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Biomedical subjects

S Jern

Publications and source records attributed to S Jern.

123 records · Page 7Linked to original sources
PubMed1985

Potentiation of the antihypertensive effect of enalapril by randomized addition of different doses of hydrochlorothiazide.

The purpose of this study was to evaluate the potentiating effect of hydrochlorothiazide (HCTZ) 12.5 or 25 mg once daily when added in a placebo-controlled double-blind randomized study of patients with essential hypertension, whose diastolic blood pressure (DBP) was not adequately controlled (DBP > 90 mmHg) following 6 weeks of single-blind treatment with the angiotensin converting enzyme (ACE) inhibitor enalapril, 20 mg once daily. Forty-eight patients started the first period with enalapril after 4 weeks on placebo. In 13 patients DBP fell to < or = 90 mmHg after enalapril for 6 weeks. In this group supine mean arterial pressure (MAP) was reduced by 13% (P < 0.01). In the patients whose DBP was > 90 mmHg after 6 weeks on enalapril (n = 32) the average supine MAP fell by 9% (P < 0.001). After 3 weeks there was no further drop in blood pressure (BP). Addition of HCTZ to the 32 patients with DBP > 90 mmHg caused a significant further drop in supine BP by 13/7 mmHg with 12.5 mg and by 15/7 mmHg with 25 mg. Seven patients discontinued the study, none due to side effects on enalapril alone. Well-being, assessed with a special questionnaire, was significantly better with enalapril as monotherapy compared with previous treatment, but not different from well-being during the placebo periods. It is concluded that 20 mg enalapril once daily lowered BP effectively and was well tolerated. The maximum BP lowering effect was seen within 3 weeks. Addition of HCTZ caused a significant, and clinically relevant, further drop in BP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Initial clinical experience with ICI 141,292 (Visacor), a new selective beta 1-adrenoceptor blocker with ISA--a multicentre trial in 59 patients.

The objective of this placebo controlled double-blind multicentre (six centres) trial was to investigate the safety and efficacy of ICI 141,292 (Visacor), a new selective beta 1-adrenoceptor antagonist with modest intrinsic sympathomimetic activity (ISA), in hypertensive patients. Fifty-nine patients with mild essential hypertension were randomized to two of five treatment alternatives (placebo, 50 mg, 100 mg 200 mg or 300 mg of ICI 141,292) each given once daily for 2 weeks with a 4 week placebo period before (run in) and in between (wash out) active periods. Thus, each of the five treatments was evaluated in 20-24 patients. After 2 weeks (24 h after last dose) the reduction in recumbent blood pressure for all doses except 50 mg of ICI 141,292 was statistically significant and in the order of 6/4 mm Hg. Standing systolic blood pressure was reduced in a dose-dependent way but only significant for 200 mg of ICI 141,292 (8 mm Hg). Heart rate changes (delta) less than 4 beats/min) were not statistically significant for any dose. It is concluded that ICI 141,292 was well tolerated and had a significant but weak antihypertensive effect which might be explained by too much beta 1-adrenoceptor ISA.

Adrenergic beta-Antagonists↗
PubMed1981

Possible relationship between psycho-emotional factors and haemodynamic patterns in the pathogenesis of mild blood pressure elevation.

1. Psycho-emotional profiles were compared with invasive haemodynamic findings in a population sample of 37 young men (mean age 27 years) with mild blood pressure elevation and in 21 matched normotensive controls. 2. In comparison with normotensive controls, subjects with hyperkinetic blood pressure elevation had higher irritability levels, more guilt feelings and more psychic distressful symptoms. 3. In subjects with blood pressure elevation and normokinetic circulation structural vascular changes were found, and their psycho-emotional profiles showed high irritability levels but not significantly increased guilt or anxiety. 4. These results indicate a relationship between psychological factors and haemodynamic patterns in mild blood pressure elevation. A psychosomatic aetiology in hyperkinetic blood pressure elevation is suggested, and the psychological findings are compatible with a gradual development from hyperkinetic to normokinetic blood pressure elevation.

Adult↗
PubMedDate not supplied

Preserved tissue-type plasminogen activator release and endothelium-dependent vasodilation in postmenopausal women with NIDDM.

We have recently shown that the net release of tissue-type plasminogen activator (t-PA) antigen can be rapidly enhanced by the muscarinic receptor stimulation in healthy males. Since diabetes mellitus has been associated with endothelial dysfunction, the aim of the present study was to compare the endothelium-derived local net release of t-PA with vasodilation in response to muscarinic receptor stimulation by metacholine (Mch) and fluid shear stress in a group of postmenopausal women with non-insulin-dependent diabetes mellitus (NIDDM), and to elucidate the influence of estrogen on this process. Six postmenopausal women with NIDDM were in randomized order exposed to step-wise intra-arterial infusions of Mch (0.1-0. 8-4.0 microg/min) and nitroprusside (SNP; 0.5-2.5-10.0 microg/min). Forearm blood flow (FBF) was assessed by plethysmography. The infusions with Mch and SNP were repeated during simultaneous intra-arterial infusion of 17-beta estradiol (E; 20 ng/min). During placebo infusion, FBF increased significantly in response to Mch and SNP (p<0.001), but no differences between Mch and SNP were found. In parallel to the blood flow increase in response to Mch stimulation, the t-PA net release was increased over 30 times (p<0.001). Estrogen did not produce any change in blood flow or net release of t-PA at baseline or in response to either drug (Mch or SNP). The present study demonstrates a preserved endothelium-dependent vasodilation and stimulated tissue-type plasminogen activator release in NIDDM postmenopausal women in response to Mch stimulation. Acute intra-arterial infusion of 17-beta estradiol did not affect the vasodilation or the t-PA net release.

Aged↗
PubMedDate not supplied

Methodological studies of multiple reference genes as endogenous controls in vascular gene expression studies.

Detection and quantification of differentially expressed genes requires valid and reliable references to control for error variability introduced by preparatory procedures or efficiency of reverse transcription and polymerase chain reaction (PCR) amplification conditions. So-called housekeeping genes are frequently used as endogenous standards, based on the assumption that they are constitutively expressed and independent of experimental conditions. However, if the influence of experimental stimuli is to be analyzed, it cannot a priori be assumed that their expression is unaffected by stimulation. In the present study, the authors studied the expression of different housekeeping genes in the vascular endothelium of intact conduit vessels perfused in a unique biomechanical perfusion model. Ten control gene candidates were investigated by microarray expression analysis. Further, five of these genes were systematically analyzed by real-time reverse transcriptase (RT)-PCR gene quantification and their suitability as reference genes were evaluated. On the basis of these findings, the authors suggest criteria for evaluation of endogenous control genes in vascular perfusion studies.

Biomedical Research↗
PubMedDate not supplied

ST-segment changes and catecholamine-related myocardial enzyme release during alcohol withdrawal.

ST-segment changes and biochemical signs of myocardial injury, and their relation to sympatho-adrenergic activation and cardiac function, were studied in a case series of 19 alcohol-dependent (DSM-III-R) men undergoing in-hospital treatment for alcohol withdrawal. No patient had any clinically apparent heart disease. Analyses of ST-segment depressions > or = 0.1 mV from 24 h ambulatory electrocardiographic recordings revealed horizontal or downsloping ST-segment depressions in seven of the patients. The serum concentration of creatine kinase (CKMB) the day after admission correlated with the urinary excretion of adrenaline (r = 0.74, P < 0.001) and noradrenaline (r = 0.71, P < 0.001). In the two patients with the highest adrenaline excretion and the highest serum concentrations of CKMB and cardiac troponin T, horizontal ST-segment depressions were detected as well. The left ventricular ejection fraction was > or = 0.65 (range 0.65-0.79) in all of the 17 alcoholic men who were examined by echocardiography. Our study shows that alcohol withdrawal is frequently associated with ST-segment abnormalities in men without impairment of heart function and that sympatho-adrenergic activation during withdrawal seems to influence the release of myocardial enzymes. Alcohol withdrawal should thus be considered a condition in which acute cardiac complications may be expected in susceptible individuals.

Adult↗
PubMedDate not supplied

Pafenolol in hypertension: a double-blind randomized trial of a new beta 1-selective adrenoceptor blocker.

The antihypertensive effect of pafenolol, a new beta 1-selective adrenoceptor blocker without intrinsic sympathomimetic activity and three times more selective than metoprolol, was evaluated. Twenty-three patients with essential hypertension, mean age 49 years (range 21-62), were randomized after a 4-week placebo run-in period (double-blind) to 4 weeks of either placebo, pafenolol 50 mg or 100 mg once daily. A submaximal exercise test was performed before and at the end of the treatment period. Pafenolol 50 mg and 100 mg significantly reduced recumbent and standing blood pressure compared with baseline with a mean reduction of 17/14 and 10/12 mm Hg on pafenolol 50 mg and 15/10 and 14/10 mm Hg on pafenolol 100 mg, respectively. Heart rate, both at rest and during exercise, was significantly reduced (p less than 0.05) on pafenolol 100 mg compared with placebo. The reduction in exercise heart rate (percent) was dose dependent and significantly correlated to the log plasma concentration of pafenolol (r = 0.60; p less than 0.05). It can be concluded that pafenolol had a clinically relevant antihypertensive effect when given once daily. No difference between 50 and 100 mg could be demonstrated, thus suggesting that 50 mg may be the preferred dose for antihypertensive treatment.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

A new computerized biomechanical perfusion model for ex vivo study of fluid mechanical forces in intact conduit vessels.

We have developed a new computerized biomechanical ex vivo perfusion system for intact conduit vessels in which a wide range of combinations of intraluminal pressure, fluid flow and shear stress could be set and maintained at target levels in mammalian conduit vessels under controlled metabolic conditions. Mean wall shear stress is calculated using the formula: Accuracy of the wall shear stress calculation was validated by ultrasonographic imaging of the vessel radius. In a series of simulation experiments, the hemodynamic homeostasis functions of the system were challenged by generating a wide range of vascular resistance in artificial vessels and by pharmacologically induced changes in vascular tone in intact human vessels. Despite rapid changes in vessel resistance, shear stress and pressure, or flow and pressure were maintained well at target levels. Shear- and pressure-stimulated production of the vasodilator prostaglandin E2 (PGE2) was used to validate the biological relevance of the model. PGE2 release was significantly more stimulated by high (25 dyn/cm2) compared to low (<4 dyn/cm2) shear (ANOVA, p = 0.012). High compared to low intraluminal pressure depressed the production of PGE2 (ANOVA, p = 0.019). In summary, the computerized perfusion model appears to offer new possibilities of investigating the complex interplay between fluid mechanics and the vascular wall.

Algorithms↗