Search PubMed⌕ Search

Biomedical subjects

H Mannebach

Publications and source records attributed to H Mannebach.

At least 37 records · Page 2Linked to original sources
PubMed1997

Tuberculosis in heart transplant recipients.

STUDY OBJECTIVES: To clarify the prevalence and factors associated with tuberculosis, as well as patient survival in heart transplant recipients. DESIGN: A retrospective review of case records of all heart transplant recipients from March 1989 to February 1996 during a 7-year period. SETTING AND PATIENTS: During the period reviewed, 727 orthotopic heart transplantations were performed in 716 patients at the Heart Center Northrhine-Westphalia, Germany. RESULTS: Tuberculosis was proved in seven (1%) patients (four men/three women; age, 33 to 71 years; two miliary lesions, three pulmonary lesions, and two urogenital lesions). None of them had primary history of tuberculosis. Tuberculin skin tests were not performed before transplantation because there were no lesions indicating primary infection of turberculosis. The immunosuppressive regimen was based on double-drug (cyclosporine + azathioprine) therapy. Immunosuppression had been intensified by methylprednisolone pulses at least three times in those seven patients, and prednisone had been used orally in six of seven patients. Tuberculosis developed from 2.5 to 41 months after transplantation. Tuberculosis was found by routine examinations in four of seven patients. Diagnoses were made with both direct microscopy and cultures in six patients, and by histologic study in one. Treatment consisted of isoniazid, rifampicin, ethambutol, and pyrazinamide. Two patients with miliary lesions were treated with four drugs, and the others were treated with three drugs. Isoniazid was used in all patients. Rifampicin, which decreases cyclosporine serum levels, was not used from the beginning in one patient and treatment with it was stopped halfway in another patient because low cyclosporine level had induced rejection. Six of the seven patients are doing well while receiving antituberculous therapy. One patient died with miliary tuberculosis as a cause of death. CONCLUSIONS: The prevalence of tuberculosis in heart transplant recipients was higher than that in the general population. We recommend that a high degree of clinical suspicion is maintained for tuberculosis in heart transplant recipients with meticulous follow-up, and that the treatment of tuberculosis has to be with meticulous care, especially during the use of rifampicin.

Adult↗
PubMed1996

Predictors of unsuccessful outcome after percutaneous mitral valvulotomy including a new echocardiographic scoring system.

BACKGROUND AND AIMS OF THE STUDY: Percutaneous mitral valvulotomy has been shown to be an accept able alternative to surgery as treatment for selected patients with severe mitral stenosis. Uncertainty still exists regarding predictors of unsuccessful outcome. MATERIALS AND METHODS: 308 patients with severe mitral stenosis underwent Inoue single balloon valvulotomy over a 48-month period and were followed up for a mean of 14.5 +/- 16.8 months (range one to 64 months). Two hundred and sixty-seven (Group I) improved clinically and remained stable throughout the follow up, while subsequent surgery was required in 41 (Group II) after 38.2 +/- 143.5 days (range one to 1,212). Clinical and echocardiographic parameters of the two groups were compared to find significant predictors of an unsuccessful outcome. RESULTS: Significant differences between the groups were observed for NYHA class (2.7 +/- 0.6 vs. 2.9 +/- 0.6, p < 0.05), mitral valve area (1.0 +/- 0.3 vs. 0.9 +/- 0.2 cm2, p < 0.01), left atrial end-systolic dimension by echo (51.3 +/- 8.0 vs. 55.4 +/- 10.2 mm, p < 0.01) and an echocardiographic scoring system including grading for eccentricity of the mitral orifice and distribution of commissural calcification (7.5 +/- 2.0 for Group I and 8.7 +/- 2.0 for Group II, p < 0.001). CONCLUSIONS: Mitral valves that are more likely to have an unsuccessful outcome can be identified by hemodynamic, clinical and echocardiographic criteria, including grading for eccentricity of the mitral orifice and distribution of commissural calcification.

Adult↗
PubMed1996

Ultrasound examination of stenotic mitral valves: an in vitro study.

To determine the feasibility of currently used, intravascular ultrasound catheters (12.5 and 20 MHz, 6F and 9F, Boston Scientific Corp., Watertown, MA) for mitral valve disease, ten excised mitral valves from patients with severe mitral stenosis were examined. The specimens were fixed in a glass cylinder perfused with water. The valves were planimetered with the intravascular ultrasound system and investigated regarding pathomorphological changes. The depth field of penetration was between 1.5 and 2 cm (3 to 4 cm diameter) in the 20 MHz catheter and between 2 and 2.5 cm (4 to 5 cm diameter) in the 12.5 MHz catheter. A good correlation of the experimentally recorded valve areas could be ascertained with the Gorlin formula (r = .71, P < .05), the Doppler echocardiography method (r = .69, time method (r = .75, p < .05), and with the two-dimensional echocardiography method (r = .69, P < .05). These results show a sufficient feasibility of the currently used, intravascular ultrasound catheters and enable further steps to be taken with regard to evaluating mitral valve morphology in vivo.

Aged↗
PubMed1996

Pathomorphological characteristics of resected mitral valves after unsuccessful valvuloplasty.

OBJECTIVE: Percutaneous mitral valvuloplasty has been shown to be an acceptable alternative to surgery as treatment for selected patients with severe mitral stenosis. We examined hemodynamic, echocardiographic, and pathomorphologic findings in a series of 308 patients undergoing balloon valvuloplasty, 41 of whom underwent subsequent surgery, in search of possible predictors of an unsuccessful outcome. INTERVENTION AND RESULTS: Patients with severe mitral stenosis underwent Inoue single ballon valvuloplasty over a 48-month period and had follow-up for a mean of 14.5+/-16.8 months (range 1 to 64 months). Of the 308 patients, 267 (Group I) were clinically improved and stable throughout follow-up, while subsequent surgery was required in 41 (Group II) after 38.2+/-143.5 days (range 1 to 1212). Significant differences between the groups were observed for NYHA class (2.7+/-0.6 vs 2.9+/-0.6, p<0.05), mitral valve area (1.0+/-0.3 vs 0.9+/-0.2 cm2, p<0.01) and left atrial endsystolic dimension by echo (51.3+/-8.0 vs 55.4+/-10.2 mm, p<0.01). Two of the 41 Group II patients underwent surgery for left to right shunting, 1 for tamponade and 2 were lost to follow-up. The excised mitral valves of the remaining 36 patients all showed calcification and/or fibrosis: 9 homogenous, 5 non-homogenous; 19 were classified as having a funnel-shaped deformity, and 3 did not fit into a discrete category. Among the funnel-shaped valves, 13 had a tear versus 6 where dilation was primarily accomplished by stretching. Only one of 9 valves with homogenous calcification was torn, whereas a tear was noted in 3 of the 5 with non-homogenous calcification. CONCLUSION: Funnel-shaped valves and those with non-homogenous distribution of calcification and/or fibrosis appear to be least suitable for balloon valvuloplasty.

Adult↗
PubMed1995

[Clinical significance of the cardiovascular risk factor fibrinogen in secondary prevention].

Seven prospective, epidemiological studies indicate plasma fibrinogen levels (over 300-350 mg/dl) as an important, independent cardiovascular risk factor for subsequent myocardial infarction and stroke. Furthermore, several clinical studies revealed an association between fibrinogen and both the angiographic and clinical degree of coronary heart disease. In addition, a significant relation of fibrinogen with the number of occluded coronary vessels was found. The following pathophysiologic mechanism are of particular importance: Fibrinogen is a main determinant of plasma viscosity and red cell aggregation. Both phenomena deteriorate blood fluidity especially in the microcirculation. Fibrinogen plays a central role in platelet aggregation and performs an essential substrate in the coagulation cascade. Thus, high fibrinogen levels may favor a hypercoagulable state resulting in final thrombotic events of cardiovascular disease. Fibrinogen is also involved in atherogenesis by stimulating proliferation and migration of smooth muscle cells. Several determinants of fibrinogen levels are known. Smoking is the strongest one in healthy persons. This clinically important effect is dose related. Consequently, cessation of smoking is a major step to lower fibrinogen and subsequently the individual cardiovascular risk. Reduction of overweight and maintenance of regular physical activity are further nonpharmacologic means. Fibrates decrease fibrinogen about 10-30% on an average. Finally, intermittent low-dose Urokinase for end-stages of coronary artery disease and LDL-apheresis (HELP) represent additional approaches to reduce fibrinogen.

Adult↗
PubMed1995

Evidence against heterozygous coagulation factor V 1691 G-->A mutation with resistance to activated protein C being a risk factor for coronary artery disease and myocardial infarction.

The aim of our study was to determine the prevalence of the factor V mutation (position 1691 G-->A) in patients with angiographically diagnosed coronary artery disease and myocardial infarction and, as a control, in blood donors. This mutation has already been proved to be the main genetic risk factor for venous thrombosis. In order to detect this mutation in exon 10 of the factor V gene we established a microtiter plate based hybridization assay for the specific detection of wild-type and mutant sequences in factor V gene segments, obtained after amplification by polymerase chain reaction. This test enables us to screen a large number of samples. The mutation was detected in 29 of 317 coronary artery disease (CAD) patients (9.1%) and 18 of 190 blood donors (9.5%) investigated. The mean activated protein C resistance ratios were 3.18 and 3.11, with nearly identical distribution. No increased prevalence of the factor V mutation was found in the CAD group. In 10 of 29 CAD patients (35%) with the factor V 1691 G-->A mutation and in 124 of 288 CAD patients without the mutation (43%) there was a history of myocardial infarction. From our data we conclude that there is no increased risk of developing coronary atheroma or consecutive myocardial infarction resulting from the factor V mutation with protein C resistance.

Adenine↗
PubMed1995

[Fibrinogen and leukocyte number in coronary heart disease. Correlation with angiography and clinical degree].

In 302 consecutively patients fibrinogen (Clauss method) and leucocyte count were related to the angiographic and clinical degree of coronary atherosclerosis. Fibrinogen (mg/dl) was statistically higher compared to control (C, 267 +/- 55) in patients with one-vessel disease (1-vd (306 +/- 67), 2-vd (331 +/- 73), and 3-vd (328 +/- 62)). Patients with coronary sclerosis (Scl, luminal irregularities and/or stenosis under 50%) showed a tendency to higher fibrinogen levels (291 +/- 58) as compared to controls. Leucocyte count (10(9)/L) compared to C (6.7 +/- 1.8) was significantly higher in 1-vd (7.6 +/- 2.0) and 2-vd (7.6 +/- 1.9). A subgroup analysis was performed with 100 patients having severe forms of angina pectoris (AP III according to the CCS classification, unstable angina). Hundred-sixteen patients with unstable angina (390 +/- 79), particularly with angina at rest during the last 48 h were characterized by the highest fibrinogen values (423 +/- 89, class III B/C Braunwald). Leucocyte count in patients with stable angina (7.2 +/- 1.4) and angina at rest (9.3 +/- 2.7) was significantly higher as compared to control (6.7 +/- 1.8). Hyperfibrinogenemia and relative leucocytosis correlate with the angiographic and clinical extent of coronary artery disease and may offer evidence of a higher degree of thrombogenesis associated with components of inflammation.

Adult↗
PubMed1995

Heart transplantation at the Heart Center North Rhine-Westphalia in Bad Oeynhausen -- 1995 report.

Since March 1989, 713 heart transplants were performed at our center, limited only by donor availability. The induction of immunosuppression was based on double-drug therapy (CsA + Aza) without the use of mono- or polyclonal antibodies. Whenever possible, maintenance immunosuppression was based on CsA and Aza without steroids. Monitoring in adult patients was based on endomyocardial biopsies only during the first 12 months. In the pediatric patient group, only noninvasive diagnostic procedures were performed. The current 1- and 5-year survival rates for heart transplant patients are 80% and 75%, respectively.

Adolescent↗
PubMed1993

Reconstructing medical problem solving competence: MACCORD.

The building of medical knowledge-based systems involves the reconstruction of methodological principles and structures within the various subdomains of medicine. ACCORD is a general methodology of knowledge-based systems, and MACCORD its application to medicine. MACCORD represents the problem solving behavior of the medical expert in terms of various types of medical reasoning and at various levels of abstraction. With MACCORD the epistemic and cognitive processes in clinical medicine can be described in formal terminology, covering the entire diversity of medical reasoning. MACCORD is close enough to formalization to make a significant contribution to the fields of medical knowledge acquisition, medical didactics and the analysis and application of medical problem solving methods.

Artificial Intelligence↗
PubMed1992

Therapy for acute vascular complications in percutaneous transluminal coronary angioplasty with the autoperfusion balloon catheter.

Prolonged dilatation with an autoperfusion balloon catheter (APBC) (High-Flow-CPC-Mainz (Schneider) in 23 cases and Stack Perfusion (ACS) in 50 cases) was carried out in 73 patients (60 men, 13 women, mean age 59.3 +/- 8.8 years) with acute vascular complications occurring during PTCA (25 occlusive dissections (34%), five thrombotic occlusions (7%), 42 non-occlusive dissections (58%) and one non-occlusive thrombus with reduction of flow (1%)) in order to avoid stent implantation or emergency bypass surgery. On average 1.5 +/- 0.8 inflations were carried out per patient with a mean maximum inflation time of 14.1 +/- 8.4 min and a mean total inflation time of 16.8 +/- 12.3 min. In 61 patients (83.5%), the vascular complication could be controlled successfully with APBC, but in 12 APBC was not successful. Eight patients (11%) had emergency surgery. A stent was implanted in three patients (4.1%), and one suffered an acute myocardial infarction. Out of the 61 patients with positive result after prolonged dilatation, the hospital phase was uncomplicated in 53 (86.9%), five (8.2%) suffered an infarct with a maximum rise in CK of 350 U.l-1, two with multivessel disease had elective operations and one was dilated a second time because of a subacute reocclusion. Our experience indicates that when an acute vascular complication occurs, prolonged dilatation with an APBC is good interventional therapy avoiding stent implantation or emergency bypass surgery. However, new techniques cannot always replace surgery so an emergency bypass operation may still be necessary.

Adult↗