肠激酶特点及其基因工程的研究进展

肠激酶是从哺乳动物体内提取的一种丝氨酸蛋白酶,广泛应用于基因T程领域切割融合蛋白。文章对肠激酶的特点及其基因工程研究进展进行了综述。     

Magnetic resonance imaging of soft tissue tumors

This article outlines the ability of MR imaging in staging, grading, tissue characterization, and posttherapeutic surveillance of soft tissue tumors. Well-known staging parameters, such as extent, relationship with adjacent structures, and detection of intralesional necrosis, are used in the MR protocol for locoregional staging. Bone scintigraphy and high-resolution CT scan of the lungs are best methods for ruling out metastatic spread. A variety of (solitary or combinations of) grading parameters are described in the radiological literature. The role of MR imaging is to afford recognition of these lesions that need further aggressive work-up, excluding all others. Despite controversial reports, the definite role of MR imaging in grading of soft tissue tumors seems to become established. As for grading, a lot of individual imaging characteristics used for tissue characterization have low sensitivity, but combinations of parameters (age, site, signal intensities) are more useful and often allow to predict a specific diagnosis or to narrow down the list of differential diagnoses. Local recurrences of soft tissue tumors are frequent and can be detected accurately by an easy-to-use MR algorithm.     

A nanoparticulate drug-delivery system for glaucocalyxin A: formulation,characterization, increased in vitro,and vivo antitumor activity

Glaucocalyxin A (GLA) is a phytochemical component with multiple pharmacological activities; however, glaucocalyxin A's wider use has been restricted by its poor solubility. In this study, GLA nanosuspensions were prepared with precipitation-combined ultrasonication and were characterized by dynamic light scattering (DLS), transmission electron microscope (TEM), and differential scanning calorimetry (DSC). The GLA nanosuspensions were spherical with a smooth surface and a small size of 143?nm, the drug payload achieved 8.95%, and the maximum GLA concentration reached 1?mg/mL. The lyophilized powders for the GLA nanosuspensions were amorphous and displayed a biphasic drug release pattern with an initial burst release and a consequent sustained release. In contrast to the free drug solution, GLA nanosuspensions showed higher in vitro antitumor activity against HepG2 cells (IC₅₀ value of 1.793 versus 2.884?μg/mL at 24?h, p?<?0.01). Meanwhile, nanosuspensions displayed better anticancer efficacy than free GLA on H22 bearing mice (54.11% versus 36.02% tumor inhibition rate). These results indicate that GLA nanosuspensions have great potential for the treatment of hepatic cancer.     

中药标准组分的高效液相色谱/质谱联用(HPLC/MS)表征

高效液相色谱／质谱联用表征是化学表征的重要内容，本文通过高效液相色谱／质谱联用方法系统表征中药标准组分，采用了电喷雾电离源（ESI）、大气压化学电离源（APCI）的正负离子扫描模式，荻取标准组分在统一分析条件下，不同表征模式中化合物的光谱、质谱信息。通过对不同标准组分中大量表征数据的比对和分析可发现和归纳色谱、质谱规律，用于不同药材的成分差异性研究，以及由系统制备得到的同种药材不同层次标准组分中成分与含量的变化，为制备成分的确定和高效制备条件及参数的优化提供基础。建立包含分析方法的标准组分色谱质谱数据库，结合色谱、质谱规律，实现已知化合物的搜索匹配与自动质谱解析；预测和发现结构类似的未知化合物，提高研究效率，加强中药物质基础研究的系统性和深入性。     

Isolation and characterization of degradation impurities in docetaxel drug substance and its formulation

The degradation of docetaxel drug substance and its injection formulation has been investigated. The majority of impurities were observed in a base degradation study and all five degradation products were characterized. These impurities were isolated, enriched and were subjected to mass and NMR spectral studies. Based on the spectral data, these were characterized as 10-deacetyl baccatin III, 7-epi-10-deacetyl baccatin III, 7-epi-10-oxo-10-deacetyl baccatin III, 7-epi docetaxel and 7-epi-10-oxo-docetaxel, respectively. The last two impurities were also detected in the stability study of docetaxel formulation. Out of these degradation impurities two substances have been previously identified while the other three previously unreported.     

Smith抗原的性质特征及临床意义

系统性红斑狼疮（SLE）是一种自身免疫性疾病，患者血清中可检出多种自身抗体，但抗Smith（Sm）抗体是SLE的标记性抗体。作者就Sm抗原的理化特性、生物学作用和抗Sm抗体的检测作一综述。     

Selective separation,detection of zotepine and mass spectral characterization of degradants by LC–MS/MS/QTOF

A simple, precise, accurate stability-indicating gradient reversed-phase high-performance liquid chromatographic (RP–HPLC) method was developed for the quantitative determination of zotepine (ZTP) in bulk and pharmaceutical dosage forms in the presence of its degradation products (DPs). The method was developed using Phenomenex C₁₈ column (250 mm×4.6 mm i.d., 5 µm) with a mobile phase containing a gradient mixture of solvents, A (0.05% trifluoroacetic acid (TFA), pH=3.0) and B (acetonitrile). The eluted compounds were monitored at 254 nm; the run time was within 20.0 min, in which ZTP and its DPs were well separated, with a resolution of >1.5. The stress testing of ZTP was carried out under acidic, alkaline, neutral hydrolysis, oxidative, photolytic and thermal stress conditions. ZTP was found to degrade significantly in acidic, photolytic, thermal and oxidative stress conditions and remain stable in basic and neutral conditions. The developed method was validated with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness as per ICH guidelines. This method was also suitable for the assay determination of ZTP in pharmaceutical dosage forms. The DPs were characterized by LC–MS/MS and their fragmentation pathways were proposed.     

Isolation and characterization of beta 1-adrenergic receptors from adult, rat cardiac myocytes

The beta-receptors were isolated from rat cardiac myocytes and characterized. Isolated myocytes were prepared from adult rat hearts and characterized for viability. Membrane proteins were solubilized from myocytes with 1% Triton X-102. The solubilized membrane proteins were fractionated by DEAE-Sephacel ion exchange column chromatography. Two major protein peaks were obtained. The second protein peak sample was found to contain beta-receptors to which 125I-15-(4'-azido-3'-iodobenzyl)-carazolol (125I-ABC) was specifically bound. This sample was labeled covalently with 125I-ABC by UV irradiation. The radiolabeled sample was applied to a Sepharose CL-6B gel column. Two radiolabeled protein peaks, one with a molecular weight of approximately 570,000 and the other with a molecular weight of approximately 95,000 were found. When the 570,000-dalton complex was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions, it was dissociated into a component with a molecular weight of 66,000. The 95,000-dalton complex was dissociated into a 58,000-dalton component upon SDS-PAGE under reducing conditions. An excess amount of isoproterenol and propranolol decreased photolabeling of the beta-receptors with 125I-ABC by 60% and 40%, respectively.     

大劣按蚊Torso-like基因鉴定 分子结构及表达特征

目的　鉴定大劣按蚊Torso?like（tsl）基因及表达特征,为深入研究tsl基因功能提供理论基础。方法　根据黑腹果蝇和冈比亚按蚊tsl基因,检索大劣按蚊全基因组并鉴别大劣按蚊tsl基因,设计特异性引物,并采用PCR和逆转录PCR技术扩增目的基因。利用生物信息学软件分析tsl基因编码TSL蛋白的理化性质、信号肽、跨膜结构、蛋白质二级结构和三级结构,并进行系统发育进化分析。利用实时荧光定量PCR技术检测该基因在大劣按蚊各组织中的表达水平。结果　大劣按蚊tsl基因全长16 751 bp,CDS区长1 134 bp,编码377个氨基酸。TSL蛋白属于亲水性稳定蛋白。经生物信息学预测,TSL蛋白为位于膜外的分泌蛋白,且包含信号肽;其二级结构含α?螺旋（51.72%）、延伸链（12.20%）、β?折叠（4.78%）和无规则卷曲（31.30%）,且能以5cj9.1.A为模板进行3D同源建模。系统发育进化分析发现大劣按蚊TSL蛋白与法老按蚊TSL蛋白亲缘关系较近。实时荧光定量PCR检测显示,tsl基因在大劣按蚊头、胸、腹、足均有表达,且在头部表达量最高、足部表达量较低。结论　本研究从基因组水平鉴定了大劣按蚊tsl基因,分析了其蛋白结构及组织特异性表达特征,为进一步深入研究该基因功能奠定了基础。