The effect of postmortem pH decline rate on mitochondrial apoptosis and tenderness of bovine skeletal muscle during aging

This study aimed to investigate the effect of postmortem pH decline rate on mitochondrial dysfunction-induced apoptosis and bovine muscle tenderness during aging. Protein denaturation, reactive oxygen species (ROS) levels, mitochondrial apoptosis factors, and shear force were assessed in bovine muscles with different pH decline rates. The results showed that compared to the slow group, fast pH decline in bovine muscle significantly increased sarcoplasmic protein denaturation at 6–12 h and mitochondrial ROS levels at 6–24 h (P<0.05), and in turn significantly accentuated mitochondrial dysfunction and cytochrome c oxidation levels (P<0.05), resulting in caspase-3 activation, apoptosis, and reduced muscle shear force (P<0.05). These results demonstrated that the fast postmortem pH decline enhanced mitochondrial apoptosis and bovine muscle tenderization by inducing ROS accumulation during aging.

The Effect of Long-Term Low-Dose Atropine on Refractive Progression in Myopic Australian School Children

Myopia will affect half the global population by 2050 and is a leading cause of vision impairment. High-dose atropine slows myopia progression but with undesirable side-effects. Low-dose atropine is an alternative. We report the effects of 0.01% or 0.005% atropine eye drops on myopia progression in 13 Australian children aged between 2 and 18 years and observed for 2 years without and up to 5 years (mean 2.8 years) with treatment. Prior to treatment, myopia progression was either ‘slow’ (more positive than −0.5D/year; mean −0.19D/year) or ‘fast’ (more negative than −0.5D/year; mean −1.01D/year). Atropine reduced myopic progression rates (slow: −0.07D/year, fast: −0.25D/year, combined: before: −0.74, during: −0.18D/year, p = 0.03). Rebound occurred in 3/4 eyes that ceased atropine. Atropine halved axial growth in the ‘Slow’ group relative to an age-matched model of untreated myopes (0.098 vs. 0.196mm/year, p < 0.001) but was double that in emmetropes (0.051mm/year, p < 0.01). Atropine did not slow axial growth in ‘fast’ progressors compared to the age-matched untreated myope model (0.265 vs. 0.245mm/year, p = 0.754, Power = 0.8). Adverse effects (69% of patients) included dilated pupils (6/13) more common in children with blue eyes (5/7, p = 0.04). Low-dose atropine could not remove initial myopia offsets suggesting treatment should commence in at-risk children as young as possible.

Exercise Intensity during Olympic-Distance Triathlon in Well-Trained Age-Group Athletes: An Observational Study

The aim of this study was to examine the exercise intensity during the swimming, cycling, and running legs of nondraft legal, Olympic-distance triathlons in well-trained, age-group triathletes. Seventeen male triathletes completed incremental swimming, cycling, and running tests to exhaustion. Heart rate (HR) and workload corresponding to aerobic and anaerobic thresholds, maximal workloads, and maximal HR (HRmax) in each exercise mode were analyzed. HR and workload were monitored throughout the race. The intensity distributions in three HR zones for each discipline and five workload zones in cycling and running were quantified. The subjects were then assigned to a fast or slow group based on the total race time (range, 2 h 07 min–2 h 41 min). The mean percentages of HRmax in the swimming, cycling, and running legs were 89.8% ± 3.7%, 91.1% ± 4.4%, and 90.7% ± 5.1%, respectively, for all participants. The mean percentage of HRmax and intensity distributions during the swimming and cycling legs were similar between groups. In the running leg, the faster group spent relatively more time above HR at anaerobic threshold (AnT) and between workload at AnT and maximal workload. In conclusion, well-trained male triathletes performed at very high intensity throughout a nondraft legal, Olympic-distance triathlon race, and sustaining higher intensity during running might play a role in the success of these athletes.

FANCA Polymorphism Is Associated with the Rate of Proliferation in Uterine Leiomyoma in Korea

Uterine leiomyomas are the most common benign gynecologic tumors. This study was aimed to identify single nucleotide polymorphism of Fanconi anemia complementation group A (FANCA), associated with the rate of proliferation in uterine leiomyomas. In vitro study of patient-derived primary-cultured leiomyoma cells and direct sequencing of fresh frozen leiomyoma from each subject was conducted. Leiomyomas obtained from 44 patients who had underwent surgery were both primary-cultured and freshly frozen. Primary-cultured leiomyoma cells were divided into, according to the rate of proliferation, fast and slow groups. Single nucleotide polymorphism (SNP) of FANCA were determined from fresh frozen tissues of each patient using direct sequencing. Direct sequencing revealed a yet unidentified role of FANCA, a caretaker in the DNA damage-response pathway, as a possible biomarker molecule for the prediction of uterine leiomyoma proliferation. We identified that rs2239359 polymorphism, which causes a missense mutation in FANCA, is associated with the rate of proliferation in uterine leiomyomas. The frequency of C allele in the fast group was 35.29% while that in slow group was 11.11% (odds ratio (OR) 4.036 (1.176–13.855), p = 0.0266). We also found that the TC + CC genotype was more frequently observed in the fast group compared with that in the slow group (OR 6.44 (1.90–31.96), p = 0.0227). Taken together, the results in the current study suggested that a FANCA missense mutation may play an important regulatory role in the proliferation of uterine leiomyoma and thus may serve as a prognostic marker.

0294 Baseline Response Speed Predicts Locus Coeruleus Integrity Change After Sleep Deprivation

Introduction Locus coeruleus (LC) is the major source of norepinephrine (NE) in the brain, which plays a key role in maintaining arousal and alertness. Sleep loss significantly impairs arousal and alertness. However, it is unknown whether sleep loss disrupts LC integrity, which can be measured non-invasively by diffusion tensor imaging (DTI). In the current study, we used DTI to examine the effects of one night of acute total sleep deprivation (TSD) on fractional anisotropy (FA), an index reflecting fiber density, axonal diameter and myelination. Methods We analyzed DTI and psychomotor vigilance test (PVT) data from N=54 health adults (23 females, age range 21–50 years) from a well controlled in-laboratory sleep deprivation study. Participants were randomized to either a TSD condition (n=40) without sleep on night 2, or a control condition (n=14) with no sleep loss. Standard DTI scans were conducted on the morning of day 2 and day 3 between 0700h-1000h. The PVT reciprocal response time (RRT) was used to measure individual’s response speed at baseline without sleep loss. LC regions-of-interest (ROI) were defined by standard templates from Keren et al. (2009). Imaging data were analyzed using FSL toolbox. Results For the whole TSD group, no differences were found in the LC FA values before and after sleep deprivation (p &gt; .2). However, when dividing the TSD group to a slow group and a fast group based on their baseline PVT response speed, significantly increased LC FA were found in the slow group (p = .007) but not in the fast group (p &gt; .4). The PVT RRT negatively correlated with LC FA value changes after TSD (r = -.44, p = .004). No correlations were found between the PVT RRT and LC FA changes in the control group. Conclusion Our results showed that baseline vigilance response speed correlated with LC integrity change after sleep deprivation, with slower response exhibiting greater changes in LC integrity. These findings support the key role of LC-NE system in the regulation of alertness and arousal. Support Supported in part by NIH grants R01-HL102119, R01-MH107571, R21-AG051981. CTRC UL1RR024134, and P30-NS045839.

The Relationship between Walking Speed and Step Length in Older Aged Patients

Compared with elderly people who have not experienced falls, those who have were reported to have a shortened step length, large fluctuations in their pace, and a slow walking speed. The purpose of this study was to elucidate the step length required to maintain a walking speed of 1.0 m/s in patients aged 75 years or older. We measured the 10 m maximum walking speed in patients aged 75 years or older and divided them into the following two groups: Those who could walk 1.0 m/s or faster (fast group) and those who could not (slow group). Step length was determined from the number of steps taken during the 10 m-maximum walking speed test, and the step length-to-height ratio was calculated. Isometric knee extension muscle force (kgf), modified functional reach (cm), and one-leg standing time (s) were also measured. We included 261 patients (average age: 82.1 years, 50.6% men) in this study. The fast group included 119 participants, and the slow group included 142 participants. In a regression logistic analysis, knee extension muscle force (p = 0.03) and step length-to-height ratio (p < 0.01) were determined as factors significantly related to the fast group. As a result of ROC curve analysis, a step length-to-height ratio of 31.0% could discriminate between the two walking speed groups. The results suggest that the step length-to-height ratio required to maintain a walking speed of 1.0 m/s is 31.0% in patients aged 75 years or older.

Effect of music tempo on operating room preparation time

Most operating rooms around the world play music, both during the surgeries and in between cases. We investigated whether music tempo (fast or slow) can affect the operating room preparation time in between surgeries (turnover time) in an ambulatory outpatient surgical centre setting. We compiled two playlists, one with fast upbeat tempo and the other with slow relaxing tempo. Each of the playlists was played throughout the workday in the operating room for one week with the same surgeon and nursing staff. The turnover times for each case were analysed. Inclusion criteria were standard cataract extraction with intraocular lens implant surgery. Exclusion criteria were any external reasons causing delays in the turnover time (such as anaesthesia team break time, computer system down, etc.). The turnover time from 32 cases in the slow group and 26 cases in the fast group were compared with Student’s t test. The turnover time was significantly faster in the fast group versus the slow group (17.0 ± 0.60 vs. 20.1 ± 0.96, p < 0.03). Our study demonstrated that fast music tempo in the operating room can significantly reduce turnover time. This improved efficiency could potentially lead to significant cost savings in the healthcare sector.

Differences in upper gastrointestinal neoplasm detection rates based on inspection time and esophagogastroduodenoscopy training

Background and study aims Esophagogastroduodenoscopy (EGD) has utility in early detection of upper gastrointestinal (UGI) neoplasms. However, previous studies report shorter inspection times and inexperienced endoscopists contribute to overlooking gastric neoplasms. We investigated neoplasm detection rates according to inspection time and extent of EGD training. Patients and methods In this retrospective observational study, we reviewed routine EGDs for 3,925 consecutive cases between October 2014 and March 2015. We divided the endoscopists into three groups based on median inspection time during EGD without undergoing biopsy. Using cut-off median inspection times of 7 and 10 minutes, three, five, and eight endoscopists were classified into the fast, moderate, and slow groups, respectively. We compared detection rates according to inspection time and the extent of EGD training. Results The median inspection time among all endoscopists was 9.3 minutes (range, 6.6 – 12.0 min). The detection rate for UGI neoplasms was as follows: fast group, 3.6%; moderate group, 3.3 %; and slow group, 3.1 % (P = 0.807). The median inspection time was significantly shorter among the intensive training ≥ 1-year group than among the < 1-year group (< 1-year: median 6.3 min; range 8.2 – 13.9 min, ≥ 1-year: median 8.9 min; range 6.4 – 11.4 min, P < 0.001). The detection rate for UGI neoplasms was significantly higher among the intensive training ≥ 1-year group than among the < 1-year group (< 1-year: 2.2 %; ≥ 1-year: 3.7 %, OR = 1.65, 95 % CI: 1.02 – 2.68, P = 0.041). Conclusions There was no association between inspection times and neoplasm detection rates. The quality of EGD, as measured by neoplasm detection rates, may be improved by ≥ 1-year of intensive training.

Evaluating Performance During Maximum Effort Vertical Jump Landings

The ability to rapidly complete a jump landing has received little attention in the literature despite the need for rapid performance in a number of sports. As such, our purpose was to investigate differences between groups of individuals who land quickly (FAST) and slowly (SLOW) relative to peak vertical ground reaction forces (vGRFs), loading rates, rates of vGRF attenuation, contributions to lower extremity mechanical energy absorption at the involved joints, and the onsets of preparatory joint flexion/dorsiflexion. Twenty-four healthy adults (26.1 [3.3] y, 75.7 [18.9] kg, 1.7 [0.1] m) were stratified into FAST and SLOW groups based on landing time across 8 jump-landing trials. Independent t tests (α = .05) and effect sizes (ESs; large ≥ 0.8) compared differences between groups. A greater rate of vGRF attenuation (P = .02; ES = 0.95) was detected in the FAST group. The FAST group also exhibited greater contributions to lower extremity energy absorption at the ankle (P = .03; ES = 0.98) and knee (P = .03; ES = 0.99) during loading and attenuation, respectively. The SLOW group exhibited greater contributions to energy absorption at the hip during loading (P = .02; ES = 1.10). Results suggest that individuals who land quickly utilize different energy absorption strategies than individuals who land slowly. Ultimately, the FAST group’s strategy resulted in superior landing performance (more rapid landing time).

A threshold trajectory was revealed by isolating the effects of hemoglobin rate of rise in anemia of chronic kidney disease

Background: To assess cardiovascular risk among various hemoglobin (Hb) rates of rise (RoR) in chronic kidney disease (CKD) patients with anemia who have initiated therapy with erythropoiesis stimulating agents (ESAs). Methods: Observational cohort of CKD patients initiating ESA therapy from the Centricity® database, 1990–2011. Proportional hazards models tested the hypothesis that a slower Hb RoR (0 < g/dl/month ⩽ 0.125) is associated with a lower cardiovascular (CV) incidence [composite of fatal/nonfatal myocardial infarction (MI) and stroke] compared with faster RoR (0.125 < g/dl/month ⩽ 2.0, and >2.0 g/dl/month). Results: A total of 9220 patients receiving ESAs were followed for an average of 3.1 years. Slow (group B) RoR versus medium (group C′) and fast (group D′) RoR in Hb, throughout all Hb milestones, was associated with lower risk of the composite endpoint [B (slow) versus D′ (fast) [hazard ratio (HR) = 0.20 (0.11, 0.39), p < 0.0001]; B versus C′ (medium) [HR = 0.34 (0.19, 0.62), p = 0.0004], and C′ versus D′ [HR = 0.60 (0.42, 0.85), p = 0.005]]. Within achieved Hb milestones, HRs were: B versus D′ at milestone ⩾ 14.1 g/dl [HR = 0.17 (0.05, 0.56); p = 0.004] and at milestone 12.6−14.0 [HR = 0.18 (0.07, 0.46), p = 0.0004]. Conclusion: Rapid Hb rise is associated with adverse CV outcomes, with markedly lower risk for rates below a threshold trajectory of 0.125 g/dl/month, even with complete correction.