RepoMed (Medizinische Hochschule Hannover)
Not a member yet
3024 research outputs found
Sort by
In Vitro Cartilage Regeneration with a Three-Dimensional Polyglycolic Acid (PGA) Implant in a Bovine Cartilage Punch Model
No full textResorbable polyglycolic acid (PGA) chondrocyte grafts are clinically established for human articular cartilage defects. Long-term implant performance was addressed in a standardized in vitro model. PGA implants (+/− bovine chondrocytes) were placed inside cartilage rings punched out of bovine femoral trochleas (outer Ø 6 mm; inner defect Ø 2 mm) and cultured for 84 days (12 weeks). Cartilage/PGA hybrids were subsequently analyzed by histology (hematoxylin/eosin; safranin O), immunohistochemistry (aggrecan, collagens 1 and 2), protein assays, quantitative real-time polymerase chain reactions, and implant push-out force measurements. Cartilage/PGA hybrids remained vital with intact matrix until 12 weeks, limited loss of proteoglycans from “host” cartilage or cartilage–PGA interface, and progressively diminishing release of proteoglycans into the supernatant. By contrast, the collagen 2 content in cartilage and cartilage–PGA interface remained approximately constant during culture (with only little collagen 1). Both implants (+/− cells) displayed implant colonization and progressively increased aggrecan and collagen 2 mRNA, but significantly decreased push-out forces over time. Cell-loaded PGA showed significantly accelerated cell colonization and significantly extended deposition of aggrecan. Augmented chondrogenic differentiation in PGA and cartilage/PGA-interface for up to 84 days suggests initial cartilage regeneration. Due to the PGA resorbability, however, the model exhibits limitations in assessing the “lateral implant bonding”
Towards the development of a pre-vascularized attachable tissue construct: impact of chemically-induced hypoxia, growth factors and fluid dynamics on vascular tube formation in fibrin hydrogels
No full text
Potent Anti-Inflammatory Effects of Tetracyclines on Human Eosinophils
No full textEosinophils are potent pro-inflammatory cells. Not only in allergic diseases but also in other diseases there is a need for treatment strategies to induce resolution of eosinophil-mediated inflammation. During the last years beneficial non-antibiotic activities of tetracyclines (TCNs) have been shown in different diseases in which eosinophils play a role, for example, asthma and bullous pemphigoid. The working mechanism of these effects remains to be clarified. Aim of the present study was to investigate the effects of TCNs on eosinophils. Flow cytometry analysis of apoptosis, mitochondrial membrane potential, activation of caspases, intracellular H2O2 and calcium, surface expression of eosinophil activation markers was performed in highly purified peripheral blood eosinophils of non-atopic donors. Tetracycline hydrochloride, minocycline and doxycycline significantly induced eosinophil apoptosis. All TCNs were able to significantly overcome the strong survival enhancing effects of pro-eosinophilic cytokines and staphylococcus aureus enterotoxins. Tetracycline hydrochloride induced eosinophil apoptosis was accompanied by intracellular production of hydrogen peroxide, loss of mitochondrial membrane potential and activation of caspases. Moreover, tetracycline hydrochloride significantly down regulated eosinophil surface expression of CD9 and CD45, and of the activation markers CD11b and CD69, but not of CD54, CD63, or CD95. Our data, propably for the first time, point to a potent anti-inflammatory role of TCNs on eosinophils
Klinischer Vergleich der Versorgung von Ellenbogeninstabilitäten mit und ohne Internal Bracing
No full textAuswirkungen von partieller und differentieller Verifikation des Krankheitsstatus auf die Planung und Auswertung von Diagnosestudien
No full text"Der Deutsche Militärarzt 1936-1944": Psychiatrie und Psychotherapie im Spannungsfeld zwischen wissenschaftlicher Fachgesellschaft, Nationalsozialistischer Ideologie und Zweitem Weltkrieg
No full text
A Return-to-Work Intervention for Prematurely Retired Depression or Anxiety Disorder Patients.
No full textBackground: Depression and anxiety disorders are the most common cause for premature retirement of people of middle age. These people are expelled from the workforce. The following social disintegration can have an additional detrimental effect on subjects' psychological well-being which further reduces the chance to re-enter the workforce. Depression and anxiety in general need not be regarded as irreversible causes of disability. Therefore, long-term disability should be avoidable in many cases. This two-arm prospective controlled study tests a novel approach for those who have become economically inactive due to their illness with the goal to improve psychological well-being and return to work. Forty-one subjects were followed-up on over a period of 12 months and compared to 41 control cases. ANOVA for repeated measures showed that experimental subjects' psychological well-being and work ability was much better after the intervention than in the control group. These findings show that an individually tailored return-to-work intervention can be a useful therapeutic tool even after retirement