Refine
Has Fulltext
- yes (26)
Is part of the Bibliography
- yes (26)
Year of publication
Document Type
- Journal article (26)
Keywords
- evidence-based medicine (3)
- guidelines (3)
- indication for surgery (3)
- laparoscopic ventral hernia repair (3)
- neutrophils (3)
- perioperative management (3)
- acute ischemic stroke (2)
- immunohistochemistry (2)
- mechanical thrombectomy (2)
- 28 (1)
Institute
- Klinik und Poliklinik für Unfall-, Hand-, Plastische und Wiederherstellungschirurgie (Chirurgische Klinik II) (6)
- Neurologische Klinik und Poliklinik (5)
- Institut für diagnostische und interventionelle Neuroradiologie (ehem. Abteilung für Neuroradiologie) (4)
- Klinik und Poliklinik für Allgemein-, Viszeral-, Gefäß- und Kinderchirurgie (Chirurgische Klinik I) (3)
- Medizinische Klinik und Poliklinik II (3)
- Institut für Anorganische Chemie (2)
- Institut für Molekulare Infektionsbiologie (2)
- Klinik und Poliklinik für Psychiatrie, Psychosomatik und Psychotherapie (2)
- Lehrstuhl für Orthopädie (2)
- Medizinische Klinik und Poliklinik I (2)
- Physiologisches Institut (2)
- Theodor-Boveri-Institut für Biowissenschaften (2)
- Center for Computational and Theoretical Biology (1)
- Institut für Anatomie und Zellbiologie (1)
- Institut für Organische Chemie (1)
- Institut für Virologie und Immunbiologie (1)
- Institut für diagnostische und interventionelle Radiologie (Institut für Röntgendiagnostik) (1)
- Kinderklinik und Poliklinik (1)
- Klinik und Poliklinik für Anästhesiologie (ab 2004) (1)
- Klinik und Poliklinik für Strahlentherapie (1)
- Lehrstuhl für Tissue Engineering und Regenerative Medizin (1)
- Neurochirurgische Klinik und Poliklinik (1)
- Physikalisches Institut (1)
The Gram-negative Epsilonproteobacterium Campylobacter jejuni is currently the most prevalent bacterial foodborne pathogen. Like for many other human pathogens, infection studies with C. jejuni mainly employ artificial animal or cell culture models that can be limited in their ability to reflect the in-vivo environment within the human host. Here, we report the development and application of a human three-dimensional (3D) infection model based on tissue engineering to study host-pathogen interactions. Our intestinal 3D tissue model is built on a decellularized extracellular matrix scaffold, which is reseeded with human Caco-2 cells. Dynamic culture conditions enable the formation of a polarized mucosal epithelial barrier reminiscent of the 3D microarchitecture of the human small intestine. Infection with C. jejuni demonstrates that the 3D tissue model can reveal isolate-dependent colonization and barrier disruption phenotypes accompanied by perturbed localization of cell-cell junctions. Pathogenesis-related phenotypes of C. jejuni mutant strains in the 3D model deviated from those obtained with 2D-monolayers, but recapitulated phenotypes previously observed in animal models. Moreover, we demonstrate the involvement of a small regulatory RNA pair, CJnc180/190, during infections and observe different phenotypes of CJnc180/190 mutant strains in 2D vs. 3D infection models. Hereby, the CJnc190 sRNA exerts its pathogenic influence, at least in part, via repression of PtmG, which is involved in flagellin modification. Our results suggest that the Caco-2 cell-based 3D tissue model is a valuable and biologically relevant tool between in-vitro and in-vivo infection models to study virulence of C. jejuni and other gastrointestinal pathogens.
Operative treatment of ruptured pubic symphysis by plating is often accompanied by complications. Trans-obturator cable fixation might be a more reliable technique; however, have not yet been tested for stabilization of ruptured pubic symphysis. This study compares symphyseal trans-obturator cable fixation versus plating through biomechanical testing and evaluates safety in a cadaver experiment. APC type II injuries were generated in synthetic pelvic models and subsequently separated into three different groups. The anterior pelvic ring was fixed using a four-hole steel plate in Group A, a stainless steel cable in Group B, and a titan band in Group C. Biomechanical testing was conducted by a single-leg-stance model using a material testing machine under physiological load levels. A cadaver study was carried out to analyze the trans-obturator surgical approach. Peak-to-peak displacement, total displacement, plastic deformation and stiffness revealed a tendency for higher stability for trans-obturator cable/band fixation but no statistical difference to plating was detected. The cadaver study revealed a safe zone for cable passage with sufficient distance to the obturator canal. Trans-obturator cable fixation has the potential to become an alternative for symphyseal fixation with less complications.
Ischemic stroke caused by thromboembolic occlusion of large cerebral arteries, such as the internal carotid (ICA) and/or the middle cerebral artery (MCA), is treated by mechanical thrombectomy (MT). MT allows salvage of the vessel-occluding thrombemboli, which most frequently originate from the left atrium or the left ventricle of the heart or from sites of plaque rupture within large arteries above the heart. Clot composition may influence the efficacy of (intravenous) thrombolysis and MT, respectively. We analyzed 37 human thrombemboli obtained from acute ischemic stroke patients during MT with special emphasis on histological staining of neutrophils and neutrophil extracellular traps (NETs). We found neutrophils as the main cellular component of cerebral thrombemboli but encountered considerable morphological heterogeneity. Neutrophils accumulated in the border region of fibrin-rich structures indicating possible interaction of neutrophils with distinct structural thrombembolus components. Web-like NETs were found in 35 of 37 thrombemboli in varying amounts. NETs were almost exclusively found within fibrin-rich areas. Importantly, stroke etiology, age and present oral anticoagulation was associated with morphological patterns and the amount of neutrophils. Correlation of histological data and imaging data revealed that relative Hounsfield units of cerebral thrombemboli positively correlated with the amount of red blood cells. In summary, our results demonstrate that neutrophils and NETs are substantial constituents of cerebral thrombemboli and contribute to their structural complexity.
Background
For improved outcomes in total knee arthroplasty (TKA) correct implant fitting and positioning are crucial. In order to facilitate a best possible implant fitting and positioning patient-specific systems have been developed. However, whether or not these systems allow for better implant fitting and positioning has yet to be elucidated. For this reason, the aim was to analyse the novel patient-specific cruciate retaining knee replacement system iTotal (TM) CR G2 that utilizes custom-made implants and instruments for its ability to facilitate accurate implant fitting and positioning including correction of the hip-knee-ankle angle (HKA).
Methods
We assessed radiographic results of 106 patients who were treated with the second generation of a patient-specific cruciate retaining knee arthroplasty using iTotal\(^{TM}\) CR G2 (ConforMIS Inc.) for tricompartmental knee osteoarthritis (OA) using custom-made implants and instruments. The implant fit and positioning as well as the correction of the mechanical axis (hip-knee-ankle angle, HKA) and restoration of the joint line were determined using pre- and postoperative radiographic analyses.
Results
On average, HKA was corrected from 174.4 degrees +/- 4.6 degrees preoperatively to 178.8 degrees +/- 2.2 degrees postoperatively and the coronal femoro-tibial angle was adjusted on average 4.4 degrees. The measured preoperative tibial slope was 5.3 degrees +/- 2.2 degrees (mean +/- SD) and the average postoperative tibial slope was 4.7 degrees +/- 1.1 degrees on lateral views. The joint line was well preserved with an average modified Insall-Salvati index of 1.66 +/- 0.16 pre- and 1.67 +/- 0.16 postoperatively. The overall accuracy of fit of implant components was decent with a measured medial overhang of more than 1 mm (1.33 mm +/- 0.32 mm) in 4 cases only. Further, a lateral overhang of more than 1 mm (1.8 mm +/- 0.63) (measured in the anterior-posterior radiographs) was observed in 11 cases, with none of the 106 patients showing femoral notching.
Conclusion
The patient-specific iTotal\(^{TM}\) CR G2 total knee replacement system facilitated a proper fitting and positioning of the implant components. Moreover, a good restoration of the leg axis towards neutral alignment was achieved as planned. Nonetheless, further clinical follow-up studies are necessary to validate our findings and to determine the long-term impact of using this patient- specific system.
Fluorinated groups are essential for drug design, agrochemicals, and materials science. The bis(trifluoromethyl)amino group is an example of a stable group that has a high potential. While the number of molecules containing perfluoroalkyl, perfluoroalkoxy, and other fluorinated groups is steadily increasing, examples with the N(CF\(_{3}\))\(_{2}\) group are rare. One reason is that transfer reagents are scarce and metal-based storable reagents are unknown. Herein, a set of Cu\(^{I}\) and Ag\(^{I}\) bis(trifluoromethyl)amido complexes stabilized by N- and P-donor ligands with unprecedented stability are presented. The complexes are stable solids that can even be manipulated in air for a short time. They are bis(trifluoromethyl)amination reagents as shown by nucleophilic substitution and Sandmeyer reactions. In addition to a series of benzylbis(trifluoromethyl)amines, 2-bis(trifluoromethyl)amino acetate was obtained, which, upon hydrolysis, gives the fluorinated amino acid N,N-bis(trifluoromethyl)glycine.
Hintergrund
Die Symphysensprengung mit entsprechender Diastase kann durch eine Symphysenplatte stabilisiert werden.
Fragestellung
Welche Beckenverletzungen werden mit einer Symphysenplatte stabilisiert und wie ist das Outcome?
Material und Methoden
Retrospektive Auswertung von 64 Patienten über einen Untersuchungszeitraum von 24 Monaten.
Ergebnisse
Es waren 56 Patienten männlich, 8 weiblich und das mittlere Alter betrug 44 Jahre (SD ± 17). Unfälle im Straßenverkehr waren der führende Grund für die Beckenverletzung. Die Verteilung nach AO-Klassifikation zeigte sich wie folgt: 14-mal B1-, 10-mal B2-, 5‑mal B3-, 23-mal C1-, 9‑mal C2- und 3‑mal C3-Verletzungen. Die Verteilung nach Young und Burgess ergab: 9‑mal APC-I-, 18-mal APC-II-, 13-mal APC-III-, 9‑mal LC-I-, 3‑mal LC-II-, 2‑mal LC-III- und 10-mal VS-Verletzungen. Der mittlere Injury Severity Score (ISS) betrug 32 und die mittlere stationäre Verweildauer 29 Tage (pos. Korrelation p ≤ 0,001). Im Verlauf war eine radiologische Implantatlockerung bei 52 Patienten nachweisbar. Therapierelevante Komplikationen gab es in 14 Fällen. Hierbei war das Implantatversagen (n = 8) der Hauptgrund für eine operative Revision.
Diskussion
Obwohl die radiologische Implantatlockerung häufig beobachtet wird, ist sie nur selten Grund für einen Revisionseingriff. Kommt es hingegen zum vollständigen Implantatversagen, tritt dies meist innerhalb der ersten postoperativen Wochen auf und ist revisionsbedürftig. Eine frühzeitige Abklärung durch Röntgenbildgebung sollte bei Verdacht erfolgen.