Die Biologie der Heilung der Rotatorenmanschettenläsion: Welche Rolle spielen Wachstumsfaktoren heutzutage?

Zusammenfassung: Die Rotatorenmanschettenläsion ist eine häufige Diagnose in der orthopädischen Sprechstunde. Die Rerupturrate ist trotz Weiterentwicklung der Nahtmaterialien und -techniken im offenen und arthroskopischen Bereich nach wie vor hoch. In den letzten Jahren wurden den physiologischen Vorgängen der natürlichen Insertion wie auch den biologischen Eigenschaften der Rotatorenmanschettenheilung in der Forschung vermehrt Aufmerksamkeit geschenkt. Es hat sich gezeigt, dass die Heilung der Sehnen-Knochen-Insertion der Rotatorenmanschette ein komplexes Zusammenspiel von lokalen Zellen, Stammvorläuferzellen, extrazellulärer Matrix sowie von Wachstumsfaktoren und anderen Zytokinen ist. Dementsprechend wurden verschiedene biologische In-vitro- und In-vivo-Therapieverfahren zur potenziellen Verbesserung der Reinsertion entwickelt. Ziel dieses Artikels ist es, einen Überblick über die heutige Evidenz der Augmentation der Rotatorenmanschettenrekonstruktion mit Wachstumsfaktoren zu geben. Weiterhin werden mögliche zukünftige Therapieansätze diskutier

Equine or porcine synovial fluid as a novel ex vivo model for the study of bacterial free-floating biofilms that form in human joint infections

Bacterial invasion of synovial joints, as in infectious or septic arthritis, can be difficult to treat in both veterinary and human clinical practice. Biofilms, in the form of free-floating clumps or aggregates, are involved with the pathogenesis of infectious arthritis and periprosthetic joint infection (PJI). Infection of a joint containing an orthopedic implant can additionally complicate these infections due to the presence of adherent biofilms. Because of these biofilm phenotypes, bacteria within these infected joints show increased antimicrobial tolerance even at high antibiotic concentrations. To date, animal models of PJI or infectious arthritis have been limited to small animals such as rodents or rabbits. Small animal models, however, yield limited quantities of synovial fluid making them impractical for in vitro research. Herein, we describe the use of ex vivo equine and porcine models for the study of synovial fluid induced biofilm aggregate formation and antimicrobial tolerance. We observed Staphylococcus aureus and other bacterial pathogens adapt the same biofilm aggregate phenotype with significant antimicrobial tolerance in both equine and porcine synovial fluid, analogous to human synovial fluid. We also demonstrate that enzymatic dispersal of synovial fluid aggregates restores the activity of antimicrobials. Future studies investigating the interaction of bacterial cell surface proteins with host synovial fluid proteins can be readily carried out in equine or porcine ex vivo models to identify novel drug targets for treatment of prevention of these difficult to treat infectious diseases

Query Expansion for Survey Question Retrieval in the Social Sciences

In recent years, the importance of research data and the need to archive and to share it in the scientific community have increased enormously. This introduces a whole new set of challenges for digital libraries. In the social sciences typical research data sets consist of surveys and questionnaires. In this paper we focus on the use case of social science survey question reuse and on mechanisms to support users in the query formulation for data sets. We describe and evaluate thesaurus- and co-occurrence-based approaches for query expansion to improve retrieval quality in digital libraries and research data archives. The challenge here is to translate the information need and the underlying sociological phenomena into proper queries. As we can show retrieval quality can be improved by adding related terms to the queries. In a direct comparison automatically expanded queries using extracted co-occurring terms can provide better results than queries manually reformulated by a domain expert and better results than a keyword-based BM25 baseline.Comment: to appear in Proceedings of 19th International Conference on Theory and Practice of Digital Libraries 2015 (TPDL 2015

Fixação biológica de nitrogênio em guandu (Cajanus cajan (L.) Millsp cv. BRS Mandarim) inoculada com estirpes de Bradyrhizobium spp. na presença ou ausência de tratamento com fungicida.

A avaliação da eficiência da fixação biológica de nitrogênio é um processo prioritário durante o melhoramento genético para obtenção de novas cultivares de leguminosas. A cultivar de guandu Mandarim foi desenvolvida para uso como recurso forrageiro e também para a rotação de culturas com a cana-de-açúcar. Destaca-se pela alta produtividade de forragem, retenção de folhas no inverno e baixo teor de taninos. Os experimentos foram conduzidos em casa-de-vegetação na Embrapa Pecuária Sudeste com o objetivo de avaliar a fixação biológica de N do guandu cv. Mandarim inoculada com três estirpes de Bradyrhizobium spp. (SEMIA 6156, SEMIA 6157 e um isolado) na presença ou ausência de tratamento de sementes com fungicida. As variáveis analisadas foram: número e massa seca de nódulos, massa seca da raiz, massa seca da parte aérea, teor de N nas folhas e relação colmo:folha de plantas. Concluiu-se que as plantas que tiveram as sementes inoculadas apresentaram boa nodulação e fixação biológica de nitrogênio em relação às não inoculadas, não houve diferença entre as estirpes. O tratamento das sementes com o fungicida captan não afetou a nodulação e teor de N na maioria das combinações

Accepting higher morbidity in exchange for sacrificing fewer animals in studies developing novel infection-control strategies.

Preventing bacterial infections from becoming the leading cause of death by the year 2050 requires the development of novel, infection-control strategies, building heavily on biomaterials science, including nanotechnology. Pre-clinical (animal) studies are indispensable for this development. Often, animal infection outcomes bear little relation to human clinical outcome. Here, we review conclusions from pathogen-inoculum dose-finding pilot studies for evaluation of novel infection-control strategies in murine models. Pathogen-inoculum doses are generally preferred that produce the largest differences in quantitative infection outcome parameters between a control and an experimental group, without death or termination of animals due to having reached an inhumane end-point during the study. However, animal death may represent a better end-point for evaluation than large differences in outcome parameters or number of days over which infection persists. The clinical relevance of lower pre-clinical outcomes, such as bioluminescence, colony forming units (CFUs) retrieved or more rapid clearance of infection is unknown, as most animals cure infection without intervention, depending on pathogen-species and pathogen-inoculum dose administered. In human clinical practice, patients suffering from infection present to hospital emergency wards, frequently in life-threatening conditions. Animal infection-models should therefore use prevention of death and recurrence of infection as primary efficacy targets to be addressed by novel strategies. To compensate for increased animal morbidity and mortality, animal experiments should solely be conducted for pre-clinical proof of principle and safety. With the advent of sophisticated in vitro models, we advocate limiting use of animal models when exploring pathogenesis or infection mechanisms