Gene-therapeutic approach for the expression of heterologous receptors in the heart

Vorliegende Arbeit untersucht die Grundlagen und die Durchführbarkeit für einen neuen, möglichen Ansatz zur Therapie der Herzinsuffizienz auf molekularer Ebene. Hierzu wurde der im Herzen heterologe, G-Protein-gekoppelte, PTH/PTHrP1-Rezeptor in Kardiomyoblasten und Kardiomyozyten zur Expression gebracht. Da in der Herzinsuffizienz im Myokard dehnungsabhängig PTHrP ausgeschüttet wird, könnte so über die Expression des heterologen Rezeptors und cAMP-Bildung über das Gs-Adenylatzyklase-System ein parakriner Loop geschlossen und damit eine Steigerung der Kontraktilität rezeptorbesetzter Zellen, d.h. ein positiv inotroper Effekt erreicht werden. Als Gen-Vektoren untersuchten wir zum einen Adenoviren, zum anderen Adeno-assoziierte Viren, die beide mittels Markergenen auf ihre Effektivität, Fremd-DNA in Herzzellen einzuschleusen, getestet wurden. Alle Virus-Proplasmide, in die das Gen für den PTH/PTHrP1-Rezeptor einkloniert worden war, wurden funktionell gemessen. Die Arbeit zeigt, daß es prinzipiell möglich ist, fremde Gene, insbesondere das Gen für den PTH/PTHrP1-Rezeptor, mit guter Effizienz sowohl in vitro in Kardiomyoblasten und in isolierten Kardiomyozyten als auch in vivo im Myokard zur Expression zu bringen. Alle Gene behielten nach Umklonierung und heterologer Expression in den verschiedenen Zellen ihre Funktion.The present study investigates the feasibility of a novel, molecular approach to therapy congestive heart failure. For this, we overexpressed the heterologous, G-Protein-coupled, PTH/PTHrP1-Receptor in cardiomyoblasts and cardiomyocytes. Because PTHrP is released in a stretch-responsive manner from the myocard in congestive heart failure, overexpression of the heterologous receptor and cAMP formation via the Gs/adenylyl cyclase system could result in a positive inotropic paracrine loop through an increased contractility of PTH/PTHrP1-expressing cells. As gene-vectors we investigated on the one hand adenoviruses, on the other hand adeno-associated viruses. Both were tested with reportergenes for their ability to transfer foreign DNA into heartcells. All virus-proplasmides, encoding the PTH/PTHrP1-receptor, were functionally tested. The investigations show, that it is possible to express with a good efficiency heterologous genes, especially the PTH/PTHrP1-gene, as well in vitro in cardiomyoblasts and in cardiomyocytes as in vivo in the myocard. All genes maintained after cloning and heterologous expression in the different cells their function

Terminology and Classification of Muscle Injuries in Sport: The Munich Consensus Statement

Objective: To provide a clear terminology and classification of muscle injuries in order to facilitate effective communication among medical practitioners and development of systematic treatment strategies. Methods: Thirty native English-speaking scientists and team doctors of national and first division professional sports teams were asked to complete a questionnaire on muscle injuries to evaluate the currently used terminology of athletic muscle injury. In addition, a consensus meeting of international sports medicine experts was established to develop practical and scientific definitions of muscle injuries as well as a new and comprehensive classification system. Results: The response rate of the survey was 63%. The responses confirmed the marked variability in the use of the terminology relating to muscle injury, with the most obvious inconsistencies for the term strain. In the consensus meeting, practical and systematic terms were defined and established. In addition, a new comprehensive classification system was developed, which differentiates between four types: functional muscle disorders (type 1: overexertion-related and type 2: neuromuscular muscle disorders) describing disorders without macroscopic evidence of fibre tear and structural muscle injuries (type 3: partial tears and type 4: (sub)total tears/tendinous avulsions) with macroscopic evidence of fibre tear, that is, structural damage. Subclassifications are presented for each type. Conclusions: A consistent English terminology as well as a comprehensive classification system for athletic muscle injuries which is proven in the daily practice are presented. This will help to improve clarity of communication for diagnostic and therapeutic purposes and can serve as the basis for future comparative studies to address the continued lack of systematic information on muscle injuries in the literature. What are the new things: Consensus definitions of the terminology which is used in the field of muscle injuries as well as a new comprehensive classification system which clearly defines types of athletic muscle injuries

Suture anchor repair of proximal rectus femoris avulsions in elite football players.

To report the results of suture anchor repair of proximal rectus femoris avulsions in elite football players.Four professional football players (first-team regulars of European first division football clubs) underwent suture anchor repair of complete proximal rectus femoris avulsions with significant tendon retraction. The following parameters were analysed: demographic data, mechanism of injury, type of injury, classification according to the Munich consensus statement, time between injury and surgery, time between surgery and full participation in training and availability for match and/or competition selection (return to play/RTP), and time between surgery and the comeback to the first official league match (return to competition/RTC). Radiographic evaluation was performed by magnetic resonance imaging (MRI) obtained pre-operatively and at 6 and 12 weeks post-operatively. All players were followed for at least 24 months after return to play to exclude recurrence.Mean age at surgery was 30 ± 2 years. All injuries occurred while kicking a ball, with the dominant leg affected in all patients. The injury was considered acute in three cases and chronic in one case. According to the Munich classification, all injures were type 4. Mean time to surgery was 60 ± 88 days (range, 8-191), mean time to RTP was 111 ± 15 days (range, 100-134), and mean time to RTC was 140 ± 23 days (range, 114-166). Follow-up MRIs demonstrated anatomically reinserted tendons with decreasing signal intensity over time in all cases. After a mean follow-up of 35 ± 6 months, all players were still competing at the same level as before the injury without re-injury.Suture anchor repair of proximal rectus femoris avulsions allows unrestricted return to play in professional elite football players. Return to play can be expected at approximately 16 weeks post-operatively