Effect of Vitamin E and Omega-3 Fatty Acids on Protecting Ambient PM2.5-Induced Inflammatory Response and Oxidative Stress in Vascular Endothelial Cells

Although the mechanisms linking cardiopulmonary diseases to ambient fine particles (PM_2.5) are still unclear, inflammation and oxidative stress play important roles in PM_2.5-induced injury. It is well known that inflammation and oxidative stress could be restricted by vitamin E (Ve) or omega-3 fatty acids (Ω-3 FA) consumption. This study investigated the effects of Ve and Ω-3 FA on PM_2.5-induced inflammation and oxidative stress in vascular endothelial cells. The underlying mechanisms linking PM_2.5 to vascular endothelial injury were also explored. Human umbilical vein endothelial cells (HUVECs) were treated with 50 μg/mL PM_2.5 in the presence or absence of different concentrations of Ve and Ω-3 FA. The inflammatory cytokines and oxidative stress markers were determined. The results showed that Ve induced a significant decrease in PM_2.5-induced inflammation and oxidative stress. Malondialdehyde (MDA) in supernatant and reactive oxygen species (ROS) in cytoplasm decreased by Ve, while the superoxide dismutase (SOD) activity elevated. The inflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) also reduced by Ve. Moreover, Ω-3 FA played the same role on decreasing the inflammation and oxidative stress. IL-6 and TNF-α expressions were significantly lower in combined Ve with Ω-3 FA than treatment with Ve or Ω-3 FA alone. The Ve and Ω-3 FA intervention might abolish the PM_2.5-induced oxidative stress and inflammation in vascular endothelial cells. There might be an additive effect of these two nutrients in mediating the PM_2.5-induced injury in vascular endothelial cells. The results suggested that inflammation and oxidative stress might be parts of the mechanisms linking PM_2.5 to vascular endothelial injury.     

Molecular Characterisation and Diagnosis of Root-Knot Nematodes (Meloidogyne spp.) from Turfgrasses in North Carolina,USA

Root-knot nematodes (Meloidogyne spp.) are the most common and destructive plant-parasitic nematode group worldwide and adversely influence both crop quality and yield. In this study, a total of 51 root-knot nematode populations from turfgrasses were tested, of which 44 were from North Carolina, 6 from South Carolina and 1 from Virginia. Molecular characterisation was performed on these samples by DNA sequencing on the ribosomal DNA 18S, ITS and 28S D2/D3. Species-specific primers were developed to identify turfgrass root-knot nematode through simplex or duplex PCR. Four species were identified, including M. marylandi Jepson & Golden in Jepson, 1987, M. graminis (Sledge & Golden, 1964) Whitehead, 1968, M. incognita (Kofoid & White, 1919) Chitwood, 1949 and M. naasi Franklin, 1965 through a combined analysis of DNA sequencing and PCR by species-specific primers. M. marylandi has been reported from North Carolina and South Carolina for the first time. Molecular diagnosis using PCR by species-specific primers provides a rapid and cheap species identification approach for turfgrass root-knot nematodes.     

Forces and Straw Cutting Performance of Double Disc Furrow Opener in No-Till Paddy Soil

Conservation tillage is an energy efficient and low cost tillage system to improve soil environment compared with conventional tillage systems. However, the rice residue management becomes an “impossible to achieve” task due to high soil moisture content at harvest time and the thickness of rice straw. Disc type furrow openers are used for both seed drilling as well as straw cutting during no tillage sowing. A study was conducted to evaluate the draft requirement and straw cutting performances of different sized furrow openers in no-till paddy soil conditions. Double disc furrow opener was tested on an in-field traction bench for three working depths, i.e. 30, 60 and 90 mm, and three forwarding speeds, i.e. 0.1, 0.2 and 0.3 m/s. The draft and vertical forces on the disc were recorded with load cells. These sensors were connected to a data acquisition system developed with hardware and software. The results revealed that the size of the furrow opener, operating depth and the forwarding speed had significant effects (P<0.05) on the horizontal and vertical forces, and the straw cutting performance. Mean values of the draft were 648.9, 737.2 and 784.6 N for the opener with diameters of 330, 450 and 600 mm respectively, and the vertical forces for similar openers were 904.7, 1553.9 and 1620.4 N, respectively. Furthermore, the mean straw cutting efficiencies for the double disc opener with diameters of 330, 450 and 600 mm were 39.36, 78.47 and 65.46%, respectively. The opener with 450 mm diameter provided higher straw cutting efficiency as compared to 600 mm diameter disc, while lowest straw cutting efficiency was observed with 330 mm diameter disc. The 450 mm diameter opener provided the highest straw cutting efficiency (88.6%) at 90 mm working depth and expressed optimum performance compared with other furrow openers.     

深圳市南山区健康人群百日咳抗体水平及疫苗免疫成功率监测

目的了解深圳市南山区健康人群百日咳免疫现状及疫苗免疫成功率。方法健康人群抗体水平监测按照<1岁、1岁~、2岁~、3岁~、4岁~、5岁~、10岁~、15岁~、≥20岁共9个年龄组,每个年龄组随机抽取50~60人共508人进行观察,采用ELISA检测其百日咳抗体水平,免疫成功率监测选定监测对象为50人,同一对象于基础免疫前和完成基础免疫后1个月进行抗体水平检测。结果健康人群百日咳抗体阳性率为44.3%,抗体几何平均浓度(GMC)为21.69 U/m L。免疫成功率的免疫前抗体检测结果为:阴性94.0%、临界4.0%、阳性2.0%,抗体GMC为3.39 U/m L;免疫后抗体检测结果:阴性38.0%、临界16.0%、阳性46.0%,抗体GMC为20.75 U/m L。结论深圳市南山区健康人群百日咳抗体阳性率和免疫成功率均不高,提示要提高百日咳疫苗的免疫成功率和接种率,必要时进行加强免疫。     

大肠埃希菌外膜蛋白OmpC的原核表达与免疫保护作用研究

Omp C蛋白为大肠埃希菌主要外膜蛋白,具有提高宿主免疫能力的作用,在疫苗上有很好的应用前景。通过分子克隆获得Omp C蛋白的表达菌株;Western-blotting法证实Omp C抗体可与表达的重组蛋白很好的结合。利用切胶纯化获得Omp C蛋白,免疫小鼠产生抗体,然后攻毒大肠埃希菌肠道致病菌,结果显示保护率达到63.64%,与对照相比较具有显著差异。利用正交试验,获得Omp C菌株的最佳表达条件为:诱导时菌液OD600值0.5,IPTG终浓度0.3 mmol/L,诱导时间8 h,温度32℃;最佳培养条件为:葡萄糖浓度0%,转速230 r/min,装液量50 m L。为Omp C工业发酵、蛋白功能与疫苗开发研究奠定了基础。     

GADD45A inhibits autophagy by regulating the interaction between BECN1 and PIK3C3

GADD45A is a TP53-regulated and DNA damage-inducible tumor suppressor protein, which regulates cell cycle arrest, apoptosis, and DNA repair, and inhibits tumor growth and angiogenesis. However, the function of GADD45A in autophagy remains unknown. In this report, we demonstrate that GADD45A plays an important role in regulating the process of autophagy. GADD45A is able to decrease LC3-II expression and numbers of autophagosomes in mouse tissues and different cancer cell lines. Using bafilomycin A₁ treatment, we have observed that GADD45A regulates autophagosome initiation. Likely, GADD45A inhibition of autophagy is through its influence on the interaction between BECN1 and PIK3C3. Immunoprecipitation and GST affinity isolation assays exhibit that GADD45A directly interacts with BECN1, and in turn dissociates the BECN1-PIK3C3 complex. Furthermore, we have mapped the 71 to 81 amino acids of the GADD45A protein that are necessary for the GADD45A interaction with BECN1. Knockdown of BECN1 can abolish autophagy alterations induced by GADD45A. Taken together, these findings provide the novel evidence that GADD45A inhibits autophagy via impairing the BECN1-PIK3C3 complex formation.     

Oxidative Damage and Mitochondrial Injuries Are Induced by Various Irrigation Pressures in Rabbit Models of Mild and Severe Hydronephrosis

Objective

We aimed to study whether tolerance to irrigation pressure could be modified by evaluating the oxidative damage of obstructed kidneys based on rabbit models experiencing different degrees of hydronephrosis.

Methods

A total of 66 rabbits were randomly divided into two experimental groups and a control group. In the experimental groups, the rabbits underwent a surgical procedure inducing mild (group M, n=24) or severe (group S, n=24) hydronephrosis. In each experimental group, the rabbits were then randomly divided into 4 subgroups (M0-M3 and S0-S3) consisting of 6 rabbits each. Group 0 received no perfusion. Groups 1 through 3 were perfused with 20, 60 and 100 mmHg fluid, respectively. For the control group, after a sham operation was performed, the rabbits were divided into 4 subgroups and were perfused with fluid at 0, 20, 60 or 100 mmHg of pressure. Kidney injuries was evaluated by neutrophil gelatinase associated lipocalin (NGAL). Oxidative damage was assessed by analyzing superoxide dismutase (Mn-SOD) activity, malondialdehyde (MDA) levels, glutathione reductase (GR), catalase (CAT) and peroxide (H₂O₂) levels, mitochondrial injuries was assessed by mitochondrial membrane potential (MMP), the mitochondrial ultrastructure and tubular cell apoptosis.

Results

In the experimental groups, all results were similar for groups 0 and 1. In group 2, abnormalities were observed in the S group only, and the kidneys of rabbits in group 3 suffered oxidative damage and mitochondrial injuries with increased NGAL, decreased Mn-SOD, GR and CAT,increased MDA and H₂O₂, lower levels of MMP, mitochondrial vacuolization and an increased apoptotic index.

Conclusion

In rabbits, severely obstructed kidneys were more susceptible to oxidative damage and mitochondrial injury than mildly obstructed kidneys when subjected to higher degrees of kidney perfusion pressure.     

光片荧光显微镜特点及其应用

传统荧光显微镜由于对某些荧光分子存在光毒性、光损伤等方面的缺陷,无法满足对部分活体样本进行长时间观测的需求。光片荧光显微镜（light sheet fluorescence microscope,LSFM）是一种新型荧光显微镜,有别于激光共聚焦显微镜,其特殊的正交光路设计和高效的信号采集装置,使其具备低光毒性、低光漂白、低光损伤和高时空分辨率等优良特性,从而能对细胞及大尺度生物组织样本进行时空连续性较好的记录,尤其适宜于活体生物样品。基于此,概述了光片荧光显微镜的成像原理、成像优势、成像效果的改进与优化历程及其在生命科学领域应用所取得的研究成果,重点对近三年相关应用进行了汇总,并简要介绍了其在神经生物学、发育生物学、动物细胞生物学和植物科学领域中一部分代表性研究内容,最后,总结了光片荧光显微镜的优点与发展至今仍存在的不足,并对其在光遗传学和多组学研究中的潜在应用进行了展望,以期为研究人员提供较为系统的光片荧光显微镜相关基础知识、最新的研究应用进展以及未来的潜在应用方向,为研究人员提供参考。