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Biomedical subjects

B Weisser

Publications and source records attributed to B Weisser.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Dyslipidemia and personality--an investigation of 376 aged athletes].

UNLABELLED: There exists much evidence for a close connection between "Type A" personality and a high cardiovascular risk. In addition, there seems to be a strong association between high lipids and personality as well. In this investigation we addressed the question of this relationship. METHODS AND RESULTS: In a sample of n = 376 male life-time athletes, born 1910 to 1940 a retrospective longitudinal study aiming at motor development and influencing factors was conducted including for instance data concerning health status, personality, locus-of-control. In the sample (medium age of 65 years) the prevalence for hypercholesterin-/triglyceridemia equals 35%. The objective of the present study was the identification of sub-samples with significantly higher prevalences defining personality features, locus-of-control and closely related constructs as independent variables. The data analysis was performed using CHAID. The sample is separated into 14 subgroups by the combination of 10 predictors. Above average prevalences were found in people with the key personality features of "tension", "neuroticism", "aggressiveness", and "extraversion" in several combinations. If a low personal-best or many statements "sport becomes less important" gain relevance, the prevalence rises to 100%. A trustworthy occupation and "neuroticism" predict a percentage of 83%. "Aggression" and "extraversion" are related to an unhealthy, "worrying about ones health" to a healthy lifestyle. The latter as well as low "life-satisfaction" and feeling "dependent upon others" correspond to compensatory sport engagement. Many results therefore support findings concerning the protective power of sport and the negative impact of tension, neuroticism, and inactivity. Our results showed a close association between features of "Type A" personality and high lipids in older life-time athletes. It is only possible to speculate about causality. A plausible idea is to consider a common patho-physiological basis of changes in metabolism and personality (e.g. sympathic activity or "drive"). In any case, the above mentioned personality features moderate unhealthy behavior patterns leading to hypercholesterin-/triglyceridemia.

Age Factors↗
PubMed1999

Effects of captopril on fibrinolytic function in healthy humans.

Several lines of evidence point to an interrelation of the renin angiotensin system (RAS) with the endogenous fibrinolytic system. In the present study, we have therefore investigated the effect of the ACE-inhibitor captopril on various parameters of the fibrinolytic system in healthy volunteer subjects. 10 male subjects aged 28-38 years were given captopril 25 mg b.i.d. over 2 weeks. Venous blood was drawn before and at the end of the treatment period at 09.00 AM, after the volunteers had received their last dose of captopril by 07. 30 AM. Blood samples were processed for the determination of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1). Both parameters were determined with respect to their abundance (as antigen concentrations) and function (activity). In addition, the concentration and activity of the von Willebrand factor were also determined. Two weeks of captopril treatment had no significant effect on any of the above mentioned parameters. Our results thus show that short-term treatment with the ACE-inhibitor captopril, at least in healthy subjects on an unrestricted NaCl intake, does not affect the fibrinolytic balance between t-PA and PAI-1 or the von Willebrand factor.

Adult↗
PubMed1998

Antihypertensive drug treatment and fibrinolytic function.

Thromboembolic complications such as ischemic stroke and myocardial infarction are significantly more frequent in patients with arterial hypertension. From the available intervention studies, it appears that pharmacologic treatment of hypertension-at least with diuretics and beta-blockers-may more effectively protect against cerebrovascular as compared to coronary thromboembolic events. Whether other antihypertensive substances provide a more effective protection with respect to cardiac morbidity and mortality is the subject of numerous studies presently underway. These studies will help to answer the question of whether the extent of protection from coronary events during antihypertensive treatment depends on factors beyond blood pressure control. The fibrinolytic system is crucially involved in the pathogenesis of thromboembolic events. One determinant of this system is the balance between plasminogen activators (tissue-type plasminogen activator [t-PA]) and inhibitors (plasminogen activator inhibitor 1 [PAI-1]). Experimental and clinical evidence suggests that at least some of the drugs used in the treatment of hypertension may alter the activity of the fibrinolytic system. Scarce and controversial data with respect to such an interaction exist with respect to diuretics, beta-blockers, and calcium antagonists. In addition, experimental evidence demonstrates that PAI-1 is stimulated by angiotensin II (A II), whereas t-PA is activated by bradykinin. Thus, antihypertensive drugs acting within the renin angiotensin system should exert effects also within the fibrinolytic system. However, results from clinical studies with angiotensin converting enzyme (ACE) inhibitors and A II receptor antagonists do not unequivocally support such a concept. The discrepancy in the results may, at least in part, be explained by studies performed in healthy volunteer subjects showing that ACE inhibition profoundly affected fibrinolysis only during stimulation of the renin angiotensin system by NaCL restriction.

Adrenergic Antagonists↗
PubMed1998

Changes in antihypertensive therapy--the role of adverse effects and compliance.

In a German multicentre study (1603 patients, 320 private practices), adverse effects and patient compliance during antihypertensive therapy were investigated using standardized questionnaires for both patient and physician. Patients with a change in antihypertensive therapy during the last six months were included in this study. The single most important reason for the change in therapy was inadequate blood pressure control (48.4%), followed by adverse effects (30.1%), patient dissatisfaction (20.0%), non-compliance (16.8%) and cost (4.9%). The most frequent adverse effects noted by the doctors were cough (51.9%), oedema (36.9%), flush (36.6) and dizziness (27.8%). In comparing the answers of the physicians and patients, it becomes obvious that compliance may be overestimated by the doctors (good: 41.7%; medium: 57.3%; bad: 1.0%), since only 32.3% of the patients stated that they never missed a dose, 54.8% were occasionally non-compliant and 12.9% admitted missing a dose frequently. The predominant reasons for non-compliance (assessed by the patients) were forgetfulness (40.4%), followed by adverse effects (9.6%) and irregular lifestyle (6.5%). Thus, lack of effectiveness and adverse effects/patient dissatisfaction/non-compliance contributed roughly equally to the decision to change therapy. In addition, forgetfulness was shown to be an important contributor to suboptimal compliance. Lastly, physicians may still underestimate the extent of non-compliance.

Adult↗
PubMed1997

Low-density lipoprotein-induced formation of nitric oxide by cultured vascular smooth muscle cells of the rat.

There is evidence that low-density lipoprotein (LDL) plays a crucial role in atherogenesis. On the cellular level, LDL has been shown to activate a number of mechanisms involved in atherogenesis and vasoconstriction. Local immoderate vasoconstriction is physiologically antagonized by nitric oxide, which is released from the endothelium. To find out whether LDL also influences the synthesis of nitric oxide in vascular smooth muscle cells, both the conversion of arginine to citrulline and the production of nitrite were determined as a measure of nitric oxide formation. After incubation of rat vascular smooth muscle cells with native LDL (25 micrograms mL-1) for 24 h, the production of both L-[14C]-citrulline [39600 (3600) cpm mg-1 cell protein] and nitric oxide [2.95 (0.56) mumol L-1] were about twice and 1.5-fold the amount of the corresponding values in untreated cells (mean +/- SD, P < 0.05, n = 4). Oxidized LDL was less effective than the native form. The presence of the arginine analogue NG-methyl-L-arginine reduced citrulline production dose-dependently but augmented DNA synthesis, both induced by LDL. In addition, the lipoprotein caused a 1.6-fold increase in cyclic GMP production following a 24-h incubation [control = 10.9 (3.8) pmol mg-1 cell protein, P = 0.016]. The results suggest that native LDL might partly impair its atherogenic potential on the vasculature by stimulating the production by smooth muscle cells of both nitric oxide and cyclic GMP.

Animals↗
PubMed1994

In vitro antioxidant activity of calcium antagonists against LDL oxidation compared with alpha-tocopherol.

The dose-dependent (1, 5, 10, 50 microM) antioxidative activity of calcium antagonists (verapamil, diltiazem, nifedipine, amlodipine, isradipine or lacidipine) and alpha-tocopherol against copper-induced LDL (0.25 mg/ml) oxidation was compared by measuring the diene formation and the content of TBARS. For diltiazem no antioxidant effect could be found, whereas the other calcium antagonists and alpha-tocopherol have demonstrated antioxidant activity at least at concentrations of 10 and 50 microM: alpha-tocopherol > lacidipine > nifedipine > isradipine, verapamil, amlodipine. Additionally, alpha-tocopherol and lacidipine were able to attenuate LDL-oxidation significantly at 1 and 5 microM. These results indicate in vitro antioxidative activity of calcium antagonists especially from the dihydropyridine-type with greatest activity for the strongly lipophilic lacidipine. This might be one possible antiatherogenic mechanism of calcium antagonists, since oxidative modification enhances the atherogenic potential of LDL.

Adult↗
PubMed1994

[Overweight in Switzerland. Cross-comparison of various studies with the Heureka Study].

In this study the most important Swiss studies on the incidence of overweight and obesity are summarized and compared to the corresponding prevalence rates from the Heureka study. Interestingly, data on body weight indexes (mostly mass indexes) and the various prevalence rates showed good accordance for younger age groups. In the upper age classes however, phenotypic differences concerning determinants and risk factors for overweight became obvious in the different Swiss populations (i.e. from geographically different regions of Switzerland). Nevertheless, regional risk factors could not been detected because specific data were lacking. The importance of uniform weight definitions for studies as well as for daily practise is stressed.

Adult↗
PubMed1994

Primary aldosteronism: difference in clinical presentation and long-term follow-up between adenoma and bilateral hyperplasia of the adrenal glands.

Since 1974 primary aldosteronism has been diagnosed in 71 patients in our outpatient clinic. Thirty-four patients had a unilateral aldosterone-producing adenoma, whereas bilateral adrenal hyperplasia was diagnosed in 37 patients. Although at the time of diagnosis the mean potassium values were lower and mean aldosterone levels were higher in patients with an adenoma, as compared to those with bilateral hyperplasia, these laboratory data did not allow us to differentiate between the two leading causes of primary aldosteronism in the individual patient due to pronounced overlap of laboratory values between the two groups. During the first few years, a successful differential diagnosis was made by adrenal phlebography and separate sampling of plasma aldosterone in both adrenal veins; later non-invasive imaging techniques such as computed tomography and radionuclide scanning were used. The best results were obtained in patients with adenoma who underwent adrenalectomy. Fifty-six percent of these patients were clinically and biochemically cured; 28% were improved and had normal blood pressure values during drug treatment. In contrast, patients with bilateral hyperplasia were treated pharmacologically, but only in half of the patients could normal blood pressure values be achieved. Two thirds of the male patients developed gynecomastia during spironolactone treatment. As expected, unilateral adrenalectomy was unsuccessful in the 7 patients with bilateral hyperplasia who underwent surgery. Our results confirm that surgical treatment of adrenal adenomas and drug treatment of bilateral hyperplasias are the appropriate therapy in primary aldosteronism. A differential diagnosis cannot be made on the basis of clinical and non-invasive laboratory data alone; imaging techniques have to be included in the diagnostic process.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1994

Ambulatory 24-hour blood pressure versus self-measured blood pressure in pharmacologic trials.

In recent years, indirect ambulatory 24-h blood pressure monitoring and self-measurement at home have gained increasing importance in pharmacologic studies. Both methods have important advantages over conventional casual blood pressure determinations in the clinic. The better reproducibility of blood pressure recordings by either ambulatory monitoring or home readings suggests that both techniques are superior to office readings for evaluating the effect of antihypertensive therapy. The multiple readings obtained during ambulatory 24-h monitoring or by self-measurement at home reduce the variability of blood pressure estimates and substantially decrease the number of patients needed to detect clinically relevant blood pressure differences. Furthermore, dose-response relationships of new and established antihypertensive drugs are improved, as the random effect of blood pressure measurements falls below the expected treatment effect. Although there is some overlap between the information obtained with home and ambulatory monitoring, there are also important differences. Ambulatory monitoring provides information about the diurnal profile of blood pressure and has great advantages for trials investigating the time course of a particular drug. Self-measurement can provide repeated measurements in the same situation over prolonged periods of time, and therefore is ideally suited for monitoring changes in blood pressure induced by treatment or progression of the disease. In pharmacologic studies both techniques are thus complementary.

Adrenergic beta-Antagonists↗
PubMed1994

The Dübendorf Study: a population-based investigation on normal values of blood pressure self-measurement.

There is evidence that self-measurement of BP increases precision, reproducibility and prognostic value of BP measurement. However, generally accepted normal values for BP values obtained by self-measurement are still missing. The present study was undertaken to investigate differences between office and self-measured blood pressure; 503 randomly selected inhabitants (265 men and 238 women, age 20-90 years, mean age 46.5 +/- 12.9 years) of the small town of Dübendorf in Switzerland were studied. The subjects were not preselected according their BP levels, only patients taking antihypertensive drugs were excluded. Self-measurement was performed at home by the subjects during 14 days in the morning between 6 and 8 am and in the evening between 6 and 8 pm (mean of 26.7 measurements). Office BP was taken before and after the two week period. Mean office BP (130.0 +/- 16.5/82.1 +/- 11.1 mmHg) was significantly (P < 0.01) higher than mean self-measured BP (123.1 +/- 14.6/77.6 +/- 10.7 mmHg). There was no significant difference between first and second office BP measurement. Morning self-measured BP was lower than evening pressure (delta 4.0/1.4 mmHg, both P < 0.01) and the mean was taken for comparison with office BP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[The metabolic syndrome: common etiology for distinct cardiovascular risk factors?].

Hypertension, dyslipidemias, glucose intolerance and obesity are among the most important cardiovascular risk factors. There is growing evidence for the concept of a relationship between blood pressure regulation and metabolic changes. The combination of hypertension and the metabolic changes mentioned above has been named metabolic syndrome in the literature. The central role of insulin resistance and consecutive hyperinsulinemia in the metabolic syndrome has been shown in epidemiological, clinical, genetic and animal studies. The metabolic syndrome can be demonstrated in about one half of the hypertensive population. This pathophysiological concept has to be taken into consideration in the therapy and prevention of the different cardiovascular risk factors.

Humans↗
PubMed1993

[Correlation between disorders of lipid metabolism and hypertension in 10,892 participants in the Heureka Study].

UNLABELLED: Hypertension and hyperlipidemia belong to the most important and most frequent cardiovascular risk-factors. It is known that hypertensive patients show hypercholesteremia more often than normotonic persons and some of the mechanisms causing this unfavourable combination seem to be disclosed. METHOD AND RESULTS: During the important Swiss research-exhibition Heureka (april to november 1991) in Zürich, blood pressure (BD), pulse, cholesterol and in 822 probands additionally HDL, were investigated in 11,997 volunteers. Cardiovascular risk-factors were registered by means of a questionnaire. 10,892 completed questionnaires (5973 female, 4919 male probands) could be used for this analysis intended to answer the question whether a relation between blood pressure and cholesterol exists. Stratification and multivariate analysis allowed consideration of certain factors that could possibly influence the results (anthropometry, age). A separate multiple linear regression analysis with cholesterol as dependent variable was made for female and male probands respectively whereby regression coefficients for systolic and diastolic blood pressure values remained significant (p < 0.001). In the highest cholesterol-quintile 36.4% hypertensive probands (in the lowest 6%) were found. Distribution of cholesterol was distinctly different in a group with diastolic blood pressure values < 70 mmHg compared to the group with values > 100 mmHg. Higher diastolic pressures were associated with higher cholesterol values even after stratification in age-classes and diastolic pressure classes. CONCLUSIONS: These results underline the hypothesis, that cholesterol modifies blood pressure. Thus the relevance of a disturbed lipid metabolism for accompanying hypertension seems to be confirmed and an adapted antihypertensive therapy considering all risk factors is proposed as the most successful strategy.

Adolescent↗
PubMed1993

[Are home blood pressure measurements and 24-hour ambulatory recordings superior to office measurements? Comparison of 3 blood pressure recording methods in a study of cilazapril versus atenolol].

Self-assessment of blood pressure and ambulatory blood pressure monitoring (ABPM) are being more widely used in the diagnosis and therapy of hypertension, in addition to office blood pressure measurement. The present multicenter double-blind study compared cilazapril 2.5 to 5 mg (n = 26) to atenolol 50 to 100 mg (n = 27) over a period course of eight weeks. Office blood pressures in the morning before medication, ABPM over 24 h and self assessment of the blood pressure in the morning and evening were taken. The aim of the study was to find out if the results of ABPM and self assessment of blood pressure are similar when compared to office blood pressure measurement. After four weeks of therapy both cilazapril and atenolol achieved a significant and comparable reduction of blood pressure, which did not change significantly afterwards. Both medications showed a comparable blood pressure control over 24 h. with a once-a-day regimen. The comparison of the three techniques of blood pressure measurement demonstrates that ABPM results in significantly lower average daily values than office blood pressure measurement and that the self-assessed blood pressure values in most cases lie in-between. Although the diastolic ambulatory daily values were on the average 9 mmHg lower than the corresponding office values, it was not possible for an individual patient to accurately predict the ambulatory value obtained by to his office blood pressure value. Similar results were found for the values according to self assessment of blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Low density lipoprotein subfractions increase thromboxane formation in endothelial cells.

Correlations between dyslipidemia and high blood pressure have been shown. It is unclear whether there is a causal relationship but there are indications that blood lipids might have a direct effect on mechanisms regulating the vascular tone. As secretory products of endothelial cells (EC) have been suggested to be involved in blood pressure regulation, we studied the influence of low density lipoprotein subfractions on thromboxane (T) synthesis in human umbilical vein endothelial cells (HUVEC). LDL can be separated into at least three major subfractions. In the present study, subfractions LDL1 (d = 1.030-1.033 g/ml), LDL 2 (d = 1.033-1.040 g/ml), and LDL 3 (d = 1.040-1.045 g/ml) were obtained by density gradient ultracentrifugation. T was measured by a radioimmuno-assay. LDL subfractions induced a dose dependent (10-100 micrograms/ml) increase in T synthesis. Control T concentration was 96 +/- 12 pg/ml. LDL 3 (205 +/- 17 pg/ml, p < 0.01) and LDL 2 (194 +/- 13 pg/ml, p < 0.05) caused a significantly higher T concentration compared to the LDL 1 subfraction (152 +/- 11 pg/ml). These results indicate that LDL 2 and 3- the subfractions with the higher density-might have a more pronounced effect on T synthesis by EC than the other LDL subfractions.

Cells, Cultured↗
PubMed1993

Lipoproteins induce expression of the early growth response gene-1 in vascular smooth muscle cells from rat.

Recently, we reported that low-density lipoprotein (LDL) induces in vascular smooth muscle cells (VSMCs) intracellular effects such as an elevation of intracellular free Ca2+ concentration ([Ca2+]i) and intracellular pH (pHi). The early growth response gene-1 (Egr-1) has been identified as a transcription factor belonging to a class of immediate-early genes expressed upon growth, and/or differentiation signals in a large variety of cells and species. Here we show that LDL induces a dose-dependent expression of the Egr-1 mRNA with a maximum at 30 min. Experiments in the presence of the dihydropyridine calcium blocker isradipine suggest that the lipoprotein-induced Egr-1 mRNA induction occurs via a Ca2+ dependent pathway. To demonstrate whether these intracellular responses are only specific to LDL we examined the effects of high- and very low density lipoprotein (HDL and VLDL) on [Ca2+]i and expression of Egr-1 mRNA. The present results show that all lipoproteins induce expression of Egr-1 mRNA and elevation in [Ca2+]i in VSMCs.

Animals↗
PubMed1993

The use of self-measured blood pressure determinations in assessing dynamics of drug compliance in a study with amlodipine once a day, morning versus evening.

OBJECTIVE: To test whether the time of administration influences the therapeutic response to a calcium antagonist taken once a day. Also, the dynamics of drug compliance and its impact on blood pressure control were investigated. DESIGN: Twenty outpatients with mild-to-moderate hypertension were included in a randomized, placebo-controlled open study. In a crossover design, all of the patients received 5 mg amlodipine, either in the morning or in the evening, during two consecutive 4-week treatment periods. METHODS: Blood pressure was taken by casual measurement, ambulatory 24-h monitoring (SpaceLabs 90202) and self-measurement at home, performed with a semi-automatic oscillometric device during the whole study period. Compliance was assessed using the Medication-Event-Monitoring System (MEMS). RESULTS: Neither casual nor ambulatory day- or night-time readings detected a significant difference between morning and evening administration. However, self-measurement documented significantly greater blood pressure reductions for morning than for evening administration. The MEMS showed different compliance on the days of ambulatory monitoring (100% with both drug regimens) compared with the whole treatment period. The number of days with missed medication was thus significantly higher for the evening dosing regimen. The difference in self-measured blood pressure between the two regimens was lost if the days with missed medication were removed from the statistical analysis. CONCLUSIONS: Time of once-a-day amlodipine administration does not influence its efficacy for 24-h blood pressure control. Furthermore, the use of self-measurement and the MEMS may provide useful additional information on the pharmacodynamic impact of different dosing patterns in hypertensive patients.

Adult↗