bluuebunny/crossref_metadata_2025_split huggingface dataset:
Entry of human cytomegalovirus into porcine endothelial cells depends on both the cellular vascular origin and the viral strain
Authors: Taveira Aline , Ponroy Nicolas , Mueller Nicolas J. , Millard Anne‐Laure 
Published: April 2014

AbstractBackgroundPrimary infection and reactivation of human cytomegalovirus (HCMV) is associated with allograft rejection. Pig‐to‐human xenotransplantation is regarded as an alternative to circumvent donor organ shortage and inevitably, porcine endothelial cells (pEC) will be exposed to human pathogens, among them HCMV. Infection of pEC with HCMV induces apoptosis and entry is sufficient to induce phenotypic alterations, which have the potential to result in rejection and vasculopathy. We investigated the mechanisms used by HCMV to enter pEC from different anatomical origins and compared them with the entry mechanisms used to enter human endothelial cells (hEC).MethodsImmortalized porcine aortic (PEDSV.15) and porcine microvascular bone marrow derived EC (2A2) as well as primary human aortic (HAEC) and microvascular EC (HMVEC) were inoculated with the endotheliotropic (TB40/E) or the fibroblast propagated (TB40/F) HCMV strains at multiplicity of infection (MOI) ranging from 0.3 to 5. EC were analyzed for receptor expression and their involvement in HCMV entry. The role of endocytosis was evaluated by treating EC with specific inhibitors, and the involvement of the endolysosomal pathway was investigated by confocal microscopy.ResultsSilencing of platelet‐derived growth factor receptor alpha resulted in a reduced expression of viral immediate early (IE) antigen only in pEC infected with either TB40/E or TB40/F whereas silencing of β1 integrins reduced expression of IE proteins in all EC except for TB40/F‐infected microvascular pEC. TB40/E enters hEC and pEC by a similar mechanism dependent on dynamin‐2, lipid rafts, actin and pH, whereas entry of TB40/F in pEC occurs mainly by a dynamin‐2‐dependent, clathrin‐, lipid rafts‐independent mechanism and in a pH‐dispensable manner. When actin polymerization was prevented, TB40/F could enter pEC in an actin‐independent fashion. Disturbance of the microtubule cytoskeleton resulted in an inhibition of infection of TB40/E‐infected EC, whereas infection of TB40/F‐infected pEC was not modified. Finally, viral particles located in vesicles of the endolysosomal pathway, suggesting that HCMV uses this pathway for intracellular trafficking following entry.ConclusionsOur findings demonstrate that HCMV uses a variety of entry mechanisms that are dependent on the strain and on the vascular origin of the cells. Given the profound effect of pEC infection with HCMV, prevention of such an infection will be crucial for clinical application of xenotransplantation. A potential avenue is to render porcine grafts resistant to HCMV infection by blocking viral entry and propagation.
Insulin modulates network activity in olfactory bulb slices: impact on odour processing
Authors: Kuczewski Nicola , Fourcaud‐Trocmé Nicolas , Savigner Agnès , Thevenet Marc , Aimé Pascaline , Garcia Samuel , Duchamp‐Viret Patricia , Palouzier‐Paulignan Brigitte 
Published: April 2014

Key points
Olfactory function is largely under metabolic influence.
Insulin, one of the major players between food intake and energy balance, is known to act at both central and peripheral levels.
The present study assesses the action of insulin in olfactory bulb slices by using patch‐clamp recordings in young rats.
The results show that insulin can alter both spontaneous and olfactory nerve‐induced firing activities in most of the main ouput neurons, this action being differentially exerted in two opposite directions.
A mathematical model demonstrates that insulin, by acting in this way, could impact odour detection and discrimination mechanisms. Such an impact could be hypothesized as being exerted according to pertinent ecological characteristics, such as the alimentary/ethological valence of odour.
AbstractOdour perception depends closely on nutritional status, in animals as in humans. Insulin, the principal anorectic hormone, appears to be one of the major candidates for ensuring the link between olfactory abilities and nutritional status, by modifying processing in the olfactory bulb (OB), one of its main central targets. The present study investigates whether and how insulin can act in OB, by evaluating its action on the main output neurons activities, mitral cells (MCs), in acute rat OB slices. Insulin was found to act at two OB network levels: (1) on MCs, by increasing their excitability, probably by inhibiting two voltage‐gated potassium (K+) channels; (2) on interneurons by modifying the GABAergic and on glutamatergic synaptic activity impinging on MCs, mainly reducing them. Insulin also altered the olfactory nerve (ON)‐evoked excitatory postsynaptic currents in 60% of MCs. Insulin decreased or increased the ON‐evoked responses in equal proportion and the direction of its effect depended on the initial neuron ON‐evoked firing rate. Indeed, insulin tended to decrease the high and to increase the low ON‐evoked firing rates, thereby reducing inter‐MC response firing variability. Therefore, the effects of insulin on the evoked firing rates were not carried out indiscriminately in the MC population. By constructing a mathematical model, the impact of insulin complex effects on OB was assessed at the population activity level. The model shows that the reduction of variability across cells could affect MC detection and discrimination abilities, mainly by decreasing and, less frequently, increasing them, depending on odour quality. Thus, as previously proposed, this differential action of insulin on MCs across odours would allow this hormone to put the olfactory function under feeding signal control, given the discerning valence of an odour as a function of nutritional status.
Transient impairment of the axolemma following regional anaesthesia by lidocaine in humans
Authors: Moldovan Mihai , Lange Kai Henrik Wiborg , Aachmann‐Andersen Niels Jacob , Kjær Troels Wesenberg , Olsen Niels Vidiendal , Krarup Christian 
Published: April 2014

Key points
We tested the recovery of motor axon conduction and multiple measures of excitability by ‘threshold‐tracking’ after ultrasound‐guided distal median nerve regional anaesthesia by lidocaine.
Lidocaine caused a transient conduction failure that recovered completely by 3 h, whereas excitability recovered only partially by 6 h and fully by 24 h.
The up to 7‐fold increase in threshold after complete recovery of conduction was associated with excitability changes that could only partially be explained by block of the voltage‐gated Na+ channel (VGSC).
Mathematical modelling indicated that, apart from a reduction in the number of functioning VGSCs, lidocaine also caused a decrease of passive membrane resistance and an increase of capacitance.
Our data suggest that lidocaine, even at clinical ‘sub‐blocking’ concentrations, could cause a reversible structural impairment of the axolemma.
AbstractThe local anaesthetic lidocaine is known to block voltage‐gated Na+ channels (VGSCs), although at high concentration it was also reported to block other ion channel currents as well as to alter lipid membranes. The aim of this study was to investigate whether the clinical regional anaesthetic action of lidocaine could be accounted for solely by the block of VGSCs or whether other mechanisms are also relevant. We tested the recovery of motor axon conduction and multiple measures of excitability by ‘threshold‐tracking’ after ultrasound‐guided distal median nerve regional anaesthesia in 13 healthy volunteers. Lidocaine caused rapid complete motor axon conduction block localized at the wrist. Within 3 h, the force of the abductor pollicis brevis muscle and median motor nerve conduction studies returned to normal. In contrast, the excitability of the motor axons at the wrist remained markedly impaired as indicated by a 7‐fold shift of the stimulus–response curves to higher currents with partial recovery by 6 h and full recovery by 24 h. The strength–duration properties were abnormal with markedly increased rheobase and reduced strength–duration time constant. The changes in threshold during electrotonus, especially during depolarization, were markedly reduced. The recovery cycle showed increased refractoriness and reduced superexcitability. The excitability changes were only partly similar to those previously observed after poisoning with the VGSC blocker tetrodotoxin. Assuming an unaltered ion‐channel gating, modelling indicated that, apart from up to a 4‐fold reduction in the number of functioning VGSCs, lidocaine also caused a decrease of passive membrane resistance and an increase of capacitance. Our data suggest that the lidocaine effects, even at clinical ‘sub‐blocking’ concentrations, could reflect, at least in part, a reversible structural impairment of the axolemma.
Glutamate receptor pores
Authors: Huettner James E. 
Published: April 2014

AbstractGlutamate receptors are ligand‐gated ion channels that mediate fast excitatory synaptic transmission throughout the central nervous system. Functional receptors are homo‐ or heteromeric tetramers with each subunit contributing a re‐entrant pore loop that dips into the membrane from the cytoplasmic side. The pore loops form a narrow constriction near their apex with a wide vestibule toward the cytoplasm and an aqueous central cavity facing the extracellular solution. This article focuses on the pore region, reviewing how structural differences among glutamate receptor subtypes determine their distinct functional properties.
Relative Validity of 3 Accelerometer Models for Estimating Energy Expenditure During Light Activity
Authors: Wetten Alexander Allan , Batterham Marijka , Tan Sze Yen , Tapsell Linda 
Published: April 2014

Background:With physical inactivity inextricably linked to the increasing prevalence of obesity, there is a need for validated methods that measure free-living energy expenditure (EE) within sedentary environments. While accelerometers enable these measurements, few studies have compared device accuracy in such settings. The aim of this study was to investigate the relative validity of the Actigraph, RT3 and SenseWear Armband (SWA).Methods:Twenty-three (11 male, 12 female) participants (age: 25.3 ± 6.3 yr; BMI: 22.6 ± 2.7) wore 3 accelerometers at designated sites during a 4-hour stay in the Whole Room Calorimeter (WRC). Participants performed 2 10-minute bouts of light-intensity exercise (stepping and stationary cycling) and engaged in unstructured sedentary activities. EE estimated by accelerometers was compared with WRC EE derived from measurements of gaseous exchange.Results:The Actigraph and SWA both accurately estimated EE during the stepping exercise. EE estimated by the RT3 during stepping was significantly lower than the WRC value (31.2% ± 15.6%, P < .001). All accelerometers underestimated cycling and unstructured activity EE over the trial period (P < .001).Conclusions:The Actigraph and SWA are both valid tools for quantifying EE during light-intensity stepping. These results provide further valuable information on how accelerometer devices may be appropriately used.
Establishing Wrist-Based Cutpoints for the Actical Accelerometer in Elementary School-Aged Children
Authors: Schaefer Christine Adele , Nace Heidi , Browning Ray 
Published: April 2014

Background:The wrist has become a standard location for accelerometry (ACC) data collection, primarily to optimize compliance, yet interpretation of wrist ACC data is limited due to a lack of calibration studies. This study aimed to establish cutpoints for a wrist-mounted Actical accelerometer in 6- to 11-year-old children using 2 methods.Methods:Metabolic and ACC data (15-sec epoch) were collected during 8 activities in 22 children ages 6–11. Linear regression (LR) and Receiver Operator Characteristics (ROC) were used to examine the relationship between METs and ACC counts. Cutpoints were established at < 1.5, 1.5–2.99, 3–5.99, and ≥ 6 METs for sedentary, light, moderate, and vigorous activity, respectively. Cutpoints were applied to a large, multiday sample of children (n = 269) to examine differences in cutpoints on minutes of moderate to vigorous PA (MVPA).Results:LR and ROC yielded moderate cutpoints of 574 and 388, respectively. When applied to the large sample, LR and ROC cutpoints resulted in an estimated 83 and 140 minutes of daily MVPA, respectively.Conclusions:This study established wrist-mounted Actical cutpoints for children using 2 methods. The differences in cutpoints and their effect on estimates of MVPA in an independent sample highlight challenges associated with establishing cutpoints, suggesting that standardized calibration procedures be developed.
Physical, Policy, and Sociocultural Characteristics of the Primary School Environment are Positively Associated With Children’s Physical Activity During Class Time
Authors: Martin Karen , Bremner Alexandra , Salmon Jo , Rosenberg Michael , Giles-Corti Billie 
Published: April 2014

Background:The objective of this study was to develop a multidomain model to identify key characteristics of the primary school environment associated with children’s physical activity (PA) during class-time.Methods:Accelerometers were used to calculate time spent in moderate-to-vigorous physical activity during class-time (CMVPA) of 408 sixth-grade children (mean ± SD age 11.1 ± 0.43 years) attending 27 metropolitan primary schools in Perth Western Australia. Child and staff self-report instruments and a school physical environment scan administered by the research team were used to collect data about children and the class and school environments. Hierarchical modeling identified key variables associated with CMVPA.Results:The final multilevel model explained 49% of CMVPA. A physically active physical education (PE) coordinator, fitness sessions incorporated into PE sessions and either a trained PE specialist, classroom teacher or nobody coordinating PE in the school, rather than the deputy principal, were associated with higher CMVPA. The amount of grassed area per student and sporting apparatus on grass were also associated with higher CMVPA.Conclusion:These results highlight the relevance of the school’s sociocultural, policy and physical environments in supporting class-based PA. Interventions testing optimization of the school physical, sociocultural and policy environments to support physical activity are warranted.
Is There a Sex Difference in Accelerometer Counts During Walking in Older Adults?
Authors: Van Domelen Dane R. , Caserotti Paolo , Brychta Robert J. , Harris Tamara B. , Patel Kushang V. , Chen Kong Y. , Arnardóttir Nanna Ýr , Eirikdottir Gudny , Launer Lenore J. , Gudnason Vilmundur , Sveinsson Thórarinn , Jóhannsson Erlingur , Koster Annemarie 
Published: April 2014

Background:Accelerometers have emerged as a useful tool for measuring free-living physical activity in epidemiological studies. Validity of activity estimates depends on the assumption that measurements are equivalent for males and females while performing activities of the same intensity. The primary purpose of this study was to compare accelerometer count values in males and females undergoing a standardized 6-minute walk test.Methods:The study population was older adults (78.6 ± 4.1 years) from the AGES-Reykjavik Study (N = 319). Participants performed a 6-minute walk test at a self-selected fast pace while wearing an ActiGraph GT3X at the hip. Vertical axis counts·s−1 was the primary outcome. Covariates included walking speed, height, weight, BMI, waist circumference, femur length, and step length.Results:On average, males walked 7.2% faster than females (1.31 vs. 1.22 m·s−1, P < .001) and had 32.3% greater vertical axis counts·s−1 (54.6 vs. 39.4 counts·s−1, P < .001). Accounting for walking speed reduced the sex difference to 19.2% and accounting for step length further reduced the difference to 13.4% (P < .001).Conclusion:Vertical axis counts·s−1 were disproportionally greater in males even after adjustment for walking speed. This difference could confound free-living activity estimates.
Does Activity-Related Social Support Differ by Characteristics of the Adolescent?
Authors: Edwardson Charlotte Louise , Gorely Trish , Musson Hayley , Duncombe Rebecca , Sandford Rachel 
Published: April 2014

Background:Previous research has shown a positive relationship between activity-related social support provided by parents and peers and adolescents’ physical activity. However, more information is needed on whether activity-related social support differs by sociodemographic characteristics. The purpose of this study was to investigate differences in activity-related social support in a sample of adolescents, by characteristics such as age, gender, socioeconomic status (SES), ethnicity, and physical activity level and to determine which characteristics are the most important predictors of activity-related social support.Methods:Information was provided by 578 boys and 588 girls (11–14 years) on demographic factors, physical activity, and activity-related support. ANOVA, correlations, and multiple regression were performed to address the purposes of the study.Results:Boys, White British, younger, more physically active, and high-SES adolescents perceived more support for physical activity. Age predicted all types of support excluding peer support; ethnicity predicted mother logistic support and sibling support; gender predicted peer support, father explicit modeling, and father logistic support; and SES predicted mother and father logistic support.Conclusions:Families and peers of adolescents who are female, from Black and minority ethnic groups, older, of low-SES, and less active should be targeted for intervention.
How Many Steps Are Enough? Dose–Response Curves for Pedometer Steps and Multiple Health Markers in a Community-Based Sample of Older Australians
Authors: Ewald Ben , Attia John , McElduff Patrick 
Published: April 2014

Background:Although an overall public health target of 10,000 steps per day has been advocated, the dose–response relationship for each health benefit of physical activity may differ.Methods:A representative community sample of 2458 Australian residents aged 55–85 wore a pedometer for a week in 2005–2007 and completed a health assessment. Age-standardized steps per day were compared with multiple markers of health using locally weighted regression to produce smoothed dose–response curves and then to select the steps per day matching 60% or 80% of the range in each health marker.Results:There is a linear relationship between activity level and markers of inflammation throughout the range of steps per day; this is also true for BMI in women and high density lipoprotein in men. For other markers, including waist:hip ratio, fasting glucose, depression, and SF-36 scores, the benefit of physical activity is mostly in the lower half of the distribution.Conclusions:Older adults have no plateau in the curve for some health outcomes, even beyond 12,000 steps per day. For other markers, however, there is a threshold effect, indicating that most of the benefit is achieved by 8000 steps per day, supporting this as a suitable public health target for older adults.
The Effectiveness of Self-Guided Web-Based Physical Activity Interventions Among Patients With a Chronic Disease: A Systematic Review
Authors: Bossen Daniël , Veenhof Cindy , Dekker Joost , de Bakker Dinny 
Published: April 2014

Background:Despite well-documented health benefits, adults with a physical chronic condition do not meet the recommended physical activity (PA) guidelines. Therefore, secondary prevention programs focusing on PA are needed. Web-based interventions have shown promise in the promotion of PA behavior change. We conducted a systematic review to summarize the evidence about the effectiveness of web-based PA interventions in adults with chronic disease.Methods:Articles were included if they evaluated a web-based PA intervention and used a randomized design. Moreover, studies were eligible for inclusion if they used a non- or minimal-treatment control group and if PA outcomes measures were applied. Seven articles were included.Results:Three high-quality studies were statistically significant to the control group, whereas 2 high- and 2 low-quality studies reported nonsignificant findings.Conclusion:Our best evidence synthesis revealed that there is conflicting evidence on the effectiveness of web-based PA interventions in patients with a chronic disease.
Awareness and Knowledge of the Youth 2008 Physical Activity Guidelines for Americans
Authors: DeBastiani Summer Dawn , Carroll Dianna D. , Cunningham Melissa , Lee Sarah , Fulton Janet 
Published: April 2014

Background:To measure parental awareness of government physical activity guidelines and knowledge of the amount of physical activity recommended for youth (ie, 60 minutes per day, 7 days per week) as specified in the 2008 Physical Activity Guidelines for Americans.Methods:A cross-sectional national sample of adults responded to physical activity guideline questions added to the HealthStyles survey in 2009 (n = 1552). The prevalence of parents aware of government physical activity guidelines and knowledgeable of the youth physical activity guideline, specifically, was estimated overall and by parental demographic characteristics (sex, education, income level, race/ethnicity, age group, marital status) and body mass index.Results:In 2009, 34.8% of parents reported being aware of physical activity guidelines, and 9.7% were knowledgeable of the amount of physical activity recommended for youth.Conclusions:Many parents lack awareness and knowledge of the youth physical activity guidelines. The low prevalence estimates suggest the 2008 Physical Activity Guidelines for Americans has not been effectively disseminated. These results may also indicate a need for effective communication strategies to educate and inform parents, an important influencer of children’s health behaviors.
Local Adaptation of the National Physical Activity Plan: Creation of the Active Living Plan for a Healthier San Antonio
Authors: Esparza Laura A. , Velasquez Katherine S. , Zaharoff Annette M. 
Published: April 2014

Background:Physical inactivity and related health consequences are serious public health threats. Effective strategies to facilitate and support active-living opportunities must be implemented at national, state, and local levels. San Antonio, Texas, health department officials launched the Active Living Council of San Antonio (ALCSA) to engage the community in developing a 3- to 5-year plan to promote active living.Methods:A steering committee set preliminary ALCSA aims and established a multisector membership structure modeled after the US National Physical Activity Plan (NPAP). ALCSA adopted governance standards, increased knowledge of physical activity and health, and engaged in an 18-month collaborative master plan writing process.Results:ALCSA selected overarching strategies and evidence-based strategies for each societal sector and adapted strategies to the local context, including tactics, measures of success, and timelines. Community and expert engagement led to a localized plan reflecting national recommendations, the Active Living Plan for a Healthier San Antonio.Conclusion:Multisector collaborations among governmental agencies and community organizations, which were successfully developed in this case to produce the first-ever local adaptation of the NPAP, require clearly defined expectations. Lessons learned in ALCSA’s organizational and plan development can serve as a model for future community-driven efforts to increase active living.