Performance of the Interferon Gamma Release Assays in Tuberculosis Disease in Children Five Years Old or Less

Interferon Gamma Release Assays (IGRAs) were developed for the indirect or immunologic diagnosis of tuberculosis infection; however, they have also been used to assist in difficult to diagnose cases of tuberculosis disease in adults, and to a lesser extent, in children, especially in those under 5 years old. We evaluated the utility of using an IGRA in pediatric tuberculosis in younger children in a hospital setting. The diagnostic accuracy of T-SPOT.TB and TST was assessed in 117 children with active tuberculosis and 413 children with respiratory tract infection. Sensitivity and specificity were calculated for the tests used individually and together. Concordance was also calculated. Sensitivity of T-SPOT.TB (82.9%) was higher than TST (78.6% using a 5mm cut-off), especially in children confirmed to have TB. T-SPOT.TB was more specific than TST using a 5mm cut-off (96.1% vs. 70.9%). Combining T-SPOT.TB and TST results improved the sensitivity to 96.6%. In conclusion, the results of the current study indicate that T-SPOT.TB has good sensitivity and specificity, supporting its use among patients of this age. A combination of IGRA and TST would be useful additions to assist in the diagnosis of childhood TB.     

Albumin and Neutrophil Combined Prognostic Grade as a New Prognostic Factor in Non-Small Cell Lung Cancer: Results from a Large Consecutive Cohort

Objectives

It has been reported nutritional status and systemic inflammation were associated with the outcome of patients with malignancies. However, the prognostic value of combination of them was really scarce, especially in non-small cell lung cancer (NSCLC). In order to find a more simple and efficient predictor, we hypothesized that pretreatment albumin and neutrophil combined prognostic grade (ANPG) could offer an improved prognostic ability in NSCLC patients.

Methods

We collected pretreatment albumin and neutrophil, clinicopathological, treatment and follow-up data of 1033 consecutive NSCLC patients treated between 2006 and 2011 in this retrospective study. The ANPG was calculated according to pretreatment albumin and neutrophil levels dichotomized by the optimal cut-off values, the quartile values and the clinical reference values. Kaplan-Meier (K-M) curves and Cox proportional regression were used for survival analyses. All the data was analyzed by SPSS 20.0.

Results

According to optimal cut-off values and quartile values, significant differences were found in different pretreatment albumin, neutrophil levels and ANPG from the K-M curve (all p<0.05). Univariate analyses and multivariate analyses disclosed ANPG was a more sensitive independent predictor for both overall survival (OS) and progression free survival (PFS) than either albumin level or neutrophil level (HRs were higher for ANPG). As for clinical reference values, no significant difference of pretreatment albumin levels was found in K-M curve and univariate analyses. All three indexes lost their significance in multivariate analyses.

Conclusion

Higher ANPG predicts worse OS and PFS in NSCLC patients independently, and it is more sensitive than hypoalbuminaemia and neutrophilia. It might be used as a reliable, convenient and more sensitive predictor to assist the identification of patients with poor prognosis and be a hierarchical factor in the future NSCLC clinical trials.     

Experimental and Natural Infections of Goats with Severe Fever with Thrombocytopenia Syndrome Virus: Evidence for Ticks as Viral Vector

Background

Severe fever with thrombocytopenia syndrome virus (SFTSV), the causative agent for the fatal life-threatening infectious disease, severe fever with thrombocytopenia syndrome (SFTS), was first identified in the central and eastern regions of China. Although the viral RNA was detected in free-living and parasitic ticks, the vector for SFTSV remains unsettled.

Methodology/Principal Findings

Firstly, an experimental infection study in goats was conducted in a bio-safety level-2 (BSL-2) facility to investigate virus transmission between animals. The results showed that infected animals did not shed virus to the outside through respiratory or digestive tract route, and the control animals did not get infected. Then, a natural infection study was carried out in the SFTSV endemic region. A cohort of naïve goats was used as sentinel animals in the study site. A variety of daily samples including goat sera, ticks and mosquitoes were collected for viral RNA and antibody (from serum only) detection, and virus isolation. We detected viral RNA from free-living and parasitic ticks rather than mosquitoes, and from goats after ticks’ infestation. We also observed sero-conversion in all members of the animal cohort subsequently. The S segment sequences of the two recovered viral isolates from one infected goat and its parasitic ticks showed a 100% homology at the nucleic acid level.

Conclusions/Significance

In our natural infection study, close contact between goats does not appear to transmit SFTSV, however, the naïve animals were infected after ticks’ infestation and two viral isolates derived from an infected goat and its parasitic ticks shared 100% of sequence identity. These data demonstrate that the etiologic agent for goat cohort’s natural infection comes from environmental factors. Of these, ticks, especially the predominant species Haemaphysalis longicornis, probably act as vector for this pathogen. The findings in this study may help local health authorities formulate and focus preventive measures to contain this infection.     

Wind‐mediated horseweed (Conyza canadensis) gene flow: pollen emission,dispersion, and deposition

Horseweed (Conyza canadensis) is a problem weed in crop production because of its evolved resistance to glyphosate and other herbicides. Although horseweed is mainly self-pollinating, glyphosate-resistant (GR) horseweed can pollinate glyphosate-susceptible (GS) horseweed. To the best of our knowledge, however, there are no available data on horseweed pollen production, dispersion, and deposition relative to gene flow and the evolution of resistance. To help fill this knowledge gap, a 43-day field study was performed in Champaign, Illinois, USA in 2013 to characterize horseweed atmospheric pollen emission, dispersion, and deposition. Pollen concentration and deposition, coupled with atmospheric data, were measured in a source field (180 m by 46 m) and its surrounding areas up to 1 km downwind horizontally and up to 100 m vertically. The source strength (emission rate) ranged from 0 to 140 pollen grains per plant per second (1170 to 2.1×10⁶ per plant per day). For the life of the study, the estimated number of pollen grains generated from this source field was 10.5×10¹⁰ (2.3×10⁶ per plant). The release of horseweed pollen was not strongly correlated to meteorological data and may be mainly determined by horseweed physiology. Horseweed pollen reached heights of 80 to100 m, making long-distance transport possible. Normalized (by source data) pollen deposition with distance followed a negative-power exponential curve. Normalized pollen deposition was 2.5% even at 480 m downwind from the source edge. Correlation analysis showed that close to or inside the source field at lower heights (≤3 m) vertical transport was related to vertical wind speed, while horizontal pollen transport was related to horizontal wind speed. High relative humidity prevented pollen transport at greater heights (3–100 m) and longer distances (0–1000 m) from the source. This study can contribute to the understanding of how herbicide-resistance weeds or invasive plants affect ecology through wind-mediated pollination and invasion.     

红芽芋球茎片两步法离体快繁及其再生苗生理和光合特性研究

以江西铅山红芽芋(Colocasia esculenta L.Schott var.cormosus‘Hongyayu’)试管苗为材料,建立了芋球茎片两步法离体快繁体系,并对其再生苗的形态指标、染色体数目、生理和光合特性以及叶绿素荧光特性进行了检测。结果表明:(1)红芽芋球茎片单芽诱导的最佳培养基为MS+KT 2 mg/L+6-BA 1 mg/L+NAA0.1mg/L,诱导培养30d后将单芽从球茎片上分离,再接种到生根培养基(MS+KT 2mg/L+NAA 0.1mg/L)上培养30d即可形成完整植株,移栽成活率高达98%;(2)由球茎片单芽、丛生芽、不定芽离体快繁获得的红芽芋再生苗在形态指标、叶下表皮气孔参数、染色体数目、生理生化指标以及叶片光合特性参数和叶绿素荧光特性方面均无显著差异。说明红芽芋球茎片两步法离体培养的再生苗繁殖系数高、染色体数目稳定,该离体快繁体系可应用于江西铅山红芽芋的工厂化生产。     

Identification and characterization of a novel salt‐tolerant esterase from a Tibetan glacier metagenomic library

A salt‐tolerant esterase, designated H9Est, was identified from a metagenomic library of the Karuola glacier. H9Est gene comprised 1071 bp and encoded a polypeptide of 357 amino acids with a molecular mass of 40 kDa. Sequence analysis revealed that H9Est belonged to the family IV of bacterial lypolitic enzyme. H9Est was overexpressed in Escherichia coli and the purified enzyme showed hydrolytic activity towards p‐nitrophenyl esters with carbon chain from 2 to 8. The optimal esterase activity was at 40°C and pH 8.0 and the enzyme retained its activity towards some miscible organic solvents such as polyethylene glycol. A three‐dimensional model of H9Est revealed that S200, D294, and H324 formed the H9Est catalytic triad. Circular Dichroism spectra and molecular dynamic simulation indicated that the esterase had a wide denaturation temperature range and flexible loops that would be beneficial for H9Est performance at low temperatures while retaining heat‐resistant features. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:890–899, 2015     

人TRAF3IP3基因剪接异构体2的克隆表达和生物信息学分析

[目的]克隆、原核表达并纯化人类TRAF3IP3基因剪接异构体2(TRAF3IP3iso2),对TRAF3IP3iso2蛋白进行生物信息学分析。[方法]从人骨髓单个核细胞c DNA中扩增TRAF3IP3iso2开放阅读框区,双酶切连入原核表达载体p ET-28a(+),重组质粒转化E.coli Rosetta(DE3),IPTG诱导表达,SDS-PAGE和Western blot鉴定表达效果,Ni-NTA亲和层析柱纯化目的蛋白;根据测序结果对TRAF3IP3iso2蛋白进行生物信息学分析。[结果]成功克隆了人类TRAF3IP3iso2编码区并构建了原核表达载体p ET-28a(+)-TRAF3IP3iso2,在大肠杆菌中诱导表达、纯化获得了相对分子量约22.7k Da的融合蛋白;生物信息学分析显示TRAF3IP3iso2蛋白二级结构以α螺旋为主,无TRAF3IP3iso1蛋白的跨膜区结构。[结论]证明了人类TRAF3IP3iso2的存在,为TRAF3IP3功能的研究提供了实验依据。     

Distribution patterns of alien invasive plants and their influences on native plants of Hainan Island

 以国家农业部指定的20种恶性入侵植物为目的种, 在海南岛开展其分布特征与入侵强度的调查研究, 重点研究了陆域环境中6种广布入侵植物——飞机草(Chromolaena odorata)、假臭草(Praxelis clematidea)、含羞草(Mimosa pudica)、苏门白酒草(Conyza sumatrensis)、三裂叶蟛蜞菊(Wedelia trilobata)、马缨丹(Lantana camara)在7种生态系统(天然次生林、农田、村落、种植园、林缘、弃耕地、草地)中的入侵频率及入侵植物对本地植物的影响。结果表明: 1)海南岛有恶性入侵植物11种, 占调查目的种总数的55.0%。2)海南岛的东北、西南部分布的入侵植物种数较多, 东南部次之, 中部地区最少。3) 6种入侵植物的整体入侵强度为: 假臭草>飞机草>含羞草>三裂叶蟛蜞菊>马缨丹>苏门白酒草; 苏门白酒草、马缨丹在不同生态系统中的入侵频率无显著差异; 而假臭草在种植园及弃耕地, 含羞草在农田, 三裂叶蟛蜞菊在种植园生态系统中的入侵频率均显著高于其他生境。4)种植园、弃耕地和农田生态系统是植物入侵的主要生境类型, 而林缘和天然次生林生态系统均对植物入侵表现出抵御作用。5)植物入侵对当地植物多样性的影响存在正、负及无关联效应, 并主要影响群落中的草本植物功能群; 样地中入侵植物盖度总值与本地植物平均种数在种植园、农田和村落生态系统中无相关性, 在林缘和弃耕地生态系统中, 两者呈显著负相关关系; 而在草地生态系统中, 在一定盖度范围内, 入侵植物盖度总值与本地植物平均种数呈显著正相关关系。     

异育银鲫GABA A受体γ2亚基全长克隆及生物信息学分析

近年来GABA A受体亚基特异性在药物筛选、研发过程中的应用得到广泛地关注,其中有关α1、β2和γ2三种功能性亚基的研究最为深入。异育银鲫因其良好的生长、繁殖优势,在国内得到广泛养殖。采用RACE法克隆得到了异育银鲫GABA A受体γ2亚基基因全长cDNA,并进行了生物信息学分析。该基因长2 763 bp,其中CDS区长1437 bp,可编码477个氨基酸的前体蛋白。预测蛋白分子量55.3 k D,理论等电点9.13。异育银鲫体内GABA A受体γ2亚基氨基酸序列N端存在1个长度为35个氨基酸的信号肽,4个长度分别为23、20、23和23个氨基酸的跨膜区,3个N-糖基结合位点和2个O-糖基化位点,1个特异性结构域,其氨基酸序列具有明显的氯离子门控通道家族特征。氨基酸序列与其他物种氨基酸序列的同源性都在89%以上,表明该蛋白属于GABA A受体亚基家族。系统进化树表明异育银鲫与斑马鱼聚为一支,亲缘关系最近。