Synergism through combination of chemotherapy and oxidative stress-induced autophagy in A549 lung cancer cells using redox-responsive nanohybrids: A new strategy for cancer therapy

A combination of various therapeutic approaches has emerged as a promising strategy for cancer treatment. A safe and competent nano-delivery system is thus in urgent demand to facilitate the simultaneous transport of various therapeutic agents to cancer cells and a tumor region to achieve synergistic effect. Gold nanoparticles (GNPs) and mesoporous silica nanoparticle (MSNs) were fabricated herein as potential candidates for drug delivery. Serving as gatekeepers, GNPs (5 nm in diameter) were attached onto the amino-functionalized MSNs (denoted as NMSNs) via a relatively weak gold–nitrogen bonding. The resulting nanohybrids (denoted as GCMSNs) were uptaken by cells, and the detachment of GNPs and subsequent intracellular drug release from NMSNs were achieved by competitive binding of intracellular glutathione to GNPs. In addition to the function of gatekeeping, GNPs also play another role as the oxidative stress elicitor. Our in vitro studies revealed that GCMSNs induced higher oxidative stress in lung cancer cells (A549) than in normal cells (3T3-L1). This growth inhibitory effect found in the cancer cells was likely induced by mitochondria dysfunction originated from the GCMSN-induced, oxidative stress-triggered mitochondria-mediated autophagy. The redox-responsive nanohybrids were further loaded with camptothecin and the intensified synergistic therapeutic effects were observed associated with combined chemotherapy and oxidative stress strategy. The results clearly demonstrate that such unique nanohybrids hold great promise for selective and effective cancer treatments.     

Utility of QuantiFERON®-TB Gold In-Tube Test Compared with Tuberculin Skin Test in Diagnosing Tuberculosis in Indian Children with Malnutrition

This prospective cohort study was conducted to compare the accuracy of QuantiFERON®-TB (QFT) Gold In-Tube test and tuberculin skin test (TST) in diagnosing tuberculosis (TB) in predominantly bacille Calmette–Guerin-vaccinated children with a high incidence of malnutrition. The sensitivity of the QFT versus the TST was 69.6% versus 52.9% for WHO-defined TB, with specificity of 86% versus 78.3%, respectively. The concordance of the TST and QFT was 79% overall (κ = 0.430), 62.5% in those with WHO-defined TB and 85.7% in those without TB. Majority of the QFT+/TST − discordance was seen in children with TB, whereas majority of the TST+/QFT − discordance was seen in those without TB. The TST was more likely to be negative in children with moderate-to-severe malnutrition (P = 0.003) compared to the QFT, which was more likely to be positive in younger children. The significantly better performance of the QFT in malnourished children and those at younger ages supports its use for TB diagnosis in these subpopulations.     

三种固定剂对氯化金染色大鼠运动终板效果的比较

目的 对比分析25%甲酸、25%乙酸和4%甲醛3种固定剂对氯化金染色运动终板的效果。方法 选用30只SD大鼠,体重180～220 g,雌雄不拘。进行10次实验,每次实验随机选取3只,取右侧肱二头肌,分别置于25%甲酸、25%乙酸和4%甲醛溶液中固定后,行氯化金镀金法,光学显微镜下观察运动终板的形态结构和背景颜色。结果 3种固定剂固定的运动终板边缘整齐,中央颜色浅于周围,部分运动终板中央呈空泡状。甲酸固定的肌纤维排列有序,横纹清晰,呈紫红色;乙酸固定的肌纤维排列有序,无清晰的横纹,呈紫蓝色,但染色较浅,与运动终板形成的反差较小;甲醛固定的肌纤维排列杂乱,无横纹,呈紫红色、粉红色、紫黑色和蓝色等多种颜色。结论 甲酸固定的运动终板氯化金染色效果优于乙酸和甲醛,甲酸固定的肌组织需要的还原时间少于乙酸和甲醛。因此,进行运动终板染色选择固定剂时,25%甲酸在3种固定试剂中可作为最佳选择。     

极速实时荧光聚合酶链反应与常规方法对新型布尼亚病毒检测的评价

目的探讨极速实时荧光聚合酶链反应(polymerase chain reaction,PCR)、实时荧光PCR、酶联免疫吸附测定(enzyme-linked immunosorbent assay,ELISA)和胶体金免疫层析法(gold immunochromatography assay,GICA)4种方法检测新型布尼亚病毒的特异度和灵敏度,为发热伴血小板减少综合征的早期诊断提供依据。方法采集2017年6月1日至9月30日山东大学附属济南市传染病医院86例临床诊断为发热伴血小板减少综合征患者的血清样本,分别应用极速实时荧光PCR、实时荧光PCR、ELISA和GICA 4种方法进行检测。统计学分析采用χ^2检验。结果86份患者血清标本中,极速实时荧光PCR、实时荧光PCR、IgM-ELISA、IgG-ELISA、IgM-GICA、IgG-GICA的新型布尼亚病毒阳性分别为82份(95.34%)、79份(91.86%)、41份(47.67%)、8份(9.3%)、19份(22.09%)和3份(3.49%)。极速实时荧光PCR特异度为100%,灵敏度达到1×103拷贝/mL,3次重复扩增试验显示其Ct值变异系数均<2%。在发热伴血小板减少综合征进展的1期、2期、3期病程中,极速实时荧光PCR的阳性检出率为41份(97.62%)、34份(94.44%)、7份(87.50%),实时荧光PCR的阳性检出率为39份(92.86%)、33份(91.67%)、7份(87.50%),在1期和2期两个病程,极速实时荧光PCR阳性检出率略高;IgM-ELISA阳性检出率从1期(28.57%)到3期(87.50%)显著增高,2期、3期与1期相比,差异均有统计学意义(χ^2=8.347、7.561,均P<0.01);IgM-GICA的阳性检出率从1期(14.29%)到2期(33.33%)也有增高,差异有统计学意义(χ^2=3.962,P<0.05),但与其他方法相比,其检出率偏低。1期,实时荧光PCR阳性检出率显著高于ELISA(IgM和IgG)和GICA(IgM和IgG),差异均有统计学意义(χ^2=33.740、55.080、49.010、64.340,均P<0.01)。2期,实时荧光PCR的阳性检出率高于ELISA(IgM和IgG)和GICA(IgM和IgG),差异均有统计学意义(χ^2=7.700、46.720、23.700、50.630,均P<0.01)。3期,极速实时荧光PCR、实时荧光PCR和IgM-ELISA表现出同样高的阳性检出率,远高于IgG-ELISA和GICA(IgM和IgG)。实时荧光PCR阳性检出率和IgG-ELISA、IgM-GICA、IgG-GICA之间差异均有统计学意义(均χ^2=6.250,P<0.05)。结论极速实时荧光PCR在新型布尼亚病毒的早期检测中有更高的灵敏度和特异度,且重复性好、稳定度高,与传统实时荧光PCR相比大大缩短了扩增时间,对发热伴血小板减少综合征的早期快速诊断具有重要价值。     

免疫磁珠分离技术纯化和检测泰泽氏病原体的研究

目的建立泰泽氏病原体(Ty)纯化方法,获得纯的菌体供抗原研究,为ELISA诊断抗原的制备提供依据;并尝试建立Ty隐性感染血清学抗原检查方法。方法选择特异性抗体包被磁珠,从感染大鼠肝脏中富集和纯化Ty;用SDS-PAGE和Western blot技术考察纯化Ty的蛋白和抗原图谱;同时用免疫磁珠分离技术(IMS)直接检查隐性感染大鼠肠道上皮细胞内的Ty。结果用辛酸-硫酸铵纯化的Ty单克隆抗体M5以0·5μg/107beads以上浓度包被抗IgG抗体预结合的磁珠4h,可最大效率地富集Ty;分离反应进行1h,敏感性达到103菌体/mL;吖啶黄染色镜检法可以直接、快速地观察到结合于磁珠上的细菌;抗原分析表明,IMS较好地去除了肝组织和真核细胞成分,纯化的Ty RJ株具有3个免疫优势的抗原成分,相对分子质量(Mr)分别为160×103、116×103、55×103;此外,IMS法可直接从隐性感染大鼠盲肠上皮细胞中检测到少量寄生的Ty。结论用IMS技术可有效地富集和纯化Ty,并可以作为Ty隐性感染血清学抗原检查的候选方法。     

比色法测定维生素B1片含量的研究

本文实验比较了某些现有光度测定ＶＢ１方法，提出用盐酸苯肼－亚硝酸钠试剂与维生素Ｂ１反应生成橙红色溶液，进行光度测定，对比度△λ为９１ｎｍ，灵敏度，ε（４９７ｎｍ）＝１．１×１０４Ｌ·ｍｏｌ（－１）·ｃｍ（－１），在０～１０μｇ／ｍｌ范围内线性关系良好。用本法测定维生素Ｂ１片的含量，标准加入回收率范围为１００％～１０３％，片剂测定与中国药典１９９０年版紫外分光光度法测定结果一致。     

~(27)AINMR对碱式氯化铝的研究

实验室制得的碱式氯化铝,用~(27)Al NMR进行分析,发现在众多聚合体中存在[AlO_4Al_(12)(OH)_(24)(H_2O)_(12)]~(7+)离子,其化学位移相对于六水合铝离子[Al(H_2O)_6]~(3+)的零位移为δ=63ppm,试铁灵定时比色法对其存在进行了验证。研究了反应条件如酸浓度、铝酸当量比和陈化时间对产物组成及质量的影响,得出最佳条件为盐酸浓度16%,铝酸当量比为1:0.5,陈化时间为50h左右。     

丁型肝炎抗体诊断试剂的研制

取乙型肝炎患者Delta抗体(抗—HD)阳性血清,经硫酸铵盐析和DE—52柱层析,得到纯化的抗—HD抗体,用辣根过氧化物酶标记。用丁型肝炎病毒(HDV)感染慢性携带土拨鼠肝炎病毒的东方土拨鼠(Woodchuck)后,取其肝组织制成匀浆,离心后经Sepharose 4B柱,免疫亲和层析柱,获得高丰度的HDAg。双抗体夹心法测定其滴度高达1∶10~6。制备成ELISA竞争抑制法检测抗HD试剂盒,其特异性、敏感性、重复性与爱尔兰同种试剂比较结果一致。     

Preparation of tritium‐labeled Silybin—a protectant for common liver diseases

Silymarin, the seed extract of milk thistle plant, Silybum marianum, has been used traditionally for the treatment of liver diseases and bile duct infection. Silybin 1 is the main bioactive components of silymarin, consisting a pair of diastereomers: Silybin A and Silybin B. In this article, we report the preparation of tritium‐labeled Silybin, which was accomplished by protection of Silybin as tritylated compound 2 and followed by oxidation of the primary alcohol to its corresponding aldehyde 3 . Subsequent reduction with NaB[³H]₄ and deprotection of the trityl group provided the tritium‐labeled Silybin 4 . Copyright © 2006 John Wiley & Sons, Ltd.     

超顺磁性氧化铁Resovist标记神经干细胞的实验研究

目的研究超顺磁性氧化铁（superparamgnetic iron oxides，SPIOs）标记神经干细胞及其生物学特性．方法：神经干细胞培养、传代和诱导分化；Resovist（一种SPIOs）标记神经干细胞。制备磁标记神经干细胞；利用免疫细胞化学、透射电镜和Prussian blue染色等方法对磁标记神经干细胞生物学特性进行研究。结果：在原代及传代细胞中有Nestin阳性细胞即神经干细胞．血清诱导下，神经干细胞可分化为GFAP、NF200阳性细胞．Resovist与神经干细胞共同孵育后，透射电镜及Prussian blue染色显示胞浆中含有铁颗粒，Resovist也可以随细胞的分裂增殖而传到子代细胞中。随Resovist浓度的增高（5．6μg／ml-11．2μg/ml），Resovist对神经干细胞存活、分化能力的影响无显著性差异（P〉0．05）．当Resovist的浓度大于22．4μg／ml时。Resovist影响其存活和分化（P〈0．05）。结论：本实验利用Resovist作为磁标记探针，对神经干细胞进行成功磁标记，为进一步利用核磁共振（MRI）对神经干细胞活体追踪奠定实验基础。