Einfluss der Matrix-Metalloproteinase-9 (MMP-9) auf das Metastasierungsverhalten von Oropharynxkarzinomen

Der MMP-9 Expressionslevel ist immunhistochemisch untersucht worden bei 105 Patienten (40-79 Jahre, Mittelwert: 57.84 Jahre), die an Oropharynxkarzinomen litten. (22x T1, 31x T2, 24x T3, 28xT4) und verschiedene Halslymphknotenstadien hatten (41x N0, 6x N1, 54x N2, 4x N3) Ergebnisse: Es bestant eine signifikante Korrelation zwischen dem Expressionslevel für MMP-9 und dem T-Stadium (p<0.05) und dem N-Stadium (p<0.01) und dem UICC-Stadium (p<0.01). Am beeindruckensten sicherlich die hohe MMP-9 Expression und dem hohen UICC-Stadium. Ergebniss: Die Ergebnisse geben weitere Hinweise, dass MMP-9 eine große Rolle im Metastasierungsverhalten von Kopf- und Halskarzinomen zukommt. Es wird in Zukunft nötig sein, eine standadisierte Färbeeinteilung zu kreieren für valide Ergebnisse

Towards the statistical analysis and visualization of places (Short Paper)

The concept of place recently gains momentum in GIScience. In some fields like human geography, spatial cognition or information theory, this topic already has a longer scholarly tradition. This is however not yet completely the case with statistical spatial analysis and cartography. Despite that, taking full advantage of the plethora of user-generated information that we have available these days requires mature place-based statistical and visualization concepts. This paper contributes to these developments: We integrate existing place definitions into an understanding of places as a system of interlinked, constituent characteristics. Based on this, challenges and first promising conceptual ideas are discussed from statistical and visualization viewpoints

Impact of Dental Implant Surface Modifications on Osseointegration

Objective. The aim of this paper is to review different surface modifications of dental implants and their effect on osseointegration. Common marketed as well as experimental surface modifications are discussed. Discussion. The major challenge for contemporary dental implantologists is to provide oral rehabilitation to patients with healthy bone conditions asking for rapid loading protocols or to patients with quantitatively or qualitatively compromised bone. These charging conditions require advances in implant surface design. The elucidation of bone healing physiology has driven investigators to engineer implant surfaces that closely mimic natural bone characteristics. This paper provides a comprehensive overview of surface modifications that beneficially alter the topography, hydrophilicity, and outer coating of dental implants in order to enhance osseointegration in healthy as well as in compromised bone. In the first part, this paper discusses dental implants that have been successfully used for a number of years focusing on sandblasting, acid-etching, and hydrophilic surface textures. Hereafter, new techniques like Discrete Crystalline Deposition, laser ablation, and surface coatings with proteins, drugs, or growth factors are presented. Conclusion. Major advancements have been made in developing novel surfaces of dental implants. These innovations set the stage for rehabilitating patients with high success and predictable survival rates even in challenging conditions

Increased Postoperative Bleeding Risk among Patients with Local Flap Surgery under Continued Clopidogrel Therapy

Purpose. The purpose of the study was to evaluate the influence of a continued antiplatelet therapy with clopidogrel on postoperative bleeding risk in patients undergoing skin tumor resection and reconstruction with local flaps or skin grafts under outpatient conditions. Patients and Methods. The authors designed and implemented a retrospective clinical cohort study at the General Hospital Balingen. The primary endpoint was the bleeding ratio in patients with clopidogrel treatment in comparison to patients without any anticoagulant or antiplatelet therapy. Wound healing was evaluated on days 1, 3, 5, 7, 10, and 14. Results. 650 procedures were performed, 123 of them under continued clopidogrel therapy. There were significantly more postoperative bleeding complications among patients with continued antiplatelet therapy. Regarding the whole study population, malignant lesions, a larger defect size, and skin grafts were accompanied by a higher rate of bleeding incidents. However, there were no significant findings in the univariate analysis of the clopidogrel group. All bleeding incidents were easily manageable. Conclusion. Despite an increased bleeding ratio among patients under continued clopidogrel therapy, the performance of simple surgical procedures can be recommended. However, cautious preparation and careful hemostasis are indispensable

Selective Bacterial Targeting and Infection-Triggered Release of Antibiotic Colistin Conjugates.

In order to render potent, but toxic antibiotics more selective, we have explored a novel conjugation strategy that includes drug accumulation followed by infection-triggered release of the drug. Bacterial targeting was achieved using a modified fragment of the human antimicrobial peptide ubiquicidin, as demonstrated by fluorophore-tagged variants. To limit the release of the effector colistin only to infection-related situations, we introduced a linker that was cleaved by neutrophil elastase (NE), an enzyme secreted by neutrophil granulocytes at infection sites. The linker carried an optimized sequence of amino acids that was required to assure sufficient cleavage efficiency. The antibacterial activity of five regioisomeric conjugates prepared by total synthesis was masked, but was released upon exposure to recombinant NE when the linker was attached to amino acids at the 1- or the 3-position of colistin. A proof-of-concept was achieved in co-cultures of primary human neutrophils and Escherichia coli that induced the secretion of NE, the release of free colistin, and an antibacterial efficacy that was equal to that of free colistin

Clinical Study Postoperative Bleeding Risk for Oral Surgery under Continued Clopidogrel Antiplatelet Therapy

Object. To determine the incidence of postoperative bleeding for oral osteotomy carried out under continued monoantiplatelet therapy with clopidogrel and dual therapy with clopidogrel/aspirin. Design. Retrospective single center observatory study of two study groups and a control group. Methods. A total of 64 and 60 oral osteotomy procedures carried out under continued monoclopidogrel therapy and dual clopidogrel/aspirin therapy, respectively, were followed for two weeks for postoperative bleeding. Another 281 similar procedures were also followed as a control group. All oral osteotomy procedures were carried out on an outpatient basis. Results. We observed postoperative bleeding in 2/281 (0.7%) cases in the control group, in 1/64 (1.6%) cases in the clopidogrel group, and in 2/60 (3.3%) cases in the dual clopidogrel/aspirin group. The corresponding 95% confidence intervals are 0-1.7%, 0-4.7%, and 0-7.8%, respectively, and the incidences did not differ significantly among the three groups ( &gt; 0.09). Postoperative hemorrhage was treated successfully in all cases with local measures. No changes of antiplatelet medication, transfusion, nor hospitalisation were necessary. No major cardiovascular events were recorded. Conclusions. Our results indicate that minor oral surgery can be performed safely under continued monoantiplatelet medication with clopidogrel or dual antiplatelet medication with clopidogrel/aspirin

Accuracy of Bone Measurements in the Vicinity of Titanium Implants in CBCT Data Sets: A Comparison of Radiological and Histological Findings in Minipigs

Purpose. The aim of this animal study was the determination of accuracy of bone measurements in CBCT (cone-beam computed tomography) in close proximity to titanium implants. Material and Methods. Titanium implants were inserted in eight Göttingen minipigs. 60 implants were evaluated histologically in ground section specimen and radiologically in CBCT in regard to thickness of the buccal bone. With random intercept models, the difference of histologic measurements and CBCT measurements of bone thickness was calculated. Results. The mean histological thickness of the buccal bone was 5.09 mm (CI 4.11–6.08 mm). The four raters measured slightly less bone in CBCT than it was found in histology. The random effect was not significant (p value 1.000). Therefore, the Intraclass Correlation Coefficient (ICC) was 98.65% (CI 100.00–96.99%). Conclusion. CBCT is an accurate technique to measure even thin bone structures in the vicinity of titanium implants