Antimicrobial Air Filters Using Natural Euscaphis japonica Nanoparticles

Controlling bioaerosols has become more important with increasing participation in indoor activities. Treatments using natural-product nanomaterials are a promising technique because of their relatively low toxicity compared to inorganic nanomaterials such as silver nanoparticles or carbon nanotubes. In this study, antimicrobial filters were fabricated from natural Euscaphis japonica nanoparticles, which were produced by nebulizing E. japonica extract. The coated filters were assessed in terms of pressure drop, antimicrobial activity, filtration efficiency, major chemical components, and cytotoxicity. Pressure drop and antimicrobial activity increased as a function of nanoparticle deposition time (590, 855, and 1150 µg/cm2_filter at 3-, 6-, and 9-min depositions, respectively). In filter tests, the antimicrobial efficacy was greater against Staphylococcus epidermidis than Micrococcus luteus; ~61, ~73, and ~82% of M. luteus cells were inactivated on filters that had been coated for 3, 6, and 9 min, respectively, while the corresponding values were ~78, ~88, and ~94% with S. epidermidis. Although statistically significant differences in filtration performance were not observed between samples as a function of deposition time, the average filtration efficacy was slightly higher for S. epidermidis aerosols (~97%) than for M. luteus aerosols (~95%). High-performance liquid chromatography (HPLC) and electrospray ionization-tandem mass spectrometry (ESI/MS) analyses confirmed that the major chemical compounds in the E. japonica extract were 1(ß)-O-galloyl pedunculagin, quercetin-3-O-glucuronide, and kaempferol-3-O-glucoside. In vitro cytotoxicity and disk diffusion tests showed that E. japonica nanoparticles were less toxic and exhibited stronger antimicrobial activity toward some bacterial strains than a reference soluble nickel compound, which is classified as a human carcinogen. This study provides valuable information for the development of a bioaerosol control system that is environmental friendly and suitable for use in indoor environments.     

64Cu-ATSM Hypoxia Positron Emission Tomography for Detection of Conduit Ischemia in an Experimental Rat Esophagectomy Model

Background

We designed a hypoxia-imaging modality to detect ischemia of the gastric conduit after esophagectomy.

Materials and Methods

A rat esophagectomy model was created using 12-16-week-old, 300-350 g male Sprague-Dawley rats. In the operation group (n=6), partial gastric devascularization was performed by ligating the left gastric artery and the short gastric arteries and an esophagogastric anastomosis was performed. In the control group (n=6), the esophageal-gastric junction was incised and suturing was performed without gastric devascularization. Positron emission tomography (PET) images were taken using a microPET rodent model scanner, 24 h after the initial operation, after injection of 200 μCi 64Cu-diacetyl-bis (N4-methylsemicarbazone) (64Cu-ATSM) and pimonidazole 120 mg/kg. After microPET imaging, autoradiography and immunohistochemistry were performed.

Results

The PET image revealed 64Cu-ATSM uptake at the fundus in the operation group 3 h after 64Cu-ATSM injection. The maximum percentage of the injected dose per gram of tissue was higher in the operation group (0.047±0.015 vs. 0.026±0.006, p=0.021). The fundus/liver ratio was also higher in the operation group (0.541±0.126 vs. 0.278±0.049, p=0.002). Upon autoradiography, 64Cu-ATSM uptake was observed in the fundus in the operation group, and was well-correlated to that observed on the PET image. Upon immunohistochemistry, expression of hypoxia-inducible factor 1a and pimonidazole were significantly increased at the fundus and lesser curvature compared to the greater curvature in the operation group.

Conclusion

Hypoxia PET imaging with 64Cu-ATSM can detect ischemia in a rat esophagectomy model. Further clinical studies are needed to verify whether hypoxia imaging may be useful in humans.     

Factors that Predict Negative Results of QuantiFERON-TB Gold In-Tube Test in Patients with Culture-Confirmed Tuberculosis: A Multicenter Retrospective Cohort Study

Background

Interferon-γ release assays such as the QuantiFERON-TB Gold In-Tube Test (QFT-GIT) are designed to detect Mycobacterium tuberculosis infections, whether latent or manifesting as disease. However, a substantial number of persons with culture-confirmed tuberculosis (TB) have negative QFT-GITs. Information on host factors contributing to false-negative and indeterminate results are limited.

Methods

A multicenter retrospective cohort study was performed with 1,264 culture-confirmed TB patients older than 18 years who were subjected to the QFT-GIT at one of the six hospitals between May 2007 and February 2014. Patients with human immunodeficiency virus infection were excluded. Clinical and laboratory data were collected in South Korea.

Results

Of all patients, 87.6% (1,107/1,264) were diagnosed with pulmonary TB and 12.4% (157/1,264) with extrapulmonary TB. The rate of negative results was 14.4% (182/1,264). The following factors were highly correlated with false-negative results in the QFT-GIT: advanced age (age ≥ 65 years, odds ratio [OR] 1.57, 95% confidence interval [CI] 1.03–2.39), bilateral disease as determined by chest radiography (OR 1.75, 95% CI 1.13–2.72), malignancy (OR 2.42, 95% CI 1.30–4.49), and lymphocytopenia (total lymphocyte count < 1.0 × 10⁹/L, OR 1.86, 95% CI 1.21–2.87).

Conclusions

Consequently, QFT-GIT results need to be interpreted with caution in patients with these host risk factors such as the elderly, bilateral disease on chest radiography, or malignancy, or lymphocytopenia.     

Effect of cubic phase nanoparticle on obesity-suppressing efficacy of herbal extracts

The adipocyte differentiation-inhibiting efficacies of cubic phase nanoparticle/herbal extract mixture suspensions were much higher than those of herbal extract suspensions (grape, apple, mugwort, barberry root, and green tea). Confocal laser scanning microscopy and fluorescenceactivated cell sorting analysis revealed that cubic phase nanoparticle promoted the internalization of a watersoluble dye (e.g. calcein) into adipocyte cell. Cubic phase nanoparticle/herbal extract mixture suspensions decreased the blood contents of aspartate aminotransferase, total cholesterol, triglyceride, urea nitrogen, and low density lipoprotein more than herbal extract suspensions. Cubic phase nanoparticle also promoted the efficacy of the herbal extracts in suppressing the body weight gain and the liver weight of rats. The amount permeated through hairless mouse skin was higher when cubic phase nanoparticle was included in barberry root extract suspension.     

2006～2014年柳州市重大道路交通事故流行病学特征分析

目的调查分析柳州市重大道路交通事故发生的特点及规律,为控制和预防道路交通创伤提供科学依据。方法回顾性分析2006~2014年柳州市重大道路交通事故监测统计资料。结果 (1)2006~2014年柳州市重大道路交通事故发生例数、死亡人数、受伤人数呈总体下降趋势。以1月份发生事故最多,占事故总数的11.5%;6月份发生事故最少,为6.8%。夜间19:00~23:00时事故发生最多,凌晨3:00~6:00时发生最少。(2)重大道路交通事故多数发生在平直道路上。(3)白天发生事故最多,夜间无路灯照明的路段事故伤亡和受伤人数明显高于夜间有路灯照明的路段。(4)重大道路交通事故发生的主要原因为人为因素,占总数的96.7%。结论减少重大道路交通事故发生,必须加强交通安全宣传、教育,提高全民安全意识;交管部门严格执法,尤其要加强交通事故高发时段、路段的管理;加强道路安全设施建设,改善交通环境。     

土著昆虫素毒蛾对入侵植物互花米草地理种群的选择性

外来植物入侵后会改变其对入侵地植食性昆虫的防御能力以应对入侵地生物环境的变化,因此,对土著昆虫防御能力变化的研究将有助于解释外来植物成功入侵的机制。互花米草(Spartina alterniflora)是广泛入侵中国东部沿海地区的外来植物,研究其入侵后对本地植食性昆虫的响应,可从一个侧面部分地回答其成功入侵的生态机制。利用Y型嗅觉仪,结合室内取食实验,我们比较了中国的土著昆虫素毒蛾(Laelia coenosa)对互花米草3个原产地种群和5个入侵地种群的选择偏好,这些种群分别来自美国的德克萨斯(Texas Point)、卡纳维拉尔国家海岸(Canaveral National Seashore)、佛罗里达大西洋大学(Florida Atlantic University),以及中国的唐海、天津、盐城、崇明、珠海。结果表明,虽然素毒蛾幼虫对互花米草不同地理种群叶片气味没有显著的选择偏好,但对原产地种群的取食相对选择系数显著高于入侵地种群,说明互花米草入侵地种群对素毒蛾的抵抗能力相对较强。这从某种层面上可以推测互花米草入侵中国东部沿海地区以后,其对植食性昆虫取食的防御能力有所增强,而这种能力将在一定程度上减少素毒蛾等入侵地植食动物对它的攻击。     

First Report of Myrothecium roridum Causing Leaf Spot on Anthurium andraeanum in China

A new severe disease on Anthurium andraeanum Lind. was observed in the summer of 2011 in Beijing, China. The fungus was isolated from symptomatic leaves, and its pathogenicity was confirmed. Based on the morphological characteristics and molecular analysis, the pathogen was identified as Myrothecium roridum Tode ex Fr. This is the first report of M. roridum causing leaf spot on A. andraeanum in China.     

THO2, a core member of the THO/TREX complex,is required for microRNA production in Arabidopsis

The THO/TREX complex mediates transport of nascent mRNAs from the nucleus towards the cytoplasm in animals, and has a role in small interfering RNA‐dependent processes in plants. Here we describe five mutant alleles of Arabidopsis thaliana THO2, which encodes a core subunit of the plant THO/TREX complex. tho2 mutants present strong developmental defects resembling those in plants compromised in microRNA (miRNA) activity. In agreement, not only were the levels of siRNAs reduced in tho2 mutants, but also those of mature miRNAs. As a consequence, a feedback mechanism is triggered, increasing the amount of miRNA precursors, and finally causing accumulation of miRNA‐targeted mRNAs. Yeast two‐hybrid experiments and confocal microscopy showed that THO2 does not appear to interact with any of the known miRNA biogenesis components, but rather with the splicing machinery, implying an indirect role of THO2 in small RNA biogenesis. Using an RNA immunoprecipitation approach, we found that THO2 interacts with miRNA precursors, and that tho2 mutants fail to recruit such precursors into the miRNA‐processing complex, explaining the reduction in miRNA production in this mutant background. We also detected alterations in the splicing pattern of genes encoding serine/arginine‐rich proteins in tho2 mutants, supporting a previously unappreciated role of the THO/TREX complex in alternative splicing.