Search PubMed⌕ Search

Biomedical subjects

P Larose

Publications and source records attributed to P Larose.

12 recordsLinked to original sources
PubMed1992

Effect of lignocaine on arginine-vasopressin plasma levels: baseline or induced by frusemide.

1. To assess whether or not lignocaine influences baseline and frusemide-induced (5 mg kg-1) plasma concentrations of arginine-vasopressin (AVP), 2 groups of rabbits received an infusion of lignocaine (130 micrograms min-1 kg-1) for 6 h. Lignocaine-induced changes in AVP plasma concentrations were substantiated by measurement of diuresis and natriuresis and hepatic plasma flow, by means of an infusion of indocyanine green (ICG) (249 micrograms min-1 kg-1). 2. Baseline plasma AVP levels were 4.9 +/- 0.9 pg ml-1 (+/- s.e.), and following lignocaine, these values were reduced to 0.7 +/- 0.1 pg ml-1 (P less than 0.01). Frusemide increased AVP levels to 134.1 +/- 73.6 pg ml-1 (P less than 0.05) and lignocaine totally prevented this increase, e.g. mean AVP levels of 2.7 pg ml-1. 3. Lignocaine enhanced baseline diuresis secondary to an increase in free water clearance; none of the experimental conditions affected the diuresis and natriuresis induced by frusemide. 4. Frusemide reduced the hepatic plasma flow and this decrease was not reversed by the infusion of lignocaine. 5. It is concluded that in healthy rabbits lignocaine reduces baseline secretion of AVP and its antidiuretic effect; in addition, lignocaine prevents the rise in AVP induced by frusemide.

Animals↗
PubMed1991

Furosemide dynamics: influence of dietary sodium and of saralasin.

The influence of dietary sodium and saralasin on the natriuretic and diuretic response to furosemide (5 mg/kg i.v.) was studied in three groups of conscious rabbits maintained for 4 weeks on either a normal sodium diet (NSD), or a low sodium diet (LSD) or a high sodium diet (HSD). Neither the sodium content in the diet nor saralasin affected glomerular filtration rate or renal plasma flow. Compared to the NSD, an LSD did not affect the furosemide-induced increment in urinary excretion of sodium (dUNaV) but increased the increment in urinary excretion (dUV) (p less than 0.05). An HSD reduced the furosemide-induced dUNaV and dUV (p less than 0.05). Plasma renin activity (PRA) increased following furosemide administration in animals on an NSD and an LSD, but not in those on an HSD. Independent of diet, a positive correlation occurred between the increment in PRA and the dUNaV (p less than 0.001). Saralasin increased PRA and decreased baseline urinary excretion of sodium (UNaV). In addition, in rabbits on an LSD, saralasin reduced the furosemide-induced dUNaV and dUV by 34 and 27% (p less than 0.05), respectively. It is concluded that furosemide-induced diuresis is increased in rabbits on an LSD and decreased in rabbits on an HSD. In animals on an LSD, the increase in furosemide response appears to be associated with changes in the activity of the renin-angiotensin system and in rabbits on an HSD, the decrease in furosemide effect is probably the net result of several factors.

Animals↗
PubMed1991

Biocompatibility.

Explore the source record for details and available documents.

Dental Amalgam↗
PubMed1990

Nosocomial Serratia marcescens individualized by five typing methods in a regional hospital.

The relationships between 69 isolates obtained from 26 patients who were affected by two Serratia marcescens hospital outbreaks occurring in the urology and postnatal wards, were examined by five typing methods for epidemiological purposes. Serotyping, antibiotic resistance profile and electrophoretic analysis of enzymes identified three groups of isolates, while biotyping and bacteriocin typing identified only two. These surveys allowed us to demonstrate the existence of independent episodes of cross-infection among patients of each ward.

Bacterial Typing Techniques↗
PubMed1990

[Comparative activity of new oral cephalosporins and quinolones against Escherichia coli resistant to ampicillin isolated from urinary specimens].

The activity of eight antibiotics was studied against fifty Escherichia coli strains resistant to ampicilline from positive urine cultures. We compared the in vitro activity and the inhibitory power of urine. Three antimicrobial agents are the most active: pefloxacin, ofloxacin and cefotaxime. Then in activity order: pipemidic acid, cefixime, cefuroxime, amoxicilline-clavulanic acid and cefalotine.

Ampicillin Resistance↗
PubMed1989

[Q fever infectious endocarditis. Apropos of a new case].

We report a case of Coxiella burnetii endocarditis in a 42-year old man presenting with a long-known cardiac murmur and an infectious syndrome of several months duration. The aetiological diagnosis, delayed by the lack of knowledge of a primary Q fever, was established by serology. The infection responded to tetracycline combined with cotrimoxazole, but a valve replacement performed for haemodynamic reasons was followed by serious complications. We remind the readers that Q fever endocarditis must be considered as a possible diagnosis in all cases of endocarditis with negative blood cultures and that specific serological examinations in search of anti-phase I antibodies of the IgA type should be performed as soon as possible, using the indirect immunofluorescence technique. Attention is drawn to the different serological responses of the three clinical types of Q fever infection and to the cellular immunity associated with that disease.

Adult↗
PubMed1988

Characterization of the effect of nicotine on vasopressin and atrial natriuretic factor in the rabbit.

The effects of nicotine on the secretion of arginine vasopressin (AVP) and of the atrial natriuretic factor (ANF) were examined in conscious rabbits. Nicotine was shown to produce significant increases in plasma AVP from 1.7 +/- 0.4 to 75.3 +/- 35.1 pg/ml (P less than .05) and in plasma ANF levels from 39 +/- 11 to 121 +/- 52 pg/ml (P less than .05) within 5 min of an i.v. dose of 0.5 mg/kg. These nicotine-induced stimulations could not be inhibited by muscarinic (atropine), dopaminergic [(+/-)-sulpiride], alpha (phenoxy-benzamine) or beta adrenergic (propranolol) blockers or by a rapid infusion of fluids. Trimetaphan was ineffective in blocking the stimulation of AVP secretion but completely abolished the nicotine-induced secretion of ANF. The more lipophilic ganglionic blocker, mecamylamine, blocked the stimulation of the secretion of both peptides. The effect of nicotine on AVP production was confirmed in vitro using the rat hypothalamo-neurohypophysial system preparation where nicotine increased AVP secretion in a dose-dependent manner. This in vitro stimulation was blocked by the ganglionic blocker hexamethonium. The increase in ANF plasma concentrations was probably due to a primary response to nicotine, for although exogenous AVP (1 microgram i.v.) increased ANF levels by a factor of 3 (P less than .05), the AVP antagonist [-(beta-mercapto-beta,beta-cyclopentamethylenepropionic acid)-2- (O-methyl)tyrosine]arginine vasopressin did not prevent the nicotine-induced increase in ANF. Thus, nicotine or its effects appear to stimulate the secretion of ANF and not AVP. It was concluded that nicotine stimulates the secretion of AVP by activating central nicotinic projections to the hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Effect of moderate hypoxemia on atrial natriuretic factor and arginine vasopressin in normal man.

The object of this study was to assess the effect of moderate acute hypoxemia on plasma concentrations of atrial natriuretic factor (ANF), arginine vasopressin (AVP), plasma renin activity (PRA) and urinary excretion of prostaglandin E2 (UPGE2V). Eight volunteers were exposed for 2 hours to a gas mixture containing 10% O2, 4.5% CO2 and 85.5% N2. Hypoxia increased diastolic blood pressure and free water clearance. Hypoxia did not change the AVP, PRA or UPG2V, although increased ANF from 17.7 +/- 3.4 pg/mL to 27.2 +/- 1.7 pg/mL (p less than 0.005) at 120 minutes. ANF changes were closely associated with the rise in blood pressure.

Adult↗
PubMed1987

The effect of cyclophosphamide on arginine vasopressin and the atrial natriuretic factor.

The effect of cyclophosphamide (CTX) on the renal handling of water and sodium and on plasma concentrations of vasopressin (AVP) and of the atrial natriuretic factor (ANF) was studied in the rabbit. When compared to controls, animals receiving CTX (100 mg/kg IV) showed an increase in the diuresis and natriuresis. In addition, ANF plasma concentrations increased by 84% between 4 and 8 hours after CTX, while AVP plasma concentrations remained unchanged. It is concluded that in the rabbit CTX has a diuretic and a natriuretic effect that may, at least in part, be related to the increase in ANF plasma concentrations.

Animals↗
PubMed1985

Radioimmunoassay of atrial natriuretic factor: human plasma levels.

A simple and sensitive radioimmunoassay procedure has been developed for the determination of atrial natriuretic factor (ANF) in human plasma. The rabbit antiserum was obtained from a commercial source. ANF was extracted from plasma using an octadecasilyl silica cartridge with a recovery of 78.7%. HPLC of the plasma extract showed the presence of one immunoreactive peak of ANF corresponding to its low molecular weight form. Plasma ANF in humans increased from 8.0 +/- 2.2 in upright position to 20.0 +/- 5.9 fmol/ml (n = 6) in downward position (p less than 0.005).

Animals↗
PubMedDate not supplied

Effect of atrial natriuretic factor on plasma vasopressin in conscious rats.

An intravenous (IV) bolus injection (10 micrograms) of synthetic rat atrial natriuretic factor [ANF (Arg 101-Tyr 126)] into normal conscious Sprague-Dawley rats produced a significant decrease of plasma arginine vasopressin (AVP) while 1-, 2- and 5-micrograms doses exerted no such effect. Mean arterial blood pressure (MAP) was lowered about 15 mmHg by an IV 10 micrograms bolus injection of ANF. When plasma AVP rose significantly in rats exposed to such osmotic stimuli as 600 mM NaCl and 900 mM mannitol intraperitoneally (IP), subsequent IV injection of ANF (10 micrograms) markedly depressed this parameter. Lower doses of ANF were ineffective against 600 mM NaCl IP. The significant elevation of plasma AVP levels by hypertonic sucrose 900 mM IP was not modified by ANF (10 micrograms). Blood pressure remained unchanged after IP administration of various osmotic stimuli, except mannitol, and in all these experiments an IV bolus of ANF exerted a lowering effect on MAP. Seventy-two hr water deprivation (mixed osmotic and volume stimulus) resulted in elevated plasma AVP levels which were unaffected by an IV bolus injection of ANF at doses of 0.06-10 micrograms. Immunoreactive ANF (IR-ANF) rose in plasma to 39.3 +/- 13 ng/ml 1 min after an IV bolus injection of 10 micrograms ANF, dropping to 1.01 +/- 0.2 ng/ml after 5 min and to 0.32 +/- 0.01 ng/ml after 10 min (when ANF and AVP interactions were studied), but still remained approximately six times higher than in control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗