Inhibitory effects of silver nanoparticles on H1N1 influenza A virus in vitro

Silver nanoparticles have demonstrated efficient inhibitory activities against human immunodeficiency virus (HIV) and hepatitis B virus (HBV). However, the effects of silver nanoparticles against H1N1 influenza A virus remain unexplored. In this study, the interaction of silver nanoparticles with H1N1 influenza A virus was investigated. Silver nanoparticles with mean particle diameters of 10nm were prepared for the hemagglutination inhibition test, the embryo inoculation assay, and the Mosmann-based 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, where these tests were used to determine the inhibitory activity of silver nanoparticles on H1N1 influenza A virus. MDCK cells were used as the infection model. Electron microscopy analysis and flow cytometry assay were used to determine whether silver nanoparticles could reduce H1N1 influenza A virus-induced apoptosis in MDCK cells. This study demonstrates that silver nanoparticles have anti-H1N1 influenza A virus activities. The inhibitory effects of silver nanoparticles on influenza A virus may be a novel clinical strategy for the prevention of influenza virus infection during the early dissemination stage of the virus.     

难治性中耳真菌感染的诊治分析

目的探讨难治性中耳真菌感染的临床特征及治疗方法。方法回顾分析2005年2月～2009年2月难治性中耳真菌感染62例患者（62耳）的临床特征、菌群分布,并将患者随机分为口服伊曲康唑胶囊组（31耳）和涂用硝酸咪康唑乳膏组（31耳）进行疗效对比。结果真菌培养阳性34株,阳性率54.8%（34/62）。真菌培养多为曲霉菌24/34（70.6%）。治疗2周后,涂用硝酸咪康唑乳膏组痊愈21耳,显效2耳,无效8耳,总有效率为74.2%;口服伊曲康唑胶囊组痊愈29例,显效1例,无效1例,总有效率为96.8%。结论难治性中耳炎合并中耳真菌感染属深部真菌感染,主要致病真菌是曲霉菌,口服伊曲康唑胶囊组疗效明显优于涂用硝酸咪康唑乳膏组。     

X线电离辐射诱导人鼻咽癌CNE-2细胞发生上皮-间充质转化及其潜在机制

目的:探讨X线电离辐射诱导鼻咽癌CNE-2细胞发生上皮-间充质转化(epithelial-mesenchymal transition,EMT)及其可能的信号通路。方法:分别采用0 Gy、2 Gy、4 Gy和8 Gy的X线照射鼻咽癌CNE-2细胞,通过倒置显微镜观察照射24 h后细胞形态的改变;应用细胞划痕实验和Transwell实验观察细胞迁移和侵袭能力的变化;分别采用real-time PCR和Western blot法检测EMT相关蛋白E-钙黏蛋白(E-cadherin)、N-钙黏蛋白(N-cadherin)和波形蛋白(vimentin)mRNA及蛋白水平的变化,并采用Western blot法检测Akt和p-Akt蛋白水平的变化。结果:经X线照射后鼻咽癌CNE-2细胞呈典型的"鹅卵石"样或纺锤形,且伸出伪足,细胞间隙增大,细胞的侵袭和迁移能力增强(P0.01);real-time PCR和Western blot法检测结果显示,与未照射组相比,各照射组细胞中E-cadherin mRNA和蛋白的表达水平均显著下调(P0.01),而N-cadherin和vimentin mRNA和蛋白的表达水平明显上调(P0.05);PI3K/Akt信号通路中p-Akt蛋白的水平显著升高(P0.01),而Akt的表达无明显变化。结论:X线电离辐射能够诱导鼻咽癌CNE-2细胞发生EMT,其机制可能与PI3K/Akt信号通路的激活有关。     

基于BP神经网络的手势动作表面肌电信号的模式识别

手势语言在日常生活中有着广泛的应用,本研究利用手势动作时从前臂4块肌肉上获取的4路表面肌电（SEMG）信号,经特征提取并采用BP神经网络,对8种手势动作模式进行了识别。鉴于BP网络具有较强的模式分类能力,而特征提取（幅度绝对值均值、AR模型系数、过零率）又利用了多路肌电信号的信息,实验结果取得了较高的识别正确率,表明所采用的方法是有效的。     

In vivo evolution of the gp90 gene and consistently low plasma viral load during transient immune suppression demonstrate the safety of an attenuated equine infectious anemia virus (EIAV) vaccine

To study the in vivo evolution of the attenuated Chinese equine infectious anemia virus (EIAV) vaccine, viral gp90 gene variation and virus replication in immunosuppressed hosts were investigated. The results showed that after vaccination, the gp90 gene followed an evolutionary trend of declining diversity. The trend coincided with the maturation of immunity to EIAV, and eventually, the gp90 gene became highly homologous. The sequences of these predominant quasispecies were consistently detected up to 18 months after vaccination. Furthermore, after transient immune suppression with dexamethasone, the plasma viral RNA copy number of the vaccine strain in three vaccinated ponies remained consistently below the “pathogenic threshold” level, while the viral load increased by 25,000-fold in the positive control of an inapparent carrier of the parental virulent strain. This study is the first to provide evidence for the safety of an attenuated lentiviral vaccine with decreased genomic diversity and consistently low viral replication under suppressed immunity.     

江门市新会区华支睾吸虫病流行现状调查与分析

目的了解江门市新会区华支睾吸虫病的流行现状,确定华支睾吸虫病的高危人群,提供当地华支睾吸虫病感染因素的线索。方法采用免疫酶联吸附法检测血清中华支睾吸虫特异性抗体;采用改良加藤氏法检测粪便虫卵;采用消化法检测淡水鱼中华支睾吸虫囊蚴;进行问卷调查华支睾吸虫感染相关的生活和行为方式;同时采用病例对照方法分析影响华支睾吸虫感染的相关流行因素。结果共调查1720人,华支睾吸虫平均感染率为18.14%,男性感染率高于女性（P〈0.001）。各年龄组均有感染,感染率差异有统计学意义（P〈0.001）。共调查常见淡水鱼6种共273尾,6种淡水鱼体内均查到华支睾吸虫囊蚴。病例对照研究显示,吃半熟鱼习惯及外出饮食等行为是最重要的危险因子。结论新会区华支睾吸虫病流行范围广,感染率高,已经成为一个严重的公共卫生问题,应积极开展综合性防控工作。     

Progressive CD127 down‐regulation correlates with increased apoptosis of CD8 T cells during chronic HIV‐1 infection

Chronic HIV‐1 infection can induce a significant decrease in CD127 expression on CD8 T cells, but the underlying mechanisms and immunological consequences are unclear. In this study, we investigated CD127 expression on CD8 T cells from a total of 51 HIV‐1‐infected subjects and 16 healthy individuals and analyzed the association between CD127 expression and CD8 T‐cell apoptosis in these HIV‐1‐infected subjects. We found that CD127 expression on total CD8 T cells was significantly down‐regulated, which was correlated with the increased CD8 T‐cell apoptosis and disease progression of chronic HIV‐1 infection. The in vitro addition of IL‐7 efficiently rescued the spontaneous apoptosis of CD8 T cells from HIV‐1‐infected individuals. IL‐7 stimulation also transiently down‐regulated CD127 expression, whereas some of the CD127^? CD8 T cells regained CD127 expression soon after IL‐7 was retracted from the incubation medium. Thus, IL‐7 stimulation reduced apoptosis of both CD127⁺ and CD127^?CD8 T cells to some degree. These data indicate that CD127 loss might impair IL‐7 signaling and increase CD8 T‐cell apoptosis during HIV‐1 infection. This study, therefore, will extend the notion that IL‐7 could be a good candidate for immunotherapy in HIV‐1‐infected patients.     

Polygalasaponin G promotes neurite outgrowth of cultured neuron on myelin

Myelin contains many axonal outgrowth inhibitory components which contribute to regeneration failure after neuronal injury in the mammalian central nervous system (CNS). In an attempt to develop small molecular agents to promote axonal outgrowth, we screened a compound library purified from traditional Chinese herbs, and found a small molecular compound polygalasaponin G (PS-G), extracted from Polygala japonica, which has a potent neurotrophic activity on PC12 cells and cultured cortical neurons. We reported, to our knowledge for the first time, that PS-G could promote neurite outgrowth of neurons cultured on the myelin substrates and inhibit the activation of RhoA. Thus, our results could represent a therapeutic approach to improve axon regeneration after CNS injuries.     

Evaluation of human mesenchymal stem cells response to biomimetic bioglass-collagen-hyaluronic acid-phosphatidylserine composite scaffolds for bone tissue engineering

The aim of this study was to examine in vitro the response of human mesenchymal stem cells (hMSCs) on the novel biomimetic bioglass-collagen-hyaluronic acid-phosphatidylserine (BG-COL-HYA-PS) composite scaffold for potential use in bone tissue engineering. The initial attachment, the proliferation, migration and differentiation behavior of the cells on the BG-COL-HYA-PS composites were assessed in comparison with those on pure 58sBG, BG-COL, and BG-COL-HYA composites in either growth medium (L-DMEM supplemented with 10% fetal bovine serum) or osteogenic medium (growth medium supplemented with 0.1 microM dexamethasone, 10 mM beta-glycerophosphate, and 50 microM ascorbic acid). HMSCs attached, and subsequently proliferated and migrated on the BG-COL-HYA-PS composites to a significantly higher degree. The alkaline phosphatase (ALP) staining, ALP activity and the expression of the bone associated gene ALP, osteocalcin (OC), and osteopontin (OPN) was also significantly higher in the hMSCs on the BG-COL-HYA-PS scaffolds than those on the BG-COL, BG-COL-HYA composites and the pure 58sBG. These findings suggest that the BG-COL-HYA-PS composite porous scaffolds have high potential for use as scaffolds in bone tissue engineering and repair.     

Effects of Intracerebroventricular Injection of Iron Dextran on the Iron Concentration and Divalent Metal Transporter 1 Expression in the Caudate Putamen and Substantia Nigra of Rats

The cellular localization of DMT1 and its functional characterization suggest that DMT1 may play an important role in the physiological brain iron transport. But the regulation of DMT1 expression by iron in the brain is still not clearly understood. In this study, both the contents of ferric and ferrous iron as well as DMT1 expression were evaluated in CPu and SN after ICV of 500 μg iron dextran/rat/day for 3 or 7 days. It was found that the iron levels in CPu and SN were not altered obviously until ICV for 7 days. Immunohistochemistry results indicated that the expression of DMT1 (?IRE) in CPu and SN was not altered significantly after 3 days of ICV. Whereas the expression of DMT1 (?IRE) decreased significantly after 7 days of ICV when ferrous iron was increased significantly. Contrary to that of DMT1 (?IRE) in the same regions, there were no significant alterations in DMT1 (+IRE) expression in CPu and SN in spite of the existence of the altered iron levels, compared with that of control groups. The results demonstrate that DMT1 (?IRE) expression was correlated probably with brain iron levels; especially, its regulation was correlated with ferrous iron (not ferric iron) in CPu and SN in adult rats, compared with those of saline‐injected control rats. The effect of ferrous iron on the expression of DMT1 (?IRE) in the brain also suggests that it might play a major physiological role in brain iron uptake and transport, but further studies are needed to clarify these issues. Anat Rec, 2009. © 2008 Wiley‐Liss, Inc.