary component; the ratio of sulfate to glucuronide conjugate was 3. After oral administration of (-)-cicletanine, the glucuronide and sulfate conjugates were present in similar amounts. For each enantiomer, the ratio of sulfate/glucuronide did not change upon multiple dosing, and inversion of the enantiomers did not occur. Although sulfate and glucuronide conjugates of each enantiomer are formed, the relative amounts of each conjugate depends on the enantiomer, indicating that there is stereospecificity in the disposition of cicletanine.

Animals↗
PubMed1994

Comparative pharmacokinetics of two diastereoisomers dexamethasone and betamethasone in plasma and cerebrospinal fluid in rabbits.

The two diastereoisomers dexamethasone (DXM) and betamethasone (BTM) were infused at two different doses (2, 10 mg.kg-1) in anesthetized rabbits. Samples of plasma and cerebrospinal fluid were collected over a 180-min period. Steroid concentrations were measured by high performance liquid chromatography. The terminal half life (85.7 +/- 20.8 min and 102.2 +/- 29.6 min for DXM; 117.6 +/- 19.8 min and 118.5 +/- 15.8 min for BTM) and the mean residence time (121.4 +/- 27.7 min and 146.1 +/- 41.3 min for DXM; 168.6 +/- 28.1 min and 172.2 +/- 20.6 min for BTM) were unchanged between the doses. Dose-dependent changes in the area under the curve normalized by the dose, then volume distribution and clearance were observed. The average percentage of DXM and BTM bound to plasma proteins were 78.1 +/- 11.5% and 88.3 +/- 5.1% respectively at the lower dose, and decreased significantly with 10 mg.kg-1. DXM appeared more rapidly in the CSF, the highest concentrations of DXM were obtained within 15 min after the end of the injection. The CSF levels were lower than that of plasma unbound and the passage through the blood-brain barrier was saturable. These results will complicate pharmacokinetic and pharmacodynamic analysis.

Animals↗
PubMed1994

Gallium chloride effects on neonatal rat heart cells in culture, in standard and oxidative conditions.

The effects of gallium chloride (GaCl3) at 7.17, 28.68 and 114.7 microns (0.5, 2 and 8 mg/l of Ga3+) were checked in cardiac cells derived from 2-4 day-old newborn rats, cultured for 72 h in Eagle's minimum essential medium (MEM), enriched with 10% foetal calf serum (v/v) and 2 mM of glutamine at 37 degrees C, with 95% air plus 5% CO2. After 3 hours of standard culture conditions (MEM with glucose 5 mM), Ga treatment induced an increase of glycogen stores without any influence on ATP, ADP, and AMP concentrations. A slight and transient decrease in the beat rate was noted after 15 min of exposure to GaCl3 at all concentrations, whereas there was no difference in the beat rate nor in the cell contraction amplitude after 3 hours of exposure. After 1.5 h in conditions of oxidation (Tyrode solution without glucose, FeCl2 20 microM, ascorbic acid 0.2 mM), GaCl3 at 8 mg/l decreased the malondialdehyde (MDA) production as assessed by the decrease of intracellular concentrations and the decrease of its release in the supernatant. The decreased MDA production following oxidative stress, the increase in glycogen stores in normal oxygen concentrations, as well as the maintenance of ATP concentrations and the lack of any chronotropic effect induced by GaCl3 suggests a protective rather than a deleterious cardiac effect.

Animals↗
PubMed1994

Pharmacokinetics and brain distribution of zolpidem in the rat after acute and chronic administration.

The pharmacokinetics of zolpidem were studied after single dose, administered for either 7 or 28 days to rats. Thirty minutes after the last dose, animals were killed and the brain removed. The highest concentrations in plasma, which were observed at the first sampling time (0.5 h) were 2341 +/- 540 (day 0), 1956 +/- 325 (day 7) and 2908 +/- 1369 ng mL-1 (day 28). Corresponding AUC values of 1742 +/- 488, 1583 +/- 422 and 2683 +/- 1249 ng mL-1 h were found. MRT increased significantly from 0.46 +/- 0.06 h on day 0 to 0.67 +/- 0.02 h on day 28. The cerebral levels showed no significant change during the chronic administration (766 +/- 285, 685 +/- 171 and 887 +/- 264 ng g-1, respectively). No modification of the principal kinetic parameters was detected up to the 28th day of treatment.

Animals↗
PubMed1994

Linear pharmacokinetics of a new inotropic agent.

The dose-dependent pharmacokinetics of N,N'-dicyclopropyl-methyl-piperazine- dichlorhydrate (Ino 2628 CZ, CAS 82909-97-5), a new inotropic compound, was studied after 4 intravenous infusions in 3 subjects and 4 orally administered doses in 6 subjects. Plasma and urine levels were determined over 72 h. The results show that the pharmacokinetics of Ino 2628 CZ was dose proportional over the intravenous and oral dose range of 100 to 400 mg.

Administration, Oral↗
PubMed1993

Sensitive high-performance liquid chromatographic method for the determination of coumarin in plasma.

A high-performance liquid chromatographic method was developed for the determination of coumarin in plasma at low concentrations. The method involves a single-step extraction of the alkalinized sample with hexane and subsequent evaporation of the organic phase in the presence of hydrochloric acid to collect and concentrate the coumarin. Analysis of the acidic phase was performed on a C8 column and coumarin was detected by measuring the UV absorbance at 275 nm. The limit of detection was 0.3 microgram l-1. The assay was used to study the evolution of concentrations of coumarin in one volunteer after oral administration of a single 10-mg dose.

Calibration↗
PubMed1993

Gas chromatographic determination of meprobamate in human plasma.

A simplified and rapid gas chromatographic method has been developed for the determination of meprobamate in human plasma. The procedure includes a single-step extraction of alkalinized sample with chloroform, and chromatography on a non-polar fused-silica capillary column with flame ionization detection. The method is accurate (97.7 +/- 5.7% at 20 mg/l) and precise (maximum coefficient of variation of 9.5%). It provides an alternative to existing methods and is particularly suitable for toxicological studies.

Aged↗
PubMed1992

Toloxatone pharmacokinetics in the plasma and cerebrospinal fluid of the rabbit.

The pharmacokinetics of toloxatone (5 and 10 mg kg-1, i.v.) was studied in anaesthetized rabbits. There was a biexponential decline in plasma concentration with time. No differences were observed in the pharmacokinetic parameters with the increase of the dose. The terminal half-life was short (47.4 +/- 2.8 and 41.5 +/- 4.2 min for 5 and 10 mg kg-1, respectively). The total clearance was 79 +/- 18 mL min-1 after a dose of 5 mg kg-1 and 106 +/- 40 mL min-1 after a dose of 10 mg kg-1. The volume of distribution was 5.8 +/- 2.8 (5 mg kg-1) and 5.4 +/- 1.8 L (10 mg kg-1). The average percentage of toloxatone bound to plasma protein was 30% and was not affected by concentrations within the investigated range. In cerebrospinal fluid (CSF), the highest concentrations of toloxatone were obtained within 15 min after the end of the injection. The CSF level of toloxatone was equal to that of plasma unbound toloxatone and declined at a rate similar to toloxatone in plasma. These results suggest that the toloxatone passage through the blood-brain barrier may be completed by passive diffusion. In addition, the unbound plasma concentration would accurately reflect the toloxatone concentration in CSF and could be a useful tool for drug monitoring.

Animals↗
PubMed1991

[Treatment of legionellosis with ofloxacin in kidney transplanted patients. Lack of interaction with cyclosporin A].

Seven cases of legionellosis were observed in a series of 81 renal transplant recipients. In the 6 patients with functional graft, pneumonia occurred 17 days on average after the beginning of transplant rejection treatment. The diagnosis was made by bronchoalveolar lavage: the direct immunofluorescence antigen technique was positive in 5 cases and culture in 6 cases. Legionella pneumophila sero-groups 5 and 1 were identified in one and 5 patients respectively. Six of the 7 patients were treated with ofloxacin. This fluoroquinolone was effective in all cases. It was administered as single therapy in 3 patients and did not interfere with ciclosporin A metabolism. Ofloxacin given in mean doses of 400 mg per day adjusted to renal function proved to be a simple, effective and well tolerated treatment of legionellosis in transplant recipients receiving ciclosporin A.

Adult↗
PubMed1991

Influence of sex and oestrogen replacement on the disposition of dexamethasone in rats.

The disposition of dexamethasone (DXM, 2 mg/kg, iv) was studied in ovariectomized female rats treated with oestrogen (0.1 mg and 1 mg of oestradiol benzoate) and in male rats. Oestradiol replacement had no effect on body or liver weights or on the DXM pharmacokinetic parameters (CL, Vdss, AUC, MRT and t1/2) of the female groups. If the Vdss seemed slightly greater in male than in female rats, this difference disappeared after normalization based on body weight. In contrast, CL was greater in the male rats even after normalization. For all the animals, significant correlations were observed between body weight and Vdss (r = 0.731, P less than 0.001) or CL (r = 0.639, P less than 0.001). Terminal half life and MRT were negatively correlated with CL (r = -0.481, P less than 0.01 and r = -0.575, P less than 0.01, respectively) but not with Vdss. Although oestrogen replacement did not seem to affect the pharmacokinetics of DXM, the increase in the CL in male rats should be the main determinant observed between the sexes. These results are consistent with a slower metabolism found for various drugs metabolized by the cytochrome P-450 in female rats.

Analysis of Variance↗
PubMed1990

Lack of interaction between disulfiram and alprazolam in alcoholic patients.

Certain interactions between disulfiram and benzodiazepines, especially diazepam and chlordiazepoxide, have previously been reported. The influence of disulfiram on the pharmacokinetics of alprazolam, a triazolobenzodiazepine, metabolized by hepatic microsomal oxidation, has been evaluated in 11 chronic alcoholic patients (6 males, 5 females) undergoing treatment for the alcohol withdrawal syndrome. Each patient received alprazolam 2 mg on the first day (control) followed by two weeks of treatment with disulfiram 0.5 g/d, and then further oral dose of alprazolam 2 mg. No significant change was found in any of the kinetic parameters. Thus, a therapeutic dose of disulfiram did not significantly alter the clearance or half-life of alprazolam in chronic alcoholic patients.

Adult↗
PubMed1989

Simple high-performance liquid chromatographic method for the measurement of toloxatone in rabbit cerebrospinal fluid and plasma.

A simplified, rapid high-performance liquid chromatographic procedure has been developed for the measurement of toloxatone in rabbit plasma and cerebrospinal fluid. The method involves a single-step extraction of the alkalinized sample with diethyl ether and analysis of the evaporated extract on a C8 column. Detection was performed by ultraviolet absorbance monitored at 240 nm. The overall run-time of the assay was 8 min at a flow-rate of 1 ml min-1. The sensitivity limit of toloxatone was 70 ng ml-1 at a signal-to-noise ratio of 3:1 in rabbit cerebrospinal fluid and plasma. The assay has been used to define plasma toloxatone concentration-time profiles and to quantitate cerebrospinal fluid toloxatone levels after a single intravenous injection in rabbits.

Animals↗
PubMed1989

Determination of pyridoxal 5'-phosphate in human serum by reversed phase high performance liquid chromatography combined with spectrofluorimetric detection of 4-pyridoxic acid 5'-phosphate as a derivative.

A very sensitive spectrofluorimetric method for the determination of pyridoxal 5'-phosphate (PLP) in human serum is described. The specificity is based on the selective oxidation of PLP to 4-pyridoxic acid 5'-phosphate with potassium cyanide. Separation of the highly fluorescent 4-pyridoxic acid 5'-phosphate is achieved by reversed-phase high-performance liquid chromatography. Specificity is improved by a careful choice of fluorescence filters, maximised at the excitation (325 nm) and emission (418 nm) wavelengths of 4-pyridoxic acid 5'-phosphate. The detection limit for the reaction is 0.22 ng ml(-1). For quantification, the serum is spiked with PLP before protein precipitation with 3.3% m/V trichloroacetic acid. The method can be used for the determination of PLP in serum, even in vitamin B6 deficient patients. The mean value for human serum PLP from 30 healthy adults was found to be 14.6 +/- 4.8 ng ml(-1) (mean +/- standard deviation).

Chromatography, High Pressure Liquid↗
PubMed1989

Magnesium alterations and pharmacokinetic data in gallium-treated lung cancer patients.

The dose of gallium chloride required to inhibit tumor growth after oral and chronic administration depends on the stage of the cancer disease and of the type of metastases. A dose regimen of 800 mg/24 h of gallium chloride will provide serum gallium concentrations greater than or equal to 600 micrograms/l in lung cancer patients with a small and limited disease. A dose of 1,400 mg/24 h is well tolerated in metastatic patients but may not be high enough to reach the desired serum gallium concentrations especially in patients with bone metastases. Radiotherapy and/or a chemotherapy will permit one to increase the serum gallium concentrations and the tumor gallium uptake by reducing the volume of the tumor. After chronic, oral administration of gallium a decrease in RBC Mg is noted. To avoid the Mg deficiency, the treatment must not be interrupted and may perhaps be decreased with care and slowly without resulting in a decrease of the serum gallium concentrations provided the treatment has been prolonged over a sufficient time to enable one to induce intratumor biological modifications and a decrease in the number of the malignant cells. Acute pharmacokinetic data are related to the histologic type of the tumor and may not be used to predict the serum gallium concentrations after chronic administration. The serum gallium concentrations required to inhibit the tumor growth may be higher in small cell lung carcinomas than in nonsmall cell lung carcinomas. Frequent Mg and Ga blood determinations are necessary to manage effective gallium treatment.

Administration, Oral↗
PubMed1989

[Value of determining dexamethasone in the rapid adrenal suppression test].

During the dexamethasone suppression test (DST), we evaluated the relationship between the 8 a.m. dexamethasone (DXM) level and the pharmacokinetics of this corticoid after the oral administration of a single dose at midnight of DXM (1 mg) in 7 healthy subjects. The half-life time of the terminal phase for DXM was 283 min +/- 132 min (mean +/- s.d.). The 8 a.m. DXM level, which is positively correlated with the DXM half-life time, is useful for the interpretation of the DST. On the other hand, no correlation was observed between the 8 a.m. plasma cortisol and DXM levels in 21 healthy subjects. However, the negative correlation between the dose of DXM/kg and post-DXM cortisol level suggests the possibility of adjusting the dose of DXM in obese patients.

Administration, Oral↗