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Biomedical subjects

B Meier

Publications and source records attributed to B Meier.

At least 19 recordsLinked to original sources
PubMed2006

Sex differences in semantic processing: event-related brain potentials distinguish between lower and higher order semantic analysis during word reading.

Behavioral studies suggest that women and men differ in the strategic elaboration of verbally encoded information especially in the absence of external task demand. However, measuring such covert processing requires other than behavioral data. The present study used event-related potentials to compare sexes in lower and higher order semantic processing during the passive reading of semantically related and unrelated word pairs. Women and men showed the same early context effect in the P1-N1 transition period. This finding indicates that the initial lexical-semantic access is similar in men and women. In contrast, sexes differed in higher order semantic processing. Women showed an earlier and longer lasting context effect in the N400 accompanied by larger signal strength in temporal networks similarly recruited by men and women. The results suggest that women spontaneously conduct a deeper semantic analysis. This leads to faster processing of related words in the active neural networks as reflected in a shorter stability of the N400 map in women. Taken together, the findings demonstrate that there is a selective sex difference in the controlled semantic analysis during passive word reading that is not reflected in different functional organization but in the depth of processing.

Adult↗
PubMed2005

Efficacy of drug eluting stents in patients with and without diabetes mellitus: indirect comparison of controlled trials.

OBJECTIVE: To examine whether polymer based coronary stents eluting sirolimus or paclitaxel are equally effective in patients with and without diabetes. METHODS: Systematic review and meta-analysis by indirect comparison of randomised controlled trials comparing stents eluting sirolimus or paclitaxel with conventional bare metal stents. The overall study population and patients with and without diabetes were analysed separately by using the ratio of incidence rate ratios (RIRR). RESULTS: The analysis was based on 10 trials (six with sirolimus, four with paclitaxel), 4513 patients (1146 patients with diabetes), 5755 years of follow up, and 2464 events. In patients without diabetes sirolimus eluting stents were superior to paclitaxel eluting stents with respect to in-stent (RIRR 0.21, 95% confidence interval (CI) 0.10 to 0.48, p < 0.001) and in-segment restenosis (RIRR 0.47, 95% CI 0.24 to 0.92, p = 0.027), target lesion revascularisation (RIRR 0.54, 95% CI 0.30 to 0.99, p = 0.045), and major adverse cardiac events (RIRR 0.46, 95% CI 0.26 to 0.83, p = 0.010). In patients with diabetes the two drug eluting stents did not differ significantly in any of these end points. Meta-regression analysis showed a significant difference between patients with and without diabetes (tests for interaction for in-stent and in-segment restenosis, p = 0.036 and p = 0.016). CONCLUSION: Indirect evidence indicates that sirolimus eluting stents are superior to paclitaxel eluting stents in patients without diabetes but not in patients with diabetes.

Blood Vessel Prosthesis↗
PubMed2005

Prevalence and size of directly detected patent foramen ovale in migraine with aura.

BACKGROUND: Transcranial contrast Doppler studies have shown an increased prevalence of right-to-left shunts in patients with migraine with aura compared with controls. The anatomy and size of these right-to-left shunts have never been directly assessed. METHODS: In a cross-sectional case-control study, the authors performed transesophageal contrast echocardiography in 93 consecutive patients with migraine with aura and 93 healthy controls. RESULTS: A patent foramen ovale was present in 44 (47% [95% CI 37 to 58%]) patients with migraine with aura and 16 (17% [95% CI 10 to 26%]) control subjects (OR 4.56 [95% CI 1.97 to 10.57]; p < 0.001). A small shunt was equally prevalent in migraineurs (10% [95% CI 5 to 18%]) and controls (10% [95% CI 5 to 18%]), but a moderate-sized or large shunt was found more often in the migraine group (38% [95% CI 28 to 48%] vs 8% [95% CI 2 to 13%] in controls; p < 0.001). The presence of more than a small shunt increased the odds of having migraine with aura 7.78-fold (95% CI 2.53 to 29.30; p < 0.001). Besides patent foramen ovale prevalence and shunt size, no other echocardiographic differences were found between the study groups. Headache and baseline characteristics did not differ in migraine patients with and without shunt. CONCLUSIONS: Nearly half of all patients with migraine with aura have a right-to-left shunt due to a patent foramen ovale. Shunt size is larger in migraineurs than controls. The clinical presentation of migraine is identical in patients with and without a patent foramen ovale.

Adult↗
PubMed2005

Aldosterone inhibits uncoupling protein-1, induces insulin resistance, and stimulates proinflammatory adipokines in adipocytes.

Aldosterone is a mineralocorticoid hormone that regulates blood pressure and salt/water balance. Increased aldosterone levels are found in states of disturbed energy balance such as the metabolic syndrome. Adipose tissue has been recognized to play a pivotal role in the regulation of energy homeostasis. We investigated direct aldosterone effects on brown adipocyte function. Aldosterone dose-dependently inhibited expression of uncoupling protein-1 (UCP-1) by 30% (p < 0.01). Furthermore, aldosterone dose-dependently impaired insulin-induced glucose uptake by about 25% (p < 0.01). On a transcriptional level, mRNA of the proinflammatory adipokines leptin and monocyte chemoattractant protein-1 (MCP-1) was increased by 5,000% and 40%, respectively, by aldosterone exposure (p < 0.05). This study demonstrates that aldosterone directly impacts on major adipose functions including stimulation of proinflammatory adipokines.

Adipocytes↗
PubMed2005

The effect of genotype and cultivation method on the total salicylate yield of dark-leaved willows (Salix myrsinifolia).

Ten clones of dark-leaved willows ( Salix myrsinifolia Salisb.) were grown for two years on two different sites, Luikonlahti and Punkaharju, using various combinations of soil cultivation, fertilization and mulch treatments, with the objective of comparing the effect of different cultivation methods on the growth and total salicylate yield. In cultivated soil, the total salicylate yield ranged from 20 to 220 kg/ha, depending on the clone and cultivation method. The use of black polythene mulch and the addition of mineral fertilizer reduced the total salicylate concentrations of several clones. On the other hand, polythene mulch noticeably increased the hectare yield of total salicylates by promoting biomass accumulation.

Agriculture↗
PubMed2005

Influence of diabetes mellitus on coronary collateral flow: an answer to an old controversy.

OBJECTIVES: To determine the influence of diabetes mellitus on coronary collateral flow by accurate means of collateral flow measurement in a large population with variable degrees of coronary artery disease. METHODS: 200 patients (mean (SD) age 64 (9) years; 100 diabetic and 100 non-diabetic) were enrolled in the study. Coronary collateral flow was assessed in 174 stenotic and in 26 angiographically normal vessels with a pressure guidewire (n = 131), Doppler guidewire (n = 36), or both (n = 33) to calculate pressure or flow velocity derived collateral flow index (CFI). Diabetic patients were perfectly matched with a non-diabetic control group for clinical, haemodynamic, and angiographic parameters. RESULTS: CFI did not differ between the diabetic and the non-diabetic patients (0.21 (0.12) v 0.19 (0.13), not significant). Likewise, CFI did not differ when only angiographically normal vessels (0.20 (0.09) v 0.15 (0.08), not significant) or chronic total coronary occlusions (0.30 (0.14) v 0.30 (0.17), not significant) were compared. Fewer patients in the diabetic group tended to have angina pectoris during the one minute vessel occlusion (60 diabetic v 69 non-diabetic patients, p = 0.15). CONCLUSION: Quantitatively measured coronary CFI did not differ between diabetic and non-diabetic patients with stable coronary artery disease.

Blood Flow Velocity↗
PubMed2004

Percutaneous closure of patent foramen ovale reduces the frequency of migraine attacks.

Among 215 patients referred for percutaneous closure of patent foramen ovale (PFO) after presumed paradoxical embolism, we assessed the prevalence of migraine. In the year prior to PFO closure, 48 (22%) patients had migraine, twice the expected prevalence of 10 to 12% in the general European population. In patients with migraine with aura, percutaneous PFO closure reduced the frequency of migraine attacks by 54% (1.2 +/- 0.8 vs 0.6 +/- 0.8 per month; p = 0.001) and in patients with migraine without aura by 62% (1.2 +/- 0.7 vs 0.4 +/- 0.4 per month; p = 0.006). PFO closure did not have an effect on headache frequency in patients with nonmigraine headaches (1.4 +/- 0.9 vs 1.0 +/- 0.9 per month; p = NS).

Adult↗
PubMed2004

Percutaneous closure of patent foramen ovale: impact of device design on safety and efficacy.

OBJECTIVE: To compare the safety and efficacy of percutaneous closure of patent foramen ovale (PFO) with the Amplatzer PFO occluder (Amplatzer) or the PFO STAR device (STAR) in patients with presumed paradoxical embolism. METHODS: Implantation characteristics, procedural complications, residual shunt, and recurrence of thromboembolic events were recorded prospectively in 100 consecutive patients undergoing percutaneous PFO closure with the STAR (n = 50) or Amplatzer (n = 50) devices between 1998 and 2001. The study was not randomised. Device implantation was successful in all cases. RESULTS: There were more procedural complications in the STAR than in the Amplatzer group (8/50 v 1/50, p = 0.01). More than one device placement attempt was an independent predictor of procedural complications (odds ratio (OR) 8.5, 95% confidence interval (CI) 1.3 to 55.8; p = 0.03). A residual shunt six months after PFO closure, assessed by transoesophageal contrast echocardiography, occurred more often in the STAR than the Amplatzer group (17/50 v 3/50, p = 0.004), and was predicted in the STAR group by the use of a device with a 5 mm as opposed to a 3 mm disc connector (OR 6.1, 95% CI 1.1 to 34.0; p = 0.04). The actuarial risk of recurrent thromboembolic events after 3.5 years was 16.8% (95% CI 7.6% to 34.6%) in the STAR and 2.7% (95% CI 0.4% to 17.7%) in the Amplatzer group after three years (p = 0.08). CONCLUSIONS: Percutaneous PFO closure with the Amplatzer PFO occluder had fewer procedural complications and was more likely to be complete than with the STAR device. These findings underline the importance of device design for successful percutaneous PFO closure.

Balloon Occlusion↗
PubMed2003

Clinical and angiographic outcome of patients with mild coronary lesions treated with balloon angioplasty or coronary stenting. Implications for mechanical plaque sealing.

AIMS: To investigate the clinical and angiographic outcome of patients with mild coronary lesions treated with balloon angioplasty or coronary stenting (coronary plaque sealing, i.e. dilatation of angiographically non-significant lesions) compared to moderate and severe stenoses. METHODS AND RESULTS: Patients with chronic stable angina and a single de novo lesion in a native coronary vessel scheduled to undergo percutaneous coronary intervention (PCI) were selected from 14 different studies. Off-line analysis of angiographic outcomes was assessed in all patients using identical and standardised methods of data acquisition, analysis and definitions. Clinical endpoints were adjudicated by independent clinical events committees. All quantitative coronary angiographic (QCA) analyses were performed in the same core laboratory. Stenosis severity prior to PCI was categorised into three groups: <50% diameter stenosis (DS), 50-99%DS and >99%DS pre. A total of 3812 patients were included in this study; 1484 patients (39%) were successfully treated with balloon angioplasty (BA) only and stented angioplasty was performed in 2328 patients (61%).One-year mortality and rate of non-fatal myocardial infarction (MI) (Kaplan-Meier) did not differ between BA and stented angioplasty for any of the stenosis severity categories. Following BA, the combined event rate (death and non-fatal MI) was 4.8, 4.6 and 0% in the <50, 50-99 and >99%DS categories, respectively. Following stented angioplasty, the combined event rate was 3.1, 4.4 and 4.8% in the same categories. The need for repeat revascularisation corrected for stenosis severity in the Cox proportional-hazards regression model was reduced by 20% after stented angioplasty (hazard ratio (HR) 0.80, 95%CI 0.69-0.93). CONCLUSION: The concept of plaque sealing is appealing from the theoretical point of view. However, with current technology, plaque sealing cannot prevent death and future non-fatal MIs in the long-term because 1-year event rates after PCI of non-significant stenoses remain unacceptably elevated when compared with the estimated 1-year probability of a non-fatal MI in lesions with a <50%DS. Moreover, major adverse cardiac events at 1-year after PCI are not directly related to the degree of pre-procedural stenosis severity.

Angina Pectoris↗
PubMed2003

Novel management strategy for patients with suspected pulmonary embolism.

AIMS: A simple management strategy is required for patients with acute pulmonary embolism which allows a rapid and reliable diagnosis in order to start timely and appropriate treatment. METHODS AND RESULTS: Two hundred and four consecutive patients with suspected pulmonary embolism were managed according to a standardized protocol based on the clinical pretest probability and the initial haemodynamic presentation (shock index=heart rate divided by systolic blood pressure). Patients with a high pretest probability and a positive shock index (> or =1) (n=21) underwent urgent transthoracic echocardiography. Based on the presence or absence of right ventricular dysfunction, reperfusion treatment was initiated immediately. Patients with a negative shock index (<1) (n=183) underwent diagnostic evaluation including pretest probability, D-dimer, and spiral computed tomography (CT) as first-line tests. Echocardiography was performed only when a central pulmonary embolism was found in the spiral CT(n=33). According to our strategy, 98 patients met the diagnostic criteria of pulmonary embolism: 75 patients (all shock index <1) were treated with heparin alone, 16 (seven had a shock index > or =1) with thrombolysis, four (all shock index > or =1) with catheter fragmentation, and three (all shock index > or =1) with surgical embolectomy. The all-cause mortality rate at 30 days was 5%, and at 6 months 11%. Right ventricular dysfunction on baseline echocardiography was not associated with a higher mortality rate at 6 months (logrank 2.4, P=0.12). CONCLUSIONS: The novel management strategy for patients with suspected pulmonary embolism resulted in a rapid diagnosis and treatment with a low 30-day mortality. In patients with pulmonary embolism and a positive shock index, time-consuming imaging tests can be avoided to reduce the risk of sudden death and not to delay reperfusion therapy.

Acute Disease↗
PubMed2003

[Cryptogenic stroke and patent foramen ovale].

A stroke of unknown etiology is commonly referred to as cryptogenic and is diagnosed in a considerable patient population of especially young age. Numerous case-control studies revealed a strong and consistent association between cryptogenic stroke and the presence of a patent foramen ovale. This relationship corroborates paradoxical embolism as likely stroke mechanism in this patient population. In approximately twenty-five percent of patients with cryptogenic stroke, the patent foramen ovale is accompanied by an atrial septal aneurysm, which considerably heightens the risk for recurrent neurological events. Therapeutic measures for secondary prevention in this patient population encompass medical treatment with antiplatelet agents or anticoagulants and surgical or percutaneous closure of patent foramen ovale. Currently, randomised clinical studies compare medical treatment with closure of patent foramen ovale to determine the most effective treatment strategy in this patient population.

Administration, Oral↗
PubMed2003

Sexual activity in hypertensive men.

Erectile dysfunction is one of the major obstacles for noncompliance in the antihypertensive treatment. It has been shown that various antihypertensive drugs have a negative influence on sexual activity such as diuretics and beta-blockers. Thus, the purpose of the present study was to evaluate the effect of valsartan, an AT1-receptor antagonist, or its combination with hydrochlorothiazide on sexual activity in hypertensive patients. A total of 2202 patients (mean age 54+/-8 years) with hypertension systolic blood pressure (SBP)> or =140 mmHg, diastolic blood pressure (DBP)> or =95 mmHg), or with pretreated hypertension, were included in the present analysis. Blood pressure was measured at baseline, after 8 and 16 weeks, respectively. Sexual activity was assessed with a questionnaire at each of the three visits. Sexual activity (intercourse per week) was determined in three groups: controls (n=27; conventional therapy); valsartan group (n=1899); valsartan in combination with hydrochlorothiazide (n=276). There were 26 drop outs. SBP (-18.6 mmHg) and DBP (-11.6 mmHg) decreased significantly in all three groups. Sexual activity decreased slightly in controls from 1.3 to 0.9 times per week (NS), whereas it increased in the valsartan group from 1.0 to 1.6 times during follow-up (P<0.0001). Similarly, sexual activity increased in the combination group from 0.9 to 1.3 times per week during follow-up (P<0.0001). No sexual activity was reported by 467 (21%) of the 2202 patients at baseline and 154 (7%) at 16 weeks follow-up (P<0.05). Impaired sexual activity is common in hypertensive patients (app. 20%). Valsartan increases the rate of sexual intercourses per week, whereas conventional therapy affects sexual activity adversely.

Adult↗