bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing Laxity Characteristics of Hyperextension Knee in Healthy Young Females Using a Knee Ligament Arthrometer
Authors: Lin Hsiu-Chen , Lai Weng-Hang , Chang Chia-Ming , Hsu Horng-Chaung
Published: March 2014

Female athletes are more likely to sustain an anterior cruciate ligament (ACL) injury than male athletes. Previous study has showed that female individuals had larger anterior knee laxity than their male counterparts [1]. Researchers have also reported that knee laxity and hyperextension knee were a possible factor contributing to ACL injury [2]. Loudon showed that a person with hyperextension knee, either healthy or ACL-injured, had poorer proprioceptive control. Even more, ACL-injured subjects with hyperextension knee demonstrated a declined function of proprioception feedback loop and the ability to initiate protective reflexes [3].
Cellular Deformations in Microintegrated Electrospun Poly (Ester Urethane) Urea Scaffolds Under Biaxial Stretch
Authors: Liao Jun , Merryman W. David , Hong Yi , Stella John , Watkins Simon , Wagner William R. , Sacks Michael S.
Published: March 2014

Recently, vascular smooth muscle cells (SMCs) have been electrosprayed concurrently with electrospun biodegradable elastomeric poly (ester urethane) urea (PEUU) to form cell-microintegrated scaffolds [1]. These scaffolds exhibit soft tissue-like elastomeric mechanical properties [2], and are thus promising candidates for repair or replacement of diseased cardiovascular tissues. The level of cellular deformation during in vitro mechanical training will likely influence the extracellular matrix formation. However, these deformations are likely complex and dependent upon both scaffold properties and the cellular interactions with the local fibers. Our objective is to quantify microintegrated cellular deformations in response to biaxial scaffold stretches, using the nuclear aspect ratio (NAR) as an index of overall cellular deformation.
Effect of Corpectomy and Discectomy Fusion Procedures on the Stability of Multi-Level Cervical Construct With Anterior Rigid Screw-Plate Fixation: A Finite Element Model Study
Authors: Hussain Mozammil , Nassr Ahmad N. , Natarajan Raghu N. , Andersson Gunnar B. J. , An Howard S.
Published: March 2014

Cervical fusion is a traditional surgical technique in the management of spondylotic pathologies. An increased rate of arthrodesis has been well stated in the literature by using anterior and/or posterior instrumentation. Despite excellent results for the multi-level cervical fusions, failures due to the pseudarthrosis, graft dislodgement, migration and screw loosening were reported. These failures were also found to be directly proportional to the number of fused levels. The multi-level fusions with a single strut graft (corpectomy) have only two graft-endplate interfaces and a lower rate of pseudarthrosis failures. But it has a longer lever arm and moment, thus disrupting the normal sagittal alignment of the cervical spine. On the other hand, the multi-level fusion with multiple inter-body grafts (discectomy) maintains the sagittal alignment, but a higher rate of pseudarthrosis failures were expected due to a large number of graft-endplate interfaces. Some investigators have advocated a combination of corpectomy and discectomy, while others believe to perform either one of them due to the individual advantages and disadvantages as per their patient needs. Consequently, a dilemma and controversy still exists in the selection of the type of reconstructive fusion technique. The objective of the present study was to compare the biomechanical stability of the three reconstructive fusion techniques — corpectomy, discectomy and combined corpectomy-discectomy. The stability of the superior motion segment was compared to the inferior motion segment to determine the direction of propagation of the adjacent segment disease.
On the Cytoskeleton and Soft Glassy Rheology
Authors: Kiran Kranthi , Govindjee Sanjay , Mofrad Mohammad R. K.
Published: March 2014

Cytoskeleton is an integrated system of biomolecules, providing the cell with shape, integrity, and internal spatial organization. Cytoskeleton is a three-dimensional (3-D) network consisting of a complex mixture of actin filaments, intermediate filaments and microtubules that are collectively responsible for the main structural properties and motilities of the cell. A wide range of theoretical models have been proposed for cytoskeletal mechanics, ranging from continuum models for cell deformation to actin filament-based models for cell motility [1]. Numerous experimental techniques have also been developed to quantify cytoskeletal mechanics, typically involving a mechanical perturbation to the cell in the form of either an imposed deformation or force and observation of the static and dynamic response of the cell. These experimental measurements along with new theoretical approaches have given rise to several theories for describing the mechanics of living cells, modeling the cytoskeleton as a simple mechanical elastic, viscoelastic, or poro-viscoelastic continuum, tensegrity (tension integrity) network incorporating discrete structural elements that bear compression, porous gel or most recently soft glassy material. In this paper, we will revisit cytoskeleton as a soft glassy material and give insights in to new dynamic relationships for cytoskeleton.
Soft Filaments Circulate Longer Than Spherical Particles - Shape Effects in Flow and Drug Delivery
Authors: Discher Dennis E. , Dalhaimer Paul
Published: March 2014

Interaction of spherical particles with cells and within animals has been studied extensively, but the effects of shape have received little attention. Here we use highly stable, polymer micelle assemblies known as ‘filomicelles’ to compare the transport and trafficking of these flexible filaments to spheres of similar chemistry. In rodents, filomicelles persisted in the circulation up to 1 week after intravenous injection. This is about ten-fold longer than their spherical counterparts and more persistent than any known synthetic nanoparticle. With cells and in fluid flow conditions, spheres and short filomicelles are taken up by cells more readily than longer filaments because the latter are extended by the flow. Preliminary results further demonstrate that filomicelles can effectively deliver the anticancer drug paclitaxel and shrink human-derived tumors in mice. These findings redefine what is ‘nano’ for circulating vehicles and perhaps also lend insight into shape advantages of natural filoviruses.
Alternative Splicing for Mechanical Resilience: The Softening Effect of Filamin’s Hinge
Authors: Discher Dennis E. , Johnson Colin
Published: March 2014

Alternative splicing within proteins is common but not well understood in its influence on protein structure and stability. Filamins are ubiquitous actin-crosslinking proteins with two dozen Immunolgobulin (Ig) repeats and one alternatively-spliced ‘hinge’ that has been hypothesized to add flexibility. The hinge is also predicted to perturb folding. The molecular mechanics of filamins are probed here by AFM-forced extension, with a particular focus on the ∼30 aa hinge between repeats R15 and R16. After re-examining full-length filamin to clarify the single molecule limit for AFM experiments on long chains, short concatemers of (R15-R16)m and (R15-hinge-R16)m were studied by both AFM and solution structural methods. AFM shows that the hinged isoform extends and unfolds at smaller forces (60 pN) than the hinge-less form (80 pN), implying that the alternative splicing introduces a random coil that softens both adjacent domains. Circular Dichroism confirms that the hinge is a random coil, and thermal unfolding in solution suggests a weak destabilization by the hinge. Together with the rate-dependence of forced extension in AFM, the results reveal added resilience as the unfolding transition shifts to longer lengths upon insertion of the alternatively spliced hinge.
In Vivo Dynamic Strains of the Mitral Valve Annulus
Authors: Zubiate Brett , Sacks Michael , Gorman Robert C. , Gorman Joseph H.
Published: March 2014

The mitral valve apparatus is a complex structure with multiple components that require seamless, integrated operation for normal valve function. One of these components is the annulus, a fibrous ring of tissue that defines the boundary between the mitral valve leaflets and the surrounding superstructure of the heart. During the cardiac cycle the annulus undergoes large deformations and dramatic shape changes. Moreover, the annulus motion represents a key boundary condition for mitral valve leaflet deformation. Yet, to date our knowledge of the subtle deformations this structure undergoes during the cardiac cycle remains very limited. In the present study, an array of 1 mm diameter piezoelectric sonocrystals was implanted in 5 sheep to quantify annular deformation over the complete cardiac cycle. These crystals act as fiducial markers for the mitral annulus with a temporal resolution of ∼1ms and a special resolution of .01mm in a calibrated three dimensional space. A quintic order generalized 3D spline was developed to reconstruct the annular geometry.
Analysis of the Tibio-Femoral Contact Point in Total Knee Replacement Using a Marker Based Motion Analysis System
Authors: Swanson Andrea J. , Ngai Valentina , Inoue Nozomu , Wimmer Markus A.
Published: March 2014

The tibio-femoral contact point in total knee replacements (TKR) is important for determining wear patterns and failure mechanisms of the polyethylene components. Furthermore, the contact point location is critical for determining muscle and ligament lever arms, leading to a more accurate prediction of the internal contact forces.
Dynamic Modeling of Shoulder Girdle Range of Motion Limits
Authors: Garner Brian A.
Published: March 2014

For some applications of musculoskeletal modeling it may be important to simulate the passive responses of joint range-of-motion limits. For example, Lemay and Crago [1] enforced dynamic limits of flexion and extension in an elbow model. In cases such as the elbow where the joint can be modeled as a simple hinge, the range of motion can be easily specified in terms of a minimum and maximum joint angle, and the motion limits can be enforced using simple visco-elastic restraining torques against any limit violations. For joints such as the shoulder girdle, however, which involve multiple articulating bones and multiple degrees of freedom, dynamic enforcement of joint range-of-motion limits requires a more complex approach.
Contribution of Elastin to the Mechanical Properties of Arterial Tissues
Authors: Lammers Steven , Kao Phil , Qi Jerry , Stenmark Kurt , Shandas Robin
Published: March 2014

Recent studies indicate that vascular stiffening and associated remodeling of the proximal pulmonary arteries, due to pulmonary hypertension, may play a critical role in the progression of the disease and ultimate cardiac failure [1]. While progress has been made in the understanding of active and passive arterial mechanics of whole arteries, comparatively little experimental work has been done on the role of the major extracellular structural proteins, collagen and elastin, in determining baseline arterial mechanics and modulating behavior during vascular remodeling [2, 3]. Here, we examine the methods to determine the specific role of elastin in arterial mechanics as it relates to pulmonary hypertension.
Mechanical Properties of the Chick Embryo Spinal Cord
Authors: Elias Ragi A. I. , Maikos Jason , Shreiber David I.
Published: March 2014

Determining the mechanical properties of the spinal cord are useful to identify its response to sub-injurious loading experienced during normal motion, to evaluate the biomechanics of spinal cord injury (SCI) [1], and to understand the role of the changing mechanical environment in growth and development. While an array of studies have focused on the mechanical properties of adult spinal cords, those properties may not be the same as pediatric spinal cords, which undergoes significant changes during development. Additionally, during embryonic and fetal development, axon growth and neural precursor differentiation into neurons are at their peak.
Effects of Interface Conditions and Volume Fraction on the Apparent Stiffness of Surrogate Multicellular Constructs
Authors: Birchler Brian A. , Guilkey James E. , Ellis Benjamin J. , Maas Steve , Weiss Jeffrey A.
Published: March 2014

A common theme in tissue engineering and cell and tissue biomechanics is how the mechanical properties of individual tissue components or embedded cellular structures influence the continuum mechanical behavior of a tissue or construct. Meshless methods provide a useful and convenient computational framework for answering these questions [1], allowing predictions of both the effective mechanical properties of constructs and the local stresses and strains at the level of the cell. Our research focuses on understanding the mechanics of angiogenic microvessels embedded in surrogate extracellular matrix (ECM) materials [1–4]. As a first step toward understanding the interface interactions between microvessels and the ECM, the objectives of this study were to use the material point method (MPM) to analyze models of surrogate microvessels embedded in collagen gel and investigate the effects of microvessel volume fraction and interface conditions between the surrogate vessels and the collagen gel.
Risk of Rupture in AAA and Vulnerable Plaques: Patient Based FSI Simulation
Authors: Bluestein Danny , Alemu Yared , Rissland Peter , Britan Mikahil , Avrahami Idit , Einav Shmuel , Ricotta John
Published: March 2014

Two separate fluid structure interaction (FSI) simulations were performed: a patient-specific Abdominal Aortic Aneurysm (AAA) geometry, and an idealized coronary vulnerable plaque (VP) geometry. VP FSI simulations were later performed in patient based geometries reconstructed from intravascular (IVUS) measurements.

(AAA): The patient specific AAA FSI simulation was carried out with both isotropic and anisotropic wall properties. An orthotropic material model was used to describe wall properties, closely approximate experimental results [1]. Results show peak wall stresses are dependent on the geometry of the AAA and the region of highest stress corresponds to expected failure location. The ability to quantify stresses developing within the aneurysm wall based on FSI simulations will facilitate clinicians to reach informed decisions in determining rupture risk of AAA and the need for surgical intervention.

(Vulnerable Plaque): To study the risk of rupture of a vulnerable plaque in an idealized coronary artery geometry, an FSI simulation was performed. This model of vulnerable plaque includes vessel wall with calcification spot embedded in the fibrous cap, and a lipid core. Identifying rupture risk, regions susceptible to failure and the contribution of the various components were studied. This work led to predicting the rupture risk in patient specific geometries. The results show the upstream side of vulnerable plaque fibrous cap has the highest stresses. The presence of the calcified spot is shown to enhance stresses within the fibrous cap, significantly contributing to its risk of rupture.
Damage Accumulation Model, FSI, and Multiscale Simulations for Studying the Thrombogenic Potential of Prosthetic Heart Valves
Authors: Bluestein Danny , Alemu Yared , Rissland Peter , Dumont Kris , Verdonck Pascal
Published: March 2014

3D physiologic geometry of St. Jude Medical (SJM) valve after implantation was simulated with non-Newtonian two-phase blood model. The simulation used the unsteady Reynolds averaged Navier-Stokes (URANS) approach and the Wilcox k-ω turbulent model. Platelet stress accumulation and the resulting platelet damage were calculated from the results.

Thrombogenic potential of two bileaflet MHV geometries was conducted using fluid-structure interaction (FSI) computation. Two commercially available valve geometries, SJM and ATS, which differ mostly in their hinge design, were simulated in a straight geometry with sudden expansion downstream of the valve. The thrombogenic potential of the two valves was based on computed wall shear stresses on the leaflets and cumulative shear stress on multiple particles released during forward and reverse flow phases.

Platelet stress accumulation along pertinent trajectories from the FSI studies indicated that the SJM valve has a higher thrombogenic potential then the ATS valve.

Flow patterns generated by the valve are conducive to platelet activation provide optimal conditions for activated platelets to interact with each other and form aggregates are hypothesized to be the source of thromboemboli formation, increasing the risk for cardioembolic stroke. The new damage model developed was utilized to estimate the effects of repeated passages and platelet senescence on this thrombogenic potential.

Flow and pressure effects on a cell like a platelet can be well represented by a continuum mechanics model down to the order of the μm level. However, the molecular effects of adhesion/aggregation bonds are on the order of nm. Thus we also adopt a discrete particles dynamics (DPD) approach in which the macroscopic model provides information about the flow induced stresses that may activate blood cellular constituents. This multiscale modeling approach concentrates on flow regions in prosthetic devices like MHVs and cardiovascular pathologies that have a high propensity to activate platelets and form aggregates. Preliminary simulations of blood flow in simple geometries using this approach, which widely departs from the traditional continuum approach, is successful in generating viscous blood flow velocity distributions in these geometries.
Stent Induced Smooth Muscle Cell Proliferation: An In Vitro System for Rapid Evaluation
Authors: Berry Joel L. , Yazdani Saami K.
Published: March 2014

The clinical efficacy of vascular stents is evaluated through long and expensive trials. Pre-clinical studies, where stents are tested in animal models, further contribute to the expense of bringing new devices to market. The purpose of pre-clinical studies is to assess stent induced thrombus formation, inflammatory response, neointimal hyperplasia, and late thromobosis. Whether the trial is pre-clinical or clinical, the biologic responses to stents are, in large part, due to the surface and structural characteristics of the stent being tested.
Can Simple Trunk Muscle Models Balance and Stabilize Lumbar Spine During Support of Symmetric and Asymmetric Loads?: An FE Model Study
Authors: Kiapour A. , Shirazi-Adl A. , Parnianpour M.
Published: March 2014

Biomechanical studies of spine have been concerned about an important issue addressing the question of how the trunk muscles stabilize the spine under enormous loads during work or sport related activities.
A Theoretical Model for Saccular Cerebral Aneurysm Growth: Deformation and Stress Analysis
Authors: Kroon Martin , Holzapfel Gerhard
Published: March 2014

Aneurysms are abnormal dilatations of arteries, and these lesions are found almost exclusively in humans. Saccular cerebral aneurysms occur most frequently in the Circle of Willis, which is a circuit of arteries supplying the brain with blood. Aneurysms of this kind appear in a few percent of the human population in the Western world. Only a few percent of these lesions do actually rupture, but once rupture occurs the consequences are severe, often with death as outcome. Once a cerebral aneurysm is detected, clinicians need to decide whether operation is required or not. These decisions are mainly based on the size of the aneurysm, where larger aneurysms are considered to be more critical than smaller ones. This size criterion is, however, not very reliable, and criteria based on mechanical fields (stress or strain) of the aneurysm should be taken into account in the decision. This, however, requires knowledge of the constitutive behavior of the aneurysm wall, together with patient-specific information regarding geometry and boundary conditions. In order to be able to model the constitutive behavior of an aneurysm, the structural features of the aneurysm wall need to be determined. Knowledge of the etiology of the aneurysm may here provide important insights.
Nonlinear Elastic Behavior of Achilles Tendon at the Fascicle Scale
Authors: Komolafe Oluseeni A. , Doehring Todd C.
Published: March 2014

Parallel collagen fibers such as ligaments and tendons are composed of fiber bundles, or fascicles, enclosed in a sheath of reticular membrane. In the Achilles tendon, these fascicles can be long, extending from the gastro-soleus unit to the calcaneal insertion site (Fig. 1). Although the overall functional behavior of the whole tendon is well established[1], there is little information detailing properties of individual fascicles or their interactions. Knowledge of the structural and biomechanical properties at the “mesostructural” scale (i.e. fascicle-scale) is critical to understanding tissue pathologies; in particular the processes involved in injury and healing, and the development of improved computational models and functional tissue engineered constructs.
A Method to Discriminate Pulmonary Contusion Severity Through Analysis of Hounsfield Unit Frequency
Authors: Gayzik F. Scott , Daly Melissa , Stitzel Joel
Published: March 2014

This study presents a novel approach for the quantification and classification of pulmonary contusion (PC). PC is a common thoracic injury, affecting up to 25% of patients sustaining blunt chest trauma. [1] Contusion volume at the time of hospitalization has been shown to be an independent predictor for the development of Acute Respiratory Distress Syndrome (ARDS), with the risk of ARDS increasing sharply with PC in excess of 20% by volume. [1] Despite the frequency of the injury and strong positive correlation between contusion volume and outcome, there are relatively few contusion quantification methods in the current literature. One such study utilized chest x-ray film to score PC according the amount of lung appearing to be damaged. [2] The study concluded that despite the limitations in using chest x-rays, a PC scoring system may be of value in determining the need for ventilator assistance and predicting outcome. A potentially more accurate approach to quantifying the severity of PC is through the use of computed tomography (CT) chest scans. CT is the preferred modality for obtaining volumetric pulmonary contusion data since the complete three-dimensional lung anatomy is captured. In this work a semi-automated approach is used to analyze PC in an isolated model of lung contusion in the rat. [3, 4] The CT-based approach enables the PC to be precisely quantified as the lesion progresses in time. The technique distinguishes the severity of the contusion by analyzing the composition of bands in the Hounsfield Unit (HU) range of lung image masks.
Rapid thermal annealing effect on GaAsBi/GaAs single quantum wells grown by molecular beam epitaxy
Authors: Grant Perry C. , Fan Dongsheng , Mosleh Aboozar , Yu Shui-Qing , Dorogan Vitaliy G. , Hawkridge Michael E. , Mazur Yuriy I. , Benamara Mourad , Salamo Gregory J. , Johnson Shane R.
Published: March 2014

The effect of rapid thermal annealing on the optical and structural properties of GaAsBi/GaAs quantum wells (QWs) is investigated. The photoluminescence (PL) spectra of the samples are measured at 80 K and room temperature before and after rapid thermal annealing, to ascertain any improvement in the optical quality of the material. The impact of annealing temperature on QW interface quality, layer composition, and thicknesses are studied with x-ray diffraction. For a 60 second annealing time, the low temperature peak PL intensity increases to a maximum of 1.8 times the original intensity at an annealing temperature of 500 °C. Validating this optimum annealing temperature, the room temperature PL peak intensity is seen to increase by 2.2 times. The peak position exhibits a minor blueshift of 15 meV throughout the 450–700 °C temperature range, while annealing at 750 °C produces a blue-shift on the order of 100 meV, indicating out-diffusion of bismuth from the QW. Degradation of the QW interfaces with annealing temperatures above 550 °C is observed. The composition and thickness of the QWs remained constant up to 700 °C. Significant out-diffusion of bismuth and QW thinning are observed at an annealing temperature of 750 °C.
Greater Effect of Adiposity Than Physical Activity or Lean Mass on Physical Function in Community-Dwelling Older Adults
Authors: Ward Christie L. , Valentine Rudy J. , Evans Ellen M.
Published: March 2014

Adiposity, lean mass, and physical activity (PA) are known to influence physical function in older adults, although the independent influences are not completely characterized. Older adults (N = 156, M age = 68.9 ± 6.7 yr, 85 men) were assessed for body composition via dual-energy X-ray absorptiometry, PA by accelerometer, and physical function via timed up-and-go (UP&GO), 30-s chair stand, 6-min walk (6-min WALK), and Star-Excursion Balance Test. In the absence of percentage-body-fat by PA interactions (p > .05), main effects existed such that a higher percentage body fat was associated with poorer performance in UP&GO, 30-s chair stand, and 6-min WALK (p < .05). No significant main effects were found for PA and functional performance. Adiposity explains 4.6–11.4% in physical functional variance (p < .05). Preventing increases in adiposity with age may help older adults maintain functional independence.
Differences in Active Commuting Among Younger and Older Adults
Authors: Bopp Melissa , Der Ananian Cheryl , Campbell Matthew E.
Published: March 2014

The demonstrated health benefits of active commuting (AC) and low participation rates among older adults indicate a need to examine the socioecological correlates of AC by age category. An online survey of employed U.S. adults examined AC participation and individual, employment-related, community, and environmental variables. Participants were dichotomized by age (younger: 18–49 yr; n = 638, 64% and older: ≥50 yr; n = 359, 36%). Logistic-regression analyses examined differences in AC correlates by age. Older adults were less likely to be active commuters (13.4%) than younger adults (27.9%; p < .001) For older adults, analyses yielded a Nagelkerke R2 = .76, with perceived behavioral control, behavioral beliefs, household cars, and walking distance as predictors. Analyses for younger adults resulted in a Nagelkerke R2 = .79, with perceived behavioral control, coworker normative beliefs, parking problems at work, greater employer and community support for AC, and bad weather as predictors. Findings suggest age should be considered when examining and targeting AC behaviors.
The Long-Term Effectiveness of Need-Supportive Physical Activity Counseling Compared With a Standard Referral in Sedentary Older Adults
Authors: Van Hoecke Ann-Sophie , Delecluse Christophe , Bogaerts An , Boen Filip
Published: March 2014

This study compared the long-term effectiveness of three physical activity counseling strategies among sedentary older adults: a 1-contact referral (REFER), a 1-contact individualized walking program (WALK), and multiple-contact, individually tailored, and need-supportive coaching based on the self-determination theory (COACH). Participants (n = 442) completed measurements before (pretest), immediately after (posttest), and 1 yr after (follow-up test) a 10-wk intervention. Linear mixed models demonstrated significant time-by-condition interaction effects from pre- to posttest. More specifically, WALK and COACH yielded larger increases in daily steps and self-reported physical activity than REFER. Similarly, self-reported physical activity increased more from pre- to follow-up test in WALK and COACH compared with REFER. Autonomous motivation mediated the effect of perceived need-support on physical activity, irrespective of counseling strategy. These results demonstrate the long-term effectiveness of both a 1-contact individualized walking program and a more time-consuming, need-supportive coaching, especially in comparison with a standard referral to local opportunities.
Physical and Psychosocial Function in Residential Aged-Care Elders: Effect of Nintendo Wii Sports Games
Authors: Keogh Justin W.L. , Power Nicola , Wooller Leslie , Lucas Patricia , Whatman Chris
Published: March 2014

This mixed-methods, quasi-experimental pilot study examined whether the Nintendo Wii Sports (NWS) active video game (exergame) system could significantly improve the functional ability, physical activity levels, and quality of life of 34 older adults (4 men and 30 women, 83 ± 8 yr) living in 2 residential aged-care (RAC) centers. Change score analyses indicated the intervention group had significantly greater increases in bicep curl muscular endurance, physical activity levels, and psychological quality of life than the control group (p < .05). Analysis of the quotes underlying the 3 themes (feeling silly, feeling good; having fun; and something to look forward to) suggested that intervention group participants developed a sense of empowerment and achievement after some initial reluctance and anxiousness. They felt that the games were fun and provided an avenue for greater socialization. These results add some further support to the utilization of NWS exergames in the RAC context.
The Validity of the Nordic Hamstring Lower for a Field-Based Assessment of Eccentric Hamstring Strength
Authors: Sconce Emma , Jones Paul , Turner Ellena , Comfort Paul , Graham-Smith Philip
Published: March 2014

Context:

Hamstring injury-risk assessment has primarily been investigated using isokinetic dynamometry. However, practical issues such as cost and availability limit the widespread application of isokinetics for injury-risk assessment; thus, field-based alternatives for assessing eccentric hamstring strength are needed.

Objective:

The aim of this study was to investigate the validity of the angle achieved during Nordic hamstring lowers (break-point angle) as a field-based test for eccentric hamstring strength.

Design:

Exploratory study.

Setting:

Laboratory.

Participants:

Sixteen male (n = 7) and female (n = 9) soccer players (mean ± SD age 24 ± 6 y, height 1.77 ± 0.12 m, and body mass 68.5 ± 16.5 kg) acted as subjects for the study.

Main Outcome Measures:

The authors explored relationships between the Nordic break-point angle (the point at which the subject can no longer resist the increasing gravitational moment during a Nordic hamstring lower) measured from video and isokinetic peak torque and angle of peak torque of right- and left-knee flexors.

Results:

The results revealed a meaningful relationship between eccentric knee-flexor peak torque (average of right and left limbs) and the Nordic break-point angle (r = −.808, r2 = 65%, P < .00001). However, there was a weak relationship observed (r = .480, r2 = 23%, P = .06) between break-point angle and the angle of peak torque (average of right and left limbs).

Conclusions:

The results suggest that the break-point angle achieved during Nordic hamstring lowers could be used as a field-based assessment of eccentric hamstring strength.
Gene Therapy for Wiskott-Aldrich Syndrome—Long-Term Efficacy and Genotoxicity
Authors: Braun Christian Jörg , Boztug Kaan , Paruzynski Anna , Witzel Maximilian , Schwarzer Adrian , Rothe Michael , Modlich Ute , Beier Rita , Göhring Gudrun , Steinemann Doris , Fronza Raffaele , Ball Claudia Regina , Haemmerle Reinhard , Naundorf Sonja , Kühlcke Klaus , Rose Martina , Fraser Chris , Mathias Liesl , Ferrari Rudolf , Abboud Miguel R. , Al-Herz Waleed , Kondratenko Irina , Maródi László , Glimm Hanno , Schlegelberger Brigitte , Schambach Axel , Albert Michael Heinrich , Schmidt Manfred , von Kalle Christof , Klein Christoph
Published: March 2014

Wiskott-Aldrich syndrome gene therapy is feasible, but γ-retroviral vectors contribute a substantial risk of leukemogenesis.
Are Two Heads Really Better than One?
Authors: Narla Goutham
Published: March 2014

The PRKCI and SOX2 oncogenes are coamplified and cooperate to activate Hedgehog signaling in lung squamous cell carcinoma.
Selective Association of Outer Surface Lipoproteins with the Lipid Rafts of Borrelia burgdorferi
Authors: Toledo Alvaro , Crowley Jameson T. , Coleman James L. , LaRocca Timothy J. , Chiantia Salvatore , London Erwin , Benach Jorge L.
Published: March 2014

Borrelia burgdorfericontains unique cholesterol-glycolipid-rich lipid rafts that are associated with lipoproteins. These complexes suggest the existence of macromolecular structures that have not been reported for prokaryotes. Outer surface lipoproteins OspA, OspB, and OspC were studied for their participation in the formation of lipid rafts. Single-gene deletion mutants with deletions of ∆ospA, ∆ospB, and ∆ospCand a spontaneous gene mutant, strain B313, which does not express OspA and OspB, were used to establish their structural roles in the lipid rafts. All mutant strains used in this study produced detergent-resistant membranes, a common characteristic of lipid rafts, and had similar lipid and protein slot blot profiles. Lipoproteins OspA and OspB but not OspC were shown to be associated with lipid rafts by transmission electron microscopy. When the ability to form lipid rafts in liveB. burgdorferispirochetes was measured byfluorescenceresonanceenergytransfer (FRET), strain B313 showed a statistically significant lower level of segregation into ordered and disordered membrane domains than did the wild-type and the other single-deletion mutants. The transformation of a B313 strain with a shuttle plasmid containingospArestored the phenotype shared by the wild type and the single-deletion mutants, demonstrating that OspA and OspB have redundant functions. In contrast, a transformed B313 overexpressing OspC neither rescued the FRET nor colocalized with the lipid rafts. Because these lipoproteins are expressed at different stages of the life cycle ofB. burgdorferi, their selective association is likely to have an important role in the structure of prokaryotic lipid rafts and in the organism’s adaptation to changing environments.

IMPORTANCELipid rafts are cholesterol-rich clusters within the membranes of cells. Lipid rafts contain proteins that have functions in sensing the cell environment and transmitting signals. Although selective proteins are present in lipid rafts, little is known about their structural contribution to these domains.Borrelia burgdorferi, the agent of Lyme disease, has lipid rafts, which are novel structures in bacteria. Here, we have shown that the raft-associated lipoproteins OspA and OspB selectively contribute to lipid rafts. A similar but non-raft-associated lipoprotein, OspC, cannot substitute for the role of OspA and OspB. In this study, we have demonstrated that lipoprotein association with lipid rafts is selective, further suggesting a functional adaptation to different stages of the spirochete life cycle. The results of this study are of broader importance and can serve as a model for other bacteria that also possess cholesterol in their membranes and, therefore, may share lipid raft traits withBorrelia.
North American Triple Reassortant and Eurasian H1N1 Swine Influenza Viruses Do Not Readily Reassort to Generate a 2009 Pandemic H1N1-Like Virus
Authors: Ma Wenjun , Liu Qinfang , Qiao Chuanling , del Real Gustavo , García-Sastre Adolfo , Webby Richard J. , Richt Jürgen A.
Published: March 2014

The 2009 pandemic H1N1 virus (pH1N1) was derived through reassortment of North American triple reassortant and Eurasian avian-like swine influenza viruses (SIVs). To date, when, how and where the pH1N1 arose is not understood. To investigate viral reassortment, we coinfected cell cultures and a group of pigs with or without preexisting immunity with a Eurasian H1N1 virus, A/Swine/Spain/53207/2004 (SP04), and a North American triple reassortant H1N1 virus, A/Swine/Kansas/77778/2007 (KS07). The infected pigs were cohoused with one or two groups of contact animals to investigate viral transmission. In coinfected MDCK or PK15 continuous cell lines with KS07 and SP04 viruses, more than 20 different reassortant viruses were found. In pigs without or with preexisting immunity (immunized with commercial inactivated swine influenza vaccines) and coinfected with both viruses, six or seven reassortant viruses, as well as the parental viruses, were identified in bronchoalveolar lavage fluid samples from the lungs. Interestingly, only one or two viruses transmitted to and were detected in contact animals. No reassortant containing a gene constellation similar to that of pH1N1 virus was found in either coinfected cells or pigs, indicating that the reassortment event that resulted in the generation of this virus is a rare event that likely involved specific viral strains and/or a favorable, not-yet-understood environment.

IMPORTANCE
The 2009 pandemic-like H1N1 virus could not be reproduced either in cell cultures or in pigs coinfected with North American triple reassortant H1N1 and Eurasian H1N1 swine influenza viruses. This finding suggests that the generation of the 2009 pandemic H1N1 virus by reassortment was a rare event that likely involved specific viral strains and unknown factors. Different reassortant viruses were detected in coinfected pigs with and without preexisting immunity, indicating that host immunity plays a relevant role in driving viral reassortment of influenza A virus.
Pervasive Transcription of a Herpesvirus Genome Generates Functionally Important RNAs
Authors: Canny Susan P. , Reese Tiffany A. , Johnson L. Steven , Zhang Xin , Kambal Amal , Duan Erning , Liu Catherine Y. , Virgin Herbert W.
Published: March 2014

Pervasive transcription is observed in a wide range of organisms, including humans, mice, and viruses, but the functional significance of the resulting transcripts remains uncertain. Current genetic approaches are often limited by their emphasis on protein-coding open reading frames (ORFs). We previously identified extensive pervasive transcription from the murine gammaherpesvirus 68 (MHV68) genome outside known ORFs and antisense to known genes (termed expressed genomic regions [EGRs]). Similar antisense transcripts have been identified in many other herpesviruses, including Kaposi’s sarcoma-associated herpesvirus and human and murine cytomegalovirus. Despite their prevalence, whether these RNAs have any functional importance in the viral life cycle is unknown, and one interpretation is that these are merely “noise” generated by functionally unimportant transcriptional events. To determine whether pervasive transcription of a herpesvirus genome generates RNA molecules that are functionally important, we used a strand-specific functional approach to target transcripts from thirteen EGRs in MHV68. We found that targeting transcripts from six EGRs reduced viral protein expression, proving that pervasive transcription can generate functionally important RNAs. We characterized transcripts emanating from EGRs 26 and 27 in detail using several methods, including RNA sequencing, and identified several novel polyadenylated transcripts that were enriched in the nuclei of infected cells. These data provide the first evidence of the functional importance of regions of pervasive transcription emanating from MHV68 EGRs. Therefore, studies utilizing mutation of a herpesvirus genome must account for possible effects on RNAs generated by pervasive transcription.

IMPORTANCE
The fact that pervasive transcription produces functionally important RNAs has profound implications for design and interpretation of genetic studies in herpesviruses, since such studies often involve mutating both strands of the genome. This is a common potential problem; for example, a conservative estimate is that there are an additional 73,000 nucleotides transcribed antisense to annotated ORFs from the 119,450-bp MHV68 genome. Recognizing the importance of considering the function of each strand of the viral genome independently, we used strand-specific approaches to identify six regions of the genome encoding transcripts that promoted viral protein expression. For two of these regions, we mapped novel transcripts and determined that targeting transcripts from these regions reduced viral replication and the expression of other viral genes. This is the first description of a function for these RNAs and suggests that novel transcripts emanating from regions of pervasive transcription are critical for the viral life cycle.
Hepatic haemangiomatosis: multinodular liver in an asymptomatic elderly man
Authors: Roque Ramos Lídia , Coelho Margarida Lopes
Published: March 2014

A 66-year-old man, overweight and a heavy drinker, was sent to our clinic to investigate multiple liver nodules detected on ultrasound. The patient had no symptoms, and physical examination was unremarkable. Laboratory evaluation disclosed an isolated two-fold increase of γ-glutamyltransferase. The MRI revealed multiple millimetric hypervascular nodules suggestive of liver haemangiomatosis, though malignancy could not be ruled out. Liver biopsy was consistent with hepatic haemangiomatosis. We discuss the differential diagnosis and therapeutical approach of a patient with hepatic haemangiomatosis involving the entire liver without associated symptoms or liver dysfunction.
Intraoperative hypercarbia and massive surgical emphysema secondary to transanal endoscopic microsurgery (TEMS)
Authors: Chandra Aninda , Clarke Robert , Shawkat Hany
Published: March 2014

We describe a case where full-thickness excision of a rectal lesion caused massive surgical emphysema and subsequent hypercarbia with associated difficulties with ventilation. This unique case highlights the risks of respiratory failure with extraperitoneal insufflation as in this case and as more commonly with intraperitoneal insufflation. Transanal endoscopic microsurgery (TEMS) is a technique that is being increasingly used in the management of large and early malignant rectal polyps. We reviewed the literature in order to understand the case and to highlight factors that should minimise any adverse sequelae. In the presence of ventilatory difficulties secondary to postoperative surgical emphysema, whether via extraperitoneal insufflation as described here or with intraperitoneal insufflation (as in laparoscopy), consider decreasing gas pressures, expediting the procedure, delaying extubation and prolonged close monitoring in recovery with possible admission to a high dependency unit (HDU) or intensive care unit (ICU).
Supratentorial extraventricular anaplastic ependymoma in a child
Authors: Khilji Muhammad Faisal , Hamid Rana Shoaib , Qureshi Asim
Published: March 2014

A young child presented to the emergency department of a tertiary care hospital with on and off headache, focal seizures involving the left side of the body, weakness of left upper and lower limbs and vomiting for 2 weeks. Examination showed an alert child with grade 4/5 powers in left upper and lower limbs. Blood investigations were normal. An urgent CT of the brain showed intra-axial mass in the right frontal cerebral cortex, superolateral to the right lateral ventricle. MRI of the brain showed supratentorial extraventricular mass of 5.20×3.70×3.80 cm, in the right frontal cortex, emitting heterogeneous signals on T1, T2 and fluid-attenuated inversion recovery sequences and impression of astrocytoma, ependymoma or choroid plexus papilloma was made. Complete surgical resection of mass was performed. Histopathology of the mass proved it as WHO grade III anaplastic ependymoma. The child made an uneventful postoperative recovery and radiotherapy was followed.
Coma from wall suction-induced CSF leak complicating spinal surgery
Authors: Fehnel Corey R , Razmara Ali , Feske Steven K
Published: March 2014

A 72-year-old woman was admitted for elective L4/L5 laminectomy. The operative procedure was extradural, and a Jackson-Pratt (JP) drain was placed in the tissue bed and set to wall suction during skin closure. During closure, the patient developed a 15 s period of asystole. The patient was haemodynamically stable, but was comatose for 3 days postoperatively. Cardiac enzymes and EEG were unrevealing. Head CT showed traces of subarachnoid haemorrhage and signs suggestive of cerebral anoxia. JP drain at the incision produced 170–210 mL/day of fluid, positive for β-2 transferrin, indicating cerebrospinal fluid (CSF). The patient fully returned to baseline on hospital day 10. MRI on hospital day 8 normalised. The reversible coma and radiographic findings were most consistent with acute intracranial hypotension relating to acute loss of CSF. Because radiographic findings can mimic hypoxic-ischaemic injury, acute intracranial hypotension should be considered in the differential diagnosis of postoperative coma after cranial or spinal surgery.
Implementation of a quality improvement programme to support advance care planning in five hospitals across a health region
Authors: Schofield G , Kreeger L , Meyer M , Swann D , Wijeratne A , Wood J , Stone P
Published: March 2014

Objectives

Advance care planning (ACP) can help patients with a terminal illness to prepare for the end of their lives. This report describes a regional service improvement initiative to increase the identification of hospital inpatients at this stage in their illnesses and to increase the number of such patients who are offered the opportunity to start the process of ACP.

Methods

Data were collected prospectively over a 7 month period from four acute hospital trusts and a specialist cancer centre in the South-West London region. Each unit identified a specific patient population who were screened for eligibility to engage in the process of ACP. Data concerning the reasons for eligibility, the suitability for discussion and the various reasons why patients did not complete the process, were recorded.

Results

Over a 7 month period 1980 patients were screened and 559 (28.2%) were found to be potentially eligible for an ACP discussion. Of these 227/559 (40.6%) were deemed suitable for a discussion by medical staff. The majority of these patients (195/227; 86%) were offered the opportunity to undergo ACP discussions and 144/195 (73.8%) agreed to begin the process of ACP.

Conclusions

This report shows that a targeted approach can result in increased uptake in the number of patients who engage in ACP. However, systematic identification of potentially eligible patients requires a significant investment of clinical time and resources.
The use of healthcare resources in the last 3 years of life in patients with COPD and lung cancer in Denmark. A retrospective nationwide study
Authors: Husted Marie Gade , Kriegbaum Margit , Kirkegaard Nicolai , Lange Peter
Published: March 2014

Objective

The aim was to describe the use of healthcare resources during the last 3 years of life in patients who died from chronic obstructive pulmonary disease (COPD) or lung cancer (LC), including patients with LC and COPD.

Methods

Using data from Danish health registers, we identified 6648 individuals who, in 2010, died from COPD (n=3013) and LC (n=3635), including 775 from LC and COPD.

Results

Patients with COPD and LC had a high use of services in the last 3 years of life, but the trajectory for COPD was different from that of LC. Fifty-five per cent of subjects with LC received a reimbursement for the terminally ill compared to only 4% of subjects with COPD (p<0.0001). There was a significant increase in the number of individuals with COPD who received non-invasive ventilation (NIV) for the first time in the last 6 months of life. Individuals with COPD and LC had the highest consumption of health resources.

Conclusions

The high use of health resources together with the underuse of economic reimbursement in patients with terminal COPD suggest that more focus should be given to these patients. The need for NIV might be an indicator of poor prognosis and reflect an intensified need for palliative care. The high use of healthcare resources in patients with COPDandLC might indicate a substantial need for palliative care in these patients.