bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flagellar Hook Flexibility Is Essential for Bundle Formation in Swimming Escherichia coli Cells
Authors: Brown Mostyn T. , Steel Bradley C. , Silvestrin Claudio , Wilkinson David A. , Delalez Nicolas J. , Lumb Craig N. , Obara Boguslaw , Armitage Judith P. , Berry Richard M. 
Published: April 2012

ABSTRACT

Swimming
Escherichia coli
cells are propelled by the rotary motion of their flagellar filaments. In the normal swimming pattern, filaments positioned randomly over the cell form a bundle at the posterior pole. It has long been assumed that the hook functions as a universal joint, transmitting rotation on the motor axis through up to ∼90° to the filament in the bundle. Structural models of the hook have revealed how its flexibility is expected to arise from dynamic changes in the distance between monomers in the helical lattice. In particular, each of the 11 protofilaments that comprise the hook is predicted to cycle between short and long forms, corresponding to the inside and outside of the curved hook, once each revolution of the motor when the hook is acting as a universal joint. To test this, we genetically modified the hook so that it could be stiffened by binding streptavidin to biotinylated monomers, impeding their motion relative to each other. We found that impeding the action of the universal joint resulted in atypical swimming behavior as a consequence of disrupted bundle formation, in agreement with the universal joint model.
The Azospirillum brasilense Che1 Chemotaxis Pathway Controls Swimming Velocity, Which Affects Transient Cell-to-Cell Clumping
Authors: Bible Amber , Russell Matthew H. , Alexandre Gladys 
Published: April 2012

ABSTRACT

The Che1 chemotaxis-like pathway of
Azospirillum brasilense
contributes to chemotaxis and aerotaxis, and it has also been found to contribute to regulating changes in cell surface adhesive properties that affect the propensity of cells to clump and to flocculate. The exact contribution of Che1 to the control of chemotaxis and flocculation in
A. brasilense
remains poorly understood. Here, we show that Che1 affects reversible cell-to-cell clumping, a cellular behavior in which motile cells transiently interact by adhering to one another at their nonflagellated poles before swimming apart. Clumping precedes and is required for flocculation, and both processes appear to be independently regulated. The phenotypes of a Δ
aerC
receptor mutant and of mutant strains lacking
cheA1
,
cheY1
,
cheB1
, or
cheR1
(alone or in combination) or with
che1
deleted show that Che1 directly mediates changes in the flagellar swimming velocity and that this behavior directly modulates the transient nature of clumping. Our results also suggest that an additional receptor(s) and signaling pathway(s) are implicated in mediating other Che1-independent changes in clumping identified in the present study. Transient clumping precedes the transition to stable clump formation, which involves the production of specific extracellular polysaccharides (EPS); however, production of these clumping-specific EPS is not directly controlled by Che1 activity. Che1-dependent clumping may antagonize motility and prevent chemotaxis, thereby maintaining cells in a metabolically favorable niche.
Determination of future prevention strategies in elite track and field: analysis of Daegu 2011 IAAF Championships injuries and illnesses surveillance
Authors: Alonso Juan-Manuel , Edouard Pascal , Fischetto Giuseppe , Adams Bob , Depiesse Frédéric , Mountjoy Margo 
Published: April 2012

ObjectiveTo determine the incidence and characteristics of newly incurred injuries and illnesses during international Athletics Championships, by improving the medical surveillance coverage, in order to determine future prevention strategies.DesignProspective recording of newly occurred injuries and illnesses.Setting13th International Association of Athletics Federations World Championships in Athletics 2011 in Daegu, Korea.ParticipantsNational team and Local Organising Committee physicians; and 1851 registered athletes.Main outcome measuresIncidence and characteristics of newly incurred injuries and illnesses.Results82% of athletes were covered by medical teams participating with a response rate of 94%. A total of 249 injuries were reported, representing an incidence of 134.5 injuries per 1000 registered athletes, and 119 (48%) resulted in time loss from sport. A total of 185 injuries affected the lower limb (74%). Hamstring strain was the main diagnosis and 67% resulted in absence from sport. Overuse (n=148; 59%) was the predominant cause. A total of 126 illnesses were reported, signifying an incidence of 68.1 per 1000 registered athletes. Upper respiratory tract infection was the most common reported diagnosis (18%), followed by exercise-induced dehydration (12%), and gastroenteritis/diarrhoea (10%). The highest incidences of injuries were found in combined events and middle and long-distance events, and of illness in race walking events.ConclusionDuring elite Athletics World Championships, 135 injuries, 60 time-loss injuries and 68 illnesses per 1000 registered athletes were reported. Higher risks of injuries were found in combined events and long-distance runs. Preventive interventions should focus on overuse injuries and hamstring strains, decreasing the risk of transmission of infectious diseases, appropriate event scheduling and heat acclimatisation.
Associations between internet-based patient ratings and conventional surveys of patient experience in the English NHS: an observational study
Authors: Greaves Felix , Pape Utz J , King Dominic , Darzi Ara , Majeed Azeem , Wachter Robert M , Millett Christopher 
Published: April 2012

ObjectiveUnsolicited web-based comments by patients regarding their healthcare are increasing, but controversial. The relationship between such online patient reports and conventional measures of patient experience (obtained via survey) is not known. The authors examined hospital level associations between web-based patient ratings on the National Health Service (NHS) Choices website, introduced in England during 2008, and paper-based survey measures of patient experience. The authors also aimed to compare these two methods of measuring patient experience.DesignThe authors performed a cross-sectional observational study of all (n=146) acute general NHS hospital trusts in England using data from 9997 patient web-based ratings posted on the NHS Choices website during 2009/2010. Hospital trust level indicators of patient experience from a paper-based survey (five measures) were compared with web-based patient ratings using Spearman's rank correlation coefficient. The authors compared the strength of associations among clinical outcomes, patient experience survey results and NHS Choices ratings.ResultsWeb-based ratings of patient experience were associated with ratings derived from a national paper-based patient survey (Spearman ρ=0.31–0.49, p<0.001 for all). Associations with clinical outcomes were at least as strong for online ratings as for traditional survey measures of patient experience.ConclusionsUnsolicited web-based patient ratings of their care, though potentially prone to many biases, are correlated with survey measures of patient experience. They may be useful tools for patients when choosing healthcare providers and for clinicians to improve the quality of their services.
Genetic Ablation of SOX18 Function Suppresses Tumor Lymphangiogenesis and Metastasis of Melanoma in Mice
Authors: Duong Tam , Proulx Steven T. , Luciani Paola , Leroux Jean-Christophe , Detmar Michael , Koopman Peter , Francois Mathias 
Published: April 2012

Abstract
The lymphatic vasculature provides a major route for tumor metastasis and inhibiting neolymphangiogenesis induced by tumors can reduce metastasis in animal models. Developmental biology studies have identified the transcription factor SOX18 as a critical switch for lymphangiogenesis in the mouse embryo. Here, we show that SOX18 is also critical for tumor-induced lymphangiogenesis, and we show that suppressing SOX18 function is sufficient to impede tumor metastasis. Immunofluorescence analysis of murine tumor xenografts showed that SOX18 is reexpressed during tumor-induced neolymphangiogenesis. Tumors generated by implantation of firefly luciferase-expressing B16-F10 melanoma cells exhibited a reduced rate of metastasis to the regional draining lymph node in Sox18-deficient mice, as assessed by live bioluminescence imaging. Lower metastatic rates correlated with reduced tumoral lymphatic vessel density and diameter and with impaired drainage of peritumoral injected liposomes specific for lymph vessels from the sentinel lymph nodes. Overall, our findings suggested that SOX18 induction is a key step in mediating tumor lymphangiogenesis and metastasis, and they identify SOX18 as a potential therapeutic target for metastatic blockade. Cancer Res; 72(12); 3105–14. ©2012 AACR.
Osteoprotegerin Is Associated With Aneurysm Diameter and Proteolysis in Abdominal Aortic Aneurysm Disease
Authors: Koole Dave , Hurks Rob , Schoneveld Arjan , Vink Aryan , Golledge Jonathan , Moran Corey S. , de Kleijn Dominique P. , van Herwaarden Joost A. , de Vries Jean-Paul , Laman Jon D. , Huizinga Ruth , Pasterkamp Gerard , Moll Frans L. 
Published: April 2012

Objective—
Serum osteoprotegerin (OPG) concentrations have previously been associated with growth of abdominal aortic aneurysms (AAAs). In vitro experiments showed that OPG promotes matrix metalloprotease (MMP) release from monocytes and vascular smooth muscle cells. We hypothesized that OPG expression is increased in human AAAs and is associated with proteolysis.

Methods and Results—

AAA biopsies were collected from 329 patients. We assessed the concentrations of OPG, cathepsins A, B, and S as well as the activity of MMP-2 and MMP-9. The AAA wall infiltration by macrophages, lymphocytes, and plasma cells was estimated by immunohistochemistry. The concentration of OPG correlated positively with aortic diameter (<55 mm: 16.1 [5.8–28.7], 55–70 mm: 21.9 [10.2–36.0], >70 mm: 24.0 [13.5–52.9] ng OPG/mg total amount of protein,
P
=0.020), cathepsin A (
r
=0.221,
P
=0.005), B (
r
=0.384,
P
<0.001), and S (
r
=0.467, P<0.001), MMP-2 (
r
=0.180,
P
<0.001), MMP-9 (
r
=0.178, P<0.001), and the number of lymphocytes (
P
<0.001) and plasma cells (
P
=0.001). OPG immunostaining was predominantly demonstrated in plasma cells.

Conclusion—
The concentration of aortic wall OPG is positively associated with established markers of AAA severity and pathogenesis. OPG appeared to be associated with lymphocytes and plasma cells. These human data support previous experimental data suggesting a role for OPG in AAA pathogenesis.
Development of a Magnetic Resonance Imaging Protocol for the Characterization of Atherosclerotic Plaque by Using Vascular Cell Adhesion Molecule-1 and Apoptosis-Targeted Ultrasmall Superparamagnetic Iron Oxide Derivatives
Authors: Burtea Carmen , Ballet Sébastien , Laurent Sophie , Rousseaux Olivier , Dencausse Anne , Gonzalez Walter , Port Marc , Corot Claire , Elst Luce Vander , Muller Robert N. 
Published: April 2012

Objective—
Acute ischemic events are often caused by the disruption of lipid-rich plaques, which are frequently not angiographically visible. Vascular cell adhesion molecule-1 and apoptotic cell-targeted peptides studied during our previous work were conjugated to ultrasmall superparamagnetic iron oxide (USPIO) (USPIO-R832 for vascular cell adhesion molecule-1 targeting; USPIO-R826 for apoptosis targeting) and assessed by magnetic resonance imaging.

Methods and Results—
Apolipoprotein E knockout mice were injected with 0.1 mmol Fe/kg body weight and were imaged on a 4.7-T Bruker magnetic resonance imaging until 24 hours after contrast agent administration. Aortic samples were then harvested and examined by histochemistry, and the magnetic resonance images and histological micrographs were analyzed with ImageJ software. The plaques enhanced by USPIO-R832 contained macrophages concentrated in the cap and a large necrotic core, whereas USPIO-R826 produced a negative enhancement of plaques rich in macrophages and neutral fats concentrated inside the plaque. Both USPIO derivatives colocalized with their target on histological sections and were able to detect plaques with a vulnerable morphology, but each one is detecting a specific environment.

Conclusion—
Our vascular cell adhesion molecule-1 and apoptotic cell targeted USPIO derivatives seem to be highly promising tools for atherosclerosis imaging contributing to the detection of vulnerable plaques. They are able to attain their target in low doses and as fast as 30 minutes after administration.
Thrombus Growth and Embolism on Tissue Factor-Bearing Collagen Surfaces Under Flow
Authors: Colace Thomas V. , Muthard Ryan W. , Diamond Scott L. 
Published: April 2012

Objective—
At sites of vascular injury, thrombin is an important mediator in thrombus growth and stability. Using microfluidic flow devices as well as patterned surfaces of collagen and tissue factor (TF), we sought to determine the role that fibrin plays in clot stability without interfering with the production of thrombin.

Methods and Results—

We deployed an 8-channel microfluidic device to study coagulation during corn trypsin inhibitor–treated (XIIa-inhibited) whole blood perfusion over lipidated TF linked to a fibrillar collagen type 1 surface. Clot growth and embolization were measured at initial inlet venous (200 s
−1
) or arterial (1000 s
−1
) wall shear rates under constant flow rate or pressure relief mode in the presence or absence of Gly-Pro-Arg-Pro (GPRP) to block fibrin polymerization. Numerical calculations for each mode defined hemodynamic forces on the growing thrombi. In either mode at inlet venous flow, increasing amounts of TF on the surface led to a modest dose-dependent increase (up to 2-fold) in platelet deposition, but resulted in massive fibrin accumulation (>50-fold) only when exceeding a critical TF threshold. At a venous inlet flow, GPRP led to a slight 20% increase in platelet accumulation (
P
<0.01) in pressure relief mode with thrombi resisting ≈1500 s
−1
before full channel occlusion. GPRP-treated thrombi were unstable under constant flow rate, where shear forces caused embolization at a maximum shear rate of ≈2300 s
−1
(69 dynes/cm2). In constant flow rate mode, the nonocclusive platelet-fibrin deposits (no GPRP) withstood maximum shear rates of ≈29 000 s
−1
(870 dyne/cm2) at ≈95% of full channel occlusion. For arterial inlet shear rate, embolization was marked for either mode with GPRP present when shear forces reached 87 dynes/cm2 (≈2900 s
−1
). Under constant flow rate, platelet-fibrin deposits (no GPRP) withstood maximums of 2400 dynes/cm2 (80,000 s
−1
) at ≈90% of full channel occlusion prior to embolization.

Conclusion—

Fibrin increased clot strength by 12- to 28-fold. Under pressure relief mode, ≈2-fold more fibrin was produced under venous flow (
P
<0.001). These studies define embolization criteria for clots formed with surface TF-triggered thrombin production (±fibrin) under venous and arterial flows.
U.S. Truck Driver Anthropometric Study and Multivariate Anthropometric Models for Cab Designs
Authors: Guan Jinhua , Hsiao Hongwei , Bradtmiller Bruce , Kau Tsui-Ying , Reed Matthew R. , Jahns Steven K. , Loczi Josef , Hardee H. Lenora , Piamonte Dominic Paul T. 
Published: April 2012

Objective: This study presents data from a large-scale anthropometric study of U.S. truck drivers and the multivariate anthropometric models developed for the design of next-generation truck cabs. Background: Up-to-date anthropometric information of the U.S. truck driver population is needed for the design of safe and ergonomically efficient truck cabs. Method: We collected 35 anthropometric dimensions for 1,950 truck drivers (1,779 males and 171 females) across the continental United States using a sampling plan designed to capture the appropriate ethnic, gender, and age distributions of the truck driver population. Results: Truck drivers are heavier than the U.S. general population, with a difference in mean body weight of 13.5 kg for males and 15.4 kg for females. They are also different in physique from the U.S. general population. In addition, the current truck drivers are heavier and different in physique compared to their counterparts of 25 to 30 years ago. Conclusion: The data obtained in this study provide more accurate anthropometric information for cab designs than do the current U.S. general population data or truck driver data collected 25 to 30 years ago. Multivariate anthropometric models, spanning 95% of the current truck driver population on the basis of a set of 12 anthropometric measurements, have been developed to facilitate future cab designs. Application: The up-to-date truck driver anthropometric data and multivariate anthropometric models will benefit the design of future truck cabs which, in turn, will help promote the safety and health of the U.S. truck drivers.
Suppressive effect of chronic peroral topiramate on potassium-induced cortical spreading depression in rats
Authors: Unekawa Miyuki , Tomita Yutaka , Toriumi Haruki , Suzuki Norihiro 
Published: April 2012

Objective: To evaluate the chronic effect of topiramate (TPM) on cortical spreading depression (CSD), which is thought to be related to migraine aura. Methods: Male rats (n = 30) were randomized to once-daily peroral treatment with TPM (50, 100, 200 or 600 mg/kg) or vehicle for 6 weeks. We evaluated the characteristics of CSD induced by topical application of KCl under isoflurane anesthesia and the changes in plasma level of TPM in each group. The effect of single administration of TPM on CSD was also evaluated. Results: After the final administration of TPM, when the plasma level of TPM was high, KCl-induced CSD frequency and CSD propagation velocity were dose-dependently reduced and the interval between CSD episodes was elongated, compared with the vehicle control. However, before the final administration of TPM, when the plasma level was very low, the KCl-induced CSD profile was the same as that in the vehicle control. Single administration of TPM did not alter the CSD profile. Local cerebral blood flow was not significantly altered by chronic administration of TPM. Conclusion: TPM suppressed the frequency and propagation of CSD along the cerebral cortex, and might be a candidate for relief of migraine.
Recruitment and Activity of the Pectineus and Piriformis Muscles During Hip Rehabilitation Exercises
Authors: Giphart J. Erik , Stull Justin D. , LaPrade Robert F. , Wahoff Michael S. , Philippon Marc J. 
Published: April 2012

Background: The pectineus muscle has been reported to function primarily as a hip flexor and secondarily as a hip internal rotator; the piriformis muscle has been reported to function as an abductor and external rotator of the hip. The recruitment and activations of these muscles during hip rehabilitation exercises have not been detailed. Hypothesis: The authors hypothesized that they would measure the highest pectineus activation during exercises involving hip flexion, with moderate pectineus activation during exercises with hip internal rotation. They also hypothesized that they would measure the highest piriformis activation during exercises involving hip abduction and/or external rotation. Study Design: Descriptive laboratory study. Methods: Ten healthy volunteers completed 13 hip rehabilitation exercises with electromyography (EMG) electrodes inserted under ultrasound guidance into the pectineus and piriformis muscle bellies. The EMG signals were recorded and exercise activation levels were reported as a percentage of a maximum voluntary contraction (MVC). Results: Both the highest peak pectineus activation (62.8% ± 26.6% MVC) and the highest mean pectineus activation (33.1% ± 17.4% MVC) were measured during the supine hip flexion exercise. Moderate activation was found during the single- and double-legged bridge and both phases of the stool hip rotation exercise. The highest peak piriformis activation was observed in the single-legged bridge (MVC, 35.7% ± 25.7%), and the highest mean piriformis activation was observed in the prone heel squeeze (MVC, 24.3% ± 8.2%). Similar moderate activation levels were found for single-legged hip abduction and resisted hip extension. Conclusion: The pectineus was highly activated during hip flexion exercises and moderately activated during exercises requiring rotational hip stabilization in either direction, rather than with internal hip rotation only. The piriformis was most activated during static external rotation and abduction while the participants’ hips were in slight extension. These observations indicate that the pectineus and piriformis are both muscles that contribute to hip stabilization. Clinical Relevance: The findings indicate that the pectineus and piriformis function as hip-stabilizing muscles and can be used to specifically address pectineus and piriformis muscle rehabilitation. The authors believe that strengthening and conditioning of these muscles should aid in the restoration of hip function and stability after injury or arthroscopic surgery.
PM10, and children's respiratory symptoms and lung function in the PATY study
Authors: Hoek Gerard , Pattenden Sam , Willers Saskia , Antova Temenuga , Fabianova Eleonora , Braun-Fahrländer Charlotte , Forastiere Francesco , Gehring Ulrike , Luttmann-Gibson Heike , Grize Leticia , Heinrich Joachim , Houthuijs Danny , Janssen Nicole , Katsnelson Boris , Kosheleva Anna , Moshammer Hanns , Neuberger Manfred , Privalova Larisa , Rudnai Peter , Speizer Frank , Slachtova Hana , Tomaskova Hana , Zlotkowska Renata , Fletcher Tony 
Published: April 2012

Studies of the impact of long-term exposure to outdoor air pollution on the prevalence of respiratory symptoms and lung function in children have yielded mixed results, partly related to differences in study design, exposure assessment, confounder selection and data analysis.We assembled respiratory health and exposure data for >45,000 children from comparable cross-sectional studies in 12 countries. 11 respiratory symptoms were selected, for which comparable questions were asked. Spirometry was performed in about half of the children. Exposure to air pollution was mainly characterised by annual average concentrations of particulate matter with a 50% cut-off aerodynamic diameter of 10 μm (PM10) measured at fixed sites within the study areas.Positive associations were found between the average PM10concentration and the prevalence of phlegm (OR per 10 μg·m−31.15, 95% CI 1.02–1.30), hay fever (OR 1.20, 95% CI 0.99–1.46), bronchitis (OR 1.08, 95% CI 0.98–1.19), morning cough (OR 1.15, 95% CI 1.02–1.29) and nocturnal cough (OR 1.13, 95% CI 0.98–1.29). There were no associations with diagnosed asthma or asthma symptoms. PM10was not associated with lung function across all studies combined.Our study adds to the evidence that long-term exposure to outdoor air pollution, characterised by the concentration of PM10, is associated with increased respiratory symptoms.