新城疫病毒基质蛋白与禽细胞核磷蛋白B23.1在HEK-293T细胞中的相互作用

【目的】探讨新城疫病毒（Newcastle disease virus,NDV）基质（matrix,M）蛋白和禽细胞核磷蛋白B23.1在HEK-293T细胞中的相互作用。【方法】分别参照GenBank中NDV JS/5/05/Go株全基因序列（JN631747）和禽细胞核磷蛋白B23.1基因序列（NM₂05267）,设计、合成扩增M基因和B23.1基因的引物,利用RT-PCR扩增出M基因和DF1细胞的B23.1基因,分别克隆至真核表达载体获得重组表达质粒pEGFP-M、pCMV-HA-M和pDsRed-B23.1;将pEGFP-M和pDsRed-B23.1共转染HEK-293T细胞,利用荧光显微镜观察M蛋白与B23.1蛋白的共定位;利用免疫共沉淀（Co-IP）技术进一步验证两种蛋白的相互作用。【结果】Western blot结果表明构建的重组质粒在转染的HEK-293T细胞中正确表达;荧光显微镜观察显示M蛋白与B23.1蛋白在核仁具有共定位特征;Co-IP进一步证实两者能发生相互作用。【结论】NDV M蛋白与禽细胞核磷蛋白B23.1存在相互作用,M蛋白可能通过与B23.1蛋白的相互作用进入核仁。     

Tissue factor pathway inhibitor-2: A novel gene involved in zebrafish central nervous system development

Tissue factor pathway inhibitor-2 (Tfpi-2) is an important serine protease inhibitor in the extracellular matrix (ECM), but its precise physiological significance remains unknown. This work is part of a series of studies intended to investigate functional roles of Tfpi-2 and explore the underlying molecular mechanisms. First, we cloned and identified zebrafish Tfpi-2 (zTfpi-2) as an evolutionarily conserved protein essential for zebrafish development. We also demonstrated that ztfpi-2 is mainly expressed in the central nervous system (CNS) of zebrafish, and embryonic depletion of ztfpi-2 caused severe CNS defects. In addition, changes of neural markers, including pax2a, egr2b, huC, ngn1, gfap and olig2, confirmed the presence of developmental abnormalities in the relevant regions of ztfpi-2 morphants. Using microarray analysis, we found that members of the Notch pathway, especially her4 and mib, which mediate lateral inhibition in CNS development, were also downregulated. Intriguingly, both her4 and mib were able to partially rescue the ztfpi-2 morphant phenotype. Furthermore, Morpholino knockdown of ztfpi-2 resulted in upregulation of neuronal markers while downregulation of glial markers, providing evidence that the Notch pathway is probably involved in ztfpi-2-mediated CNS development.     

In vitro selection of a DNA aptamer targeted against Shigella dysenteriae

To identify DNA aptamers demonstrating binding specificity for Shigella dysenteriae, a whole-bacterium Systemic Evolution of Ligands by Exponential enrichment (SELEX) method was applied to a combinatorial library of single-stranded DNA (ssDNA) molecules. After several rounds of selection using S. dysenteriae as the target, the highly enriched oligonucleotide pool was sequenced and then grouped into different families based on primary sequence homologies and similarities in the secondary structures. Aptamer S 1, which showed particularly high binding affinity in preliminary studies, was chosen for further characterisation. This aptamer displayed a dissociation constant (K_d value) of 23.47 ± 2.48 nM. Binding assays to assess the specificity of aptamer S 1 showed high binding affinity for S. dysenteriae and low apparent binding affinity for other bacteria. The ssDNA aptamers generated may serve as a new type of molecular probe for microbial pathogens, as it has the potential to overcome the tedious isolation and purification requirements for complex targets.     

Influence of solids retention time on membrane fouling: characterization of extracellular polymeric substances and soluble microbial products

The objective of this study was to investigate the influence of solids retention time (SRT) on membrane fouling and the characteristics of biomacromolecules. Four identical laboratory-scale membrane bioreactors (MBRs) were operated with SRTs for 10, 20, 40 and 80 days. The results indicated that membrane fouling occurred faster and more readily under short SRTs. Fouling resistance was the primary source of filtration resistance. The modified fouling index (MFI) results suggested that the more ready fouling at short SRTs could be attributed to higher concentrations of soluble microbial products (SMP). Fourier transform infrared (FTIR) spectra indicated that the SRT had a weak influence on the functional groups of the total extracellular polymeric substances (TEPS) and SMP. However, the MBR under a short SRT had more low-molecular-weight (MW) compounds (<1 kDa) and fewer high-MW compounds (>100 kDa). Aromatic protein and tryptophan protein-like substances were the dominant groups in the TEPS and SMP, respectively.     

Cranial morphology of an Early Cretaceous Monjurosuchid (Reptilia: Diapsida) from Liaoning Province of China and evolution of the choristoderan palate

A new specimen of Philydrosaurus proseilus from the Early Cretaceous Chiufotang (Jiufotang) Formation preserves the first complete palate of a monjurosuchid choristodere. As in other choristoderes, the palate of Philydrosaurus is akinetic, extended by a broad contact between the vomer and maxilla, and equipped with multiple batteries of palatal teeth. This specimen provides phylogenetically significant information and clarifies the distribution of many apomorphies within Choristodera. Philydrosaurus is primitive relative to the Neochoristodera in that it exhibits only a moderate degree of posterior displacement of the choanae and retains a relatively large interpterygoid vacuity. However, Philydrosaurus also exhibits several derived features previously considered diagnostic of the Neochoristodera, including establishment of a long midline contact of the pterygoids and development of a distinct nasopalatal trough extending from the choana. The choristodere palate exhibits significant modification of the primitive diapsid condition, including elongation of the vomers, establishment of a vomer–maxilla contact, posterior displacement of the choanae, development of the nasopalatal trough, and reduction of the interpterygoid vacuity.     

Synthesis and characterization of 123I-CMICE-013: A potential SPECT myocardial perfusion imaging agent

Coronary artery disease (CAD) is a major cause of death in Canada and the United States. Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is a useful diagnostic test in the management of patients with CAD. The widely used SPECT MPI agents, ^99mTc sestamibi and ^99mTc tetrofosmin, exhibit less than ideal pharmacokinetic properties with decreasing uptake with higher flows. ¹²³I has a similar energy as ^99mTc, an ideal half life, and is readily available from cyclotrons. The objective of this study was to develop an ¹²³I labeled MPI agent based on rotenone, a mitochondrial complex I inhibitor, as an alternative to currently available SPECT MPI agents. Methods: ¹²³I-CMICE-013 was synthesized by radiolabeling rotenone with ¹²³I in trifluoroacetic acid (TFA) with iodogen as the oxidizing agent at 60 °C for 45 min, followed by RP-HPLC purification. The product was formulated in 5% EtOH in 10 mM NaOAc pH 6.5. The inactive analog ¹²⁷I-CMICE-013 was isolated and characterized by NMR and mass spectrometry, and the structure determined. Micro-SPECT imaging studies were carried out in normal and infarcted rats. Biodistribution studies were performed in normal rats at 2 h (n = 6) and 24 h (n = 8) post injection (p.i.). Results: ¹²³I-CMICE-013 was isolated with >95% radiochemical purity and high specific activity (14.8–111 GBq/μmol; 400–3000 mCi/μmol). Structural analysis showed that rotenone was iodinated at 7′-position, with removal of the 6′,7′-double bond, and addition of a hydroxy group at 6′-position. MicroSPECT images in normal rats demonstrated homogeneous and sustained myocardial uptake with minimal interference from lung and liver. Absent myocardial perfusion was clearly identified in rats with permanent left coronary artery ligation and ischemia-reperfusion injury. In vivo biodistribution studies in normal rats at 2 h p.i. showed significant myocardial uptake (2.01 ± 0.48%ID/g) and high heart to liver (2.98 ± 0.93), heart to lung (4.11 ± 1.04) and heart to blood (8.37 ± 3.97) ratios. At 24 h p.i., the majority of ¹²³I-CMICE-013 was cleared from tissues, and a significant amount of tracer was found in the thyroid, indicating in vivo deiodination of the tracer. Conclusion: ¹²³I-CMICE-013 is a promising new radiotracer for SPECT MPI with high myocardial uptake, very good target to background ratios and favorable biodistribution characteristics.     

米诺环素对不完全脊髓损伤大鼠脊髓BDNF和NT-3表达的影响

目的观察腹腔注射米诺环素对改良Allen’s法造成的不完全脊髓损伤大鼠脊髓中脑源性神经营养因子以及神经营养因子3表达的影响,探讨米诺环素治疗脊髓损伤的作用机制。方法成年雌性Sprague-Dawley(SD)大鼠54只,改良Allen’s法造成不完全脊髓损伤,根据实验需要可以分为3组,空白组,只打开脊柱椎板,不损伤;治疗组,大鼠脊髓损伤,并腹腔注射米诺环素;损伤组,大鼠脊髓损伤,腹腔注射等剂量的生理盐水。观察各组大鼠的后肢能力Basso-Beattie-Bresnahan评分,并于不同时段(3d、7d,14d)取大鼠脊髓T8-9段采用逆转录PCR,以及免疫化学组织染色法测定脑源性神经营养因子以及神经营养因子3的表达。结果米诺环素能够明显改善不完全脊髓损伤大鼠的功能,逆转录PCR和脊髓组织冰冻切片免疫组织化学染色DAB都能证实米诺环素治疗组脑源性神经营养因子以及神经营养因子3表达显著增多。结论米诺环素在治疗不完全脊髓损伤大鼠的机制还应与其上调了大鼠体内的脑源性神经营养因子以及神经营养因子3表达有关。     

案例教学法在护理本科专业组织学与胚胎学教学中的实施与体会

组织学与胚胎学为护理本科专业学生必修课.在教学过程中采取＂学生为主体、教师为主导＂的案例教学法,激发学生的主观能动性,注重学生创新能力培养.在案例教学过程中,也发现一些问题：学生素质不一、学习目标不明确以及教师教育理念滞后等.因此,在护理本科专业组织学与胚胎学实施案例教学过程中,引导学生确立学习目标,积极思考,注重团队合作,全面调动学生学习的积极性和主动性.教师在更新教学观念的同时,提倡奉献精神,注重自身素质的培养和提高.     

Inducible transgenic expression in the short‐lived fish Nothobranchius furzeri

This study demonstrates inducible transgenic expression in the exceptionally short‐lived turquoise killifish Nothobranchius furzeri, which is a useful vertebrate model for ageing research. Transgenic N. furzeri bearing a green fluorescent protein (Gfp) containing construct under the control of a heat shock protein 70 promoter were generated, heat shock‐induced and reversible Gfp expression was demonstrated and germline transmission of the transgene to the F1 and F2 generations was achieved. The availability of this inducible transgenic expression system will make the study of ageing‐related antagonistically pleiotropic genes possible using this unique vertebrate model organism.