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Biomedical subjects

F Bendtsen

Publications and source records attributed to F Bendtsen.

At least 91 records · Page 5Linked to original sources
PubMed1990

Hepatic-intestinal disposal of endogenous human alpha atrial natriuretic factor99-126 in patients with cirrhosis.

Hepatic-intestinal disposal of endogenous human alpha atrial natriuretic factor99-126 (ANF) was assessed in 13 patients with cirrhosis (six Child-Turcotte class A, five class B, and two class C) and eight control subjects. The Fick principle was applied during hepatic vein catheterization. Arterial ANF concentration in patients with cirrhosis [11.1 +/- 1.6 (SEM) pmol/L] was not significantly different from that of the control subjects (14.9 +/- 4.2 pmol/L, NS). Arteriohepatic venous extraction ratio of ANF (0.43 +/- 0.05 in cirrhosis vs 0.37 +/- 0.09 in controls, NS), hepatic-intestinal clearance (274 +/- 46 vs 237 +/- 46 ml/min, NS) and removal rate (2.9 +/- 0.88 vs 3.1 +/- 0.77 pmol/min, NS) were closely similar in patients and controls. The present results give no indication that significantly reduced hepatic-intestinal disposal of ANF has a role in causing altered circulating plasma levels of this peptide in cirrhosis. This is in keeping with the presence of vascular clearance receptors and peptidases for ANF degradation independent of hepatocellular function.

Adult↗
PubMed1990

Pancreatic insufficiency. Duodenal and jejunal pH, bile acid activity, and micellar lipid solubilization.

To investigate the course of postprandial lipid solubilization in nine patients with chronic, alcoholic pancreatitis, luminal contents were aspirated from the proximal part of the jejunum for 180 min after a meal containing 1.5% fat. Six of the patients had pancreatic insufficiency, whereas three patients were without insufficiency. pH was measured continuously at two sites: at the level of the papilla of Vater and the aspiration site. The fraction of bile acids in the micellar phase of the jejunal aspirates correlated positively to both pH in the aspirates (p less than 0.05) and the fraction of fat solubilized (p less than 0.02). pH was below 4.0 for a longer period of time in the patients with insufficiency, compared to the patients without. However, pH fluctuated rapidly, and there was no correlation between the continuously measured values at the aspiration site and values in the aspirates. Lipid solubilization was not correlated to the lipase activity in the aspirates. We conclude that acidic bile acid precipitation most likely plays a dominant role in the pathophysiology of pancreatic steatorrhea although the methods available are too crude to disclose the precise course of events.

Adult↗
PubMed1989

Reduced central blood volume in cirrhosis.

The pathogenesis of ascites formation in cirrhosis is uncertain. It is still under debate whether the effective blood volume is reduced (underfilling theory) or whether the intravascular compartment is expanded (overflow theory). This problem has not yet been solved because of insufficient tools for measuring the central blood volume. We have developed a method that enables us to determine directly the central blood volume, i.e., the blood volume in the heart cavities, lungs, and central arterial tree. In 60 patients with cirrhosis and 16 control subjects the central blood volume was assessed according to the kinetic theory as the product of cardiac output and mean transit time of the central vascular bed. Central blood volume was significantly smaller in patients with cirrhosis than in controls (mean 21 vs. 27 ml/kg estimated ideal body weight, p less than 0.001; 25% vs. 33% of the total blood volume, p less than 0.0001). The lowest values (18 ml/kg) were found in patients with gross ascites and a reduced systemic vascular resistance. In patients with cirrhosis central blood volume was inversely correlated to the hepatic venous pressure gradient (r = -0.41, p less than 0.01), and the total blood volume was inversely correlated to the systemic vascular resistance (r = -0.49, p less than 0.001), the latter being significantly reduced in the patient group. Patients with cirrhosis apparently are unable to maintain a normal central blood volume. This may be due to arteriolar vasodilation, portosystemic collateral flow, or sequestration of fluid in the peritoneal cavity, or any combination thereof. The present results indicate that central circulatory underfilling is an integral part of the hemodynamic and homeostatic derangement observed in cirrhosis.

Adult↗
PubMed1989

Effect of omeprazole on intragastric and duodenal bulb acidity in duodenal ulcer patients.

Intraluminal pH was measured simultaneously in the stomach and duodenal bulb with six small, glass electrodes tied together at 1.5-cm intervals. Ten patients with duodenal ulcer disease were studied under fasting conditions and for 3 h after a standard liquid meal on three occasions: day 1, before treatment; day 8, when the proton pump blocker omeprazole had been taken in a daily dose of 30 mg for 7 days consecutively, including the day of the pH study; day 9, 24 h after the last dose of omeprazole. Mean hydrogen ion activity and the percentage of time with pH below 3 was calculated from the digital pH data sampled at a frequency of 1 per second from each electrode. On day 8, five of the patients were permanently anacidic (pH greater than 4) in the stomach and duodenum, while the food-stimulation broke off anacidity for shorter periods in the other five patients. The pH pattern in the duodenal bulb was markedly altered in all patients with disappearance of the typical pH fluctuations, and a decrease in the time that the pH was below 3 from a median value of 30% before treatment to 0% in seven patients and close to 0% in three patients. On day 9, a large patient-to-patient variation was observed in gastric pH: three patients were still anacidic, four were markedly suppressed, but three patients reached near pre-treatment acidity. Duodenal bulb acidity was still decreased significantly on day 9 in all patients, with post-prandial pH below 3 for less than 5% of the time, compared with 30% before treatment.

Adult↗
PubMed1989

Gastric potential difference and pH in ulcer patients and normal volunteers during Stroop's colour word conflict test.

Whether mental stress is important in the pathogenesis of gastric mucosal disorders is not clearly established. This study investigated the relationship between sympathetic activation caused by the Stroop's colour word conflict test and gastric mucosal function, monitored by measuring the gastric mucosal electrical potential difference (PD). In 13 healthy volunteers and 12 duodenal ulcer patients gastric PD, pH, and heart rate were measured continuously during basal conditions, during mental stress evoked by the Stroop's colour word conflict test, and after return to basal conditions. The volunteers fell into two groups: In seven no sympathetic activation was elicited as no changes in heart rate were demonstrated. Gastric pH was unchanged, and PD increased slightly. Sympathetic activation was elicited in the other six with increased heart rate by 18 (6) beats per min. Potential difference declined significantly during sympathetic activation (delta PD = -5 (2)mV, p less than 0.05). Gastric pH increased. Eleven of 12 ulcer patients had sympathetic activation accompanied by a decline in PD, and an increased pH. Sympathetic activation in ulcer patients and volunteers impaired gastric mucosal function, as shown by a decline in gastric PD.

Adult↗
PubMed1989

Comparative pharmacokinetics and pharmacodynamics of lisinopril and enalapril, alone and in combination with propranolol.

In an open, crossover study, the pharmacokinetic and pharmacodynamic profiles of lisinopril and enalapril, administered alone and in combination with propranolol, were evaluated in 12 volunteers. The maximum serum concentration (Cmax) of lisinopril and time to reach maximum concentration (Tmax) were 64 +/- 16 ng/ml and 7.5 +/- 1.5 h, respectively. The area under the serum curve (AUC) was 916 +/- 239 h. ng/ml. The Cmax of enalaprilat (89 +/- 34 ng/ml) was greater than that of lisinopril whilst Tmax was shorter (4.3 +/- 1.7 h) and AUC smaller (718 +/- 17 h.ng/ml) (P less than 0.01). Renal clearance of drug 48 h post-dosing showed that enalaprilat (164 +/- 38 ml/min) was cleared from plasma significantly more rapidly than lisinopril (82 +/- 16 ml/min) (P less than 0.001). Mean supine blood pressure decreased significantly with all treatments, as did heart rate. No significant changes were observed in either the serum concentrations or the urinary outputs of these ACE inhibitors following combination with propranolol, apart from a greater variability of Cmax after addition of propranolol to enalapril compared with lisinopril in combination.

Adult↗
PubMed1988

Bacteriaemia after injection sclerotherapy of oesophageal varices.

Thirty consecutive alcoholic patients with biopsy-proven cirrhosis of the liver and oesophageal varices underwent a total of 47 upper intestinal endoscopies. During 31 of the endoscopies paravariceal sclerotherapy of oesophageal varices was performed. Blood cultures were drawn before and after the procedures. Bacteriaemia after endoscopy was detected on seven occasions: six after sclerotherapy and one after endoscopy without sclerotherapy. This difference did not reach statistical significance. The microorganisms cultured belonged to the normal flora of the skin or the oropharynx. Bacteriaemia was transient and had no clinical consequences.

Adult↗
PubMed1988

Effect of omeprazole and cimetidine on prepyloric gastric ulcer: double blind comparative trial.

We conducted a six week double blind randomised study of 176 patients with prepyloric gastric ulcer to determine whether the proton pump inhibitor, omeprazole 30 mg daily would accelerate healing and pain relief, as compared with cimetidine 1 g daily. At two, four, and six weeks after entry ulcers healed in a larger percentage of patients treated with omeprazole (54, 81, and 86%) than of those treated with cimetidine (39, 73, and 78%) ('intention to treat' cohort; p less than 0.05 at two weeks). A higher proportion of patients on omeprazole became free of pain during the first week of treatment (p less than 0.05). No major clinical or biochemical side effects were noted. Omeprazole is an efficient treatment for patients with prepyloric gastric ulcers.

Adult↗
PubMed1987

Duodenal bulb acidity in patients with duodenal ulcer.

Intraluminal pH was measured simultaneously in the human stomach and proximal duodenum with six small glass electrodes tied together at 1.5-cm intervals. Twenty-four healthy control subjects and 44 patients with duodenal ulcer disease were studied under fasting conditions and for 3 h after a standard liquid meal. Mean and median hydrogen ion activity, percentage of time with pH below 2 and 3, and the frequency of pH fluctuations were calculated from digital pH data sampled at a frequency of once per second from each electrode. None of these measurements of acidity differed significantly between the two groups or between subgroups of normosecretor controls and hypersecretor ulcer patients. At the time of pH study 15 of the patients had endoscopically verified active ulcer disease and 13 patients were without disease activity. Gastric as well as duodenal bulb acidity was the same in these two subgroups. We conclude that even though duodenal ulcer patients deliver more acid into the duodenum, this does not cause increased luminal acid aggression.

Adult↗
PubMed1987

Effect of oral propranolol on splanchnic oxygen uptake and haemodynamics in patients with cirrhosis.

In order to elucidate the effect of beta-adrenergic blockade on liver metabolism and haemodynamics, splanchnic oxygen uptake, hepatic removal of indocyanine green (ICG) and splanchnic and systemic haemodynamics were studied in 13 patients with cirrhosis before and 1.5-2 h after an oral dose of 80 mg propranolol. All patients underwent hepatic vein catheterization and had a primed continuous intravenous infusion of ICG. Azygos vein catheterization was performed in six patients. Splanchnic (hepatic-intestinal) oxygen uptake (median control 68 ml/min vs. beta-blockade 56 ml/min, P less than 0.01), azygos venous oxygen saturation (76 vs. 67%, P less than 0.05), ICG clearance (263 vs. 226 ml/min, P less than 0.01), wedged-to-free hepatic vein pressure (16 vs. 13.5 mm Hg, P less than 0.01), hepatic blood flow (1.18 vs. 0.78 l/min, P less than 0.01), cardiac index (3.42 vs. 2.53 l/min . min 2, P less than 0.01), and heart rate (72 vs. 56 beats per min, P less than 0.01) decreased significantly after oral beta-blockade. The hepatic extraction ratio of ICG increased significantly (0.32 vs. 0.45, P less than 0.01), whereas estimated 'intrinsic' ICG clearance (289 vs. 300 ml/min, n.s.), arterial blood pressure, stroke volume, and systemic vascular resistance remained essentially unchanged. The results indicate that besides the well-known cardiovascular effects of propranolol, beta-adrenergic blockade may also reduce hepatic metabolic functions as evidenced by the significantly decreased splanchnic oxygen uptake. The raised hepatic extraction ratio of ICG may be caused by reduction in hepatic blood flow as well as in intrahepatic shunting.

Administration, Oral↗
PubMed1987

Hepatic venous oxygen content in alcoholic cirrhosis and non-cirrhotic alcoholic liver disease.

Blood gas analyses and hepatic blood flow were determined during hepatic vein catheterization in order to establish a possible hypoxic component in alcoholic liver disease. Fifty-six patients (9 non-cirrhotic liver disease, 14 cirrhosis Child-Turcotte class A, 23 class B, 10 class C) and 10 control subjects were studied. Mean hepatic venous oxygen saturation and tension were almost the same in all groups, and hepatic blood flow was inversely correlated to the arteriohepatic venous oxygen difference (r = -0.53, P less than 0.01). Splanchnic oxygen uptake was similar in all groups studied. The arterio-hepatic venous difference of base excess was small and of the same size in all groups, indicating no enhanced production of lactic acid in the liver. Our results do not support the concept that hepatic venous oxygen content is low in alcoholic liver disease and thereby contributes to hypoxic liver damage.

Adult↗
PubMed1986

Intraluminal pH in the stomach, duodenum, and proximal jejunum in normal subjects and patients with exocrine pancreatic insufficiency.

In situ pH was measured simultaneously with microelectrodes in the stomach, duodenal bulb, midduodenum, duodenojejunal junction, and proximal jejunum. Fourteen healthy subjects and 8 patients with exocrine pancreatic insufficiency were studied under fasting conditions and for 3 h after a standard liquid meal. The luminal pH gradient was steepest in the proximal 10 cm of the duodenum, where acidity was reduced from pH 2 to pH 5 in the fasting state and from pH 1.7 to pH 4.3 in the second and third postprandial hour. Acidity was further reduced in the distal duodenum to a pH between 5 and 6 at the duodenojejunal junction. The frequent wide and rapid pH fluctuations seen in the duodenal bulb were gradually reduced along the duodenum and became rare in the jejunum. In patients with pancreatic insufficiency, duodenal or jejunal acidity did not differ significantly from the controls, with the exception of the single 10-min period occurring 70-80 min after the meal when duodenal bulb pH was 2.1 as compared with 3.1 in the normal subjects (p less than 0.05). All patients, including 2 patients with a very high duodenal acidity, demonstrated a duodenal pH gradient as steep as that found in the normal subjects, indicating sources of bicarbonate other than the pancreas.

Adult↗
PubMed1986

Circulating atrial natriuretic peptide (ANP) and central blood volume (CBV) in cirrhosis.

Endogenous alpha-atrial natriuretic peptide (ANP) in plasma is elevated in various hypervolaemic conditions. Possible relationships between circulating immunoreactive ANP and cardiovascular and splanchnic haemodynamics were therefore studied in patients with cirrhosis (n = 16) and controls (n = 12). Arterial plasma concentration of ANP in supine patients was (mean +/- SEM) 33 +/- 4 vs 41 +/- 10 pg/ml (9.9 +/- 1.2 vs 12.3 +/- 3.0 fmol/l) in controls (n.s.), and there was a weak direct correlation with right atrial pressure (r = 0.36, P = 0.05). There was no relationship with the presence of ascites or diuretic treatment. Central blood volume (CBV, i.e. the blood volume in the heart cavities, lungs, and aorta), determined from the mean transit time of 125I-labelled of 125I-labelled albumin and cardiac output, was significantly reduced in cirrhotics compared to controls (1.45 +/- 0.12 vs. 1.83 +/- 0.10 l, P less than 0.02) and inversely correlated with portal pressure (r = 0.42, P less than 0.05), whereas total plasma volume was somewhat increased (3.51 +/- 0.2 vs. 3.19 +/- 0.2, 0.05 less than P less than 0.1). A high arterio-venous extraction of ANP was found in the splanchnic system (extraction ratio 0.44 vs 0.28), kidney (0.45 vs 0.54), lower limb (0.53 vs 0.40), and forearm (0.27 vs 0.18) in patients and controls, respectively (n.s.). Our results suggest that the lack of elevation of circulating ANP in cirrhosis, even in the presence of actual fluid retention, may be explained by central hypovolaemia in these patients. Turnover and degradation of ANP is rapid and normal, as evaluated from the tissue extraction ratios.

Adult↗