Use of a multiplex PCR-based reverse line blot (mPCR/RLB) hybridisation assay for the rapid identification of bacterial pathogens.

The aim of this study was to develop a sensitive and reliable method for the molecular identification of pathogenic bacteria. A multiplex PCR-based reverse line blot (mPCR/RLB) hybridisation assay was developed and evaluated for the rapid identification of 24 systemic and respiratory bacterial pathogens in routine diagnosis. All species-specific probes designed for the RLB hybridised with amplified DNA only from the corresponding species. Sensitivity limits of the mPCR/RLB assay varied among the 24 target organisms from 0.05 pg to 0.5 ng of genomic DNA. The sensitivity of the assay was 2 x 10(2) CFU/mL for Streptococcus pneumoniae and 6 x 10(2) CFU/mL for Escherichia coli. The specificity of each probe was tested against 24 species. There were no cross-reactions among any of the 43 probes. The mPCR/RLB assay appeared to be a useful alternative tool for the molecular identification of common pathogens.     

Hydrogen peroxide-induced Ca responses in CNS pericytes

Objective: The aims of the present study were to elucidate the interaction of reactive oxygen species (ROS) and Ca²⁺ response in central nervous system (CNS) pericytes. Methods: The intracellular Ca²⁺ concentration was measured using fluorescent Ca²⁺ indicator, fura-2, in cultured CNS pericytes. Results: Hydrogen peroxide evoked a dose-dependent increase in cytosolic Ca²⁺, which was completely inhibited by catalase. Removal of external Ca²⁺ or addition of nicardipine (1 μM) during application of hydrogen peroxide did not affect Ca²⁺ response. Incubation of the cells in Ca²⁺ free solution did not abolish but slightly reduced Ca²⁺ response by hydrogen peroxide. Ca²⁺ response to hydrogen peroxide was not altered by the depletion of intracellular Ca²⁺ by thapsigargin (1 μM). Pretreatment of the cells with tyrosine kinase inhibitor genistein (100 μM) or tyrphostin A47 (30 μM) significantly reduced Ca²⁺ increase by hydrogen peroxide. Conclusions: These results indicate that hydrogen peroxide evokes Ca²⁺ increase predominantly by release from intracellular Ca²⁺ store, which may be regulated by tyrosine kinases.     

线粒体ATP敏感性钾通道参与超极化停搏的心肌保护作用

目的：探讨线粒体ATP敏感性钾通道（mitoKATP）开放在超极化停搏心肌保护中的作用机制。方法:将SD大鼠随机分为对照组（Control）、去极化停搏组（D）、超极化停搏组（H）、5-羟葵酸(5-HD) +去极化停搏组（5HD+D）、5-HD+超极化停搏组（5HD+H），每组8例。建立Langendorff灌注模型，平衡20 min，以不同方式停搏40 min，再灌注30 min，对比观察：(1)不同时间血流动力学变化；(2)再灌注末取心肌并分离、制备线粒体，电镜观察超微结构的变化。(3)平衡末、再灌注末线粒体活性氧的产生。结果: (1)各组再灌注末大鼠心脏功能明显低于平衡末, 心肌线粒体超微结构均遭受不同程度损伤，左室发展压（LVDP）、左室舒张末压（LVEDP）、率压双乘积（DP）、冠脉流量（CF）有显著差异（P<0.01）；（2）超极化停博组再灌注末心脏功能指标LVDP、LVEDP、DP、CF明显优于去极化停博组、5-HD+超极化停搏组、5-HD+去极化停搏组、对照组（P<0.01），电镜示：心肌、线粒体超微结构遭受的损伤较轻; (3)超极化停博组再灌注末心肌线粒体活性氧产生率低于对照组与其它3组（P<0.01）。结论:(1)超极化停搏能明显改善再灌注后心功能，保护心肌、线粒体超微结构，减少活性氧生成；(2)mitoKATP的早期开放参与超极化停搏，其作用可能通过保护再灌注后的线粒体呼吸功能，减轻线粒体的氧化损伤，为再灌注心肌提供较好的能量供应，从而使缺血再灌注后的心脏收缩功能得到一定恢复。     

Extraction of organic acids by ion-pair extraction with tri-n-octylamine - VIII. Identification of synthetic dyes in pharmaceutical preparations

Synthetic dyes were extracted from syrups, oral suspensions, tablets, gelatin capsules, suppositories and granules by ion-pair formation with tri-n-octylamine (TnOA) and back-extracted with perchlorate ions. Identification was performed by TLC on cellulose layers and by reversed phase ion-pair HPLC.     

Model identification and estimation of organ-function parameters using radioactive tracers and the impulse-response function

Examination of the input-output events in functioning organs by the use of the impulse-response function (IRF) for a radioactive tracer is gaining more and more ground in nuclear medicine. This study summarizes the development of deconvolution analysis, laying special stress on the model-free approach. System linearity and time invariance are discussed, and means of eliminating noise in IRFs originating from the input and organ-time-activity curves are outlined. Typical IRFs are illustrated by flow diagrams, time-domain curves, and their representation by Laplace transforms. The cases of nondiffusible and diffusible tracers as well as parenchymally extracted and transported substances are discussed. Methods for the derivation of models and for the calculation of physiologically important parameters from theIRFs are suggested.At present, a guest scientist at the Institute for Medicine, Nuclear Research Center Jülich, Jülich, Federal Republic of Germany     

基于转录组数据的半夏AP2/ERF基因家族鉴定及逆境响应分析

目的：鉴定并研究半夏AP2/ERF转录因子的功能,为推进半夏品种的遗传改良提供理论依据。方法：该文基于半夏三代转录组数据鉴定了半夏中AP2/ERF家族成员,并对其进行系统的生物信息学分析,同时利用实时荧光定量聚合酶链式反应（Real-time PCR）检测半夏AP2/ERF在不同组织及不同胁迫条件下的表达情况。结果：通过转录组数据共筛选出8个全长AP2/ERF转录因子家族成员,归为AP2、ERF和DREB 3个亚家族;半夏AP2/ERF的氨基酸数目为251～512个,等电点为5.29～11.72,不稳定指数为45.90～82.41,且主要定位于细胞核中;半夏AP2/ERF基因的结构域和Motifs相对保守。组织特异性表达模式分析显示,半夏AP2/ERF基因在不同组织部位中具有不同的表达模式,且主要在叶中表达。逆境胁迫应答分析表明,PtERF1主要响应NaCl的胁迫诱导;PtERF2和PtERF4在低温和聚乙二醇（PEG）胁迫下表达量均有较大幅度的上调;PtERF3同时响应低温和NaCl两种逆境的诱导;PtERF5同时响应高温、低温、NaCl、PEG胁迫诱导;PtERF7在高温胁迫下表达...     

电子鼻技术应用于白及及其近似饮片快速辨识的可行性分析

目的：探讨电子鼻技术应用于白及及其近似饮片快速辨识的可行性。方法：收集134批白及及其近似饮片（白及45批、天麻30批、玉竹30批、黄花白及29批）作为待测样品,使用PEN3型电子鼻采集样品嗅觉感官数据作为自变量X,基于2020年版《中华人民共和国药典》和地方标准的鉴别结果,以及各饮片高效液相色谱法（HPLC）指纹图谱和原始采购信息,获得辨识模型的标杆数据Y,分别采用主成分分析-判别分析（PCA-DA）、偏最小二乘法-判别分析（PLS-DA）、最小二乘法-支持向量机（LS-SVM）及K-最近邻（KNN）4种化学计量学方法建立45批白及与89批非白及的二分类辨识模型和上述4种饮片的四分类辨识模型Y=F(X)。结果：经留一法交互验证,在二分类辨识中,上述4种模型分类正判率分别为97.01%、97.01%、98.51%和97.01%;在四分类辨识中,这4种模型分类正判率分别为97.76%、89.55%、98.51%和97.01%。二分类和四分类辨识模型的最高正判率均可达到98.51%,且均以LS-SVM算法为最优,最优核函数分别选择径向基核函数和线性核函数。最优模型判别结果良好,没有未分类样...     

Self-Reported Frailty Screening Tools: Comparing Construct Validity of the Frailty Phenotype Questionnaire and FRAIL

ObjectivesWe examined the construct validity of 2 self-reported frailty questionnaires, the Frailty Phenotype Questionnaire (FPQ) and FRAIL, against the Cardiovascular Health Study frailty phenotype (CHS-FP).DesignCross-sectional data analysis of longitudinal prospective cohort study.Settings and ParticipantsWe included data from 230 older adults (mean age: 67.2 ± 7.4 years) from the “Longitudinal Assessment of Biomarkers for characterization of early Sarcopenia and Osteosarcopenic Obesity in predicting frailty and functional decline in community-dwelling Asian older adults Study” (GeriLABS 2) recruited between December 2017 and March 2019.MethodsWe compared area under receiver operating characteristic curves (AUC), agreement, correlation, and predictive validity against outcome measures [Short Physical Performance Battery, 5 times repeat chair stand (RCS-5), Frenchay activities index, International Physical Activity Questionnaire, life-space assessment, Social Functioning Scale 8 (SFS-8), EuroQol-5 dimensions (utility value)] using logistic regression adjusted for age, gender, and vascular risk factors. We examined concurrent validity across robust versus prefrail/frail for inflammatory blood biomarkers [tumor necrosis factor receptor 1 and C-reactive protein (CRP)] and dual-energy x-ray absorptiometry body composition [bone mineral density (BMD); appendicular lean mass index (ALMI), and fat mass index (FMI)].ResultsPrevalence of prefrail/frail was 25.7%, 14.8%, and 48.3% for FPQ, FRAIL, and CHS-FP, respectively. Compared with FRAIL, FPQ had better diagnostic performance (AUC = 0.617 vs 0.531, P = .002; sensitivity = 37.8% vs 18.0%; specificity = 85.6% vs 88.2%) and agreement (AC1-Stat = 0.303 vs 0.197). FPQ showed good predictive validity [RCS-5: odds ratio (OR) 2.38; 95% CI: 1.17–4.86; International Physical Activity Questionnaire: OR 3.62; 95% CI:1.78–7.34; SFS-8: OR 2.11; 95% CI: 1.64–5.89 vs FRAIL: all P > .05]. Only FRAIL showed concurrent validity for CRP, compared with both FPQ and FRAIL for TNF-R1. FRAIL showed better concurrent validity for BMD, FMI, and possibly ALMI, unlike FPQ (all P > .05).Conclusions and ImplicationsOur results support complementary validity of FPQ and FRAIL in independent community-dwelling older adults. FPQ has increased case detection sensitivity with good predictive validity, whereas FRAIL demonstrates concurrent validity for inflammation and body composition. With better diagnostic performance and validity for blood biomarkers and clinical outcomes, FPQ has utility for early frailty detection in the community setting.     

活性氧对红细胞膜流动性影响的研究

目的 :研究活性氧诱导红细胞发生氧化溶血的机制。方法 :用不同浓度的 H2 O2 作用于离体正常红细胞 ,分别用比色法、硫代巴比妥酸荧光法、荧光偏振法测定红细胞溶血度、红细胞膜脂质过氧化物 (L PO)、红细胞膜微粘度。结果 :5 0 ,10 0 ,12 0 mm ol/ L 浓度的 H2 O2 作用于红细胞后 ,均引起红细胞发生氧化溶血 ,红细胞溶血度、红细胞膜 L PO、红细胞膜微粘度均明显增加 ;H2 O2 在 5 0～ 12 0 mm ol· L- 1浓度范围内 ,红细胞溶血度、红细胞膜 L PO、红细胞膜微粘度的增加与 H2 O2 有明显的量效关系 ;红细胞膜微粘度与红细胞溶血度呈明显正相关 ,红细胞膜 L PO与红细胞膜微粘度呈明显正关。结论 :活性氧引发红细胞膜脂质过氧化导致红细胞膜流动性降低在活性氧诱导红细胞发生氧化溶血的机制中起一定的作用