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Biomedical subjects

R Moreau

Publications and source records attributed to R Moreau.

At least 145 records · Page 8Linked to original sources
PubMed1992

Blockade of ATP-sensitive K+ channels by glibenclamide reduces portal pressure and hyperkinetic circulation in portal hypertensive rats.

Certain results of in vitro studies raise the possibility that blockade of ATP-sensitive K+ channels by glibenclamide may induce vasoconstriction. Therefore, this substance might decrease portal pressure and hyperkinetic circulation in animals with portal hypertension. Thus, systemic and regional hemodynamics (radioactive microspheres) were measured before and 20 min after a bolus intravenous injection of glibenclamide (20 mg/kg) in conscious rats with portal vein stenosis. Blood pressure decreased significantly from 14.5 +/- 1.5 to 12.2 +/- 1.2 (mean +/- SE). Cardiac index significantly decreased by 24%, portal tributary blood flow by 31%, and hepatic artery blood flow by 35%. Systemic vascular resistance significantly increased by 38%, portal territory vascular resistance and hepatic artery vascular resistance by 61%, each, and renal vascular resistance by 17%. Arterial pressure, heart rate, and renal blood flow were unchanged. Moreover, glibenclamide blunted the vasodilating action of diazoxide (an ATP-sensitive K+ channel opener). These results show that in rats with extrahepatic portal hypertension the blockade of ATP-sensitive K+ channels by glibenclamide reduces portal pressure and hyperkinetic circulation.

Adenosine Triphosphate↗
PubMed1992

Septic shock in patients with cirrhosis: hemodynamic and metabolic characteristics and intensive care unit outcome.

OBJECTIVES: To examine the hemodynamic and metabolic characteristics and ICU outcome of septic shock in patients with cirrhosis. DESIGN: Prospective, comparative study. Measurements performed in the first 24 hrs of septic shock. SETTING: A general hospital ICU. PATIENTS: Twelve patients with cirrhosis and 23 patients without cirrhosis admitted for septic shock. MEASUREMENTS AND MAIN RESULTS: Arterial pressure was measured using an arterial catheter. Pulmonary arterial and right atrial pressures were measured by using a pulmonary artery catheter. Cardiac output was determined by using the thermodilution method. Pulmonary arterial L-lactate plasma concentrations were measured using an automated spectrophotometer, and blood temperature was measured using a cardiac output computer. Arterial and mixed venous PO2, PCO2, and pH values were measured by using specific electrodes. Oxygen saturations and hemoglobin concentrations were measured using a hemoximeter. Patients with cirrhosis had decompensated liver disease (grade C of the Child-Pugh classification). The number of Gram-negative infections and therapeutic interventions were similar in both groups. Patients with cirrhosis had higher cardiac indices (5.14 +/- 0.52 [SE] vs. 3.91 +/- 0.30 L/min/m2, p less than .05), plasma lactate concentrations (9.0 +/- 2.0 vs. 5.2 +/- 0.7 mmol/L, p less than .05) and ICU mortality rates (100% vs. 43%, p less than .05), and lower blood temperatures (35.5 +/- 0.6 vs. 37.6 +/- 0.2 degrees C, p less than .05) than patients without cirrhosis. Systemic vascular resistance, arterial pressure, pulmonary arterial pressure, oxygen delivery and consumption, and arterial and mixed venous acid-base status were not significantly different between the two groups. CONCLUSIONS: In patients with cirrhosis, septic shock was characterized by severe liver dysfunction, low blood temperature, marked increases in cardiac index and lactic acidemia, and a 100% ICU mortality rate. These findings should be taken into account if patients with cirrhosis are to be included in controlled studies on septic shock.

Acid-Base Equilibrium↗
PubMed1992

[Effect of the severity of liver disease on renal hemodynamics and renal oxygen consumption in patients with cirrhosis].

In patients with cirrhosis, it has been shown that abnormal systemic and splanchnic hemodynamics and systemic oxygen (O2) consumption are related to the severity of liver disease. Little is known on the relationship between the severity of cirrhosis, on one hand, and renal hemodynamics and O2 consumption, on the other. We measured renal hemodynamics and renal O2 consumption in 31 patients Pugh's grade A and B and in 13 patients grade C. Systemic and splanchnic hemodynamics as well as systemic O2 consumption were studied. Renal blood flow, glomerular filtration rate, and renal O2 consumption were not significantly different between grades A and B and grade C patients. The renal fraction of systemic O2 consumption was higher (11.4 +/- 5.9 vs 7.9 +/- 4.1 percent respectively; P less than 0.05) and the systemic O2 consumption (111 +/- 23 vs 128 +/- 26 ml.min-1.m-2 respectively; P less than 0.05) lower in patients with grade C than in grades A and B patients. The degree of systemic hyperkineticism and portal hypertension was related to the severity of cirrhosis. In our patients, renal hemodynamics and renal O2 consumption were not related to the severity of cirrhosis. However, liver failure was associated with an increased renal fraction of systemic O2 consumption due to unchanged renal O2 consumption and decreased systemic O2 consumption.

Adult↗
PubMed1992

[Hemodynamic effects of the administration of terlipressin alone or combined with nitroglycerin in patients with cirrhosis].

Terlipressin (Glypressin), a synthetic analog of vasopressin, induces arteriolar vasoconstriction which causes both a portal hypotensive effect and certain side-effects on the systemic circulation (elevated arterial pressure and reduced cardiac output). The combination of nitroglycerin with terlipressin might accentuate the portal hypotensive effect and prevent the side-effects on the systemic circulation. The aim of this study was to examine the systemic and splanchnic hemodynamic responses to terlipressin administered alone or combined with nitroglycerin in patients with cirrhosis. Systemic and splanchnic hemodynamics were measured before and 1 h after a bolus of terlipressin (1 to 2 mg IV) given alone (n = 10) or in association with nitroglycerin infusion (25 micrograms/min, n = 9). Terlipressin alone significantly increased the arterial pressure by 21%, systemic vascular resistance by 60%, and significantly decreased cardiac output by 23%. The right atrial and pulmonary pressures significantly increased and the wedged hepatic venous pressure and hepatic venous pressure gradient significantly decreased by 8% and 16%, respectively. The combined therapy decreased the cardiac output by 20%, but did not significantly modify the other systemic and splanchnic hemodynamic values. No significant differences were found between terlipressin and the combined therapy concerning changes in wedged hepatic venous pressure or hepatic venous pressure gradient. We conclude that in patients with cirrhosis, nitroglycerin prevents the deleterious vasoconstrictor and vasopressor effects of terlipressin. However, the combined therapy, as terlipressin alone, decreases the cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1992

[Renal sympathetic nervous activity in patients with cirrhosis].

This study was designed to evaluate the renal contribution to overall sympathetic nerve hyperactivity and the relationships between renal sympathetic activity and systemic, splanchnic or renal hemodynamics in a series of 55 cirrhotic patients. Plasma noradrenaline concentrations were significantly higher in the renal vein than in the pulmonary artery (803 +/- 54 vs 608 +/- 47 pg/ml, P less than 0.01). These two concentrations were significantly correlated, which suggests that renal sympathetic activity and overall sympathetic activity increase in parallel in patients with cirrhosis. However, the estimated renal net release of noradrenaline was not correlated with plasma noradrenaline concentration in the pulmonary artery, suggesting that overall sympathetic nerve activity is not directly dependent on renal contribution in patients with cirrhosis. Neither plasma noradrenaline concentration in the renal vein nor renal net release of noradrenaline were correlated with systemic. splanchnic or renal hemodynamics. Thus, this study did not show a major role of renal sympathetic activity in the hemodynamic changes in cirrhosis.

Adult↗
PubMed1992

Long-term sympathetic and hemodynamic responses to clonidine in patients with cirrhosis and ascites.

The aim of the present study was to examine the short- and long-term effects of the alpha 2-agonist clonidine on sympathetic overactivity, systemic, splanchnic, and renal circulation changes, and abnormal renal sodium excretion in cirrhotic patients with ascites. Of 17 patients, 8 received clonidine and 9 a placebo. Measurements were taken before and after either a single dose of clonidine (150 micrograms) and placebo or a 1-week treatment with clonidine (150 micrograms/day) and placebo. Clonidine but not placebo induced significant short- and long-term decreases in plasma norepinephrine concentrations in the pulmonary artery and the right renal vein. Acute clonidine administration induced a significant reduction in cardiac output, heart rate, arterial pressure, and hepatic venous pressure gradient but had no effect on renal hemodynamics. Long-term clonidine administration induced a significant decrease in the hepatic venous pressure gradient from 20.1 +/- 1.9 to 17.6 +/- 2.0 mm Hg (mean +/- SEM) but had no significant effects on systemic or renal hemodynamics or renal excretion of sodium. It is concluded that long-term clonidine administration in cirrhotic patients induced a sustained decrease in sympathetic nervous activity and portal pressure. In contrast, clonidine had no prolonged effect on systemic hemodynamics. In addition, short- and long-term clonidine administration did not modify renal hemodynamics or induce a natriuretic response in patients with ascites.

Ascites↗
PubMed1991

Intrahepatic cholestasis of pregnancy and acute fatty liver of pregnancy. An unusual but favorable association?

During the 26th week of a first pregnancy, a 25-year-old woman presented with pruritus suggesting an intrahepatic cholestasis of pregnancy. The pruritus, however, persisted despite the premature delivery of a normal newborn at the 35th week. Moreover, aspartate aminotransferase activity increased, reaching a maximum of 38 times normal level on the 17th day after the delivery. Thus, an acute fatty liver of pregnancy was suspected and confirmed by liver biopsy. This patient appeared to have both intrahepatic cholestasis of pregnancy and acute fatty liver of pregnancy, an association not previously reported. It is suggested that intrahepatic cholestasis of pregnancy caused premature delivery, which in turn may have prevented the onset of severe maternal and fetal complications caused by acute fatty liver of pregnancy.

Adult↗
PubMed1991

Clearance of atrial natriuretic peptide in patients with cirrhosis. Role of liver failure.

In non-cirrhotic patients, splanchnic, renal and pulmonary vascular beds are involved in the plasma clearance for atrial natriuretic peptide (ANP). In patients with cirrhosis, endogenous plasma ANP clearance by these vascular beds has not been systematically studied. In addition, the influence of the severity of liver failure on plasma ANP clearance is not known. Thus, in this study we determined plasma ANP clearance by splanchnic, renal and pulmonary circulations using both arteriovenous differences in plasma ANP concentrations and organ plasma flow in 11 patients with cirrhosis. The role of forearm circulation in plasma ANP extraction was also studied. Splanchnic plasma ANP extraction was 29 +/- 7% (mean +/- S.E.) and splanchnic plasma ANP clearance was 404 +/- 130 ml/min (n = 7). Renal plasma ANP extraction and clearance were 32 +/- 8% and 191 +/- 57 ml/min, respectively. Forearm plasma ANP extraction was 11 +/- 4%. Pulmonary plasma ANP extraction and clearance were 8 +/- 5% and 312 +/- 272 ml/min, respectively. A significant negative correlation was found between logarithm of serum bilirubin concentration, on one hand, and splanchnic and forearm plasma ANP extraction, on the other. A significant negative correlation was found between Pugh's score, on one hand, and renal plasma ANP extraction and clearance, on the other. No significant correlation was found between the severity of liver failure and pulmonary plasma ANP extraction and clearance. As a result, we conclude that in cirrhotic patients splanchnic, renal, forearm and pulmonary vascular beds are involved in plasma ANP extraction and clearance. Plasma ANP extraction and/or clearance may be attenuated in the splanchnic, renal and forearm circulations due to liver failure.

Atrial Natriuretic Factor↗
PubMed1991

Regional sympathetic activity, severity of liver disease and hemodynamics in patients with cirrhosis.

One hundred and eight patients with cirrhosis (23 grade A, 46 grade B and 39 grade C, according to Pugh's classification) underwent hemodynamic studies and plasma catecholamine concentration measurements. Blood samples were withdrawn from the pulmonary artery (n = 108), the hepatic vein (n = 108), the azygos vein (n = 59), the right renal vein (n = 66), the right jugular vein (n = 34) and the femoral vein (n = 33). Plasma noradrenaline concentrations in the pulmonary artery and the hepatic vein were more elevated in grade B (607 +/- 52 and 402 +/- 42 pg/ml, respectively) and C patients (630 +/- 59 and 475 +/- 53 pg/ml, respectively) than in grade A patients (411 +/- 51 and 243 +/- 40 pg/ml, respectively). Plasma noradrenaline concentrations from these two vessels were negatively correlated with indocyanine green clearance. These results indicate that both overall and splanchnic sympathetic activities are dependent on altered hepatic function. Significant correlations were found between the wedged hepatic venous pressure and plasma noradrenaline concentrations from either the pulmonary artery, the hepatic vein or the azygos vein. These correlations indicate that both overall and splanchnic sympathetic activities are dependent on the degree of portal hypertension. Moreover, significant correlations were found between hepatic venous plasma noradrenaline concentrations and systemic hemodynamic values, suggesting that splanchnic sympathetic nervous activity could either play a role in the systemic hyperkinetic syndrome or be a consequence of this hyperkinetic syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Selective dopamine DA1 stimulation with fenoldopam in cirrhotic patients with ascites: a systemic, splanchnic and renal hemodynamic study.

We studied the effects of fenoldopam, a selective dopamine DA1 agonist on systemic and splanchnic hemodynamics, renal blood flow and sodium excretion in 12 patients with alcoholic cirrhosis and ascites. Hepatic, azygos and renal veins were catheterized before and after intravenous administration of fenoldopam, 0.05 micrograms/kg/min for 1 hr and increased to 0.1 micrograms/kg/min for another hour. Mean arterial pressure progressively decreased (from 83 +/- 7 to a minimum of 77 +/- 8 mm Hg 100 min after starting the infusion) but returned to baseline level at 120 min. Plasma norepinephrine and renin activity increased (respectively from 567 +/- 297 to 919 +/- 375 pg/ml, p less than 0.05, and from 17 +/- 14 to 23 +/- 15 ng/ml/hr, p less than 0.05). Renal blood flow, urine output or sodium excretion did not change. Sodium output decreased at 1 hr from 6.9 mumol/min to 4.0 mumol/min, p less than 0.05. Both hepatic venous pressure gradient and azygos blood flow significantly increased by 21%. We conclude that the acute administration of fenoldopam did not improve renal hemodynamics or function in patients with cirrhosis and ascites. In addition, dopamine DA1 agonism caused further increases in norepinephrine concentration and plasma renin activity. Portal pressure also increased, probably because of an increase in mesenteric blood flow. These results question the renal benefit and raise concern about the use of dopamine agonists in patients with cirrhosis and ascites.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1991

[Enzymatic release of mycobacteria in natural media].

Polysaccharases release mycobacteria from natural environment. The enzymatic activity works both on the microbial adherence polysaccharides and on the support surfaces (cellulose). The release of mycobacteria from natural environment increases both the number of isolates and the number of species of mycobacteria.

Environmental Microbiology↗
PubMed1991

Relationships between plasma atrial natriuretic peptide concentrations and hemodynamics and hematocrit in patients with cirrhosis.

We studied the relationships in 29 patients with cirrhosis between pulmonary arterial atrial natriuretic peptide concentrations and the following: systemic and splanchnic hemodynamics, the hematocrit, arterial oxyhemoglobin saturation, oxygen tension and the severity of cirrhosis. Plasma atrial natriuretic peptide concentrations ranged from 21 to 208 pg/ml and averaged 78 +/- 8 pg/ml (mean +/- S.E.M.). Simple regression analysis showed significant correlations between plasma atrial natriuretic peptide concentration and the following: hematocrit, mean pulmonary arterial pressure, wedged hepatic venous pressure, free hepatic venous pressure, pulmonary wedged pressure and serum bilirubin concentrations. No significant correlations were found between plasma atrial natriuretic peptide concentrations and all other hemodynamic values, arterial oxyhemoglobin saturation and oxygen tension. Multiple stepwise regression analysis showed that the hematocrit, mean pulmonary arterial pressure and wedged hepatic venous pressure were significant and independent predictors of pulmonary artery plasma atrial natriuretic peptide concentrations (R2 = 0.69). Partial regression coefficients were -0.74 (p less than 0.001), 0.61 (p less than 0.001) and 0.44 (p less than 0.05) for the hematocrit, the mean pulmonary arterial pressure and the wedged hepatic venous pressure, respectively. In conclusion, in patients with cirrhosis, increased plasma atrial natriuretic peptide concentrations were related to the degree of hemodilution, increased pulmonary arterial pressure and the degree of portal hypertension. Plasma atrial natriuretic peptide concentrations were not influenced by the arterial oxygenation levels.

Arteries↗
PubMed1991

Systemic, splanchnic and renal hemodynamic effects of a dopaminergic dose of dopamine in patients with cirrhosis.

The effects of dopamine on kidney function have not been elucidated in patients with cirrhosis. Moreover, although increased portal pressure has been observed with supradopaminergic doses of dopamine in these patients, the splanchnic hemodynamic effects of low doses of dopamine have not been previously studied. Thus we studied the acute systemic, splanchnic and renal hemodynamic effects of a dopaminergic dose of dopamine (1.5 micrograms/kg body wt min) in nine cirrhotic patients. Plasma dopamine levels increased markedly from 35 +/- 20 pg/ml to 31,400 +/- 4,900 pg/ml during dopamine administration. A significant diastolic pressure decrease of 10% was associated with a 15% increase in heart rate. Cardiac output was not altered. Although dopamine significantly increased azygos blood flow by 16%, wedged and free hepatic venous pressures were not altered. Dopamine significantly increased renal blood flow by 31%, but did not change the glomerular filtration rate. We conclude that a dopaminergic dose of dopamine increases azygos blood flow but not the hepatic venous pressure gradient. Finally, although it increases renal blood flow, dopamine does not seem to have any beneficial effects on glomerular filtration rate in cirrhotic patients.

Dopamine↗
PubMed1991

Plasma catecholamines in patients with presinusoidal portal hypertension: comparison with cirrhotic patients and nonportal hypertensive subjects.

During a hemodynamic study, plasma catecholamine concentrations were measured in the pulmonary artery and in the hepatic vein in 18 presinusoidal portal hypertensive patients. Results were compared with those in 15 nonportal hypertensive subjects and in 24 cirrhotic patients in good condition (grade A, according to Pugh's classification). Plasma norepinephrine concentrations in the pulmonary artery or in the hepatic vein were not significantly different between nonportal hypertensive subjects (mean +/- S.E.M.: 271 +/- 36 and 83 +/- 11 pg/ml, respectively) and presinusoidal portal hypertensive patients (273 +/- 33 and 84 +/- 11 pg/ml, respectively). These concentrations were, however, elevated in cirrhotic patients (408 +/- 47 and 256 +/- 45 pg/ml, p less than 0.05 in comparison with the two other groups). These differences suggest that increased sympathetic nervous activity in cirrhosis is associated with the presence of liver disease or increase in sinusoidal pressure. Differences in plasma epinephrine concentrations were not significant among the three groups of patients. However, the existence of a significant correlation between pulmonary artery plasma epinephrine concentration and cardiac index (r2 = 0.46, p less than 0.01) in patients with presinusoidal portal hypertension suggests that the adrenal medulla could play a role in the pathophysiology of the hyperkinetic syndrome of these patients.

Adult↗
PubMed1990

Abnormal pressor response to vasopressin in patients with cirrhosis: evidence for impaired buffering mechanisms.

In patients with cirrhosis, vasopressin infusion induces sustained vasoconstriction and elevation of arterial pressure. The vasopressor effect could be caused by impairment of mechanisms normally aimed at buffering increases in arterial pressure (reflex bradycardia and decreases in arteriolar resistance). We studied the acute effects of continuous vasopressin infusion (0.4 IU/min) on systemic hemodynamics in seven patients with cirrhosis and in six patients without cirrhosis (controls). Vasopressin effects on systemic O2 consumption were also studied. In both groups, vasopressin infusion induced similar peak increases in arterial pressure, followed by similar decreases in heart rate and cardiac output. However, cirrhotic patients and controls differed 30 min after the start of vasopressin infusion. At 30 min, mean arterial pressure, diastolic arterial pressure and systemic vascular resistance remained significantly higher than preinfusion values in patients with cirrhosis. No decrease in systemic O2 consumption occurred in cirrhotic patients. In controls, at 30 min, mean arterial pressure and diastolic arterial pressure had returned to baseline. Systemic vascular resistance was not significantly higher than the preinfusion value and systemic O2 consumption had significantly decreased to below preinfusion values. We conclude that the vasopressor effect of vasopressin is abnormally sustained in patients with cirrhosis. This might be caused by insufficient buffering of vasopressin-induced arteriolar constriction rather than by abnormal vagal control of heart rate. In turn, as suggested by the lack of a decrease in systemic O2 consumption, persistent arteriolar constriction might be related to abnormally sustained sympathetic vascular tone in patients with cirrhosis.

Adult↗
PubMed1989

Combination of ketanserin and verapamil or propranolol in patients with alcoholic cirrhosis: search for an additive effect.

Drugs reported to reduce portal pressure through different mechanisms were combined in the hope of either additive portal hypotensive effects in "responders," or inducing a portal hypotensive effect in "nonresponders" to the initial drug. Seven patients with alcoholic cirrhosis received verapamil, 10 mg i.v., and, 60 min later, ketanserin, 5 mg i.v. Verapamil decreased heart rate and increased free hepatic venous pressure but had no effect on hepatic venous pressure gradient or azygos blood flow. When combined with verapamil, ketanserin significantly diminished wedged hepatic venous pressure and hepatic venous pressure gradient. Ten other patients with alcoholic cirrhosis received propranolol, 15 mg i.v., and 45 min later, ketanserin, 5 mg i.v. In all patients, heart rate, cardiac index and azygos blood flow significantly decreased after propranolol. After propranolol alone, however, wedged hepatic venous pressure decreased in only five patients, responders. In five other patients, defined as nonresponders, propranolol did not decrease this pressure. The addition of ketanserin to propranolol induced further significant reduction in wedged hepatic venous pressure, hepatic venous pressure gradient and azygos blood flow. Among the five nonresponders, three had a reduced wedged hepatic venous pressure after ketanserin was combined. We conclude that verapamil does not reduce portal pressure or collateral blood flow in patients with alcoholic cirrhosis. The splanchnic hemodynamic effects of propranolol and ketanserin appear to be independent and additive, without significant systemic alteration.

Drug Synergism↗