Three-dimensional printing creates models for surgical planning of aortic valve replacement after previous coronary bypass grafting.

PURPOSE Resternotomy for aortic valve replacement in patients with previous coronary artery bypass grafting and an internal mammary artery graft may be a surgical problem. Thus, we are exploring the effect of using rapid prototyping techniques for surgical planning and intraoperative orientation during aortic valve replacement after previous coronary artery bypass grafting (CABG). DESCRIPTION As a proof of concept, we studied a patient who had undergone CABG 5 years earlier. At that time the patient received a left internal mammary artery graft to the left anterior descending artery and a venous graft to the right coronary artery. Now the patient required aortic valve replacement due to symptomatic aortic valve stenosis. The left internal mammary artery bypass and the right coronary artery bypass were patent and showed good flow in the angiography. The patient was examined by 128-slice computed tomography. The image data were visualized and reconstructed. Afterwards, a replica showing the anatomic structures was fabricated using a rapid prototyping machine. EVALUATION Using data derived from 128-slice computed tomography angiography linked to proprietary software, we were able to create three-dimensional reconstructions of the vascular anatomy after the previous CABG. The models were sterilized and taken to the operating theatre for orientation during the surgical procedure. CONCLUSIONS Stereolithographic replicas are helpful for choosing treatment strategies in surgical planning and for intraoperative orientation during reoperations of patients with previous CABG.

Pädagogisches Handeln als Balancing zwischen Theorie und Praxis. Beiträge zur Wirksamkeitsforschung im pädagogisch-psychologischen Kontext

Das Verhältnis zwischen Theorie und Praxis ist nach wie vor ungeklärt. Dennoch muss sich die Pädagogik um die Klärung des Theorie-Praxisbezugs bemühen. Die vielfach diskutierten Positionen, Theorie wirke direkt auf Praxis oder praktisches Handeln müsse theoriegeleitet erfolgen müssen kritisch hinterfragt werden. Mit der im Titel gewählten Metapher des Balancing soll zum Ausdruck gebracht werden, dass der Einflussgrad theoriegeleiteten Argumentierens auf reflektiertes praktisches Handeln im Hinblick auf personen- und situationsadäquates Handeln in der Praxis variiert. Der vorliegende Band versammelt Beiträge, die unterschiedliche Positionen des Theorie-Praxisbezugs vorstellen und diskutieren. Die Beiträge des vorliegenden Bandes thematisieren vier Felder pädagogischen Handelns, nämlich „Unterricht“ (Rolf Dubs, Philippe Patry, Josef Thonhauser, Alfred Weinberger, Sieglinde Weyringer), „Schul- und Unterrichtsentwicklung“ (Eric Patry, Franz Riffert und Andreas Paschon, S.V. Subramanian, Herbert Schwetz), „Studium und Lehrerbildung“ (Hermann Astleitner, Ferdinand Eder und Franz Hofmann, Tina Hascher, Christiane Spiel et al.) und „Intervention und Beratung“ (Angela Gastager, Meinrad Perrez, Kestutis Pukelis). In jedem Handlungsfeld werden je spezifische Blickwinkel auf die Beziehungen zwischen Theorie und Praxis eröffnet.

Ueber die Veredlung der Menschen besonders der Juden durch die Regierung : nebst e. Sendschreiben an d. Verf. d. Bemerkungen über des Hrn. Geheimen Finanzrath's Jakobsohn Vorstellung an den Fürsten Primas

von [August Ferdinand] Lueder

La Force d'Israel vers et pour la renaissance du judaisme

par S. Ferdinand-Lop

Geschichte, Religionsgrundsätze und staatsbürgerliche Verhältnisse der Juden : ein Noth- u. Hülfsbüchlein f. d. gegenwärtige Zeit

von Ferdinand Schubert

Der Wahrheit eine Gasse! : Eine Abrechnung mit d. Judentum u. seinen Helfern

von Ferdinand Werner

Bibliotheca juris Rabbinica et Saracenorum Arabica

instructa a Carolo Ferd. Hommelio

Abhandlung über den Ursprung der Beschneidung bei wilden und halbwilden Völkern mit Beziehung auf die Beschneidung der Israeliten : mit e. Kritik von C. Chr. v. Flatt begleitet

verf. von J. H. F. v. Autenrieth

Patriotische Gedanken über den Zustand der Juden überhaupt, vorzüglich der Judenschaft in der Reichsstadt Friedberg

[Verf.[[Elektronische Ressource]] : F. R. C. D. Sch.]

Influence of screw augmentation in posterior dynamic and rigid stabilization systems in osteoporotic lumbar vertebrae: a biomechanical cadaveric study.

STUDY DESIGN Biomechanical cadaveric study. OBJECTIVE To determine whether augmentation positively influence screw stability or not. SUMMARY OF BACKGROUND DATA Implantation of pedicle screws is a common procedure in spine surgery to provide an anchorage of posterior internal fixation into vertebrae. Screw performance is highly correlated to bone quality. Therefore, polymeric cement is often injected through specifically designed perforated pedicle screws into osteoporotic bone to potentially enhance screw stability. METHODS Caudocephalic dynamic loading was applied as quasi-physiological alternative to classical pull-out tests on 16 screws implanted in osteoporotic lumbar vertebrae and 20 screws in nonosteoporotic specimen. Load was applied using 2 different configurations simulating standard and dynamic posterior stabilization devices. Screw performance was quantified by measurement of screwhead displacement during the loading cycles. To reduce the impact of bone quality and morphology, screw performance was compared for each vertebra and averaged afterward. RESULTS All screws (with or without cement) implanted in osteoporotic vertebrae showed lower performances than the ones implanted into nonosteoporotic specimen. Augmentation was negligible for screws implanted into nonosteoporotic specimen, whereas in osteoporotic vertebrae pedicle screw stability was significantly increased. For dynamic posterior stabilization system an increase of screwhead displacement was observed in comparison with standard fixation devices in both setups. CONCLUSION Augmentation enhances screw performance in patients with poor bone stock, whereas no difference is observed for patients without osteoporosis. Furthermore, dynamic stabilization systems have the possibility to fail when implanted in osteoporotic bone.

Do optic nerve head and visual field parameters in patients with obstructive sleep apnea syndrome differ from those in control individuals?

BACKGROUND It has been suggested that sleep apnea syndrome may play a role in normal-tension glaucoma contributing to optic nerve damage. The purpose of this study was to evaluate if optic nerve and visual field parameters in individuals with sleep apnea syndrome differ from those in controls. PATIENTS AND METHODS From the records of the sleep laboratory at the University Hospital in Bern, Switzerland, we recruited consecutive patients with severe sleep apnea syndrome proven by polysomnography, apnea-hypopnea index >20, as well as no sleep apnea controls with apnea-hypopnea index <10. Participants had to be unknown to the ophtalmology department and had to have no recent eye examination in the medical history. All participants underwent a comprehensive eye examination, scanning laser polarimetry (GDx VCC, Carl Zeiss Meditec, Dublin, California), scanning laser ophthalmoscopy (Heidelberg Retina Tomograph II, HRT II), and automated perimetry (Octopus 101 Programm G2, Haag-Streit Diagnostics, Koeniz, Switzerland). Mean values of the parameters of the two groups were compared by t-test. RESULTS The sleep apnea group consisted of 69 eyes of 35 patients; age 52.7 ± 9.7 years, apnea-hypopnea index 46.1 ± 24.8. As controls served 38 eyes of 19 patients; age 45.8 ± 11.2 years, apnea-hypopnea index 4.8 ± 1.9. A difference was found in mean intraocular pressure, although in a fully overlapping range, sleep apnea group: 15.2 ± 3.1, range 8-22 mmHg, controls: 13.6 ± 2.3, range 9-18 mmHg; p<0.01. None of the extended visual field, optic nerve head (HRT) and retinal nerve fiber layer (GDx VCC) parameters showed a significant difference between the groups. CONCLUSION Visual field, optic nerve head, and retinal nerve fiber layer parameters in patients with sleep apnea did not differ from those in the control group. Our results do not support a pathogenic relationship between sleep apnea syndrome and glaucoma.