A 3D fiber model of the human brainstem

A new neuroanatomic approach to evaluate the fiber orientation in gross histological sections of the human brain was developed. Serial sections of a human brainstem were used to derive fiber orientation maps by analysis of polarized light sequences of these sections. Fiber inclination maps visualize angles of inclination, and fiber direction maps show angles of direction. These angles define vectors which can be visualized as RGB-colors. The serial sections were aligned to each other using the minimized Euclidian distance as fit criterion. In the 3D data set of the human brainstem the major fiber tracts were segmented, and three-dimensional models of these fiber tracts were generated. The presented results demonstrate that two kinds of fiber atlases are feasible: a fiber orientation atlas representing a vector in each voxel, which shows the nerve fiber orientation, and a volume-based atlas representing the major fiber tracts. These models can be used for the evaluation of diffusion tensor data as well as for neurosurgical planning.     

Upward creep of the heart in exercise thallium 201 single photon emission tomography: clinical relevance and a simple correction method

The upward creep of the heart during myocardial single photon emission tomography (SPET) acquisition has been reported as a frequent source of false-positive results. The aim of this study was to simplify the detection and correction of this upward creep and to estimate its clinical relevance during routine patient care. To recognize the upward heart motion a straight line was fitted to the upper and lower border of consecutively displayed tomographic projection images. In this way, vertical translation of at least 1 pixel in size could be detected easily. On the assumption of a slow but continuous upward motion a fast interpolation correction method was developed. From 100 consecutive, supine, ergometric exercise studies, 1, 2 or 3 pixels of upward creep were found in 16, 4 or 3 patients, respectively. It was found that an upward creep of at least 2 pixels (7/100 cases) led to evident, mostly antero-septal defects on quantitative bull's-eyes, whereas only upward creeps of 3 pixels or more (3/100 cases) produced false-positive diagnostic results. The simple correction method offered a sufficient compensation of image and/or bull's-eye artefacts. These clinical findings could be reproduced in a computer model. Thus, it can be stated that clinically significant upward creep of the heart during stress SPET acquisition is relatively rare; it may have been overestimated in the past, and its artificial effects can be corrected by a quick and simple algorithm.Research fellow of the Alexander von Humboldt Foundation working at Department of Nuclear Medicine, University Medical School Szeged, Hungary     

Pers?nliche Meinung?Der symptomatische Koronarpatient mit pathologischem operationsbedürftigen Koronarangiogramm

Zusammenfassung: Die Bypasschirurgie hat sich bei exzellenten Kurz- und Langzeitergebnissen als fester Bestandteil in der Therapie der koronaren Herzerkrankung etabliert. Zur Anpassung an eine veränderte Patientenstruktur mit einem hohen Anteil an Hochrisikopatienten sind zunehmend minimalinvasive chirurgische Techniken in der Herzchirurgie zum Einsatz gekommen. Ergänzend zu chirurgischen Maßnahmen werden molekularbiologische Techniken in der Primär- und Sekundärtherapie der koronaren Herzkrankheit eingesetzt. Abstract: Bypass surgery has become a routine procedure for the treatment of coronary artery disease. Due to increase numbers of high-risk patients minimally invasive techniques were introduced in cardiac surgery with excellent clinical results. In addition molecular methods have been applied for primary and secondary treatment of coronary artery disease.     

Protein synthesis inhibiting clindamycin improves outcome in a mouse model of Staphylococcus aureus sepsis compared with the cell wall active ceftriaxone

OBJECTIVE: The release of proinflammatory components from bacteria depends on the mode of action of the antibacterial therapy used. We studied whether this influences mortality in experimental sepsis. DESIGN: In a lethal murine model of Staphylococcus aureus sepsis, animals were randomly assigned to receive the protein synthesis inhibitor clindamycin (CLI) or the beta-lactam ceftriaxone (CRO). SETTING: Therapy was introduced subcutaneously 5 hrs after intraperitoneal injection of 10 colony forming units of S. aureus American Type Culture Collection 29213 and was continued every 8 hrs for 3 days. MEASUREMENTS AND RESULTS: Survival was higher in mice receiving CLI (29/50 animals [58%]) than in mice receiving CRO (16/50 animals [32%]; p =.015). Mice treated with CRO died earlier than mice receiving CLI (p =.002). Eight hours after the first antibiotic dose, the motor performance of mice receiving CRO had deteriorated more than it did for mice receiving CLI (p =.009). Higher levels of tumor necrosis factor-alpha were measured in serum (p =.027) and peritoneal fluid (p =.001) of CRO-treated mice. In vitro, CLI released smaller amounts of staphylococcal enterotoxin A than CRO. CONCLUSIONS: Antibiotic treatment of Gram-positive sepsis with a protein synthesis inhibitor decreases morbidity and mortality compared with a bacteriolytic compound. This may be caused by a reduction of the concentrations of proinflammatory/toxic bacterial components and cytokines.     

Treatment of in-stent restenosis with sirolimus-eluting-stents: results from the prospective German Cypher stent registry

Aims  Drug-eluting stents have been reported to effectively reduce in-stent restenosis (ISR). However, the effectiveness and safety have yet been investigated only in small trials or case series. The aim of this prospective large scale registry was to show that treatment of ISR with sirolimus eluting stents (SES) is safe, effective and feasible in daily routine. Methods and results  The German Cypher registry prospectively enrolled 6,555 patients undergoing implantation with SES for various indications, including 1,533 patients treated for ISR. Follow-up data (median 6.6 months) of this cohort was available for 1,531 patients (99.8%). Of these patients 75.8% were male. Of these patients 36.5% (n = 552) presented with acute coronary syndromes. In total, 1,932 SES were used with successful implantation in 98.9%. MI during hospitalization was observed in 0.7% (n = 11) while in-hospital mortality was only 0.1% (n = 2). MACE-rate at follow-up was 13.8% (n = 211) including a mortality of 1.3% (n = 20) and MI in 1.9% (n = 29). Total revascularization procedures including CABG (1.7%) were necessary in 12.3% (n = 186). Target vessel revascularization (TVR) rate was 9.3% (n = 139) and thus similar to patients with de novo lesions (8.1%, P = 0.69). Ten patients (0.65%) suffered from subacute stent thrombosis Vs. 0.24% observed in patients with de novo lesions (P = 0.03). Conclusion  This large registry confirms that treatment of ISR with sirolimus-eluting-stents is effective and save with good clinical results at index procedure and follow-up. TVR was not different from de novo lesions.     

Native infective endocarditis: Which determinants of outcome remain after surgical treatment?

Summary Surgical therapy of native infective endocarditis is still considered as a particular challenge, due to remaining morbidity and mortality up to 20%. Further risk analysis and characterization of clinical features is of great importance for further improvement of surgical results. The aim of this retrospective study was a risk analysis concerning clinical features of the pre–, intra– and postoperative period. Between 02/1997 and 12/2003, 165 patients (130 male, 35 female, age 55.5 ± 13.8 years) were referred for surgical therapy of infective endocarditis at our institution. Preoperative, intraoperative and postoperative features were evaluated for their influence on the early postoperative course and the mid–term follow–up. In the majority of patients (pts) the aortic valve was infected (n = 83, 50.3% of pts), followed by mitral valve (n = 33; 20.0%), tricuspid valve (n = 10, 6.0%) and pulmonary valve (n = 2; 1.2%). Double valve affection was recorded in 37 pts (22.4%). Streptococci (n = 66, 40.0%) and staphylococci (n = 66, 40.0%) were the most common pathogens. The overall hospital mortality rate was 10.9% (n = 18), during follow–up (mean follow–up 3.3 ± 2.5 years) a further 20 pts (12.1%) died. Main predictors for hospital mortality in multivariate analysis were older age (p = 0.01), prolonged ICU stay, prolonged intubation (p = 0.03; p = 0.02) and the continuous postoperative need of alpha–catecholamine medication (p < 0.01). Significant predictors of overall mortality were older age (> 70 years) and diabetes (p = 0.03; p = 0.03). Reinfection occurred in 6.1% of patients (n = 10). Actuarial freedom from recurrent infection was 97% at 1 year and 93.9% at 5 years. Surgical therapy of infective endocarditis is associated with good clinical results in the early and mid–term follow–up. Predictors of outcome particular include preoperative risk constellation or comorbidity (age, diabetes) and variables of the immediate postoperative course.