Association between the First Occurrence of Asthma and Residential Greenness in Children and Teenagers in Taiwan.

Green spaces have benefits but may also increase the risk of allergic disease. This study examined the association between the first occurrence of asthma and greenness exposure in children and teenagers. We conducted a 1:1 matched case-control study matched by sex, age, and the first diagnosis year with 7040 eligible subjects from a systematic sampling cohort database in Taiwan from 2001 to 2013. A normalized difference vegetation index (NDVI) value ≥0.4 was used as the criterion to determine the green space. The green cover images were then transformed to the green coverage rate in the township surrounding the residential areas of the asthma and control subjects. Conditional logistic regression analyses demonstrated that a significantly increased risk of asthma in preschool children was associated with the surrounding greenness after adjusting for urbanization level, frequency of healthcare provider visits, mean township family income, CO, NOx, and PM2.5. The risk of asthma occurrence increased significantly with increasing greenness exposure (p-trend < 0.05). Nevertheless, exposure to the highest greenness levels (81-100%) was not associated with a significantly higher risk of asthma occurrence than was exposure to the lowest values (0-20%) of greenness. This study suggests that green space design should consider more effective methods of reducing the allergy impact.

Altered susceptibility to air sampling stress by filtration is related to colistin resistance development in Acinetobacter baumannii.

The accurate quantification of antibiotic-resistant bacteria in indoor air has recently attracted increasing attention. Here, we investigated whether the susceptibility of a nosocomial infection-related microbe, Acinetobacter baumannii, to strong sampling stress caused by Nuclepore filter changes as it develops resistance to a drug called colistin. Both colistin-sensitive A. baumannii (CSAB) and colistin-resistant A. baumannii (CRAB) are generally desiccation-resistant strains that can be collected by filter sampling. However, the resistance of CRAB to the three combined stresses (aerosolization, impaction, and desiccation) caused by filter sampling was 1.8 times lower than that of CSAB (P < 0.05). The sampling stresses caused by filter sampling not only reduced the culturability of A. baumannii but also destroyed proteins to result in cellular protein leakage. CRAB released 17%-38% more extracellular protein than did CSAB when they were both subjected to desiccation stress for 240 minutes (P < 0.01). The combination of using a sampling flow rate of 20 L/min and sampling for 60 minutes with a Nuclepore filter with open-face cassettes (OFCs) is recommended for collecting airborne A. baumannii. A Nuclepore filter operated with closed-face cassettes (CFCs) significantly decreased the culturability of CRAB due to desiccation effects.

Clinical Antibiotic-resistant Acinetobacter baumannii Strains with Higher Susceptibility to Environmental Phages than Antibiotic-sensitive Strains.

Antibiotic-resistant Acinetobacter baumannii is associated with nosocomial infections worldwide. Here, we used clinically isolated A. baumannii strains as models to demonstrate whether antibiotic resistance is correlated with an increased susceptibility to bacteriophages. In this study, 24 active phages capable of infecting A. baumannii were isolated from various environments, and the susceptibilities of both antibiotic-sensitive and antibiotic-resistant strains of A. baumannii to different phages were compared. In our study, a total of 403 clinically isolated A. baumannii strains were identified. On average, the phage infection percentage of the antibiotic-resistant A. baumannii strains was 84% (from 81-86%), whereas the infection percentage in the antibiotic-sensitive A. baumannii strains was only 56.5% (from 49-64%). In addition, the risk of phage infection for A. baumannii was significantly increased in the strains that were resistant to at least four antibiotics and exhibited a dose-dependent response (p-trend < 0.0001). Among all of the A. baumannii isolates, 75.6% were phage typeable. The results of phage typing might also reveal the antibiotic-resistant profiles of clinical A. baumannii strains. In conclusion, phage susceptibility represents an evolutionary trade-off in A. baumannii strains that show adaptations for antibiotic resistance, particularly in medical environments that have high antibiotic use.

Direct synthesis of solvent-free multiwall carbon nanotubes/silica nonionic nanofluid hybrid material.

The solvent-free nonionic nanofluid hybrid material consisting of multiwall carbon nanotubes (MWNTs) and silica nanoparticles is prepared by a facile route. The content of MWNTs/silica nanoparticles is up to 31 wt %. The hybrid material exhibits liquid-like behavior in the absence of solvent at 45 degrees C, which is a wax solid at room temperature. The process of melting and solidification is reversible over many cycles.

G protein-coupled receptor kinase 4 gene variants in human essential hypertension.

Essential hypertension has a heritability as high as 30-50%, but its genetic cause(s) has not been determined despite intensive investigation. The renal dopaminergic system exerts a pivotal role in maintaining fluid and electrolyte balance and participates in the pathogenesis of genetic hypertension. In genetic hypertension, the ability of dopamine and D(1)-like agonists to increase urinary sodium excretion is impaired. A defective coupling between the D(1) dopamine receptor and the G protein/effector enzyme complex in the proximal tubule of the kidney is the cause of the impaired renal dopaminergic action in genetic rodent and human essential hypertension. We now report that, in human essential hypertension, single nucleotide polymorphisms of a G protein-coupled receptor kinase, GRK4gamma, increase G protein-coupled receptor kinase (GRK) activity and cause the serine phosphorylation and uncoupling of the D(1) receptor from its G protein/effector enzyme complex in the renal proximal tubule and in transfected Chinese hamster ovary cells. Moreover, expressing GRK4gammaA142V but not the wild-type gene in transgenic mice produces hypertension and impairs the diuretic and natriuretic but not the hypotensive effects of D(1)-like agonist stimulation. These findings provide a mechanism for the D(1) receptor coupling defect in the kidney and may explain the inability of the kidney to properly excrete sodium in genetic hypertension.