Search PubMed⌕ Search

Biomedical subjects

J B Gouyon

Publications and source records attributed to J B Gouyon.

At least 109 records · Page 6Linked to original sources
PubMed1989

Smectite reduces gastroesophageal reflux in newborn infants.

We assessed the efficacy of a natural clay (smectite) on the frequency and the duration of acid (pH less than 4) and very acid (pH less than 3) gastroesophageal reflux (GER) measured by 24-hour continuous pH recording (CPR). Twenty newborn infants were enrolled in this double-blind controlled study owing to pathological CPR in supine position. After inclusion, all the patients were maintained in the 30-degree elevated prone position and received either smectite (3 g/day; n = 10) or placebo (n = 10) for 7 days. On the 8th day, a second 24-hour CPR was performed in supine position. The postural therapy alone (placebo group) was followed by a significant decrease in the numbers of acid GER (p less than 0.05) during the second CPR. The combination of postural therapy and smectite treatment was followed by a decrease in the number of acid (p less than 0.05) and very acid GER (p = 0.01), the percentages of time spent at pH below 4 (p less than 0.05) and 3 (p less than 0.01) and the maximal duration of acid GER (p less than 0.05).

Clinical Trials as Topic↗
PubMed1989

Adenosine in the immature kidney.

Intrarenal adenosine could be a physiological regulator of glomerular filtration rate and renal blood flow, acting on the renal arteriolar tone. Recent experimental evidence strongly suggests an important role for intrarenal adenosine in the hemodynamic renal changes observed in ischemic acute renal failure (ARF), as well as in various other experimental models of ARF. Adenosine also appears to play a key role in the hypoxemia-induced renal insufficiency in newborn animals. The deleterious functional changes induced by hypoxemia can be prevented by low-dose theophylline, a xanthine with strong adenosine antagonistic properties. The overall experimental data suggest that adenosine vasodilates the efferent glomerular arteriole and vasoconstricts the afferent arteriole when the renin-angiotensin system is stimulated.

Acute Kidney Injury↗
PubMed1989

[Advantages of a single daily dose of sodium valproate in the child].

This study was aimed at testing the efficacy and innocuousness of a single dose of sodium valproate (SV) for the treatment of epilepsy, as compared with 3 daily doses. It was tested on 35 children, 5 to 15 years of age, presenting with the idiopathic form of generalized epilepsy. At the end of one year of treatment with 20 mg/kg/day of SV in 3 daily doses, the children were given a single dose at 8 PM daily. Every 3 months for a period of one year, patients were examined in order to monitor the clinical efficacy and side effects, liver function tests and serum levels of SV at 9 AM and 6 PM. Twenty patients who were well controlled with 3 daily doses had no fits with the single dose treatment. Ten patients, who had had one fit every 6 months during the observation year had no convulsions during the year on a single dose: however, 5 others who had had one fit every 6 months with 3 doses, had fits with the same frequency with the single dose treatment. There were no side effects. SV plasma levels at 9 AM were always higher than those at 6 PM. The efficacy of a single dose may result from the action of SV which increases the intra-cerebral levels of GABA, which are delayed and prolonged.

Adolescent↗
PubMed1989

[Value of rapid diagnostic methods in rotavirus infection in the neonatal period].

One hundred and forty eight faecal specimens were collected from 40 newborn infants during an outbreak of rotavirus infections in a neonatal unit. Rotavirus was sought every 3 days by immunoelectron microscopy (IEM) and was found in 12 newborn babies. Rotavirus excretion persisted for up to 6 days after healing of the diarrhoea. No significant difference was found between infected (n = 12) and uninfected (n = 28) infants with regard to gestational age (35.2 +/- 3.7 vs 36.9 +/- 2.6 weeks), birth weight (2,064 +/- 693 vs 2,197 +/- 529 g), and postnatal ages at the time of the outbreak. The 148 stool specimens were analysed by IEM considered the reference technique and compared with two ELISA methods, and three Latex methods. Rotavirus was identified by IEM in 20 stools. Equivocal results were observed with Slidex Rotakit Polyclonal (16.9%), Slidex Rotakit Monoclonal (2.7%) and Rotalex (13.8%). The positive and negative predictive values were respectively 87.5% and 96.9% for the Slidex Rotakit Monoclonal test, 86.7% and 94.7% for the Rotazyme II test, 100% and 95.5% for the ELISA monoclonal test.

Carrier State↗
PubMed1989

[Vasomotor kidney failure in the newborn infant. Physiopathology and treatment].

Prerenal failure (i.e: functional renal insufficiency or vasomotor nephropathy) is the main cause of acute renal failure in the neonate. The renin-angiotensin system and endogenous renal adenosine intervene in the pathophysiological mechanisms of functional renal insufficiency. Mechanical ventilation, indomethacin and tolazoline may favor or worsen vasomotor nephropathies. Prerenal failure is treated by 1) correction of hypovolemia, systemic hypotension, hypoxemia and acidosis; 2) administration of furosemide and of low doses of dopamine.

Acute Kidney Injury↗
PubMed1988

Renal effects of low-dose aminophylline and enprofylline in newborn rabbits.

Renal function was studied in 15 newborn New Zealand rabbits administered either 0.6 mg/kg enprofylline intravenously. Each animal acted as its own control. Glomerular filtration rate (GFR) and renal blood flow (RBF) were assessed by the clearances of inulin and para-aminohippuric acid, respectively. Enprofylline, a xanthine with low adenosine antagonistic properties, did not modify urine flow rate, GFR, RBF, renal vascular resistance, filtration fraction, sodium and potassium urinary excretion, whereas administration of theophylline, a potent adenosine antagonist, was associated with a significant increase in diuresis, renal vascular resistance and filtration fraction. The differences observed in the renal effects of theophylline and enprofylline strongly support the view that 1) the renal actions of micromolar concentrations of theophylline are mediated by an antagonism with endogenous renal adenosine; 2) renal adenosine could play a physiological role in the regulation of renal hemodynamics.

Aminophylline↗
PubMed1988

Theophylline prevents the hypoxemia-induced renal hemodynamic changes in rabbits.

The acute renal effects of hypoxemia and the ability of theophylline to prevent these effects were assessed in anesthetized and mechanically-ventilated newborn and adult rabbits. Renal blood flow (RBF) and glomerular filtration rate (GFR) were determined by the clearance of para-aminohippuric acid and inulin, respectively. Each animal acted as his own control. In 14 newborn rabbits (group 1), hypoxemia was significantly associated with a fall in GFR (-22 +/- 6%) and filtration fraction (-17 +/- 3%) and with an increase in renal vascular resistance (+13 +/- 6%). Hypoxemia also induced a significant decline in GFR (-27 +/- 6%) and RBF (-29 +/- 6%) in 7 adult rabbits (group 3). Intravenous theophylline (0.5 mg/kg) completely prevented the hypoxemia-induced changes in GFR, filtration fraction (FF) and renal vascular resistance (RVR) in 8 newborn rabbits (group 2). An intravenous dose of 2.4 mg theophylline given after the induction of hypoxemia partially reversed the drop in GFR in adult rabbits (group 3). Separate renal functions were studied in 8 additional adult rabbits (group 4). Low-dose theophylline (27 micrograms/min) infused intra-arterially in the left kidney partially prevented the hypoxemia-induced decline in urine flow rate, GFR, RBF, FF as well as the increase in renal vascular resistance. The beneficial effects of theophylline could be mediated by its adenosine antagonistic properties.

Adenosine↗
PubMed1988

Functional renal insufficiency: role of adenosine.

Adenosine, a direct degradative product of 5'AMP, could be a physiological regulator of glomerular filtration rate and renal blood flow, acting on the renal arteriolar tone and the tubuloglomerular feedback mechanism. Recent experimental evidence strongly suggests an important role for intrarenal adenosine in the hemodynamic renal changes observed in postocclusive acute renal failure, in hypoxemia-induced renal insufficiency, as well as in various experimental models of acute renal failure. In these conditions, adenosine appears to induce predominant postglomerular vasodilatation, as well as preglomerular vasoconstriction when the renin-angiotensin system is activated. Theophylline, a xanthine with strong adenosine antagonistic properties, prevents the hypoxemia-induced renal changes, while enprofylline, a xanthine devoid of such properties, does not prevent these changes. Available data favor the hypothesis that intrarenal adenosine is involved in the pathophysiology of the renal changes observed in the early phase of vasomotor nephropathy.

Acute Kidney Injury↗
PubMed1988

Adverse effects of drugs on the immature kidney.

The immature kidney may be adversely affected by a variety of vasoactive or diuretic drugs, either administered to the mother during pregnancy, or to the neonate. Inhibitors of the angiotensin-converting enzyme administered to the hypertensive pregnant woman can severely and sometimes definitely impair renal function in the fetus, leading to postnatal anuria. Pathogenesis involves interference with the renin-angiotensin system and the prostaglandins. Beta-adrenergic agents administered during labor depress glomerular filtration rate transiently. Tolazoline, an alpha-adrenergic blocking agent useful in the treatment of persistent pulmonary hypertension of the neonate induces intense renal vasoconstriction with consequent hypoperfusion. Indomethacin, a prostaglandin synthetase inhibitor used for the pharmacological closure of a patent ductus arteriosus, also increases renal vascular resistance, and decreases urine output. Furosemide, the drug most often used in oliguric neonates, may also adversely affect the newborn infant. Its use has been associated with an increase in the incidence of patent ductus arteriosus, hypercalciuria, nephrocalcinosis and secondary hyperparathyroidism. These observations demonstrate that the proper use of drugs requires that the therapeutic endpoint be clearly defined and the predictable side effects be anticipated.

Adrenergic beta-Agonists↗
PubMed1988

Renal effects of d-tubocurarine and pancuronium in the newborn rabbit.

The acute renal effects of d-tubocurarine and pancuronium were assessed in 14 anesthetized newborn rabbits. Glomerular filtration rate (GFR) and renal blood flow (RBF) were calculated from the inulin and p-aminohippuric acid clearances, respectively. Each animal acted as its own control. At doses used in human neonates, d-tubocurarine administration (0.80 mg/kg) produced a marked increase in renal vascular resistance (+123 +/- 62%) with a concomitant significant decrease in GFR (-35.4 +/- 12%) and RBF (-39 +/- 13%). Pancuronium administration (0.25 mg/kg) was associated with a nonsignificant decrease in GFR (-19 +/- 17%) and RBF (-20 +/- 12%) and an increase in renal vascular resistance (+66 +/- 52%). These results stress the need for careful monitoring of renal function in neonates receiving nondepolarizing muscle-relaxant agents.

Animals↗
PubMed1988

Body fluid homeostasis in the newborn infant with congestive heart failure: effects of diuretics.

Congestive heart failure is characterized by extracellular fluid volume expansion, increased venous filling pressure, and paradoxal renal sodium retention. Although diuretics remain invaluable agents to lower venous pressure in congestive heart failure, they also carry the risk of further compromising cardiac output and inducing severe adverse effects. This article reviews the pathophysiology of body fluid homeostasis in neonates with congestive heart failure, and discusses the adverse effects associated with the use and abuse of diuretics.

Body Fluids↗
PubMed1988

[Esophageal pH-monitoring in asymptomatic and symptomatic newborn infants].

The supine distal esophageal pH was recorded over 24 hours, in low birth weight infants. Forty-seven of them were asymptomatic (group T) and 93 presented with digestive symptoms (regurgitations and/or vomiting) associated (group DA; n = 49) or not (group D; n = 44) with a history of apneas, bradycardias, cyanosis or pallor fits. On the recording day, post-natal ages (weeks), conceptional ages (weeks) and weights (g) were not different among the 3 groups (T: 4.8 +/- 2.6; 40.1 +/- 2; 2,590 +/- 210. DA: 4.7 +/- 3.3; 40 +/- 3.3; 2,980 +/- 640. D: 4.7 +/- 2.8; 41.1 +/- 3.3; 2,710 +/- 620). In the 3 groups all the features of the acid and highly acid gastroesophageal refluxes (GER) were significantly more marked in late post-prandial stages (LPPS) than in early post-prandial stages (EPPS) (p less than 0.001). Slightly acid GER were more frequent in LPPS than in EPPS for groups T and DA (p less than 0.01). No significant difference could be found when comparing group T with groups D, DA and with a sample of 21 infants presenting with vomiting.

Apnea↗
PubMed1987

The newborn rabbit: a model for studying hypoxemia-induced renal changes.

The newborn rabbit was used as an experimental model for studying renal changes during normocapnic hypoxemia. Renal extraction of p-aminohippuric acid (PAH), as assessed in 15 normoxemic and 8 hypoxemic rabbits amounted to 54.6 +/- 3.7 and 45.7 +/- 4.6%, respectively (NS). Changes in glomerular filtration rate (GFR), and renal blood flow (RBF) as assessed by inulin and PAH clearances, respectively, were determined during normoxemia and subsequent hypoxemia in 8 additional anesthetized and mechanically ventilated newborn rabbits. Normocapnic hypoxemia (PaO2 = 38.6 +/- 2.1 mm Hg) induced a significant fall in GFR from 2.10 +/- 0.21 to 1.51 +/- 0.18 ml/kg/min (p less than 0.01), in filtration fraction (p less than 0.01) and U/P inulin ratio (p less than 0.01). RBF, renal vascular resistance and urine flow rate did not change significantly. In comparison with other immature animal species the newborn rabbit appears a valuable and inexpensive model for the study of acute hypoxemia-induced renal changes.

Animals↗
PubMed1987

Urinary excretion of N-acetyl-glucosaminidase and beta-2-microglobulin as early markers of gentamicin nephrotoxicity in neonates.

A prospective study in 16 healthy and 16 gentamicin-treated neonates was undertaken to compare the urinary excretion of proximal tubular markers such as beta 2-microglobulin (beta 2-m) and total N-acetyl-beta-D-glucosaminidase (NAG) and its isoenzymatic form NAGB. beta 2-m excretion was not related to postnatal age in control full-term neonates; it was significantly increased in gentamicin-treated full-term neonates. The urinary excretion of the lysosomal markers, total NAG and NAGB, rose significantly with postnatal age in control group. fMean values for total NAG and NAGB were significantly higher in the treated group but the isoenzymatic profile (NAGB/total NAG X 100) was not modified by gentamicin treatment.

Acetylglucosaminidase↗