UNASSIGNED: Frailty affects the prognosis and management of patients with heart failure, and is often related with sarcopenia. Also, the serum myostatin (MSTN) involved in the development of sarcopenia and frailty. This study aimed to determine the connection between MSTN level and frailty in older adults with chronic heart failure (CHF).
UNASSIGNED: This prospective case-control study enrolled older adult patients with CHF between May 2019 and May 2021, and analyzed their clinical data.
UNASSIGNED: In this study 75 older adults with CHF were included, 29 of whom were frail. The B-type natriuretic peptide (BNP) levels were significantly higher in frail older adults with CHF than in older adults with CHF who were not frail (316.82 ± 235.64 pg/mL vs 198.61 ± 112.58 pg/mL; P = 0.016). The MSTN levels were significantly higher in frail participants than in participants who were not frail (2.93 ± 1.35 ng/mL vs 2.24 ± 0.84 ng/mL; P = 0.018). Based on multivariable analysis the BNP (odds ratio [OR] = 1.004, 95% confidence interval [CI] = 1 0.001-1.008; P = 0.018) and MSTN (OR = 1.772, 95% CI = 1.079-2.912; P =0 0.024) levels were independently associated with frailty in older adults with CHF.
UNASSIGNED: MSTN is a promising biomarker of frailty in elderly patients with CHF.

Spinal muscular atrophy (SMA) is a rare neuromuscular disorder threating hundreds of thousands of lives worldwide. And the severity of SMA differs among different clinical types, which has been demonstrated to be modified by factors like SMN2, SERF1, NAIP, GTF2H2 and PLS3. However, the severities of many SMA cases, especially the cases within a family, often failed to be explained by these modifiers. Therefore, other modifiers are still waiting to be explored.
In this study, we presented a rare case of SMA discordant family with a mild SMA male patient and a severe SMA female patient. The two SMA cases fulfilled the diagnostic criteria defined by the International SMA Consortium. With whole exome sequencing, we confirmed the heterozygous deletion of exon7 at SMN1 on the parents\' genomes and the homozygous deletions on the two patients\' genomes. The MLPA results confirmed the deletions and indicated that all the family members carry two copies of SMN2, SERF1, NAIP and GTF2H2. Further genomic analysis identified compound heterozygous mutations at TLL2 on the male patient\'s genome, and compound heterozygous mutations at VPS13A and the de novo mutation at AGAP5 on female patient\'s genome. TLL2 is an activator of myostatin, which negatively regulates the growth of skeletal muscle tissue. Mutation in TLL2 has been proved to increase muscular function in mice model. VPS13A encodes proteins that control the cycling of proteins through the trans-Golgi network to endosomes, lysosomes and the plasma membrane. And AGAP5 was reported to have GTPase activator activity.
We reported a case of SMA discordant family and identified mutations at TLL2, VPS13A and AGAP5 on the patients\' genomes. The mutations at TLL2 were predicted to be pathogenic and are likely to alleviate the severity of the male SMA patient. Our finding broadens the spectrum of genetic modifiers of SMA and will contribute to accurate counseling of SMA affected patients and families.

Myokines are produced and released by muscle cells in response to muscular contractions. Endogenous Cushing syndrome (CS) and acromegaly cause significant changes in muscle tissue leading to atrophy or hypertrophy. However, there is no data whether these endocrine abnormalities influence myokine secretion.
To evaluate serum levels of myostatin, interleukin-6 (IL6) and irisin in patients with CS and acromegaly.
Fasting serum samples were taken and stored in aliquot at ≤-20°C from consecutive subjects with clinically evident and biochemically confirmed active CS, acromegaly and healthy volunteers matched by age, sex and body mass index (BMI). Commercially available kits were used to assay serum myokine levels. Grip strength was measured by a dynamometer. Insulin-like growth factor-1 (IGF1) was measured by immunochemiluminescence assay (Liaison), twenty-four hours urine free cortisol (24hUFC) ― by immunochemiluminescence assay (Vitros ECi), salivary free cortisol ― by electrochemiluminescence assay (Cobas). One-way ANOVA was utilized to assess the difference between groups.
We enrolled 88 subjects: 30 patients suffered from CS (group 1), 28 ― acromegaly (2) and 30 matched healthy controls (3) with no difference among the groups in sex, age and BMI (p=0.492, 0.062 and 0.174 respectively). Mean 24hUFC in subjects with CS and mean IGF1 in subjects with acromegaly were significantly higher as compared to other groups (p<0.001). Right-hand grip strength was lower in patients with CS as compared to both patients with acromegaly and healthy subjects (p=0.04). However, among these young adults we did not find statistically significant differences in measured myokines levels: irisin ― p=0.15; IL6 ― p=0.34; myostatin ― p=0.50. There was a significant correlation between myostatin and irisin in the whole group of people and in every separately analyzed subset of patients (p<0.001), but no correlation was found between any measured myokines and 24hUFC or IGF1.
Hypercortisolism or supraphysiological IGF1 levels do not significantly influence serum levels of myostatin, IL6 and irisin in young adults.

Bazyler, CD, Mizuguchi, S, Zourdos, MC, Sato, K, Kavanaugh, AA, DeWeese, BH, Breuel, KF, and Stone, MH. Characteristics of a national level female weightlifter peaking for competition: A case study. J Strength Cond Res 32(11): 3029-3038, 2018-This study investigated physiological and performance changes of a national-level 69 kg female weightlifter after 3 competition phases over a 28-week training period. The athlete first trained for a regional championship (weeks 1-12), followed by a local competition (weeks 13-23) and the national championship (weeks 24-28). Body mass, vastus lateralis cross-sectional area (CSA), and unloaded and loaded squat jump performance were assessed weekly during each 4-week competition phase. Serum biomarkers and dynamic midthigh pulls were assessed before and after each competition phase. Weightlifting performance goals were met for the regional championship (total = 200 kg) and the local competition (total = 193 kg), but not the national championship (total = 196 kg). She lost more body mass in preparation for Nationals (-6.0 kg) compared with regionals (-2.5 kg) and the local competition (+2.2 kg). Vastus lateralis CSA very likely decreased after Nationals (precision = 99%, effect size = 2.08). Her testosterone:cortisol ratio likely increased (88%, 2.64), whereas interleukin-6 (79%, 2.47) and tumor necrosis factor-alpha (81%, 3.59) likely decreased after Nationals. Serum myostatin (99%, 1.95) and decorin (99%, 1.96) very likely decreased after the local competition. Unloaded squat jump height likely increased the week of regionals (89%, 0.95) and the local competition (99%, 1.83), whereas unloaded and loaded squat jump height possibly (69%, 0.99) and likely (82%, 1.52) decreased the week of Nationals. Dynamic midthigh pull vertical displacement likely increased after regionals (93%, 0.84) and likely decreased after Nationals (94%, 0.87). These findings indicate that biomarkers of stress, inflammation, and hypertrophy are related to changes in training volume-load; however, performance measures are needed to assess competition preparedness. Considering the reductions in muscle CSA corresponding with the large reductions in body mass and underperformance at the national championship, sport scientists, and coaches should instruct weightlifters to not attempt large losses in body mass (e.g., >3 kg) close to competition (e.g., <1week).

The aim of this study was to verify how a pair of monozygotic twins would respond to light-emitting diode therapy (LEDT) or placebo combined with a strength-training program during 12 weeks.
This case-control study enrolled a pair of male monozygotic twins, allocated randomly to LEDT or placebo therapies. Light-emitting diode therapy or placebo was applied from a flexible light-emitting diode array (λ = 850 nm, total energy = 75 J, t = 15 seconds) to both quadriceps femoris muscles of each twin immediately after each strength training session (3 times/wk for 12 weeks) consisting of leg press and leg extension exercises with load of 80% and 50% of the 1-repetition maximum test, respectively. Muscle biopsies, magnetic resonance imaging, maximal load, and fatigue resistance tests were conducted before and after the training program to assess gene expression, muscle hypertrophy and performance, respectively. Creatine kinase levels in blood and visual analog scale assessed muscle damage and delayed-onset muscle soreness, respectively, during the training program.
Compared with placebo, LEDT increased the maximal load in exercise and reduced fatigue, creatine kinase, and visual analog scale. Gene expression analyses showed decreases in markers of inflammation (interleukin 1β) and muscle atrophy (myostatin) with LEDT. Protein synthesis (mammalian target of rapamycin) and oxidative stress defense (SOD2 [mitochondrial superoxide dismutase]) were up-regulated with LEDT, together with increases in thigh muscle hypertrophy.
Light-emitting diode therapy can be useful to reduce muscle damage, pain, and atrophy, as well as to increase muscle mass, recovery, and athletic performance in rehabilitation programs and sports medicine.

暂无摘要。

In this study we show that selection based on progeny testing is able to induce a rapid change in allele frequency, even when a fairly broad and balanced breeding goal is applied. The myostatin 3\'-UTR mutation (c.*1232G>A) previously found to affect muscularity in Texel sheep is also present in the Norwegian White Sheep population. By genotyping the rams used for artificial insemination (born in1977-2006), a rapid increase in the c.*1232G>A allele frequency was observed, from 0.31 in 1990 to 0.82 in 2006. The major increase was observed after BLUP-based breeding values and the EUROP classification system for carcass quality was implemented in 1991 and 1996, respectively. The MSTN frameshift mutation c.960delG, recently identified in this population, did not show a similar increase in allele frequency during the same period, in spite that it has a strong desirable effect on meat and fat traits. The results also illustrate that unwanted side effects can rapidly be introduced into a population using an efficient breeding scheme. A system for monitoring changes in phenotypic traits additional to those under selection is therefore recommended to identify possible side effects at an early stage.

Loss of skeletal muscle mass is a poorly understood complication of end-stage liver disease (ESLD). Based on recent stem cell literature, we hypothesized that the potent negative regulator of muscle mass, myostatin, could play a role in the muscle loss associated with ESLD. In this preliminary investigation, we measured myostatin levels in patients undergoing liver transplant evaluation, using a novel enzyme-linked immunosensitivity assay. Myostatin levels were significantly elevated in patients with ESLD compared with healthy controls. These data suggest that myostatin deserves further investigation as a target for therapies designed to preserve muscle mass in patients with ESLD.