Panel 4 : Report of the Microbiology Panel

Objective. To perform a comprehensive review of the literature from July 2011 until June 2015 on the virology and bacteriology of otitis media in children. Data Sources. PubMed database of the National Library of Medicine. Review Methods. Two subpanels comprising experts in the virology and bacteriology of otitis media were created. Each panel reviewed the relevant literature in the fields of virology and bacteriology and generated draft reviews. These initial reviews were distributed to all panel members prior to meeting together at the Post-symposium Research Conference of the 18th International Symposium on Recent Advances in Otitis Media, National Harbor, Maryland, in June 2015. A final draft was created, circulated, and approved by all panel members. Conclusions. Excellent progress has been made in the past 4 years in advancing our understanding of the microbiology of otitis media. Numerous advances were made in basic laboratory studies, in animal models of otitis media, in better understanding the epidemiology of disease, and in clinical practice. Implications for Practice. (1) Many viruses cause acute otitis media without bacterial coinfection, and such cases do not require antibiotic treatment. (2) When respiratory syncytial virus, metapneumovirus, and influenza virus peak in the community, practitioners can expect to see an increase in clinical otitis media cases. (3) Biomarkers that predict which children with upper respiratory tract infections will develop otitis media may be available in the future. (4) Compounds that target newly identified bacterial virulence determinants may be available as future treatment options for children with otitis media.Peer reviewe

Early role of vascular dysregulation on late-onset Alzheimer's disease based on multifactorial data-driven analysis

Multifactorial mechanisms underlying late-onset Alzheimer's disease (LOAD) are poorly characterized from an integrative perspective. Here spatiotemporal alterations in brain amyloid-β deposition, metabolism, vascular, functional activity at rest, structural properties, cognitive integrity and peripheral proteins levels are characterized in relation to LOAD progression. We analyse over 7,700 brain images and tens of plasma and cerebrospinal fluid biomarkers from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Through a multifactorial data-driven analysis, we obtain dynamic LOAD–abnormality indices for all biomarkers, and a tentative temporal ordering of disease progression. Imaging results suggest that intra-brain vascular dysregulation is an early pathological event during disease development. Cognitive decline is noticeable from initial LOAD stages, suggesting early memory deficit associated with the primary disease factors. High abnormality levels are also observed for specific proteins associated with the vascular system's integrity. Although still subjected to the sensitivity of the algorithms and biomarkers employed, our results might contribute to the development of preventive therapeutic interventions

Effects of unilateral voluntary and electromyostimulation training on muscular strength on the contralateral limb

This study investigated the effects of unilateral electromyostimulation (EMS) versus voluntary isometric strength (VIM) training on knee extension strength of the contralateral limb, a phenomenon termed cross education, in previously untrained healthy young adults. Subjects in EMS (n=10) and VIM (n=10) groups trained with 40 voluntary or evoked isometric knee extensions, at an intensity of 65% of maximum voluntary contraction force (MVC), three sessions per week for four weeks. Before and after training, both legs were tested for MVC on an isokinetic dynamometer, at 0 deg.s-1 (isometric), 60 and 180 deg.s-1 velocities. The results showed that the EMS and VIM training induced similar strength improvement in the trained limb (P\u3c0.05), as well as cross-education effects (EMS +21.1% and VIM +21.4% in the contralateral limb, both P\u3c0.05) in isometric MVC, but no cross education was found for isokinetic performance. Analysis of integrated EMG showed a trend, but not statistically significant, of increase in the trained groups. No significant variation in knee extension strength, neither in EMG, was found in a control group (n=10). The mechanism of cross education in response to the EMS training, and the application significance of cross education in exercise rehabilitation are of the interests in further studies

Cross-education effect observed in voluntary and electromyostimulation strength training

This study investigated the effects of four weeks of unilateral electromyostimulation(EMS) versus isometric strength training(IM), on knee extension strength of contralateral limb in previously untrained young adults. Subjects performed (IM, n=10) or evoked (EMS, n=10) 40 isometric knee extensions, at an intensity of 65% of maximum voluntary contraction force, three times per week, for four weeks. Pre and post training, both legs were tested for maximum voluntary strength on an isokinetic dynamometer, at 0 deg/s (isometric), 60 and 180 deg/s velocities. The results showed that the EMS and IM training were equally effective to improve strength in these subjects. Both types of training induced a significant cross-education effect in the untrained limb in voluntary isometric strength, but not in the isokinetic torque. The mechanisms underlying this phenomenon require further study

Validation of the Dmax method as a predictor of lactate threshold

INTRODUCTION The concept of anaerobic threshold has been widely used to assess the endurance performance of athletes. Although there is no universally accepted definition of anaerobic threshold, it can be functionally thought of as being the highest exercise intensity at which a physiological steady state can be maintained during prolonged exercise (Stegmann et al., 1981). A number of researchers have put forward a variety of methods for identifying such an intensity from an incremental exercise test. However, the majority of such methods have had problems in regard to their validity, objectivity, reliability and individuality. One method that shows individuality and objectivity is the Dmax method put forward by Cheng et al. in 1992. Validation of this method for cyclists has not been undertaken, therefore, the aim of this study is to determine whether the Dmax is a valid indicator of lactated threshold in response to an incremental cycling exercise. METHODS Subjects. Fourteen male volunteers, aged between 18-30 years, who had at least 12 months cycle endurance training, participated in the study. They had a mean (+/-SD) VO2peak of 63.52+/-10.2 ml/kg/min and body mass of 75.24+/-6.03 kg. Protocol. All subjects completed a series of four exercise tests, including one incremental test till exhaustion and three prolonged exercise trials with constant workloads, on a Monark cycle ergometer. The incremental exercise test was performed to determine the VO2peak and the Dmax point. The workload started from 100 watts for 3 min, then increased by 30 watts every 3 min until volitional exhaustion. In the last 30 s of each workload, venous blood was sampled via a catheter inserted in the subject’s forearm. The blood sample was analysed for whole blood lactate concentration using a YSI-1500 Automatic Lactate Analyser. Expired air was collected and analysed on-line throughout the test for gas concentrations and pulmonary ventilation. The three prolonged exercise trials were performed on separate days with at least one day rest between each trial. The exercises were performed at a constant intensity of either at the Dmax (in watts), or 15 watts below or above the Dmax, respectively, for 30 min or until volitional exhaustion. Blood samples were taken at 5 min intervals for lactate analyses. The exercise intensities of the three trials were randomly assigned to each subject. Calculation of the Dmax. The method involved fitting the subject’s Lactate-Power output profile (from the incremental exercise test) to a third order polynomial curve, then plotting a straight line from the peak lactate concentration to the first lactate point that was 0.4 mmol/L above the resting level (a modification to Cheng et al., 1992). The point with the greatest perpendicular distance from this straight line to the lactate curve was defined as the Dmax, and the corresponding exercise intensity was subsequently determined. Statistics. Lactate concentrations were compared during the prolonged exercise trials and between prolonged exercise intensities using repeated measures Analysis of Variance with Bonferonni adjustments. RESULTS The major findings were that, for the prolonged exercise trial at the intensity of 15 watts above the Dmax, the blood lactate concentration at the end of the exercise was significantly higher than that at the 10th min of the exercise (p\u3c0.05), however, no such a lactate increase was found when exercising either at or 15 watts below the Dmax intensity. The lactate concentration over the last 15 min during the tests was significantly higher in the above-Dmax trial compared with that in the below-Dmax trial (p\u3c0.05). DISCUSSION Coaches and trainers require a valid and reliable method of predicting endurance performance from a single incremental exercise test. Upon that a significant increase in lactate concentration was found during the above-Dmax intensity trial, whilst a plateau of lactate concentration was maintained during the at- or below-Dmax trials, the Dmax appears to be a valid method to predict physiological steady state during such an endurance exercise. The significant lactate concentration difference found between the below- and above-Dmax trials, with only 30 watts difference in intensity, also indicates a good sensitivity of the Dmax method. Considering its individuality, objectivity, sensitivity and validity, the Dmax method could be used as an alternative predictor of lactate threshold. REFERENCES Cheng B., Kuipers H., Snyder A.C., Keizer H.A., Jeukendrup A. & Hesselink M. (1992). A new approach to the determination of ventilatory and lactate thresholds. Int. J. Sports Med. 13(7):518-522. Stegmann H., Kinderman W. & Schnabel A. (1981). Lactate kinetics and individual anaerobic threshold. Int J. Sports Med. 2: 160-165

Cross education effect on EMG observed in unilateral electromyostimulation and voluntary strength training

This study investigated the effects of four weeks of unilateral electromyostimulation (EMS) versus voluntary isometric strength training (VIM), on knee extension strength of contralateral limb in thirty previously untrained young adults. Ten subjects were assigned into each of the EMS, VIM and Control groups. The training groups performed or evoked 40 isometric knee extensions, at the intensity of 65% of maximum voluntary contraction (MVC) force, three times per week. Pre and post the four weeks training, both the trained and contralateral limbs were tested for isometric MVC. Surface EMG was recorded from the rectus femoris, vastus lateralis and vastus medialis muscles during MVC. The results showed that the EMS and VIM training had a similar effect on strength improvement in the trained limb (21.1% in EMS, 24.5% in VIM, both P\u3c0.05. -0.4% in Control, non significant (n.s.)). Both types of training induced significant cross-education effect on isometric MVC of the contralateral limb (21.1% in EMS, 21.4% in VIM, both P\u3c0.05. 2.4% in Control, n.s.). The analysis of integrated EMG (iEMG, sum of three muscles) showed a trend of increment in both trained limb (16.6% in EMS, 29.8% in VIM, -7.0% in Control, all n.s.), and the contraleteral limb in the training groups (10.2% in EMS, 21.6% in VIM, -7.8% in Control, all n.s.). It appeared that neural adaptation, as reflected in the increased EMG, could be attributed at least partly to the improved the voluntary strength in both trained and contralateral limbs. However, the mechanism underlying the cross-education effect and EMG variation in response to the EMS training is not clear and requires further study