Sarcopenia, a newly recognized geriatric syndrome, is characterized by age-related decline of skeletal muscle plus low muscle strength and/or physical performance. Previous studies have confirmed the ...association of sarcopenia and adverse health outcomes, such as falls, disability, hospital admission, long term care placement, poorer quality of life, and mortality, which denotes the importance of sarcopenia in the health care for older people. Despite the clinical significance of sarcopenia, the operational definition of sarcopenia and standardized intervention programs are still lacking. It is generally agreed by the different working groups for sarcopenia in the world that sarcopenia should be defined through a combined approach of muscle mass and muscle quality, however, selecting appropriate diagnostic cutoff values for all the measurements in Asian populations is challenging. Asia is a rapidly aging region with a huge population, so the impact of sarcopenia to this region is estimated to be huge as well. Asian Working Group for Sarcopenia (AWGS) aimed to promote sarcopenia research in Asia, and we collected the best available evidences of sarcopenia researches from Asian countries to establish the consensus for sarcopenia diagnosis. AWGS has agreed with the previous reports that sarcopenia should be described as low muscle mass plus low muscle strength and/or low physical performance, and we also recommend outcome indicators for further researches, as well as the conditions that sarcopenia should be assessed. In addition to sarcopenia screening for community-dwelling older people, AWGS recommends sarcopenia assessment in certain clinical conditions and healthcare settings to facilitate implementing sarcopenia in clinical practice. Moreover, we also recommend cutoff values for muscle mass measurements (7.0 kg/m(2) for men and 5.4 kg/m(2) for women by using dual X-ray absorptiometry, and 7.0 kg/m(2) for men and 5.7 kg/m(2) for women by using bioimpedance analysis), handgrip strength (<26 kg for men and <18 kg for women), and usual gait speed (<0.8 m/s). However, a number of challenges remained to be solved in the future. Asia is made up of a great number of ethnicities. The majority of currently available studies have been published from eastern Asia, therefore, more studies of sarcopenia in south, southeastern, and western Asia should be promoted. On the other hand, most Asian studies have been conducted in a cross-sectional design and few longitudinal studies have not necessarily collected the commonly used outcome indicators as other reports from Western countries. Nevertheless, the AWGS consensus report is believed to promote more Asian sarcopenia research, and most important of all, to focus on sarcopenia intervention studies and the implementation of sarcopenia in clinical practice to improve health care outcomes of older people in the communities and the healthcare settings in Asia.
Glioma is the most common type of malignant neoplasm in the central nervous system, with high incidence and mortality rate. MicroRNAs, as a class of small non-coding RNAs, play an important role in ...carcinogenesis and correlate with glioma diagnosis and prognosis. In this study, we investigated the microRNA-204 (miR-204) concentration in glioma tissues and its relation to the expression of ezrin and bcl-2 mRNA, as well as its potential predictive and prognostic values in glioma. The concentrations of miR-204 were significantly lower in glioma tissues than in non-tumor brain tissues and also were lower in high-grade than in low-grade gliomas (World Health Organization WHO grades III and IV vs grades I and II). The miR-204 concentration was inversely correlated with the ezrin and bcl-2 concentrations. The miR-204 concentration was classified as high or low according to the median value, and low miR-204 correlated with higher WHO grade, larger tumor, and worse Karnofsky performance score (KPS). Kaplan-Meier survival analysis demonstrated that patients with low miR-204 expression had shorter progression-free survival (PFS) and overall survival (OS) than patients with high miR-204 expression. In addition, univariate and multivariate analyses showed that miR-204 expression was an independent prognostic feature of OS and PFS. In conclusion, our study indicates that miR-204 is downregulated in glioma and may be a biomarker of poor prognosis in patients with this cancer.
Sympathetic nerve activity is important to cardiac arrhythmogenesis.
The purpose of this study was to develop a method for simultaneous noninvasive recording of skin sympathetic nerve activity (SKNA) ...and electrocardiogram (ECG) using conventional ECG electrodes. This method (neuECG) can be used to adequately estimate sympathetic tone.
We recorded neuECG signals from the skin of 56 human subjects. The signals were low-pass filtered to show the ECG and high-pass filtered to show nerve activity. Protocol 1 included 12 healthy volunteers who underwent cold water pressor test and Valsalva maneuver. Protocol 2 included 19 inpatients with epilepsy but without known heart diseases monitored for 24 hours. Protocol 3 included 22 patients admitted with electrical storm and monitored for 39.0 ± 28.2 hours. Protocol 4 included 3 patients who underwent bilateral stellate ganglion blockade with lidocaine injection.
In patients without heart diseases, spontaneous nerve discharges were frequently observed at baseline and were associated with heart rate acceleration. SKNA recorded from chest leads (V
-V
) during cold water pressor test and Valsalva maneuver (protocol 1) was invariably higher than during baseline and recovery periods (P < .001). In protocol 2, the average SKNA correlated with heart rate acceleration (r = 0.73 ± 0.14, P < .05) and shortening of QT interval (P < .001). Among 146 spontaneous ventricular tachycardia episodes recorded in 9 patients of protocol 3, 106 episodes (73%) were preceded by SKNA within 30 seconds of onset. Protocol 4 showed that bilateral stellate ganglia blockade by lidocaine inhibited SKNA.
SKNA is detectable using conventional ECG electrodes in humans and may be useful in estimating sympathetic tone.
Objectives The purpose of this study was to evaluate the changes of left stellate ganglionic nerve activity (SGNA) and left thoracic vagal nerve activity (VNA) after acute myocardial infarction (MI). ...Background Whether MI results in remodeling of extracardiac nerve activity remains unclear. Methods We implanted radiotransmitters to record the SGNA, VNA, and electrocardiogram in 9 ambulatory dogs. After baseline monitoring, MI was created by 1-h balloon occlusion of the coronary arteries. The dogs were then continuously monitored for 2 months. Both stellate ganglia were stained for growth-associated protein 43 and synaptophysin. The stellate ganglia from 5 normal dogs were used as control. Results MI increased 24-h integrated SGNA from 7.44 ± 7.19 Ln(Vs)/day at baseline to 8.09 ± 7.75 Ln(Vs)/day after the MI (p < 0.05). The 24-h integrated VNA before and after the MI was 5.29 ± 5.04 Ln(Vs)/day and 5.58 ± 5.15 Ln(Vs)/day, respectively (p < 0.05). A significant 24-h circadian variation was noted for the SGNA (p < 0.05) but not the VNA. The SGNA/VNA ratio also showed significant circadian variation. The nerve densities from the left SG were 63,218 ± 34,719 μm2 /mm2 and 20,623 ± 4,926 μm2 /mm2 for growth-associated protein 43 (p < 0.05) and were 32,116 ± 8,190 μm2 /mm2 and 16,326 ± 4,679 μm2 /mm2 for synaptophysin (p < 0.05) in MI and control groups, respectively. The right SG also showed increased nerve density after MI (p < 0.05). Conclusions MI results in persistent increase in the synaptic density of bilateral stellate ganglia and is associated with increased SGNA and VNA. There is a circadian variation of the SGNA/VNA ratio. These data indicate significant remodeling of the extracardiac autonomic nerve activity and structures after MI.
To explore the effectiveness of suprascapular nerve block (SSNB) at different timing after administration compared with physical therapy, placebo, and intra-articular injections in patients with ...chronic shoulder pain.
Two electronic data sources, PubMed and Scopus, were mainly searched from the earliest record to September 2015.
Eleven randomized controlled trials that compared SSNB with physical therapy, placebo, and intra-articular injections were included, comprising 591 patients.
Patient demographics, regimens for SSNB and intra-articular injections, use of fluoroscopy or ultrasound guidance, conjunction with physical therapy, methods of randomization, and measurements of functional change and pain improvement were retrieved. The standardized mean differences (SMDs) of pain relief and functional improvement were calculated 1, 4, and 12 weeks after intervention.
Regarding pain relief, SSNB provided better pain relief for 12 weeks compared with physical therapy (SMD=.75; 95% confidence interval CI, .35-1.14) and placebo injections (SMD=.70; 95% CI, .40-1.00), but was not superior to intra-articular injections. Differences in patient populations and use of pulsed radiofrequency did not cause a significant variation in therapeutic efficacy, but guidance using ultrasound showed consistently better effectiveness than guidance using surface landmarks and fluoroscopy.
This meta-analysis demonstrated the superiority of SSNB to placebo and physical therapy and a similar efficacy of SSNB compared with intra-articular injection for treatment of chronic shoulder pain. Ultrasound was the most preferable guidance tool, and future studies are advised to integrate physical therapy in order to improve the long-term effectiveness of SSNB.
Objectives The authors sought to characterize the left atrial (LA) and pulmonary vein (PV) electrophysiological and hemodynamic features in obese patients with atrial fibrillation (AF). Background ...Obesity is associated with increased risk for AF. Methods A total of 63 consecutive patients with AF who had normal left ventricular (LV) ejection fraction and who underwent catheter ablation were studied. Atrial and PV electrophysiological studies were performed at the time of ablation with hemodynamic assessment by cardiac catheterization, and LA/LV structure and function by echocardiography. Patients were compared on the basis of body mass index (BMI): <25 kg/m2 (n = 19) and BMI ≥30 kg/m2 (n = 44). Results At a 600-ms pacing cycle length, obese patients had shorter effective refractory period (ERP) in the left atrium (251 ± 25 ms vs. 233 ± 32 ms, p = 0.04), and in the proximal (207 ± 33 ms vs. 248 ± 34 ms, p < 0.001) and distal (193 ± 33 ms vs. 248 ± 44 ms, p < 0.001) PV than normal BMI patients. Obese patients had higher mean LA pressure (15 ± 5 mm Hg vs. 10 ± 5 mm Hg, p < 0.001) and LA volume index (28 ± 12 ml/m2 vs. 21 ± 14 ml/m2 , p = 0.006), and lower LA strain (5.5 ± 3.1% vs. 8.8 ± 2.8%; p < 0.001) than normal BMI patients. Conclusions Increased LA pressure and volume, and shortened ERP in the left atrium and PV are potential factors facilitating and perpetuating AF in obese patients with AF.
Early afterdepolarizations (EADs) are an important cause of lethal ventricular arrhythmias in long QT syndromes and heart failure, but the mechanisms by which EADs at the cellular scale cause ...arrhythmias such as polymorphic ventricular tachycardia (PVT) and torsades de pointes (TdP) at the tissue scale are not well understood. Here we summarize recent progress in this area, discussing (1) the ionic basis of EADs, (2) evidence that deterministic chaos underlies the irregular behavior of EADs, (3) mechanisms by which chaotic EADs synchronize in large numbers of coupled cells in tissue to overcome source-sink mismatches, (4) how this synchronization process allows EADs to initiate triggers and generate mixed focal reentrant ventricular arrhythmias underlying PVT and TdP, and (5) therapeutic implications.
Skin sympathetic nerve activity (SKNA) is useful for estimating sympathetic tone in humans.
The purpose of this study was to test the hypotheses that (1) increased SKNA is associated with the onset ...and termination of paroxysmal atrial tachycardia (AT) and atrial fibrillation (AF) and (2) sinoatrial node response to SKNA is reduced in patients with more frequent AT or AF episodes.
SKNA and electrocardiogram were recorded in 11 patients (4 men and 7 women; average age 66 ± 10 years), including 3 patients with AT (11 ± 18 episodes per patient) and 8 patients with AF (24 ± 26 episodes per patient).
The average SKNA (aSKNA) 10 seconds before AT onset was 1.07 ± 0.10 μV and 10 seconds after termination was 1.27 ± 0.10 μV; both were significantly (P = .032 and P < .0001) higher than that during sinus rhythm (0.97 ± 0.09 μV). The aSKNA 10 seconds before AF onset was 1.34 ± 0.07 μV and 10 seconds after termination was 1.31 ± 0.07 μV; both were significantly (P < .0001) higher than that during sinus rhythm (1.04 ± 0.07 μV). The aSKNA before onset (P < .0001) and after termination (P = .0011) was higher in AF than in AT. The sinus rate correlated (P < .0001) with aSKNA in each patient (average r = 0.74; 95% confidence interval 0.65-0.84). The r value in each patient negatively correlated with the number of AT and AF episodes (r = -0.6493; 95% confidence interval -0.8990 to -0.08073; P = .0306).
Increased SKNA was observed both at the onset and termination of AT and AF. Patients with more frequent AT and AF episodes had a weak correlation between sinus rate and aSKNA, suggesting sinoatrial node remodeling by tachycardia.
Renal sympathetic denervation (RD) is a promising method of neuromodulation for the management of cardiac arrhythmia.
We tested the hypothesis that RD is antiarrhythmic in ambulatory dogs because it ...reduces the stellate ganglion nerve activity (SGNA) by remodeling the stellate ganglion (SG) and brain stem.
We implanted a radiotransmitter to record SGNA and electrocardiogram in 9 ambulatory dogs for 2 weeks, followed by a second surgery for RD and 2 months SGNA recording. Cell death was probed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay.
Integrated SGNA at baseline and 1 and 2 months after RD were 14.0 ± 4.0, 9.3 ± 2.8, and 9.6 ± 2.0 μV, respectively (P = .042). The SG from RD but not normal control dogs (n = 5) showed confluent damage. An average of 41% ± 10% and 40% ± 16% of ganglion cells in the left and right SG, respectively, were TUNEL positive in RD dogs compared with 0% in controls dogs (P = .005 for both). The left and right SG from RD dogs had more tyrosine hydroxylase-negative ganglion cells than did the left SG of control dogs (P = .028 and P = .047, respectively). Extensive TUNEL-positive neurons and glial cells were also noted in the medulla, associated with strongly positive glial fibrillary acidic protein staining. The distribution was heterogeneous, with more cell death in the medial than lateral aspects of the medulla.
Bilateral RD caused significant central and peripheral sympathetic nerve remodeling and reduced SGNA in ambulatory dogs. These findings may in part explain the antiarrhythmic effects of RD.
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