bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of different aerodynamic time trial cycling positions on muscle activation and crank torque
Authors: Fintelman D. M. , Sterling M. , Hemida H. , Li F.‐X.
Published: May 2015

To reduce air resistance, time trial cyclists and triathletes lower their torso angle. The aim of this study was to investigate the effect of lowering time trial torso angle positions on muscle activation patterns and crank torque coordination. It was hypothesized that small torso angles yield a forward shift of the muscle activation timing and crank torque. Twenty‐one trained cyclists performed three exercise bouts at 70% maximal aerobic power in a time trial position at three different torso angles (0°, 8°, and 16°) at a fixed cadence of 85 rpm. Measurements included surface electromyography, crank torques and gas exchange. A significant increase in crank torque range and forward shift in peak torque timing was found at smaller torso angles. This relates closely with the later onset and duration of the muscle activation found in the gluteus maximus muscle. Torso angle effects were only observed in proximal monoarticular muscles. Moreover, all measured physiological variables (oxygen consumption, breathing frequency, minute ventilation) were significantly increased with lowering torso angle and hence decreased the gross efficiency. The findings provide support for the notion that at a cycling intensity of 70% maximal aerobic power, the aerodynamic gains outweigh the physiological/biomechanical disadvantages in trained cyclists.
MRI findings of young male soldiers with atraumatic anterior knee pain
Authors: Kang S. , Park J. , Kang S.‐B. , Chang C. B.
Published: May 2015

The purpose of this study is to investigate abnormal magnetic resonance image (MRI) findings of young active males with atraumatic anterior knee pain (AKP). Targeting young male soldiers, we prospectively gathered and analyzed 157 knee MRIs from patients with atraumatic AKP (AKP group) and 53 knee MRIs from patients without knee pain (control group). Abnormalities of the patellofemoral (PF) joint and extensor mechanism on MRI were more common in the AKP group than the control group (48% vs 13%, P < 0.001). The overall prevalence of medial plica (34% vs 13%, P = 0.004) and the prevalence of the thick medial plica (9% vs 0%, P = 0.023) were considerably higher in the AKP group. The cartilaginous sulcus angle in the AKP group without abnormalities on MRI was significantly higher than both the AKP group with abnormalities and the control group (145° vs 141° vs 142°, respectively, P = 0.001). Our results suggest that careful assessment of young, active males with atraumatic AKP is warranted regarding PF joint abnormalities, particularly the presence of medial plica and/or subtle abnormalities of the articular geometry. The results from the present study could be used for the management of patients with AKP.
Racial Formation Theory and Systemic Racism in Hip‐Hop Fans’ Perceptions
Authors: Jacobson Ginger
Published: May 2015

This work contributes empirical research to racial formation theory (RFT) and systemic racism (SR), demonstrating how these theories complement each other. There are few practical applications of these theories. This research examines RFT and SR from the perspective of hip‐hop fans. I qualitatively examine how 23 nonblack women articulate the relationships of race, class, and gender through discussion of hip‐hop music and videos that accompany it. Findings suggest that hip‐hop is a site of racial formation. Participants spoke from a color‐blind perspective and white racial frame so that they perpetuated ideals of systemic racism theory.
Comparative randomized inverse sampling
Authors: Gasparini Mauro , Von Tress Mark , Heimann Guenter
Published: May 2015

According to previous literature, we define randomized inverse sampling for comparing two treatments with respect to a binary response as the sampling that stops when a total fixed number of successes, irrespective of the treatments, are observed. We have obtained elsewhere the asymptotic distributions for the counting variables involved and have shown them to be equivalent to the corresponding asymptotic distributions for multinomial sampling. In this paper, we start deriving the same basic results using different techniques, and we then show how they give rise to genuinely novel procedures when translated into finite sample approximations. As the main example, a novel confidence interval for the logarithm of the odds ratio of two success probabilities can be constructed in the case of comparative randomized inverse sampling. Some advantages over the standard multinomial sampling in terms of coverage probabilities are visible when no adjustment for cells with zero counts is applied; otherwise, the two sampling schemes appear to be fairly equivalent. This is a reassurance that under certain circumstances, inverse sampling can be safely chosen over more traditional sampling schemes.
Cost‐effectiveness of Babesia microti antibody and nucleic acid blood donation screening using results from prospective investigational studies
Authors: Bish Ebru K. , Moritz Erin D. , El‐Amine Hadi , Bish Douglas R. , Stramer Susan L.
Published: May 2015

BACKGROUND

Babesia microti causes transfusion‐transmitted babesiosis (TTB); currently, blood donor screening assays are unlicensed but used investigationally.

STUDY DESIGN AND METHODS

We developed a decision tree model assessing the comparative‐ and cost‐effectiveness of B. microti blood donation screening strategies in endemic areas compared to the status quo (question regarding a history of babesiosis), including testing by: 1) universal antibody (Ab), 2) universal polymerase chain reaction (PCR), 3) universal Ab/PCR, and 4) recipient risk–targeted Ab/PCR. The model predicted the number of TTB cases, complicated TTB cases, cases averted, and quality‐adjusted life years (QALYs). Economic outcomes included each strategy's per‐donation cost, waste (number of infection‐free units incorrectly discarded), and waste index (number wasted units/number true positives). Sensitivity analyses examined uncertainty in transmission probabilities, prevalence rates, and other key model inputs.

RESULTS

Universal PCR in four endemic states would prevent 24 to 31 TTB cases/100,000 units transfused (pht) at an incremental cost‐effectiveness ratio (ICER) of $26,000 to $44,000/QALY (transmission probability dependent) and waste index of zero. Universal Ab/PCR would prevent 33 to 42 TTB cases pht at an ICER of $54,000 to $83,000/QALY and waste index of 0.05. The questionnaire is most wasteful (99.62 units wasted pht; 208.62 waste index), followed by the risk‐targeted strategy (76.27 units wasted pht; 0.68 waste index). The model predicted zero cases of TTB or complicated TTB with universal Ab/PCR (versus [33, 42] and [13, 18] pht, respectively [no screening]). Results are highly sensitive to transmission probabilities.

CONCLUSIONS

Universal PCR in endemic states is an effective blood donation screening strategy at a threshold of $50,000/QALY. Using a higher cost‐effectiveness ratio, universal Ab/PCR is the most effective strategy.
The ventilatory response to muscle afferent activation during concurrent hypercapnia in humans: central and peripheral mechanisms
Authors: Bruce Richard M. , White Michael J.
Published: May 2015

New Findings

What is the central question of this study?

During hypercapnia but not normocapnia, activation of muscle afferents by postexercise circulatory occlusion increases ventilation, possibly due to additional activation of metabolite‐stimulated muscle afferents. Alternatively, chemoreflex activation caused by hypercapnia may have a synergistic interaction with muscle afferent feedback, so stimulating breathing.

What is the main finding and its importance?

Muscle afferent activation during muscle hypercapnia with concurrent systemic normocapnia did not increase breathing. With systemic hypercapnia, there was a response that did not change with hyperoxic hypercapnia. A synergistic interaction between central chemoreception and muscle afferent feedback is therefore indicated.

During hypercapnia, activation of thin‐fibre muscle afferents using postexercise circulatory occlusion (PECO) provokes a ventilatory response not seen in normocapnia. We investigated the ventilatory responses to PECO when hypercapnia was restricted to the active muscle (‘Local’ trial) or during systemic hypercapnia (‘Systemic’ trial). In the Local trial, a hypercapnic gas mixture (5% CO2 in air) was inhaled for 5 min when circulation to the active calf muscle was open, then rapidly closed by thigh‐cuff inflation (200 mmHg), immediately before a return to breathing room air and performance of isometric exercise and PECO. In the Systemic trial, circulation through the muscle was closed throughout the exercise and PECO phases, performed during the hypercapnic gas inhalation. In a third trial, in Systemic conditions a hyperoxic hypercapnic gas mixture (95% O2 and 5% CO2) was breathed for 1 min during PECO (‘Hyperoxia’ trial). The increase in ventilation during calf muscle exercise was not different between trials. In the Local trial, ventilation fell to pre‐exercise levels during PECO, but in the Systemic trial it remained at end‐exercise levels (4.9 ± 0.8 l min−1) and was equally well maintained throughout the Hyperoxia trial (4.3 ± 1 l min−1). Cardiovascular responses during PECO were not different in the three trials, indicating similar activation of muscle afferents. Sustained elevation of ventilation during PECO in the Systemic but not the Local trial suggests that ventilation is stimulated via an interaction between muscle afferent feedback and hypercapnia‐induced chemoreceptor activation. The similar ventilatory responses in Systemic and Hyperoxia conditions further suggest that in this respect, central rather than peripheral chemoreceptors play the major role.
Infarcted Left Ventricles Have Stiffer Material Properties and Lower Stiffness Variation: Three-Dimensional Echo-Based Modeling to Quantify In Vivo Ventricle Material Properties
Authors: Fan Longling , Yao Jing , Yang Chun , Tang Dalin , Xu Di
Published: May 2015

Methods to quantify ventricle material properties noninvasively using in vivo data are of great important in clinical applications. An ultrasound echo-based computational modeling approach was proposed to quantify left ventricle (LV) material properties, curvature, and stress/strain conditions and find differences between normal LV and LV with infarct. Echo image data were acquired from five patients with myocardial infarction (I-Group) and five healthy volunteers as control (H-Group). Finite element models were constructed to obtain ventricle stress and strain conditions. Material stiffening and softening were used to model ventricle active contraction and relaxation. Systolic and diastolic material parameter values were obtained by adjusting the models to match echo volume data. Young's modulus (YM) value was obtained for each material stress–strain curve for easy comparison. LV wall thickness, circumferential and longitudinal curvatures (C- and L-curvature), material parameter values, and stress/strain values were recorded for analysis. Using the mean value of H-Group as the base value, at end-diastole, I-Group mean YM value for the fiber direction stress–strain curve was 54% stiffer than that of H-Group (136.24 kPa versus 88.68 kPa). At end-systole, the mean YM values from the two groups were similar (175.84 kPa versus 200.2 kPa). More interestingly, H-Group end-systole mean YM was 126% higher that its end-diastole value, while I-Group end-systole mean YM was only 29% higher that its end-diastole value. This indicated that H-Group had much greater systole–diastole material stiffness variations. At beginning-of-ejection (BE), LV ejection fraction (LVEF) showed positive correlation with C-curvature, stress, and strain, and negative correlation with LV volume, respectively. At beginning-of-filling (BF), LVEF showed positive correlation with C-curvature and strain, but negative correlation with stress and LV volume, respectively. Using averaged values of two groups at BE, I-Group stress, strain, and wall thickness were 32%, 29%, and 18% lower (thinner), respectively, compared to those of H-Group. L-curvature from I-Group was 61% higher than that from H-Group. Difference in C-curvature between the two groups was not statistically significant. Our results indicated that our modeling approach has the potential to determine in vivo ventricle material properties, which in turn could lead to methods to infer presence of infarct from LV contractibility and material stiffness variations. Quantitative differences in LV volume, curvatures, stress, strain, and wall thickness between the two groups were provided.
Applicability of the ASME Exemption Curve for Chinese Pressure Vessel Steel Q345R
Authors: Cui Qingfeng , Hui Hu , Li PeiNing
Published: May 2015

Q345R steel is the most commonly used material in fabrication of the pressure vessels and boilers in China, due to its excellent properties. In 2010, ASME code case 2642 accepted Q345R steel for use in construction of pressure vessels. The code case specified impact test exemption curve A for the impact test requirements for Q345R. However, this provision severely limits the application of this material at low temperature, since most of the minimum design metal temperature (MDMT) of curve A is above the freezing point. In this paper, a series of tests (such as uniaxial tensile test, impact test, and fracture toughness test) were carried out at low temperature to investigate the mechanical properties of Q345R steel plates with thickness of 36–80 mm. This study of low temperature usage of Q345R steel was conducted using the fracture mechanics assessment procedure of API 579-1/ASME FFS-1. The fracture toughness is given by master curve (MC) method in the transition regime. The results show that Q345R can be used at lower temperature and that classifying Q345R steel into curve D is appropriate.
Simulating Pitching Blade With Free Vortex Model Coupled With Dynamic Stall Model for Conditions of Straight Bladed Vertical Axis Turbines
Authors: Dyachuk Eduard , Goude Anders , Berhnoff Hans
Published: May 2015

This study is on the straight bladed vertical axis turbines (VATs), which can be utilized for both wind and marine current energy. VATs have the potential of lower installation and maintenance cost. However, complex unsteady fluid mechanics of these turbines imposes significant challenges to the simulation tools. Dynamic stall is one of the phenomena associated with the unsteady conditions, and it is in the focus of the study. The dynamic stall effects are very important for VATs, since they are usually passively controlled through the dynamic stall. A free vortex model is used to calculated unsteady attached flow, while the separated flow is handled by the dynamic stall model. This is compared to the model based solely on the Leishman–Beddoes algorithm. The results are assessed against the measured data on pitching airfoils. A comparison of force coefficients between the simulations and experiments is done at the conditions similar to the conditions of H-rotor type VATs.
Relationships Between the Coach-Created Motivational Climate and Athlete Engagement in Youth Sport
Authors: Curran Thomas , Hill Andrew P. , Hall Howard K. , Jowett Gareth E.
Published: May 2015

Youth sport is a source of well-being for adolescents, yet experiences vary and attrition can be high. We sought to better understand the coach behaviors that foster positive experiences in youth sport by examining relationships between the motivational climate and athlete engagement (viz., confidence, dedication, enthusiasm, and vigor). We reasoned that a mastery climate (emphasis on effort and learning) would correspond with higher engagement, whereas a performance climate (emphasis on ability and outcome) was expected to correspond with lower engagement. Two-hundred sixty adolescent soccer players completed measures of engagement and perceived coach motivational climate. All dimensions of engagement were positively predicted by a mastery climate. Furthermore, cognitive aspects of engagement were positively predicted by a performance climate. Canonical correlation analysis indicated that a composite of engagement was positively associated with a mastery climate. Results suggest that a mastery climate offers a means of promoting higher levels of overall engagement.
Affective and Enjoyment Responses to High-Intensity Interval Training in Overweight-to-Obese and Insufficiently Active Adults
Authors: Martinez Nic , Kilpatrick Marcus W. , Salomon Kristen , Jung Mary E. , Little Jonathan P.
Published: May 2015

High-intensity interval training (HIIT) has many known physiological benefits, but research investigating the psychological aspects of this training is limited. The purpose of the current study is to investigate the affective and enjoyment responses to continuous and high-intensity interval exercise sessions. Twenty overweight-to-obese, insufficiently active adults completed four counterbalanced trials: a 20-min trial of heavy continuous exercise and three 24-min HIIT trials that used 30-s, 60-s, and 120-s intervals. Affect declined during all trials (p < .05), but affect at the completion of trials was more positive in the shorter interval trials (p < .05). Enjoyment declined in the 120-s interval and heavy continuous conditions only (p < .05). Postexercise enjoyment was higher in the 60-s trial than in the 120-s trial and heavy continuous condition (p < .05). Findings suggest that pleasure and enjoyment are higher during shorter interval trials than during a longer interval or heavy continuous exercise.
A Synthetic Influenza Virus Vaccine Induces a Cellular Immune Response That Correlates with Reduction in Symptomatology and Virus Shedding in a Randomized Phase Ib Live-Virus Challenge in Humans
Authors: Pleguezuelos Olga , Robinson Stuart , Fernández Ana , Stoloff Gregory A. , Mann Alex , Gilbert Anthony , Balaratnam Ganesh , Wilkinson Tom , Lambkin-Williams Rob , Oxford John , Caparrós-Wanderley Wilson
Published: May 2015

Current influenza vaccines elicit primarily antibody-based immunity. They require yearly revaccination and cannot be manufactured until the identification of the circulating viral strain(s). These issues remain to be addressed. Here we report a phase Ib trial of a vaccine candidate (FLU-v) eliciting cellular immunity. Thirty-two males seronegative for the challenge virus by hemagglutination inhibition assay participated in this single-center, randomized, double-blind study. Volunteers received one dose of either the adjuvant alone (placebo,n= 16) or FLU-v (500 μg) and the adjuvant (n= 16), both in saline. Twenty-one days later, FLU-v (n= 15) and placebo (n= 13) volunteers were challenged with influenza virus A/Wisconsin/67/2005 (H3N2) and monitored for 7 days. Safety, tolerability, and cellular responses were assessed pre- and postvaccination. Virus shedding and clinical signs were assessed postchallenge. FLU-v was safe and well tolerated. No difference in the prevaccination FLU-v-specific gamma interferon (IFN-γ) response was seen between groups (average ± the standard error of the mean [SEM] for the placebo and FLU-v, respectively, 1.4-fold ± 0.2-fold and 1.6-fold ± 0.5-fold higher than the negative-control value). Nineteen days postvaccination, the FLU-v group, but not the placebo group, developed FLU-v-specific IFN-γ responses (8.2-fold ± 3.9-fold versus 1.3-fold ± 0.1-fold higher than the negative-control value [average ± SEM] for FLU-v versus the placebo [P= 0.0005]). FLU-v-specific cellular responses also correlated with reductions in both viral titers (P= 0.01) and symptom scores (P= 0.02) postchallenge. Increased cellular immunity specific to FLU-v correlates with reductions in both symptom scores and virus loads. (This study has been registered at ClinicalTrials.gov under registration no. NCT01226758 and at hra.nhs.uk under EudraCT no. 2009-014716-35.)
Interferon Gamma Release Assays for Diagnosis of Pleural Tuberculosis: a Systematic Review and Meta-Analysis
Authors: Aggarwal Ashutosh N. , Agarwal Ritesh , Gupta Dheeraj , Dhooria Sahajal , Behera Digambar
Published: May 2015

The role of interferon gamma release assays (IGRAs), although established for identifying latent tuberculosis, is still evolving in the diagnosis of active extrapulmonary tuberculosis. We systematically evaluated the diagnostic performance of blood- and pleural fluid-based IGRAs in tuberculous pleural effusion (TPE). We searched the PubMed and Embase databases for studies evaluating the use of commercially available IGRAs on blood and/or pleural fluid samples for diagnosing TPE. The quality of the studies included was assessed through the QUADAS-2 tool. The pooled estimates of sensitivity and specificity with 95% confidence intervals (95% CI) were generated using a bivariate random-effects model and examined using forest plots and hierarchical summary receiver operating characteristic (HSROC) curves. Indeterminate IGRA results were included for sensitivity calculations. Heterogeneity was explored through subgroup analysis and meta-regression based on prespecified covariates. We identified 19 studies assessing the T.SPOT.TB and/or QuantiFERON assays. There were 20 and 14 evaluations, respectively, of whole-blood and pleural fluid assays, involving 1,085 and 727 subjects, respectively. There was only one good-quality study, and five studies used nonstandard assay thresholds. The pooled sensitivity and specificity for the blood assays were 0.77 (95% CI, 0.71 to 0.83) and 0.71 (95% CI, 0.65 to 0.76), respectively. The pooled sensitivity and specificity for the pleural fluid assays were 0.72 (95% CI, 0.55 to 0.84) and 0.78 (95% CI, 0.65 to 0.87), respectively. There was considerable heterogeneity; however, multivariate meta-regression did not identify any covariate with significant influence. There was no publication bias for blood assays. We conclude that commercial IGRAs, performed either on whole-blood or pleural fluid samples, have poor diagnostic accuracy in patients suspected to have TPE.
Identification and Clinical Significance of Helcococcus kunzii in Human Samples
Authors: Vergne Anne , Guérin François , Lienhard Reto , Le Coustumier Alain , Daurel Claire , Isnard Christophe , Marty Nicole , Poyart Claire , Cattoir Vincent
Published: May 2015

From 2008 to 2013, 39
Helcococcus kunzii
strains were collected from human clinical specimens (79% from foot ulcers), and 85% of the 39 patients were infected. Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry and molecular methods accurately identified all isolates. This large study of clinical observations confirms the potential pathogenic role of
H. kunzii
.
Cytokine-Mediated Activation of NK Cells during Viral Infection
Authors: Freeman Bailey E. , Raué Hans-Peter , Hill Ann B. , Slifka Mark K.
Published: May 2015

Natural killer (NK) cells provide a first line of defense against infection via the production of antiviral cytokines and direct lysis of target cells. Cytokines such as interleukin 12 (IL-12) and IL-18 are critical regulators of NK cell activation, but much remains to be learned about how cytokines interact to regulate NK cell function. Here, we have examined cytokine-mediated activation of NK cells during infection with two natural mouse pathogens, lymphocytic choriomeningitis virus (LCMV) and murine cytomegalovirus (MCMV). Using a systematic screen of 1,849 cytokine pairs, we identified the most potent combinations capable of eliciting gamma interferon (IFN-γ) production in NK cells. We observed that NK cell responses to cytokine stimulation were reduced 8 days after acute LCMV infection but recovered to preinfection levels by 60 days postinfection. In contrast, during MCMV infection, NK cell responses to cytokines remained robust at all time points examined. Ly49H-positive (Ly49H+) NK cells recognizing viral ligand m157 showed preferential proliferation during early MCMV infection. A population of these cells was still detected beyond 60 days postinfection, but these divided cells did not demonstrate enhanced IFN-γ production in response to innate cytokine stimulation. Instead, the maturation state of the NK cells (as determined by CD11b or CD27 surface phenotype) was predictive of responsiveness to cytokines, regardless of Ly49H expression. These results help define cytokine interactions that regulate NK cell activation and highlight variations in NK cell function during two unrelated viral infections.

IMPORTANCENatural killer cells play an important role in immunity to many viral infections. From an initial screen of 1,849 cytokine pairs, we identified the most stimulatory cytokine combinations capable of inducing IFN-γ production by NK cells. Ly49H+NK cells, which can be directly activated by MCMV protein m157, preferentially proliferated during MCMV infection but did not show enhanced IFN-γ production following directex vivocytokine stimulation. Instead, mature CD11b+and/or CD27+NK cells responded similarly to innate cytokine stimulation regardless of Ly49H expression. Collectively, our data provide a better foundation for understanding cytokine-mediated NK cell activation during viral infection.
Varicella-Zoster Virus and Herpes Simplex Virus 1 Differentially Modulate NKG2D Ligand Expression during Productive Infection
Authors: Campbell Tessa M. , McSharry Brian P. , Steain Megan , Slobedman Barry , Abendroth Allison
Published: May 2015

Natural killer (NK) cell-deficient patients are particularly susceptible to severe infection with herpesviruses, especially varicella-zoster virus (VZV) and herpes simplex virus 1 (HSV-1). The critical role that NK cells play in controlling these infections denotes an intricate struggle for dominance between virus and NK cell antiviral immunity; however, research in this area has remained surprisingly limited. Our study addressed this absence of knowledge and found that infection with VZV was not associated with enhanced NK cell activation, suggesting that the virus uses specific mechanisms to limit NK cell activity. Analysis of viral regulation of ligands for NKG2D, a potent activating receptor ubiquitously expressed on NK cells, revealed that VZV differentially modulates expression of the NKG2D ligands MICA, ULBP2, and ULBP3 by upregulating MICA expression while reducing ULBP2 and ULBP3 expression on the surface of infected cells. Despite being closely related to VZV, infection with HSV-1 produced a remarkably different effect on NKG2D ligand expression. A significant decrease in MICA, ULBP2, and ULBP3 was observed with HSV-1 infection at a total cellular protein level, as well as on the cell surface. We also demonstrate that HSV-1 differentially regulates expression of an additional NKG2D ligand, ULBP1, by reducing cell surface expression while total protein levels are unchanged. Our findings illustrate both a striking point of difference between two closely related alphaherpesviruses, as well as suggest a powerful capacity for VZV and HSV-1 to evade antiviral NK cell activity through novel modulation of NKG2D ligand expression.

IMPORTANCEPatients with deficiencies in NK cell function experience an extreme susceptibility to infection with herpesviruses, in particular, VZV and HSV-1. Despite this striking correlation, research into understanding how these two alphaherpesviruses interact with NK cells is surprisingly limited. Through examination of viral regulation of ligands to the activating NK cell receptor NKG2D, we reveal patterns of modulation by VZV, which were unexpectedly varied in response to regulation by HSV-1 infection. Our study begins to unravel the undoubtedly complex interactions that occur between NK cells and alphaherpesvirus infection by providing novel insights into how VZV and HSV-1 manipulate NKG2D ligand expression to modulate NK cell activity, while also illuminating a distinct variation between two closely related alphaherpesviruses.
Conservation of G-Protein Epitopes in Respiratory Syncytial Virus (Group A) Despite Broad Genetic Diversity: Is Antibody Selection Involved in Virus Evolution?
Authors: Trento Alfonsina , Ábrego Leyda , Rodriguez-Fernandez Rosa , González-Sánchez Maria Isabel , González-Martínez Felipe , Delfraro Adriana , Pascale Juan M. , Arbiza Juan , Melero José A.
Published: May 2015

Worldwide G-glycoprotein phylogeny of human respiratory syncytial virus (hRSV) group A sequences revealed diversification in major clades and genotypes over more than 50 years of recorded history. Multiple genotypes cocirculated during prolonged periods of time, but recent dominance of the GA2 genotype was noticed in several studies, and it is highlighted here with sequences from viruses circulating recently in Spain and Panama. Reactivity of group A viruses with monoclonal antibodies (MAbs) that recognize strain-variable epitopes of the G glycoprotein failed to correlate genotype diversification with antibody reactivity. Additionally, no clear correlation was found between changes in strain-variable epitopes and predicted sites of positive selection, despite both traits being associated with the C-terminal third of the G glycoprotein. Hence, our data do not lend support to the proposed antibody-driven selection of variants as a major determinant of hRSV evolution. Other alternative mechanisms are considered to account for the high degree of hRSV G-protein variability.

IMPORTANCE
An unusual characteristic of the G glycoprotein of human respiratory syncytial virus (hRSV) is the accumulation of nonsynonymous (N) changes at higher rates than synonymous (S) changes, reaching dN/dS values at certain sites predictive of positive selection. Since these sites cluster preferentially in the C-terminal third of the G protein, like certain epitopes recognized by murine antibodies, it was proposed that immune (antibody) selection might be driving the apparent positive selection, analogous to the antigenic drift observed in the influenza virus hemagglutinin (HA). However, careful antigenic and genetic comparison of the G glycoprotein does not provide evidence of antigenic drift in the G molecule, in agreement with recently published data which did not indicate antigenic drift in the G protein with human sera. Alternative explanations to the immune-driven selection hypothesis are offered to account for the high level of G-protein genetic diversity highlighted in this study.
Respiratory Syncytial Virus Inhibitor AZ-27 Differentially Inhibits Different Polymerase Activities at the Promoter
Authors: Noton Sarah L. , Nagendra Kartikeya , Dunn Ewan F. , Mawhorter Michael E. , Yu Qin , Fearns Rachel
Published: May 2015

Respiratory syncytial virus (RSV) is the leading cause of pediatric respiratory disease. RSV has an RNA-dependent RNA polymerase that transcribes and replicates the viral negative-sense RNA genome. The large polymerase subunit (L) has multiple enzymatic activities, having the capability to synthesize RNA and add and methylate a cap on each of the viral mRNAs. Previous studies (H. Xiong et al., Bioorg Med Chem Lett, 23:6789–6793, 2013,
http://dx.doi.org/10.1016/j.bmcl.2013.10.018
; C. L. Tiong-Yip et al., Antimicrob Agents Chemother, 58:3867–3873, 2014,
http://dx.doi.org/10.1128/AAC.02540-14
) had identified a small-molecule inhibitor, AZ-27, that targets the L protein. In this study, we examined the effect of AZ-27 on different aspects of RSV polymerase activity. AZ-27 was found to inhibit equally both mRNA transcription and genome replication in cell-based minigenome assays, indicating that it inhibits a step common to both of these RNA synthesis processes. Analysis in an
in vitro
transcription run-on assay, containing RSV nucleocapsids, showed that AZ-27 inhibits synthesis of transcripts from the 3′ end of the genome to a greater extent than those from the 5′ end, indicating that it inhibits transcription initiation. Consistent with this finding, experiments that assayed polymerase activity on the promoter showed that AZ-27 inhibited transcription and replication initiation. The RSV polymerase also can utilize the promoter sequence to perform a back-priming reaction. Interestingly, addition of AZ-27 had no effect on the addition of up to three nucleotides by back-priming but inhibited further extension of the back-primed RNA. These data provide new information regarding the mechanism of inhibition by AZ-27. They also suggest that the RSV polymerase adopts different conformations to perform its different activities at the promoter.

IMPORTANCE
Currently, there are no effective antiviral drugs to treat RSV infection. The RSV polymerase is an attractive target for drug development, but this large enzymatic complex is poorly characterized, hampering drug development efforts. AZ-27 is a small-molecule inhibitor previously shown to target the RSV large polymerase subunit (C. L. Tiong-Yip et al., Antimicrob Agents Chemother, 58:3867–3873, 2014,
http://dx.doi.org/10.1128/AAC.02540-14
), but its inhibitory mechanism was unknown. Understanding this would be valuable both for characterizing the polymerase and for further development of inhibitors. Here, we show that AZ-27 inhibits an early stage in mRNA transcription, as well as genome replication, by inhibiting initiation of RNA synthesis from the promoter. However, the compound does not inhibit back priming, another RNA synthesis activity of the RSV polymerase. These findings provide insight into the different activities of the RSV polymerase and will aid further development of antiviral agents against RSV.
Herpes Simplex Virus 1 Recruits CD98 Heavy Chain and β1 Integrin to the Nuclear Membrane for Viral De-Envelopment
Authors: Hirohata Yoshitaka , Arii Jun , Liu Zhuoming , Shindo Keiko , Oyama Masaaki , Kozuka-Hata Hiroko , Sagara Hiroshi , Kato Akihisa , Kawaguchi Yasushi
Published: May 2015

Herpesviruses have evolved a unique mechanism for nucleocytoplasmic transport of nascent nucleocapsids: the nucleocapsids bud through the inner nuclear membrane (INM; primary envelopment), and the enveloped nucleocapsids then fuse with the outer nuclear membrane (de-envelopment). Little is known about the molecular mechanism of herpesviral de-envelopment. We show here that the knockdown of both CD98 heavy chain (CD98hc) and its binding partner β1 integrin induced membranous structures containing enveloped herpes simplex virus 1 (HSV-1) virions that are invaginations of the INM into the nucleoplasm and induced aberrant accumulation of enveloped virions in the perinuclear space and in the invagination structures. These effects were similar to those of the previously reported mutation(s) in HSV-1 proteins gB, gH, UL31, and/or Us3, which were shown here to form a complex(es) with CD98hc in HSV-1-infected cells. These results suggested that cellular proteins CD98hc and β1 integrin synergistically or independently regulated HSV-1 de-envelopment, probably by interacting directly and/or indirectly with these HSV-1 proteins.

IMPORTANCECertain cellular and viral macromolecular complexes, such asDrosophilalarge ribonucleoprotein complexes and herpesvirus nucleocapsids, utilize a unique vesicle-mediated nucleocytoplasmic transport: the complexes acquire primary envelopes by budding through the inner nuclear membrane into the space between the inner and outer nuclear membranes (primary envelopment), and the enveloped complexes then fuse with the outer nuclear membrane to release de-enveloped complexes into the cytoplasm (de-envelopment). However, there is a lack of information on the molecular mechanism of de-envelopment fusion. We report here that HSV-1 recruited cellular fusion regulatory proteins CD98hc and β1 integrin to the nuclear membrane for viral de-envelopment fusion. This is the first report of cellular proteins required for efficient de-envelopment of macromolecular complexes during their nuclear egress.
Interferon Beta and Interferon Alpha 2a Differentially Protect Head and Neck Cancer Cells from Vesicular Stomatitis Virus-Induced Oncolysis
Authors: Westcott Marlena M. , Liu Jingfang , Rajani Karishma , D'Agostino Ralph , Lyles Douglas S. , Porosnicu Mercedes
Published: May 2015

Oncolytic viruses (OV) preferentially kill cancer cells due in part to defects in their antiviral responses upon exposure to type I interferons (IFNs). However, IFN responsiveness of some tumor cells confers resistance to OV treatment. The human type I IFNs include one IFN-β and multiple IFN-α subtypes that share the same receptor but are capable of differentially inducing biological responses. The role of individual IFN subtypes in promoting tumor cell resistance to OV is addressed here. Two human IFNs which have been produced for clinical use, IFN-α2a and IFN-β, were compared for activity in protecting human head and neck squamous cell carcinoma (HNSCC) lines from oncolysis by vesicular stomatitis virus (VSV). Susceptibility of HNSCC lines to killing by VSV varied. VSV infection induced increased production of IFN-β in resistant HNSCC cells. When added exogenously, IFN-β was significantly more effective at protecting HNSCC cells from VSV oncolysis than was IFN-α2a. In contrast, normal keratinocytes and endothelial cells were protected equivalently by both IFN subtypes. Differential responsiveness of tumor cells to IFN-α and -β was further supported by the finding that autocrine IFN-β but not IFN-α promoted survival of HNSCC cells during persistent VSV infection. Therefore, IFN-α and -β differentially affect VSV oncolysis, justifying the evaluation and comparison of IFN subtypes for use in combination with VSV therapy. Pairing VSV with IFN-α2a may enhance selectivity of oncolytic VSV therapy for HNSCC by inhibiting VSV replication in normal cells without a corresponding inhibition in cancer cells.

IMPORTANCE
There has been a great deal of progress in the development of oncolytic viruses. However, a major problem is that individual cancers vary in their sensitivity to oncolytic viruses. In many cases this is due to differences in their production and response to interferons (IFNs). The experiments described here compared the responses of head and neck squamous cell carcinoma cell lines to two IFN subtypes, IFN-α2a and IFN-β, in protection from oncolytic vesicular stomatitis virus. We found that IFN-α2a was significantly less protective for cancer cells than was IFN-β, whereas normal cells were equivalently protected by both IFNs. These results suggest that from a therapeutic standpoint, selectivity for cancer versus normal cells may be enhanced by pairing VSV with IFN-α2a.
Pseudorabies Virus Fast Axonal Transport Occurs by a pUS9-Independent Mechanism
Authors: Daniel Gina R. , Sollars Patricia J. , Pickard Gary E. , Smith Gregory A.
Published: May 2015

Reactivation from latency results in transmission of neurotropic herpesviruses from the nervous system to body surfaces, referred to as anterograde axonal trafficking. The virus-encoded protein pUS9 promotes axonal dissemination by sorting virus particles into axons, but whether it is also an effector of fast axonal transport within axons is unknown. To determine the role of pUS9 in anterograde trafficking, we analyzed the axonal transport of pseudorabies virus in the presence and absence of pUS9.
A Transgenic Drosophila melanogaster Model To Study Human T-Lymphotropic Virus Oncoprotein Tax-1-Driven Transformation
In Vivo
Authors: Shirinian Margret , Kambris Zakaria , Hamadeh Lama , Grabbe Caroline , Journo Chloé , Mahieux Renaud , Bazarbachi Ali
Published: May 2015

Human T-cell lymphotropic virus type 1 (HTLV-1)-induced adult T-cell leukemia/lymphoma is an aggressive malignancy. HTLV-2 is genetically related to HTLV-1 but does not cause any malignant disease. HTLV-1 Tax transactivator (Tax-1) contributes to leukemogenesis via NF-κB. We describe transgenic
Drosophila
models expressing Tax in the compound eye and plasmatocytes. We demonstrate that Tax-1 but not Tax-2 induces ommatidial perturbation and increased plasmatocyte proliferation and that the eye phenotype is dependent on Kenny (IKKγ/NEMO), thus validating this new
in vivo
model.
HIV-1 Is Restricted prior to Integration of Viral DNA in Primary Cord-Derived Human CD34
+
Cells
Authors: Griffin Daniel O. , Goff Stephen P.
Published: May 2015

Certain cells have the ability to block retroviral infection at specific stages of the viral cycle by the activities of well-characterized factors and transcriptional silencing machinery. Infection of murine stem cells (MSCs) by the murine leukemia viruses (MLVs) is profoundly blocked postintegration by transcriptional silencing. Here, we show that a dominant point of restriction of HIV-1 in human CD34
+
cells is prior to integration of viral DNA and that HIV-1 restriction by human CD34
+
cells is fundamentally different from MLV restriction by mouse cells.
Evidence-based hamstring injury prevention is not adopted by the majority of Champions League or Norwegian Premier League football teams: the Nordic Hamstring survey
Authors: Bahr Roald , Thorborg Kristian , Ekstrand Jan
Published: May 2015

Background

The Nordic hamstring (NH) exercise programme was introduced in 2001 and has been shown to reduce the risk of acute hamstring injuries in football by at least 50%. Despite this, the rate of hamstring injuries has not decreased over the past decade in male elite football.

Aim

To examine the implementation of the NH exercise programme at the highest level of male football in Europe, the UEFA Champions League (UCL), and to compare this to the Norwegian Premier League, Tippeligaen, where the pioneer research on the NH programme was conducted.

Design

Retrospective survey.

Setting/participants

50 professional football teams, 32 from the UCL and 18 from Tippeligaen.

Methods

A questionnaire, based on the Reach, Efficacy, Adoption, Implementation and Maintenance framework, addressing key issues related to the implementation of the NH programme during three seasons from 2012 through 2014, was distributed to team medical staff using electronic survey software.

Results

The response rate was 100%. Of the 150 club-seasons covered by the study, the NH programme was completed in full in 16 (10.7%) and in part in an additional 9 (6%) seasons. Consequently, 125 (83.3%) club-seasons were classified as non-compliant. There was no difference in compliance between the UCL and Tippeligaen in any season (χ2: 0.41 to 0.52).

Conclusions

Adoption and implementation of the NH exercise programme at the highest levels of male football in Europe is low; too low to expect any overall effect on acute hamstring injury rates.
Multiple sclerosis course and clinical outcomes in patients with comorbid asthma: a survey study
Authors: Manouchehrinia Ali , Edwards Laura J , Roshanisefat Homayoun , Tench Christopher R , Constantinescu Cris S
Published: May 2015

Objective

To determine if comorbid asthma is associated with accumulation of multiple sclerosis (MS)-related impairment and disability.

Method

We sent a comprehensive questionnaire to a cohort of patients with MS and examined the association between comorbid asthma and reaching Expanded Disability Status Scale (EDSS) scores 4.0 and 6.0. Multiple Sclerosis Impact Scale (MSIS-29) scores were compared between patients with MS with and without comorbid asthma.

Results

680 patients participated in our study of whom 88 (12.9%) had comorbid asthma. There was no difference in the prevalence of asthma between our MS cohort and the England general population (OR: 0.89, 95% CI 0.68 to 1.17). We did not observe a significant association between having asthma and the risk of reaching EDSS scores 4.0 and 6.0 (HR: 1.29, 95% CI 0.93 to 1.77, and HR: 1.33, 95% CI 0.93 to 1.89, respectively) after controlling for confounders. Patients with MS with asthma reported higher level of psychological impairments (coefficient: 2.29, 95% CI 0.1 to 4.49).

Conclusions

Asthma is a prevalent condition among patients with MS and it may contribute to the psychological impairment in MS. Although we did not observe significant association between comorbid asthma and physical disability in MS, it seems that the two conditions influence one another.
Risk factors associated with purchasing pesticide from shops for self-poisoning: a protocol for a population-based case–control study
Authors: Weerasinghe Manjula , Konradsen Flemming , Eddleston Michael , Pearson Melissa , Gunnell David , Hawton Keith , Jayamanne Shaluka , Pabasara Chathurani , Jayathilaka Tharidu , Dissanayaka Kalpani , Rajapaksha Sandamali , Thilakarathna Prasanna , Agampodi Suneth
Published: May 2015

Introduction

Pesticide self-poisoning is one of the most frequently used methods of suicide worldwide, killing over 300 000 people annually. Around 15–20% of pesticide self-poisonings occur soon after the person has bought the pesticide from a shop. We aim to determine the characteristics of individuals who purchase pesticides directly from shops and how they differ from individuals who access pesticides from other sources such as home, home garden or farmland. This information will help inform possible vendor/shop-based intervention strategies aimed at reducing access to pesticides used for self-harm.

Methods and analysis

This study will investigate risk factors associated with purchasing pesticides for acts of self-poisoning from pesticide shops, including cases identified over a 9-month period using a population-based case–control group approach. Four interviewer-administered data collection tools will be used for this study: a semistructured questionnaire, Beck Suicidal Intent Scale (SIS), Clinical Interview Schedule—Sinhalese version (CIS-Sn) and Alcohol Use Disorders Identification Test (AUDIT). Each case (expected n=33) will be compared with two groups of individuals: (1) those who have self-poisoned using pesticides from the home, home garden or farmland and (2) those who bought pesticides from the same shops as the above cases, but not did not self-poison. Logistic regression models will be used to identify risk factors of purchasing pesticides for self-poisoning from shops.

Ethics and dissemination

The study has received ethical approval from the Ethical Review Committee of the Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka. A sensitive data collection technique will be used and ethical issues will be considered throughout the study. Results will be disseminated in scientific peer-reviewed articles.