PubMed Health⌕ Search

Biomedical subjects

U Busch

Publications and source records attributed to U Busch.

At least 73 records · Page 4Linked to original sources
PubMed1989

The efficacy of nifedipine and acebutolol in coronary artery disease assessed by radionuclide ventriculography.

The efficacy of a fixed combination of 10 mg nifedipine and 100 mg acebutolol was tested in 21 patients with angiographically proven coronary artery disease (CAD). Ejection fraction (EF), emptying and filling rate (VS and VD), and end-systolic volume (ESV) were assessed by means of radionuclide ventriculography at rest and during exercise prior to as well as 1 hour and 5 hours following oral drug application. Whereas exercise-induced worsening of cardiac function had been documented in all the patients prior to medication, EF and ESV improved significantly after drug administration.

Acebutolol↗
PubMed1989

Increase of vertebral density by combination therapy with pulsatile 1-38hPTH and sequential addition of calcitonin nasal spray in osteoporotic patients.

Combination therapy with the biologically active (1-38) human parathyroid hormone peptide and calcitonin using pulsatile and sequential activation of the skeleton for 14 months in patients with low-turnover osteoporosis resulted in an increase in trabecular bone mass. These favorable responses were observed without any significant changes in cortical (forearm) bone mass content.

Administration, Intranasal↗
PubMed1988

[Peripheral pulmonary stenosis: initial manifestation of a malignant teratoma].

A case of acquired pulmonic stenosis is described. The only symptoms reported by the patient, a seemingly healthy woman, were minor chest discomfort and mild dyspnea upon exertion for the last six month. Cardiac catheterization revealed stenoses of both the right and left pulmonary arteries. Magnetic resonance imaging revealed a mediastinal tumor mass that almost totally compressed the right main pulmonary artery and also encroached upon the left pulmonary artery. Histologically the tumor was a malignant teratoma. The subsequent course of treatment was complicated by cardiac tamponade. With regression of the tumor during therapy the signs of pulmonic stenosis disappeared. In cases with acquired pulmonic stenosis an underlying mediastinal tumor has to be considered.

Adult↗
PubMed1988

Pharmacokinetics and biodisposition of recombinant human interferon-alpha 2C in rat and marmoset.

Pharmacokinetics and biodiposition of recombinant human interferon-alpha 2C (IFN-alpha 2C) were studied in rats and marmosets (Callitrix jacchus). After intravenous bolus dose, serum concentrations of IFN-alpha 2C antigen declined triexponentially. After administration of 15 MIU/kg IFN-alpha 2C the mean t1/2 alpha was 3 min (rat) and 10 min (marmoset), t1/2 beta was 0.4 h (rat) and 1.2 h (marmoset), the mean terminal half-life t1/2 gamma was 2.8-6.3 h (rat) and 10-14 h (marmoset). The short alpha-phase was dominant, consistent with the high total serum clearance of 5 ml/min/kg (rat) or 2 ml/min/kg (marmoset), respectively. The low volumes of distribution (in both species 0.4-0.8 l/kg) indicated a mainly extracellular distribution of this drug. Absolute bioavailability after intramuscular and subcutaneous dosing ranged from 40-80% and the time of maximum serum level from 0.7-2.7 h (both species). Dose linearity was observed up to 15 MIU/kg for all routes of administration. The results demonstrate similarity of IFN-alpha 2C pharmacokinetics in rat and marmoset. Biodisposition of IFN-alpha 2C in rat was determined both by whole body autoradiography and analysis of antigen concentrations in tissue homogenates. The distribution of IFN-alpha 2C antigen showed a high correlation with capillary permeability and blood content of the different tissues. Thus, high levels were found in serum, kidney, lung, spleen, heart and liver, whereas the concentrations in muscle and brain were extremely low. Taken together, the data indicate that IFN-alpha 2C is predominantly eliminated by glomerular filtration, followed by tubular reabsorption, and finally lysosomal degradation in the kidney.

Animals↗
PubMed1988

[Age-related heart function in patients with healthy hearts].

Left ventricular function was investigated at rest and during submaximal exercise in 191 healthy subjects, including 46 women, by means of radionuclide ventriculography (RNV). As global parameters of heart function, ejection fraction (EF) and maximal rates of volume change during systole (VS) and diastole (VD) as well as endsystolic volume (ESV) were determined. These parameters were calculated for four age groups with mean ages of 32, 45, 55, and 64 years, respectively. At rest, heart rate (HR), EF, VS, and ESV were not significantly different in all age groups, whereas VD decreased with increasing age from 3.3 +/- 0.6 s-1 to 2.6 +/- 0.6 s-1. During exercise, HR, EF, VS, and VD increased in all groups, but less in the elderly. The smaller increase of EF and VD could be accounted for by HR alone. VS was both HR- and age-dependent. The age dependence of VD (at rest) and VS (under exercise) may reflect a reduction of myocardial compliance with increasing age. Differences of EF and VS with respect to sex were not observed, whereas VD was slightly lower in males.

Adolescent↗
PubMed1987

[MR tomography in cardiology. II: Flow phenomena].

Flow phenomena modify the information of MR tomograms and can cause artefacts which degrade the image quality. When ECG triggering and suitable modes of excitation are used, flow effects can give diagnostically relevant information concerning global and regional cardiac function and blood flow in vessels. The signal intensity of blood excited by an SE-mode is usually low. The spin echo increases due to the TR-effect. However, the TE-effect reduces the signal of flowing blood with increasing flow velocity. Phase shifts caused by flow generate line-shaped artefacts in the reconstructed tomograms and decrease the signal intensity of all odd spin echoes. The second order phase errors are compensated by phase recombination occurring in all even echoes. Therefore, in double echo acquisition the second spin echo of flowing blood can be higher than the first echo, especially when the flow velocity is physiologically or pathologically reduced. In multi-slice acquisition, time-of-flight effects can be observed, by which a resonance signal induced in one particular slice is shifted to and recorded in another slice.

Blood Flow Velocity↗
PubMed1986

New balloon catheter for prolonged percutaneous transluminal coronary angioplasty and bypass flow in occluded vessels.

A new balloon catheter was developed for continuous perfusion of coronary arteries during angioplasty (CPC catheter). Steerable Grüntzig balloon catheters (3.7 mm) with two lumina were formed. The first lumen was used for balloon inflation. Side holes to the second lumen proximally and distally to the balloon were created for coronary perfusion even during inflation phase. At a perfusion pressure of 120 mmHg, a flow rate of 63 +/- 3 ml/min with 0.9% saline and 43 +/- 1 ml/min with plasma expander were measured. In experiments on five dogs, dilation time until appearance of signs of ischemia could be prolonged in three of five dogs from 30 to 40 s, 120 to 203 s, and 180 to 420 s comparing conventional and CPC balloon catheters. In 11 patients with proximal lesions, dilation time could be increased from 39.5 +/- 23.9 s to 81.1 +/- 36.3 s (p less than 0.01) until appearance of angina pectoris. ST segment changes were observed in 10/11 patients using conventional catheters. Using CPC catheters, no ST segment changes were observed in four patients; time until appearance of ST segment changes was delayed in the other seven patients. The CPC catheter seems to be an alternative catheter in proximal lesions of the left and right coronary artery, allowing the possibility of prolonged dilation and increased safety to the patient. In case of dissection or perforation, the CPC catheter can be used for perfusion of the distal part of the coronary vessel until emergency bypass surgery.

Adult↗
PubMed1986

[Selective continuous coronary perfusion via an angioplasty catheter following acute vascular occlusion].

Since surgical revascularisation after PTCA-induced acute coronary occlusion in the majority of cases is delayed by at least 2 hours, we assessed the possibility of selective, volume-controlled coronary perfusion via the still indwelling angioplasty catheter for such a prolonged period using an external pump. Because of the high pressures required to provide adequate flow through many of the currently used catheters, an AC independent, pressure and volume controlled pump was developed which does not cause substantial hemolysis even at pressures beyond 10 atm. During in vitro tests the pressure-flow-rate relations and the degree of hemolysis and blood count changes were determined for various catheters. The previous catheters with a fixed wire tip caused excessive hemolysis which rendered prolonged coronary perfusion prohibitive. But even with the more recent catheters the presence of side holes near the catheter tip may at times cause significant hemolysis. In 20 out of 22 dogs the anterior descending (n = 18) or circumflex (n = 2) coronary artery was selectively perfused for 2 hours following balloon occlusion. The perfusion rate was adjusted according to the occurrence of ischemic signs in the ECG and for a drop in the coronary venous oxygen saturation which was monitored with a fiberoptic catheter. The intraluminal pressure within the selectively perfused vessel was recorded continuously but not used for adjustment of the perfusion rate. In no case was there a critical pressure increase in the selectively perfused vessel. When perfusion of the occluded vessel was stopped after 2 hours, massive myocardial ischemia developed which was reversible with resumption of perfusion. Using an adequate pump and the more recent, steerable angioplasty catheters which should not have side holes near the tip, selective coronary perfusion can be performed for at least 2 hours and is capable of preventing myocardial ischemia.

Angioplasty, Balloon↗
PubMed1985

[Improved occlusion tolerance time by continuous coronary perfusion with a modified Grüntzig coronary angioplasty catheter].

We evaluated the modified Grüntzig coronary angioplasty catheter, which allows for continuous antegrade coronary perfusion during balloon occlusion without the use of an external pump. During in vitro tests the flow rates for effective pressure differences between aorta and distal coronary vessel in the range between 25 and 100 mm Hg were determined. During in vivo tests in 10 dogs the effect of balloon occlusion with continuous perfusion (OM) was compared with conventional occlusion without perfusion (OC). The occlusion tolerance time (OTZ) as determined by the appearance of unequivocal signs of ischemia in the ECG, was 486 +/- 77 s for OM versus 256 +/- 82 s for OC with a relative, individual increase of 191 +/- 54% (p less than 0.01, data are given +/- SEM). Observed ST-elevation was less with OM than with OC (0.22 +/- 0.05 versus 0.33 +/- 0.06, p less than 0.05). Occlusion related pressure difference between aorta and occluded coronary vessel was less with OM than with OC (31 +/- 8 mm Hg versus 40 +/- 10 mm Hg, p = 0.05). In selected cases such a prolongation of the intracoronary balloon occlusion time may represent a distinct advantage.

Angioplasty, Balloon↗
PubMed1985

[Dissimilar course in the right and left ventricular function in a patient with dilated cardiomyopathy].

The case of a patient with severe dilative cardiomyopathy and cardiomegaly demonstrates that M-mode echocardiography and planar chest radiographs are not always sufficient to follow up the disease correctly. Using other non-invasive imaging modalities, in this case radionuclide ventriculography and NMR tomography, which provide more precise information with regard to morphology and function of both the right and the left heart, allows a more reliable follow-up of the disease.

Adult↗
PubMed1985

[Physiologic effect of short AV intervals on LV filling time in VDD pacemakers--mitral valve closure in relation to atrial and ventricular contraction].

The effect of mitral valve closure on LV filling time and the onset of LV systole were assessed in 21 normals, 11 patients with left bundle branch block and in 19 patients with VDD pacemakers, which were programmed for the AV intervals 50, 150 and 250 ms, by means of echo-apexcardiography. Mitral valve closure was significantly delayed with increasing delay of intraventricular conduction: 52 +/- 11 ms in normals, 65 +/- 20 ms in LBBB patients and 127 +/- 14 ms in VDD patients. There was a similar distribution of the apexcardiographic upstroke and aortic valve opening in the 3 groups. With increasing AV intervals mitral valve closure was earlier: 127 +/- 14 ms at AV = 50 ms, 83 +/- 38 ms at AV = 150 ms and 20 +/- 75 ms at AV = 250 ms whereas the onset of LV systole and mitral valve opening remained unaltered. Thus filling time expressed in percent of cycle length was reduced from 50 +/- 6% at AV = 50 ms to 45 +/- 9% and to 38 +/- 10% at AV = 250 ms (p less than 0.001). The late onset of LV systole in VDD pacemaker patients therefore reduces LV filling time unless this is compensated by programming a short AV interval in order to maintain the physiological interval between atrial and ventricular contraction.

Adult↗
PubMed1984

[Embolectomy in patients with pulmonary embolism without symptoms of shock].

The therapeutic spectrum for the management of patients with pulmonary embolism includes either drug therapy with anticoagulants or with thrombolytic agents, or embolectomy. The indications for either form of therapy are not always clearly separable, but, in general, surgery is reserved for those patients with massive embolism and shock. Large, mobile thromboemboli located centrally, either within the right heart or in the main pulmonary artery, bear the risk of further, possibly fatal, embolisation that might actually be increased by thrombolytic therapy. Therefore, demonstration of such a thromboembolus seems to justify the decision for prompt surgical removal even in the absence of shock as exemplified in the two cases presented here.

Aged↗