bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Characterization of IncI2 Plasmids Carrying
bla
CTX-M-55
Spreading in both Pets and Food Animals in China
Authors: Lv Luchao , Partridge Sally R. , He Liangying , Zeng Zhenling , He Dandan , Ye Jiahui , Liu Jian-Hua
Published: March 2013

pHN1122-1 carrying
bla
CTX-M-55
, from an
Escherichia coli
isolate from a dog, was completely sequenced. pHN1122-1 has an IncI2 replicon and typical IncI2-associated genetic modules, including
mok
/
hok-finO-yafA
/
B
,
nikABC
, and two transfer regions,
tra
and
pil
, as well as a shufflon.
bla
CTX-M-55
is found within a 3.084-kb IS
Ecp1
transposition unit that includes a fragment of IncA/C plasmid backbone. pHN1122-1 and closely related plasmids were identified in other
E. coli
isolates from animals in China.
Efficacy of Repeated Intravenous Injection of Peramivir against Influenza A (H1N1) 2009 Virus Infection in Immunosuppressed Mice
Authors: Kitano Mitsutaka , Kodama Makoto , Itoh Yasushi , Kanazu Takushi , Kobayashi Masanori , Yoshida Ryu , Sato Akihiko
Published: March 2013

The efficacy of intravenous peramivir against influenza A (H1N1) 2009 virus infection was evaluated in mice in which the immune system was suppressed by cyclophosphamide (CP) treatment. The mortality rate of the vehicle control group was 100%, and the mice lost 20% of their body weight on average by day 13 postinfection (p.i.). Repeated administration of peramivir (40 mg/kg of body weight once a day, given intravenously for 20 days), starting at 1 h p.i., significantly reduced mortality, body weight loss, viral titers, and cytokine production in infected mice compared with results for administration of vehicle (
P
< 0.01). In addition, repeated administration of peramivir, starting at 24 h, 48 h, or 72 h p.i., also resulted in increases in survival rates and reduction of viral titers in the lungs (
P
< 0.01). The mean days to death (MDD) of the vehicle group was 14.5 days, while in the groups treated with peramivir starting at 24 h, 48 h, and 72 h p.i., the MDDs were >23.0, 20.9, and 21.8 days, respectively. In comparison, repeated administration of oseltamivir phosphate (5 mg/kg twice a day, given orally for 20 days), starting at 24 h, 48 h, and 72 h p.i., also significantly prevented body weight loss, whereas no significant differences in mortality rates and viral titers in the lungs were observed compared with results for the vehicle group. These data indicated that repeated administration of peramivir was effective in promoting the survival and reducing virus replication in immunosuppressed mice infected with influenza A (H1N1) 2009 virus.
Pharmacodynamic Evaluation of the Intracellular Activity of Antibiotics towards Pseudomonas aeruginosa PAO1 in a Model of THP-1 Human Monocytes
Authors: Buyck Julien M. , Tulkens Paul M. , Van Bambeke Françoise
Published: March 2013

Pseudomonas aeruginosa
invades epithelial and phagocytic cells, which may play an important role in the persistence of infection. We have developed a 24-h model of THP-1 monocyte infection with
P. aeruginosa
PAO1 in which bacteria are seen multiplying in vacuoles by electron microscopy. The model has been used to quantitatively assess antibiotic activity against intracellular and extracellular bacteria by using a pharmacodynamic approach (concentration-dependent experiments over a wide range of extracellular concentrations to calculate bacteriostatic concentrations [
C
s
] and maximal relative efficacies [
E
max
]; Hill-Langmuir equation). Using 16 antipseudomonal antibiotics (three aminoglycosides, nine β-lactams, three fluoroquinolones, and colistin), dose-response curves were found to be undistinguishable for antibiotics of the same pharmacological class if data were expressed as a function of the corresponding MICs. Extracellularly, all of the antibiotics reached a bacteriostatic effect at their MIC, and their
E
max
exceeded the limit of detection (−4.5 log
10
CFU compared to the initial inoculum). Intracellularly,
C
s
values remained unchanged for β-lactams, fluoroquinolones, and colistin but were approximately 10 times higher for aminoglycosides, whereas
E
max
values were markedly reduced (less negative), reaching −3 log
10
CFU for fluoroquinolones and only −1 to −1.5 log
10
CFU for all other antibiotics. The decrease in intracellular aminoglycoside potency (higher
C
s
) can be ascribed to the acid pH to which bacteria are exposed in vacuoles. The decrease in the
E
max
may reflect a reversible alteration of bacterial responsiveness to antibiotics in the intracellular milieu. The model may prove useful for comparison of antipseudomonal antibiotics to reduce the risk of persistence or relapse of pseudomonal infections.
Role of Ficolin-A and Lectin Complement Pathway in the Innate Defense against Pathogenic Aspergillus Species
Authors: Bidula Stefan , Kenawy Hany , Ali Youssif M. , Sexton Darren , Schwaeble Wilhelm J. , Schelenz Silke
Published: March 2013

Aspergillusspecies are saprophytic molds causing life-threatening invasive fungal infections in the immunocompromised host. Innate immune recognition, in particular, the mechanisms of opsonization and complement activation, has been reported to be an integral part of the defense against fungi. We have shown that the complement component ficolin-A significantly binds toAspergillusconidia and hyphae in a concentration-dependent manner and was inhibited byN-acetylglucosamine andN-acetylgalactosamine. Calcium-independent binding toAspergillus fumigatusandA. terreuswas observed, but binding toA. flavusandA. nigerwas calcium dependent. Ficolin-A binding to conidia was increased under low-pH conditions, and opsonization led to enhanced binding of conidia to A549 airway epithelial cells. In investigations of the lectin pathway of complement activation, ficolin-A-opsonized conidia did not lead to lectin pathway-specific C4 deposition. In contrast, the collectin mannose binding lectin C (MBL-C) but not MBL-A led to efficient lectin pathway activation onA. fumigatusin the absence of ficolin-A. In addition, ficolin-A opsonization led to a modulation of the proinflammatory cytokine interleukin-8. We conclude that ficolin-A may play an important role in the innate defense againstAspergillusby opsonizing conidia, immobilizing this fungus through enhanced adherence to epithelial cells and modulation of inflammation. However, it appears that other immune pattern recognition molecules, i.e., those of the collectin MBL-C, are involved in theAspergillus-lectin complement pathway activation rather than ficolin-A.
Study of the Response Regulator Rrp1 Reveals Its Regulatory Role in Chitobiose Utilization and Virulence of Borrelia burgdorferi
Authors: Sze Ching Wooen , Smith Alexis , Choi Young Hee , Yang Xiuli , Pal Utpal , Yu Aiming , Li Chunhao
Published: March 2013

Life cycle alternation between arthropod and mammals forces the Lyme disease spirochete,
Borrelia burgdorferi
, to adapt to different host milieus by utilizing diverse carbohydrates. Glycerol and chitobiose are abundantly present in the
Ixodes
tick.
B. burgdorferi
can utilize glycerol as a carbohydrate source for glycolysis and chitobiose to produce
N
-acetylglucosamine (GlcNAc), a key component of the bacterial cell wall. A recent study reported that Rrp1, a response regulator that synthesizes cyclic diguanylate (c-di-GMP), governs glycerol utilization in
B. burgdorferi
. In this report, we found that the
rrp1
mutant had growth defects and formed membrane blebs that led to cell lysis when GlcNAc was replaced by chitobiose in the growth medium. The gene
chbC
encodes a key chitobiose transporter of
B. burgdorferi
. We found that the expression level of
chbC
was significantly repressed in the mutant and that constitutive expression of
chbC
in the mutant successfully rescued the growth defect, indicating a regulatory role of Rrp1 in chitobiose uptake. Immunoblotting and transcriptional studies revealed that Rrp1 is required for the activation of
bosR
and
rpoS
and that its impact on
chbC
is most likely mediated by the BosR-RpoS regulatory pathway. Tick-mouse infection studies showed that although the
rrp1
mutant failed to establish infection in mice via tick bite, exogenous supplementation of GlcNAc into unfed ticks partially rescued the infection. The finding reported here provides us with new insight into the regulatory role of Rrp1 in carbohydrate utilization and virulence of
B. burgdorferi
.
Predominant Role of Host Proteases in Myocardial Damage Associated with Infectious Endocarditis Induced by Enterococcus faecalis in a Rat Model
Authors: Augustin Pascal , Alsalih Ghada , Launey Yoann , Delbosc Sandrine , Louedec Liliane , Ollivier Véronique , Chau Françoise , Montravers Philippe , Duval Xavier , Michel Jean-Baptiste , Meilhac Olivier
Published: March 2013

Infective endocarditis (IE) remains a life-threatening infectious disease with high morbidity and mortality. The objectives of the present study are to assess the host proteolytic activities of the vegetations and their cytotoxic potential in a rat model of experimental IE. Rats were infected with a strain of
Enterococcus faecalis
of particularly low virulence and weak protease expression. We tested the presence of proteases released by infiltrated leukocytes (matrix metalloproteinases and elastase) or produced
in situ
within the septic vegetation, such as those linked to the fibrinolytic system (plasmin and plasminogen activators). We also assessed the tissue damage induced by the infective thrombus
in vitro
and
ex vivo
. The model of IE was characterized by larger and more extensive vegetations in infected than in nonseptic rats and by an intense neutrophil infiltrate interfacing with the injured underlying tissue. Neutrophil extracellular DNA was shown to trap bacteria and to produce increased levels of cell-free DNA in plasma. Matrix metalloproteinase-9, elastase, and plasminogen activators were increased in septic versus nonseptic vegetations (as shown by zymography and immunohistology). Finally, proteolysis of the extracellular matrix and apoptosis were shown to be associated with host proteases. Bacteria exhibited no detectable proteolytic activity or direct cytotoxic effects. Bacterial membranes/dead bacteria were sufficient to induce leukocyte recruitment and activation that could promote vegetation formation and growth. Our results suggest that, despite the lack of bacterial proteases, the continuous attractant signals coming from bacterial colonies may lead to a chronic and deleterious aggression toward myocardial/valvular tissues by host proteases.
Expression and Function of Psoriasin (S100A7) and Koebnerisin (S100A15) in the Brain
Authors: Jansen Sandra , Podschun Rainer , Leib Stephen L. , Grötzinger Joachim , Oestern Stefanie , Michalek Matthias , Pufe Thomas , Brandenburg Lars-Ove
Published: March 2013

The expression and function of psoriasin in the brain have been insufficiently characterized. Here, we show the induction of psoriasin expression in the central nervous system (CNS) after bacterial and viral stimulation. We used a pneumococcal meningitis
in vivo
model that revealed S100A15 expression in astrocytes and meningeal cells. These results were confirmed by a cell-based
in vivo
assay using primary rat glial and meningeal cell cultures. We investigated psoriasin expression in glial and meningeal cells using polyinosinic-polycytidylic acid, a synthetic analog of double-stranded RNA that mimics viral infection. Furthermore, previous results showed that antimicrobial peptides have not only bactericidal but also immunomodulatory functions. To test this statement, we used recombinant psoriasin as a stimulus. Glial and meningeal cells were treated with recombinant psoriasin at concentrations from 25 to 500 ng/ml. Treated microglia and meningeal cells showed phosphorylation of the extracellular signal-regulated kinase 1 (ERK1)/ERK2 (ERK1/2) signal transduction pathway. We demonstrated that this activation of ERK depends on RAGE, the receptor for advanced glycation end products. Furthermore, microglia cells treated with recombinant psoriasin change their phenotype to an enlarged shape. In conclusion, our results indicate an occurrence of psoriasin in the brain. An involvement of psoriasin as an antimicrobial protein that modulates the innate immune system after bacterial or viral stimulation is possible.
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

Escherichia 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

Objective

The 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.

Design

In 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.

Settings

Research center (CRO). Clinical care not applicable.

Participants

Healthy volunteers of both genders aged 18–45 years. Fifteen participants were enrolled, 13 completed the study.

Interventions

0.4 mg of scopolamine was administered subcutaneously.

Main Outcome Measurements

Brain 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.

Results

A 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).

Conclusions

Pharmacologically 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

Objective

To 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.

Design

Cross-sectional.

Setting

Community ice rinks and sport medicine clinic in Calgary, Alberta, Canada.

Participants

532 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 Measurements

458 players completed preseason tests of CFE, WWTT and cDVA (2011/12 hockey season).

Results

Multivariate 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).

Conclusions

Tasks 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.

Acknowledgements

The 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

Objective

To investigate associations ofAPOEandTaugene polymorphisms with sports-related acute concussions and baseline to post-concussion neuropsychological test score changes.

Design

Multi-center prospective cohort study.

Setting

Scholarship athletes at 21 universities and 4 high schools Participants: 3218 athletes playing football (70%) or soccer (23%).

Assessment of Risk Factors

APOE,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.

Results

There 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).

Conclusions

The 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.

Acknowledgements

Grant 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 interests

None.
Concussions in National Hockey League (NHL) players: 5-year video analysis
Authors: Hutchison Michael , Comper Paul
Published: March 2013

Objectives

To understand, through video analysis, how playing characteristics and mechanism of injury contribute to concussions in the National Hockey League (NHL).

Setting

National Hockey League.

Design

Prospective case series of concussions over a 5 year period of regular season NHL games (2006–2011).

Subjects

Digital video images of 341 diagnosed concussions of NHL players.

Outcome Measures

Concussions 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.

Results

During 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.

Conclusions

Based 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 interests

One 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

Objective

To develop an observational tool to reliably code the situational characteristics and mechanism of contact for fights ending in knockout (KO) or technical KO (TKO).

Design

Digital video images and fight card information were collected retrospectively for UFC events during 2006–2009.

Subjects

Two 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 Measures

The 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.

Results

Coders 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.

Conclusion

The MMA ‘Knockout’ Tool is reliable for coding the situational characteristics and mechanism of contact(s) for fights ending in a TKO or KO.

Acknowledgements

The Canadian Institutes of Health Research (CIHR) Strategic Team in Applied Injury Research funded this research

Competing interests

None.
Detecting suboptimal effort in concussion management settings with the axon sports CCAT
Authors: Louey Andrea G , Maruff Paul , Cromer Jason A
Published: March 2013

Objective

Accurate 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.

Design

Within-subject, randomised, with Optimal and Feigned impairment conditions.

Setting

Cognitive testing with the CCAT was completed at a university clinic.

Subjects

A healthy adult sample aged between 16 and 30 years.

Intervention

Subjects 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 Measurements

Mean 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.

Results

Subjects 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.

Conclusions

Identifiable 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 interests

Drs 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

Objective

Identify risk for adverse outcomes in school performance and attendance following concussion.

Design

Correlational.

Setting

Outpatient clinic, teaching hospital.

Participants

216 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)).

Interventions

Predictors: Pre-injury risk/post-concussion symptoms, injury characteristics.

Main Outcome Measurements

Reported drop in grades, days of school absence.

Results

Correlation 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.

Conclusions

Varying 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 interests

None.
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

Objective

To investigate changes in SCAT2 scores in high school athletes in the first 10 days post-concussion.

Design

Within subjects, repeated measures.

Setting

High school athletic facilities.

Patients

119 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).

Interventions

The 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 Measures

Day 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.

Results

The 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.

Conclusions

SCAT2 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.

Acknowledgements

This study was funded by a grant from the National Operating Committee for Standards on Athletic Equipment (NOCSAE).

Competing interests

None.
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

Objective

The 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.

Design

Semi-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.

Setting

Participants were purposively recruited from a longitudinal study investigating the cognitive and physical effects of sports-related concussion in children from 2007–2010.

Subjects

13 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).

Intervention

None.

Outcome Measures

Interviews were recorded and transcribed verbatim. Framework analysis was employed to identify emerging themes.

Results

The 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.

Conclusions

No 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.

Acknowledgements

Ontario Neurotrauma Foundation.

Competing interests

None.
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

Objective

To compare working memory performance and related brain activity using fMRI in concussed youth and healthy age-matched control subjects.

Design

Standard 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.

Setting

Participants were purposively recruited between 2007 and 2010 from The Montreal Children's Hospital Trauma Programs.

Subjects

15 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).

Intervention

None.

Outcome Measures

Post-Concussion Scale—Revised, accuracy and reaction time (RT) on a verbal and nonverbal working memory task.

Results

Post-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.

Conclusions

Compared 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.

Acknowledgements

Canadian Institute of Health Research (CIHR) and Ontario Neurotrauma Foundation (ONF).

Competing interests

None.
Frequency of and responses to illegal activity related to commerce in firearms: findings from the Firearms Licensee Survey
Authors: Wintemute Garen J
Published: March 2013

Background

Firearms may be obtained illegally from federally-licensed dealers and pawnbrokers through surrogate (straw) purchases, undocumented purchases and theft. Some retailers knowingly make illegal sales.

Objective

To obtain information about the frequency of and risk factors for these events, and retailers’ reactions to them, directly from licensed retailers.

Methods

Survey of a random sample of 1601 licensed dealers and pawnbrokers in 43 states who were believed to sell ≥50 firearms annually, conducted by mail during June–August 2011.

Results

The response rate was 36.9%, typical of establishment surveys using such methods. In the preceding year, 67.3% of respondents experienced attempted straw purchases; 42.4% experienced undocumented purchase attempts. For each event, 10% reported ≥1 occurrence/month. A quarter (25.6%) experienced firearm theft in the preceding 5 years. Pawnbroker status, sales volume, denied sales and sales of firearms that were subsequently traced by law enforcement were associated with all outcomes in multivariate analysis. Estimates of retailer involvement in illegal sales (median 3%, IQR 1–10%) were related in multivariate analysis to respondents’ age and sex, and to denied sales. In a hypothetical case involving 50 illegal sales, respondents recommended prolonged incarceration (median 10 years, IQR 5–20 years) and a substantial fine (median $50 000, IQR $10 000–$250 000) for retailers and made similar recommendations for buyers.

Conclusions

Attempts to acquire firearms illegally from licensed dealers and pawnbrokers are common. Characteristics associated with frequency of occurrence may facilitate prevention efforts. Licensed retailers consider selling and buying firearms illegally to be serious crimes.
Retinol binding protein 4 affects the adipogenesis of porcine preadipocytes through insulin signaling pathways
Authors: Cheng Jia , Song Zi-Yi , Pu Lei , Yang Hao , Zheng Jia-Meng , Zhang Zhen-Yu , Shi Xin-E. , Yang Gong-She
Published: March 2013

Retinol binding protein 4 (RBP4), a novel cytokine, is mainly secreted by hepatocytes and adipocytes. RBP4 reportedly induces insulin resistance and RBP4 secretion is increased in the adipocytes of animals or humans with type 2 diabetes, obesity, and metabolic syndrome, but its role in preadipocyte differentiation remains unclear. In this study, we investigated the effect of RBP4 on the differentiation of porcine preadipocytes into adipocytes. The results suggest that RBP4 significantly suppresses the differentiation of porcine preadipocytes into adipocytes, including those treated with the hormone cocktail methylisobutylxanthine–dexamethasone–insulin. RBP4 also weakened the activity of normal threonine 308, the phosphorylation of serine/threonine kinase AKT, and downstream insulin signaling, including the mammalian target of rapamycin (mTOR) and β-catenin. Moreover, the activation of insulin signaling mediated by knockdown RBP4 in porcine preadipocytes was recovered in the suppression of LY294002. RBP4 also had a suppressive effect on the differentiation of porcine preadipocytes by decreasing the activation of insulin signaling pathways.
A heuristic method to determine optimum degree of activity accelerating and overlapping in schedule compression
Authors: Hazini Kamran , Dehghan Reza , Ruwanpura Janaka
Published: March 2013

Schedule compression is an attempt to reduce project durations for early delivery, or to catch up on occurred delays. This is usually performed using “crashing”, “overlapping” and “substitution” of activities. “Crashing” is shortening task duration by adding more resource hours. “Substitution” is changing the method or tool by which the activity is performed. “Overlapping” is performing sequential activities in parallel. Few studies can be found in the literature that compare costs and benefits of each technique and recommend the optimum combination of these techniques in project schedules. In fact, the implications of each technique are inherently different since crashing and substitution impose extra cost whereas overlapping adds the risk of changes and rework. Therefore, it is a challenge to develop a reliable analytical tool for performing time–cost trade-offs using the three methods. There are also few studies in the literature to propose a practical method for performing schedule compression by combining these techniques. The purpose of this paper is to discuss these schedule compression techniques in detail, and present and validate a heuristic method to perform the combination of crashing, overlapping and substitution in a project schedule, to reach the maximum benefit while meeting the project target dates.
Giant Upper Triassic bivalves of Wrangellia, Vancouver Island, Canada
Authors: Stanley George D. , Yancey Thomas E. , Shepherd Hannah M.E.
Published: March 2013

One of the most distinctive components of the Late Triassic warm-water biota are alatoform, reclining bivalves of the genus Wallowaconcha. Wallowaconcha raylenea was first described from shallow-water, fine-grained Upper Triassic carbonate rocks of the Wallowa terrane, northeastern Oregon, and later found in coeval limestone in the Yukon. Fossils of the family Wallowaconchidae are easily recognized and readily distinguished from other fossil groups by their large size (over a metre in length), alatoform morphology, and especially the chambered wing-like extensions likely associated with photosymbiosis. Several different taxa of Norian age inhabited lagoon and reef-related settings on four separate terranes of western North America (Antimonio terrane, Sonora, Mexico; Wallowa terrane, northeastern Oregon; Stikine terrane in the Yukon; Chulitna terrane of Alaska), which during Triassic time existed as volcanic islands in the eastern Panthalassa Ocean. Outside eastern Panthalassa in the eastern Tethys, two other species of Wallowaconcha come from distant localities in Asia and Arabia. We here report for the first time, in presumed Rhaetian limestone of the upper part of the Parson Bay Formation, Vancouver Island, newly discovered examples of Wallowaconcha. They are from Wrangellia and, based on size and shape of the chambers, are assignable to W. raylenea but unlike other examples they appear to be Rhaetian in age. This species of giant bivalve inhabited warm-water locales outboard of North America during the Late Triassic, and its presence provides possible paleobiogeographic links of Wrangellia with both Stikinia and the Wallowa terrane.
Isolation and characterization of a rare waterborne lytic phage of Salmonella enterica serovar Paratyphi B
Authors: Ahiwale Sangeeta S. , Bankar Ashok V. , Tagunde Sujata N. , Zinjarde Smita , Ackermann Hans W. , Kapadnis B.P.
Published: March 2013

A lytic phage of Salmonella serovar Paratyphi B, named φSPB, was isolated from surface waters of the Pavana River in India. Phage φSPB is a member of the Podoviridae family and is morphologically similar to the 7-11 phages of the C3 morphotype of tailed phages, characterized by a very long, cigar-shaped head. The head measured approximately 153 × 57 nm, and the tail size was 12 × 7 nm. The phage was stable over a wide range of pH (4–9) and temperature (4–40 °C). The adsorption rate constant was 4.7 × 10−10. Latent and eclipse periods were 10 and 15 min, respectively, and the burst size was 100 plaque-forming units/infected cell after 25 min at 37 °C. The phage DNA was 59 kb in size. Ten major proteins were observed on SDS–PAGE, although some of these proteins could be bacterial contaminants. This is the first report of Salmonella enterica subsp. enterica serovar Paratyphi B phage of C3 morphotype from India that has many unique features, such as high replication potential, short replication time, and stability over a wide range of pH and temperature, making it a promising biocontrol agent against the drug-resistant strains of Salmonella Paratyphi B.
Diversity of bacterial community during spring phytoplankton blooms in the central Yellow Sea
Authors: Liu Min , Dong Yi , Zhang Wuchang , Sun Jun , Zhou Feng , Ren Jingling , Bao Shixiang , Xiao Tian
Published: March 2013

Bacterial community diversity and the effects of environmental factors on bacterial community composition during 2 spring phytoplankton blooms in the central Yellow Sea were investigated by using denaturing gradient gel electrophoresis (DGGE) and multivariate statistical analysis. The Shannon–Weaver indices (H′) of bacterial diversity from samples at station B23 were higher than those at station B20. Cluster analysis based on DGGE band patterns indicated temporal variations of bacterial community at the 2 bloom stations but a vertical distribution pattern only at station B20. The predominant bacterial groups were affiliated with Alphaproteobacteria, Gammaproteobacteria, Cytophaga–Flavobacterium–Bacteroides, Deltaproteobacteria, and Actinobacteria. The effects of environmental factors on bacterial community were analyzed by canonical correspondence analysis. Bacterial community structures were significantly affected by silicate at station B20 and by Paralia sulcata and Heterocapsa spp. at station B23. From the results, phytoplankton species composition had a significant effect on bacterial community structure during phytoplankton blooms in the central Yellow Sea.
A SECTION APPROACH TO A TRAFFIC FLOW MODEL ON NETWORKS
Authors: GUPTA ARVIND KUMAR
Published: March 2013

The development of real time traffic flow models for urban road networks is of paramount importance for the purposes of optimizing and control of traffic flow. Motivated by the modeling of road networks in last decade, this paper proposes a different and simplified approach, known as section approach to model road networks in the framework of macroscopic traffic flow models. For evaluation of the traffic states on a single road, an anisotropic continuum GK-model developed by [Gupta and Katiyar, J. Phys. A38, 4069 (2005)] is used as a single-section model. This model is applied to a two-section single lane road with points of entry and exits. In place of modeling the effect of off- and on-ramps in the continuity equation, a set of special boundary condition is taken into account to treat the points of entry and exit. A four-section road network comprised of two one-lane roads is also modeled using this methodology. The performances of the section approaches are investigated and obtained results are demonstrated over simulated data for different boundary conditions.
THE APPLICATION OF AN ENDOGENOUS POVERTY LINE AND ITS RELATIONSHIP WITH THE POVERTY IMPACT OF ECONOMIC SHOCKS: AN EMPIRICAL INVESTIGATION
Authors: DARTANTO TEGUH
Published: March 2013

Most of the studies on the poverty impact of economic shocks as well as policy reforms assumed the poverty line as a fixed line; thus, the poverty outcome of shocks may underestimate (overestimate) and mislead in policy guidance. This research aims at empirically investigating the difference of poverty outcome between applying a fixed and an endogenous poverty line. Applying computable general equilibrium microsimulation (CGE-MS), this study has empirically proven that, if a fixed poverty line is applied, the poverty impact of economic shocks which significantly increase (decrease) price will always be underestimated (overestimated). This study empirically found that there is a 0.316 percentage point difference in the poverty outcome between applying the endogenous poverty line and the fixed poverty line when analyzing the impact on poverty in Indonesia of a doubling in the imported soybean price. Supposing the fixed poverty line, the poverty rate will increase by 0.167 percentage points, while supposing the endogenous poverty line, the poverty rate will increase by 0.483 percentage points. Therefore, applying either an endogenous or a fixed poverty line will have a different policy implication. This study strongly suggested that the endogenous poverty line should be applied when analyzing the poverty impact of shocks due to the precision in outcomes.