PubMed Health⌕ Search

Biomedical subjects

E Hoberg

Publications and source records attributed to E Hoberg.

At least 19 recordsLinked to original sources

Pharmacological activities of Vitex agnus-castus extracts in vitro.

The pharmacological effects of ethanolic Vitex agnus-castus fruit-extracts (especially Ze 440) and various extract fractions of different polarities were evaluated both by radioligand binding studies and by superfusion experiments. A relative potent binding inhibition was observed for dopamine D2 and opioid (micro and kappa subtype) receptors with IC50 values of the native extract between 20 and 70 mg/mL. Binding, neither to the histamine H1, benzodiazepine and OFQ receptor, nor to the binding-site of the serotonin (5-HT) transporter, was significantly inhibited. The lipophilic fractions contained the diterpenes rotun-difuran and 6beta,7beta-diacetoxy-13-hydroxy-labda-8,14-dien . They exhibited inhibitory actions on dopamine D2 receptor binding. While binding inhibition to mu and kappa opioid receptors was most pronounced in lipophilic fractions, binding to delta opioid receptors was inhibited mainly by a aqueous fraction. Standardised Ze 440 extracts of different batches were of constant pharmacological quality according to their potential to inhibit the binding to D2 receptors. In superfusion experiments, the aqueous fraction of a methanolic extract inhibited the release of acetylcholine in a concentration-dependent manner. In addition, the potent D2 receptor antagonist spiperone antagonised the effect of the extract suggesting a dopaminergic action mediated by D2 receptor activation. Our results indicate a dopaminergic effect of Vitex agnus-castus extracts and suggest additional pharmacological actions via opioid receptors.

Animals↗

Quantitative high performance liquid chromatographic analysis of diterpenoids in agni-casti fructus.

Pharmacological data have indicated that part of the dopaminergic activity of Vitex agnus-castus is attributed to the labdan diterpenoids found in the fruits. Therefore an analytical method for the standardization of rotundifuran (1), vitexilactone (2) and 6 beta,7 beta-diacetoxy-13-hydroxy-labda-8,14-diene (3) was developed. Because of the time-consuming and expensive isolation of the diterpenoids, p-cymene was chosen as an internal standard. The concentration of rotundifuran in different extracts and trade samples of the drug varies between 0.04 and 0.30% in the drug and between 1.04 and 2.23% in the extract. The concentration of vitexilactone was generally lower between 0.016 and 0.167% for the drug and between 0.34 and 1.01% for the extract. The determined concentration of 6 beta,7 beta-diacetoxy-13-hydroxy-labda-8,14-diene in the drug was in the range of 0.02 and 0.10% and in the extract in the range of 0.18 and 0.80%. Determination of the factors of correction of p-cymene gave 5.63 for rotundifuran, 2.73 for vitexilactone and 3.74 for 6 beta,7 beta-diacetoxy-13-hydroxy-labda-8,14-diene.

Chromatography, High Pressure Liquid↗

Comparison of two sample preparation techniques for sniffing experiments with broccoli (Brassica oleracea var. italica Plenck).

The suitability of the headspace solid phase microextraction (HSSPME) for gas chromatography-olfactometry (GC-O) with aroma extract dilution analysis in comparison to the dynamic head space sampling on a Tenax trap was tested exemplarily by the aroma volatiles of fresh broccoli. A high number of odour sensations in qualitative olfactometry was registered with both sample preparation techniques. The key aroma compounds of the fresh broccoli material are represented by high flavour dilution factors with dynamic head space sampling and headspace SPME. The SPME method has found to be a convenient and fast technique suitable especially for qualitative GC-O. The adsorption selectivity of the fiber and the substance discrimination have to be taken into account for quantitative use like aroma extract dilution analysis.

Brassica↗

[Psychological comorbidity in patients with alarming chest pain symptoms].

About 1/3 of patients with chest pain undergoing coronary arteriography (CA) have no coronary artery disease (CAD). Individuals with non-CAD chest pain may be younger and more likely to be female; they may express higher degrees of neuroticism. Are those features stable enough to justifi; exclusion from CA if present? To investigate this issue, data on psychodiagnostic parameters (depression, anxiety, somatic complaints) were obtained in patients before this were referred to CA. Inclusion criteria were a chief complaint of chest pain with episodes of angina-like pain at rest, suspicious enough to warrant cardiac catherisation; and no prior history of CAD or other organic heart disease. The sample consisted of 77 patients, recruited from 89 eligible patients. 12 patients were excluded because CA findings were missing for multiple reasons. CA was conducted by Judkins technique. Patients were labeled as CAD (-) if no stenosis were detectable. In 50 (65%) of cases CA findings were positive and in 27 (35%) findings were negative. CAD+ were significantly older (p < 0.05); the superiority in both groups were male. Prevalence of emotional disorders was markedly more pronounced in both groups in comparison to the normal population and to a group of male myocardial infarction survivors. However, those features did not discriminate between the groups. Long acting chest pain was predictive for high degrees of emotional disability (relative risk 5.33; 95% Kl 1.6-61.6; p < 0.012). Chest pain at rest is a major source of anxiety, depression and subsequent somatic preoccupation despite its ischaemic or functional origin. It leads to clinically relevant adjustment disorders in a significant proportion of chest pain patients and triggers emotional disstress. These factors may thus have less impact on risk stratification than expected.

Adult↗

The effects of calcium antagonists after PTCA.

Experiments have shown that calcium antagonists can prevent restenosis after coronary angioplasty. The first controlled clinical trials, however, failed to show such a benefit after PCTA: the recurrence rate was not significantly influenced by either nifedipine (10 mg q.i.d.) or diltiazem (90 mg t.i.d.). Another trial used a higher dose of diltiazem (mean 329 mg per day) in a larger number of patients, but again the result was negative. In contrast, diltiazem 180 mg per day was reported more recently to significantly reduce restenosis, and high-dose verapamil treatment was similarly successful in a subgroup of patients with stable angina pectoris at the time of primary successful PCTA. Despite some important limitations of the five monocentre trials, the combined analysis of the results shows that calcium antagonists have a beneficial effect on restenosis rate after PTCA. Whether this effect is limited to heart rate slowing substances and to special subgroups of lesions has to be clarified by further studies in sufficiently large patient populations.

Angioplasty, Balloon, Coronary↗

[Calcium antagonists and prevention of post-angioplasty restenosis].

Five randomised double blind clinical trials have assessed the effects of long term therapy with calcium antagonists on post-coronary angioplasty restenosis. Nifedipine 40 mg/day was tested in 241 patients by Whitworth et al: there was no difference in the incidence of restenosis between the treatment and placebo groups. Corcos et al studied the effects of diltiazem 270 mg/day in 92 patients: there was no significant difference between the two groups. In a study of 201 patients, O'Keefe et al found no significant difference in incidence of restenosis in a group treated with diltiazem (240 to 360 mg/day) compared with placebo. The fourth trial, conducted by Unverdorben et al, not yet fully published, in 170 patients, showed a significant reduction in restenosis in patients treated with diltiazem 180 mg/day (p = 0.03). Finally, the VAS trial (Verapamil Angioplasty Study) showed high dose verapamil (480 mg/day) to reduce the incidence of restenosis in a subgroup of patients with stable angina and high risk of restenosis.

Angioplasty, Balloon, Coronary↗

Verapamil treatment after coronary angioplasty in patients at high risk of recurrent stenosis.

OBJECTIVE: To evaluate the efficacy of high-dose verapamil treatment (240 mg twice daily) in the prevention of angiographic restenosis after primary successful coronary angioplasty in patients at high risk of recurrent obstruction. DESIGN: A placebo controlled, double blind trial in which patients with stable angina pectoris and patients with unstable angina or non-Q wave infarction treated with 330 mg aspirin and 75 mg dipyridamole twice daily were randomised to a verapamil group or a control group. Follow up angiography was performed 6 months after angioplasty or sooner if signs of recurrent ischaemia developed. SETTING: University department of cardiology. PATIENTS: 196 consecutive patients undergoing coronary angioplasty from the beginning of April 1987 to the end of March 1989 and meeting the selection criteria that included the presence of at least one of six predefined risk factors for restenosis. At the time of coronary angioplasty 113 patients had unstable angina or non-Q wave infarction and 83 had stable angina pectoris. RESULTS: In 89 (91%) patients in the verapamil group and in 83 (85%) control patients follow up angiograms were available. The restenosis rate was lower in the verapamil group (48.3%) than in the placebo group (62.7%) (odds ratio 0.56, 95% confidence interval (CI) 0.303 to 1.025 p = 0.059). Of the 172 patients in whom follow up angiograms were available, 24 (13 taking verapamil and 11 taking placebo) did not comply with the trial for more than 40 (34) days (mean (1 SD)). For the remaining 148 patients the restenosis rate was 47.4% in the verapamil group and 63.9% in the placebo group (odds ratio 0.52, 95% CI 0.271 to 0.993, p = 0.046). In the 97 patients with unstable angina or non-Q wave infarction the restenosis rate was not significantly influenced by verapamil (55.8% with verapamil v 62.2% with placebo, odds ratio 0.77, 95% CI 0.339 to 1.728, p = 0.520). In the 75 patients with stable angina pectoris the restenosis rate dropped from 63.2% with placebo to 37.8% with verapamil (odds ratio 0.36, 95% CI 0.137 to 0.917, p = 0.038). CONCLUSION: The observed beneficial effect of high-dose verapamil treatment on the angiographic restenosis rate in patients with stable angina pectoris and at increased risk of recurrent obstruction requires confirmation in further prospective studies.

Aged↗

Regular physical exercise and low-fat diet. Effects on progression of coronary artery disease.

BACKGROUND: Significant regression of coronary and femoral atherosclerotic lesions has been documented by angiographic studies using aggressive lipid-lowering treatment. This study tested the applicability and effects of intensive physical exercise and low-fat diet on coronary morphology and myocardial perfusion in nonselected patients with stable angina pectoris. METHODS AND RESULTS: Patients were recruited after routine coronary angiography for stable angina pectoris; they were randomized to an intervention group (n = 56) and a control group on "usual care" (n = 57). Treatment comprised intensive physical exercise in group training sessions (minimum, 2 hr/wk), daily home exercise periods (20 min/d), and low-fat, low-cholesterol diet (American Heart Association recommendation, phase 3). No lipid-lowering agents were prescribed. After 12 months of participation, repeat coronary angiography was performed; relative and minimal diameter reductions of coronary lesions were measured by digital image processing. Change in myocardial perfusion was assessed by 201Tl scintigraphy. In patients participating in the intervention group, body weight decreased by 5% (p less than 0.001), total cholesterol by 10% (p less than 0.001), and triglycerides by 24% (p less than 0.001); high density lipoproteins increased by 3% (p = NS). Physical work capacity improved by 23% (p less than 0.0001), and myocardial oxygen consumption, as estimated from maximal rate-pressure product, by 10% (p less than 0.05). Stress-induced myocardial ischemia decreased concurrently, indicating improvement of myocardial perfusion. Based on minimal lesion diameter, progression of coronary lesions was noted in nine patients (23%), no change in 18 patients (45%), and regression in 13 patients (32%). In the control group, metabolic and hemodynamic variables remained essentially unchanged, whereas progression of coronary lesions was noted in 25 patients (48%), no change in 18 patients (35%), and regression in nine patients (17%). These changes were significantly different from the intervention group (p less than 0.05). CONCLUSIONS: In patients participating in regular physical exercise and low-fat diet, coronary artery disease progresses at a slower pace compared with a control group on usual care.

Adult↗

[Therapeutic possibilities, respective implications in silent ischemia].

In principle, all forms of treatment applied in patients with symptomatic coronary heart disease may likewise be used in silent myocardial ischemia. Based on Bayes' theorem, therapeutic measures may only be applied in patients with a positive exercise ECG with a high likelihood of coronary heart disease, and/or with myocardial ischemia revealed by another, ECG-independent method, such as, for example, thallium-scintigraphy. As symptomatic improvement cannot be expected in patients with silent myocardial ischemia, therapeutic efficacy can only be documented by an improvement in prognosis. Results of controlled randomized trials are not available in silent myocardial ischemia; therapeutic recommendations can, therefore, only be based on analogous results obtained in patients with symptomatic forms of the disease. Apart from reduction of the known risk factors of coronary heart disease, aspirin may be given to all patients at risk. Among the antiischemic antianginal drugs, beta-receptor blocking agents without intrinsic-sympathomimetic activity may be expected to improve prognosis. In asymptomatic patients with left-stem stenosis and three-vessel disease with impaired left-ventricular function (also, in two-vessel disease with a stenotic dominant LAD) aorto-coronary bypass surgery may be considered in order to improve prognosis.

Adrenergic beta-Antagonists↗

[The noninvasive diagnosis of coronary heart disease in women. The exercise ECG or ST-segment analysis in the long-term ECG?].

The diagnostic value of an exercise ECG in women with the clinical symptoms of stable angina is limited because of its low accuracy in demonstrating coronary heart disease. A study of ambulatory patients was undertaken, involving 143 men and 29 women (mean age 55 [37-70] years), to determine whether ST-segment analysis of the 24-hour ECG gives better results, the coronary arteriogram providing the standard of comparison. 24-hour monitoring and the exercise ECG gave similar diagnostic results (66% vs 67%) in the 143 men. But in the 29 women 24-hour monitoring was diagnostically superior to the exercise ECG (76% vs 45%; P less than 0.01), as a result of a significantly higher specificity (64% vs 29%; P less than 0.05) and a tendency towards higher sensitivity (87% vs 60%; P = 0.13). As expected, the accuracy of the exercise ECG was thus lower in women than in men (P less than 0.05). There were no significant gender-specific differences for accuracy of 24-hour monitoring (76% in women, 66% in men; P less than 0.15). These data indicate that in women ST-segment analysis of the 24-hour ECG is better than the exercise ECG for demonstrating coronary heart disease.

Angina Pectoris↗

Increased plasma viscosity and erythrocyte aggregation: indicators of an unfavourable clinical outcome in patients with unstable angina pectoris.

OBJECTIVE: To determine the prognostic significance of altered plasma viscosity and erythrocyte aggregation in unstable angina. DESIGN: A prospective study of 96 consecutive patients with unstable angina allocated to one of two groups according to predefined threshold values for plasma viscosity and erythrocyte aggregation at study entry. The patients received a standardised treatment and were followed up for six months or until angioplasty or bypass surgery. MAIN OUTCOME MEASURE: Frequency of myocardial infarction. RESULTS: Myocardial infarctions occurred in 7/26 patients with a plasma viscosity greater than or equal to 1.38 mPa s and in 8/35 with a rate constant of erythrocyte aggregate formation greater than or equal to 0.5 mPa (corrected for plasma viscosity) but in only 4/70 with a plasma viscosity less than 1.38 mPa s and in 3/61 with an erythrocyte aggregation less than 0.5 mPa (odds ratios: 6.1 (95% confidence interval 1.3 to 31), p = 0.008, and 5.7 (95% CI 1.2 to 35), p = 0.016). Plasma viscosity and erythrocyte aggregation were more predictive of myocardial infarction than age, male gender, fibrinogen concentration, ST segment abnormalities, or coronary score. Furthermore, Holter monitoring with ST segment analysis showed that ischaemic episodes were more common in patients in whom the rate constant of erythrocyte aggregate formation was greater than 0.5 mPa (15/27 v 17/50, p = 0.029). Cardiac troponin T release was increased in patients with a plasma viscosity of greater than 1.38 mPa s (10/26 v 9/70, p = 0.010). CONCLUSIONS: In patients with unstable angina a considerable increase in plasma viscosity and erythrocyte aggregation identified a subgroup of patients at a high risk of acute myocardial infarction in whom medical treatment was likely to be unsuccessful.

Aged↗

Prevention of restenosis after PTCA: role of calcium antagonists.

The recurrence of coronary obstruction after initially successful percutaneous transluminal coronary angioplasty (PTCA) represents a major problem of this interventional procedure at present. In the pathogenesis of restenosis the growth factor-dependent proliferation and migration of medial smooth muscle cells into the intima of the vessel wall may play a very important role. In experimental studies this process could be inhibited by calcium antagonists. However, the first two placebo-controlled clinical trials showed disappointing results: the restenosis rate was not decreased by the treatment with 10 mg of nifedipine four times daily or by the treatment with 90 mg of diltiazem three times daily. The influence of high-dose verapamil treatment [Isoptin RR (240 mg) twice daily] on the recurrence of coronary stenosis has been investigated by a recently completed double-blind, placebo-controlled trial, the verapamil angioplasty study (VAS). The VAS included 196 consecutive patients with at least one risk factor for restenosis after successful PTCA for stable angina pectoris (n = 75) or unstable angina pectoris/non-Q-wave infarction (n = 97). Eighty-eight percent of the patients underwent follow-up angiography at 4.3 +/- 2.3 months. The publication of detailed data of the VAS including restenosis rates in both clinical subgroups is being prepared.

Aged↗

Calcium-antagonists in preventing restenosis following coronary angioplasty.

In experimental studies the growth factor dependent proliferation and migration of medical smooth muscle cells was found to be inhibited by calcium-antagonists. Since this process seems to play an important role in the pathogenesis of recurrent stenosis, clinical trials were performed to evaluate the influence of calcium-channel blockers on restenosis rate after initially successful coronary angioplasty. However, according to the first 3 completed studies the restenosis rate was not decreased significantly either by the treatment with nifedipine or by the treatment with different dosages of diltiazem. The influence of high-dose verapamil treatment (Isoptin RR, 240 mg verapamil, twice daily) on the recurrence of coronary obstruction has been investigated by a recently completed prospective double-blind, placebo-controlled trial (VAS) which included 196 consecutive patients with at least one risk factor for restenosis. Patients with stable angina pectoris (n 75) and patients with unstable angina/non Q-wave infarction (n 97) were randomized separately. Follow-up angiography within 6 months after the procedure was performed in 88% of the recruited patients. Another 22 patients (11%) stopped the study medication before control angiography. At present, detailed data of the intention-to-treat analysis and the as-treated analysis of the results of VAS were submitted for publication.

Angioplasty, Balloon, Coronary↗

Diagnostic value of ambulatory Holter monitoring for the detection of coronary artery disease in patients with variable threshold angina pectoris.

Patients with chronic stable angina pectoris may present with either fixed or variable threshold symptoms. To evaluate the diagnostic value of ambulatory Holter monitoring for the detection of coronary artery disease (CAD) in patients with variable threshold angina, 216 consecutive candidates for coronary angiography were investigated prospectively. For comparison, a group of 55 consecutive patients with fixed threshold angina was studied under the same conditions. Patients with prior myocardial infarction or angiographically documented CAD were excluded. Within 4 months of Holter monitoring, the advised coronary angiography was performed in 77% of the patients with variable threshold angina and in 89% of the patients with fixed threshold angina (p less than 0.05). The prevalence of CAD was markedly lower in patients with variable threshold angina compared to patients with fixed threshold angina (54 vs 90%, p less than 0.001). CAD patients of both subgroups, however, did not differ significantly with respect to the number of obstructed vessels, the Gensini coronary score, the number with impaired left ventricular function (ejection fraction less than 50%) or the duration of ischemic episodes during Holter monitoring. Diagnostic accuracy of Holter monitoring did not differ between variable and fixed threshold angina groups (67 vs 78%). In 91% of the patients results obtained by Holter monitoring could be compared to the results of a bicycle stress test. In patients with fixed threshold angina the diagnostic accuracy was similar for both tests (80 vs 80%). In patients with variable threshold angina, the diagnostic accuracy of Holter monitoring exceeded that of the exercise stress test (68 vs 55%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗

Silent myocardial ischemia as a potential link between lack of premonitoring symptoms and increased risk of cardiac arrest during physical stress.

The risk of cardiac arrest is increased during strenuous physical exercise in patients with stable coronary artery disease (CAD). Because premonitoring symptoms are rarely observed, silent myocardial ischemia may represent the pathophysiological basis for the induction of malignant ventricular arrhythmias. Holter monitoring was, therefore, performed in 40 consecutive patients entering a randomized intervention trial on progression of CAD. In 20 of 21 participants (95%) in the intervention program greater than or equal to 1 episode of silent myocardial ischemia was observed during the initial training session. The mean duration of silent myocardial ischemia per patient was 25 +/- 13 min/hr of training session. During normal daily activity only 5 patients (24%) experienced greater than or equal to 1 episode of silent myocardial ischemia (p less than 0.001) yielding a mean duration of 0.6 +/- 1.3 minutes of silent myocardial ischemia/hr of ordinary activity per patient (p less than 0.001 vs training session). During a control period of 24 hours without exercise training the incidence (33%) and mean duration of silent myocardial ischemia (0.8 +/- 2.1 min/hr/patient) were similar to those during normal daily activity on the day of the training session. During the training session the occurrence of frequent or repetitive ventricular arrhythmias was related to 10 silent myocardial ischemia episodes detected in 5 patients. During normal daily activity in 1 patient only was the onset of malignant ventricular arrhythmias associated with silent myocardial ischemia (p less than 0.05). Conditions and results of the Holter studies in the control group patients were comparable to those of the patients in the intervention group on the day without physical exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗

[Validation of trend-supported ST segment analysis of long-term ECG recordings].

Trend recordings of relative ST-segment deviations represent a useful tool for the identification of ischemia-like episodes during Holter monitoring. For the generation of trend recordings beat-to-beat data are filtered. The influence of the time constant of the filter on the sensitivity and the specificity for the detection of ischemia-like ECG changes is unknown, however. Ischemia-like episodes were, therefore, simulated and recorded by a frequency modulated Holter recorder and by a conventional six-channel ECG system. Relative ST-segment deviations were filtered using a time constant of 8, 16, 32 or 64 s, or an arithmetic averaging over 9 s for the generation of ST-segment trends. The magnitude of short-lasting ST-segment deviations was underestimated, when beat-to-beat data were filtered using time constants of greater than or equal to 32 s. The influence of posture-related ECG changes on the ST-segment trends was investigated by recording lead CM5 in 14 consecutive patients in different positions by a conventional ECG system. Four out of the 14 patients developed ST-segment elevations greater than or equal to 0.1 mV during leftsided position. Only in these four patients were ST-segment deviations of similar magnitude recorded during the following Holter monitoring. The posture-related ST-segment changes were characterized by an abrupt onset and an abrupt end, resulting in a box-like shape which enabled their correct identification in the ST-segment trend analysis. In order to determine the relative frequency of posture-related ST-segment changes, 35 patients with coronary artery disease (CAD) and 35 patients without underwent Holter monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗