PubMed Health⌕ Search

Biomedical subjects

Thomas Weber

Publications and source records attributed to Thomas Weber.

At least 19 recordsLinked to original sources
PubMed2003

Arterial stiffness, wave reflections, and the risk of coronary artery disease.

BACKGROUND: Increased arterial stiffness, determined invasively, has been shown to predict a higher risk of coronary atherosclerosis. However, invasive techniques are of limited value for screening and risk stratification in larger patient groups. METHODS AND RESULTS: We prospectively enrolled 465 consecutive, symptomatic men undergoing coronary angiography for the assessment of suspected coronary artery disease. Arterial stiffness and wave reflections were quantified noninvasively using applanation tonometry of the radial artery with a validated transfer function to generate the corresponding ascending aortic pressure waveform. Augmented pressure (AP) was defined as the difference between the second and the first systolic peak, and augmentation index (AIx) was AP expressed as a percentage of the pulse pressure. In univariate analysis, a higher AIx was associated with an increased risk for coronary artery disease (OR, 4.06 for the difference between the first and the fourth quartile [1.72 to 9.57; P<0.01]). In multivariate analysis, after controlling for age, height, presence of hypertension, HDL cholesterol, and medications, the association with coronary artery disease risk remained significant (OR, 6.91; P<0.05). The results were exclusively driven by an increase in risk with premature vessel stiffening in the younger patient group (up to 60 years of age), with an unadjusted OR between AIx quartiles I and IV of 8.25 (P<0.01) and a multiple-adjusted OR between these quartiles of 16.81 (P<0.05). CONCLUSIONS: AIx and AP, noninvasively determined manifestations of arterial stiffening and increased wave reflections, are strong, independent risk markers for premature coronary artery disease.

Aorta↗
PubMed2003

Hyperthyroidism.

Explore the source record for details and available documents.

Age Factors↗
PubMed2003

Expression of prestin-homologous solute carrier (SLC26) in auditory organs of nonmammalian vertebrates and insects.

Prestin, the fifth member of the anion transporter family SLC26, is the outer hair cell molecular motor thought to be responsible for active mechanical amplification in the mammalian cochlea. Active amplification is present in a variety of other auditory systems, yet the prevailing view is that prestin is a motor molecule unique to mammalian ears. Here we identify prestin-related SLC26 proteins that are expressed in the auditory organs of nonmammalian vertebrates and insects. Sequence comparisons revealed the presence of SLC26 proteins in fish (Danio, GenBank accession no. AY278118, and Anguilla, GenBank accession no. BAC16761), mosquitoes (Anopheles, GenBank accession nos. EAA07232 and EAA07052), and flies (Drosophila, GenBank accession no. AAF49285). The fly and zebrafish homologues were cloned and, by using in situ hybridization, shown to be expressed in the auditory organs. In mosquitoes, in turn, the expression of prestin homologues was demonstrated for the auditory organ by using highly specific riboprobes against rat prestin. We conclude that prestin-related SLC26 proteins are widespread, possibly ancestral, constituents of auditory organs and are likely to serve salient roles in mammals and across taxa.

Algorithms↗
PubMed2003

[Platelet glycoprotein IIb/IIIa inhibitors in coronary artery disease].

BACKGROUND: Inhibition of platelet activity at the injured coronary plaque is a target for novel therapeutic strategies. One of these mechanisms is the blockade of the platelet surface membrane glycoprotein (GP) IIb/IIIa receptor, which binds circulating fibrinogen or von Willebrand factor and crosslinks platelets as the final common pathway to platelet aggregation. Intravenous agents directed against this receptor include the chimeric monoclonal antibody fragment abciximab, the peptide inhibitor eptifibatide and nonpeptide mimetics tirofiban and lamifiban. RESULTS: During percutaneous coronary intervention, an absolute reduction of 1.5-6.5% in the 30-day risk of death, myocardial infarction or repeat urgent revascularization has been observed, with some variability in treatment effect among the agents tested. Treatment effect is achieved early with every modality of revascularization and maintained over the long-term up to 3 years. Increased bleeding risk may be minimized by reduction and weight adjustment of concomitant heparin dosing. In the acute coronary syndromes without ST segment elevation, absolute 1.5-3.2% reductions in 30-day rates of death or myocardial infarction have been achieved with 2- to 4-day courses of eptifibatide or tirofiban. Clinical benefit accrues during the period of drug infusion and is durable. Treatment effect may be enhanced among patients undergoing early coronary revascularization, with evidence of stabilization before intervention and suppression of postprocedural ischemic events. CONCLUSION: Thus, blockade of the platelet GP IIb/IIIa receptor reduces ischemic complications when used as an adjunct to percutaneous coronary intervention or the management of acute ischemic syndromes.

Abciximab↗
PubMed2003

Pericardial cysts in children: surgical or conservative approach?

The authors present a case of an 11-year-old boy with a history of mild asthma and cough who underwent radiographic examination of the chest. The radiograph showed a round, discrete mass in the right cardiophrenic angle. The patient underwent thoracoscopic excision, and histologic examination found a unilocular, pericardial cyst. The possible causes of mediastinal masses and an argument for their surgical removal is presented.

Child↗
PubMed2003

Systemic embolism from a large descending aortic thrombus.

With the advent of transesophageal echocardiography (TEE), thrombi of the aorta are becoming increasingly recognized as possible sources of systemic emboli. This report describes a 58-year-old woman with multiple unexplained peripheral emboli. A giant thrombus of the descending aorta has been identified as the source of systemic thromboembolism. The patient refused surgery and was treated successfully with long-term anticoagulation.

Anticoagulants↗
PubMed2003

In vivo recording of monophasic action potentials in awake dogs.

Assessment of cardiac repolarization in dogs in vivo is of interest in numerous experimental canine models. Previous studies have used monophasic action potentials (MAPs) to investigate repolarization in vitro and in vivo in anesthetized animal models. Therefore, an approach for recording MAPs in awake dogs without the interference of anesthesia is desirable. We describe an experimental technique to record MAPs in conscious dogs by means of conventional rubber introducers which are implanted into the internal jugular vein. Atrial as well as ventricular MAPs can be simultaneously measured without complications. Pacing thresholds are low and stable over time. Continuous MAP recordings of stable amplitude can be achieved from the same endocardial site for periods up to 1h. Antegrade and retrograde atrioventricular nodal conduction properties can be assessed. Programmed stimulation can be performed to simultaneously determine local refractory periods and MAP duration at cycle lengths from 500 to 200ms. In awake, unsedated dogs measuring MAPs via rubber introducers permits safe, long-term recording of MAPs. Such recordings may be useful for safety pharmacologic studies in evaluating cardiovascular and noncardiovascular drugs with respect to their effects on repolarization. In various canine in vivo models including in vivo models of long QT syndrome, heart failures or sudden cardiac death, the present technique permits electrophysiologic measurements without the interference of anesthesia.

Action Potentials↗
PubMed2003

Clinical and angiographic outcome after cutting balloon angioplasty.

The cutting balloon is a new device for coronary angioplasty, that, by the combination of incision and dilatation of the plaque, is believed to be promising for treatment of in-stent restenosis. The purpose of the study was to evaluate the safety and efficacy of CBA. We reviewed the immediate and 6-month follow-up angiographic and clinical outcome of 147 patients (109 men and 38 women) with a mean age of 67.3 +/- 10 undergoing this procedure at eight interventional centers in Austria. The target lesions treated with CBA were in-stent restenosis in 61% of patients, stenosis after balloon angioplasty in 8% of patients, and native lesions in 33% of patients. Sixty-five percent of the patients included had multivessel disease. Lesion type was A in 18% of patients, B1 in 31% of patients, B2 in 39% of patients, and C in 12% of patients. The degree of stenosis was 87% +/- 9%, the length of the target lesion treated with CBA was 8.8 +/- 5.1 mm. Target vessel was left circumflex artery in 22 cases, right coronary artery in 36 cases, and left anterior descending artery in 89 cases. The overall procedural success rate was 90.5%. "Stand-alone" CBA was performed in 63% of patients, the procedure was combined with coronary stenting in 16% of patients, and with balloon angioplasty in 21% of patients. Coronary complications occurred in eight cases (5.4%) with coronary dissection in seven (total dissection rate of 4.7%) and urgent bypass surgery in one case (0.7%). No further complications such as death, occlusion, or perforation of coronary arteries, embolization, or thrombosis were observed. Six-month clinical follow-up revealed q-wave myocardial infarction in 2.7% of patients, aortocoronary bypass surgery in 8.5% of patients, and repeated percutaneous coronary intervention in 17% of patients (11.5% with stenting). Six-month angiographic follow-up of patients with recurrent angina showed target lesion restenosis (> 50% diameter stenosis) in 14% of patients, late lumen loss with < or = 50% diameter stenosis in 6% of patients and progression of "other than target" lesions with > 50% diameter stenosis in 14% of patients. This series demonstrates the safety and feasibility of cutting balloon angioplasty in patients with complex coronary artery disease and in-stent restenosis.

Adult↗
PubMed2003

Endogenous glycosides in critically ill patients.

OBJECTIVE: To determine the incidence of critically ill patients displaying endogenous digitalis-like-immunoreactive substances (DLIS) and to examine the relationship of these hormones to routine laboratory variables, the underlying disease, myocardial function, hemodynamic status, severity of illness, systemic inflammation, and mortality rate. DESIGN: Sera of 401 consecutive critically ill patients, not treated with cardiac glycosides, were analyzed for DLIS (digitoxin and digoxin, TDx; Abbott Diagnostics, North Chicago, IL) and endogenous ouabain. Normal values of endogenous ouabain were determined in 62 healthy volunteers. We measured pro- and anti-inflammatory mediators (L-selectin, tumor necrosis factor-alpha, interleukin-1beta, interleukin-2, interleukin-6, interleukin-10), C-reactive protein, and serum amyloid A protein as well as patients' Acute Physiology and Chronic Health Evaluation II and Goris scores. In a subgroup of patients with a pulmonary artery catheter (n = 95), we determined cardiac output, pulmonary artery occlusion pressure, systemic and pulmonary vascular resistance, left ventricular stroke volume, and right and left stroke work. SETTING: Two surgical intensive care units of an university hospital. SUBJECTS: Sera of 401 consecutive critically ill patients. INTERVENTIONS: Blood sampling. MEASUREMENTS AND MAIN RESULTS: Of the 401 patients tested, 343 had nonmeasurable DLIS concentrations (DLIS-negative), and 58 (14.5%) had positive digoxin (n = 18) or digitoxin (n = 34) concentrations (DLIS-positive) or were positive in both tests (n = 6). Mean endogenous ouabain concentrations were nine-fold increased in DLIS-positive (3.59 +/- 1.43 nmol/L) and three-fold increased in DLIS-negative (1.34 +/-.81 nmol/L) patients compared with controls (0.38 +/- 0.31 nmol/L). DLIS and ouabain concentrations closely correlated with the Acute Physiology and Chronic Health Evaluation II and Goris score and were associated with increased concentrations of transaminases, bilirubin, aldosterone, cortisol, serum creatinine, fractional sodium excretion, proinflammatory mediators, C-reactive protein, and serum amyloid A (p <or=.009). The hospital mortality rates of DLIS-positive and DLIS-negative patients were 12% and 3.2%, respectively, and for patients with ouabain concentrations above and below 2 nmol/L 38.6% and 0.6%, respectively. In DLIS-positive patients with pulmonary artery catheter (n = 23), cardiac output, stroke volume, and left ventricular stroke work were decreased, and pulmonary artery occlusion pressure and central venous pressure were increased (p <or=.009). CONCLUSIONS: Different types of endogenous glycosides including endogenous ouabain are elevated in a significant proportion of critically ill patients. The occurrence of these substances is associated with increased morbidity and hospital mortality rates, possibly due to systemic inflammatory processes. DLIS but not endogenous ouabain concentrations were found to be related to left ventricular function.

APACHE↗