9,529 research outputs found

    IsaB Inhibits Autophagic Flux to Promote Host Transmission of Methicillin-Resistant Staphylococcus aureus.

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    Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major nosocomial pathogen that is widespread in both health-care facilities and in the community at large, as a result of direct host-to-host transmission. Several virulence factors are associated with pathogen transmission to naive hosts. Immunodominant surface antigen B (IsaB) is a virulence factor that helps Staphylococcus aureus to evade the host defense system. However, the mechanism of IsaB on host transmissibility remains unclear. We found that IsaB expression was elevated in transmissible MRSA. Wild-type isaB strains inhibited autophagic flux to promote bacterial survival and elicit inflammation in THP-1 cells and mouse skin. MRSA isolates with increased IsaB expression showed decreased autophagic flux, and the MRSA isolate with the lowest IsaB expression showed increased autophagic flux. In addition, recombinant IsaB rescued the virulence of the isaB deletion strain and increased the group A streptococcus (GAS) virulence in vivo. Together, these results reveal that IsaB diminishes autophagic flux, thereby allowing MRSA to evade host degradation. These findings suggest that IsaB is a suitable target for preventing or treating MRSA infection

    Fiber-coupled light-emitting diode with a capillary-bonded hemispherical lens

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    A hemispherical lens capillary-bonded to an InGaN flip-chip light-emitting diode (LED) is demonstrated to efficiently couple light to a plastic optical fiber. The BK-7 hemispherical lens is bonded onto a circularly shaped LED chip with inclined sidewalls cut by laser-micromachining, so that lateral emissions are effectively suppressed. Capillary bonding minimizes air-gap between chip and lens enabling transmission of evanescent waves, thus maximizing overall optical transmission. With the lens attached, emission divergence from the assembly is significantly reduced, diverting rays into the acceptance cone of the fiber. Fiber coupling efficiency as high as 53.8% has been demonstrated. © 2011 IEEE.published_or_final_versio

    Exercise-Induced Changes in Exhaled NO Differentiates Asthma With or Without Fixed Airway Obstruction From COPD With Dynamic Hyperinflation.

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    Asthmatic patients with fixed airway obstruction (FAO) and patients with chronic obstructive pulmonary disease (COPD) share similarities in terms of irreversible pulmonary function impairment. Exhaled nitric oxide (eNO) has been documented as a marker of airway inflammation in asthma, but not in COPD. To examine whether the basal eNO level and the change after exercise may differentiate asthmatics with FAO from COPD, 27 normal subjects, 60 stable asthmatics, and 62 stable COPD patients were studied. Asthmatics with FAO (n = 29) were defined as showing a postbronchodilator FEV(1)/forced vital capacity (FVC) ≤70% and FEV(1) less than 80% predicted after inhaled salbutamol (400 μg). COPD with dynamic hyperinflation (n = 31) was defined as a decrease in inspiratory capacity (ΔIC%) after a 6 minute walk test (6MWT). Basal levels of eNO were significantly higher in asthmatics and COPD patients compared to normal subjects. The changes in eNO after 6MWT were negatively correlated with the percent change in IC (r = −0.380, n = 29, P = 0.042) in asthmatics with FAO. Their levels of basal eNO correlated with the maximum mid-expiratory flow (MMEF % predicted) before and after 6MWT. In COPD patients with air-trapping, the percent change of eNO was positively correlated to ΔIC% (rs = 0.404, n = 31, P = 0.024). We conclude that asthma with FAO may represent residual inflammation in the airways, while dynamic hyperinflation in COPD may retain NO in the distal airspace. eNO changes after 6MWT may differentiate the subgroups of asthma or COPD patients and will help toward delivery of individualized therapy for airflow obstruction

    Damage identification of supporting structures with a moving sensory system

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    © 2017 Elsevier Ltd An innovative approach to identify local anomalies in a structural beam bridge with an instrumented vehicle moving as a sensory system across the bridge. Accelerations at both the axle and vehicle body are measured from which vehicle-bridge interaction force on the structure is determined. Local anomalies of the structure are estimated from this interaction force with the Newton's iterative method basing on the homotopy continuation method. Numerical results with the vehicle moving over simply supported or continuous beams show that the acceleration responses from the vehicle or the bridge structure are less sensitive to the local damages than the interaction force between the wheel and the structure. Effects of different movement patterns and moving speed of the vehicle are investigated, and the effect of measurement noise on the identified results is discussed. A heavier or slower vehicle has been shown to be less sensitive to measurement noise giving more accurate results

    Cross-sectional difference in BMI between senior and junior students predicts prospective change in BMI at the school level

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    Poster Presentation: abstract no. 1196The Conference abstracts's website is located at http://www2.kenes.com/apccn/scientific/Pages/ListofAbstracts.aspxOBJECTIVES: To examine whether cross-sectional BMI difference between senior and junior secondary school students was correlated with prospective changes in BMI at the school level. BACKGROUND: Schools are known to exert prospective influences on adolescent BMI. The school effects may also be reflected in cross-sectional BMI differences between senior and junior students in each school. Schools could quickly be identified for weight-control interventions if such cross-sectional differences could predict prospective changes in BMI. METHODS: In the Hong Kong Student …postprin

    Alcohol consumption and sleep problems in Hong Kong adolescents

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    Independent association between parental smoking and non-authoritative parenting style as reported by Chinese adolescents in Hong Kong

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    Poster Discussion 35. Engaging New Partners: no. PD-1005-20Conference Theme: Tobacco and Non-Communicable DiseasesBACKGROUND: Both parental smoking and non-authoritative parenting style predict adolescent smoking, but the association between the two risk factors was seldom studied. We investigated this association in Chinese parents of adolescents in Hong Kong, where smoking is socially undesirable, especially in females. DESIGN/METHODS: In the Hong Kong Student Obesity Surveillance project 2006/07, 33692 adolescents aged 11-18 (44.9% boys, mean age 14.8, SD 1.9 years) from 42 randomly selected schools reported smoking status (yes vs no) and the level (frequent/sometimes as high; seldom/none as low) of care and control of each parent. Parenting style (dependent variable) was defined as authoritative …published_or_final_versio

    A School-based Survey on Adolescent Alcohol Drinking in Hong Kong

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    Symposium Theme: Translating Health Research into Policy and Practice for Health of the PopulationParallel Session 1 - Population Health & Policy: no. S2INTRODUCTION: The effective control of underage drinking requires a thorough understanding of its risk factors and effects, but little is known about the drinking pattern in Hong Kong adolescents. OBJECTIVES: We investigated the drinking pattern and associated risk factors and problems in Hong Kong secondary school students. METHODS: In a territory-wide survey of 44 randomly selected schools, 21627 Secondary 1 to 6 students (mean age 14.7, SD 1.8; 51.6% boys) provided valid data using an anonymous questionnaire in 2012-13. Data on socio-demographic characteristics, alcohol drinking, peer and co-residents’ drinking, exposure to pro-drinking and anti-drinking messages, parental pro-drinking practices and health outcomes were collected. Descriptive data were weighted by sex, age and grade distribution of students in Hong Kong. Risk factors and problems associated with adolescent drinking were …published_or_final_versio
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