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201.
Bai L Xia S Lan R Liu L Ye C Wang Y Jin D Cui Z Jing H Xiong Y Bai X Sun H Zhang J Wang L Xu J 《PloS one》2012,7(3):e33054
Citrobacter freundii is an infrequent but established cause of diarrhea in humans. However, little is known of its genetic diversity and potential for virulence. We analyzed 26 isolates, including 12 from human diarrheal patients, 2 from human fecal samples of unknown diarrheal status, and 12 from animals, insects, and other sources. Pulsed field gel electrophoresis using XbaI allowed us to divide the 26 isolates into 20 pulse types, while multi-locus sequence typing using 7 housekeeping genes allowed us to divide the 26 isolates into 6 sequence types (STs) with the majority belonging to 4 STs. We analyzed adhesion and cytotoxicity to HEp-2 cells in these 26 strains. All were found to adhere to HEp-2 cells. One strain, CF74, which had been isolated from a goat, showed the strongest aggregative adhesion pattern. Lactate dehydrogenase (LDH) released from HEp-2 cells was evaluated as a measure of cytotoxicity, averaging 7.46%. Strain CF74 induced the highest level of LDH, 24.3%, and caused >50% cell rounding, detachment, and death. We named strain CF74 "cytotoxic and aggregative C. freundii." Genome sequencing of CF74 revealed that it had acquired 7 genomic islands, including 2 fimbriae islands and a type VI secretion system island, all of which are potential virulence factors. Our results show that aggregative adherence and cytotoxicity play an important role in the pathogenesis of C. freundii. 相似文献
202.
Seidl K Solis NV Bayer AS Hady WA Ellison S Klashman MC Xiong YQ Filler SG 《PloS one》2012,7(6):e39633
Endothelial cells are important in the pathogenesis of bloodstream infections caused by Candida albicans and Staphylococcus aureus. Numerous investigations have used human umbilical vein endothelial cells (HUVECs) to study microbial-endothelial cell interactions in vitro. However, the use of HUVECs requires a constant supply of umbilical cords, and there are significant donor-to-donor variations in these endothelial cells. The use of an immortalized endothelial cell line would obviate such difficulties. One candidate in this regard is HMEC-1, an immortalized human dermal microvascular endothelial cell line. To determine if HMEC-1 cells are suitable for studying the interactions of C. albicans and S. aureus with endothelial cells in vitro, we compared the interactions of these organisms with HMEC-1 cells and HUVECs. We found that wild-type C. albicans had significantly reduced adherence to and invasion of HMEC-1 cells as compared to HUVECs. Although wild-type S. aureus adhered to and invaded HMEC-1 cells similarly to HUVECs, an agr mutant strain had significantly reduced invasion of HMEC-1 cells, but not HUVECs. Furthermore, HMEC-1 cells were less susceptible to damage induced by C. albicans, but more susceptible to damage caused by S. aureus. In addition, HMEC-1 cells secreted very little IL-8 in response to infection with either organism, whereas infection of HUVECs induced substantial IL-8 secretion. This weak IL-8 response was likely due to the anatomic site from which HMEC-1 cells were obtained because infection of primary human dermal microvascular endothelial cells with C. albicans and S. aureus also induced little increase in IL-8 production above basal levels. Thus, C. albicans and S. aureus interact with HMEC-1 cells in a substantially different manner than with HUVECs, and data obtained with one type of endothelial cell cannot necessarily be extrapolated to other types. 相似文献
203.
Yin Hu Wei Chen Tianyu Lei Bin Zhou Yu Jiao Yichao Yan Xinchuan Du Jianwen Huang Chunyang Wu Xuepeng Wang Yang Wang Bo Chen Jun Xu Chao Wang Jie Xiong 《Liver Transplantation》2019,9(7)
Significant progress has achieved for developing lithium–sulfur (Li–S) batteries with high specific capacities and excellent cyclic stability. However, some critical issues emerge when attempts are made to raise the areal sulfur loading and increase the operation current density to meet the standards for various industrial applications. In this work, polyethylenimine‐functionalized carbon dots (PEI‐CDots) are designed and prepared for enhancing performance of the Li–S batteries with high sulfur loadings and operation under high current density situations. Strong chemical binding effects towards polysulfides and fast ion transport property are achieved in the PEI‐CDots‐modified cathodes. At a high current density of 8 mA cm?2, the PEI‐CDots‐modified Li–S battery delivers a reversible areal capacity of 3.3 mAh cm?2 with only 0.07% capacity decay per cycle over 400 cycles at 6.6 mg sulfur loading. Detailed analysis, involving electrochemical impedance spectroscopy, cyclic voltammetry, and density functional theory calculations, is done for the elucidation of the underlying enhancement mechanism by the PEI‐CDots. The strongly localized sulfur species and the promoted Li+ ion conductivity at the cathode–electrolyte interface are revealed to enable high‐performance Li–S batteries with high sulfur loading and large operational current. 相似文献
204.
Genetic mapping of the rice ionome in leaves and grain: identification of QTLs for 17 elements including arsenic, cadmium, iron and selenium 总被引:1,自引:0,他引:1
Gareth J. Norton Claire M. Deacon Lizhong Xiong Shaoying Huang Andrew A. Meharg Adam H. Price 《Plant and Soil》2010,329(1-2):139-153
Research into the composition of cereal grains is motivated by increased interest in food quality. Here multi-element analysis is conducted on leaves and grain of the Bala x Azucena rice mapping population grown in the field. Quantitative trait loci (QTLs) for the concentration of 17 elements were detected, revealing 36 QTLs for leaves and 41 for grains. Epistasis was detected for most elements. There was very little correlation between leaf and grain element concentrations. For selenium, lead, phosphorus and magnesium QTLs were detected in the same location for both tissues. In general, there were no major QTL clusters, suggesting separate regulation of each element. QTLs for grain iron, zinc, molybdenum and selenium are potential targets for marker assisted selection to improve seed nutritional quality. An epistatic interaction for grain arsenic also looks promising to decrease the concentration of this carcinogenic element. 相似文献
205.
Lisong Shi Cong Li Chuchu Wang Yunlong Xia Gang Wu Fan Wang Chengqi Xu Pengyun Wang Xiuchun Li Dan Wang Xin Xiong Ying Bai Mugen Liu Jingyu Liu Xiang Ren Lianjun Gao Binbin Wang Qiutang Zeng Bo Yang Xu Ma Yanzong Yang Xin Tu Qing Kenneth Wang 《Human genetics》2009,126(6):843-849
Atrial fibrillation (AF) is the most common arrhythmia in the clinical setting and an independent risk factor for stroke. Approximately 10 million Chinese people are affected by AF, but the genetic basis is largely unknown. A recent genome-wide association study in Iceland identified association between SNP rs2200733 on 4q25 and AF; however, many independent replication studies are essential to unequivocally validate this association. To assess the association between rs2200733 and AF as well as that between rs2200733 and ischemic stroke in a mainland Chinese Han population, we carried out case–control association studies with 383 AF patients versus 851 non-AF controls and 811 ischemic stroke patients versus 688 non-stroke controls. Highly significant association was detected between rs2200733 and AF in a Chinese Han population (allelic P = 3.7 × 10?11 with OR = 1.81; genotypic P = 4.1 × 10?12 with a dominant model). When the AF cases were divided into lone AF (32.6%) and other types of AF (67.4%), significantly stronger association was found with lone AF (OR = 2.40, P = 1.3 × 10?9 compared to OR = 1.59, P = 6.2 × 10?7 for other types of AF; P = 0.02 for two ORs). No significant association was found between rs2200733 and ischemic stroke. Our results suggest that SNP rs2200733 confers a highly significant risk of AF, but not ischemic stroke, in a more representative Chinese Han population in the mainland China. 相似文献
206.
Abberent expression of NOR1 protein in tumor associated macrophages contributes to the development of DEN‐induced hepatocellular carcinoma 下载免费PDF全文
207.
目的:在大鼠血管钙化模型上,观察外源性补充硫酸镁对大鼠血管钙化的影响,以探讨硫酸镁在血管钙化中作用及机制。方法:用维生素D3加尼古丁诱导大鼠血管钙化,von Kossa染色、钙含量测定及碱性磷酸酶活性测定判断血管钙化程度;用半定量RT-PCR方法测定血管钙化标志分子骨桥蛋白mRNA水平;用生物化学方法测定血管一氧化氮(NO)、超氧化物歧化酶(SOD)和丙二醛(MDA)含量。结果:钙化组大鼠血压升高,收缩压较对照组高27%(P<0.05);血管von Kossa染色见血管中膜弹性纤维间可见大量棕黑色颗粒沉积,主动脉钙含量及碱性磷酸酶活性分别较对照高3.9倍和3.4倍(P<0.01),钙化血管组织骨桥蛋白mRNA表达上调40%(P<0.01),血管钙化后可加重血管组织过氧化损伤;而诱导钙化后外源性补充硫酸镁可减轻血管钙化程度,与钙化组比较,低、高剂量硫酸镁组均明显缓解上述指标的变化。结论:诱导血管钙化后外源性补充硫酸镁可以减轻大鼠血管钙化和血管损伤程度。 相似文献
208.
甲醛对大鼠脑影响的实验形态学研究 总被引:5,自引:1,他引:5
24只Wistar大鼠,体重200~280g。6只为正常对照组,18只为实验性甲醛蒸气吸入组,每天定时吸入甲醛蒸气(200mg/m3)30分钟,分别在7、14和21天后处死,然后观察大脑皮层神经细胞的酶组织化学变化及超微结构变化。酶组织化学结果显示:SDH、Mg-MTase,ChE活性降低↓;ALP、ACP、MAO活性增强↑。超微结构变化可见(21天):皮层神经细胞线粒体嵴断裂、肿胀、空泡样变。表明甲醛对大脑皮层神经细胞的功能和结构均有影响。 相似文献
209.
The number of Beijing's civil vehicles is growing rapidly due to the great support of the automobile industry and the Chinese government and the increasing average per capita income of China's people. Exhaust emissions from vehicles have already become the main source of Beijing's air pollution. Based on the Long-range Energy Alternatives Planning System (LEAP), this article predicts the energy consumption and exhaust emissions from Beijing's civil vehicles. Also, we estimated the reduction potentials of China's new fuel consumption standards and exhaust pollutants standards that will be implemented from 2008 to 2020. Two scenarios were developed: “Business as Usual” (BAU) and “New Standard” (NS). In the BAU scenario, the Chinese government would do nothing to improve the fuel consumption standards and exhaust pollutants standards in the future. In the NS scenario, the Chinese government would implement more strict fuel consumption standards and exhaust pollutants standards for Beijing's civil vehicles. By comparing the results of the two scenarios for year 2020, the energy consumption will experience a reduction of 7.8%, and the exhaust pollutants CO, HC, NOX, PM, and the emissions of CO2 would decrease by 43.3%, 36.4%, 60.3%, 81.2%, and 7.8%, respectively. 相似文献
210.
Xiao-Xing Xiong Li-Juan Gu Jian Shen Xian-Hui Kang Yue-Ying Zheng Si-biao Yue Sheng-Mei Zhu 《Neurochemical research》2014,39(1):216-224
Stroke results in inflammation, brain edema, and neuronal death. However, effective neuroprotectants are not available. Recent studies have shown that high mobility group box-1 (HMGB1), a proinflammatory cytokine, contributes to ischemic brain injury. Aquaporin 4 (AQP4), a water channel protein, is considered to play a pivotal role in ischemia-induced brain edema. More recently, studies have shown that pannexin 1 channels are involved in cerebral ischemic injury and the cellular inflammatory response. Here, we examined whether the pannexin 1 channel inhibitor probenecid could reduce focal ischemic brain injury by inhibiting cerebral inflammation and edema. Transient focal ischemia was induced in C57BL/6J mice by middle cerebral artery occlusion (MCAO) for 1 h. Infarct volume, neurological score and cerebral water content were evaluated 48 h after MCAO. Immunostaining, western blot analysis and ELISA were used to assess the effects of probenecid on the cellular inflammatory response, HMGB1 release and AQP4 expression. Administration of probenecid reduced infarct size, decreased cerebral water content, inhibited neuronal death, and reduced inflammation in the brain 48 h after stroke. In addition, HMGB1 release from neurons was significantly diminished and serum HMGB1 levels were substantially reduced following probenecid treatment. Moreover, AQP4 protein expression was downregulated in the cortical penumbra following post-stroke treatment with probenecid. These results suggest that probenecid, a powerful pannexin 1 channel inhibitor, protects against ischemic brain injury by inhibiting cerebral inflammation and edema. 相似文献