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Biomedical subjects

J Weil

Publications and source records attributed to J Weil.

At least 19 recordsLinked to original sources

Effects of graded exercise on blood pressure, heart rate, and plasma hormones in cardiac transplant recipients before and during antihypertensive therapy.

The effects of graded supine ergometry on blood pressure, heart rate, and plasma hormones were studied in 14 hypertensive heart transplant recipients before and after 2 weeks and 6 months of enalapril (20 mg/day) plus furosemide (20-80 mg/day) alone or combined with verapamil (120-360 mg/day). Each time, measurements were obtained at rest and at 25 and 50 W exercise. Antihypertensive therapy normalized blood pressure, while heart rate and the blood pressure response to exercise remained unaltered. Pretreatment resting plasma renin activity and catecholamine levels were normal, while atrial natriuretic factor and cyclic guanosine monophosphate concentrations were elevated. All hormones increased significantly with exercise. During treatment, plasma renin activity increased and atrial natriuretic factor and cyclic guanosine monophosphate levels decreased significantly, with a blunted exercise response; concentration of catecholamines increased significantly, with augmented exercise response. Thus, the chosen regimen allowed effective, lasting BP control in hypertensive transplant patients but was associated with significant changes in plasma hormones. Whereas the rise in plasma renin activity may be attributed to converting enzyme inhibition, the decreases in atrial natriuretic factor and cyclic guanosine monophosphate and increases in catecholamine levels seem to indicate marked changes in resting and particularly exercise hemodynamics during antihypertensive therapy.

Adult

Does a previous course of tripotassium dicitrato bismuthate affect the subsequent chances of successful Helicobacter pylori eradication?

We have performed a retrospective study of 103 patients with either peptic ulcer or non-ulcer dyspepsia, infected with metronidazole-sensitive strains of Helicobacter pylori (H. pylori), who were treated with a combination of tripotassium dicitrato bismuthate and metronidazole for a period of at least two weeks. Dual therapy with tripotassium dicitrato bismuthate plus metronidazole showed similarly high eradication rates (greater than or equal to 80%) of H. pylori from patients irrespective of age, gender or clinical diagnosis. Most importantly, dual therapy achieved a similar eradication rate of H. pylori infection in 41 patients who had previously been treated with tripotassium dicitrato bismuthate alone or in combination with an antibiotic other than metronidazole. It therefore appears that H. pylori does not become resistant to treatment with tripotassium dicitrato bismuthate.

Adult

Effects of oral pantoprazole on 24-hour intragastric acidity and plasma gastrin profiles.

Pantoprazole selectively blocks gastric parietal cell H+,K(+)-ATPase. To define a dosage regimen for clinical trials we compared the effect of pantoprazole 40 and 60 mg daily on 24-h intragastric acidity and plasma gastrin concentrations using a double-blind, randomized, cross-over design. Eleven men took each of the three regimens (placebo, 40, 60 mg) for 5 days. On Day 5, 24-h pHmetry and plasma gastrin profile were performed. A consistent decrease in intragastric acidity with each dosage regimen was shown by a rise in 24-h median pH from 1.4 (1.2-1.8, IQR) on placebo to 2.3 (1.8-4.4, P = 0.0022) during pantoprazole 40 mg and to 3.5 (2.6-4.9, P = 0.0017) during 60 mg. Pantoprazole 40 and 60 mg maintained the intragastric pH above 3 for 33% and 58% of time, respectively, compared with 15% time with placebo. Twenty-four-hour integrated plasma gastrin concentration rose from 478 to 1798 and 1962 pmol.h/L, respectively. The drug was well tolerated. The decrease of acidity was dose related and should result in clinical efficacy similar to other antisecretory drugs. It is not known whether higher doses might abolish acid secretion. The optimal dose of pantoprazole is yet to be established.

2-Pyridinylmethylsulfinylbenzimidazoles

Urodilatin and atrial natriuretic peptide are present in the urine of healthy neonates and young infants.

Urine sampling has been proposed as noninvasive monitoring of plasma atrial natriuretic peptide (ANP) in neonates, assuming urine contains only filtered plasma ANP. Recently, urodilatin, another natriuretic peptide, which is cross-reactive to ANP in the ANP radioimmunoassay (ANP-RIA), has been isolated from the urine of adults. We studied the urine of healthy term neonates and young infants for the presence of urodilatin. In all urine samples, we found three peaks of ANP-RIA-reactive material: the first one in the position of urodilatin, the second one coeluting with synthetic ANP and a third late eluting peak, possibly containing degradation products. The physiological significance of these findings remains to be investigated.

Atrial Natriuretic Factor

Combination of high-performance liquid chromatography and radioimmunoassay for the measurement of urodilatin and alpha-hANP in the urine of healthy males.

Urodilatin (ANP-(95-126)), a natriuretic peptide in urine, and alpha-hANP (ANP-(99-126)) are crossreactive in the radioimmunoassay of alpha-hANP (ANP-RIA). We therefore developed a method to separate physiological amounts of urodilatin and alpha-hANP in urine by high-performance liquid chromatography (HPLC) followed by ANP-RIA of the separated fractions. We studied urine samples of 10 healthy adult males with a plasma alpha-hANP level of 41 +/- 21 pg/ml (mean +/- SD) and a total urinary ANP-RIA reactivity of 40 +/- 21 pg/ml. In all urine samples we found three peaks of ANP-RIA reactivity, the first one coeluting with synthetic urodilatin, the second one with the retention time of alpha-hANP and a late eluting ANP-RIA-reactive peak, possibly containing degradation products. The ratio of urodilatin/alpha-hANP was 0.77 +/- 0.17.

Adult

Omeprazole and Helicobacter pylori: temporary suppression rather than true eradication.

Twenty-four Helicobacter pylori (H. pylori)-positive patients were treated for 28 days with either 20 mg omeprazole o.m. (n = 12) or 40 mg omeprazole o.m. (n = 12). Clearance (absence of H. pylori at the end of or shortly after treatment) and eradication (absence of H. pylori 1 month after cessation of treatment) were assessed using the 14C-urea breath test. Observed clearance and eradication were: 20 mg omeprazole 3/12 and 0/12; 40 mg omeprazole 6/12 and 1/12 respectively. The effect on H. pylori is probably due to the change in gastric pH from acid to neutral, however it is insufficient to recommend the inclusion of omeprazole in regimens aimed at eradicating H. pylori.

Adult

Helicobacter pylori: treatment with combinations of pivampicillin and tripotassium dicitrato bismuthate.

Fifty Helicobacter pylori- (H. pylori) positive patients entered an open study and were assigned to one of four treatment regimens comprising: pivampicillin (500 mg b.d.) for 2 weeks +/- tripotassium dicitrato bismuthate (tablet or liquid form) for one month. The 14C-urea breath test was used to evaluate clearance (negative at the end of treatment) and eradication (negative at 1 month post-treatment) of H. pylori. Clearance rates were 20% (2/10) after pivampicillin alone, 86% (12/14) after tripotassium dicitrato bismuthate tablets (240 mg b.d.) plus pivampicillin, 67% (6/9) after tripotassium dicitrato bismuthate tablets (120 mg q.d.s.) plus pivampicillin, and 100% (13/13) after tripotassium dicitrato bismuthate liquid (120 mg in 5 ml q.d.s) plus pivampicillin. The eradication rates were 0% (0/10), 13% (2/15), 0% (0/11) and 54% (7/13), respectively. Combination of the results from the 2 tripotassium dicitrato bismuthate tablet/pivampicillin groups gave an eradication rate of 7.7% (2/26) which was significantly lower than the 53.9% (7/13) obtained with tripotassium dicitrato bismuthate liquid/pivampicillin (P less than 0.02). In conclusion, a liquid tripotassium dicitrato bismuthate pivampicillin combination may be of special use in the treatment of H. pylori-positive patients when triple therapy is contraindicated (e.g. patient sensitivity/allergy to metronidazole) or when the H. pylori isolate is resistant to metronidazole.

Adult

Responsiveness of raised pulmonary vascular resistance to oxygen assessed by pulsed Doppler echocardiography.

OBJECTIVE: To assess whether changes in Doppler echocardiographic indices in the pulmonary artery correlated with changes in pulmonary vascular resistance. DESIGN: Acceleration time, ejection time, maximal flow velocity, and velocity time integrals were measured at the same time as pressure and oxygen saturation measurements in room air and during 10 minutes of oxygen breathing in the catheterisation laboratory. Pulmonary vascular resistance and pulmonary blood flow (Qp) were calculated from catheterisation data by use of the Fick principle. PATIENTS: 14 consecutive patients with a congenital heart defect and a left to right shunt associated with raised pulmonary artery pressure who underwent routine diagnostic cardiac catheterisation to assess their pulmonary vascular resistance. RESULTS: Though pulmonary vascular resistance and systolic pulmonary artery pressure fell significantly during oxygen administration, there was no significant change in the acceleration time or ejection time. Peak velocity increased significantly during oxygen administration. During oxygen breathing Doppler derived measurements of pulmonary flow showed a significant increase in Qp similar to the increase in Qp measured by the Fick principle. There was no significant correlation between the fall in pulmonary vascular resistance and the increase in acceleration time or ejection time, increase in peak velocity, increase in pulmonary artery diameter, or increase in Doppler derived pulmonary blood flow. CONCLUSIONS: Measurements of acceleration and ejection time by Doppler echocardiography did not predict the response of pulmonary artery pressure and resistance to oxygen. Though changes in maximal flow velocity across the pulmonary artery and in Doppler derived pulmonary blood flow measurements became significant during oxygen breathing, the correlation of these changes with fall in pulmonary vascular resistance was poor.

Blood Flow Velocity

Acute effects of beta-adrenergic stimulation with dobutamine on the plasma levels of atrial natriuretic peptide and cyclic guanosine monophosphate in patients with chronic heart failure.

In eight patients (63 +/- 7.9 years) with angiographically documented dilated cardiomyopathy, we studied the acute effects of a beta-adrenergic stimulation with dobutamine on the plasma levels of atrial natriuretic peptide (ANP) and cyclic guanosine monophosphate (cGMP). For this purpose, a four-point dose-response curve was prepared for dobutamine starting with an initial dose of 2.5 micrograms kg-1 min-1, which was increased by 2.5 micrograms kg-1 min-1 at a time up to altogether 10 micrograms kg-1 min-1. Each stage lasted 15 min. ANP and cGMP were determined from the mixed venous blood before the start (t0), at 5 micrograms kg-1 min-1 after 30 min (t1), at 10 micrograms kg-1 min-1 after 60 min (t2) and after subsidence of the drug effect after 90 min (t3). ANP dropped from 380 +/- 151 pg ml-1 (normal range up to 55 pg ml-1) by 38% to 235 +/- 90 pg ml-1 after 30 min and by another 17% to 171 +/- 45 pg ml-1 after 60 min. After the effect of dobutamine had subsided, an increase by 41% to 325 +/- 139 was reached. There was a parallel drop of the mean cGMP level from 5.4 +/- 1.4 pmol.ml-1 by 28% to 3.89 +/- 1.4 pmol.ml-1 (30 min) and by another 14% to 3.2 +/- 0.7 pmol.ml-1 (60 min). After 90 min it was 18% below the initial value, being 4.4 +/- 1.3 pmol.ml-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Plasma hormones in patients with chronic heart failure before and early after orthotopic heart transplantation.

The aim of this prospective study was to investigate both vasoconstricting and vasodilating plasma hormones and plasma factors regulating the circulatory homeostasis in patients with endstage congestive heart failure before and early after orthotopic heart transplantation and to evaluate factors which may influence their regulation. 19 patients with endstage congestive heart failure were analyzed serially before and 3-4 weeks after orthotopic heart transplantation. A significant decrease in plasma concentrations of noradrenaline (457 +/- 202 vs. 204 +/- 88 pg/ml; p less than 0.001), adrenaline (43 +/- 32 vs. 26 +/- 11 pg/ml), atrial natriuretic peptide (341 +/- 218 vs. 139 +/- 64 pg/ml; p less than 0.005), cyclic guanosine monophosphate (13.8 +/- 7.8 vs. 6.6 +/- 2.2 pmol/ml, p less than 0.05) and in plasma renin activity (16.6 +/- 13.0 vs. 2.0 +/- 2.4 ng AI/ml/h; p less than 0.01) was found after transplantation. The data indicate that the marked increase in plasma catecholamine concentrations and renin activity in endstage congestive heart failure is reversible as early as 3-4 weeks after heart transplantation. This is most likely the consequence of normalization of cardiac function. While elevation of atrial natriuretic peptide and cyclic guanosine monophosphate as well as increased vasoconstrictor activity in heart failure appear to be related to impaired ventricular function, the persistent moderate elevation of both vasodilating agents after transplantation may be compensatory to counteract cyclosporin-induced arterial hypertension after heart transplantation.

Adult

Mothers' postcounseling beliefs about the causes of their children's genetic disorders.

Mothers' postcounseling beliefs about the causes of their children's genetic disorders were investigated by means of a Q-sort consisting of 54 statements of possible beliefs that were sorted into nine groups of six items each on the basis of congruence with the subject's beliefs. The subjects were well educated, knowledgeable about the genetics of their child's disorder, and indicated a high level of belief in genetic causes. Differences in beliefs were associated with differences in genetic etiology, indicating that beliefs were affected by the specific information provided in genetic counseling. Factor analysis identified a cluster of Q-sort items characterized by a highly personal relationship to the cause of the disorder (e.g., personal attributes, being selected and blessed, and God's actions). Subjects who rated these items low had a belief pattern, designated impersonal, that was consistent with a scientific worldview and that indicated psychological distancing from the cause of the child's disorder. Subjects who rated these items high, the personal belief pattern, had a mixture of scientific and nonscientific beliefs that indicated a sense of personal involvement in the cause of the child's disorder. Subjects with the two belief patterns were equally knowledgeable about the genetics of the disorder. Thus, the personal belief pattern did not appear to interfere with acceptance or understanding of the information provided in genetic counseling.

Adult

Effects of a small bolus dose of ANF in healthy volunteers and in patients with volume retaining disorders.

Thirty-seven patients with volume-retaining disorders (liver cirrhosis with ascites, n = 8; heart failure NYHA III-IV, n = 12; endstage renal failure, n = 17) and twelve healthy age-matched controls were given a small dose (33 micrograms) of hANF (human atrial natriuretic factor). We tested the resulting hemodynamic and renal effects as well as the effect on plasma cyclic GMP levels and compared them with the properties of platelet ANF receptors. The ANF injection evoked an increase in cyclic GMP plasma levels of 19.3 +/- 2.2 nM in healthy controls. This increase tended to be smaller in the cirrhosis group (15.5 +/- 3.3 nM) and in the heart failure group (16.8 +/- 2.3 nM) than in the dialysis group (20.5 +/- 2.5 nM). The invasion rates of cyclic GMP were comparable in all groups, but the evasion rates increased more in the heart failure and endstage renal failure groups (27.9 +/- 7.7 min and 26.1 +/- 3.4 min, respectively) than in the cirrhosis and control groups (14.9 +/- 1.9 min and 14.2 +/- 1.9 min, respectively). Patients with endstage renal failure and congestive heart failure showed a smaller decrease in diastolic blood pressure than controls and patients with liver cirrhosis. Renal actions of ANF were diminished in cirrhosis and heart failure patients. Binding capacities of platelet ANF receptors were higher in the control group (12.2 +/- 1.5 receptors/cell) than in the patient groups (cirrhosis, 7.8 +/- 1.2; endstage renal failure, 8.0 +/- 0.9; heart insufficiency, 8.0 +/- 1.0 receptors/cell), with no differences among the patient groups. Binding affinities were not significantly different. Correlation analysis showed that the relationship between the actions of ANF and the increases in plasma cyclic GMP levels is loose and cannot predict the hemodynamic or renal effects of exogenous ANF in a given patient. Although the behavior of plasma cyclic GMP levels fails to predict the responsiveness of the body to ANF in a given patient, it does reflect the differences between the patient groups and the control group. In contrast, we found no correlation between the properties of platelet ANF receptors and ANF action.

Adult