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Biomedical subjects

G Hör

Publications and source records attributed to G Hör.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of the effects of total sleep deprivation on cerebral blood flow using single photon emission computerized tomography.

HMPAO-single photon emission computerized tomography (SPECT) is a useful technique in studying cerebral blood flow (CBF). This method is suitable to evaluate the differences of CBF with reference to total sleep deprivation (TSD) within 24 h because of the short half-life of the radiopharmaceutical compound. In the present study, CBF before and after TSD was analysed in patients suffering from major depression. The morning before and after TSD, Tc-HMPAO-SPECT was performed in 20 patients. Hamilton Rating Scale for Depression scores and subjective ratings were obtained daily. Eleven patients responded to TSD; 9 were nonresponders. The main finding was a significant left temporal and mainly right parietal increase of CBF, which was observed in the responders only. CBF values and the severity of depression correlated inversely.

Adult↗
PubMed1992

Effect of propranolol and disopyramide on left ventricular function at rest and during exercise in hypertrophic cardiomyopathy.

In 19 patients with hypertrophic cardiomyopathy (15 males, 4 females, mean age 49.2 +/- 10.8 years) left ventricular function was studied with radionuclide ventriculography at rest and during exercise in a crossover design without intervention and after disopyramide and propranolol treatment. 15 of the 19 patients had a resting or latent intraventricular gradient of more than 30 mm Hg. Left ventricular function at rest and during exercise was evaluated before medication, 90 min after oral administration of 200 mg disopyramide or 160 mg propranolol and after 3 weeks of oral therapy with disopyramide 200 mg 2 times a day or propranolol 80 mg 4 times a day. After long-term treatment with disopyramide, resting ejection fraction decreased from 72 +/- 12 to 69 +/- 14% (p less than 0.01) and peak ejection rate (PER) decreased from 3.46 +/- 135 to 3.24 +/- 65 end-diastolic volume (EDV).s-1 (p less than 0.01). Peak filling rate (PFR) at rest decreased from 3.01 +/- 0.8 to 2.77 +/- 0.63 EDV.s-1 (p less than 0.05). Time to peak filling rate (TPFR) at rest and during exercise after acute and chronic therapy did not change compared to control values. Acute and long-term administration of propranolol lead to a significant reduction in heart rate at rest and during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

[Detection of the Köbner phenomenon of the skeleton of patients with psoriasis].

Psoriasis is a humorally controlled systemic disease. The degree of "eruptive strength" of manifestation results from hereditary factors (disposition) and environmental factors (provocation). We were able to demonstrate that the well-known Köbner phenomenon of the skin also occurs on the skeleton of patients suffering from psoriasis. We analysed 83 patients in whom bone scans were carried out. Our results indicate that provocation factors such as bacterial foci and/or trauma correlate with a significantly higher number of pathological scintigraphic findings, ranging up to "hot spots". Furthermore, not only did bone fractures remained scintigraphically positive for an unusually long time, traumas of the end phalanx could be demonstrated in 70% of psoriatic patients compared with 21% of a control group. Obviously, one factor alone or a combination of factors triggers the involvement of the skeleton as a "deep Köbner phenomenon". In psoriatic patients the response of bone metabolism to disturbance differs from that of non-psoriatic patients in that there is a long-lasting dysregulation. This explains the high correlation between skin and skeletal manifestation in psoriatics. Therefore the manifestation of psoriatic disease is due not to a single-stranded linear causal interrelation but to a multicausal "network pathogenesis". Bone scintigraphy is the diagnostic method of choice in patients with psoriatic osteoarthropathy and allows an objective evaluation of therapeutic success.

Adult↗
PubMed1992

[Myocardial function before and after reopening of chronic coronary occlusion].

To assess the myocardial function before and after reopening of chronic coronary artery occlusions, 20 patients were investigated at rest and during exercise with ECG and equilibrium radionuclide ventriculography. The recanalisation of the chronically occluded vessel was carried out by means of Rotacs-catheter in 17 patients, of a guide wire enforced by recanalisation-catheter in 2 patients and of a thin guide wire alone in 1 patient, always followed by conventional balloon angioplasty. After successful PTCA the average coronary artery stenosis diameter decreased from 100% to 34 +/- 6%. Angina pectoris and/or dyspnea observed during exercise were improved in 83% of the patients. The radionuclide global left ventricular ejection fraction at rest increased from 55 +/- 9% to 59 +/- 10% (p < 0.05), and during exercise from 52 +/- 12% to 61 +/- 12% (p < 0.05). The improvement in global ejection fraction at rest was more pronounced in 5 patients, who suffered from angina pectoris at rest before PTCA (from 56 +/- 4% to 65 +/- 9%, p < 0.05). It is concluded that reopening of chronically occluded coronary arteries in properly selected patients leads to a significant improvement of the global left ventricular function at rest and during exercise.

Adult↗
PubMed1991

Impairment of left ventricular function during coronary angioplastic occlusion evaluated with a nonimaging scintillation probe.

Impairment of left ventricular function during controlled myocardial ischemia induced by coronary angioplasty has been reported from angiographic and echocardiographic studies. Ejection fraction, peak ejection, peak filling rates, and end-systolic and end-diastolic volumes were investigated before, during and after coronary occlusion on-line with a nonimaging scintillation probe. The study consisted of 18 patients (mean age 59 +/- 10 years) with coronary artery stenosis of greater than 70%. During balloon inflation of 60 seconds' duration, coronary occlusion pressure was 31.6 +/- 12 mm Hg. There was no significant change in heart rate. Delay between first and second dilatation was 109 +/- 63 seconds. Ejection fraction decreased from 53 +/- 16 to 40 +/- 12% (first dilatation, p less than 0.01) and to 39 +/- 14% (second dilatation, p less than 0.01) and recovered to 51 +/- 16% 5 minutes after the second dilatation. Peak ejection rate was significantly reduced during the first and second balloon inflations. Peak filling rate decreased from 2.5 +/- 0.8 to 2.0 +/- 0.7 end-diastolic volume.s-1 (first dilatation, p less than 0.01) and to 1.8 +/- 0.7 end-diastolic volume.s-1 (second dilatation, p less than 0.01) and remained reduced at 2.2 +/- 0.7 end-diastolic volume.s-1 (p = not significant) at 5 minutes after the second dilatation. End-systolic and end-diastolic volumes increased significantly during the first and second dilatations and returned to normal after dilatation. It is concluded that short, controlled myocardial ischemia during coronary angioplasty leads to a decrease in systolic and diastolic left ventricular function. Sequential dilatations do not further decrease function if a sufficient interval is kept.

Angioplasty, Balloon, Coronary↗
PubMed1991

[Aortic valve insufficiency. Diagnosis, course, therapy].

A radionuclide ventriculographic procedure for the accurate quantification of aortic insufficiency has been developed, and its use in follow-up, pharmacotherapy and surgical planning tested. In 28 patients, follow-up over a period of 20 months revealed only slow progression of the chronic aortic insufficiency; worsening of the symptoms leading to the need for valve replacement was associated with a rapid deterioration of objective parameters. In patients with a stable condition, captopril administered for 4-8 weeks failed to reduce left ventricular overload to any significant extent, while reduction in volume overload was observed in patients with accompanying congestive heart failure or systemic hypertension. Clinical analysis revealed that, as a rule, the indication for valve replacement must be based on follow-up examination. If radionuclide ventriculography reveals a disproportionate enlargement of the ventricle, surgery is indicated even in the absence of symptoms.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1991

[Effect of bypass operation and balloon angioplasty on heart function at rest].

Improvement of exercise left-ventricular ejection fraction after successful aortocoronary bypass operation and transluminal coronary angioplasty has been demonstrated. The purpose of this study was to investigate in which patients improvement of left-ventricular function at rest can be observed. Radionuclide ventriculography and exercise stress test was carried out in 34 patients before and after successful aortocoronary bypass operation (Group 1), and in 69 patients before and after successful transluminal coronary angioplasty (Group 2). After bypass surgery, mean ejection fraction at rest increased from 42 +/- 11 to 49 +/- 13% (p less than 0.001). Marked improvement (greater than or equal to 5%) was observed in 19 patients (56%) in whom severe myocardial ischemia could be documented during exercise ECG (Group 1.1: Increase of ejection fraction from 40 +/- 14 to 54 +/- 12%, p less than 0.001; ischemia score during exercise test 8.8 +/- 10). In the remaining 15 patients no significant improvement occurred (Group 1.2: 43 +/- 16 vs. 43 +/- 16%, p = n.s.; ischemia score during exercise test 3.2 +/- 2.4, p = 0.02 vs. Group 1.1). After angioplasty, resting left-ventricular ejection fraction increased, on average, from 50 +/- 11 to 52 +/- 12% (p less than 0.001). Comparable to the results observed in patients after surgery, improvement was most pronounced in patients with severe exercise-induced ST-depression (Group 2.1: Increase of ejection fraction from 49 +/- 10 to 58 +/- 10%, p less than 0.001; ischemia score during exercise 2.5 +/- 2.3).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Experiences with the application of monoclonal Indium-111 antimyosin scintigraphy in the diagnosis of rejection episodes following orthotopic heart transplantation].

Indium-111-labeled Fab fragment imaging using a murine antimyosin monoclonal antibody (Myoscint, Centocor, Leiden) was evaluated for efficacy in detecting cardiac allograft rejection. Diagnosis of rejection was made by endomyocardial biopsy with four to five samples taken for each procedure. Eighty-one studies were performed in 25 patients (21 men, four women, mean age 50 +/- 9 years) from 2 weeks to 45 months after cardiac transplantation. 0.5 mg of the monoclonal antibody labeled with 60 MBq Indium-111 (Antimyosin-Fab-DTPA) was administered i.v. Planar scintigraphic images were obtained in LAO 45 and anterior projections as well as "half-body-scintigrams" 48 h after injection. Using the regions-of-interest-(ROI)technique the relative uptake over the lung and the heart was determined and an index of In-111 uptake was calculated. A heart-to-lung ratio of 1.5 or higher was considered indicative for moderate to severe rejection. Specificity was 86% (nine false-positive In-111 studies in 68 negative biopsy studies), sensitivity was 85% (two false-negative In-111 studies in 13 pathological biopsy studies). It is concluded that the In-111 method has a high sensitivity and specificity in detecting heart transplant rejection and may be useful in the monitoring of patients in the chronic phase after heart transplantation. The 48-h delay in establishing the diagnosis limits the applicability in acute severe rejection.

Adult↗
PubMed1991

[The significance of hot spots in psoriatic skeletal involvement].

Bone scintigraphy is a modern method of low specificity but very high sensitivity in determining early changes in bone metabolism. There is a relationship between excessive skeletal metabolic disorders of the bone and the appearance of foci of maximum radionuclide uptake, or "hot spots". This distribution of radionuclide uptake has a specific character. In a retrospective study, we investigated the distribution of hot spots in 92 patients with various forms of psoriatic disease. Hot spots were found at and near to joints only. In enthesopathies hot spots are not found, because of lack of substance. They do, however, show signs suggesting a major disorder in collagen metabolism. Hot spots indicate a rather acute degree of skeletal involvement in psoriatic disease and are also frequently found in very active phases of psoriatic disease. Therapy-induced regression is possible. Spontaneous regression was observed only in the case of hot spots of short duration. The correlation of scintigraphic findings with X-rays shows that hot spots are signs of maximal focal metabolic activity. In a high percentage of cases they are leading up to a state of destruction, which can be shown on X-rays later. Among other parameters, they indicate the likelihood of skeletal involvement in psoriatic disease. Moreover, they indicate a high risk of "psoriatic arthritis".

Adult↗
PubMed1991

Effect of aortic sclerosis on bone mineral measurements by dual-photon absorptiometry.

Measurements of the bone mineral content (BMC) of lumbar spine by dual-photon absorptiometry (DPA) are performed mainly in the anteroposterior (AP) projection. Due to superimposition of the abdominal aorta, the BMC measured for patients with aortic calcification usually is too high. To determine the influence of aortic calcifications, DPA scans were performed in the AP-projection on 100 dissected abdominal aortae with different degrees of atherosclerosis placed on a human lumbar spine cast in lucite. The measured values were compared with those obtained in the same projection without the aortae. The average increase of the BMC values relative to the mean for the vertebrae L2 to L4 for aortae with severe complicated lesions, i.e., those containing larger amounts of calcium, was 0.03 g/cm2, with a maximum deviation of 0.09 g/cm2. Aortae with fatty streaks or fibrous plaques did not cause significant increases of the BMC. The mean deviation for aortae with mild complicated lesions, i.e., those containing smaller amounts of calcium, was within the range of instrument precision.

Absorptiometry, Photon↗
PubMed1991

[Improved left ventricular function and perfusion at rest following transluminal coronary angioplasty].

The purpose of this study was to evaluate left ventricular function and perfusion at rest before and after percutaneous transluminal coronary angioplasty. In consecutive 69 patients in whom coronary stenoses were dilated, the radionuclide left ventricular ejection fraction at rest increased significantly. In 26 of these patients, the ejection fraction increased by at least 4%. In these patients, exercise-induced ischemic ST depression had been more pronounced than in the others. 36 other patients underwent 201TI myocardial scintigraphy before and after angioplasty. Twelve patients in whom pre-PTCA images had revealed regions with irreversible 201TI uptake defects, showed normal 201TI distribution patterns on post-PTCA scintigrams. Post-exercise 201TI uptake (representing myocardial perfusion and metabolic activity) during pre-PTCA exercise stress tests was significantly lower in these cases. It is concluded that PTCA can improve left ventricular function and perfusion at rest. This improvement is most obvious in patients with pronounced exercise-induced myocardial ischemia as diagnosed by typical ST segment depression and reduced thallium uptake.

Adult↗
PubMed1991

[Multiparametric analysis using radionuclide ventriculography in the assessment of left ventricular function following heart transplantation].

Left ventricular systolic and diastolic performance was evaluated by radionuclide angiography in 17 patients following cardiac transplantation and compared with normal persons. Both groups performed supine bicycle exercise during the investigation, the control group at 102 +/- 73 W and the transplanted patients at 61.2 +/- 15 W. The ejection fraction increased in the normal persons from 61 +/- 8 to 69 +/- 10% whereas in the transplanted patients it did not increase significantly. There were no relevant changes in systolic parameters during exercise in the transplant recipients. The changes in diastolic parameters were significantly smaller in transplant patients than in normals. After correction for heart rate-induced changes a significantly different time course of the systolic-diastolic sequence during the cardiac cycle became evident in the transplanted group at rest. During exercise the systolic-diastolic sequence during the cardiac cycle became similar in both groups. It is concluded that the reduced exercise capacity of patients in the late phase after cardiac transplantation is partially due to the absence of an EF increase and a limitation of diastolic reserve during exercise.

Adult↗
PubMed1990

Early immunoscintigraphic localisation of a mediastinal tumour with indium 111-DTPA CEA-specific F(ab')2 monoclonal antibody fragments (BW 431/31) using second tracer isocontour technique.

A female patient with steadily increasing carcinoembryonic antigen (CEA) serum levels of unknown origin was referred for immunoscintigraphy with indium 111-labelled CEA-specific monoclonal antibody. The procedure revealed a tumour, undetectable by conventional diagnostic methods. Anatomical landmarking using the second tracer isocontour technique allowed the distinction between an intra- or extrapulmonary lesion. Two months later, tumour infiltration along the aortic arch was confirmed by a targeted angio-CT scan. Upon surgery, the diagnosis was definitely established histologically (undifferentiated, solid large cell carcinoma, most probably arising from the bronchus), and staining by CEA-specific immunohistochemistry confirmed the presence of the CEA antigen.

Adult↗
PubMed1990

Is technetium-99 m-pyrophosphate scintigraphy valuable in the diagnosis of cardiac amyloidosis?

Amyloidosis is a systemic disease frequently involving the myocardium and leading to functional disturbances of the heart. Amyloidosis can mimic other cardiac diseases. A conclusive clinical diagnosis of cardiac involvement can only be made by a combination of different diagnostic methods. In 7 patients with myocardial amyloidosis we used a combined first-pass and static scintigraphy with technetium-99 m-pyrophosphate. There was only insignificant myocardial uptake of the tracer. The first-pass studies however revealed reduced systolic function in 4/7 patients and impaired diastolic function in 6/7 patients. Therefore, although cardiac amyloid could not be demonstrated in the static scintigraphy due to amyloid fibril amount and composition, myocardial functional abnormalities were seen in the first-pass study.

Amyloidosis↗