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Biomedical subjects

B Vailly

Publications and source records attributed to B Vailly.

13 recordsLinked to original sources

[Electric short-circuit incident observed with "Upsher" laryngoscopes].

We observed an electrical short-circuit between a fasten screw of the printed circuit and the handle of an Upsher universal laryngoscope (serial number UQ1). The isolating Silicone layer was broken above the screw. This isolation defect was found all over our Upsher laryngoscopes of the UQ1 series. No doubt that if accumulators were used instead of batteries, emitted heat would be in largest amount and perhaps dangerous.

Electricity↗

[Digestive surgery and varicose vein surgery].

The thromboembolic risk related to surgery may be considered as low for varicose vein surgery and non major digestive surgery. It could be defined as moderate in case of large dissection, long duration of procedures and emergency cases. The risk may be considered as high for major abdominal surgery involving cancer surgery or not and bariatric surgery. The absence of prophylaxis can be proposed for low risk surgery (grade B). However, elastic compression stocking are effective for all cases of digestive surgery and suggested to be used (grade A). There are no data concerning the moderate risk situation. Therefore, experts recommend the use of elastic compression stockings or low doses of LMWH (grade D). High-risk surgery requires the use of high doses of LMWH recommended for reasons of efficacy, tolerance, and easiness to use (grade A). Associated elastic stockings is efficious (grade B). The duration of prophylaxis lasts generally 7-10 days. Extension to 1 month is recommended for major abdominal cancer surgery (grade A).

Ambulatory Surgical Procedures↗

Effects of dopamine prodrugs and fenoldopam on glomerular hyperfiltration in streptozotocin-induced diabetes in rats.

The effects of dopamine (DA) prodrugs (L-dopa and gludopa) and of a D1-selective agonist (fenoldopam) on glomerular hyperfiltration were studied in the early stage of diabetes in rats. Wistar rats received one injection of streptozotocin (STZ) and were treated 1 week later with L-dopa (2 x 10 mg/kg/day, s.c.), gludopa (2 x 3 or 2 x 10 mg/kg/day, s.c.), or fenoldopam (2 x 0.3 or 2 x 1 mg/kg/day, s.c.). Their renal functions were compared with those of untreated diabetic and nondiabetic control rats. STZ injection led to hyperglycemia that was kept moderate (20-25 mmol/L) by daily insulin therapy (2-4 U of NPH insulin). Within 2 weeks, glomerular hyperfiltration (polyfructosan clearance) developed in diabetic rats (30% increase vs. nondiabetic control). A rise in renal plasma flow (PAH clearance) was sometimes observed. One week of treatment with either L-dopa, gludopa, or fenoldopam normalized the glomerular filtration rate and decreased filtration fraction. These corrections occurred despite similar metabolic disturbance and kidney hypertrophy. Gludopa was less well tolerated by diabetic rats than L-dopa. Results with L-dopa showed that the normalization of glomerular hyperfiltration was linked to DA synthesis and stimulation of D1 receptors, since it was reversed by carbidopa, a dopa decarboxylase inhibitor, and by SCH 23390, a D1-selective antagonist. These data show that DA prodrugs and a D1 agonist can suppress diabetic glomerular hyperfiltration in the very early course of the disease in rats.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

Renal dopamine synthesis from precursors.

In the Wistar rat in vivo L-dopa (10 mg/kg, subcutaneously) was shown to have the characteristics of a kidney-directed dopamine (DA) prodrug: two daily injections increased 24 h urinary DA excretion 450-fold but had no systemic effects on blood pressure and heart rate. In inactin-anesthesized rats, L-dopa increased natriuresis, diuresis and renal blood flow; these effects were linked to endorenal DA synthesis and to DA-1 receptor stimulation since they were suppressed by both carbidopa and SCH 23390. In the isolated perfused rat kidney, DA was synthesized from L-dopa with a greater yield than from gludopa. In nonfiltering kidneys, L-dopa metabolism was not limited when the access to dopa decarboxylase was restricted to the basolateral membrane. The same was not true for gludopa, for which the basolateral metabolism was low.

Animals↗

L-dopa and streptozotocin-induced diabetic nephropathy in rats.

The purpose of the present study was to determine whether the physiological dopamine prodrug, L-dopa, could suppress streptozotocin-induced diabetic glomerular hyperfiltration, and thus prevent further evolution of the diabetic nephropathy. Male Wistar rats treated with streptozotocin (60 mg/kg, intravenously) rapidly developed hyperglycemia which was stabilized (congruent to 4 g/L) by a daily insulin injection. Within two weeks, a significant increase in glomerular filtration rate (GFR) and a rise in the filtration fraction were observed as described in the early stage of diabetic nephropathy. Increase in both GFR and in the filtration fraction were normalized by treating the rats with L-dopa (10 mg/kg, subcutaneously, twice a day for one week). The effects of L-dopa were linked to endorenal DA synthesis and to DA-1 receptor stimulation since both carbidopa and SCH 23390 suppressed them.

Animals↗

[Prevention by L-dopa of early renal consequences of diabetes induced by streptozocin in rats].

The early renal effects associated with streptozotocin-induced diabetes in rats (glomerular hyperfiltration and increase in filtration fraction) are similar to modifications reported in the early stage of human diabetic nephropathy. We examined the reversibility of these early renal diabetic effects by dopamine, which might correct glomerular hyperfiltration thanks to its preferential vasodilatory action on glomerular efferent arterioles. A dopamine prodrug, L-dopa was used to increase endorenal dopamine synthesis. Studies were carried out on streptozotocin-treated (60 mg/kg, i.v.) Wistar rats, supplemented with NPH insulin (2 to 3 U/day) such as to stabilize hyperglycemia at 22 mmol/l. One week after diabetes induction, animals were treated during a week either with L-dopa (10 mg/kg, s.c. twice daily) or L-dopa plus a dopa-decarboxylase inhibitor, carbidopa (10 mg/kg, s.c. 30 min before each L-dopa injection) or L-dopa plus a selective D1 receptor antagonist, SCH 23390 (100 micrograms/kg, s.c., with each L-dopa injection). Control diabetic animals received the solvent of L-dopa and control non-diabetic animals received the solvent of streptozotocin. After one week of L-dopa or other treatment, the renal functions of the rats were investigated (polyfructosan and PAH clearances) under inactin anaesthesia. As expected, streptozotocin induced glomerular hyperfiltration (1.3 +/- 0.07, n = 14, versus 0.93 +/- 0.05 ml/min.g kidney weight in non-diabetic controls, p less than 0.001) and an increase in filtration fraction (52.4 +/- 5.1 versus 32.1 +/- 1.7%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Hepatic mono-oxygenases].

Most drugs and xenobiotics are lipid-soluble compounds that need to be transformed into more polar water-soluble molecules by a system of hepatic monoxygenases in order to be excreted by the kidney and the liver. This system is also called cytochrome P-450. It is found in animals, as well as plants. It is located in the cellular endoplasmic reticulum of numerous tissues, but it is most active in the liver. It is made up of several isoenzymes differing from one another by the structure of their apoproteins, their immunological characteristics and their affinity for various substrates. Cytochrome P-450 has great variability, being influenced by exogenous factors (drug intake, ionizing radiation, stress, diet) and individual endogenous factors (age, sex, genetic factors). Several non specific tests exploring the system are available. They include: direct investigations carried out on liver biopsies, which are seldom used in clinical practice, and indirect investigations, such as the measurement of the clearance of exogenous substances, of urinary metabolites of endogenous substances and of specific enzymes. Induction and inhibition of microsomal activity are of the utmost interest to the clinician in various fields such as toxicology, carcinogenesis, drug interactions or drug habituation, metabolic regulations and maintenance of body homeostasis. Seven classes of enzyme inducers have been defined, but the exact mechanism of this has only been identified for two of them (the barbiturate and polycyclic hydrocarbon groups). Several drugs have been identified as enzyme inhibitors, the best known to the anaesthesiologist being macrolide antibiotics, imidazole derivatives, cimetidine, chloramphenicol and isonazide.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminoglycosides↗

[Cardiac failure caused by an overdose of dantrolene].

A case is reported of cardiac failure with repeated pulmonary oedema in a female patient suffering from renal failure and having been given incremental doses of dantrolene sodium. On withdrawal of the drug, all symptoms disappeared. This muscle relaxant was considered not to have any depressive myocardial side-effects. However, recent studies on isolated myocardial fibres showed the existence of a constant dose-dependent negative inotropic effect of dantrolene sodium, only noticeable with high concentrations of the drug.

Acute Kidney Injury↗