Verletzungen und Überlastungsschäden im Motorrad-Enduro-Sport

According to public opinion, enduro- motorcycling is a dangerous sports. Little is known of accident mechanism during a competition and overuse injuries in enduro- motorcycling. Aim of this study is to evaluate accident and injury patterns as well as overuse syndromes.To detect overuse injuries volunteering athletes were examined immediately before and after each run. Six percent of all started riders sustained an accident. Two percent got injured of which 80% were of superficial kind. More then 50% of all examined riders presented overuse injuries with predominance at the forearm, the wrist and the hand. The transient carpal tunnel syndrome and the beginning compartment syndrome of the forearm flexors were established as diagnosis. Coolpacks and simple vibration blockers led to subjective improvement. Competitive enduro- motorcycling is an average risky sports. The incidence of overuse reactions is evident in more of 50% of all riders and is hence a relevant issue in sports medicine.     

Chemokine expression in the white matter spinal cord precursor niche after force‐defined spinal cord contusion injuries in adult rats

Inflammatory cascades induced by spinal cord injuries (SCI) are localized in the white matter, a recognized neural stem‐ and progenitor‐cell (NSPC) niche of the adult spinal cord. Chemokines, as integrators of these processes, might also be important determinants of this NSPC niche. CCL3/CCR1, CCL2/CCR2, and SDF‐1α/CXCR4 were analyzed in the ventrolateral white matter after force defined thoracic SCI: Immunoreactivity (IR) density levels were measured 2 d, 7 d, 14 d, and 42 d on cervical (C 5), thoracic (T 5), and lumbar (L 5) levels. On day post operation (DPO) 42, chemokine inductions were further evaluated by real‐time RT‐PCR and Western blot analyses. Cellular phenotypes were confirmed by double labeling with markers for major cell types and NSPCs (nestin, Musashi‐1, NG2, 3CB2, BLBP). Mitotic profiles were investigated in parallel by BrdU labeling. After lesion, chemokines were induced in the ventrolateral white matter on IR‐, mRNA‐, and protein‐level. IR was generally more pronounced after severe lesions, with soaring increases of CCL2/CCR2 and continuous elevations of CCL3/CCR1. SDF‐1α and CXCR4 IR induction was focused on thoracic levels. Chemokines/‐receptors were co‐expressed with astroglial, oligodendroglial markers, nestin, 3CB2 and BLBP by cells morphologically resembling radial glia on DPO 7 to DPO 42, and NG2 or Musashi‐1 on DPO 2 and 7. In the white matter BrdU positive cells were significantly elevated after lesion compared with sham controls on all investigated time points peaking in the early time course on thoracic level: Here, chemokines were co‐expressed by subsets of BrdU‐labeled cells. These findings suggest an important role of chemokines/‐receptors in the subpial white matter NSPC niche after SCI. © 2010 Wiley‐Liss, Inc.     

From the Cover: Rice yields in tropical/subtropical Asia exhibit large but opposing sensitivities to minimum and maximum temperatures

Data from farmer-managed fields have not been used previously to disentangle the impacts of daily minimum and maximum temperatures and solar radiation on rice yields in tropical/subtropical Asia. We used a multiple regression model to analyze data from 227 intensively managed irrigated rice farms in six important rice-producing countries. The farm-level detail, observed over multiple growing seasons, enabled us to construct farm-specific weather variables, control for unobserved factors that either were unique to each farm but did not vary over time or were common to all farms at a given site but varied by season and year, and obtain more precise estimates by including farm- and site-specific economic variables. Temperature and radiation had statistically significant impacts during both the vegetative and ripening phases of the rice plant. Higher minimum temperature reduced yield, whereas higher maximum temperature raised it; radiation impact varied by growth phase. Combined, these effects imply that yield at most sites would have grown more rapidly during the high-yielding season but less rapidly during the low-yielding season if observed temperature and radiation trends at the end of the 20th century had not occurred, with temperature trends being more influential. Looking ahead, they imply a net negative impact on yield from moderate warming in coming decades. Beyond that, the impact would likely become more negative, because prior research indicates that the impact of maximum temperature becomes negative at higher levels. Diurnal temperature variation must be considered when investigating the impacts of climate change on irrigated rice in Asia.     

Multidetector-row computed tomography and magnetic resonance imaging of atherosclerotic lesions in human ex vivo coronary arteries

In the present study, we tested the ability of multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI) to identify and retrospectively characterize atherosclerotic lesions in human ex vivo coronary arteries. Thirteen ex vivo hearts were studied with MDCT and MRI. MDCT-images were obtained with an isotropic voxel size of 0.6mm(3). MR images were obtained with an in-plane resolution of 195 microm and 3mm slice thickness. All images were matched with histopathology sections. For both modalities, the sensitivity for the detection of any atherosclerotic lesion was evaluated, and a retrospective analysis of plaque morphology according to criteria defined by the American Heart Association (AHA) was performed. At histopathology, 28 atherosclerotic lesions were found. 21 and 23 of these lesions were identified by MDCT and MRI, respectively. Both modalities detected a small number of false-positive lesions. After retrospective matching with histopathology, MDCT as well as MRI were able to differentiate typical morpholocigal features for fatty, fibrous or calcified plaque components. Using the information presented in this study, in vivo coronary artery wall imaging using MDCT as well as MRI could be facilitated and supported for future investigations on this subject.     

Hydrogen peroxide contrast echocardiography

Several agents are used as echocardiographic contrast agents, but their unreliability discourages routine clinical use. Studies from the early 1960s suggest that dilute hydrogen peroxide (H₂O₂) is a safe intravascular agent. Its use was evaluated in contrast echocardiography. To obtain dense opacification reliably, H₂O₂ (3%) was passed through a sterile 0.2 μ Millipore filter and diluted with heparinized saline solution to make a 0.1 to 0.2% solution. A drop of blood was withdrawn from an indwelling peripheral venous needle into a syringe containing 0.5 to 2.0 ml of the dilute H₂O₂ and the contents injected. Studies in dogs, normal adults and 36 patients with noncyanotic congenital and acquired cardiac disorders produced dense opacification with no complications. In vitro mixture of H₂O₂ (0.3%) with leukocyte-poor blood or plasma produced only a few microbubbles, while addition to whole blood or buffy coat produced many, suggesting a role for leukocyte peroxidase. H₂O₂ contrast echocardiography is simple, inexpensive, and reliably provides dense, sustained opacification. This study and previous studies suggest that intravenous injection of 0.2% H₂O₂ can be done safely. Great caution should be exercised in patients with severe pulmonary hypertension or large right-to-left shunts because little clinical experience with H₂O₂ is available.     

Right ventricular pacing is an independent predictor for ventricular tachycardia/ventricular fibrillation occurrence and heart failure events in patients with an implantable cardioverter-defibrillator

Aims: There is increasing evidence that right ventricular (RV) pacingmay have detrimental effects by increasing morbidity and mortalityfor heart failure in implantable cardioverter–defibrillator(ICD) patients. In this study we prospectively tested the hypothesisthat cumulative RV pacing increases ventricular tachycardia/ventricularfibrillation (VT/VF) occurrence (primary endpoint) and hospitalizationand mortality for heart failure (secondary endpoint) in a predominantlysecondary prophylactic ICD patient population. Methods and results: Two hundred and fifty patients were divided into two groupsaccording to the median of cumulative RV pacing (2 vs. >2%)and prospectively followed-up for occurrence of primary andsecondary endpoints for 18 ± 4 months. Established predictorsfor VT/VF occurrence and heart failure events such as age, leftventricular ejection fraction (EF), QRS duration, history ofatrial fibrillation, and NT-proBNP were collected at enrolment.Multivariate Cox regression analysis revealed that cumulativeRV pacing > 2% and EF < 40% were independent predictorsfor VT/VF occurrence and heart failure events. Kaplan–Meieranalysis showed that patients with >2% cumulative RV pacingmore frequently suffered from VT/VF occurrence and heart failurehospitalization. Conclusion: Cumulative RV pacing > 2% and EF < 40% are independentpredictors for VT/VF occurrence and mortality and hospitalizationfor heart failure in predominantly secondary prophylactic ICDpatients. Our data show that algorithms capable of reducingcumulative RV pacing should be used more frequently in clinicalpractice.