Hypertension, end-stage renal disease and mesangiocapillary glomerulonephritis in methamphetamine users

Background: Methamphetamine abuse has risen dramatically in South Africa. The chronic effects of abuse on the kidneys and blood pressure have not been documented. This study reviewed patients referred for evaluation of kidney disease and/or hypertension, who had been abusing methamphetamines.Methods: The records of patients referred to the renal unit between 2005 and 2013 who had been using methamphetamines were retrospectively reviewed. Patient demographics, biophysical parameters, blood pressure, renal function, renal ultrasound and biopsy findings, complications of chronic kidney disease and comorbidities were recorded.Results: Forty-seven patients were included in the study. Their mean age was 29 years. Hypertension was present in 42 (89.4%) of patients, with malignant hypertension in 21 (44.7%). Forty-five (95.7%) had chronic kidney disease (CKD), and 26 (55.3%) had end-stage renal disease. Renal biopsies were performed in 24 patients. Twelve (50.0%) of the biopsies showed hypertensive changes and 14 (58.3%) mesangiocapillary glomerulonephritis type 1, with deposition of IgM and C3 complement.Conclusion: Methamphetamine use is associated with severe hypertension, mesangiocapillary glomerulonephritis and CKD

A comparison of rugby union match demands between age group categories in UK representative adolescent players

The physical match demands for professional rugby union are well established (Cahill et al., 2013, Journal of Sports Science, 31, 299–237). However, there is a lack of evidence for adolescent players, especially in the UK. Therefore, the purpose of this study was to quantify and compare the demands placed upon adolescent players representing county teams across three age groups (U16, U18 and U20) and two playing positions (forwards and backs). Two county representative games for each age group were assessed, with a total of 112 independent observations collected. Players were classified into age group categories and by position (forwards; U16 [n = 20], U18 [n = 21], U20 [n = 18] and backs; U16 [n = 15], U18 [n = 19], U20 [n = 19]). Match demands were analyzed via a microtechnology unit (OptimEye S5, Catapult Innovations, Melbourne, Australia) that contained a GPS system and triaxial accelerometer sampling at 10 and 100 Hz, respectively. The magnitudes of difference between age groups within positions for locomotive and accelerometer-based variables were investigated using Cohen’s d effect sizes (±90% CL). Institutional ethical approval was granted. For forwards, unclear differences between age groups were observed for total distance (TD), but relative distance (RD) showed very large (U16 vs. U20; d = −2.87 ± 0.53) and large (U18 vs. U20; d = −1.81 ± 0.52) differences between groups. Moderate effect sizes were found for both maximum sprint velocity (Vmax; d = −1.03 ±0.53) and total sprinting distance (d = −0.78 ± 0.53) between U16 and U20. When normalised for time, PlayerLoadSlowTM (PLslow · min-1) increased with age, showing moderate effects for U16 versus U18 (d = 0.68 ± 0.52) and U16 versus U20 (d = 0.80 ± 0.54). For backs, unclear differences between age groups were observed for TD, but RD showed moderate differences U16 versus U20 (d = −0.88 ± 0.58) and U18 versus U20 (d = −1.01 ± 0.54). Small effect sizes were observed for Vmax (d = −0.52 ± 0.54) and total sprinting distance (d = −0.46 ± 0.54) between U18 and U20, whereas U16 versus U20 showed a small difference for Vmax only (d = −0.46 ± 56). PLslow.min-1 increased with age, demonstrating a moderate difference between U16 and U18 (d = 0.86 ± 0.57) and a small difference between U16 and U20 (d = 0.56 ± 0.57). This study shows that the absolute locomotive demands are similar between age groups, although when expressed relative to time, differences were found. This is likely due to difference in playing time between age groups and the consequent fatigue and/or pacing strategies adopted by players. The increase in PLslowmin-1 with age suggests an increase in static exertions. Future research should look to explore the interaction between physical and technical performances at different ages of adolescent rugby

Relationships between training load, sleep duration, and daily wellbeing and recovery measures in youth athletes

Purpose: To assess the relationships between training load, sleep duration and three daily wellbeing, recovery and fatigue measures in youth athletes. Methods: Fifty-two youth athletes completed three maximal countermovement jumps (CMJ), a daily wellbeing questionnaire (DWB), the Perceived Recovery Status scale (PRS), and provided details on their previous day's training loads (training) and self-reported sleep duration (sleep) on four weekdays over a seven week period. Partial correlations, linear mixed models and magnitude-based inferences were used to assess the relationships between the predictor variables (training; sleep) and the dependent variables (CMJ; DWB; PRS). Results: There was no relationship between CMJ and training (r=-0.09; ±0.06) or sleep (r=0.01; ±0.06). The DWB was correlated with sleep (r=0.28; ±0.05, small), but not training (r=-0.05; ±0.06). The PRS was correlated with training (r=-0.23; ±0.05, small), but not sleep (r=0.12; ±0.06). The DWB was sensitive to low sleep(d=-0.33; ±0.11) relative to moderate, PRS was sensitive to high (d=-0.36; ±0.11) and low (d=0.29; ±0.17) training relative to moderate. Conclusions: The PRS is a simple tool to monitor the training response, but DWB may provide a greater understanding of the athlete's overall wellbeing. The CMJ was not associated with the training or sleep response in this population

Dehydration and hyponatremia in professional rugby union players: a cohort study observing english premiership rugby union players during match play, field, and gym training in cool environmental conditions.

Fluid and sodium balance is important for performance and health; however, limited data in rugby union players exist. The purpose of the study was to evaluate body mass (BM) change (dehydration) and blood[Na] change during exercise. Data were collected from 10 premiership rugby union players, over a 4-week period. Observations included match play (23 subject observations), field (45 subject observations), and gym (33 subject observations) training sessions. Arrival urine samples were analyzed for osmolality, and samples during exercise were analyzed for [Na]. Body mass and blood[Na] were determined pre- and postexercise. Sweat[Na] was analyzed from sweat patches worn during exercise, and fluid intake was measured during exercise. Calculations of fluid and Na loss were made. Mean arrival urine osmolality was 423 ± 157 mOsm·kg, suggesting players were adequately hydrated. After match play, field, and gym training, BM loss was 1.0 ± 0.7, 0.3 ± 0.6, and 0.1 ± 0.6%, respectively. Fluid loss was significantly greater during match play (1.404 ± 0.977 kg) than field (1.008 ± 0.447 kg, p = 0.021) and gym training (0.639 ± 0.536 kg, p 1.0%. The findings demonstrate that rugby union players are adequately hydrated on arrival, fluid intake is excessive compared with fluid loss, and some players are at risk of developing hyponatremia

The Reliability of Histamine Pharmacodynamic Response Phenotype Classification in Children With Allergic Disease.

We have identified distinct histamine pharmacodynamic response phenotypes in children with allergic disease utilizing histamine iontophoresis with laser Doppler (HILD). These response phenotypes may be relevant in guiding therapeutic decision making for agents targeting the allergic response pathways. However, the reliability of these response phenotypes has not been assessed. Therefore, we performed HILD in children with allergic rhinitis and/or asthma on two to three separate occasions. HILD response-time data were analyzed in NONMEM using a linked effect PKPD model. Examination of observed vs. classified response phenotypes predicted response plots and the sum of residuals. The intraclass correlation coefficient (ICC) was used to determine the reliability of phenotype classification. Eighty-two percent of children exhibited a reliable histamine response phenotype [intraclass correlation coefficient 0.77 (95% CI 0.44–0.93]. These preliminary results suggest moderate reliability of HILD response phenotype in children. Further exploration is needed to determine contributions to phenotype variability

Modelling for robust feedback control of fluid flows

This paper addresses the problem of designing low-order and linear robust feedback controllers that provide a priori guarantees with respect to stability and performance when applied to a fluid flow. This is challenging, since whilst many flows are governed by a set of nonlinear, partial differential–algebraic equations (the Navier–Stokes equations), the majority of established control system design assumes models of much greater simplicity, in that they are: firstly, linear; secondly, described by ordinary differential equations (ODEs); and thirdly, finite-dimensional. With this in mind, we present a set of techniques that enables the disparity between such models and the underlying flow system to be quantified in a fashion that informs the subsequent design of feedback flow controllers, specifically those based on the H∞ loop-shaping approach. Highlights include the application of a model refinement technique as a means of obtaining low-order models with an associated bound that quantifies the closed-loop degradation incurred by using such finite-dimensional approximations of the underlying flow. In addition, we demonstrate how the influence of the nonlinearity of the flow can be attenuated by a linear feedback controller that employs high loop gain over a select frequency range, and offer an explanation for this in terms of Landahl’s theory of sheared turbulence. To illustrate the application of these techniques, an H∞ loop-shaping controller is designed and applied to the problem of reducing perturbation wall shear stress in plane channel flow. Direct numerical simulation (DNS) results demonstrate robust attenuation of the perturbation shear stresses across a wide range of Reynolds numbers with a single linear controller

The effects of superset configuration on kinetic, kinematic, and perceived exertion in the barbell bench press.

Training that is efficient and effective is of great importance to an athlete. One method of improving efficiency is by incorporating supersets into resistance training routines. However, the structuring of supersets is still unexplored. Therefore, the purpose of this study was to assess the effects of agonist-antagonist (A-A), alternate peripheral (A-P), and similar biomechanical (SB) superset configurations on rate of perceived exertion (RPE), kinetic and kinematic changes during the bench press. 10 subjects performed resistance training protocols in a randomized-crossover design, with magnitude-based inferences assessing changes/differences within and between protocols. Changes in RPE were very likely and almost certainly greater in the A-P and SB protocols when compared with the A-A, while all superset protocols had very likely to almost certain reductions in mean velocity and power from baseline. Reductions in mean velocity and power were almost certainly greater in the SB protocol, with differences between the A-A and A-P protocols being unclear. Decreases in peak force were likely and almost certain in the A-A and SB protocols respectively, with changes in A-P being unclear. Differences between these protocols showed likely greater decreases in SB peak forces when compared to A-A, with all other superset comparisons being unclear. This study demonstrates the importance of exercise selection when incorporating supersets into a training routine. It is suggested that the practitioner uses A-A supersets when aiming to improve training efficiency and minimize reductions in kinetic and kinematic output of the agonist musculature while completing the barbell bench press

Multiple measures are needed to quantify training loads in professional rugby league

To investigate the effect of training mode (conditioning and skills) on multivariate training load relationships in professional rugby league via principal component analysis. Four measures of training load (internal: heart rate exertion index, session rating of perceived exertion; external: PlayerLoad™, individualised high-speed distance) were collected from 23 professional male rugby league players over the course of one 12-wk preseason period. Training was categorised by mode (skills or conditioning) and then subjected to a principal component analysis. Extraction criteria were set at an eigenvalue of greater than 1. Modes that extracted more than 1 principal component were subject to a Varimax rotation. Skills extracted 1 principal component, explaining 57% of the variance. Conditioning extracted 2 principal components (1st: internal; 2nd: external), explaining 85% of the variance. The presence of multiple training load dimensions (principal components) during conditioning training provides further evidence of the influence of training mode on the ability of individual measures of external or internal training load to capture training variance. Consequently, a combination of internal- and external- training load measures is required during certain training modes