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Biomedical subjects

A Hadengue

Publications and source records attributed to A Hadengue.

At least 163 records · Page 9Linked to original sources
PubMed1990

Effects of haemorrhage and volume expansion on portal-systemic collateral vascular resistance in conscious portal hypertensive rats.

1. In order to study the acute effects of blood volume changes on the vascular resistance of portal-systemic collaterals (collateral vascular resistance), a model of total portal vein occlusion with 100% portal-systemic shunts was developed in the rat. In this model, we determined the haemodynamic effects of haemorrhage (1.8 ml/100 g body weight) or intravenous infusion of a volume expander (1.8 ml/100 g body weight). Cardiac output and regional blood flows were measured by the radioactive microsphere method. 2. Haemorrhage significantly reduced arterial pressure from 108 +/- 4 to 92 +/- 4 mmHg (mean +/- SEM), cardiac output from 56 +/- 4 to 24 +/- 2 ml min-1 100 g-1 body weight, portal pressure from 15.1 +/- 1.5 to 10.0 +/- 1.4 mmHg and portal tributary blood flow from 19.9 +/- 2.3 to 8.3 +/- 1.4 ml/min. Consequently, collateral vascular resistance significantly increased from 6.6 +/- 0.9 x 10(3) to 11.1 +/- 2.0 x 10(3) kPa 1(-1) s. 3. Volume expansion reduced arterial pressure from 98 +/- 3 to 90 +/- 3 mmHg, and significantly increased cardiac output from 43 +/- 3 to 55 +/- 3 ml min-1 100 g-1 body weight, portal pressure from 13.9 +/- 0.7 to 16.5 +/- 0.8 mmHg and portal tributary blood flow from 16.4 +/- 1.3 to 28.2 +/- 3.2 ml/min. Consequently, collateral vascular resistance significantly decreased from 7.0 +/- 0.5 x 10(3) to 4.9 +/- 0.4 x 10(3) kPa l-1 s. 4. This study shows that in rats with portal hypertension, portal-systemic collateral vascular resistance is modified by alterations in blood volume.

Animals↗
PubMed1990

Heterogeneous hepatic venous pressures in patients with liver cancer.

We carried out hepatic vein catheterization in 73 patients with liver cancer, 52 with primary and 21 with metastatic cancer. A heterogeneous hepatic venous pressure gradient, defined as a difference of greater than 4 mmHg between the highest and lowest values of the pressure gradient in any patient, was found in 46% of the hepatocellular carcinoma cases and 43% of the metastatic cancers. Comparing the diagnostic efficacy of this phenomenon with an elevated alpha-fetoprotein, based on 500 randomly selected catheterizations, showed that the heterogeneous gradient was 46% sensitive and 99% specific for the diagnosis of hepatocellular carcinoma, while the alpha-fetoprotein was 67% sensitive and 99% specific. Positive and negative predictive values were 86 and 95%, respectively, for the heterogeneous gradient, and 83 and 97% for the alpha-fetoprotein. Its expense and relative invasiveness make hepatic vein catheterization an unacceptable routine in patients suspected of having hepatic malignancy. However, we suggest that the unexpected finding of a heterogeneous pressure gradient should trigger a search for hepatic cancer.

Adult↗
PubMed1990

Membranous obstruction of the inferior vena cava and hepatocellular carcinoma in a Caribbean patient.

Membranous obstruction of the inferior vena cava has been reported mainly in South Africa, Japan, and India; in 20-40% of patients the disease is complicated by hepatocellular carcinoma. We report a case of membranous obstruction of the inferior vena cava with hepatocellular carcinoma in a 43-year-old Caribbean man of Indian origin. The Caribbean islands may constitute another geographical area where the population is at risk for the development of membranous obstruction of the inferior vena cava and subsequent hepatocellular carcinoma.

Adult↗
PubMed1990

Relative risk of hepatocellular carcinoma in HBsAg positive vs alcoholic cirrhosis. A cross-sectional study.

The etiological link between hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC) has been suggested on epidemiologic, serologic and molecular grounds. This link has, however, recently been questioned by prospective studies suggesting that HBV infection also causes cirrhosis and that whatever the cause of cirrhosis, the risk of developing HCC could be roughly similar. All male patients first admitted to Hôpital Beaujon with cirrhosis or HCC from 1983 to 1987 were included in a cross-sectional study. A total of 277 new patients with cirrhosis (but free of HCC) were admitted, of whom 55 were HBsAg positive, and 181 were alcoholic. During the same period, 117 new patients with HCC were admitted, 48 in association with alcoholic cirrhosis, 36 with HBsAg positive cirrhosis. The relative risk (odds ratio) of HCC was 2.5 (95% confidence interval, 1.46-4.37; p = 0.0011) in patients with HBsAg positive cirrhosis as compared to patients with alcoholic cirrhosis. HBsAg positive patients were significantly younger than their alcoholic counterparts (48 +/- 14 vs 54 +/- 10 years in the cirrhotic group; 49 +/- 12 vs 62 +/- 8 years in the HCC group). We conclude that, using the methodology of a cross-sectional study, the relative risk of HCC was about twice greater in HBV-associated than alcoholic cirrhosis. The results of longitudinal prospective studies examining this issue might be biased by selecting patients older than the mean age of HCC occurrence or excluding patients with HCC when present at first admission.

Carcinoma, Hepatocellular↗
PubMed1990

A pitfall in azygos vein cannulation in cirrhotic patients: mistaken cannulation of the mammary vein.

Azygos venous flow can be measured by a thermodilution catheter in patients with cirrhosis. This is a useful technique since azygos flow is thought to reflect the superior portosystemic collateral flow in these patients. The authors report 3 cases in which mistaken internal mammary vein cannulation mimicked azygos vein cannulation in the supine fluoroscopic view. A lateral fluoroscopic view confirmed internal mammary cannulation. They suggest that if the azygos arch is unpronounced or flow measurements are unexpectedly low in patients with portal hypertension due to cirrhosis, a lateral view be performed to rule out internal mammary vein cannulation.

Azygos Vein↗
PubMed1990

Pharmacokinetics of ketanserin in patients with cirrhosis.

The pharmacokinetics of ketanserin, a new serotonin S2 (5HT2) antagonist, were studied in 26 patients with cirrhosis. Patients were randomised to receive either a single oral dose of ketanserin 20mg (n = 14) or 40mg (n = 8) or an intravenous dose of ketanserin 5mg (n = 4). The plasma kinetics of ketanserin and its metabolite ketanserinol were determined over 48 hours, by high pressure liquid chromatography with a fluorometric detector. Pharmacokinetic parameters were calculated using noncompartmental analysis based on a statistical moment theory. The first-pass effect of ketanserin was markedly decreased after oral administration compared with results previously obtained in healthy subjects. The peak concentration was not higher in cirrhotic patients than in controls. This result could be due to an increase in the initial volume of distribution. The production of ketanserinol was reduced in cirrhotics. A decreased mean ketanserin elimination half-life (t1/2 = 12 +/- 4 and 10 +/- 3h vs 16 +/- 3 and 18 +/- 4h in healthy controls after oral ketanserin 40mg and intravenous ketanserin 5mg, respectively) contrasted with a substantial increase in t1/2 for ketanserinol (33 +/- 13 vs 19 +/- 4h). The volumes of distribution were also markedly reduced in patients with cirrhosis. These results suggest either a reduction in the oral dosage of ketanserin or an increase in the interval between doses in patients with cirrhosis.

Administration, Oral↗
PubMed1990

[Fatal fulminant hepatitis in 2 women taking toloxatone (Humoryl)].

We report two cases of fulminant hepatitis which might be due to toloxatone, a new type-A monoamine oxidase inhibitor. Hepatitis occurred 20 days after the beginning of toloxatone administration in the first case and 138 days after the reintroduction of treatment in the second case. Clinical features included vomiting and jaundice, followed by asterixis and coma. Histologically, hepatic cell necrosis was predominant in the centrilobular area in the first case, and affected the entire lobule in the second case. Both patients died despite emergency liver transplantation.

Acute Disease↗
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↗
PubMed1989

Discrepancy between portal pressure and systemic hemodynamic changes after incremental doses of propranolol in awake portal hypertensive rats.

The effects of increasing doses of propranolol were studied in awake portal hypertensive rats in order to elucidate the relative effects of the beta-blocker on systemic and splanchnic circulation. Hemodynamic responses to 0.1, 0.2 and 0.4 mg per min infusions of propranolol were compared with placebo in awake rats with portal hypertension due to portal vein stenosis. Heart rate significantly and progressively decreased from 356 +/- 13 to 293 +/- 10 beats per min (mean +/- S.E.). Cardiac output significantly decreased from 54 +/- 3 to 42 +/- 3 ml per min per 100 gm body weight at the highest dose. Significant decrease in portal tributary blood flow from 27 +/- 1 to 18 +/- 1 ml per min, at 0.4 mg per min dose, was due not only to the decrease in cardiac output but also to a significant increase in portal tributary vascular resistance from 269 +/- 17 to 368 +/- 31 dyne per sec per cm5 x 10(3). However, portal pressure showed only an insignificant decrease from 14.9 +/- 1.1 to 14.1 +/- 1.4 mmHg. The reduction in portal pressure being minimal, in spite of a significant decrease in portal tributary blood flow, is explained by an increase in combined hepatic and collateral resistance from 44 +/- 2 to 66 +/- 4 dyne per sec per cm5 x 10(3), p less than 0.05, at 0.4 mg per min dose. We conclude that the systemic and splanchnic effects of propranolol show discrepancy at two levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Relationship between oxygen transport and oxygen uptake in patients with cirrhosis: effects of vasoactive drugs.

To elucidate the relationship between oxygen transport and uptake in cirrhosis, we studied the effects of three vasoactive drugs that change O2 transport. Systemic hemodynamics, blood gases and lactate concentration were measured in patients with alcoholic cirrhosis before and after intravenous dobutamine, propranolol and nitroglycerin. Nine patients received successively dobutamine and then propranolol. Ten patients received nitroglycerin. Three other patients without cirrhosis (controls) received dobutamine. In patients with cirrhosis, dobutamine infusion was accompanied by a significant increase in cardiac output (+21%), systemic O2 transport (+21%) and O2 uptake (+12%), whereas O2 extraction ratio and arterial lactate concentration did not change significantly. Propranolol administration was followed by a significant decrease in cardiac output (-24%) and systemic O2 transport (-25%) and a significant increase in O2 extraction ratio (+19%), whereas O2 uptake and arterial lactate concentration did not change. Nitroglycerin infusion was accompanied by a significant decrease in cardiac output (-21%), systemic O2 transport (-26%) and O2 uptake (-10%), whereas O2 extraction ratio (+18%) and arterial lactate concentration (+31%) significantly increased. In control patients, dobutamine infusion was accompanied by an increase in cardiac output and in systemic O2 transport and by a decrease in O2 extraction ratio, whereas O2 uptake was not modified. These results suggest that O2 uptake may be abnormally dependent on O2 transport in patients with cirrhosis.

Biological Transport↗
PubMed1989

Low dose of nitroglycerin failed to improve splanchnic hemodynamics in patients with cirrhosis: evidence for an impaired cardiopulmonary baroreflex function.

High doses of nitroglycerin may decrease portal pressure in patients with cirrhosis with untoward effects such as arterial hypotension and a decrease in systemic O2 uptake. In the present study, low doses of nitroglycerin (7 to 15 micrograms per min, i.v.) were administered in 11 patients with cirrhosis in order to unload cardiopulmonary baroreceptor--one of the possible mechanisms by which nitroglycerin may improve splanchnic hemodynamics--and moreover to avoid deleterious systemic effects. Nitroglycerin significantly decreased right atrial pressure (-35%) and pulmonary wedged pressure (-27%) with significant increase in plasma norepinephrine concentration (+23%), which indicated that cardiopulmonary baroreceptor unloading was achieved. Changes in systemic hemodynamics were slight, although significant, with a decrease in arterial pressure (-8%) and an increase in heart rate (+8%); this indicates a minimal effect on high-pressure baroreflexes. In contrast, no significant change was observed in hepatic venous pressure gradient, hepatic blood flow and azygos blood flow. However, the fraction of cardiac output reaching the azygos system significantly increased by 18%. Plasma renin activity did not change significantly. Moreover, O2 transport and uptake were significantly decreased. These findings show that low doses of nitroglycerin failed to improve splanchnic hemodynamics in patients with cirrhosis. These results suggest an impaired cardiopulmonary baroreflex function which is probably located on the efferent arch.

Adult↗
PubMed1989

Hepatic denervation alters hemodynamic response to hemorrhage in conscious rats.

We investigated the effect of liver denervation on cardiovascular homeostasis. Three days after surgical denervation of the liver, hemodynamic studies (radioactive microsphere method) were conducted in conscious rats. The efficacity of the liver denervation procedure was confirmed by a significant decrease in norepinephrine content in various lobes of the liver. Liver denervation did not affect either systemic or splanchnic resting hemodynamics. However, hemorrhage (2 ml per 100 gm body weight) induced a decrease in cardiac index which was significantly more marked in rats with liver denervation (-62 +/- 3%) than in sham-operated rats (-47 +/- 5%; p less than 0.05). This more severe response to hemorrhage may be due to a lack of portal territory vasoconstriction since the fraction of cardiac output reaching portal territory did not decrease during hemorrhage in rats with liver denervation (16 +/- 1% to 14 +/- 1%) but significantly decreased in sham-operated rats (from 15 +/- 1% to 11 +/- 1%, p less than 0.05), this value being significantly lower, after hemorrhage, in sham-operated rats than in denervated rats. The results confirm the lack of tonic neural influence on hepatic circulation during physiological experimental conditions and indicate that hepatic nerve function has a significant contribution to the overall cardiovascular homeostasis.

Animals↗
PubMed1989

Membranous obstruction of the inferior vena cava associated with a myeloproliferative disorder: a clue to membrane formation?

Although membranous obstruction of the inferior vena cava is frequently assumed to be a congenital defect, it has recently been hypothesized that it could be acquired and secondary to thrombosis at the ostium of hepatic veins. We report the case of a membranous obstruction of the inferior vena cava responsible for isolated hepatomegaly in a young Frenchman. No known cause of thrombosis was found but spontaneous formation of erythroid colonies occurred on bone marrow cultures. This indicated the existence of a latent myeloproliferative disorder, a frequent cause of hepatic vein thrombosis. We suggest that this association of a membranous obstruction of the inferior vena cava with a known, albeit often overlooked, cause of hepatic vein thrombosis provides strong support to the thrombosis theory of membrane formation.

Adult↗
PubMed1989

Effects of oxygen inhalation on tissue oxygenation in patients with cirrhosis. Evidence for an impaired arterial baroreflex control.

In patients with cirrhosis, O2 uptake, i.e., O2 consumption, is abnormally decreased. We administered 50% O2 for 30 min in eight patients with alcoholic cirrhosis to determine whether the subsequent increase in arterial O2 content may correct the low O2 consumption. In addition, we studied in these patients the reflex control of cardiac output and blood pressure by arterial baroreceptors, as O2 inhalation induces a systemic vasoconstriction. Arterial O2 tension, oxyhaemoglobin saturation and arterial O2 content significantly increased as well as systemic vascular resistance and arterial pressure. In contrast, O2 consumption (which was below normal values) under basal conditions, O2 transport, O2 extraction ratio, heart rate, right atrial and pulmonary wedged pressures, cardiac output, hepatic venous pressures, hepatic and azygos blood flows were unaffected by O2 administration. In three patients receiving air, no significant change was observed. Our results show that, in patients with cirrhosis, inhalation of 50% O2 does not correct O2 consumption. We may conclude that reflex control of cardiac output and arterial pressure by arterial baroreceptors is impaired in these patients.

Blood Pressure↗
PubMed1989

Effects of glucagon on systemic and splanchnic circulation in conscious rats with biliary cirrhosis.

To elucidate the relationship between the haemodynamic changes and glucagon in cirrhosis, we infused physiologic and supraphysiologic doses of this hormone in conscious rats with portal hypertension due to biliary cirrhosis. Cardiac output and splanchnic organ blood flows were measured by the radioactive microsphere method before and 30 min after glucagon infusion at doses of 2, 5 and 10 ng/min. Serum glucagon increased from a basal level of 92 +/- 17 pg/ml (mean +/- S.E.) to 399 +/- 89, 1151 +/- 136 and 2064 +/- 328 pg/ml, respectively, in sham-operated rats, and from 743 +/- 75 pg/ml to 1497 +/- 197, 1583 +/- 356 and 2957 +/- 649 pg/ml, respectively, in cirrhotic animals at 2, 5 and 10 ng/min doses. In both groups, cardiac output did not change after glucagon infusion at 2 and 5 ng/min doses, suggesting that factors other than glucagon are primarily responsible for the systemic hyperdynamic circulation in cirrhosis. Portal tributary blood flow increased significantly after glucagon infusion in sham-operated rats by 34 and 65% at doses of 5 ng/ml and 10 ng/ml, respectively, and in cirrhotic rats by 29% at a dose of 10 ng/ml. However, portal tributary blood flow did not change after glucagon infusion at the physiologic dose of 2 ng/min. This study shows that glucagon infused at a physiologic dose does not increase splanchnic blood flow, although it increases portal tributary blood flow at supraphysiologic doses. The discrepancy between blood glucagon levels and splanchnic haemodynamic responses suggests that glucagon plays only a minor role and that other factors are primarily responsible for the hyperdynamic state of the splanchnic circulation in rats with biliary cirrhosis.

Animals↗