History dependence of the electromyogram: Implications for isometric steady-state EMG parameters following a lengthening or shortening contraction

Residual force enhancement (RFE) and force depression (FD) refer to an increased or decreased force following an active lengthening or shortening contraction, respectively, relative to the isometric force produced at the same activation level and muscle length. Our intent was to determine if EMG characteristics differed in the RFE or FD states compared with a purely isometric reference contraction for maximal and submaximal voluntary activation of the adductor pollicis muscle. Quantifying these alterations to EMG in history-dependent states allows for more accurate modeling approaches for movement control in the future. For maximal voluntary contractions (MVC), RFE was 6–15% (P < 0.001) and FD was 12–19% (P < 0.001). The median frequency of the EMG was not different between RFE, FD and isometric reference contractions for the 100% and 40% MVC intensities (P > 0.05). However, root mean square EMG (EMG_RMS) amplitude for the submaximal contractions was higher in the FD and lower in the RFE state, respectively (P < 0.05). For maximal contractions, EMG_RMS was lower for the FD state but was the same for the RFE state compared to the isometric reference contractions (P > 0.05). Neuromuscular efficiency (NME; force/EMG) was lower in the force depressed state and higher in the force enhanced state (P < 0.05) compared to the isometric reference contractions. EMG spectral properties were not altered between the force-enhanced and depressed states relative to the isometric reference contractions, while EMG amplitude measures were.     

Polymorphisms of tumor-related genes IL-10, PSCA,MTRR and NOC3L are associated with the risk of gastric cancer in the Chinese Han population

BackgroundGastric cancer is the fourth most common cancer in the world. Environmental and genetic factors both play critical roles in the etiology of gastric cancer. Hundreds of SNPs have been identified to have association with the risk of gastric cancer in many races. In this study, 25 SNPs in genes for IL-10, IL-1B, MTRR, TNF-а, PSCA, PLCE1 and NOC3L were analyzed to further evaluate their associations with gastric cancer susceptibility in the Chinese Han population.MethodsTwo hundred and seventy nine gastric cancer patients and 296 healthy controls were recruited in this study. SNP genotyping was conducted using Sequenom MassARRAY RS1000. Data management and statistical analyses were conducted by Sequenom Typer 4.0 Software and Pearson's χ² test.ResultsOne protective allele and three risk alleles for gastric cancer patients were found in this study. The allele “G” of rs1801394 in MTRR showed an association with a decreased risk of gastric cancer: odds ratio (OR) = 0.74, 95% confidence interval (95% CI) = 0.57–0.97, P = 0.030 in the additive model; OR = 0.495, 95% CI = 0.26–0.95, P = 0.034 in the recessive model. The other three SNPs, the allele “C” of rs1800871 in IL10 (OR = 1.33, 95% CI = 1.04–1.90; P = 0.026 in the additive model; OR = 1.46, 95% CI = 1.04–2.06; P = 0.030 in the recessive model), the allele “A” of rs2976391 in PSCA (OR = 1.30, 95% CI = 1.01–1.66; P = 0.041 in the additive model and OR = 1.48, 95% CI = 1.04–2.11, P = 0.028 in the recessive model), and the allele “G” of rs17109928 in NOC3L gene (OR = 1.34, 95% CI = 1.01–1.78; P = 0.042 by additive model analysis; OR = 1.47, 95% CI = 1.04–2.07, P = 0.028 by dominant model analysis), showed an association with an increased risk of gastric cancer.ConclusionsThese results indicate the importance of four gastric cancer susceptibility polymorphisms of IL-10, NOC3L, PSCA and MTRR in the Chinese Han population, which could be used in the determination of gastric cancer risk in clinical practice.     

Innervation zone shift at different levels of isometric contraction in the biceps brachii muscle

Experiments were carried out to examine whether innervation zone (IZ) location remains stable at different levels of isometric contraction in the biceps brachii muscle (BB), and to determine how the proximity of the IZ affects common surface electromyography (sEMG) parameters. Twelve subjects performed maximal (MVC) and submaximal voluntary isometric contractions at 10%, 20%, 30%, 40%, 50% and 75% of MVC. sEMG signals were recorded with a 13 rows × 5 columns grid of electrodes from the short head of BB. The IZ shifted in the proximal direction by up to 2.4 cm, depending upon the subject and electrode column. The mean shift of all the columns was 0.6 ± 0.4 cm (10% vs. 100% MVC, P < 0.001). This shift biased the average values of mean frequency (+21.8 ± 9.9 Hz, P < 0.001), root mean square (?0.16 ± 0.15 mV, P < 0.05) and conduction velocity (?1.15 ± 0.93 m/s, P < 0.01) in the channels immediately proximal to the IZ. The shift in IZ could be explained by shortening of the muscle fibers, and thus lengthening of the (distal) tendon due to increasing force. These results underline the importance of individual investigation of IZ locations before the placement of sEMG electrodes, even in isometric contractions.     

Ultrasonographic quantification of architectural response in tibialis anterior to neuromuscular electrical stimulation

While muscle contraction in voluntary efforts has been widely investigated, little is known about contraction during neuromuscular electrical stimulation (NMES). The aim of this study was to quantify in vivo muscle architecture of agonist and antagonist muscles at the ankle joint during NMES. Muscle fascicle lengths and pennation angles of the tibialis anterior (TA) and lateral gastrocnemius muscles were assessed via ultrasonography in 8 healthy young males. Measures were obtained during maximal NMES and torque-matched voluntary dorsiflexion contractions. In the TA, NMES induced a shorter fascicle length (67.2 ± 8.1 mm vs 74.6 ± 11.4 mm; p = 0.04) and a greater pennation angle (11.0 ± 2.4° vs 9.3 ± 2.5°; p = 0.03) compared with voluntary torque-matched dorsiflexion contractions. Architectural responses in the antagonist lateral gastrocnemius muscle did not significantly differ from rest or between voluntary and electrically induced contractions (p > 0.05). Contraction of the antagonist muscle was not a contributing factor to a greater fascicle shortening and increased pennation angle in the TA during NMES. TA architectural response during NMES likely arose from the contribution of muscle synergists during voluntary contractions coupled with a potentially localized contractile activity under the stimulation electrodes during NMES induced contractions.     

In vivo moment generation and architecture of the human plantar flexors after different shortening–stretch cycles velocities

The purpose of this study was to examine the moment generation of the human plantar flexors and the architecture of the gastrocnemius medialis muscle during and after shortening–stretch cycles in vivo. Fourteen male subjects (30 ± 7 years, 177 ± 7 cm, 80 ± 9 kg) performed a series of electro-stimulated shortening–stretch plantar flexion contractions. The shortening–stretch cycles were performed at three constant angular velocities (25°/s, 50°/s, 100°/s), two amplitudes (15° and 25° ankle angle changes) and at two different stimulation frequencies (30 Hz and 85 Hz). The resultant ankle joint moments were calculated through inverse dynamics. Pennation angle and fascicle length of the m. gastrocnemius medialis at rest and during contractions were measured using ultrasonography. The corresponding ankle moments, kinematics and changes in muscle architecture were analysed at seven time intervals. A three-way analysis of variance (amplitude × velocity × stimulation frequency) and post-hoc test with Bonferroni correction were used to check the amplitude, velocity and stimulation level related effects on moment enhancement (α = 0.05). The results show an ankle joint moment enhancement after shortening–stretch cycles influenced by muscle architectural changes. We found 2–3% isometric ankle joint moment enhancement at steady state, 1.5–2.0 s after the shortening–stretch cycle. However, the observed alteration in muscle architecture after the imposed perturbation, could lead to an underestimation (1–3%) of joint moment enhancement due to the force–length relationship of the triceps surae. Furthermore, the enhancement observed was independent of the shortening–stretch amplitude, velocity and stimulation frequency.     

Subtype analysis of Blastocystis sp. isolates from human and canine hosts in an urban community in the Philippines

Blastocystis sp. is a common gut-dwelling protist of both humans and animals. A cross-sectional survey among humans and their dogs was conducted to determine the prevalence of Blastocystis infection and to characterize the subtype (ST) distribution in an urban community in the Philippines. Fecal specimens from 1,271 humans and 145 dogs were collected and inoculated in diphasic culture medium. Prevalence of Blastocystis by culture was 13.0% (95% CI = 11.2–15.0) and 14.5% (95% CI = 9.6–21.2) for humans and dogs, respectively. A total of 168 culture isolates were genotyped using polymerase chain reaction (PCR) with seven pairs of ST-specific sequence-tagged-site (STS) primers. In humans, the ST present in this study were ST1 with 22.6% (95% CI = 17.2–29.0), ST2 with 3.1% (95% CI = 1.3–6.7), ST3 with 41.4% (95% CI = 34.9–48.6), ST4 with 14.8% (95% CI = 10.5–20.6), ST5 with 4.1% (95% CI = 2.0–8.0), and unknown ST with 13.9% (95% CI = 9.6–19.4). In dogs, the ST present in this study were ST1 with 4.3% (95% CI = 0.0–29.0), ST2 with 8.7% (95% CI = 1.3–28.0), ST3 with 17.4% (95% CI = 6.4–37.7), ST4 with 13.0% (95% CI = 3.7–33.0), ST5 with 13.0% (95% CI = 3.7–33.0), and unknown ST with 47.8% (95% CI = 29.2–67.0). This is the first study that reported Blastocystis ST4 in human and canine hosts in the Philippines.     

Increased serum 2-oxoglutarate associated with high myocardial energy expenditure and poor prognosis in chronic heart failure patients

Myocardial energy expenditure (MEE) and 2-oxoglutarate are elevated in chronic heart failure (CHF) patients compared with healthy controls. To explore whether 2-oxoglutarate could reflect the levels of MEE and predict the prognosis of CHF, 219 CHF patients and 66 healthy controls were enrolled. 2-Oxoglutarate was assayed with Liquid Chromatography–Mass Spectrometry/Mass Spectrometry (LC/MS/MS). CHF patients were divided into 4 groups according to interquartile range of MEE and followed for death or recurrent hospital admission due to CHF for the mean follow-up time 6.64 ± 0.16 months. 2-Oxoglutarate was increased in CHF patients compared with controls (P < 0.01) and correlated with estimated glomerular filtration rate (r = 0.142, P = 0.036), age (r = − 0.269, P < 0.01) and MEE levels (r = 0.307, P < 0.01) in a multiple linear correlation analysis in CHF patients. Furthermore, 2-oxoglutarate (OR = 3.470, 95% CI = 1.557 to 7.730, P = 0.002), N-terminal pro-B-type natriuretic peptide (OR = 4.013, 95% CI = 1.553 to 10.365, P = 0.004), age (OR = 1.611, 95% CI = 1.136 to 2.283, P = 0.007) and left ventricular ejection fraction (OR = 7.272, 95% CI = 3.110 to 17.000, P < 0.001) were independently associated with MEE on multiple logistic regression analysis. Kaplan–Meier event curves showed that high 2-oxoglutarate levels were associated with adverse outcomes (Log Rank, Chi² = 4.026, P = 0.045). This study showed that serum 2-oxoglutarate is associated with MEE levels, which can be used as potential biomarkers for MEE, and it can reflect the clinical severity and short-term outcome of CHF.     

Genetic polymorphisms in AURKA,BRCA1, CCNE1 and CDK2 are associated with ovarian cancer susceptibility among Chinese Han women

IntroductionCentrosome aberrations and cell-cycle deregulation have important implications for ovarian cancer development. The AURKA, BRCA1, CCNE1 and CDK2 genes play pivotal roles in centrosome duplication and cell-cycle regulation.MethodsUsing a haplotype-based analysis, this study aimed to investigate whether genetic polymorphisms in these four genes may contribute to ovarian cancer susceptibility. A total of 22 single nucleotide polymorphisms (SNPs) in these four genes were genotyped in 287 cases of ovarian serous cystadenocarcinomas and 618 age-matched cancer-free controls from the Chinese Han population, and then haplotype blocks were reconstructed according to our genotyping data and linkage disequilibrium (LD) status of these SNPs.ResultsFor AURKA, we found that haplotype GA [rs6064391 (T→G) + rs911162 (G→A)] was strongly associated with decreased ovarian cancer risk (adjusted OR = 0.31, 95% CI = 0.15–0.63, P = 0.0012). For BRCA1, we found that haplotype CGTAG was associated with decreased ovarian cancer risk (adjusted OR = 0.64, 95% CI = 0.41–0.98, P = 0.0417). Moreover, women harboring homozygous GA/CGTAG haplotypes showed the lowest risk (OR = 0.12, 95% CI = 0.02–0.94, P = 0.0438). In CCNE1, the SNPs rs3218035 and rs3218042 were significantly associated with increased ovarian cancer risk (rs3218035: adjusted OR = 5.20, 95% CI = 1.85–14.52, P = 0.0017; rs3218042: adjusted OR = 4.98, 95% CI = 1.75–14.19, P = 0.0027). For CDK2, no significant association was found.ConclusionsThis study indicates that genetic polymorphisms of AURKA, BRCA1 and CCNE1 may affect ovarian cancer susceptibility in Chinese Han women.     

Asociación de la fuerza muscular con marcadores tempranos de riesgo cardiovascular en adultos sedentarios

ObjectiveTo assess the association between muscle strength and early cardiovascular risk (CVR) markers in sedentary adults.Materials and methodsA total of 176 sedentary subjects aged 18-30 years were enrolled. Body mass index and fat percentage were calculated, and waist circumference, grip strength by dynamometry, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and maximal oxygen uptake by VO_2max were measured as CVR markers. A multivariate logistic regression analysis was used to assess associations between muscle strength and CVR markers.ResultsInverse correlations were found between muscle strength and adiposity (r = -.317; P = .001), waist circumference (r = -.309; P = .001), systolic blood pressure (r = -.401; P = .001), and mean arterial pressure (r = -.256; P = .001). Subjects with lower levels of muscle strength had a 5.79-fold (95% CI 1.57 to 9.34; P = .008) risk of having higher adiposity levels (≥ 25%) and a 9.67-fold (95% CI = 3.86 to 19.22; P < .001) risk of having lower physical capacity values for VO_2max (≤ 31.5 mL/kg/min^-1).ConclusionsIn sedentary adults, muscle strength is associated to early manifestations of CVR. It is suggested that muscle strength testing is added to routine measurement of VO_2max and traditional risk factors for prevention and treatment of cardiovascular risk.     

Prediction of all-cause mortality with copeptin in cardio-cerebrovascular patients: A meta-analysis of prospective studies

BackgroundMeasurement of the biomarker copeptin may help identify disease severity and risk of mortality for a various diseases. This study sought to determine the relationship between copeptin and all-cause mortality of patients with cardio-cerebrovascular disease.MethodsDatabase of Medline and Web of Science were searched for studies with data involving the baseline copeptin levels and subsequent all-cause mortality outcomes. The pooled HRs of all-cause mortality were calculated and presented with 95%CIs. Subgroup analysis and sensitivity analysis were conducted to explore the possible sources of heterogeneity.ResultsData from 14,395 participants were derived from 28 prospective studies. Higher copeptin significantly increased the risk of all-cause mortality (per unit copeptin: HR = 1.020, 95%CI = 1.004–1.036; log unit copeptin: HR = 2.884, 95%CI = 1.844–4.512; categorical copeptin: HR = 3.371, 95%CI = 2.077–5.472). Subgroup analysis indicated that the risk of all-cause death was higher in cerebrovascular patients (per unit copeptin: HR = 2.537, 95%CI = 0.956–6.731; log unit copeptin: HR = 3.419, 95%CI = 2.391–4.888) than cardiovascular patients (per unit copeptin: HR = 1.011, 95%CI = 1.002–1.020; log unit copeptin: HR = 2.009, 95%CI = 1.119–3.608).ConclusionCopeptin is associated with all-cause mortality of patients with cardiovascular and cerebrovascular disease. Our study suggests that copeptin seems to be a promising novel biomarker for prediction of mortality in cardio-cerebrovascular patients, especially for cerebrovascular patients.     

Patients with chronic,but not episodic,migraine display altered activity of their neck extensor muscles

The current study aimed to investigate differences in activity of neck flexor and extensor muscles in women with migraine considering the chronicity of their condition. Thirty-one subjects with episodic migraine, 21 with chronic migraine and 31 healthy controls participated. Surface electromyography signals were recorded bilaterally from the sternocleidomastoid, anterior scalene, splenius capitis and upper trapezius muscles as subjects performed 5 stages of cranio-cervical flexion (CCF), representing a progressive increase in range of CCF motion. Comparison of normalized root-mean-square among groups was conducted with 3 × 5 ANCOVA with task level as the within-subject variable, group as the between-subject variable, and the presence of neck pain and disability as co-variates. The group with chronic migraine exhibited increased activity of their extensor muscles compared to the control and episodic migraine groups (splenius capitis: F = 3.149, P = 0.045; upper trapezius: F = 3.369, P = 0.041). No significant between-group differences were found for the superficial neck flexors (sternocleidomastoid: F = 1.161, P = 0.320; anterior scalene: F = 0.135, P = 0.874). In conclusion, women with chronic migraine exhibit increased activity of their superficial neck extensor muscles when acting as antagonists during low-load isometric CCF contractions in comparison to non-headache subjects.     

Promoter polymorphism (−590, T/C) of interleukin 4 (IL4) gene is associated with rheumatoid arthritis: An updated meta-analysis

Rheumatoid arthritis (RA) is a chronic disease. It causes chronic inflammation of the joint. Recent studies suggested that interleukin 4 (IL4) contributes to susceptibility and severity of rheumatoid arthritis (RA). Especially, it was reported that promoter polymorphism (−590, T/C) of IL4 gene has been associated with susceptibility of RA. The aim of present study was to investigate whether the promoter polymorphism (−590, T/C) of IL4 gene is associated with the susceptibility of RA using meta-analysis. And in order to perform meta-analysis, comprehensive meta analysis program was used. Genetic models (co-dominant, dominant, recessive, and allele) were used to determine odds ratios (ORs), 95% confidence intervals (CIs), and P values. Nine case-control studies with case and control design were included in this meta-analysis. Overall, meta-analysis revealed a strong association with susceptibility of RA [OR = 1.303, 95% CI = 1.093–1.554, P = 0.003 in allele model (C vs. T); OR = 1.247, 95% CI = 1.054–1.474, P = 0.010 in dominant model (CC vs. CT + TT); OR = 2.148, 95% CI = 1.263–3.651, P = 0.005 in recessive model (CC + CT vs. TT)]. Our data demonstrated that promoter polymorphism (−590, T/C) of IL4 gene may be contributed to susceptibility of RA. However, more studies with a larger sample size are needed to provide more precise evidence.     

The minimum number of contractions required to examine the EMG amplitude versus isometric force relationship for the vastus lateralis and vastus medialis

Studies have demonstrated that the electromyographic (EMG) amplitude versus submaximal isometric force relationship is relatively linear. The purpose of this investigation was to determine the minimum number of contractions required to study this relationship. Eighteen men (mean age = 23 years) performed isometric contractions of the leg extensors at 10–90% of the maximum voluntary contraction (MVC) in 10% increments while surface EMG signals were detected from the vastus lateralis and vastus medialis. Linear regression was used to determine the coefficient of determination, slope coefficient, and y-intercept for each muscle and force combination with successively higher levels included in the model (i.e., 10–30%, … 10–90% MVC). For the slope coefficients, there was a main effect for force combination (P < .001). The pairwise comparisons showed there was no difference from 10–60% through 10–90% MVC. For the y-intercepts, there were main effects for both muscle (vastus lateralis [4.3 μV RMS] > vastus medialis [−3.7 μV RMS]; P = .034) and force combination (P < .001), with similar values shown from 10–50% through 10–90% MVC. The linearity of the absolute EMG amplitude versus isometric force relationship for the vastus lateralis and vastus medialis suggests that investigators may exclude high force contractions from their testing protocol.     

Surveillance,Epidemiology, and End Results-based analysis of the impact of preoperative or postoperative radiotherapy on survival outcomes for T3N0 rectal cancer

Purpose: Preoperative chemoradiation has been established as standard of care for T3/T4 node-positive rectal cancer. Recent work, however, has called into question the overall benefit of radiation for tumors with lower risk characteristics, particularly T3N0 rectal cancers. We retrospectively analyzed T3N0 rectal cancer patients and examined how outcomes differed according to the sequence of treatment received. Methods: The Surveillance, Epidemiology, and End Results (SEER) database was used to analyze T3N0 rectal cancer cases diagnosed between 1998 and 2008. Treatment consisted of surgery alone (No RT), preoperative radiation followed by surgery (Neo-Adjuvant RT), or surgery followed by postoperative radiation (Adjuvant RT). Demographic and tumor characteristics of the three groups were compared using t-tests for the comparison of means. Survival information from the SEER database was utilized to estimate cause-specific survival (CSS) and to generate Kaplan–Meier survival curves. Multivariate analysis (MVA) of features associated with outcomes was conducted using Cox proportional hazards regression models with Adjuvant RT, Neo-Adjuvant RT, No RT, histological grade, tumor size, year of diagnosis, and demographic characteristics as covariates. Results: 10-Year CSS estimates were 66.1% (95% CI 62.3–69.6%; P = 0.02), 73.5% (95% CI 68.9–77.5%; P = 0.02), and 76.1% (95% CI 72.4–79.4%; P = 0.02), for No RT, Neo-Adjuvant RT, and Adjuvant RT, respectively. On MVA, Adjuvant RT (HR = 0.688; 95% CI, 0.578–0.819; P < 0.001) was associated with significantly decreased risk for cancer death. By contrast, Neo-Adjuvant RT was not significantly associated with improved cancer survival (HR = 0.863; 95% CI, 0.715–1.043; P = 0.127). Conclusion: Adjuvant RT was associated with significantly higher CSS when compared with surgery alone, while the benefit of Neo-Adjuvant RT was not significant. This indicates that surgery followed by Adjuvant RT may still be an important treatment plan for T3N0 rectal cancer with potentially significant survival advantages over other treatment sequences.     

Measuring voluntary quadriceps activation: Effect of visual feedback and stimulus delivery

Introduction: Quadriceps voluntary activation, assessed via the superimposed burst technique, has been extensively studied in a variety of populations as a measure of quadriceps function. However, a variety of stimulus delivery techniques have been employed, which may influence the level of voluntary activation as calculated via the central activation ratio (CAR). The purpose was to determine the effect of visual feedback, stimulus delivery, and perceived discomfort on maximal voluntary isometric contraction (MVIC) peak torque and the CAR. Methods: Quadriceps CAR was assessed in 14 individuals on two days using three stimulus delivery methods; (1) manual without visual feedback, (2) manual with visual feedback, and (3) automated with visual feedback. Results: MVIC peak torque and the CAR were not different between the automated with visual feedback (MVIC = 3.25, SE = 0.14 N m/kg; CAR = 88.63, SE = 1.75%) and manual with visual feedback (MVIC = 3.26, SE = 0.13 N m/kg, P = 0.859; CAR = 89.06, SE = 1.70%, P = 0.39) stimulus delivery methods. MVIC (2.99, SE = 0.12 N m/kg) and CAR (85.32, SE = 2.10%) were significantly lower using manual without visual feedback compared to manual with visual feedback and automated with visual feedback (CAR P < 0.001; MVIC P < 0.001). Perceived discomfort was lower in the second session (P < 0.05). Conclusion: Utilizing visual feedback ensures participant MVIC, and may provide a more accurate assessment of quadriceps voluntary activation.     

Low serum interleukin-6 levels as a predictive marker of recurrence in patients with hepatitis B virus related hepatocellular carcinoma who underwent curative treatment

BackgroundWe aimed to investigate the use of novel serum biomarkers for predicting the recurrence and survival of patients with hepatitis B virus (HBV)-related early hepatocellular carcinoma (HCC) after hepatic resection or radiofrequency ablation (RFA).MethodsOne hundred and five patients with HBV-related HCC, who fulfilled the Milan criteria without vascular invasion and underwent hepatic resection or RFA, were followed-up for a median duration of 52 months. Pretreatment serum concentrations of 16 cytokines including interleukin-6 (IL-6) were measured by using a Luminex 200 system. The measured serum cytokines and several clinical factors were analyzed retrospectively.ResultsUnivariate analysis showed that patients with lower pretreatment serum levels of IL-10, IL-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α had significantly shorter disease-free survival (DFS) than those with higher levels. Multivariate analysis revealed that a low serum IL-6 level (⩽33.00 pg/mL; hazard ratio [HR] = 5.39; 95% confidence interval [CI] = 1.27–22.93; P = 0.022), low platelet count (<100 × 10⁹/L; HR = 2.23; 95% CI = 1.28–3.89; P = 0.005), and low serum albumin level (⩽3.5 g/L; HR = 2.26; 95% CI = 1.28–3.97; P = 0.005) had a negative prognostic impact on DFS. In the analysis for overall survival, a low serum platelet level (<100 × 10⁹/L; HR = 2.80; 95% CI = 1.31–5.99; P = 0.008) and multiple tumor (⩾2; HR = 4.05; 95% CI = 1.56–10.48; P = 0.004) showed a negative prognostic impact on the overall survival.ConclusionA low serum IL-6 level is, in addition to low platelet count and low serum albumin level, an independent prognostic factor for DFS in patients with HBV-related early HCC who underwent hepatic resection or RFA with curative intention.     

Acute severe male hypo-testosteronemia affects central motor command in humans

Purpose: To indirectly evaluate the effect of androgens on neuromuscular system in humans we analyzed if an induced short-term hypogonadal state (serum total testosterone-TT < 2.3 ng/ml) may affect central drive to skeletal muscle and/or muscle neuro-mechanical performance. Methods: We compared voluntary and electrically evoked muscle sEMG signals from biceps brachii in nine hypogonadal male volunteers (Hypo) and in ten healthy controls (Cont). Serum TT and dihydrotestosterone (DHT) were assayed. Results: With respect to Hypo, Cont exhibited significantly higher median frequency content (MDF) at any angular velocity; normalized MDF [95.9% (SD = 23.3) vs 73.8% (SD = 9.3)]; muscle fiber conduction velocity (CV) from lowest to highest angular velocities; initial MDF at fatigue test [91.78 Hz (SD = 22.03) vs 70.94 Hz (SD = 11.06)] as well as was the normalized slope [−0.64 (SD = 0.14 vs −0.5 (SD = 0.11)]. In the non-fatigued state, Hypo showed a slower single twitches time to peak (TTP). In Cont, half relaxation time (HRT) decreased after fatigue while increased in Hypo (p < 0.05 between groups). A significant correlation between both TT and dihydrotestosterone with MDF and CV was found during voluntary contractions only. Conclusions: A brief exposure to very low serum TT concentration in males seem to determine a reduced excitability of the NM system which, in turn, would favor a predominant recruitment of slow twitch MUs.     

A comparison of surface and fine wire EMG recordings of gluteus medius during selected maximum isometric voluntary contractions of the hip

Electromyographic (EMG) studies into gluteus medius (GMed) typically involve surface EMG electrodes. Previous comparisons of surface and fine wire electrode recordings in other muscles during high load isometric tasks suggest that recordings between electrodes are comparable when the muscle is contracting at a high intensity, however, surface electrodes record additional activity when the muscle is contracting at a low intensity. The purpose of this study was to compare surface and fine wire recordings of GMed at high and low intensities of muscle contractions, under high load conditions (maximum voluntary isometric contractions, MVICs). Mann–Whitney U tests compared median electrode recordings during three MVIC hip actions; abduction, internal rotation and external rotation, in nine healthy adults. There were no significant differences between electrode recordings in positions that evoked a high intensity contraction (internal rotation and abduction, fine wire activity >77% MVIC; effect size, ES < 0.42; p > 0.277). During external rotation, the intensity of muscle activity was low (4.2% MVIC), and surface electrodes recorded additional myoelectric activity (ES = 0.67, p = 0.002). At low levels of muscle activity during high load isometric tasks, the use of surface electrodes may result in additional myoelectric recordings of GMed, potentially reflective of cross-talk from surrounding muscles.     

Perfil clínico y mortalidad a 90 días de los pacientes centenarios atendidos en servicios de urgencias hospitalarios

ObjectivesTo determine the clinical profile and to develop a model to predict 90-day mortality in centenarian patients attended in emergency departments (ED).MethodologyThis was an observational, retrospective, multicentre cohort study including patients > 99 years attended in 5 ED in the Community of Madrid from January to December 2012. Demographic variables were recorded, as well as, comorbidities, cognitive, functional, social basal status, geriatric syndromes, acute episode, and hospital and social resources use, and 90-day mortality.ResultsThe study included 209 patients aged 101 years (SD 1.7) of whom 161 (77.0%) were female. Sixty four (32.5%) had severe comorbidity (Charlson index ≥ 3), 101 (49.8%) on multiple medication, 100 (52.6%) had cognitive impairment, 82 (42.3%) had severe functional dependence, 85 (40.7%) were institutionalised, and 190 (94.5%) had a geriatric syndrome. Dyspnoea (26.8%), followed by falls (12.4%) were the most common causes of attendance. One hundred and eighteen (56.5%) were admitted, and 58 out of 174 (33.3%) died in the first 90 days. The model to predict 90-day overall mortality included male sex (OR 2.42 95% CI = 0.97-6.04; P = .059), emergency care in the previous 3 months (OR 4.08 95% CI = 1.26-13.16; P = .019) and the hospitalization by index event (OR 8.63 95% CI = 3.25-22.9; P < .001) and this model had an area under ROC curve of 0.776 (95% CI = 0.70-0.85; P < .001).ConclusionsCentenarian patients attended in ED had a significant frailty and one in three cases died in the first 90 days after being attended, and this was associated with male sex, emergency care in the previous 3 months, and hospitalisation.