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Biomedical subjects

T Budde

Publications and source records attributed to T Budde.

At least 19 recordsLinked to original sources
PubMed2006

Mediterranean diet has no effect on markers of inflammation and metabolic risk factors in patients with coronary artery disease.

OBJECTIVE: Mediterranean diet is associated with decreased levels of inflammatory markers and metabolic risk factors in epidemiologic studies and recent trials on patients with metabolic syndrome. Given the recent improvements in medical treatments, it is unclear if such beneficial effects are also present in patients with coronary artery disease (CAD). We therefore investigated the effect of Mediterranean diet on markers of inflammation and metabolic risk factors in patients with treated CAD. DESIGN: Randomized, controlled trial. SUBJECTS: A total of 101 patients (59.4+/-8.6 years, 23% female) with established and treated CAD (80% statins). INTERVENTIONS: Participants were assigned to a Mediterranean diet group (MG; n=48) with a 1-year program of 100 h of education, or to a written advice-only group (AG; n=53). Before and after intervention, we measured serum high-sensitivity C-reactive protein (hs-CRP), fibrinogen, fasting insulin, homocysteine, serum lipids and plasma fatty acids. RESULTS: The Mediterranean diet program increased the intakes of fish, fruits/vegetables and moderately of canola/olive oil and increased plasma concentrations of long-chain n-3 polyunsaturated fatty acids in the MG. Median hs-CRP and mean fibrinogen, homocysteine, fasting insulin, triglycerides and serum cholesterols remained unchanged in both groups. CONCLUSIONS: Adoption of a Mediterranean diet by patients with medically treated CAD has no effect on markers of inflammation and metabolic risk factors. SPONSORSHIP: Alfried Krupp Foundation, Essen, Germany.

Biomarkers↗
PubMed2003

[Prognostic value of noninvasive coronary plaque burden quantification in patients with risk factors].

Non-invasive quantitative indices of atherosclerosis are promising new parameters for an improved prognostic stratification of patients with risk factors that aim at individualized risk factor assessment and modification. In a recently published ACC/AHA consensus document, further data on the diagnostic and prognostic value of coronary calcified plaque quantification were strongly encouraged prior to its use in the general population. In this present work we summarize data published since, which contribute significantly to the prognostic value of fast CT-based noninvasive coronary calcified plaque quantification. It is a measure of atherosclerostic disease activity and is hence an index for the likelihood of future cardiovascular events. Current data indicate that noninvasive quantification of coronary atherosclerosis has incremental prognostic value beyond conventional single risk factor assessment. However, it is not clear yet whether it has a significant value beyond quantitative combined risk assessment using complex risk prediction models such as Framingham charts. Results from ongoing prospective trials such as the MESA study in the US and the Heinz Nixdorf Recall study in Germany will clarify some of the pending issues. In addition, it is still unclear, at what stage of the disease process, which of the available imaging tools will provide optimal diagnostic and prognostic value for the individual patient.

Adult↗
PubMed2003

[A "late" scimitar syndrome. Diagnostic contribution of cardiac computed tomography].

A 51-year-old female hospitalized with a non-specific colitis, presented a crescent-like shadow in the right lower lung accompanied by a reduced right lung volume on a routine chest x-ray. There was no family history of congenital heart disease. The initially performed, noninvasive, contrast enhanced cardiac CT (electron-beam tomography [EBT]) proved the suspected diagnosis of a partial, anomalous pulmonary, transdiaphragmatic vein drainage (APVD) in combination with a hypoplastic right lower lobe and dextrocardia. These findings are in accordance with scimitar syndrome. Regarding to the clinical situation with symptoms like slowly progressive dyspnea on exertion and low exercise tolerance for the last 2 years and an invasively documented left-to-right shunt ratio >50% (Qp:Qs = 2.6 : 1) surgical repair was recommended. The anomalous vein was connected to the left atrium creating a "neo-septum". On a postoperative checkup after 9 months the patient is without any medication, symptoms during moderate activity are relieved, exercise tolerance was substantially better and noninvasive imaging visualized the corrected drainage of the anomalous vein to the left atrium.

Anastomosis, Surgical↗
PubMed2001

Fluorescent detection of Zn(2+)-rich vesicles with Zinquin: mechanism of action in lipid environments.

High concentrations of free Zn2+ ions are found in certain glutamatergic synaptic vesicles in the mammalian brain. These terminals can be visualized histochemically with quinoline sulfonamide compounds that form fluorescent complexes with Zn2+. The present study was undertaken to examine the interaction of the water-soluble quinoline sulfonamide probe, Zinquin (2-methyl-8-(toluene-p-sulfonamido)-6-quinolyloxyacetic acid) with the complex heterogeneous cellular environment. Experiments on rat hippocampal and neocortical slices gave indications that Zinquin in its free acid form was able to diffuse across the plasma and synaptic vesicle membranes. Further experiments were undertaken on unilamellar liposomes to study the interaction of Zinquin and its metal complexes in membranes. These experiments confirmed that Zinquin is able to diffuse across lipid bilayers. Steady-state and time-resolved fluorimetric studies showed that Zinquin in aqueous solution mainly forms a 1:2 (metal:ligand) complex with small amounts of a 1:1 complex. Formation of the 1:1 complex was favored by the presence of lipid, suggesting that it partitions into membranes. Evidence is presented that Zinquin can act as a Zn(2+)-ionophore, exchanging Zn2+ for two protons. The presence of a pH gradient across vesicles traps the Zn(2+)-probe complex within the vesicles. Zinquin is useful as a qualitative probe for detecting the presence of vesicular Zn2+; however, its tendency to partition into membranes and to serve as an ionophore should be borne in mind.

Animals↗
PubMed2000

Ca2+-induced Ca2+ release supports the relay mode of activity in thalamocortical cells.

Ca2+ ions play an important role during rhythmic bursting of thalamocortical neurons within sleep. The function of Ca2+ during the tonic relay mode of these neurons during wakefulness is less clear. Here, we report that tonic activity in thalamocortical cells results in an increase in the intracellular Ca2+ concentration and subsequent release of Ca2+ from intracellular stores mediated via ryanodine receptors (RyRs). Blockade of Ca2+ release shifted the regular firing of single action potentials toward the generation of spike clusters. Regular spike firing and intracellular Ca2+ release thus appear to be functionally coupled in a positive feedback manner, thereby supporting the relay mode of thalamocortical cells during wakefulness. Regulatory influences may be coupled to this system via the cyclic ADP ribose pathway.

Action Potentials↗
PubMed1999

A prognostic computer model to individually predict post-procedural complications in interventional cardiology: the INTERVENT Project.

AIMS: The purpose of this part of the INTERVENT project was (1) to redefine and individually predict post-procedural complications associated with coronary interventions, including alternative/adjunctive techniques to PTCA and (2) to employ the prognostic INTERVENT computer model to clarify the structural relationship between (pre)-procedural risk factors and post-procedural outcome. METHODS AND RESULTS: In a multicentre study, 2500 data items of 455 consecutive patients (mean age: 61.1+/-8.3 years: 33-84 years) undergoing coronary interventions at three university centres were analysed. 80.4% of the patients were male, 16.7% had unstable angina, and 5.1%/10.1% acute/subacute myocardial infarction. There were multiple or multivessel stenoses in 16.0%, vessel bending >90 degrees in 14.5%, irregular vessel contours in 65.0%, moderate calcifications in 20.9%, moderate/severe vessel tortuosity in 53.2% and a diameter stenosis of 90%-99% in 44.4% of cases. The in-lab (out-of-lab) complications were: 0.4% (0.9%) death, 1.8% (0.2%) abrupt vessel closure with myocardial infarction and 5.5% (4.0) haemodynamic disorders. CONCLUSION: Computer algorithms derived from artificial intelligence were able to predict the individual risk of these post-procedural complications with an accuracy of >95% and to explain the structural relationship between risk factors and post-procedural complications. The most important prognostic factors were: heart failure (NYHA class), use of adjunctive/alternative techniques (rotablation, atherectomy, laser), acute coronary ischaemia, pre-existent cardiac medication, stenosis length, stenosis morphology (calcification), gender, age, amount of contrast agent and smoker status. Pre-medication with aspirin or other cardiac medication had a beneficial effect. Techniques, such as laser angioplasty or atherectomy were predictors for post-procedural complications. Single predictors alone were not able to describe the individual outcome completely.

Adult↗
PubMed1998

Distribution of L-type calcium channels in rat thalamic neurones.

One major pathway for calcium entry into neurones is through voltage-activated calcium channels. The distribution of calcium channels over the membrane surface is important for their contribution to neuronal function. Electrophysiological recordings from thalamic cells in situ and after acute isolation demonstrated the presence of high-voltage activated calcium currents. The use of specific L-type calcium channel agonists and antagonists of the dihydropyridine type revealed an about 40% contribution of L-type channels to the total high-voltage-activated calcium current. In order to localize L-type calcium channels in thalamic neurones, fluorescent dihydropyridines were used. They were combined with the fluorescent dye RH414, which allowed the use of a ratio technique and thereby the determination of channel density. The distribution of L-type channels was analysed in the three main thalamic cell types: thalamocortical relay cells, local interneurones and reticular thalamic neurones. While channel density was highest in the soma and decreased significantly in the dendritic region, channels appeared to be clustered differentially in the three types of cells. In thalamocortical cells, L-type channels were clustered in high density around the base of dendrites, while they were more evenly distributed on the soma of interneurones. Reticular thalamic neurones exhibited high density of L-type channels in more central somatic regions. The differential localization of L-type calcium channels found in this study implies their predominate involvement in the regulation of somatic and proximal dendritic calcium-dependent processes, which may be of importance for specific thalamic functions, such as those mediating the transition from rhythmic burst activity during sleep to single spike activity during wakefulness or regulating the relay of visual information.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1998

The voltage-dependent conductances of rat neocortical layer I neurons.

Whole cell patch-clamp techniques were used to study voltage-dependent sodium (Na+), calcium (Ca2+), and potassium (K+) conductances in acutely isolated neurons from cortical layer I of adult rats. Layer I cells were identified by means of gamma-aminobutyric acid (GABA) immunocytochemistry. Positive stainings for the Ca2+-binding protein calretinin in a subset of cells, indicated the presence of Cajal-Retzius (C-R) cells. All investigated cells displayed a rather homogeneous profile of voltage-dependent membrane currents. A fast Na+ current activated at about -45 mV, was half-maximal steady-state inactivated at -66.6 mV, and recovery from inactivation followed a two-exponential process (tau1 = 8.4 ms and tau2 = 858.8 ms). Na+ currents declined rapidly with two voltage-dependent time constants, reaching baseline current after some tens of milliseconds. In a subset of cells (< 50%) a constant current level of < 65 pA remained at the end of a 90 ms step. A transient outward current (Ifast) activated approximately -40 mV, declined rapidly with a voltage-insensitive time constant (tau approximately 350 ms) and was relatively insensitive to tetraethylammonium (TEA, 20 mM). Ifast was separated into two components based on their sensitivity to 4-aminopyridine (4-AP): one was blocked by low concentrations (40 microM) and a second by high concentrations (6 mM). After elimination of Ifast by a conditioning prepulse (50 ms to -50 mV), a slow K+ current (I(KV)) could be studied in isolation. I(KV) was only moderately affected by 4-AP (6 mM), while TEA (20 mM) blocked most (> 80%) of the current. I(KV) activated at about -40 mV, declined monoexponentially in a voltage-dependent manner (tau approximately 850 ms at -30 mV), and revealed an incomplete steady-state inactivation. In addition to Ifast and I(KV), indications of a Ca2+-dependent outward current component were found. When Na+ currents, Ifast, and I(KV) were blocked by tetrodotoxin (TTX, 1 microM), 4-AP (6 mM) and TEA (20 mM) an inward current carried by Ca2+ was found. Ca2+ currents activated at depolarized potentials at about -30 mV, were completely blocked by 50 microM cadmium (Cd2+), were sensitive to verapamil (approximately 40% block by 10 microM), and were not affected by nickel (50 microM). During current clamp recordings, isolated layer I neurons displayed fast spiking behaviour with short action potentials (approximately 2 ms, measured at half maximal amplitude) of relative small amplitude (approximately 83 mV, measured from the action potential threshold).

Animals↗
PubMed1997

Lack of regulation by intracellular Ca2+ of the hyperpolarization-activated cation current in rat thalamic neurones.

1. The regulation of the hyperpolarization-activated cation current, Ih, in thalamocortical neurones by intracellular calcium ions has been implemented in a number of mathematical models on the waxing and waning behaviour of synchronized rhythmic activity in thalamocortical circuits. In the present study, the Ca2+ dependence of Ih in thalamocortical neurones was experimentally investigated by combining Ca2+ imaging and patch-clamp techniques in the ventrobasal thalamic complex (VB) in vitro. 2. Properties of Ih were analysed before and during rhythmic stimulation of Ca2+ entry by trains of depolarizing voltage pulses. Despite a significant increase in intracellular Ca2+ concentration ([Ca2+]i) from resting levels of 74 +/- 23 nM to 251 +/- 78 nM upon rhythmic stimulation, significant differences in the voltage dependence of Ih activation did not occur (half-maximal activation at -86.4 +/- 1.3 mV vs. -85.2 +/- 2.9 mV; slope of the activation curve, 11.2 +/- 2.4 mV vs. 12.5 +/- 2.5 mV). Recording of Ih with predefined values of [Ca2+]i (13.2 nM or 10.01 microM in the patch pipette) revealed no significant differences in the activation curve or the fully activated I-V relationship of Ih. 3. In comparison, stimulation of the intracellular cyclic adenosine monophosphate (cAMP) pathway induced a significantly positive shift in Ih voltage dependence of +5.1 +/- 1.9 mV, with no alteration in the fully activated I-V relationship. 4. These data argue against a direct regulation of Ih by intracellular Ca2+, and particularly do not support a primary role of Ca(2+)-dependent modulation of the Ih channels in the waxing and waning of sleep spindle oscillations in thalamocortical neurones.

Animals↗
PubMed1997

Voltage-activated intracellular calcium transients in thalamic relay cells and interneurons.

The dynamics of intracellular calcium concentration ([Ca2+]i) following activation of low voltage-activated (LVA) and high voltage-activated (HVA) Ca2+ currents were studied in identified relay neurons and interneurons of the rat dorsal lateral geniculate nucleus (LGNd) in situ using Ca2+ imaging and patch-clamp techniques. In relay neurons, [Ca2+]i transients associated with the LVA Ca2+ current showed a fairly homogeneous somatodendritic distribution, whereas HVA transients significantly decreased to 65% of the somatic value at 60 microns dendritic distance. In interneurons, LVA transients significantly increased to 239% of the somatic value at 60 microns dendritic distance, whereas HVA transients were not significantly different in the soma and dendrites. These results indicate differences in [Ca2+]i dynamics, which may reflect a heterogeneous distribution of Ca2+ channels contributing to subcellular compartmentation in the two types of thalamic neurons.

Animals↗
PubMed1997

Imaging free zinc in synaptic terminals in live hippocampal slices.

Some glutamatergic synapses in the mammalian central nervous system exhibit high levels of free ionic zinc in their synaptic vesicles. The precise role of this vesicular zinc remains obscure, despite suggestive evidence for zinc as a neuromodulator. As a step towards elucidating the role of free zinc in the brain we have developed a method for imaging zinc release in live brain slices. A newly synthesized zinc-sensitive fluorescent probe, N-(6-methoxy-8-quinolyl)-p-carboxybenzoylsulphonamide (TFLZn), was used to monitor intracellular zinc in live rat hippocampal slices. The dye loaded into the zinc-rich synaptic vesicles of the mossy fibre terminals in the hippocampal formation. Direct electrical stimulation of the mossy fibre pathway diminished the fluorescence in the mossy fibre terminals, consistent with a stimulus-dependent zinc release. The synaptic release of zinc was followed by the rapid replenishment of the zinc levels in vesicles from an as yet unidentified intracellular zinc source. Furthermore, we present evidence that zinc may play a role in a form of long-term potentiation exhibited by the mossy fibre pathway.

Animals↗
PubMed1997

A prognostic computer model to predict individual outcome in interventional cardiology. The INTERVENT Project.

It is not yet possible to predict an individual's outcome from percutaneous transluminal coronary angioplasty or alternative/adjunctive coronary interventional techniques. The purpose of the INTERVENT project is to redefine complications associated with coronary interventions, to set up a prognostic computer model to predict individual outcome and to compare the results to those of conventional statistical techniques. 2500 data items were analysed in 455 consecutive patients (mean age: 61.1 +/- 8.3 years; range 33-84 years; 80.4% male, 16.7% unstable angina, 5.1%/10.1% acute/subacute myocardial infarction) undergoing coronary interventions at three university centres. In-lab/out-of-lab complication rates were 0.4%/0.9% (death), 1.8%/0.2% (abrupt vessel closure with myocardial infarction) and 5.5%/4.0% (haemodynamic complications). Computer algorithms derived by applying techniques from artificial intelligence were able (1) to reduce the set of possible relevant risk factors from 2500 to about 40, (2) to predict individual risk with an accuracy of > 95% and (3) to explain the structural relationship between outcome and risk factors. Patient data from two centres were used to construct and test the algorithm. Data from a third centre were used to evaluate the algorithm. The most important predictors-were acute myocardial infarction, heart failure (NYHA class > II), unstable angina, complex lesions, high low density lipoprotein cholesterol and duration of coronary heart disease. Neither age nor gender impaired the percutaneous transluminal coronary angioplasty results in acute ischaemic syndromes; however, for stable angina, procedural risk increased with age. There was little risk from primary percutaneous transluminal coronary angioplasty in acute myocardial infarction in patients with NYHA heart failure classes I-II; however, the risk was high for patients in NYHA classes > II, either with or without additional thrombolysis. Alternative/adjunctive intervention techniques were no predictors for in-lab-, but were predictors for post-procedural complications.

Adult↗
PubMed1996

[Acute epigastric pain after travel to the tropics. Emergency admission of a 28-year-old stewardess].

A 28-year-old stewardess was admitted to hospital with violent cramp-like pain in the right upper abdomen, which was accompanied by a single episode of watery pasty diarrhea. Over the next few days her symptoms persisted, she developed a high fever, and her general state of health deteriorated. Ultrasonography repeated on the fourth day then revealed a small space-consuming lesion in the right lobe of the liver. While the laboratory investigations initially remained negative, the suspected amebic abscess and colitis were subsequently also confirmed serologically.

Abdomen, Acute↗
PubMed1996

Biphasic defibrillation using a single capacitor with large capacitance: reduction of peak voltages and ICD device size.

The volume of current implantable cardioverter defibrillators (ICD) is not convenient for pectoral implantation. One way to reduce the size of the pulse generator is to find a more effective defibrillation pulse waveform generated from smaller volume capacitors. In a prospective randomized crossover study we compared the step-down defibrillation threshold (DFT) of a standard biphasic waveform (STD), delivered by two 250-microF capacitors connected in series with an 80% tilt, to an experimental biphasic waveform delivered by a single 450-microF capacitor with a 60% tilt. The experimental waveform delivered the same energy with a lower peak voltage and a longer duration (LVLD). Intraoperatively, in 25 patients receiving endocardial (n = 12) or endocardial-subcutaneous array (n = 13) defibrillation leads, the DFT was determined for both waveforms. Energy requirements did not differ at DFT for the STD and LVLD waveforms with the low impedance (32 +/- 4 omega) endocardial-subcutaneous array defibrillation lead system (6.4 +/- 4.4 J and 5.9 +/- 4.2 J, respectively) or increased slightly (P = 0.06) with the higher impedance (42 +/- 4 omega) endocardial lead system (10.4 +/- 4.6 J and 12.7 +/- 5.7 J, respectively). However, the voltage needed at DFT was one-third lower with the LVLD waveform than with the STD waveform for both lead systems (256 +/- 85 V vs 154 +/- 51 V and 348 +/- 76 V vs 232 +/- 54 V, respectively). Thus, a single capacitor with a large capacitance can generate a defibrillation pulse with a substantial lower peak voltage requirement without significantly increasing the energy requirements. The volume reduction in using a single capacitor can decrease ICD device size.

Adult↗
PubMed1995

Intracoronary stenting after unsuccessful PTCA. Early restenosis and explanation of stents during bypass surgery.

The case of a 63-year-old man is described, who received two intracoronary Palmaz-Schatz-Stents after dissection and occlusion following PTCA of two segments of the left anterior descending branch of the left coronary artery. Because of recurrent angina caused by early restenosis in the 'unprotected' segment between the stents, surgical revascularisation was performed and the stents were removed.

Angina Pectoris↗