Exopolysaccharide protects Vibrio cholerae from exogenous attacks by the type 6 secretion system

The type 6 secretion system (T6SS) is a nanomachine used by many Gram-negative bacteria, including Vibrio cholerae, to deliver toxic effector proteins into adjacent eukaryotic and bacterial cells. Because the activity of the T6SS is dependent on direct contact between cells, its activity is limited to bacteria growing on solid surfaces or in biofilms. V. cholerae can produce an exopolysaccharide (EPS) matrix that plays a role in adhesion and biofilm formation. In this work, we investigated the effect of EPS production on T6SS activity between cells. We found that EPS produced by V. cholerae cells functions as a unidirectional protective armor that blocks exogenous T6SS attacks without interfering with its own T6SS functionality. This EPS armor is effective against both samespecies and heterologous attackers. Mutations modulating the level of EPS biosynthesis gene expression result in corresponding modulation in V. cholerae resistance to exogenous T6SS attack. These results provide insight into the potential role of extracellular biopolymers, including polysaccharides, capsules, and S-layers in protecting bacterial cells from attacks involving cell-associated macromolecular protein machines that cannot readily diffuse through these mechanical defenses

Characterization of volatile organic compounds at a roadside environment in Hong Kong: An investigation of influences after air pollution control strategies

Vehicular emission is one of the important anthropogenic pollution sources for volatile organic compounds (VOCs). Four characterization campaigns were conducted at a representative urban roadside environment in Hong Kong between May 2011 and February 2012. Carbon monoxide (CO) and VOCs including methane (CH4), non-methane hydrocarbons (NMHCs), halocarbons, and alkyl nitrates were quantified. Both mixing ratios and compositions of the target VOCs show ignorable seasonal variations. Except CO, liquefied petroleum gas (LPG) tracers of propane, i-butane and n-butane are the three most abundant VOCs, which increased significantly as compared with the data measured at the same location in 2003. Meanwhile, the mixing ratios of diesel- and gasoline tracers such as ethyne, alkenes, aromatics, halogenated, and nitrated hydrocarbons decreased by at least of 37%. The application of advanced multivariate receptor modeling technique of positive matrix factorization (PMF) evidenced that the LPG fuel consumption is the largest pollution source, accounting for 60 ± 5% of the total quantified VOCs at the roadside location. The sum of ozone formation potential (OFP) for the target VOCs was 300.9 μg-O3 m-3, which was 47% lower than the value of 567.3 μg-O3 m-3 measured in 2003. The utilization of LPG as fuel in public transport (i.e., taxis and mini-buses) contributed 51% of the sum of OFP, significantly higher than the contributions from gasoline- (16%) and diesel-fueled (12%) engine emissions. Our results demonstrated the effectiveness of the switch from diesel to LPG-fueled engine for taxis and mini-buses implemented by the Hong Kong Special Administrative Region (HKSAR) Government between the recent ten years, in additional to the execution of substitution to LPG-fueled engine and restrictions of the vehicular emissions in compliance with the updated European emission standards

Reactions to Thirdhand Smoke are Associated with Openness to Smoking in Young Never Smoking Children

To investigate the associations between reactions to thirdhand smoke (THS) and openness to smoking in young children. In a school-based survey in Hong Kong, 4762 Chinese primary school students reported their reactions to THS (one or more of ‘pleasant/happy’, ‘nausea’, ‘excited’, ‘heart beat faster’, ‘relaxed’, ‘dislike the smell’, ‘like the smell’, ‘dizzy’, ‘coughing/choking’, ‘eye uncomfortable’ and ‘none of the above’), smoking status and openness to smoking (lack of a firm intention not to smoke). Factor structure of reactions to THS was investigated with factor scores calculated and categorised. Logistic regression yielded adjusted odds ratio (AOR) of openness to smoking for reactions to THS. Factor analysis yielded two factors including 5 and 4 reactions, which were generally deemed negative and positive, respectively. The proportions of students with factor scores ≥1 for negative and positive reactions were 51.3 and 6.3 %, respectively. In never smokers, openness to smoking was negatively associated with ‘dislike the smell’ (AOR 0.52, 95 % CI 0.39–0.68), ‘coughing/choking’ (0.53, 0.38–0.75), ‘eye uncomfortable’ (0.62, 0.40–0.95) and negative reaction factor score of 2–5 (vs. 0) (0.59, 0.40–0.88), and was positively associated with ‘pleasant/happy’ (2.80, 1.54–5.09), ‘excited’ (2.83, 1.17–6.87), ‘like the smell’ (3.06, 1.49–6.26) and positive reaction factor score of 1–4 (vs. 0) (2.86, 1.83–4.48). In experimental or former smokers, fewer associations reached statistical significance. Negative and positive reactions to THS were negatively and positively associated with openness to smoking, respectively, in young never smoking children.postprin

Continuous positive airway pressure (CPAP) to treat respiratory distress in newborns in low- and middle-income countries.

Severe respiratory distress is a serious complication common to the three major causes of neonatal mortality and morbidity (prematurity, intra-partum-related hypoxia and infections). In low- and middle-income countries (LMICs), 20% of babies presenting with severe respiratory distress die.Continuous positive airway pressure (CPAP), is an effective intervention for respiratory distress in newborns and widely used in high-income countries. Following the development of simple, safe and relatively inexpensive CPAP devices, there is potential for large-scale implementation in the developing world.In this article, we describe existing CPAP systems and present a review of the current literature examining the effectiveness of CPAP compared to standard care (oxygen) in newborns with respiratory distress. We also discuss the evidence gap which needs to be addressed prior to its integration into health systems in LMICs

Continuation of dabigatran therapy in "real-world" practice in Hong Kong

Background: Dabigatran, an oral direct thrombin inhibitor, possesses several advantages over warfarin that can in principle simplify the management of stroke prevention in atrial fibrillation (AF). Nonetheless it remains unclear whether these advantages can translate to clinical practice and encourage long-term therapy. The objective was to describe long-term dabigatran therapy for stroke prevention in AF and to identify risk factors for discontinuation of therapy. Methods and Results: We studied 467 consecutive Chinese patients (72±11 years, male: 53.8%) with a mean CHA2DS2-VASc score of 3.6 prescribed dabigatran for stroke prevention in AF from March 2010 to September 2013. Over a mean follow-up of 16 months, 101 patients (21.6%) permanently discontinued dabigatran. The mean time-to-discontinuation was 8 months. The most common reason for discontinuation was dyspepsia (30.7%), followed by other adverse events (17.8%) such as minor bleeding (8.9%), major gastrointestinal bleeding (7.9%), and intracranial hemorrhage (1%). Other reasons included dosing frequency (5.9%), fear of side effects (4.0%), lack of laboratory monitoring (1.0%), and cost (1.0%). Multivariable analysis revealed that low baseline estimated glomerular filtration rate (p = 0.02), absence of hypertension (p= 0.01), and prior use of a proton-pump inhibitor (p = 0.02) and H2-receptor blocker (p = 0.01) were independent predictors of drug discontinuation. In addition, there were altogether 9 ischemic strokes (1.5%/years), 3 intracranial hemorrhages (0.5%/year), and 24 major gastrointestinal bleedings (4.1%/year). Conclusion: Dabigatran discontinuation is very common amongst Chinese AF patients. This reveals a management gap in the prevention of stroke in AF. © 2014 Ho et al.published_or_final_versio

Randomized controlled trial of a good practice approach to treatment of childhood obesity in Malaysia: Malaysian childhood obesity treatment trial (MASCOT)

Context. Few randomized controlled trials (RCTs) of interventions for the treatment of childhood obesity have taken place outside the Western world. Aim. To test whether a good practice intervention for the treatment of childhood obesity would have a greater impact on weight status and other outcomes than a control condition in Kuala Lumpur, Malaysia. Methods. Assessor-blinded RCT of a treatment intervention in 107 obese 7- to 11-year olds. The intervention was relatively low intensity (8 hours contact over 26 weeks, group based), aiming to change child sedentary behavior, physical activity, and diet using behavior change counselling. Outcomes were measured at baseline and six months after the start of the intervention. Primary outcome was BMI z-score, other outcomes were weight change, health-related quality of life (Peds QL), objectively measured physical activity and sedentary behavior (Actigraph accelerometry over 5 days). Results. The intervention had no significant effect on BMI z score relative to control. Weight gain was reduced significantly in the intervention group compared to the control group (+1.5 kg vs. +3.5 kg, respectively, t-test p < 0.01). Changes in health-related quality of life and objectively measured physical activity and sedentary behavior favored the intervention group. Conclusions. Treatment was associated with reduced rate of weight gain, and improvements in physical activity and quality of life. More substantial benefits may require longer term and more intensive interventions which aim for more substantive lifestyle changes

Lung cancer tumorigenicity and drug resistance are maintained through ALDH(hi)CD44(hi) tumor initiating cells

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Developmental changes in the role of different metalinguistic awareness skills in Chinese reading acquisition from preschool to third grade

Copyright @ 2014 Wei et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The present study investigated the relationship between Chinese reading skills and metalinguistic awareness skills such as phonological, morphological, and orthographic awareness for 101 Preschool, 94 Grade-1, 98 Grade-2, and 98 Grade-3 children from two primary schools in Mainland China. The aim of the study was to examine how each of these metalinguistic awareness skills would exert their influence on the success of reading in Chinese with age. The results showed that all three metalinguistic awareness skills significantly predicted reading success. It further revealed that orthographic awareness played a dominant role in the early stages of reading acquisition, and its influence decreased with age, while the opposite was true for the contribution of morphological awareness. The results were in stark contrast with studies in English, where phonological awareness is typically shown as the single most potent metalinguistic awareness factor in literacy acquisition. In order to account for the current data, a three-stage model of reading acquisition in Chinese is discussed.National Natural Science Foundation of China and Knowledge Innovation Program of the Chinese Academy of Sciences

Summer and winter variations of dicarboxylic acids, fatty acids and benzoic acid in PM₂.₅ in Pearl Delta River Region, China

Author name used in this publication: Lee, S. C.2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe