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Biomedical subjects

C Jacquot

Publications and source records attributed to C Jacquot.

At least 145 records · Page 8Linked to original sources

Dopaminergic metabolism in various rat brain areas after L-dopa loading.

The time course of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3-methoxytyramine (3-MT) and 3-methoxytyrosine (3-O-Medopa) concentrations in rat brain after treatment with L-dopa + benserazide has been investigated in the striatum, hypothalamus, hippocampus and cerebellum. These areas were selected for their different dopaminergic activities. After L-dopa loading, DA, DOPAC and HVA were increased in all the structures, but the largest increases were in those tissues with the less dopaminergic activity, while 3-MT increased in the hypothalamus, hippocampus and cerebellum but was lowered in striatum. 3-O-Medopa, which is the direct product of the O-methylation of L-dopa, did not show any specific distribution. The data provide evidence that the striatum, by feed-back mechanisms and specific enzymatic activity, is able to ensure a better regulation of dopaminergic activity than the other structures, thereby overcoming excess L-dopa.

3,4-Dihydroxyphenylacetic Acid↗

Re-evaluation of the L-dopa loading effect on dopamine metabolism in rat striatum.

Investigation by HPLC with electrochemical detection of dopamine (DA) metabolism in rat striatum after L-dopa + benserazide treatment allowed quantification of the time course evolution of DA, 3,4-dihydroxyphenylacetic acid and homovanillic acid levels. Furthermore, four peaks which did not appear in controls, were detected in treated striatum. One was identified as 3-methoxytyrosine, the level of which was still high 9 h after treatment. 3-Methoxytyrosine, has been detected previously in plasma of parkinsonian patients treated with L-dopa, and the disturbance in DA metabolism could explain some of the side-effects induced by that treatment.

3,4-Dihydroxyphenylacetic Acid↗

De novo focal glomerular sclerosis in preeclampsia.

Eleven women were selected on the presence, in postpartum renal biopsies, of focal glomerulosclerosis (FGS) superimposed to glomerular lesions of typical pregnancy-induced nephropathy. Ten out of them presented with severe preeclampsia. The renal specimens were examined by light and/or electron and/or immunofluorescence microscopy. The present study gathered clinical and morphological data suggesting that FGS might develop during preeclampsia. In these renal biopsies with FGS and lesions of pregnancy-induced nephropathy a sparse detachment of podocyte was observed at a distance from the segmental lesions by electron microscopy. The latter has also been observed in experimental models of FGS in which FGS is dependent on glomerular hemodynamic alterations. We think that the mechanism of the development of FGS in these pathological pregnancies may be analogous to these experimental models of FGS with hyperfiltration.

Adolescent↗

Pharmacokinetics of pefloxacin in renal insufficiency.

The kinetics of pefloxacin has been studied after a single intravenous infusion of 8 mg X kg-1 in 15 male patients with various degrees of renal failure. No difference in distribution or elimination of the drug was observed between patients with mild or severe renal impairment. The mean volume of distribution (Vd area) and the mean plasma clearance were 2.03 l X kg-1 and 121.3 ml X min-1, respectively. The mean apparent elimination half-life was 13.5 h. These values are close to those observed in healthy subjects. No accumulation of the active N-desmethylmetabolite was observed in cases of severe failure as compared to mild impairment; its apparent elimination half-life was about twice that of the parent drug. The efficacy of a 4 haemodialysis in 6 additional anuric subjects done to remove pefloxacin from the body was poor.

Adult↗

Association light chain deposition disease (LCDD) and amyloidosis. One case.

Up to now, light chain deposition disease (L.C.D.D.) and amyloidosis have been shown to occur in different individuals. A case of association is described in a 76 year old man with terminal renal failure and normal size kidneys. Percutaneous renal biopsy showed glomerular and peritubular fixation of labeled antikappa light chain serum. Stains for amyloidosis were positive in small vessels. Kappa free chains were found in both serum and urine and the bone marrow showed predominantly kappa-containing plasma cells. By electron microscopy both electron-dense granular deposits and amyloid like fibrils were found in the wall of arterioles and small arteries.

Aged↗

Metabolism of 6,7-dimethoxy 4-(p-chlorobenzyl)-isoquinoline. I. Single-dose pharmacokinetics in the rat and mouse.

The pharmacokinetics of 6,7-dimethoxy 4-(p-chlorobenzyl) isoquinoline (PV 2) in mouse and rat show that it is 52% absorbed after oral administration and undergoes a marked hepatic first-pass effect (83%). Tissue distribution shows an affinity for the aorta, cardiac tissues and cerebral blood vessels. It is excreted in the urine (20% dose) and faeces (70%); biliary excretion is high (80% dose). It is metabolized mainly by O-demethylation to 6- and 7-desmethyl-PV 2 and 6,7-didesmethyl-PV 2, as well as to six other non-identified metabolites.

Animals↗

Association of systemic light-chain deposition disease and amyloidosis: a report of three patients with renal involvement.

Three patients with renal involvement, plasma cell dyscrasia and systemic light chain deposition are reported in whom well characterized amyloid deposits were also found in the vessel walls. This association, not yet reported, is probably more frequent than believed and still brings nearer these two manifestations of monoclonal light chain deposition. Whether or not the finding of amyloid deposits during systemic light chain deposition is a separate entity and modifies the prognosis remains to be answered.

Adult↗

Evidence for an activating effect of tabernanthine on rat brain catecholamine synthesis and elimination.

Tabernanthine increased the synthesis and elimination of catecholamines (CA) in the striatum and the rest of the brain, but not in the hypothalamus. These data provide evidence that tabernanthine may activate CA turnover of some brain structures by acting at 2 steps of the metabolic pathway. The results are discussed in relation to a central stimulating action and a hypoxia antagonistic effect of this drug.

Alkaloids↗

Evidence for an antagonistic action of tabernanthine on hypoxia-induced changes in brain serotonin levels.

The effects of tabernanthine on serotonin (5-HT) levels were determined in several brain areas of rats exposed to various simulated altitudes (1800, 5200, 7000 m). The 5-HT synthesis inhibitor, para-chlorophenylalanine (PCPA), was used to dissociate the effects occurring at synthesis and release levels. Tabernanthine antagonized the decrease in hypothalamic 5-HT levels induced by a 7000 m hypoxia and also suppressed the decrease in PCPA-induced depletion observed at 5200 and 7000 m in the hypothalamus, the striatum and the rest of the brain. It was assumed that tabernanthine stimulates different steps of 5-HT metabolism. These effects, revealed by hypoxia, are related to other peripheral and central properties of this drug.

Alkaloids↗

Pharmacokinetic study of digoxin-benzamide interaction in the rat.

Simultaneous oral administration of digoxin and three benzamides (Metoclopramide, Alizapride, Bromopride) to the rat, modify digoxin's pharmacokinetic parameters: peak plasma concentration, elimination phase half life and bioavailability (Bromopride, Alizapride in function with dose-level). Our conclusion, is that drug-monitoring is necessary for this drug association.

Administration, Oral↗

Fenfluramine and brain transmitters in the obese Zucker rat.

Genetically obese Zucker rats and their lean litter mates were treated for 5 days with fenfluramine. Levels of noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5-HT) and gamma-aminobutyric acid (GABA) and their metabolism were assayed in the hypothalamus, striatum, medulla-oblongata pons and remainder of the brain. Fenfluramine induced a slight increase in the level of NE in the hypothalamus in lean rats and a marked decrease in obese rats. No change in the synthesis of NE was found. Fenfluramine had no effect on the level and metabolism of DA. The levels of 5-HT were decreased by fenfluramine in obese and lean rats, and the metabolism was increased. The levels of GABA were not changed by fenfluramine. Synthesis of GABA was increased in the remainder of the brain of obese and lean rats. These data suggest that fenfluramine acts on 5-HT systems in both obese and lean rats and are consistent with reports of the pharmacological effects of fenfluramine.

Animals↗

[Pollution of operating rooms with volatile and gas anesthetics. Methods of prevention].

Gaseous anaesthetic pollution in operating theatres has been known since as far back as 1924. Following Vaisman and Cohen's epidemiology studies, health organizations have been involved in this professional concern. Halogenated vapours and nitrous oxide anaesthetic pollution have been accused of doubling the abortion rate and of moderately increasing the number of congenital abnormalities in the offsprings of anaesthetists. The liver and nervous system are also likely targets for anaesthetic pollution. Animal or cell culture experimental studies concerning pathological consequences of exposure to nitrous oxide or halogenated vapours give conflicting results and are not conclusive. The pollution rate is measured by chromatography and spectrophotometry. 25 ppm nitrous oxide and 2 ppm halothane are the upper limits allowed for air contamination. Total intravenous anaesthesia, closed circuits, draining away expired gases can prevent such pollution, but these techniques do have drawbacks. Pollution prevention is rather simple, moderately expensive and comforting for operating room staff.

Air Pollution↗

[Anuria caused by perianeurysmal retroperitoneal fibrosis. Medical treatment. A case report].

After 3 sessions of haemodialysis, renal function returned to normal, but the bilateral ureteral obstruction recurred 11 months later with signs of compression of the inferior vena cava. Corticosteroid therapy in doses of 0.5 mg/kg/day resulted in disappearance of the pyeloureteral dilatation at intravenous urography and regression of the fibrosis on CT sections. From a review of the literature the authors describe the clinical symptoms, diagnostic methods and main treatments of perianeurysmal retroperitoneal fibrosis, a not uncommon disease.

Aged↗

Effect of three anorectic drugs on brain GABA levels and synthesis in the Zucker rat.

1. Genetically obese Zucker rats and their lean littermates were submitted to a subchronic treatment with fenfluramine, mazindol and amphetamine. GABA levels and synthesis index were measured in different brain areas. 2. GABA levels, similar in obese and lean controls, were not changed after the three treatments. 3. A higher synthesis index of GABA was found in lean rats, in the striatum after mazindol and in the hypothalamus after amphetamine. 4. The three drugs increased the synthesis index of GABA in the remainder of the brain of both obese and lean rats.

Animals↗

Effect of three anorectic drugs on central catecholamine levels and synthesis in the Zucker rat.

1. Genetically obese Zucker rats and their lean littermates were treated during 5 days with fenfluramine, mazindol or amphetamine. Norepinephrine and dopamine levels were assayed in the hypothalamus, striatum, medulla-oblongata pons and remainder of the brain, and the amine synthesis was estimated, when possible. 2. Fenfluramine acted especially on norepinephrine in the obese rat hypothalamus. 3. Mazindol was active on norepinephrine and dopamine levels only in obese animals. 4. Amphetamine acted on norepinephrine levels only in obese rats and on dopamine levels in both obese and lean rats.

Animals↗

[Pharmacokinetics of gentamicin in the decompensed alcoholic cirrhotic patient. Therapeutic consequences].

Aminoglycosides and in particular gentamicin are still largely used in the treatment of spontaneous bacterial peritonitis in the decompensed alcoholic cirrhotic patient. For that matter, we decided to study the various passage of gentamicin in the ascites after its administration through IM injection (80 mg in 6 patients and 120 mg in 6 other patients) and through IV injection (120 mg in 6 other patients). What could possibly be the best protocol to replace the daily intraperitoneal injections? We found out that no matter what the style of injection is, the peritoneal levels are only exceptionnaly higher than 3 mg/g at the highest peak period. These results brought us to analyze the passage of gentamicin in the blood when injected intraperitonealy (160 mg in 6 patients), and then to propose a therapeutic protocol combining on the first day, to the peritoneal injection a loading dose of an IP injection of 160 mg, the relay been taken over later with a peritoneal injection of 80 or 120 mg repeated 2 or 3 times daily. For each of the protocol the pharmacokinetic coefficients of gentamicin were calculated.

Bacterial Infections↗