The influence of Gelatin/PCL ratio and 3-D construct shape of electrospun membranes on cartilage regeneration

Scaffolds play an important role in directing three-dimensional (3-D) cartilage regeneration. Our recent study reported the potential advantages of electrospun gelatin/polycaprolactone (GT/PCL) membranes in regenerating 3-D cartilage. However, it is still unknown whether the changes of GT/PCL ratio have significant influence on 3-D cartilage regeneration. To address this issue, the current study prepared three kinds of electrospun membranes with different GT/PCL ratios (70:30, 50:50, 30:70). Adhesion and proliferation of chondrocytes on the membranes were examined to evaluate biocompatibility of the membranes. Cartilage with different 3-D shapes was engineered to further evaluate the influences of GT/PCL ratio on cartilage regeneration. The current results demonstrated that all the membranes with different GT/PCL ratios presented good biocompatibility with chondrocytes. Nevertheless, the high PCL content in the membranes significantly hampered early 3-D cartilage formation at 3 weeks in vivo. Unexpectedly, at 12 weeks, all the cylinder-shaped constructs formed mature cartilage-like tissue with no statistical differences among groups. To our surprise, ear-shaped cartilage regeneration obtained quite different results again: the high PCL content completely disrupted cartilage regeneration even at 12 weeks, and only the least PCL content group formed homogeneous and continuous cartilage with a satisfactory shape and elasticity similar to human ear. All these results indicated that the high PCL content was unfavorable for 3-D cartilage regeneration, especially for the cartilage with a complicated shape, and that GT/PCL 70:30 might be a relatively suitable ratio for ear-shaped cartilage regeneration. The research models established in the current study provide detailed information for cartilage and other tissue regeneration based on electrospun GT/PCL membranes.     

Inhibition of islet amyloid polypeptide fibril formation by selenium-containing phycocyanin and prevention of beta cell apoptosis

Human islet amyloid polypeptide (hIAPP) fibril is the major constituent of amyloid deposits in pancreatic islets of type 2 diabetes. Misfolding and hIAPP fibril formation are thought to be important in the pathogenesis of diabetes. Studies have showed that selenium-containing phycocyanin (Se-PC) inhibited the fibrillation of hIAPP to form nanoscale particles, which is mainly by interfering with the combination between hIAPP. Small nanoscale oligomers tended to grow into larger nanoparticles and the size of nanoparticles increased with the incubation time. By interfering with the fibrillation of hIAPP and altering the structure, Se-PC alleviated hIAPP-induced cell apoptosis. Meantime, generation of ROS produced during the fibrillation process was inhibited, which was proposed to be the main factor for the hIAPP-cytotoxicity in beta cells. Taken together, Se-PC inhibited hIAPP fibrillation, thus suppressed the formation of ROS to show protective effect on hIAPP mediated cell apoptosis. Our studies provide useful information for our understanding of the interaction mechanisms of Se-PC on hIAPP structure and protective mechanisms on hIAPP cytotoxicity, presenting useful candidate for anti-diabetes drug development.     

Chemerin aggravates DSS-induced colitis by suppressing M2 macrophage polarization

Chemerin is present in various inflammatory sites and is closely involved in tissue inflammation. Recent studies have demonstrated that chemerin treatment can cause either anti-inflammatory or pro-inflammatory effects according to the disease model being investigated. Elevated circulating chemerin was recently found in patients with inflammatory bowel disease （IBD）; however, the role of chemerin in intestinal inflammation remains unknown. In this study, we demonstrated that the administration of exogenous chemerin （aa 17-156） aggravated the severity of dextran sulfate sodium （DSS）-induced colitis, which was characterized by higher clinical scores, extensive mucosal damage and significantly increased local and systemic production of pro-inflammatory cytokines, including IL-6, TNF-a and interferon （IFN-7）. Interestingly, chemerin did not appear to influence the magnitudes of inflammatory infiltrates in the colons, but did result in significantly decreased colonic expression of M2 macrophage-associated genes, including Arginase 1 （Arg-1）, Yml, FIZZ1 and IL-IO, following DSS exposure, suggesting an impaired M2 macrophage skewing in vivo. Furthermore, an in vitro experiment showed that the addition of chemerin directly suppressed M2 macrophage-associated gene expression and STAT6 phosphorylation in IL-4-stimulated macrophages. Significantly elevated chemerin levels were found in colons from DSS-exposed mice and from ulcerative colitis （UC） patients and appeared to positively correlate with disease severity. Moreover, the in vivo administration of neutralizing anti-chemerin antibody significantly improved intestinal inflammation following DSS exposure. Taken together, our findings reveal a pro-inflammatory role for chemerin in DSS-induced colitis and the ability of chemerin to suppress the anti-inflammatory M2 macrophage response. Our study also suggests that upregulated chemerin in inflamed colons may contribute to the pathogenesis of IBD.     

一种视觉假体的视觉显著图提取新方法

目的 一幅图像或场景的显著性区域代表它们的主要内容（显著目标）.由于视觉假体可植入电极的数量有限,只有低分辨率的图像对其才有用,因此提取显著性区域有助于视觉假体捕捉到场景中的显著目标.方法 Itti模型是一个显著性检测模型,它检测到的显著性区域与人的视觉感知有差异,显著目标的边界不明确.笔者去除了Itti模型提取的方向和色彩特征,将红（R）、绿（G）、蓝（B）三基色（RGB）图像转换到对应于HSI颜色空间上的色调（H）、纯度（S）、亮度（I）3个新特征分量,对hti模型进行优化改进.在显著图中,将落在显著目标内的显著点面积与总显著点面积的比值定义为显著图精确度;以显著图精确度为提取显著图方法的测度,对改进前后2种方法进行比较.结果 利用改进方法提取的显著图比Itti模型显著图精确度提高了约20％;在检测显著性区域时所用时间减少近50％.结论 提出了一种用于人工视觉的获取显著目标的方法,本算法可以得到更加精确的显著性结果,且可缩短运行时间.     

干扰NaV1.9对RAW264.7细胞增殖、吞噬和迁移的影响

目的 应用RNA干扰技术沉默RAW264.7小鼠巨噬细胞中电压门控性钠通道(VGSCs/NaVs)α亚单位NaV1.9基因,建立稳定干扰细胞株,并观察其对细胞增殖活性、吞噬能力和迁移功能的影响.方法 通过LipofectamineTM2000将短发夹RNA(shRNA)干扰质粒转染至RAW264.7细胞,经G418筛选获得稳定细胞株.用实时定量聚合酶链反应(RT-PCR)鉴定干扰效率,CCK-8法测定稳定细胞株的增殖活性,流式细胞术检测细胞的细胞周期及吞噬能力,Transwell小室法检测细胞的迁移功能.结果 成功建立稳定干扰NaV1.9的细胞株,RT-PCR法鉴定干扰效率达80％.CCK-8法及流式细胞术结果显示,降低NaV1.9的表达使细胞增殖活性下降(P＜0.05);流式细胞术结果显示,抑制NaV1.9的表达使细胞吞噬能力降低(P＜0.05);Transwell小室法结果显示,干扰NaV1.9的表达使细胞迁移能力减弱(P＜0.05).结论 建立了稳定干扰NaV1.9的RAW264.7细胞株,下调NaV1.9的表达使巨噬细胞增殖活性、吞噬能力和迁移功能显著降低.     

抗T细胞单克隆抗体对再生障碍性贫血患者TNF和IL—2水平的影响

为探讨抗Ｔ淋巴细胞克隆抗体对再生障碍性贫血患者免疫功能的调节作用，采用放射免疫检测２５例ＡＡ患者ＭｃＡｂ－Ｔ治疗前后血清肿瘤坏死因子和白细胞介素－２（ＩＬ－２）水平及其中１０例周围血单个核细胞体外诱生ＴＮＦ和ＩＬ－２水平的变化。     

神经反馈调节健康个体注意力的研究进展

神经反馈是指通过脑机交互方式,将大脑活动转换成声音、图像、游戏等形式反馈给个体,以实现自主调节脑功能的目的。注意力是认知功能的重要方面,不仅是儿童发展成长的影响因素,也是成人日常生活中不可替代的重要心理品质。越来越多的实证研究已经发现神经反馈对健康个体的注意力具有调节作用,但缺乏对相关研究进展的总结和综述。综述基于大脑节律活动的神经反馈对于健康个体注意力调节作用的研究进展,分析注意力测量范式、学习者和非学习者的划分以及实验设计类型对神经反馈训练效果的影响,指出了追踪实验对研究的必要性。同时提及可用于健康个体注意力调节的其他几种神经反馈技术。期望为神经反馈提高注意能力的研究和实践提供参考。     

NLR、CRP及IL-6、IL-17在子宫内膜异位症中的表达及与病情的相关性

目的探讨NLR(中性粒细胞与淋巴细胞比值)、CRP(C反应蛋白)、IL-6(白细胞介素6)、IL-17(白细胞介素17)在子宫内膜异位症(EMs)中的表达水平及其与病情的相关性。方法回顾性分析2017年7月至2019年7月在唐山市妇幼保健院妇科行腹腔镜手术的126例术后病理确诊为EMs的患者作为研究对象,其中Ⅰ~Ⅱ期为轻度组(73例),Ⅲ~Ⅳ期为重度组(53例),选取同期体检的健康妇女50例作为对照组。分别测定各组CRP、IL-6、IL-17及NLR指标的水平,分析各指标的关系并应用Logistic回归分析各指标与EMs严重程度的相关性。结果EMs组患者血清中的CRP、IL-6、IL-17和NLR水平均高于对照组,IL-6分别与IL-17和CRP成正相关(r=0.348,P<0.05;r=0.308,P<0.05),CRP与NLR成正相关(r=0.297,P<0.05)其他指标间无显著相关性。重度组CRP、IL-6、IL-17水平均高于轻度组,差异有统计学意义(P<0.05)NLR重度组与轻度组差异无统计学意义(P>0.05)。Logistic回归分析显示,CRP、IL-6、IL-17与EMs病情均密切相关(P<0.05),三者联合诊断EMs的价值最高。结论CRP、IL-6、IL-17和NLR参与了EMs的发生、发展,三个指标的检测可评估EMs的病情及预后判断,CRP、IL-6、IL-17三个指标联合检测可提高EMs诊断的灵敏度和特异性。     

儿童异基因造血干细胞移植后急性肾损伤临床分析

目的分析儿童异基因造血干细胞移植(allo-HSCT)后急性肾损伤(AKI)的临床特征及危险因素。方法回顾性分析2016年8月至2020年3月于武汉儿童医院血液肿瘤科接受allo-HSCT患儿的临床资料,对比移植预处理开始前及移植后100天血肌酐(Cr)、肌酐清除率(Ccr),以及移植后1年的生存情况;采用logistic回归分析影响AKI发生的危险因素。结果共147例allo-HSCT患儿纳入研究,其中男85例、女62例,接受移植时中位年龄5.5岁(0.7个月～16岁)。其中101例(68.7%)患儿发生AKI,中位时间为移植后24.0(-5.0～91.0)d。二元logistic回归分析显示,移植后急性移植物抗宿主病(aGVHD)、肝窦间隙阻塞综合征(SOS)是AKI发生的独立危险因素(P<0.05)。按pRIFLE诊断标准将发生AKI的101例患儿分为风险期组54例、肾损伤期组31例以及肾衰竭期组16例。不同分期之间患儿Cr以及Ccr差异均有统计学意义(P<0.05),肾衰竭期组Cr较高,Ccr较低。allo-HSCT后随访1年,18例患儿死亡,其中AKI患儿死亡16...     

The characteristics of immune system changes in children who ingested melamine-contaminated powdered formula in China

Since 2008, the food safety issue of melamine poisoning has again become a health scare for children. The mechanism of how melamine initiates kidney stones and kidney-associated renal complications is still unknown. Some children who ingested melamine-contaminated powdered formula had leukocyturia, but none had typical symptoms of urinary tract infection. We believed that the children's immune systems might have some changes. We followed up 170 children who ingested melamine-contaminated powdered formula and tested their blood and urine and to observe their immune state, and also performed ultrasonography. In the immune responses of children with stones, immunoglobulin M takes a major immune response and the level of CD3⁺, CD4⁺ decreased compared with children without stones. There was no difference in complete blood count between the children with stones and those without stones. We concluded that leukocyturia had a certain relationship with non-urinary tract infectious renal disease and these children are susceptible to infectious diseases.