bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resistance of the Brain to Escherichia coli K1 Infection Depends on MyD88 Signaling and the Contribution of Neutrophils and Monocytes
Authors: Ribes Sandra , Regen Tommy , Meister Tanja , Tauber Simone C. , Schütze Sandra , Mildner Alexander , Mack Matthias , Hanisch Uwe-Karsten , Nau Roland 
Published: March 2013

ABSTRACTEscherichia coliis the leading cause of Gram-negative neonatal bacterial meningitis and also causes meningitis and meningoencephalitis in older and immunocompromised patients. Here, we determined the contribution of granulocytes, monocytes, and TLR signaling cascades in the resistance of adult mice toEscherichia coliK1 brain infection. Deficiency in MyD88 (myd88−/−) but not in TRIF (triflps2) adaptor proteins dramatically reduced the survival of animals. Depletion of CD11b+Ly-6G+Ly-6Cintneutrophils by application of the anti-Ly-6G (1A8) monoclonal antibody (MAb) led to higher bacterial loads in cerebellum and spleen tissue and resulted in increased mortality compared to those of isotype-treated controls. Depletion of CD11b+Ly-6G+Ly-6Cintneutrophils and CD11b+Ly-6G−Ly-6Chighmonocytes by administration of the anti-Gr-1 (RB6-8C5) MAb rendered mice even more susceptible to the infection, with higher central nervous system (CNS) and spleen bacterial burdens than anti-Ly-6G-treated animals. Depletion of ∼50% of CD11b+Ly-6G−Ly-6Chighmonocytes by injection of the anti-CCR2 (MC-21) MAb resulted in a trend toward higher mortality compared to that with isotype treatment. Production of interleukin 1β (IL-1β), IL-6, KC, and MIP-2 in the CNS strongly depended on the bacterial load: increased levels of these cytokines/chemokines were found after depletion of CD11b+Ly-6G+Ly-6Cintneutrophils alone or together with CD11b+Ly-6G−Ly-6Chighmonocytes. These findings identify Toll-like receptor (TLR)-MyD88 signaling and neutrophil and monocyte activity as critical elements in the early host defense againstE. colimeningitis.
A novel brain imaging technology for concussion management demonstrated on a scopolamine induced cognitive impairment model
Authors: Reches Amit , Gal Noga , Kerem Dani , Grossman Shany , Dickman Dalia , Geva Amir 
Published: March 2013

ObjectiveThe primary purpose of the current study was to investigate the clinical applicability of Brain Network Activation (BNA), a novel event-related-potential (ERP)-based brain imaging technology, to assess cognitive changes following scopolamine-induced impairment.DesignIn a double-blind, placebo-controlled, crossover study subjects received scopolamine to induce cognitive impairment. An auditory oddball task was performed while high density EEG data was recorded before, during and 1 week after impairment reversal.SettingsResearch center (CRO). Clinical care not applicable.ParticipantsHealthy volunteers of both genders aged 18–45 years. Fifteen participants were enrolled, 13 completed the study.Interventions0.4 mg of scopolamine was administered subcutaneously.Main Outcome MeasurementsBrain network activity of subjects was evaluated and quantified using the BNA technology. Significant change in BNA scores across visits for each subject was identified by a Minimal Important Difference (MID) measure. MID defines the range of normal variability between scores from two repeated visits, based on an external control database (N=75). Changes in BNA scores which cross the MID indicate a significant level of cognitive impairment.ResultsA significant decline (p<0.01) in BNA scores was observed as a result of scopolamine induced impairment, followed by a significant recovery (p<0.001). At recovery, scores returned to baseline (p=0.58). MID analysis showed that the effect of scopolamine was significantly larger than that of placebo in individual subjects (p<0.05).ConclusionsPharmacologically induced cognitive impairment was successfully identified utilising the BNA technology. The technology could potentially be used clinically to provide functional information regarding network-based cognitive impairment associated with concussion.
Are clinical measures of cervical flexor endurance, divided attention and dynamic visual acuity different in elite youth ice hockey players who report a previous history of concussion compared to those who do not?
Authors: Schneider Kathryn J , Emery Carolyn A , Kang Jian , Meeuwisse Willem 
Published: March 2013

ObjectiveTo evaluate differences in baseline measures of cervical flexor endurance (CFE), walking while talking (WWTT) and computerised dynamic visual acuity (cDVA) in elite youth ice hockey players who do and do not report a previous history of concussion.DesignCross-sectional.SettingCommunity ice rinks and sport medicine clinic in Calgary, Alberta, Canada.Participants532 Bantam (12–14 years) and Midget (15–17 years) ice hockey players. Assessment of Risk Factors: Previous history of concussion was reported on a preseason demographic questionnaire.Main Outcome Measurements458 players completed preseason tests of CFE, WWTT and cDVA (2011/12 hockey season).ResultsMultivariate linear regression, adjusted for cluster, age group and sex was used to estimate mean differences in clinical measurement scores by concussion history (yes/no). There was no evidence of a difference in CFE score or cDVA scores at 85° per second. The mean time to complete WWTT complex compared to self-selected walking speed in midget females reporting a previous concussion was 3.10 s higher (95% CI 1.40 to 4.79) than in midget females not reporting a previous concussion. Players with previous concussion had significantly lower cDVA score at 120° per second than players without a previous concussion [cDVAleft=−0.033 logMAR (95% CI −0.064 to −0.0019); Bantam players cDVAright=−0.062 logMAR (95% CI −0.12 to −0.004).ConclusionsTasks of divided attention decreased mean self-selected walking speed more in midget femaless with a previous history of concussion compared to those without. Computerised dynamic visual acuity at 120° per second was lower in players with a previous history of concussion.AcknowledgementsThe University of Calgary Sport Injury Prevention Research Centre is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic Committee. We acknowledge the support of Alberta Innovates Health Solutions, the Alberta Children's Hospital Institute for Child and Maternal Health (Alberta Children's Hospital Foundation), and Talisman Energy.
Genetic polymorphisms, concussion risk, and post concussion neurocognitive deficits in college and high school athletes
Authors: Terrell Thomas R , Bostick Roberd M , Barth Jeffery , McKeag Douglas , Cantu Robert C , Sloane Rick , Galloway Leslie , Erlanger David , Valentine Verle , Bielak K 
Published: March 2013

ObjectiveTo investigate associations ofAPOEandTaugene polymorphisms with sports-related acute concussions and baseline to post-concussion neuropsychological test score changes.DesignMulti-center prospective cohort study.SettingScholarship athletes at 21 universities and 4 high schools Participants: 3218 athletes playing football (70%) or soccer (23%).Assessment of Risk FactorsAPOE,APOEG-219T promoter (APOEProm),Tauexon 6 Ser53Pro (TauSer), andTauexon 6 Hist47Tyr (TauHis) genetic polymorphisms.Main Outcome Measurements(1) Acute concussions and (2) differences between baseline and 24–72 h post-concussion Headminder Neuropsychological Test Scores of Simple and Complex Reaction Time (SRT and CRT, respectively) and Processing Speed.ResultsThere were a total of 131 athletes with incident concussions and genetic data and neuropsychological test scores. There were no statistically significant differences in frequencies of acute concussions according to genotypes by χ2test. By t-test, the mean baseline to post-concussion neuropsychological changes were statistically significantly greater for CRT and SRT in those with the TauSer ‘TT’ genotype and for CRT in those with the APOEProm ‘TT’ genotype, and borderline significantly greater in those with the TauSer ‘TT’ genotype (p=0.09).ConclusionsThe statistically significantly worse mean baseline to post-concussion neuropsychological test scores in those with the APOEProm and TauSer polymorphisms suggests a possible genetic influence on post-concussion neurocognitive recovery. These preliminary findings provide no evidence for associations of the fourAPOEandTaugene polymorphisms investigated with acute concussions, although the small sample size and lack of control for confounders are limitations.AcknowledgementsGrant funding was provided through the NOCSAE (National Operating Committee for Safety Athletic Equipment) and the American Medical Society for Sports Medicine (AMSSM) Foundations. The opinions expressed in this abstract are not those of NOCSAE or AMSSM.Competing interestsNone.
Concussions in National Hockey League (NHL) players: 5-year video analysis
Authors: Hutchison Michael , Comper Paul 
Published: March 2013

ObjectivesTo understand, through video analysis, how playing characteristics and mechanism of injury contribute to concussions in the National Hockey League (NHL).SettingNational Hockey League.DesignProspective case series of concussions over a 5 year period of regular season NHL games (2006–2011).SubjectsDigital video images of 341 diagnosed concussions of NHL players.Outcome MeasuresConcussions were analysed and coded using the Heads Up Checklist (HUC). The HUC consists of 17 groups of factors, categorised within three main domains: (1) Physical Event, (2) Equipment, and (3) Game Situation. In addition, player characteristics (ie, height, weight, and position) were also captured.ResultsDuring the first 4 years of study period, a common injury mechanism characterised by player-to-player contact and resulting in contact to the head by the shoulder, elbow, or gloves, was identified. Several important characteristics were also discerned: (i) Contact often to the lateral aspect of the head; (ii) Player was often not in possession of the puck; and (iii) No penalty was called on the play. For the 2010–11 season, despite the absolute number of concussions remaining similar to previous years of study, the mechanism of direct contact to the head accounted for fewer concussions observed.ConclusionsBased on the results from this longitudinal study, it appears that majority of concussions are a result of direct contact to the head. Initiatives to reduce eliminate specific behaviours appears to have had an impact as fewer direct contacts to the head were identified.Competing interestsOne of the authors (PC) is a paid consultant for the National Hockey League Players' Association (NHLPA).
The development of an observational tool to code knockouts in Mixed Martial Arts (MMA)
Authors: Hutchison Michael , Cusimano Michael , Lawrence David , Singh Tanveer 
Published: March 2013

ObjectiveTo develop an observational tool to reliably code the situational characteristics and mechanism of contact for fights ending in knockout (KO) or technical KO (TKO).DesignDigital video images and fight card information were collected retrospectively for UFC events during 2006–2009.SubjectsTwo coders independently viewed and completed to the Mixed Martial Arts (MMA) ‘Knockout’ Tool for 60 events (30=KO's 30=TKO's) chosen randomly from the pool of identified events during 2006–2009.Outcome MeasuresThe MMA ‘Knockout’ Tool was developed by consensus and consists of 17 factors, including theSituational Context(eg, Round, octagon location, technical position),Pre-KO/TKO Strike Profile(eg, striking implement, strike location),Assessment of Fighters(eg, visual obstruction, clinical signs of concussion), andKO strike profile(eg, striking implement, strike location, head motion, additional head impacts). Intercoder agreements for each factor of interest were calculated using weighted κ coefficient.ResultsCoders achievedsubstantial agreementfor the majority of the factors with κ coefficients ranging from 0.46 to 1.00. An overall reliability value was calculated based on all factors of the MMA ‘Knockout’ Tool, with an average κ coefficient of 0.81.ConclusionThe MMA ‘Knockout’ Tool is reliable for coding the situational characteristics and mechanism of contact(s) for fights ending in a TKO or KO.AcknowledgementsThe Canadian Institutes of Health Research (CIHR) Strategic Team in Applied Injury Research funded this researchCompeting interestsNone.
Detecting suboptimal effort in concussion management settings with the axon sports CCAT
Authors: Louey Andrea G , Maruff Paul , Cromer Jason A 
Published: March 2013

ObjectiveAccurate concussion management relies on the integrity of baseline and after injury assessments to reflect actual cognitive abilities. This study assessed performance differences in optimal versus malingering conditions, and evaluated the ability of embedded effort indicators in the Axon Sports Computerised Cognitive Assessment Tool (CCAT) to detect suboptimal effort.DesignWithin-subject, randomised, with Optimal and Feigned impairment conditions.SettingCognitive testing with the CCAT was completed at a university clinic.SubjectsA healthy adult sample aged between 16 and 30 years.InterventionSubjects were randomly assigned to one of two conditions: (1) Practice-Optimal-Feigned or (2) Practice-Feigned-Optimal. All subjects were instructed to perform to the best of their abilities during the Practice and Optimal test sessions, and were instructed to feign a malingering condition where they were seeking compensation for a head injury in the Feigned test session.Outcome MeasurementsMean reaction times and accuracy scores on each of the four CCAT tasks for the Optimal versus Feigned conditions. Overall test validity and individual integrity criteria on the CCAT for assessment of the embedded effort indictors.ResultsSubjects displayed reduced reaction times and decreased accuracy during the Feigned condition versus the Optimal condition. The CCAT had 100% sensitivity identifying intentional suboptimal effort in this sample, with 93% specificity.ConclusionsIdentifiable changes in cognitive performance occurred when subjects feigned impairment during cognitive testing. Embedded effort indicators in the CCAT detected this suboptimal effort with exception sensitivity. Acceptable results on CCAT baseline testing reflect tests where subjects were not malingering.Competing interestsDrs Maruff and Cromer are full time employees of CogState, Ltd, manufacturer of the Axon Sports CCAT.
School problems following sports concussion. Which children are at greatest risk?
Authors: Vaughan Christopher , Gioia Gerard , Sady Maegan 
Published: March 2013

ObjectiveIdentify risk for adverse outcomes in school performance and attendance following concussion.DesignCorrelational.SettingOutpatient clinic, teaching hospital.Participants216 children ages 12–18 (mean (SD)=15.1 (1.6); 70% male) seen within 2 months of sport-related concussion (mean days since injury=21.2 (12.6)).InterventionsPredictors: Pre-injury risk/post-concussion symptoms, injury characteristics.Main Outcome MeasurementsReported drop in grades, days of school absence.ResultsCorrelation and crosstabs revealed no association between a drop in grades and a personal or family history of developmental delays, pre-injury school performance, developmental disabilities, or previous concussions. Higher maternal education and retrospective pre-injury symptoms were significantly associated with lower grades. Total post-injury symptom burden (parent and child reported) and physical exertional symptoms were not related, although presence of amnesia/loss of consciousness and cognitive exertional effects (symptom exacerbation) were significantly associated with lower grades. No pre-injury risk factors were correlated with school absence, but symptom burden at time of injury and subsequent parent/child symptom report at time of evaluation were positively associated with number of days absent from school.ConclusionsVarying post-concussion factors are related to school outcomes. Pre-injury risk factors (higher baseline symptoms, maternal education) and post-injury factors (LOC/amnesia, cognitive exertional effects) related to drop in grades. In contrast, symptom burden at injury and later severity was related to days absent from school. These findings provide the clinician with useful indicators of possible risk factors for adverse outcomes in school performance, an important issue in concussion management for children.Competing interestsNone.
Sport concussion assessment tool-2 (SCAT2) scores in the acute phase following concussion in high school athletes
Authors: Mayfield Richelle M , Shepherd Lindsey , Valovich McLeod Tamara C , Curtis Bay R 
Published: March 2013

ObjectiveTo investigate changes in SCAT2 scores in high school athletes in the first 10 days post-concussion.DesignWithin subjects, repeated measures.SettingHigh school athletic facilities.Patients119 high school athletes who sustained a sport-related concussion diagnosed by their athletic trainer (102 males, 15 females, and 2 missing, age=15.8±1.2, grade=10.0±1.0 level).InterventionsThe SCAT2 was administered during a preseason baseline, day of injury (DOI), and days 3 (D3) and 10 (D10) post-concussion. The SCAT2 total score is calculated by summing each component score, and has a maximum of 100 points.Main Outcome MeasuresDay of testing served as the independent variable and the dependent variable was SCAT2 total score. Analyses were conducted using a generalised estimating equations approach to accommodate repeated measures of the same participants. An inverse Gaussian distribution and identity link were specified, along with robust variance estimators. Follow-up pairwise tests employed a Bonferroni correction.ResultsThe omnibus test was significant (p<0.001). Scores at DOI (73.5, 95% CI 70.8 to 76.1) were significantly lower than BL (86.0, 95% CI 84.8 to 87.3). D3 scores (79.8, 95% CI 77.2 to 82.3) remained significantly lower than BL, but were significantly higher than DOI. Scores at D10 (88.8, 95% CI 87.3 to 90.3) were significantly higher than DOI, D3, and BL.ConclusionsSCAT2 scores decreased significantly during the first 3 days post-concussion, demonstrating impairments in a composite score that includes symptoms, mental status, and balance. Deficits in the SCAT2 recovered to levels above baseline by D10, indicating a resolution of concussion related impairments.AcknowledgementsThis study was funded by a grant from the National Operating Committee for Standards on Athletic Equipment (NOCSAE).Competing interestsNone.
Exploring parent and youth perspectives of the influence of concussion on school, sport and life: a qualitative study
Authors: Provvidenza Christine , Keightley Michelle L , Reed Nick , Green Stephanie 
Published: March 2013

ObjectiveThe purpose of this qualitative study was to describe the perceived impact of sports-related concussion by youth and their parents on home, school and sport functioning.DesignSemi-structured interviews were used to assess perceived changes in general academic ability, attention, learning difficulties, social performance, behaviour, mood and emotions, executive and physical function. Framework analysis was used to analyse and interpret the data.SettingParticipants were purposively recruited from a longitudinal study investigating the cognitive and physical effects of sports-related concussion in children from 2007–2010.Subjects13 child athletes (11 males and 2 females; average age=11±0.856 years) ages 10–13 years and their parents (13 parents=9 mothers and 4 fathers).InterventionNone.Outcome MeasuresInterviews were recorded and transcribed verbatim. Framework analysis was employed to identify emerging themes.ResultsThe theme ‘a journey of recovery from concussion across time’ was identified and encompassed: initial reaction and recovery, re-integration into sport and school, evolvement of life skills, performance related to school and sports, personality and behaviour changes, and life lessons learned.ConclusionsNo long term impact of concussion was reported on hockey or school performance, but higher levels of anger and frustration related to performance post-injury were found. Child athletes' comments indicated fear of being hit again when returning to play, and a return to play while symptomatic. This suggests the need for further education around the definition of concussion and recovery, and follow-up support during return to play.AcknowledgementsOntario Neurotrauma Foundation.Competing interestsNone.
Working memory in youth following sports-related concussion: is it still working? an fMRI study
Authors: Keightley Michelle L , Saluja Rajeet Singh , Chen Jen-Kai , Ptito Alain , Gagnon Isabelle 
Published: March 2013

ObjectiveTo compare working memory performance and related brain activity using fMRI in concussed youth and healthy age-matched control subjects.DesignStandard T1and T2* weighted echo planar images for blood oxygenation level dependent (BOLD) were collected on a 3Tesla System with a 32 channel head coil while subjects performed verbal and nonverbal working memory tasks. fMRIstat was used to analyse the data.SettingParticipants were purposively recruited between 2007 and 2010 from The Montreal Children's Hospital Trauma Programs.Subjects15 concussed youth (8 females, 7 males, mean age=14.47±2.29 years) and 15 age-matched control subjects (7 females, 8 males, mean age=14±2.3 years).InterventionNone.Outcome MeasuresPost-Concussion Scale—Revised, accuracy and reaction time (RT) on a verbal and nonverbal working memory task.ResultsPost-concussion symptoms were higher for concussed versus control participants. The concussed group demonstrated significantly poorer accuracy but equivalent RT on the working memory task. Greater percent BOLD signal change from baseline to task was observed for control versus concussed participants in the left and right dorsolateral prefrontal cortex, left premotor cortex, dorsal anterior cingulate cortex, supplementary motor area, left superior parietal lobule, left thalamus and left caudate nucleus. Activity in the left and right dorsolateral prefrontal cortices positively correlated with task accuracy.ConclusionsCompared to adults, concussed youth may be unable to engage to the same extent compensatory strategies to maintain cognitive performance following neuronal injury. Greater caution in clinical management is therefore recommended.AcknowledgementsCanadian Institute of Health Research (CIHR) and Ontario Neurotrauma Foundation (ONF).Competing interestsNone.