基于ISSR的地黄栽培品种与野生群体遗传多样性研究

目的 基于ISSR分子标记研究地黄Rehmannia glutinosa栽培品种与野生群体遗传多样性，比较它们的遗传多样性差异，构建它们之间亲缘关系，为地黄种质资源保护及新品种选育提供参考。方法 应用ISSR分子标记技术对地黄栽培品种，野生群体及其近缘种106个样品进行分析，利用POPGEN软件分析Nei’s基因多样性指数（H）等遗传信息参数，应用NTSYS软件构建亲缘关系UPGMA聚类图。结果 7条引物在所有取样群体中，共检测到85个位点，其中多态性位点83个，多态位点百分率（PPB）为97.65%。地黄栽培品种与野生群体及其近缘种的种群间H值为0.265 9，Shannon’s多样性信息指数（I）为0.412 5。地黄栽培品种的多态性位点26个，PPB为30.59%。河南省地黄野生群体多态性位点71个，PPB为83.53%。ISSR聚类分析结果显示地黄栽培品种，野生群体及其近缘种共分成7个组。结论 ISSR分子标记揭示地黄野生群体比栽培品种具有更高的遗传多样性，河南分布的野生地黄群体的遗传多性高于其他地区，与其作为栽培地黄的道地产区，具有一定的相关性。地黄野生群体间亲缘关系与其地理分布格局并无明显相关性。     

消渴方加减对气阴两虚夹瘀型糖尿病肾病的内皮损伤、氧化应激及生化指标的影响

目的:探究消渴方加减对气阴两虚夹瘀型糖尿病肾病(DN)的内皮损伤、氧化应激及生化指标的影响。方法:随机将2017年9月至2018年6月河南省中医院收治的94例DN患者分为两组,各47例,对照组采用静脉滴注还原型谷胱甘肽注射液进行治疗,在对照组的基础上,观察组给予消渴方加减进行治疗。于治疗前后,观察两组的症状评分、空腹血糖(FBG),餐后2 h血糖(2 h PG),谷胱甘肽过氧化物酶(GSH-Px),超氧化物歧化酶(SOD),丙二醛(MDA),白细胞介素-1β(IL-1β),IL-6,超敏C反应蛋白(hs-CRP),肿瘤坏死因子-α(TNF-α),组织型血纤维蛋白溶酶原激活物(t-PA),1型组织纤溶酶原激活物抑制物(PAI-1),血肌酐(SCr),血尿素氮(BUN),一氧化氮(NO),内皮素-1(ET-1),24 h尿总蛋白水平,并观察两组的疗效。结果:治疗后,观察组治疗总有效率为89.36%,高于对照组的74.47%(Z=3.949,P0.05);观察组治疗后的口渴喜饮、倦怠乏力、气短、心悸、心烦、失眠、头晕耳鸣等中医症状评分低于对照组(P0.05);观察组治疗后的FBG,2 h PG,SCr,BUN,24 h尿总蛋白,ET-1,MDA,IL-1β,IL-6,hs-CRP,TNF-α,PAI-1水平低于对照组(P0.05),NO,SOD,GSP-Px,t-PA水平升高(P0.05)。结论:消渴方加减治疗气阴两虚夹瘀型DN效果显著,促进临床症状的改善,促进机体凝血纤溶系统平衡的恢复,抑制炎症反应及氧化应激反应,保护内皮功能及肾功能。     

智能一体化蒸馏——离子色谱法测定小麦粉中双乙酸钠

目的引入智能一体化蒸馏前处理方法,建立离子色谱-电导法测定小麦粉中双乙酸钠的检测方法。方法小麦粉样品采用智能一体化蒸馏仪蒸馏提取,蒸馏液用磷酸溶液调节pH值为3后定容,定容液经IonPac AS11阴离子交换柱分离,KOH淋洗液梯度淋洗,流速为1.0 ml/min,抑制性电导检测器检测,外标法峰面积定量。结果一体化蒸馏法可去除基质中不易挥发的离子,离子色谱-电导法可排除紫外末端吸收的干扰,提高了测定的准确性与灵敏度。该方法在0.004 mg/ml^0.05 mg/ml浓度时线性关系良好,相关系数(r)≥0.999,检出限为0.02 g/kg,采用低、中、高3个浓度加标,回收率在99.4%~102.2%,相对标准偏差(RSD)在1.37%~3.57%(n=6)。结论该方法操作简单快捷,重现性好,灵敏度高,可用于小麦粉中双乙酸钠含量的测定。     

苦参凝胶临床应用指导意见

坤立舒~?苦参凝胶具有抗菌消炎的功效,是国内首个阴道用卡波姆凝胶剂。临床上常用于治疗女性下生殖道感染,其安全性和有效性得到高度认可。现代药理学研究表明,苦参凝胶及其主要成分苦参总碱具有抑菌杀虫、抗炎、抗病毒、镇痛止痒、促进黏膜修复、恢复乳杆菌增殖等药理作用。临床研究显示,苦参凝胶单用或联合其他药物治疗细菌性阴道病、外阴阴道假丝酵母菌病、滴虫阴道炎、混合性阴道炎、萎缩性阴道炎,可显著改善患者临床症状,提高疾病的治疗有效率,恢复阴道微生态,降低复发率。此外,对于宫颈人乳头瘤病毒(human papillomavirus,HPV)感染、慢性子宫颈炎患者也具有显著疗效。结合文献证据及临床专家用药经验,对苦参凝胶的药理药效研究、临床研究、临床应用及药物安全性进行归纳总结,形成苦参凝胶临床应用指导意见,以规范临床医生合理应用苦参凝胶治疗女性下生殖道感染。     

Accuracy of latent-variable estimation in Bayesian semi-supervised learning

Hierarchical probabilistic models, such as Gaussian mixture models, are widely used for unsupervised learning tasks. These models consist of observable and latent variables, which represent the observable data and the underlying data-generation process, respectively. Unsupervised learning tasks, such as cluster analysis, are regarded as estimations of latent variables based on the observable ones. The estimation of latent variables in semi-supervised learning, where some labels are observed, will be more precise than that in unsupervised, and one of the concerns is to clarify the effect of the labeled data. However, there has not been sufficient theoretical analysis of the accuracy of the estimation of latent variables. In a previous study, a distribution-based error function was formulated, and its asymptotic form was calculated for unsupervised learning with generative models. It has been shown that, for the estimation of latent variables, the Bayes method is more accurate than the maximum-likelihood method. The present paper reveals the asymptotic forms of the error function in Bayesian semi-supervised learning for both discriminative and generative models. The results show that the generative model, which uses all of the given data, performs better when the model is well specified.     

Au nanoparticles decorated C60 nanoparticle-based label-free electrochemiluminesence aptasensor via a novel “on-off-on” switch system

Herein, a label-free electrochemiluminescence (ECL) aptasensor for highly sensitive determination of kanamycin was developed based on a novel “on-off-on” switch system. The first “switch on” state with remarkably high ECL intensity was obtained by the tri-layer composite films modified glassy carbon electrode towards the S₂O₈²⁻-O₂ system. To be specific, the first layer was the Au nanoparticles decorated C₆₀ nanoparticles (abbreviation as Au@nano-C₆₀) as inner-layer which was prepared by the in situ generating of Au nanoparticles onto the surface of bovine serum albumin decorated nano-C₆₀ nanoparticles. Then poly-l-histidine was first selected as a novel coreactant of S₂O₈²⁻-O₂ system and it was adsorbed on the Au@nano-C₆₀ modified electrode as inter-layer. Finally, a self-assembling layer of colloidal Au nanoparticles (AuNPs) was the outer-layer. The three layers were interaction by the Au–N covalent bond which could achieve a desirable initial amplified ECL signal. Successively, the capture probes (CPs) of the aptamer for the target of kanamycin was anchored on the resultant tri-layer composite films modified electrode. Later, the “switch off” state was made by the quenching effect of hemin/G-quadruplex DNAzymes towards S₂O₈²⁻-O₂ system according to the DNA hybridization reaction of an assistant probes (APs, guanine-rich nucleic acid) with CPs which could generate a large amount of hemin/G-quadruplex DNAzymes in the presence of hemin with a simple and label-free process. As expected, the second “switch on” state was the ECL signal recovery when the target of kanamycin was present, it is attributed to that the formation of the aptamer–kanamycin complex makes the quencher of hemin/G-quadruplex DNAzymes release from the sensing interface. With the association of “on-off-on” switch system, a linear response about 9 orders of magnitude for kanamycin detection was obtained from 0.15 nM to 170 mm as well as a detection limit down to 45 pM.     

基于凝集素基因对部分隐孢子虫种类的分子鉴定

目的 为了解隐孢子虫凝集素基因在不同分离株的序列差异及其遗传进化关系,以SSU rRNA基因作参照,评价Lectin基因位点作为隐孢子虫基因分型和进化关系分析的可行性。方法 采用巢式PCR,分别在Lectin和SSU rRNA位点处对本实验室分离保存的多个隐孢子虫分离株进行PCR的扩增。用Clustalx对扩增序列与参考序列进行比对,用MEGA5中的邻近法(Neighbor joining method NJ),进行进化树的构建。结果 基于Lectin基因位点,在C. parvum、C. hominis、C. cuniculus及其在SSU rRNA 处与人源C. hominis极为相近的horse genotype、驴源C. hominis均成功扩增出了大小在450 bp左右的目的 条带,并进行了进化树的分析,不同种类和同种不同动物来源的隐孢子虫分布在不同的分支上。结论 Lectin基因位点可很好的区分SSU rRNA序列极为相似的几种隐孢子虫,有望为人兽共患隐孢子虫分类和遗传研究提供新的基因靶标。     

基于HMGB1/TLR4/NF-κB通路探讨桃仁承气汤调节肠源性脓毒症大鼠肠道肌电活动及微环境稳态的作用机制

目的:基于高迁移率族蛋白B1(HMGB1)/Toll样受体4(TLR4)/核转录因子-κB(NF-κB)通路研究桃仁承气汤调节肠源性脓毒症大鼠肠道肌电活动及微环境稳态的作用机制。方法:60只SD大鼠随机分为假手术组、模型组、甘草酸(HMGB1抑制剂,0. 03 g·kg~(-1))组、桃仁承气汤(10 g·kg~(-1))组、甘草酸+桃仁承气汤(0. 03 g·kg~(-1)+10 g·kg~(-1))组,每组12只。除假手术组外,其余各组建立肠源性脓毒症大鼠模型,各组分别以药物处理后,采用苏木素-伊红(HE)染色检测各组大鼠小肠黏膜组织病理改变,比较黏膜厚度、绒毛高度变化;采用试剂盒检测各组大鼠小肠黏膜组织分泌型免疫球蛋白A(sIgA)含量,血清二胺氧化酶(DAO)及D-乳酸水平;检测各组大鼠肠道肌电活动,比较小肠平滑肌慢波频率、慢波振幅;检测各组大鼠肠道菌群,比较大肠埃希菌、双歧杆菌和乳酸杆菌含量;采用蛋白免疫印迹法(Western blot)检测小肠组织中HMGB1/TLR4/NF-κB通路蛋白HMGB1,TLR4,MyD88,NF-κB p65表达情况。结果:与假手术组比较,模型组大鼠小肠黏膜组织绒毛高度、黏膜厚度,sIgA含量,平滑肌慢波频率及振幅、肠道双歧杆菌及乳酸杆菌含量显著降低,血清DAO及D-乳酸水平、肠道大肠埃希菌含量、小肠组织HMGB1,TLR4,MyD88及NF-κB p65蛋白表达明显升高(P0. 05);与模型组比较,桃仁承气汤组、甘草酸组、甘草酸+桃仁承气汤组大鼠小肠黏膜组织绒毛高度、黏膜厚度,sIgA含量、平滑肌慢波频率及振幅、肠道双歧杆菌及乳酸杆菌含量升高,血清DAO及D-乳酸水平、肠道大肠埃希菌含量、小肠组织HMGB1,TLR4,MyD88及NF-κB p65蛋白表达降低(P0. 05);与桃仁承气汤组、甘草酸组分别比较,甘草酸+桃仁承气汤组大鼠小肠黏膜组织绒毛高度、黏膜厚度,sIgA含量、平滑肌慢波频率及振幅、肠道双歧杆菌及乳酸杆菌含量升高,血清DAO及D-乳酸水平、肠道大肠埃希菌含量、小肠组织HMGB1,TLR4,MyD88及NF-κB p65蛋白表达降低,差异均有统计学意义(P0. 05)。结论:桃仁承气汤可减轻小肠黏膜损伤,调控肠源性脓毒症大鼠肠道肌电活动及微环境稳态,恢复肠道功能,保持菌群平衡,可能是通过下调HMGB1/TLR4/NF-κB通路实现的。