Impact of the exopolysaccharide layer on biofilms,adhesion and resistance to stress in Lactobacillus johnsonii FI9785

Background

The bacterial cell surface is a crucial factor in cell-cell and cell-host interactions. Lactobacillus johnsonii FI9785 produces an exopolysaccharide (EPS) layer whose quantity and composition is altered in mutants that harbour genetic changes in their eps gene clusters. We have assessed the effect of changes in EPS production on cell surface characteristics that may affect the ability of L. johnsonii to colonise the poultry host and exclude pathogens.

Results

Analysis of physicochemical cell surface characteristics reflected by Zeta potential and adhesion to hexadecane showed that an increase in EPS gave a less negative, more hydrophilic surface and reduced autoaggregation. Autoaggregation was significantly higher in mutants that have reduced EPS, indicating that EPS can mask surface structures responsible for cell-cell interactions. EPS also affected biofilm formation, but here the quantity of EPS produced was not the only determinant. A reduction in EPS production increased bacterial adhesion to chicken gut explants, but made the bacteria less able to survive some stresses.

Conclusions

This study showed that manipulation of EPS production in L. johnsonii FI9785 can affect properties which may improve its performance as a competitive exclusion agent, but that positive changes in adhesion may be compromised by a reduction in the ability to survive stress.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-015-0347-2) contains supplementary material, which is available to authorized users.     

Adults with Down syndrome have reduced cardiac response after light exercise testing

Objective

Physical fitness is reduced in adults with Down syndrome (DS). The present study was conducted to elucidate the exercise response in adults with DS.

Design

Case controlled before-after trial.

Setting

Residential centre for people with intellectual disabilities.

Participants

96 Adults with DS, 25 non-DS adults with an intellectual disability, 33 controls.

Interventions

Echocardiography to exclude heart defects and to measure cardiac index (CI) in the supine position, supine position with raised legs, and following ten knee bends.

Main outcome measure

Exercise testing

Results

At rest, mean CI was not significantly different between persons with DS and controls (2.3 vs. 2.4 l/min/m², p = 0.3). However, mean CI after exercise was significantly lower in DS (2.9 vs. 3.7 l/min/m², p < 0.001) and mean CI increase from rest to exercise was more than 50% lower in DS. On the contrary, CI after exercise was similar among controls and non-DS adults with an intellectual disability. Significantly lower stroke volumes in DS were found with insufficient heart rate response.

Conclusions

CI at rest was similar in adults with DS and controls; however persons with DS have a diminished cardiac response to exercise. Stroke volumes were significantly lower in DS during exercise and a compensated heightened heart rate was absent.     

Common Genetic Variation in the Human FNDC5 Locus,Encoding the Novel Muscle-Derived ‘Browning’ Factor Irisin,Determines Insulin Sensitivity

Aims/hypothesis

Recently, the novel myokine irisin was described to drive adipose tissue ‘browning’, to increase energy expenditure, and to improve obesity and insulin resistance in high fat-fed mice. Here, we assessed whether common single nucleotide polymorphisms (SNPs) in the FNDC5 locus, encoding the irisin precursor, contribute to human prediabetic phenotypes (overweight, glucose intolerance, insulin resistance, impaired insulin release).

Methods

A population of 1,976 individuals was characterized by oral glucose tolerance tests and genotyped for FNDC5 tagging SNPs. Subgroups underwent hyperinsulinaemic-euglycaemic clamps, magnetic resonance imaging/spectroscopy, and intravenous glucose tolerance tests. From 37 young and 14 elderly participants recruited in two different centres, muscle biopsies were obtained for the preparation of human myotube cultures.

Results

After appropriate adjustment and Bonferroni correction for the number of tested variants, SNPs rs16835198 and rs726344 were associated with in vivo measures of insulin sensitivity. Via interrogation of publicly available data from the Meta-Analyses of Glucose and Insulin-related traits Consortium, rs726344’s effect on insulin sensitivity was replicated. Moreover, novel data from human myotubes revealed a negative association between FNDC5 expression and appropriately adjusted in vivo measures of insulin sensitivity in young donors. This finding was replicated in myotubes from elderly men.

Conclusions/interpretation

This study provides evidence that the FNDC5 gene, encoding the novel myokine irisin, determines insulin sensitivity in humans. Our gene expression data point to an unexpected insulin-desensitizing effect of irisin.     

The relationship of creatine kinase variability with body composition and muscle damage markers following eccentric muscle contractions

[Purpose]

The purpose of the study was to investigate the relationship between CK variability and body composition and muscle damage markers following eccentric exercise.

[Methods]

Total 119 healthy male subjects were recruited to perform 50 eccentric contractions consisted of 2 sets of 25 contractions. Then, blood creatine kinase (CK) activity was analyzed to divide into three groups based on their CK activity levels. Maximum isometric strength (MIS), muscle soreness (SOR) and body composition data were obtained before and after exercise.

[Results]

The results showed that high CK responders had a significant decrease in MIS (p<0.001) and greater SOR (p<0.01) following eccentric exercise compared to low CK responders. Percent body fat was also higher in high responders compared to low responders (p=0.014). Peak CK activity was significantly correlated with MIS and SOR but no correlation with % body fat, muscle mass, and body mass index.

[Conclusion]

CK variability following eccentric exercise is closely related to MIS and SOR and % body fat may be a potent factor for CK variability.     

Endurance exercise training inhibits neointimal formation via enhancement of FOXOs expression in balloon-induced atherosclerosis rat model

[Purpose]

This study investigated the effect of endurance exercise on neointimal formation, endothelial-dependant relaxation and FOXO expression in balloon-induced carotid arteries of rats.

[Methods]

Male SD(Sprague-Dawley) rats of 8 weeks ages were randomly divided into 3 groups; Sham-operated control (SO, n=10), Balloon-induced control (BIC, n=10), and Balloon-induced exercise (BIE, n=10). Endurance exercise training was performed on treadmill (18 m/min, 0% grade, 60 min/day, 5 days/week, 4 weeks).

[Results]

Body weight is significantly reduced in BIE compared with BIC. Neointiaml formation in BIC was significantly higher than SO, but it was significantly recovered in BIE compared with BIC. Endothelial-dependent relaxation in BIC was significantly lower than SO, but it was significantly recovered in BIE compared with BIC and expression of FOXO1 and FOXO3a also were significantly increased BIE compared with BIC.

[Conclusion]

These data suggest that endurance exercise inhibits neointimal formation and endothelial-dependent relaxation via FOXO expression in balloon-induce atherosclerosis rat model.     

Abnormalities of AMPK Activation and Glucose Uptake in Cultured Skeletal Muscle Cells from Individuals with Chronic Fatigue Syndrome

Background

Post exertional muscle fatigue is a key feature in Chronic Fatigue Syndrome (CFS). Abnormalities of skeletal muscle function have been identified in some but not all patients with CFS. To try to limit potential confounders that might contribute to this clinical heterogeneity, we developed a novel in vitro system that allows comparison of AMP kinase (AMPK) activation and metabolic responses to exercise in cultured skeletal muscle cells from CFS patients and control subjects.

Methods

Skeletal muscle cell cultures were established from 10 subjects with CFS and 7 age-matched controls, subjected to electrical pulse stimulation (EPS) for up to 24h and examined for changes associated with exercise.

Results

In the basal state, CFS cultures showed increased myogenin expression but decreased IL6 secretion during differentiation compared with control cultures. Control cultures subjected to 16h EPS showed a significant increase in both AMPK phosphorylation and glucose uptake compared with unstimulated cells. In contrast, CFS cultures showed no increase in AMPK phosphorylation or glucose uptake after 16h EPS. However, glucose uptake remained responsive to insulin in the CFS cells pointing to an exercise-related defect. IL6 secretion in response to EPS was significantly reduced in CFS compared with control cultures at all time points measured.

Conclusion

EPS is an effective model for eliciting muscle contraction and the metabolic changes associated with exercise in cultured skeletal muscle cells. We found four main differences in cultured skeletal muscle cells from subjects with CFS; increased myogenin expression in the basal state, impaired activation of AMPK, impaired stimulation of glucose uptake and diminished release of IL6. The retention of these differences in cultured muscle cells from CFS subjects points to a genetic/epigenetic mechanism, and provides a system to identify novel therapeutic targets.     

Resistance exercise training increase activation of AKT-eNOS and Ref-1 expression by FOXO-1 activation in aorta of F344 rats

Purpose

This study investigated the effects of resistance exercise on the Akt-eNOS, the activation of antioxidant protein and FOXO1 in the aorta of F344 rats.

Methods

Male 7 week-old F344 rats were randomly divided into 2 groups: a climbing group (n = 6) and a sedentary group (n = 6). H&E staining and western blotting were used to analyze the rat aortas and target proteins.

Results

Resistance exercise training did not significantly affect aortic structure. Phosphorylation of AKT and eNOS and expression of MnSOD and Ref-1 were significantly increased while FOXO1 phosphorylation was significantly decreased in the resistance exercise group compared with the sedentary group.

Conclusion

We demonstrate that resistance exercise activates the Akt-eNOS and Ref-1 protein without changes to aortic thickness via FOXO-1 activation in the aorta of F344 rats.     

Effect of a 12-week walking exercise program on body composition and immune cell count in patients with breast cancer who are undergoing chemotherapy

Purpose

The purpose of this study was to examine the effect of a 12-week walking exercise program on body composition and immune cell count in patients with breast cancer who are undergoing chemotherapy.

Methods

Twenty patients (age, 47.8 ± 3.12) participated in the study. Body composition (weight, body mass index, muscle weight, body fat mass, and percent body fat) and the cell counts for immune cells (white blood corpuscles, lymphocytes, helper T cells, cytotoxic T cells, natural killer cells, and natural killer T cells) were measured before and after the 12-week walking exercise program. SPSS 17.0 statistical software was used. The two-way repeated ANOVA with post hoc was used to determine the difference between time and interaction.

Results

There were significant reductions in the weight (p < .05), BMI (p < .01), and percent body fat (p < .05) after the 12-week walking exercise program. However, the immune cell counts did not change significantly.

Conclusion

These results indicated that the 12-week walking exercise program had an effect on the balances among weight, BMI and percent body fat in patients with breast cancer.     

Effect of aerobic exercise training on non-alcoholic fatty liver disease induced by a high fat diet in C57BL/6 mice

[Purpose]

The aim of this study was to investigate the effects of aerobic exercise training on a high fat diet (HFD)-induced fatty liver and its metabolic complications in C57BL/6 mice.

[Methods]

Mice at 5-month old (n = 30) were randomly assigned to standard chow (SC + CON, n = 10) and high-fat diet (HFD, n = 20), and they were subjected to SC and HFD, respectively, for 23-week. After 15-week of HFD, mice in the HFD group were further assigned to HFD (HFD + CON, n = 10) or exercise training (HFD + EX, n = 10) groups. The HFD + EX mice were subjected to aerobic treadmill running during the last 8-week of the 23-week HFD course. Outcomes included hepatic steatosis, insulin resistance, and expression of genes involved in mitochondrial function and/or fatty oxidation as well as de novo lipogenesis and/or triacylglycerol (TAG) synthesis.

[Results]

Treadmill running ameliorated impaired glucose tolerance and insulin resistance secondary to the HFD. The beneficial effects of treadmill running were associated with enhanced molecular markers of mitochondrial function and/or fatty acids oxidation (i.e., PPARα and CPT1a mRNAs, pAMPK/AMPK, pACC, and SIRT1 protein) as well as suppressed expression of de novo lipogenesis and/or TAG synthesis (i.e., SREBP1c, lipin1 and FAS mRNAs) in the liver.

[Conclusion]

The current findings suggest that aerobic exercise training is an effective and non-pharmacological means to combat fatty liver and its metabolic complications in HFD-induced obese mice.     

Effects of combined exercise on cardiovascular risk factors and serum BDNF level in mid-aged women

[Purpose]

The purposes of this study is first to examine a positive effect of long term combined exercise including aerobic and resistance exercise on increasing level of serum BDNF, and investigate how aerobic exercise is related to improving BDNF circulation and resistance exercise improves fat oxidation in mid-aged women.

[Methods]

Initially, 30 mid-aged women, according to their exercise preference, was randomly assigned as a non-exercise group (n=7, control group; CG) and exercise group (n=23). Then, 23 exercise participants were divided by aerobic exercise group (n=15, AEG) and combination of aerobic and resistance exercise group (n=8, CEG). Prior to the experiment, all participants’maximal oxygen uptake (VO₂max), body composition, and blood factors were measured. Changes (Δ delta value) in body composition, fitness level, and serum BDNF level of the different groups were tested through one way ANOVA.

[Results]

For AEG and CG after 24 weeks, VO₂max and high-density lipoprotein cholesterol (HDL-C) were significantly increased. During this period, CEG had significant increase in muscular strength and decrease in triglyceride (TG) total cholesterol (TC)/HDL-C (p=0.013). Continuously, serum BDNF concentration of both AEG and CEG was significantly increased (F=6.328, p=0.001) compared to CG. There, however, was no significant between-group difference.

[Conclusion]

Although there was no difference in serum BDNF level between AEG and CEG, we confirmed that CEG may have a possibility of positive changes in increase of serum BDNF level in mid-aged women.     

Chronic Exercise Increases Plasma Brain-Derived Neurotrophic Factor Levels,Pancreatic Islet Size,and Insulin Tolerance in a TrkB-Dependent Manner

Background

Physical exercise improves glucose metabolism and insulin sensitivity. Brain-derived neurotrophic factor (BDNF) enhances insulin activity in diabetic rodents. Because physical exercise modifies BDNF production, this study aimed to investigate the effects of chronic exercise on plasma BDNF levels and the possible effects on insulin tolerance modification in healthy rats.

Methods

Wistar rats were divided into five groups: control (sedentary, C); moderate- intensity training (MIT); MIT plus K252A TrkB blocker (MITK); high-intensity training (HIT); and HIT plus K252a (HITK). Training comprised 8 weeks of treadmill running. Plasma BDNF levels (ELISA assay), glucose tolerance, insulin tolerance, and immunohistochemistry for insulin and the pancreatic islet area were evaluated in all groups. In addition, Bdnf mRNA expression in the skeletal muscle was measured.

Principal Findings

Chronic treadmill exercise significantly increased plasma BDNF levels and insulin tolerance, and both effects were attenuated by TrkB blocking. In the MIT and HIT groups, a significant TrkB-dependent pancreatic islet enlargement was observed. MIT rats exhibited increased liver glycogen levels following insulin administration in a TrkB-independent manner.

Conclusions/Significance

Chronic physical exercise exerted remarkable effects on insulin regulation by inducing significant increases in the pancreatic islet size and insulin sensitivity in a TrkB-dependent manner. A threshold for the induction of BNDF in response to physical exercise exists in certain muscle groups. To the best of our knowledge, these are the first results to reveal a role for TrkB in the chronic exercise-mediated insulin regulation in healthy rats.     

Effect of exercise on hyperactivity,impulsivity and dopamine D2 receptor expression in the substantia nigra and striatum of spontaneous hypertensive rats

[Purpose]

Attention-deficit/hyperactivity disorder (ADHD) is a heritable, chronic, neurobehavioral disorder that is characterized by hyperactivity, inattention, and impulsivity. It is commonly believed that the symptoms of ADHD are closely associated with hypo-function of the dopamine system. Dopamine D₂ receptor activation decreases the excitability of dopamine neurons, as well as the release of dopamine. Physical exercise is known to improve structural and functional impairments in neuropsychiatric disorders. We investigated the therapeutic effect of exercise on ADHD.

[Methods]

Open field task and elevated-plus maze task were used in the evaluation of hyperactivity and impulsivity, respectively. Dopamine D₂ receptor expression in the substantia nigra and striatum were evaluated by western blotting.

[Results]

The present results indicated that ADHD rats showed hyperactivity and impulsivity. Dopamine D₂ receptor expression in the substantia nigra and striatum were increased in ADHD rats. Exercise alleviated hyperactivity and impulsivity in ADHD rats. Furthermore, dopamine D₂ receptor expression in ADHD rats was also decreased by exercise.

[Conclusion]

We thus showed that exercise effectively alleviates ADHD-induced symptoms through enhancing dopamine D₂ expression in the brain.     

Expressed Prostate Secretions in the Study of Human Papillomavirus Epidemiology in the Male

Introduction

Exploring different sampling sites and methods is of interest for studies of the epidemiology of HPV infections in the male. Expressed prostate secretions (EPS) are obtained during digital rectal examination (DRE), a daily routine urological diagnostic procedure, following massage of the prostate.

Materials and Methods

Urethral swabs and EPS samples were obtained from a consecutive sample of 752 men (mean age 32.4 years; median life-time sex partners 34) visiting urology outpatient clinics in St. Petersburg, Russia and tested for HPV DNA by general primer PCR, followed by genotyping using Luminex.

Results

Overall, 47.9% (360/752) of men were HPV-positive, with 42.0% (316/752) being positive for high-risk (HR-) HPV and 12.6% (95/752) for multiple HPV types. HPV-positivity in the EPS samples was 32.6% (27.7% HR-HPV) and in the urethral samples 25.9% (24.5% HR-HPV). 10.6% were HPV positive in both EPS and urethral samples. 6.4% had the same HPV-type in both EPS and urethral samples. 10.6% were HPV positive in both EPS and urethral samples. 6.4% had the same HPV-type in both EPS and urethral samples. The concordance between the urethral samples and EPS was 62.5% (470/752), with 80 cases double positive and 390 cases double negative in both sites. The sensitivity of urethral samples for overall HPV detection was 54.2% (195/360). Compared to analysis of urethral samples only, the analysis of EPS increased the HPV prevalence in this population with 26.2%.

Conclusion

EPS represent informative sampling material for the study of HPV epidemiology in the male.     

Patients with Encapsulating Peritoneal Sclerosis Have Increased Peritoneal Expression of Connective Tissue Growth Factor (CCN2), Transforming Growth Factor-β1, and Vascular Endothelial Growth Factor

Introduction

Encapsulating peritoneal sclerosis (EPS) is a devastating complication of peritoneal dialysis (PD). The pathogenesis is not exactly known and no preventive strategy or targeted medical therapy is available. CCN2 has both pro-fibrotic and pro-angiogenic actions and appears an attractive target. Therefore, we studied peritoneal expression of CCN2, as well as TGFβ1 and VEGF, in different stages of peritoneal fibrosis.

Materials and methods

Sixteen PD patients were investigated and compared to 12 hemodialysis patients and four pre-emptively transplanted patients. Furthermore, expression was investigated in 12 EPS patients in comparison with 13 PD and 12 non-PD patients without EPS. Peritoneal tissue was taken during kidney transplantation procedure or during EPS surgery. In a subset of patients, CCN2 protein levels in peritoneal effluent and plasma were determined. Samples were examined by qPCR, histology, immunohistochemistry, and ELISA.

Results

Peritoneal CCN2 expression was 5-fold higher in PD patients compared to pre-emptively transplanted patients (P<0.05), but did not differ from hemodialysis patients. Peritoneal expression of TGFβ1 and VEGF were not different between the three groups; neither was peritoneal thickness. Peritoneum of EPS patients exhibited increased expression of CCN2 (35-fold, P<0.001), TGFβ1 (24-fold, P<0.05), and VEGF (77-fold, P<0.001) compared to PD patients without EPS. In EPS patients, CCN2 protein was mainly localized in peritoneal endothelial cells and fibroblasts. CCN2 protein levels were significantly higher in peritoneal effluent of EPS patients compared to levels in dialysate of PD patients (12.0±4.5 vs. 0.91±0.92 ng/ml, P<0.01), while plasma CCN2 levels were not increased.

Conclusions

Peritoneal expression of CCN2, TGFβ1, and VEGF are significantly increased in EPS patients. In early stages of peritoneal fibrosis, only CCN2 expression is slightly increased. Peritoneal CCN2 overexpression in EPS patients is a locally driven response. The potential of CCN2 as biomarker and target for CCN2-inhibiting agents to prevent or treat EPS warrants further study.     

Possible influences of exercise-intensity-dependent increases in non-cortical hemodynamic variables on NIRS-based neuroimaging analysis during cognitive tasks: Technical note

[Purpose]

Functional near-infrared spectroscopy (fNIRS) provides functional imaging of cortical activations by measuring regional oxy- and deoxy-hemoglobin (Hb) changes in the forehead during a cognitive task. There are, however, potential problems regarding NIRS signal contamination by non-cortical hemodynamic (NCH) variables such as skin blood flow, middle cerebral artery blood flow, and heart rate (HR), which are further complicated during acute exercise. It is thus necessary to determine the appropriate post-exercise timing that allows for valid NIRS assessment during a task without any increase in NCH variables. Here, we monitored post-exercise changes in NCH parameters with different intensities of exercise.

[Methods]

Fourteen healthy young participants cycled 30, 50 and 70% of their peak oxygen uptake (Vo_2peak) for 10 min per intensity, each on different days. Changes in skin blood flow velocity (SBFv), middle cerebral artery mean blood velocity (MCA V_mean) and HR were monitored before, during, and after the exercise.

[Results]

Post-exercise levels of both SBFv and HR in contrast to MCA V_mean remained high compared to basal levels and the times taken to return to baseline levels for both parameters were delayed (2-8 min after exercise), depending upon exercise intensity.

[Conclusion]

These results indicate that the delayed clearance of NCH variables of up to 8 min into the post-exercise phase may contaminate NIRS measurements, and could be a limitation of NIRS-based neuroimaging studies.     

Aerobic Exercise for Parkinson's Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Although some trials assessed the effectiveness of aerobic exercise for Parkinson''s disease (PD), the role of aerobic exercise in the management of PD remained controversial.

Objective

The purpose of this systematic review is to evaluate the evidence about whether aerobic exercise is effective for PD.

Methods

Seven electronic databases, up to December 2013, were searched to identify relevant studies. Two reviewers independently extracted data and assessed methodological quality based on PEDro scale. Standardised mean difference (SMD) and 95% confidence intervals (CI) of random-effects model were calculated. And heterogeneity was assessed based on the I² statistic.

Results

18 randomized controlled trials (RCTs) with 901 patients were eligible. The aggregated results suggested that aerobic exercise should show superior effects in improving motor actions (SMD, −0.57; 95% CI −0.94 to −0.19; p = 0.003), balance (SMD, 2.02; 95% CI 0.45 to 3.59; p = 0.01), and gait (SMD, 0.33; 95% CI 0.17 to 0.49; p<0.0001) in patients with PD, but not in quality of life (SMD, 0.11; 95% CI −0.23 to 0.46; p = 0.52). And there was no valid evidence on follow-up effects of aerobic exercise for PD.

Conclusion

Aerobic exercise showed immediate beneficial effects in improving motor action, balance, and gait in patients with PD. However, given no evidence on follow-up effects, large-scale RCTs with long follow-up are warrant to confirm the current findings.     

Work-Related Pain in Extrinsic Finger Extensor Musculature of Instrumentalists Is Associated with Intracellular pH Compartmentation during Exercise

Background

Although non-specific pain in the upper limb muscles of workers engaged in mild repetitive tasks is a common occupational health problem, much is unknown about the associated structural and biochemical changes. In this study, we compared the muscle energy metabolism of the extrinsic finger extensor musculature in instrumentalists suffering from work-related pain with that of healthy control instrumentalists using non-invasive phosphorus magnetic resonance spectroscopy (³¹P-MRS). We hypothesize that the affected muscles will show alterations related with an impaired energy metabolism.

Methodology/Principal Findings

We studied 19 volunteer instrumentalists (11 subjects with work-related pain affecting the extrinsic finger extensor musculature and 8 healthy controls). We used ³¹P-MRS to find deviations from the expected metabolic response to exercise in phosphocreatine (PCr), inorganic phosphate (Pi), Pi/PCr ratio and intracellular pH kinetics. We observed a reduced finger extensor exercise tolerance in instrumentalists with myalgia, an intracellular pH compartmentation in the form of neutral and acid compartments, as detected by Pi peak splitting in ³¹P-MRS spectra, predominantly in myalgic muscles, and a strong association of this pattern with the condition.

Conclusions/Significance

Work-related pain in the finger extrinsic extensor muscles is associated with intracellular pH compartmentation during exercise, non-invasively detectable by ³¹P-MRS and consistent with the simultaneous energy production by oxidative metabolism and glycolysis. We speculate that a deficit in energy production by oxidative pathways may exist in the affected muscles. Two possible explanations for this would be the partial and/or local reduction of blood supply and the reduction of the muscle oxidative capacity itself.     

Six week swimming followed by acute uptakes of ginsenoside Rg1 may affect aerobic capacity of SD rats

[Purpose]

The purpose of this study is to examine the effects of six-weeks of endurance swim training and short-term intake of Rg1 on the expression of related proteins as well as improvement of aerobic exercise capacity in 8-week-old male SD rats.

[Methods]

The groups were divided into placebo (NP, n=6), Rg1 (NRG, n=6), exercise+placebo (EP, n=7), and exercise+Rg1 (ERG, n=7). On completion of the 6-week swimming exercise, Rg1-intake groups were treated with acute uptakes (3 times within 24hrs) of Rg1. After the treatment, all groups were subjected to a swim to exhaustion test, and then the mass of muscle tissue, mRNA expression level and activity of citrate synthase (CS) were analyzed on plantaris.

[Results]

There were no differences in the effect of 6-week swimming exercise and short-term intake of Rg1 on body weight and muscle mass between groups. Although the CS mRNA expression was elevated in the exercise group and combined treatment group, there was no significant difference in CS activity. Acute uptakes of Rg1 did not affect swimming time to exhaustion, but it was increased by 235% and 314% by the 6-weeks of exercise and combined treatment of exercise and Rg1, respectively, which suggests that the combined treatment increased the effect on the capacity of aerobic exercise.

[Conclusion]

Based on these results, it was confirmed that even a short-term treatment of Rg1 can give an additive effect for improvement of exercise function, and additional studies are needed for the mechanisms and modes of its working.     

Age-related location of manifest accessory pathway and clinical consequences

Background

Accessory pathway (AP) ablation is not always easy. Our purpose was to assess the age-related prevalence of AP location, electrophysiological and prognostic data according to this location.

Methods

Electrophysiologic study (EPS) was performed in 994 patients for a pre-excitation syndrome. AP location was determined on a 12 lead ECG during atrial pacing at maximal preexcitation and confirmed at intracardiac EPS in 494 patients.

Results

AP location was classified as anteroseptal (AS)(96), right lateral (RL)(54), posteroseptal (PS)(459), left lateral (LL)(363), nodoventricular (NV)(22).Patients with ASAP or RLAP were younger than patients with another AP location. Poorly-tolerated arrhythmias were more frequent in patients with LLAP than in other patients (0.009 for ASAP, 0.0037 for RLAP, <0.0001 for PSAP).Maximal rate conducted over AP was significantly slower in patients with ASAP and RLAP than in other patients. Malignant forms at EPS were more frequent in patients with LLAP than in patients with ASAP (0.002) or PSAP (0.001).Similar data were noted when AP location was confirmed at intracardiac EPS. Among untreated patients, poorly-tolerated arrhythmia occurred in patients with LLAP (3) or PSAP (6). Failures of ablation were more frequent for AS or RL AP than for LL or PS AP.

Conclusions

AS and RLAP location in pre-excitation syndrome was more frequent in young patients. Maximal rate conducted over AP was lower than in other locations. Absence of poorly-tolerated arrhythmias during follow-up and higher risk of ablation failure should be taken into account for indications of AP ablation in children with few symptoms.