BACKGROUND A single-group, phase 1-2 study indicated that eltrombopag improved the efficacy of standard immunosuppressive therapy that entailed horse antithymocyte globulin (ATG) plus cyclosporine in patients with severe aplastic anemia. METHODS In this prospective, investigator-led, open-label, multicenter, randomized, phase 3 trial, we compared the efficacy and safety of horse ATG plus cyclosporine with or without eltrombopag as front-line therapy in previously untreated patients with severe aplastic anemia. The primary end point was a hematologic complete response at 3 months. RESULTS Patients were assigned to receive immunosuppressive therapy (Group A, 101 patients) or immunosuppressive therapy plus eltrombopag (Group B, 96 patients). The percentage of patients who had a complete response at 3 months was 10% in Group A and 22% in Group B (odds ratio, 3.2; 95% confidence interval [CI], 1.3 to 7.8; P=0.01). At 6 months, the overall response rate (the percentage of patients who had a complete or partial response) was 41% in Group A and 68% in Group B. The median times to the first response were 8.8 months (Group A) and 3.0 months (Group B). The incidence of severe adverse events was similar in the two groups. With a median follow-up of 24 months, a karyotypic abnormality that was classified as myelodysplastic syndrome developed in 1 patient (Group A) and 2 patients (Group B); event-free survival was 34% and 46%, respectively. Somatic mutations were detected in 29% (Group A) and 31% (Group B) of the patients at baseline; these percentages increased to 66% and 55%, respectively, at 6 months, without affecting the hematologic response and 2-year outcome. CONCLUSIONS The addition of eltrombopag to standard immunosuppressive therapy improved the rate, rapidity, and strength of hematologic response among previously untreated patients with severe aplastic anemia, without additional toxic effects.

Myelodysplastic syndromes (MDS) represent a heterogeneous group of hematological clonal disorders. Here, we have tested the bone marrow (BM) cells from 38 MDS patients covering all risk groups in two immunodeficient mouse models: NSG and NSG-S. Our data show comparable level of engraftment in both models. The level of engraftment was patient specific with no correlation to any specific MDS risk group. Furthermore, the co-injection of mesenchymal stromal cells (MSCs) did not improve the level of engraftment. Finally, we have developed an in vitro two-dimensional co-culture system as an alternative tool to in vivo. Using our in vitro system, we have been able to co-culture CD34(+) cells from MDS patient BM on auto-and/or allogeneic MSCs over 4 weeks with a fold expansion of up to 600 times. More importantly, these expanded cells conserved their MDS clonal architecture as well as genomic integrity.

Although next-generation sequencing has allowed for the detection of somatic mutations in myelodysplastic syndromes (MDS), the clinical relevance of variant allele frequency (VAF) for the majority of mutations is unknown. We profiled TP53 and 20 additional genes in our training set of 219 patients with MDS or secondary acute myeloid leukemia with findings confirmed in a validation cohort. When parsed by VAF, TP53 VAF predicted for complex cytogenetics in both the training (P=0.001) and validation set (P<0.0001). MDS patients with a TP53 VAF > 40% had a median overall survival (OS) of 124 days versus an OS that was not reached in patients with VAF <20% (hazard ratio (HR), 3.52; P=0.01) with validation in an independent cohort (HR, 4.94, P=0.01). TP53 VAF further stratified distinct prognostic groups independent of clinical prognostic scoring systems (P=0.0005). In multivariate analysis, only a TP53 VAF >40% was an independent covariate (HR, 1.61; P<0.0001). In addition, SRSF2 VAF predicted for monocytosis (P=0.003), RUNX1 VAF with thrombocytopenia (P=0.01) and SF3B1 with ringed sideroblasts (P=0.001). Together, our study indicates that VAF should be incorporated in patient management and risk stratification in MDS.

Nonsynonymous TP53 exon 4 single-nucleotide polymorphism (SNP), R72P, is linked to cancer and mutagen susceptibility. R72P associations with specific cancer risk, particularly hematological malignancies, have been conflicting. Myelodysplastic syndrome (MDS) with chromosome 5q deletion is characterized by erythroid hypoplasia arising from lineage-specific p53 accumulation resulting from ribosomal insufficiency. We hypothesized that apoptotically diminished R72P C-allele may influence predisposition to del(5q) MDS. Bone marrow and blood DNA was sequenced from 705 MDS cases (333 del(5q), 372 non-del(5q)) and 157 controls. Genotype distribution did not significantly differ between del(5q) cases (12.6% CC, 38.1% CG, 49.2% GG), non-del(5q) cases (9.7% CC, 44.6% CG, 45.7% GG) and controls (7.6% CC, 37.6% CG, 54.8% GG) (P=0.13). Allele frequency did not differ between non-del(5q) and del(5q) cases (P=0.91) but trended towards increased C-allele frequency comparing non-del(5q) (P=0.08) and del(5q) (P=0.10) cases with controls. Median lenalidomide response duration increased proportionate to C-allele dosage in del(5q) patients (2.2 (CC), 1.3 (CG) and 0.89 years (GG)). Furthermore, C-allele homozygosity in del(5q) was associated with prolonged overall and progression-free survival and non-terminal interstitial deletions that excluded 5q34, whereas G-allele homozygozity was associated with inferior outcome and terminal deletions involving 5q34 (P=0.05). These findings comprise the largest MDS R72P SNP analysis.

Bone marrow (BM) genetic abnormalities in myelodysplastic syndrome (MDS) have provided important biological and prognostic information; however, frequent BM sampling in older patients has been associated with significant morbidity. Utilizing single-nucleotide polymorphism array (SNP-A) and targeted gene sequencing (TGS) of 24 frequently mutated genes in MDS, we assessed the concordance of genetic abnormalities in BM and peripheral blood (PB) samples concurrently from 201 MDS patients. SNP-A karyotype in BM was abnormal in 108 (54%) and normal in 93 (46%) patients, with 95% (190/201) having an identical PB karyotype. The median copy number (CN) for deletions was significantly lower in BM (CN:1.4 (1-1.9)) than in PB (CN:1.5 (1-1.95), P<0.001). Using TGS, 71% (130/183) patients had BM somatic mutations with 95% (124/130) having identical mutations in PB. The mutant allele burden was lower in PB (median 27% (1-96%)) compared with BM (median 29% (1-100%); P=0.14) with no significant difference in the number, types of mutations or World Health Organization subtype. In all patients with discordant SNP (n=11) and mutation (n=6) profiles between BM and PB, shared abnormalities were always present irrespective of treatment status. Overall, 86% of patients had a clonal aberration with 95% having identical SNP-A karyotype and mutations in PB, thus enabling frequent assessment of response to treatment and disease evolution especially in patients with fibrotic or hypocellular marrows.

The purpose of this study was to evaluate the effects of β-alanine supplementation on markers of oxidative stress. Twenty-four women (age: 21.7 ± 2.1 years; VO2max: 2.6 ± 0.3 l min−1) were randomly assigned, in a double-blind fashion, to a β-alanine (BA, 2 × 800 mg tablets, 3× daily; CarnoSyn®; n = 13) or placebo (PL, 2 × 800 mg maltodextrin tablets, 3× daily; n = 11) group. A graded oxygen consumption test (VO2max) was performed to evaluate VO2max, time to exhaustion, ventilatory threshold and establish peak velocity (PV). A 40-min treadmill run was used to induce oxidative stress. Total antioxidant capacity, superoxide dismutase, 8-isoprostane (8ISO) and reduced glutathione were measured. Heart rate and ratings of perceived exertion were recorded during the 40 min run. Separate three- [4 × 2 × 2; acute (base vs. IP vs. 2 vs. 4 h) × chronic (pre- vs. post-) × treatment (BA vs. PL)] and two- [2 × 2; time (pre-supplement vs. post-supplement) × treatment (BA vs. PL)] way ANOVAs were used for analyses. There was a significant increase in VO2max (p = 0.009), independent of treatment, with no significant changes in TTE (p = 0.074) or VT (p = 0.344). Ratings of perceived exertion values were significantly improved from pre- to post-supplementation for the BA group only at 40 min (p = 0.02). The ANOVA model demonstrated no significant treatment effects on oxidative stress. The chronic effects of BA supplementation demonstrated little antioxidant potential, in women, and little influence on aerobic performance assessments.

Critical velocity (CV) has been used as a practical method to predict maximal average velocity in a variety of sports, such as running and swimming. More recently, it has been shown to be highly correlated to 2000 m rowing performance in male rowers. Minimal literature exists examining selected physiological variables in female rowers, and currently, there has been no CV model applied to collegiate, female rowers. PURPOSE: The aim of the present study was to validate the use of the CV test as a means of predicting 2000 m performance in female collegiate rowers, and to study the relationship of selected physiological variables on performance times. METHODS: Thirty-five female collegiate rowers (mean ± SD; age 19.38 ± 1.3 yrs; height: 170.27 ± 6.07 cm; weight: 69.58 ± .31kg) volunteered to participate in this study. Rowers were divided into two categories based on rowing experience, varsity (V; >1yr collegiate experience, V̇o2peak: 3.14 ± 0.31L/min) and novice (N; <1 year collegiate experience, V̇o2peak: 2.88 ± 0.20 L/min). All rowers performed two continuous graded maximal oxygen consumption tests (familiarization and baseline) to establish peak maximal oxygen uptake (V̇o2peak, L·min-1), peak power output (PPO) in watts, and ventilatory threshold(VT, L·min-1). A calibrated metabolic cart (Parvomedics True One 2400, Sandy, Utah)with a two-way valve(Hans Rudolph 2700, Kansas City, MO)was used for all gas exchange analysis during the V̇o2peak tests. Rowers then completed a CV test, consisting of four time trials at varying distances (200 m, 600 m, 800 m, and 1000 m) on two separate days, with 15 minutes rest between trials. Following the CV test, rowers completed a 2000m time-trial. All tests were completed on a Concept II, Model D rowing ergometer. RESULTS: V̇o2peak showed the highest correlation to 2000 m performance (r = .923) in V rowers with strong correlations also observed for PPO and CV (r = .866 and r = .856, respectively). Stepwise regression showed that V̇o2peak was the best single predictor of 2000 m performance, accounting for 85% of the variability in performance. In contrast, CV demonstrated the highest correlation to 2000 m performance in N rowers (r = .733), explaining 54% of the variability in performance. CONCLUSIONS: The current findings suggest V̇o2peak is the best overall indicator of 2000 m performance time for experienced female rowers. PRACTICAL APPLICATIONS: Due to the high-level of importance of V̇o2PEAK in rowers, it is suggested that rowers and coaches consider this variable when designing training programs. Future studies are needed to examine different training protocols (i.e. moderate-intensity, continuous rowing vs. high-intensity interval training) to determine which program has the greatest impact on improving V̇o2peak and 2,000 m performance times. However, when metabolic equipment is unavailable for V̇o2peak measurement, the use of the CV test may be an attractive alternative for predicting 2000 m performance, especially in novice rowers.

Accurately tracking changes in fat-free mass (FFM) in older adults is of importance due to the reduction of muscle mass with age and the subsequent onset of sarcopenia. PURPOSE: The purpose of the current investigation was to determine if dual-energy X-ray absorptiometry (DXA) could accurately track FFM changes in older adults compared to a criterion four-compartment (4C) model. METHODS: Forty men (n = 20) and women (n = 20) participated in a six-month progressive strength training program while the remaining men (n = 22) and women (n = 24) acted as controls. Participants consisted of healthy older adults ages 65 to 88. Body composition was assessed using DXA and a 4C model that included bone mineral content from DXA, body volume from air-displacement plethysmography, and total body water using deuterium oxide. RESULTS: Mean delta differences in both the exercise (0.211 kg) and control (−0.007 kg) groups were not significant (p > 0.26) for either men or women comparing DXA to the 4C model. Individual differences were less than +/− 2.97 kg. DXA accurately tracked all but one subject in the exercise group (5%) and one subject in the control group (3%) when the minimal difference needed to be considered real (MD) for DXA (1.44kg) was exceeded or not met, respectively. CONCLUSION: With an overall individual accuracy of 96%, DXA can be considered a valid tool for tracking FFM changes in aging adults. DXA produced valid delta values compared to the 4C model in both men and women in the control and exercise groups. Due to the non-significant CE values, low TE values, and high individual accuracy, DXA appears to be valid for tracking changes in older adults. However, caution should be used when interpreting values that have not met the MD. PRACTICAL APPLICATION: When the MD for DXA FFM is exceeded, DXA can be used for individually assessing FFM changes in aging adults with an accuracy of 96%. However, this accuracy only represents individual directional changes and not the magnitude of the FFM changes. Therefore, individual errors may be as large as +/− 2.96 kg when quantifying changes in FFM using DXA compared to a 4C model. Nonetheless, DXA can be considered an accurate tool for tracking FFM in older men and women when changes reported by DXA exceed 1.44 kg. ACKNOWLEDGEMENTS: We would like to thank Abbott Nutrition for funding this study.

This study evaluated the effects of creatine (Cr) loading and sex differences on aerobic running performance. 27 men (mean±SD; age: 22.2±3.1 years, ht: 179.5±8.7 cm, wt: 78.0±9.8 kg) and 28 women (age: 21.2±2.1 years, ht: 166.0±5.8 cm, wt: 63.4±8.9 kg) were randomly assigned to either creatine (Cr, di-creatine citrate; n=27) or a placebo (PL; n=28) group, ingesting 1 packet 4 times daily (total of 20 g/day) for 5 days. Aerobic power (maximal oxygen consumption: VO2max) was assessed before and after supplementation using open circuit spirometry (Parvo-Medics) during graded exercise tests on a treadmill. 4 high-speed runs to exhaustion were conducted at 110, 105, 100, and 90% of peak velocity to determine critical velocity (CV). Distances achieved were plotted over times-to-exhaustion and linear regression was used to determine the slopes (critical velocity, CV) assessing aerobic performance. The results indicated that Cr loading did not positively or negatively influence VO2max, CV, time to exhaustion or body mass (p>0.05). These results suggest Cr supplementation may be used in aerobic running activities without detriments to performance.

Although the existing body of creatine (Cr) literature is robust and supports its role as a metabolic ergogenic aid, a limited number of studies have examined the effects of Cr supplementation on neuromuscular function. PURPOSE: The purpose of the present study was to examine the effects of fatigue on voluntary peak force (PF), percent voluntary activation (%VA), peak twitch force (PTF), peak twitch rate of force development (RFD), and electromyographic (EMG) amplitude of the soleus (SOL) and medial gastrocneimus (MG) muscles prior to and following short term creatine loading. METHODS: Using a double-blind, placebo-controlled, randomized design, 29 moderately trained participants were assigned to a creatine (Cr; n = 16, age: 21.9 ± 2.6 yrs, stature: 174.6 ± 10.9 cm, body mass: 73.0 ± 10.9 kg) or placebo (Pl; n = 13, age: 22.2 ± 3.5 yrs, stature: 175.7 ± 9.5 cm; body mass: 71.9 ± 14.2 kg) group. Subjects supplemented their diet four times daily for five days with 5g of Cr + 15g dextrose (Cr) or 20g dextrose (Pl). At baseline (week 1) and post-testing (week 2) all subjects performed an isometric maximal voluntary contraction (MVC) and the twitch interpolation technique prior to and immediately following a four minute fatigue protocol of the plantar flexor muscles on a custom-built load cell apparatus attached to a calibrated isokinetic dynamometer. The fatiguing protocol included four sets of 10 intermittent isometric contractions (7-sec on / 3-sec off) at 70% of MVC. Additionally, a familiarization session was completed prior to baseline measurements. Separate three-way mixed factorial ANOVAs [acute (pre vs. post) x chronic (week 1 vs. week 2) x treatment (Cr vs. Pl)] were used to analyze the PF, %VA, PTF and RFD. A four-way mixed factorial ANOVA [muscle (SOL vs. MG) x acute (pre vs. post) x chronic (week 1 vs. week 2) x treatment (Cr vs. Pl)] was used to analyze EMG values. RESULTS: The acute bout of fatiguing contractions resulted in a significant main effect for acute resulting in a loss in voluntary strength (–15.7%, P < 0.001), %VA (−7.3%, P = 0.003) and an increase in RFD (4.7%, P = 0.037) for both groups. There was a significant chronic × treatment interaction for MVC. The chronic effects of Cr supplementation from week 1 to week 2 demonstrated a maintenance in voluntary strength (MVC) for the Cr group (−0.5%, P = 0.710) while the PL group showed a significant decline in strength (−5.8%, P = 0.035). There was also a significant chronic × treatment interaction for the evoked twitch properties, resulting in an increase in PTF (5.7%, P = 0.019) and a non-significant increase in RFD (4.6%, P = 0.071) for the Cr group only. In addition, there was a main effect for treatment for %VA where the Cr group was 7.3% more active than the PL group across all time points (P = 0.023). Furthermore, there was a main effect for chronic where EMG amplitude was higher (20.0%, P = 0.023) for both groups at week 2 compared to week 1. CONCLUSIONS: These findings indicated that chronic Cr supplementation preserved maximal voluntary strength and enhanced evoked twitch properties. However, there were no acute differences between groups before and after the fatiguing protocol. PRACTICAL APPLICATIONS: Cr supplementation enhanced maximal contractile properties, but had a limited influence during a fatiguing bout of exercise in the present study. The ability to maintain maximal force between training sessions may lead to practical increases in strength.

This study examined the acute effects of passive stretching (PS) vs prolonged vibration (VIB) on voluntary peak torque (PT), percent voluntary activation (%VA), peak twitch torque (PTT), passive range of motion (PROM), musculotendinous stiffness (MTS), and surface electromyographic (EMG) and mechanomyographic (MMG) amplitude of the medial gastrocnemius (MG) and soleus (SOL) muscles during isometric maximal voluntary contractions (MVCs) of the plantar flexors. Fifteen healthy men performed the isometric MVCs and PROM assessments before and after 20 min of PS, VIB, and a control (CON) conditions. There were 10% and 5% decreases in voluntary PT, non-significant 3% and 2% decreases in %VA, 9-23% decreases in EMG amplitude of the MG and SOL after the PS and VIB, respectively, with no changes after the CON. PROM increased by 19% and MTS decreased by 38% after the PS, but neither changed after the VIB or CON conditions. Both PS and VIB elicited similar neural deficits (i.e., gamma loop impairment) that may have been responsible for the strength losses. However, mechanical factors related to PROM and MTS cannot be ruled out as contributors to the stretching-induced force deficit.

Objectives: This study examined the effects of 14 days of creatine supplementation on the physical working capacity at fatigue threshold (PWCFT), maximal isometric grip strength (GRIP), sit-to-stand (STS), and body weight (BW) in elderly men and women. Design: Using a double blind cross-over design, fifteen men (n = 7) and women (n = 8) (age +/- SD = 74.5 +/- 6.4 yrs) were randomly assigned to either the creatine (CR) (20g.d(-1) during week 1 decreasing to 10g.d(-1) at week 2) or Placebo (PL) group. After a 4 to 6 week washout period, the subjects were assigned the other treatment. Before (pre) and after (post) the supplementation period, participants performed a discontinuous, cycle ergometry test to determine the PWCFT. In addition, subjects performed STS, GRIP, BW test prior to and post treatment. Setting: Southeastern part of the United States. Results: Significant increases in GRIP (6.7%) and PWCFT (15.6%) from pre- to post-supplementation were found for the CR (p < 0.05) treatment, but no change for the PL treatment was observed. However, no significant change (p > 0.05) was noted for STS or BW for either treatment. Conclusion: These findings suggest that 14 days of CR supplementation may increase upper body grip strength and increase physical working capacity by delaying neuromuscular fatigue in the elderly men and women in this study. While more research is needed, CR supplementation may improve upper body grip strength and lower body muscle endurance which may be important for maintaining health and independent living in elderly men and women.

1441 25 healthy men (age=25±3 yr [mean ± SD]) with various exercise histories were randomly assigned to two groups; each walked at 107 m·min-1 for 40 min or until fatigued, experimental (E) subjects(N=12) on -24% grade and control (C) subjects (N=13) on 0% grade. Before, immediately after, and 24 and 48 h after this exercise, each subject was tested on an inclined (20 °) sled to measure variables related to use of elastic energy by extensor muscles of the lower limbs: maximal jumping height with (CMJ) and without (SJ) counter movement, and efficiencies of series of 20 submaximal CMJs and SJs. Also, at various times pre- and post-exercise, variables that are commonly related to eccentric exercise-induced muscle injury were measured: muscle soreness, plasma CK activity (n=15), flexibility at the hips and trunk (indicated by sit-and-reach test), and knee extensor strength. Exercise caused changes (main effect; P≤0.05) in jumping height consistent with increased storage and use of elastic energy, but there was no difference between E and C conditions; e.g., (CMJ Height)/(SJ Height) = 1.06±0.04 preexercise and 1.10±0.07 24 h postexercise(N=25). Jumping efficiency was not altered; e.g., (CMJ Efficiency)/(SJ Efficiency) = 1.41±0.19 preexercise and 1.41±0.24 24 h postexercise (N=25). Although E subjects reported more soreness, strength(e.g., 603±121 N preexercise and 546±111 N 24 h postexercise[N=25]) and flexibility (e.g., 7.0±10.0 cm preexercise and 5.5±10.8 cm 24 h postexercise [N=25]) were reduced similarly in both groups. There were no statistical changes in plasma CK (e.g., 367±312 U/L preexercise and 460±376 U/L 48 h postexercise [N=15]), although some subjects had values close to or above 1000 U/L. CONCLUSION: In general, both the downhill and the level walking caused similar changes that were consistent with muscle microinjury and increased muscular ability to use elastic energy during the 2- to 4-d postexercise period.