Validation of the Mywellness Key in Walking and Running Speeds

This study was performed to assess the validity of the MyWellness Key (MWK) accelerometer during a treadmill-based protocol. The identification of different exercise intensities is imperative to objectively measure time spent at a specified exercise intensity. Thirty subjects, 15 men and 15 women (age = 24.5 ± 2.6 years; body mass index = 22.5 ± 2.5 kg·m^-1), participated in a 4-phase treadmill protocol (5 minutes each one) using three different walking velocities (3, 4.5, and 6 km·h^-1) and run (8 km·h^-1) while outfitted with a MWK uniaxial accelerometer. Oxygen consumption was measured by indirect calorimetry (IC_VO2). Results: The relationship between VO₂ predicted from MWK (MWK_VO2) and oxygen consumption (VO₂ (IC_VO2)), yielded a high and significant correlation (r = 0. 944; p < 0.001) with standard error of estimate (SEE) = 2.42 mL·kg^-1·min^-1. The average differences between the two methods (MWK_VO2 - IC_VO2) were -0.79 (-8. 8% at 3 km·h^-1), -0.02 (-0.2% at 4.5 km·h^-1), 0.51 (3.3% at 6 km·h^-1) and -0.74 (-2.7% at 8 km·h^-1) ml·kg^-1·min^-1. Only the 3 km·h^-1 speed showed a difference when compared to the criterion measure (p < 0.001). Bland and Altman analysis revealed less than a 1 MET difference in the mean at each point estimate and relatively tight distribution with the standard errors, especially with the 2 moderate walking speeds. Conclusions: We found a high correlation between oxygen utilization and the MWK with low standard errors estimates. This indicates that this accelerometer can be used to identify exercise intensities that are related to walking and running.

Key points

• First laboratory validation of a new uniaxial accelerometer, the MyWellness Key.
• Results indicate a good exercise intensity prediction during walking at moderate to high speeds.
• Comparing with other laboratory validations, MyWellness Key exercise intensity detection is aligned with other accelerometers.
• MyWellness Key can be used to give valid measurements for a range of ambulatory activity in addition to the capabilities to give real-time feedback to the participant in health promotion studies.

Key words: Accelerometry, Indirect Calorimetry, Measurement, Physical Activity     

Constraint-Led Changes in Internal Variability in Running

We investigated the effect of a one-time application of elastic constraints on movement-inherent variability during treadmill running. Eleven males ran two 35-min intervals while surface EMG was measured. In one of two 35-min intervals, after 10 min of running without tubes, elastic tubes (between hip and heels) were attached, followed by another 5 min of running without tubes. To assess variability, stride-to-stride iEMG variability was calculated. Significant increases in variability (36 % to 74 %) were observed during tube running, whereas running without tubes after the tube running block showed no significant differences. Results show that elastic tubes affect variability on a muscular level despite the constant environmental conditions and underline the nervous system''s adaptability to cope with somehow unpredictable constraints since stride duration was unaltered.

Key points

• The elastic constraints led to an increase in iEMG variability but left stride duration variability unaltered.
• Runners adapted to the elastic cords, evident in an iEMG variability decrease over time towards normal running.
• Hardly any aftermaths were observed in the iEMG analyses when comparing normal running after the constrained running block to normal running.

Key words: Electromyography, adaptation, performance     

Loading of Hip Measured by Hip Contact Forces at Different Speeds of Walking and Running

Exercise plays a pivotal role in maximizing peak bone mass in adulthood and maintaining it through aging, by imposing mechanical loading on the bone that can trigger bone mineralization and growth. The optimal type and intensity of exercise that best enhances bone strength remains, however, poorly characterized, partly because the exact peak loading of the bone produced by the diverse types of exercises is not known. By means of integrated motion capture as an input to dynamic simulations, contact forces acting on the hip of 20 young healthy adults were calculated during walking and running at different speeds. During walking, hip contact forces (HCFs) have a two‐peak profile whereby the first peak increases from 4.22 body weight (BW) to 5.41 BW and the second from 4.37 BW to 5.74 BW, by increasing speed from 3 to 6 km/h. During running, there is only one peak HCF that increases from 7.49 BW to 10.01 BW, by increasing speed from 6 to 12 km/h. Speed related profiles of peak HCFs and ground reaction forces (GRFs) reveal a different progression of the two peaks during walking. Speed has a stronger impact on peak HCFs rather than on peak GRFs during walking and running, suggesting an increasing influence of muscle activity on peak HCF with increased speed. Moreover, results show that the first peak of HCF during walking can be predicted best by hip adduction moment, and the second peak of HCF by hip extension moment. During running, peak HCF can be best predicted by hip adduction moment. The present study contributes hereby to a better understanding of musculoskeletal loading during walking and running in a wide range of speeds, offering valuable information to clinicians and scientists exploring bone loading as a possible nonpharmacological osteogenic stimulus. © 2015 American Society for Bone and Mineral Research.     

S-100 Protein and Neurohistopathologic Changes in a Porcine Model of Acute Lung Injury

Background: Survivors of acute respiratory distress syndrome exhibit neuropsychological sequelae that might be attributable to hippocampal damage. The authors sought to determine the effects of hypoxemia in a pig model of acute lung injury on the hippocampal region and the release of S-100 protein in comparison to a control group in which hypoxemia was induced by reducing the inspired oxygen fraction.

Methods: Hypoxemia was induced in 14 female pigs by repeated lung lavages (lung injury group; n = 7) or by reducing the inspired oxygen fraction (hypoxia-only group; n = 7). Hemodynamic variables, gas exchange, and serum concentrations of S-100 protein were measured at baseline, after induction of acute lung injury, and subsequently for 12 h. Animals were euthanized, and the brains were removed for histopathologic examination.

Results: Comparable blood gases were seen in both groups. Serum S-100 protein concentrations were comparable for both groups at baseline. At all other time points, S-100 concentrations were significantly higher in the lung injury group. Neuropathologic examination showed basophilic and shrunken neurons of the pyramidal cell layer in the hippocampal CA1 subregion of all pigs in the lung injury group. Few abnormalities were seen in the hypoxia-only group.     

昆明白小鼠间同种生精干细胞移植

目的 :研究同种生精干细胞移植的可行性。　方法 :在不采用免疫抑制剂的条件下 ,进行基因型相似的封闭群昆明白小鼠间的同种生精干细胞移植 ,观察其生精恢复情况。每次穿刺右侧睾丸网 ,左侧睾丸作自身对照。结果 :成功移植的小鼠睾丸生精功能基本恢复正常。　结论 :在基因型类似的昆明白小鼠进行同种生精干细胞移植是可行的。     

Predicting Changes in High-Intensity Intermittent Running Performance with Acute Responses to Short Jump Rope Workouts in Children

The aims of the present study were to 1) examine whether individual HR and RPE responses to a jump rope workout could be used to predict changes in high-intensity intermittent running performance in young athletes, and 2) examine the effect of using different methods to determine a smallest worthwhile change (SWC) on the interpretation of group-average and individual changes in the variables. Before and after an 8-week high-intensity training program, 13 children athletes (10.6 ± 0.9 yr) performed a high-intensity running test (30-15 Intermittent Fitness Test, V_IFT) and three jump rope workouts, where HR and RPE were collected. The SWC was defined as either 1/5^th of the between-subjects standard deviation or the variable typical error (CV). After training, the large ~9% improvement in V_IFT was very likely, irrespective of the SWC. Standardized changes were greater for RPE (very likely-to-almost certain, ~30-60% changes, ~4-16 times >SWC) than for HR (likely-to-very likely, ~2-6% changes, ~1-6 times >SWC) responses. Using the CV as the SWC lead to the smallest and greatest changes for HR and RPE, respectively. The predictive value for individual performance changes tended to be better for HR (74-92%) than RPE (69%), and greater when using the CV as the SWC. The predictive value for no-performance change was low for both measures (<26%). Substantial decreases in HR and RPE responses to short jump rope workouts can predict substantial improvements in high-intensity running performance at the individual level. Using the CV of test measures as the SWC might be the better option.

Key points

• Decreased HR and RPE responses to short jump rope workouts can be confidently used to track improvements in high-intensity intermittent running performance in children familiarized with this exercise mode. Rope jumping is a particularly convenient exercise, since it can be performed in a restricted space and allows the testing of a large number of athletes simultaneously.
• We recommend using the CV of the measures (i.e., 3 and 4% for HR and RPE (OMNI scale) responses, respectively) as the SWC.

Key words: Submaximal heart rate, rate of perceived exertion, OMNI scale, 30-15 Intermittent Fitness Test, progressive statistics     

Race as a risk factor in cadaver kidney transplantation.

Recipients of 93 first-cadaver kidney transplants were studied for the effect of recipient and donor race on graft and patient survival. Both graft and patient survival were lower for black recipients than for whites. The difference was not explained by racial mismatch between donor and recipient. Black recipients had more rejection episodes and more instances of bacterial pneumonia. Pretransplant splenectomy reduced the likelihood of rejection episodes for black recipients and increased their rate of graft survival.     

以护士为主导的手术伤口管理团队的构建与运行

目的 探讨以护士为主导的手术伤口管理团队在胸外科患者伤口管理中的作用。 方法 将320例胸外科手术患者按照入院时间分为对照组与观察组各160例。对照组给予手术伤口常规管理。观察组构建以护士为主导的手术伤口管理团队,制定工作职责及目标,优化临床伤口管理流程,形成以患者为中心的伤口管理模式。比较两组患者手术伤口愈合情况、患者恢复情况及患者满意度等指标。 结果 观察组患者局部伤口症状体征评分、伤口愈合时间、引流管带管时间、住院时间、伤口并发症发生率及焦虑评分显著优于对照组,对护理满意度显著高于对照组（P＜0.05,P＜0.01）。 结论 对胸外科患者实施以护士为主导的手术伤口管理模式,有利于促进患者伤口愈合,提高患者满意度和护理服务质量。     

Changes in S100B levels rather than absolute values may be a better marker of severity of septic encephalopathy

Editor—We read with interest the article by Piazza andcolleagues,¹ where they report that elevated S100B levels didnot correlate with the severity of encephalopathy during sepsis.We would like to ask the authors that even though the S100Blevels did not correlate with the severity of     

The Foot in Running

Injuries to the foot and ankle are often encountered in runners, be they highlevel competitors or recreational joggers. Many of these injuries are due to overuse syndromes and training errors; others are related to the running surface or the athlete's footwear. Only with a rational approach to diagnosis can the primary underlying cause be identified so that appropriate treatment can be prescribed. Conservative measures, which include rest, cross-training, orthotic changes, and altering training methods, are often curative. Surgery is usually indicated only after conservative measures have been exhausted. Careful preoperative planning is needed to minimize dissection, thereby optimizing the chance of a return to the preinjury activity level. Preoperative counseling of the patient is also important, so that expectations about the outcome and the rehabilitation requirements are realistic.     

The Effect of Training in Minimalist Running Shoes on Running Economy

The purpose of this study was to examine the effect of minimalist running shoes on oxygen uptake during running before and after a 10-week transition from traditional to minimalist running shoes. Twenty-five recreational runners (no previous experience in minimalist running shoes) participated in submaximal VO₂ testing at a self-selected pace while wearing traditional and minimalist running shoes. Ten of the 25 runners gradually transitioned to minimalist running shoes over 10 weeks (experimental group), while the other 15 maintained their typical training regimen (control group). All participants repeated submaximal VO₂ testing at the end of 10 weeks. Testing included a 3 minute warm-up, 3 minutes of running in the first pair of shoes, and 3 minutes of running in the second pair of shoes. Shoe order was randomized. Average oxygen uptake was calculated during the last minute of running in each condition. The average change from pre- to post-training for the control group during testing in traditional and minimalist shoes was an improvement of 3.1 ± 15.2% and 2.8 ± 16.2%, respectively. The average change from pre- to post-training for the experimental group during testing in traditional and minimalist shoes was an improvement of 8.4 ± 7.2% and 10.4 ± 6.9%, respectively. Data were analyzed using a 2-way repeated measures ANOVA. There were no significant interaction effects, but the overall improvement in running economy across time (6.15%) was significant (p = 0.015). Running in minimalist running shoes improves running economy in experienced, traditionally shod runners, but not significantly more than when running in traditional running shoes. Improvement in running economy in both groups, regardless of shoe type, may have been due to compliance with training over the 10-week study period and/or familiarity with testing procedures.

Key points

• Running in minimalist footwear did not result in a change in running economy compared to running in traditional footwear prior to 10 weeks of training.
• Both groups (control and experimental) showed an improvement in running economy in both types of shoes after 10 weeks of training.
• After transitioning to minimalist running shoes, running economy was not significantly different while running in traditional or minimalist footwear.

Key words: Footwear, training, oxygen consumption     

小鼠同种生精干细胞移植后的形态学观察

目的 研究同种生精干细胞移植的后的形态学变化。方法 在不采用免疫抑制剂的条件下,在基因型相似的封闭群昆明白小鼠间进行同种生精干细胞移植,移植后3个月,观察其生精恢复情况。结果 形态学证实,成功移植的小鼠生精功能基本恢复正常。结论 在基因型类似的昆明白小鼠进行同种生精干细胞移植是可行的。     

Race is a major determinant of secondary hyperparathyroidism in uremic patients

In the general population, blacks have higher parathyroid gland mass and circulating parathyroid hormone (PTH) levels than whites. This may predispose black patients to more severe parathyroid disease when renal failure develops. Therefore, racial differences in the severity of uremic hyperparathyroidism were examined in a population of patients with end-stage renal disease (ESRD). Among ESRD patients receiving hemodialysis or peritoneal dialysis, two or more values of intact PTH (immunoradiometric assay, pg/ml) obtained at least 90 d apart were available in 1270 prevalent cases (61.1% blacks, 51% males, and 31.1% diabetic), including 466 incident cases with onset of ESRD after 1993. Maximum PTH levels were analyzed as a function of race, gender, age, diabetic status, and levels of serum calcium, phosphorus, alkaline phosphatase, and aluminum. Using a stepwise multiple regression model, the determinants of maximum PTH in the order of their importance were black race, serum phosphorus, absence of diabetes, younger age, serum calcium, and female gender. The maximum PTH levels averaged 641.7 in blacks and 346.0 in whites after adjusting for age, gender, diabetic status, serum calcium, and phosphorus (P < 0.0001). In blacks compared with whites, the odds ratio (95% confidence interval) for adynamic bone disease (maximum PTH <150 pg/ml) was 0.26 (0.17 to 0.41), whereas the odds ratio for hyperparathyroid bone disease (mean PTH >500 pg/ml) was 4.4 (2.10 to 9.25). Race is a major independent determinant of uremic secondary hyperparathyroidism. Among ESRD patients, blacks may be at an increased risk for hyperparathyroid bone disease and whites for adynamic bone disease.     

Race, ethnicity and urolithiasis: a critical review

Using combinations of the key words urolithiasis, kidney stones, race, ethnicity, population group in Google Scholar and Pubmed, a literature search identified 40 articles. Of these, 33 satisfied the principal inclusion criterion of studies involving comparison of at least two groups in which there is a perceived difference in stone occurrence. Studies were classified as “weak” (no attempt to account for inter-racial or inter-ethnic group differences in stone occurrence), “soft” (speculative explanations reached by default) or “hard” (explanations based on empirically measured lithogenic risk factors). Only 12 studies (36 %) fell into the latter category. Among these, a wide diversity of lithogenic factors was invoked to explain inter-group differences in stone rates. Traditional urinary physicochemical risk factors do not convincingly account for these differences. Studies have failed to yield a consolidated and unifying theory which compellingly explains racial and ethnic differences in urolithiasis.