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Biomedical subjects

T Mengden

Publications and source records attributed to T Mengden.

At least 19 recordsLinked to original sources
PubMed1992

[Acceptance of 24-hour blood pressure determination].

In interviews with 247 patients acceptance and behaviour during 24-hour-ambulatory blood-pressure recording were studied. In contrast to previous assumptions it was shown that the blood-pressure profile was not recorded during normal activities for a great part of patients. Very often the patients reduced their activity over the day. Our results show that for wider distribution and applications of this procedure the measuring devices have to be improved. A substantial part of patients experienced the ambulatory blood-pressure recording as an comfortable, such that one of eight patients declined a further recording and 20% of the patients complained about disturbed sleep.

Activities of Daily Living↗
PubMed1992

Lysolecithin actions on vascular smooth muscle cells.

Oxidation of low density lipoprotein increases its atherogenic potential. During oxidation there is an extensive conversion of lecithin to lysolecithin. In rat aortic smooth muscle cells, 2-25 micrograms/ml lysolecithin elevated cytosolic calcium concentration up to 560%. Lysolecithin (10-20 micrograms/ml) increased [3H]thymidine incorporation from 15 cpm/mg cell protein (controls) up to 189 cpm/mg cell protein. Lysolecithin (10 micrograms/ml) potentiated the PDGF-induced (50 ng/ml) [3H]thymidine incorporation up to 6.3 times. The results indicate that lysolecithin could induce mechanisms, by which oxidized low density lipoproteins could promote cell growth and thus contribute to atherosclerosis.

Animals↗
PubMed1992

[Self measurement of blood pressure: normal and pathological values].

To date, the normal range for self-recorded blood-pressure values has yet to be defined. In this paper possible definitions of the normal range of self-recorded blood pressure are discussed. In large epidemiologic studies self-recorded and casual blood-pressure values should be compared to each other, and in prospective interventional studies blood-pressure values for the initiation of therapy should be defined. Before the termination of these studies we recommend the start of an antihypertensive therapy above 140/90 mmHg. Although definite normal values for self-recorded blood pressure are still missing, a broader use of this method seems to be justified because of the well-known pitfalls of the causal clinical blood-pressure measurement.

Blood Pressure Determination↗
PubMed1992

[Are mercury sphygmomanometers obsolete?].

The measurement of blood pressure during medical visits is limited in its diagnostic, prognostic and therapeutic value by physiologic variability of hypertension and measurement errors. Repeated measurements reduce the effect of spontaneous variations of blood pressure. They allow a more secure assessment of real tension. Regular training for proper technique and elimination of arbitrary preference for rounded last digits or automated recording minimize erroneous measurements. By the multitude of recorded parameters the ambulatory measurement over 24 hours and the self-assessment of blood pressure provide a representative diurnal profile superior to individual measurements at the doctors office. Each of the two methods has its own field of application, although prognostic and therapeutic aims seem similar. The continuous recording over 24 hours is suited for initial assessment and identification of hypertensive patients. Self-assessment of blood pressure has its use for long-term follow up and optimization of therapy. Both methods are complementary and only limited from wider use by lacking internationally accepted normal values and standardization of available devices.

Blood Pressure↗
PubMed1992

[Combination therapy of cardiovascular risk factors].

Risk factors for cardiovascular diseases, which are the leading cause of mortality in the industrialized countries, are well investigated; however, the results of intervention studies on the therapy of single risk factors were disappointing in the past. Recently, there has been growing evidence that there might be a closer pathophysiological relation between arterial hypertension, hypercholesterolemia, obesity, impaired glucose tolerance and genetic disposition than previously thought. For the treatment of the individual patient, this concept requires a complete work-up and comprehensive therapy of all risk factors. The therapy of several mildly elevated risk factors may be more beneficial than a too vigorous reduction of the blood pressure alone. At the beginning of every therapeutic regimen, there has to be a nonpharmacological approach. Diet and weight reduction even in mild obesity are more efficient in influencing several risk factors at the same time than pharmacological therapy. Metabolic consequences of drug treatment have to be carefully monitored.

Cardiovascular Diseases↗
PubMed1992

Urinary free cortisol versus 17-hydroxycorticosteroids: a comparative study of their diagnostic value in Cushing's syndrome.

We evaluated the usefulness of the basal urinary 24-h excretion rates of free cortisol versus 17-hydroxycorticosteroids in the diagnosis of Cushing's syndrome. On an outpatient basis, both urinary free cortisol and 17-hydroxycorticosteroids levels were determined in 48 patients with Cushing's syndrome, as well as in 95 obese and 94 healthy control persons of normal weight. Determination of the urinary free cortisol content allowed a clear-cut distinction between the patients with hypercortisolism and the controls, resulting in a sensitivity of 100% and specificity of 98% for the diagnosis of Cushing's syndrome. The diagnostic accuracy of urinary free cortisol was distinctly superior to that of 17-hydroxycorticosteroids, which showed a wide overlap of values between the groups, with a sensitivity of 73% and a specificity of 94%. In conclusion, the measurement of basal urinary free cortisol provided an excellent diagnostic sensitivity and specificity in the assessment of adrenocortical function. This simple and accurate test thus seems to be particularly useful in the outpatient evaluation of patients with suspected Cushing's syndrome.

17-Hydroxycorticosteroids↗
PubMed1992

Comparison of casual, ambulatory and self-measured blood pressure in a study of nitrendipine vs bisoprolol.

In a double-blind, placebo-controlled study the antihypertensive efficacy and tolerability of a single morning dose of either 10 mg bisoprolol (n = 26) or 20 mg nitrendipine (n = 27) were investigated. Blood pressure was measured by three techniques: (1) Casual blood pressure 24 h after the dose; (2) ambulatory 24-h whole-day monitoring; and (3) self-recorded blood pressure in the morning 24 h after the dose (6-8 a.m.) and in the evening (6-8 p.m.). After 4 weeks of therapy bisoprolol had produced a highly significant reduction in blood pressure as assessed by causal, ambulatory day- and night-time monitoring, and self-measured morning and evening readings. Bisoprolol was significantly more effective than nitrendipine, which did not induce a significant reduction in the ambulatory night-time recordings. Whole-day ambulatory blood pressure profiles showed an antihypertensive effect of bisoprolol throughout the entire 24-h period. 24-h blood pressure curves after nitrendipine demonstrated a markedly shorter duration of action, with no reduction in early morning blood pressure. Adverse effects and tolerability of the two drugs were comparable. The average changes in systolic and diastolic blood pressure after bisoprolol and nitrendipine in 2-h periods of ambulatory monitoring (6-8 a.m. and 6-8 p.m.) and self-measured blood pressure (6-8 a.m. and 6-8 p.m.) showed a good agreement between ambulatory and self-measured blood pressure determinations with no significant difference between the methods. The results show that 24 h antihypertensive efficacy was more pronounced for bisoprolol than for nitrendipine at the doses studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1992

An evaluation of self-measured blood pressure in a study with a calcium-channel antagonist versus a beta-blocker.

In recent years self-measurement of blood pressure at home has gained increasing importance but there have been only a few studies comparing casual, ambulatory, and self-measured blood pressure determinations during a single clinical trial. We therefore compared treatment-induced blood pressure-reductions in a double-blind, placebo-controlled, parallel study design with a single morning dose of either 10 mg bisoprolol (n = 26) or 20 mg nitrendipine (n = 27) with casual blood pressure readings in the morning before the dose, ambulatory 24-h monitoring, and self-recorded measurements in the morning before the dose and in the evening. Mean reductions for systolic and diastolic blood pressure after 4 weeks of therapy were significantly greater for bisoprolol than for nitrendipine. The treatment-induced blood pressure reductions were most pronounced as assessed by casual readings but showed good agreement between casual, ambulatory, and self-measured blood pressure for group comparisons. In some patients, however, marked individual differences between the three methods were observed. Correlation coefficients between ambulatory and self-measured blood pressure were 0.4 for systolic blood pressure (P less than .05) and 0.6 for diastolic blood pressure (P less than .0005). Under the conditions of this parallel study design and the usual statistical risks, a difference of 5 mm Hg in diastolic blood pressure can be detected in 118 patients at the clinic, in 70 patients if ambulatory blood pressure is used, or in 56 patients if self-measured blood pressure is used. In conclusion, bisoprolol was more effective over 24 h than nitrendipine at the doses studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Oxidized low-density lipoproteins in atherogenesis: possible mechanisms of action.

The increased atherogenic potential of oxidized low-density lipoprotein (ox-LDL) is well documented. In the present study, we investigated possible mechanisms of action of the difference to native LDL. In vitro oxidation of LDL was determined by measurement of thiobarbituric acid-reacting substances and absorption at 234 nm. Copper (5 mumol/L) induced significant (p less than 0.01) oxidation in vitro. Furthermore, LDL isolated from atherosclerotic patients was slightly but significantly (p less than 0.05) more oxidized than LDL from normal controls (2.81 +/- 0.08 vs. 3.21 +/- 0.16 nmol of TBARS/mg of LDL protein). Ox-LDL caused significantly (p less than 0.01) more pronounced contractions of rat aortic rings in vitro compared to nonoxidized LDL expressed as a percentage of maximal contractions induced by 40 mmol/L of KCl (29.0 +/- 5.4% vs. 61.1 +/- 7.2%). Lysolecithin, which is a principal component of ox-LDL formed during oxidation, induced a dose-dependent increase in intracellular free calcium in vascular smooth muscle cells cultured from rat aorta. Doses from 2-25 micrograms/ml were tested and caused a maximum increase of more than 500% (25 micrograms/ml). In conclusion, this study provides further evidence for a higher biological activity of ox-LDL. Lysolecithin might be one of the active components formed during oxidation of LDL.

Animals↗
PubMed1992

Oxidation of low density lipoprotein enhances its potential to increase intracellular free calcium concentration in vascular smooth muscle cells.

There have been suggestions that oxidation of low density lipoproteins (LDL) might increase their atherogenic potential. Because changes in intracellular free calcium concentration [Ca2+]i have been linked to atherogenesis, we compared the influence of oxidized LDL (Ox-LDL) and native LDL (N-LDL) on [Ca2+]i in vascular smooth muscle cells cultured from rat aortas. For determination of [Ca2+]i, fura-2 fluorescence was used. LDL was isolated by ultracentrifugation from the sera of human donors (n = 17). In N-LDL, oxidation was prevented by addition of antioxidants, whereas Ox-LDL was obtained by auto-oxidation. The extent of oxidation was assessed by measurement of thiobarbituric acid-reactive substances. Addition of Ox-LDL (20 micrograms protein/ml) to the vascular smooth muscle cells induced a mean increase of 129 +/- 13% in [Ca2+]i compared with 81 +/- 7% with N-LDL (p less than 0.01). Dose-response curves from 1 to 20 micrograms/ml (six experiments) confirmed this difference within the entire dose range. These results indicate that a more pronounced increase in [Ca2+]i induced by Ox-LDL might be one of the cellular mechanisms responsible for the higher atherogenic potential of Ox-LDL compared with N-LDL, as [Ca2+]i is an important second-messenger system involved in many atherogenic processes such as hypertrophy, cell migration, and cell damage.

Animals↗
PubMed1992

Betablocking drugs in essential hypertension: transdermal bupranolol compared with oral metoprolol.

In the present study the antihypertensive efficacy and tolerability of transdermal bupranolol (30 mg once-daily) was compared with oral metoprolol (100 mg once-daily). Blood pressure measurements were performed in the office, at home, and with ambulatory 24-h blood pressure devices. Systemic and local side-effects, as well as compliance and acceptance, were evaluated every two weeks. The treatment period lasted eight weeks. The results showed a significant decrease in blood pressure under the bupranolol transdermal therapeutic system in the office, at home, and with 24-h blood pressure measurements day- (08h00-20h00) and night-time (20h00-08h00). Under oral metoprolol there was a significant blood pressure decrease in the office, at home, and in the mean daytime values of the 24-h blood pressure measurements. The night-time values, however, demonstrated only a slight decrease in blood pressure, being significant only for diastolic values. Systemic side-effects were comparable in both groups. 69% of the patients had local side-effects at the patch side (erythema, papulous exanthema, pruritus). Six patients dropped out because of localized urticarial exanthema (five patients treated with transdermal bupranolol, one patient treated with oral metoprolol). In comparison to the oral form, twice as many patients had admitted to have been non-compliant with the patches (13 versus 7 patients). At the end of the study, 24 out of 32 patients preferred to be treated with capsules.

Administration, Cutaneous↗
PubMed1991

[Performing self-measurement of blood pressure: a patient survey].

In the present study the knowledge of 200 patients of our hypertension clinic about the technique of blood-pressure self-measurement was investigated using a questionnaire of 22 questions. 44-66% of the patients in different age groups measured their own blood-pressure, showing that self-measurement is commonly used, regardless of the age. 73% of the patients had bought a device on their own, but only 17% on the physician's advice. Possible causes for erroneous measurements were rarely known and underestimated by the patients. Due to lacking or insufficient instruction a relatively high percentage of the patients did not perform correct measurements. 45% did not measure the blood-pressure at the same time of day, 45% did not read systolic and diastolic pressures to the nearest 2 mmHg mark of the manometer scale, 59% did not count the pulse rate and 52% did not document the blood-pressure values. About half of the patients adjusted their medication on the ground of self-measured blood-pressure determinations. 45% of the elderly patients felt that their compliance had improved by self-measurement in contrast to 17% in the younger group. Given the increasing use of blood-pressure self-measurement we conclude that education of patients and physicians on possibilities and limitations of self-measurement as well as optimal training in the correct technique seem advisable.

Adult↗
PubMed1991

[How reliable is conventional blood pressure registration? Comparison with a semi-automatic device].

The aim of the present study was to determine observer error in measuring blood pressure by the conventional auscultatory method. Casual blood pressure was measured in two age-matched groups of normo- and hypertensive patients with a conventional mercury sphygmomanometer (n = 181) or a semiautomatic device (n = 176) by ten doctors of the university hospital. Although there were no significant differences in mean systolic or diastolic blood pressure values between the groups, the conventionally determined values showed a distinctively different pattern of distribution in comparison to the semiautomatically taken readings. With conventional readings a highly significant preference for terminal digit "0" (44%) and fewer systolic and diastolic values in the lower blood pressure range were observed. Furthermore there was a higher frequency of conventional readings ending in "8" than in "2". Terminal digit preference in the whole group was mainly due to the doctors, who did not measure blood pressure to the nearest 2 mmHg mark. Our results thus stress the importance of better and regular training in the correct technique of measuring blood pressure in order to reduce sources of observer bias.

Automation↗