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The effect of plyometric training on [Ca.sup.2} sensitivity and the influence of troponin T (TnT) isoforms on [Ca.sup.2} activation properties in skinned human muscle fibers are studied. Results found a significant improvement after training for static jump, countermovement jump, 6x5-m shuttle-run test, and leg-press performances.

Gross mechanical efficiency (ME) at different power output (PO) levels of synchronous hand cycling is presented. The influence of increasing PO by changing crank rate or resistance in wheelchair users with experience in hand cycling is also evaluated.

The responses of mRNA for insulin like growth factor-I (IGF-I) and insulin like growth factor-II (IGF-II) and the phosphorylation state of components of anabolic signaling pathways p70(super s6k) and eukaryotic initiation factor-4e binding protein-I was tested to a bout of high-intensity resistance exercise after 5 d of creatine supplementation. The increase in lean body mass often reported after creatine supplementation could be mediated by signaling pathways involving IGF and 4E-BP.

BackgroundIn randomised controlled trials (RCTs) of interventions that aim to prevent sports injuries, the intention-to-treat principle is a recommended analysis method and one emphasised in the Consolidated Standards of Reporting Trials (CONSORT) statement that guides quality reporting of such trials. However, an important element of injury prevention trials—compliance with the intervention—is not always well-reported. The purpose of the present educational review was to describe the compliance during follow-up in eight large-scale sports injury trials and address compliance issues that surfaced. Then, we discuss how readers and researchers might consider interpreting results from intention-to-treat analyses depending on the observed compliance with the intervention.MethodsData from seven different randomised trials and one experimental study were included in the present educational review. In the trials that used training programme as an intervention, we defined full compliance as having completed the programme within ±10% of the prescribed running distance (ProjectRun21 (PR21), RUNCLEVER, Start 2 Run) or time-spent-running in minutes (Groningen Novice Running (GRONORUN)) for each planned training session. In the trials using running shoes as the intervention, full compliance was defined as wearing the prescribed running shoe in all running sessions the participants completed during follow-up.ResultsIn the trials that used a running programme intervention, the number of participants who had been fully compliant was 0 of 839 (0%) at 24-week follow-up in RUNCLEVER, 0 of 612 (0%) at 14-week follow-up in PR21, 12 of 56 (21%) at 4-week follow-up in Start 2 Run and 8 of 532 (1%) at 8-week follow-up in GRONORUN. In the trials using a shoe-related intervention, the numbers of participants who had been fully compliant at the end of follow-up were 207 of 304 (68%) in the 21 week trial, and 322 of 423 (76%), 521 of 577 (90%), 753 of 874 (86%) after 24-week follow-up in the other three trials, respectively.ConclusionThe proportion of runners compliant at the end of follow-up ranged from 0% to 21% in the trials using running programme as intervention and from 68% to 90% in the trials using running shoes as intervention. We encourage sports injury researchers to carefully assess and report the compliance with intervention in their articles, use appropriate analytical approaches and take compliance into account when drawing study conclusions. In studies with low compliance, G-estimation may be a useful analytical tool provided certain assumptions are met.

BackgroundTime-to-event modelling is underutilised in sports injury research. Still, sports injury researchers have been encouraged to consider time-to-event analyses as a powerful alternative to other statistical methods. Therefore, it is important to shed light on statistical approaches suitable for analysing training load related key-questions within the sports injury domain.ContentIn the present article, we illuminate: (i) the possibilities of including time-varying outcomesin time-to-event analyses, (ii) how to deal with a situation where different types of sports injuries are included in the analyses (ie, competing risks), and (iii) how to deal with the situation where multiple subsequent injuries occur in the same athlete.ConclusionTime-to-event analyses can handle time-varying outcomes, competing risk and multiple subsequent injuries. Although powerful, time-to-event has important requirements: researchers are encouraged to carefully consider priorto any data collection that five injuries per exposure state or transition is needed to avoid conducting statistical analyses on time-to-event data leading to biased results. This requirement becomes particularly difficult to accommodate when a stratified analysis is required as the number of variables increases exponentially for each additional strata included. In future sports injury research, we need stratified analyses if the target of our research is to respond to the question: ‘how much change in training load is too much before injury is sustained, among athletes with different characteristics?’ Responding to this question using multiple time-varying exposures (and outcomes) requires millions of injuries. This should not be a barrier for future research, but collaborations across borders to collecting the amount of data needed seems to be an important step forward.

Background‘How much change in training load is too much before injury is sustained, among different athletes?’is a key question in sports medicine and sports science. To address this question the investigator/practitioner must analyse exposure variables that change over time, such as change in training load. Very few studies have included time-varying exposures (eg, training load) and time-varying effect-measure modifiers (eg, previous injury, biomechanics, sleep/stress) when studying sports injury aetiology.AimTo discuss advanced statistical methods suitable for the complex analysis of time-varying exposures such as changes in training load and injury-related outcomes.ContentTime-varying exposures and time-varying effect-measure modifiers can be used in time-to-event models to investigate sport injury aetiology. We address four key-questions (i) Does time-to-event modelling allow change in training load to be included as a time-varying exposure for sport injury development? (ii) Why is time-to-event analysis superior to other analytical concepts when analysing training-load related data that changes status over time? (iii) How can researchers include change in training load in a time-to-event analysis? and, (iv) Are researchers able to include other time-varying variables into time-to-event analyses? We emphasise that cleaning datasets, setting up the data, performing analyses with time-varying variables and interpreting the results is time-consuming, and requires dedication. It may need you to ask for assistance from methodological peers as the analytical approaches presented this paper require specialist knowledge and well-honed statistical skills.ConclusionTo increase knowledge about the association between changes in training load and injury, we encourage sports injury researchers to collaborate with statisticians and/or methodological epidemiologists to carefully consider applying time-to-event models to prospective sports injury data. This will ensure appropriate interpretation of time-to-event data.

The purpose of this study was to evaluate the role of diffusion-weighted MR imaging (DW-MRI) in the assessment of treatment response of primary or secondary liver malignancies after stereotactic radiosurgery (SRS) using robotic radiosurgery. All patients who underwent SRS therapy for hepatic malignancies who had pre- and post-interventional MR examinations including DW-MRI at our hospital between 02/2010 and 02/2012 were included. A retrospective analysis of the institutional imaging database identified 13 patients (4 men, 9 women, mean age: 66 years) with a total of 14 primary or secondary liver malignancies. Criteria of tumor response to treatment were a decrease in size and/or loss of contrast enhancement as assessed with respect to RECIST criteria. Mean apparent diffusion coefficient (ADC) values for normal liver parenchyma and hepatic masses in each MR examination were calculated and compared using two-tailed, paired t-test with a significance level of 0.05. Mean ADC values of liver malignancies were 1.10 ± 0.30 x 10-3mm2/s, 1.48 ± 0.35 x 10-3mm2/sand 1.56 ± 0.40 x 10-3mm2/son pre-interventional, the first post-interventional, and the second post-interventional DW-MRI. There was a significant increase of ADC values between the pre-interventional examination and the first and second post-interventional follow-up exams (p< 0.01 and p= 0.01, respectively). However, there was no statistical difference between the ADC values of the first and second post-interventional MRI. ADC values of normal liver parenchyma did not show significant changes in ADC values during pre- and post-interventional MRI. ADC measurements may allow the evaluation of response to treatment of hepatic malignancies by SRS. ADC values of liver malignancies increase significantly after SRS treatment.

The aim of this study was to assess the diagnostic performance of a dynamic, multiphasic contrast-enhanced volume-interpolated sequence with advanced parallel imaging techniques, Dixon fat saturation, and view sharing with 5 hepatic arterial subphases for the detection of focal liver lesions.

Genetic predisposition to life-threatening cardiac arrhythmias such as congenital long-QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) represent treatable causes of sudden cardiac death in young adults and children. Recently, mutations in calmodulin (CALM1, CALM2) have been associated with severe forms of LQTS and CPVT, with life-threatening arrhythmias occurring very early in life. Additional mutation-positive cases are needed to discern genotype–phenotype correlations associated with calmodulin mutations.

The aim of this study was to evaluate free-breathing single-shot real-time cine imaging for functional cardiac imaging at 3 T with increased spatial resolution. Special emphasis of this study was placed on the influence of parallel imaging techniques.

The aim of this study was to assess and delineate chronic myocardial infarction (CMI) using precontrast and postcontrast T1 mapping techniques including quantification of extracellular volume fractions (ECVs).

To determine the accuracy of computed tomography (CT) dynamic stress myocardial perfusion imaging to estimate myocardial blood flow (MBF) in a porcine animal model with variable degrees of induced coronary artery stenosis in comparison with microsphere-derived MBF.

Short-term storage trials were conducted with semen of Atlantic sturgeon Acipenser oxyrinchuscollected from a total of nine wild males during the 2008 and 2009 spawning seasons on the Hudson River. Semen samples were kept refrigerated (4 ± 1°C) and stored in different gaseous atmospheres and storage extenders. The gaseous environments included oxygen, nitrogen, and air, while the extender treatments included modified Tsvetkova (MT), Park and Chapman (PC), and undiluted. Analyses of four response variables—percent viable sperm (viability), percent motile sperm (motility), curvilinear velocity (VCL), and ATP content—were determined on the day of arrival in the laboratory and then every other day for 7 d in 2008 and 21 d in 2009. The experiments were conducted in a split-split-plot design to examine dilution treatment, gas atmosphere, and repeated measures across days, and linear analyses of covariance models were fit to the data after appropriate transformation. Storage of sperm in an oxygen atmosphere was superior to storage in a nitrogen atmosphere for all variables. Storage of semen in 100% or 21% (air) oxygen in PC did not lead to differences among variables except for viability; viability was maintained at more than 95% through 13 d, decreasing to 88% and 94% on day 21 in 100% oxygen and air, respectively. During the last 5 d survival in an air atmosphere was better than that in 100% oxygen. Motility decreased during the 21 d of storage and the decline was greater in undiluted than in PC-extended semen, decreasing from 85% on day 1 to approximately 21% and 47%, respectively, on day 21. We conclude that for Atlantic sturgeon semen storage, PC is the extender of choice and semen viability can be maintained for up to 21 d with some expectation of successful fertilization.

To implement and evaluate the accuracy of unsupervised fully automated inline analysis of global ventricular function and myocardial mass (MM). To compare automated with manual segmentation in patients with cardiac disorders.

Market-sized 2-year-old striped bass Morone saxatilis(average weight, 645 g) were evaluated in three different concentrations of Aqui-S at one of three different temperatures. Time to stage 4 of anesthesia, recovery time, and plasma cortisol level as an indicator of acute stress response, were determined. We found a significant difference in the time to stage 4 between 25 mg/L and 35 or 45 mg/L. This difference was present at all three temperatures tested. There were also significant differences in recovery time and blood cortisol level, but these differences were not consistent across all temperatures. There was a significant interaction between temperature and dose when analyzing cortisol levels. For the range of concentrations evaluated, we recommend an Aqui-S dose of 35 mg/L when anesthetizing market-sized striped bass.

To implement parallel imaging algorithms in fast gradient recalled echo sequences for myocardial perfusion imaging and evaluate image quality, signal-to-noise ratio (SNR), contrast-enhancement ratio (CER), and semiquantitative perfusion parameters.

To implement myocardial first-pass perfusion imaging at 3 Tesla and to evaluate the potential benefit with regard to signal parameters in comparison to 1.5 Tesla using identical sequence settings and an intraindividual comparison.

Le manque de préparation physique, la charge d’entraînement ou la fatigue pourraient avoir un impact sur le nombre de blessures sportives observées au cours de la saison sportive. Le but de cette étude était d’analyser la répartition des lésions du ligament croisé antérieur (LCA) au cours de la saison dans les sports à pivot chez des non-professionnels. L’hypothèse était que la répartition n’était pas uniforme au cours de la saison.

Le rôle des lésions de la rampe du ménisque médial (MM) et de la racine postérieure du ménisque latéral (ML) dans la laxité rotatoire dynamique du genou après lésion du ligament croisé antérieur (LCA) a récemment été démontré. La prévalence de ces lésions n’est toutefois pas connue. Le but était d’analyser le type de lésions méniscales observées dans une série de reconstruction du LCA. L’hypothèse était qu’un nombre important de patients présentaient une lésion de la rampe ou de la racine.

BackgroundSo far, only few biomechanical studies have specifically addressed the acute effect of the heel-to-toe drop in running shoes, but longitudinal studies are lacking.ObjectiveOur aim was to investigate if the drop of conventional cushioned shoes induces specific long-term adaptations in running technique.DesignRandomised controlled trial.SettingLeisure-time distance runners were tested on a treadmill at their preferred running speed before and after a 6-month period.ParticipantsStudy participants (n=59), unexperienced with minimalist shoes, were recruited via advertisements in local newspapers.InterventionThe participants received a pair of running shoes with a drop of 10 mm (D10, n=20), 6 mm (D6, n=17) or 0 mm (D0, n=22). Apart from the shoe drop, the 3 versions were strictly identical.Main Outcome MeasurementsKinematic and spatio-temporal variables of running trials were obtained using synchronized systems for three-dimensional motion analysis (200 Hz) and step cycle event detection. Joint angles were investigated at initial contact and mid-stance phase of 151±22 analysed steps per record. Two-way analysis of variance for repeated measures with the post hoc Bonferroni correction was used and accepted significance was set at p<0.05.ResultsThe participants performed on average a total of 332±178 km over 163±16 days between pre- and post-tests. No interaction between shoe drop and time was found for any of the spatio-temporal variables, or for any angles at initial contact. At mid-stance phase, a significant shoe drop by time interaction was found for knee abduction angle (p=0.032). For D0 group, knee abduction decreased (−0.3±3.1 vs. -1.3±2.6°) in contrast to D6 (0.3±2.7 vs. 1.3±3.1°) and D10 (−0.2±3.2 vs. 0.5±3.1°) groups. However, none of the pairwise comparisons was significant in the post-hoc analysis.ConclusionsShoe drop of standard cushioned shoes does not seem to influence long term adaptation in running biomechanics.

Au cours du suivi d’un patient opéré d’une plastie du LCA, le genou controlatéral sain sert de référence pour déterminer la laxité différentielle. Sa variabilité lors d’un suivi longitudinal n’a pas encore été déterminée. Le but de cette étude est de déterminer la différence minimale cliniquement pertinente du GNRB®par l’analyse du genou sain dans un suivi longitudinal postopératoire du genou opposé.

Les lésions de la rampe du ménisque médial sont observées chez 15–24 % des patients nécessitant une reconstruction du ligament croisé antérieur (LCA). Leur influence sur la laxité du genou n’a pas encore été rapportée in vivo. Le but de cette étude est de déterminer si la présence d’une lésion de la rampe du ménisque médial lors de la reconstruction du LCA est associée à un plus haut degré de laxité aux tests préopératoires de Lachman et de ressaut.

La laxité du genou reste peu étudiée dans les lésions de la rampe du ménisque médial, pourtant souvent observées après rupture du ligament croisé antérieur (LCA). Une hyperlaxité du genou non lésé est reconnue comme un facteur de risque de rupture du LCA et pourrait l’être pour d’autres lésions. Le but de cette étude est de comparer la laxité antérieure et rotatoire du genou non lésé des patients avec une rupture du LCA en fonction de la présence ou non d’une lésion de la rampe.

BackgroundModern running shoes come in variable heel-to-toe drops, but it is currently unknown if this feature plays a role in the prevention of injuries.ObjectiveTo determine if the drop of conventional cushioned running shoes influences injury risk and whether running regularity (>6 months of regular practice over the previous year) modifies this association.DesignDouble-blind randomised controlled trial, with a 6-month follow-up.SettingLeisure-time distance runners.ParticipantsStudy participants (n=553) were recruited via advertisements in local newspapers. They were required to report any running activity, sport practice and injury using a dedicated internet platform.InterventionRunning shoes with a drop of 10 mm (D10, n=176), 6 mm (D6, n=190) or 0 mm (D0, n=187). Apart from the shoe drop, the 3 versions were strictly identical. A stratified analysis was conducted according to the participants' running regularity.Main Outcome MeasurementsFirst running-related injury self-reported by the participants, and systematically verified by email or phone call. Cox regression analyses were used to compare injury risk between exposure groups.Results136 of the participants (25%) sustained at least one injury. The proportion of injured participants were 21.6%, 27.4% and 24.6% in the D10, D6 and D0 groups, respectively. The overall injury risk was not different among the participants who had received the D6 version (hazard rate ratios – HR=1.30; 95% confidence intervals −95% CI=0.86–1.98) or the D0 version (HR=1.17; 95% CI=0.76–1.80) when compared to the conventional D10 version. The stratified analysis revealed that low drop shoes (D6 and D0 grouped together) were associated with a lower injury risk in occasional runners (HR=0.48; 95% CI=0.23–0.98), and with a higher injury risk in regular runners (HR=1.67; 95% CI=1.07–2.62).ConclusionsOverall, injury risk was not influenced by the drop of conventional cushioned running shoes, yet this association may be modified by the runner's profile.

Les lésions méniscosynoviales du ménisque interne survenant dans le cadre des lésions du ligament croisé antérieur (LCA) ne sont pas rares. Même si elles ont récemment bénéficié d’une attention accrue, leurs circonstances de survenue sont encore insuffisamment connues. Le but de cette étude était de mettre en évidence les facteurs épidémiologiques et lésionnels associés à ce type de lésion pour déterminer chez quels patients l’exploration arthroscopique du compartiment postéromédial serait bénéfique.

Experiments were conducted to determine the effects of non-frozen and frozen storage using two different media on calcium homeostasis compared to fresh semen. One volume of semen was stored at 4°C in an oxygen atmosphere for up to 48 h in three volumes two different media consisting of a modified buffered salt solution (mHBSS) and Tris-NaCl (T350) adjusted to 350 mOsm/kg and pH8. In contrast to our previous cryopreservation studies, a recent study of cryopreservation of striped bass sperm using differential scanning calorimetry indicated that cooling rates of 14-20°C were for optimum survival. We decided to reevaluate semen cryopreservation of striped bass semen by freezing in mHBSS and T350 including 75 mM glycine and 7.5% DMSO (final concentrations) and cooling at 40, 30, 20, 15, and 10°C/min to -120 °C and plunging into liquid nitrogen. Semen was stored in liquid form and frozen at five different cooling rates on viability and calcium homeostasis as determined by flow cytometry and ATP content as determined by Luciferin-Luciferase bioluminescence assay. Post-thaw sperm viability (% SYBR-14 positive/propidium iodide (PI) negative cells) at 15 min post-thaw sperm was 84, 76, 82, 78, and 71%, respectively, for freezing at cooling rates of 40, 30, 20, 15, and 10°C/min. Survival at 40°C/min was greater (P < 0.05) than that at 10, 15, or 30°C/min, but not different than 20°C/min; medium type had no effect on viability. Cooling rate had no effect on sperm ATP content; however ATP was greater (P < 0.05) in sperm frozen in mHBSS than T350 during the first 5 min post-thaw prior to decreasing to essentially zero in both media treatments by 15 min post-thaw. Calcium homeostasis was defined as the ability to maintain low Fluo-3 fluorescence in viable cells (propidium iodide negative) during a 30 min incubation of Fluo-3 loaded sperm. Compared to fresh sperm, stored and thawed viable sperm lost the ability to maintain low intracellular calcium even in the absence of added calcium; positive Fluo-3 fluorescence was found in 3.4% of viable fresh cells and increased (P < 0.05) to 62.9 and 73%, respectively, at 24 and 48 h during storage in mHBSS and T350 and increased to 30% in viable thawed sperm. Viability (% PI negative cells) was 98% at 1 h and decreased (P < 0.05) to 86% after 48 h of non-frozen storage. In conclusion, sperm cells impervious to PI after non-frozen or frozen storage were unable to maintain low intracellular calcium content. The inability to regulate intracellular calcium may be related to the reduced ability to produce ATP and poor motility after 4°C storage or cryopreservation.(poster)