Cellular characterization of actin gene concerned with contact‐dependent mechanisms in Naegleria fowleri

Free‐living amoeba, Naegleria fowleri, destroys target cells through contact‐dependent mechanisms, such as phagocytosis and/or trogocytosis. A previous experiment showed that the nf‐actin gene consisted of 1.2 kbp, produced a 50.1 kDa recombinant protein (Nf‐actin), and was localized on the cytoskeleton, pseudopodia and amoebastome. In this study, cellular characterization of the nf‐actin gene concerned with contact‐dependent mechanisms in N fowleri was performed. The nf‐actin gene was amplified from a gene‐cloned vector, pEXQP5‐T7/NT TOPO. The nf‐actin gene was introduced into the Ubi‐pEGFP‐C2 vector, and Ubi‐pEGFP‐C2/nf‐actin was transfected into N fowleri trophozoites. Strong GFP fluorescence was detected in N fowleri trophozoites transfected with Ubi‐pEGFP‐C2/nf‐actin. Expression of EGFP‐Nf‐actin protein was detected by Western blot analysis. The nf‐actin‐overexpressing N fowleri showed significantly increased adhesion activity against extracellular matrix components, fibronectin, collagen I and fibrinogen, compared with wild‐type N fowleri. Moreover, nf‐actin‐overexpressing N fowleri showed increased phagocytic activity and cytotoxicity in comparison with wild‐type N fowleri. In summary, the overexpressed nf‐actin gene has an important function in ability to increase cell adhesion, cytotoxicity and phagocytosis by N fowleri.     

Effect of Intra‐wound Vancomycin for Spinal Surgery: A Systematic Review and Meta‐analysis

Intra‐site prophylactic vancomycin in spine surgery is an effective method of decreasing the incidence of postsurgical wound infection. However, there are differences in the prophylactic programs used for various spinal surgeries. Thus, this systematic review and meta‐analysis aimed to evaluate the effectiveness of using intra‐wound vancomycin during spinal surgery and to explore the effects of dose‐dependence and the method of administration in a subgroup analysis. A total of 628 citations or studies were searched in PubMed, Ovid, Web of Science, and Google Scholar that were published before August 2016 with the terms “local vancomycin”, “intra‐wound vancomycin”, “intraoperative vancomycin”, “intra‐site vancomycin”, “topical vancomycin”, “spine surgery”, and “spinal surgery”. Finally, 19 retrospective cohort studies and one prospective case study were eligible for inclusion in the systematic review and meta‐analysis. The odds of developing postsurgical wound infection without prophylactic local vancomycin use were 2.83‐fold higher than the odds of experiencing wound infection with the use of intra‐wound vancomycin (95% confidence interval, 2.03–3.95; P = 0.083; I² = 32.2%). The subgroup analysis including the dosage and the method of administration, revealed different results compared to previous research. The value of I² in the 1‐g group was 27.2%, which was much lower than in the 2‐g group (I² = 57.6%). At the same time, the value of I² was 0.0% (P = 0.792, OR = 2.70) when vancomycin powder was directly sprinkled into all layers of the wound. However, there is high heterogenicity (I² = 60.0%, P = 0.007, OR = 2.83) when vancomycin powder is not exposed to the bone graft and instrumentation. There are differences found with the method of local application of vancomycin for reducing postoperative wounds and further studies are necessary, including investigations focusing on the dose‐dependent effects during spinal or the topical pharmacokinetic and other orthopaedic surgeries.     

人预存天然抗体与猪胰腺细胞的异种反应性研究

目的 分析人预存天然抗体与猪各种胰腺细胞的异种反应性及其同种型。方法 将患者和正常人血清预先加热灭活并按1：2、1：4、1：8、1：16、1：32倍比稀释,分别同猪胰腺冰冻切片于37℃下孵育30min,冲洗后组织进一步用免疫荧光标记的羊抗人IgG和IgG抗体于37℃下孵育30min。采用间接免疫荧光染色法检测人预存天然抗体与猪胰腺细胞的反应性。结果 55．6％的患者和55．0％的正常人体内均存在着抗猪内分泌细胞的天然抗体,但患者血清中强阳性的百分率更高。100％的患者和95．0％的对照血清都可同一种或多种胰腺细胞反应。预存天然抗体的同种型包括IgG和IgM两种。结论 鉴于预存抗体同猪胰腺细胞的强阳性反应,移植前行配型试验和移植物预处理对移植的胰岛素细胞的存活是必要的。     

An international matched cohort study of the contribution of metabolic impairments to subclinical atherosclerosis in United Kingdom and Jamaican African-Caribbeans

Caucasian carriers of the T allele at R46L in the proprotein convertase subtilisin/kexin type 9 (PCSK9) locus have been reported to have 15% lower low-density lipoprotein (LDL) cholesterol (C) levels and 47% lower coronary heart disease (CHD) risk. Our objective was to examine two PCSK9 single nucleotide polymorphisms (SNPs), R46L and E670G, in 5783 elderly participants in Prospective Study of Pravastatin in the Elderly at Risk (PROSPER), of whom 43% had a history of vascular disease at baseline, and who were randomized to pravastatin or placebo with followup. In this population 3.5% were carriers of the T allele at R46L, and these subjects had significantly (p < 0.001) lower levels of LDL C (mean, −10%), no difference in LDL C lowering response to pravastatin, and a non-significant 19% unadjusted and 9% adjusted decreased risk of vascular disease at baseline, with no on trial effect. Moreover, 6.0% were carriers of the G allele at E670G with no significant relationships with baseline LDL C, response to pravastatin, or vascular disease risk being observed. Our data support the concept that the rare allele of the R46L SNP at the PCSK9 locus significantly lowers LDL C, but does not greatly reduce CHD risk in an elderly population with a high prevalence of cardiovascular disease.     

星点设计-效应面法优化pH值依赖型岩黄连碱口服结肠靶向纳米粒

目的 采用星点设计-效应面法（central composite design-response surface methodology,CCD-RSM）优化pH值依赖型岩黄连碱口服结肠靶向纳米粒（dehydrocavidine-chitosan/pectin-nanoparticles,DC-CS/PT-NPs）制备工艺,并对其进行质量表征及体外释放行为评价。方法 采用离子凝胶法制备DC-CS/PT-NPs,以粒径、PDI、ζ电位、包封率、载药量作为评价指标,采用单因素考察和CCD-RSM优化DC-CS/PT-NPs制备工艺。通过透射电子显微镜（transmission electron microscope,TEM）、扫描电子显微镜（scanning electron microscope,SEM）、傅里叶红外光谱（Fourier transform infrared spectroscopy,FT-IR）、差示扫描量热法（differential scanning calorimetry,DSC）和X射线衍射法（X-ray diffraction,XRD）对DC-CS/PT-NPs进行表征,并进行体外释放性能评价。结果 最佳处方为壳聚糖质量浓度为1.5 mg/mL,果胶质量浓度为1.5 mg/mL,TPP质量浓度为2.0 mg/mL,壳聚糖pH值为5.0。DC-CS/PT-NPs包封率为（61.64±1.77）%,载药量为（8.05±0.18）%,粒径为（418.65±4.92）nm,ζ电位为（−14.14±0.22）mV。DC-CS/PT-NPs呈均匀的球形或类球形;制备成纳米粒后,药物的晶型发生了改变;体外释药结果表明,DC-CS/PT-NPs在人工胃液中2 h仅释放24.35%,在人工小肠液中4 h累积释放率＜40%,在人工结肠液中10 h累积释放率＞85%。结论 CCD-RSM所建立的模型可用于DC-CS/PT-NPs处方优化,DC-CS/PT- NPs具有良好的体外结肠释药特征。     

LED红光联合重组人表皮生长因子治疗面部激素依赖性皮炎的疗效观察

目的 探讨LED红光联合重组人表皮生长因子治疗面部激素依赖性皮炎的疗效.方法 收集40例面部激素依赖性皮炎患者,随机将患者分为联合治疗组和对照组各20例.联合治疗组患者给予LED红光照射治疗,20分/次,2次/周.每次照射后给予重组人表皮生长因子外用溶液湿敷20分钟.对照组仅单独给予LED红光照射治疗,20分/次,2次...     

Identification of synaptic activity-dependent genes by exposure of cultured cortical neurons to tetrodotoxin followed by its withdrawal

Activity-dependent gene expression is one of the key mechanisms of synaptic plasticity that form the basis of higher order functions such as learning and memory. In the present study, we surveyed for activity-dependent genes by analyzing gene expression changes accompanying reversible inhibition of synaptic activity by tetrodotoxin (TTX) using two types of DNA microarrays; our focused oligo DNA microarray "Synaptoarray" and the commercially available high-density array. Cerebral cortical cells from E18 rat embryos were cultured for 14 days to ensure synaptogenesis, then treated with 1 muM TTX for 48 hr without detectable effect on cell viability. Synaptic density estimated by the amount of Synapsin I and Synaptotagmin I was decreased 21-24% by TTX treatment, but recovered to the control level 48 hr after TTX withdrawal. Comparison of gene expression profiles by competitive hybridization of fluorescently labeled cRNA from TTX-treated and control cells showed an overall downregulation of the genes on the Synaptoarray by TTX-treatment with different recovery rates after TTX withdrawal. With 16 representative genes, microarray data were validated by real-time PCR analysis. Genes most severely downregulated by TTX and upregulated above the control level at 5 hr after TTX withdrawal were munc13-1 (involved in docking and priming of synaptic vesicles) and Shank2 (involved in the postsynaptic scaffold). In addition, comprehensive screening at 5 hr after TTX withdrawal using high density arrays resulted in additional identification of Rgs2, a regulator of trimeric G-protein signaling, as an activity-dependent gene. These three genes are thus likely to be key factors in the regulation of synaptic plasticity. (c) 2007 Wiley-Liss, Inc.