Studies on interaction between Vitamin B12 and human serum albumin

The binding reaction between Vitamin B12 (B12, cyanocobalamin) and human serum albumin (HSA) was investigated by fluorescence quenching, UV–vis absorption and circular dichroism (CD) spectroscopy. Under simulative physiological conditions, fluorescence quenching data revealed that the quenching constants (K_sv) are 3.99 × 10⁴, 4.33 × 10⁴, 4.76 × 10⁴ and 5.16 × 10⁴ M⁻¹ at 292, 298, 304 and 310 K, respectively. The number of binding sites, n is almost constant around 1.0. On the basis of the results of fluorescence quenching the mechanism of the interaction of B12 with HSA has been found to be a dynamic quenching procedure. Thermodynamic parameters ΔH^Θ = −13.38 kJ mol⁻¹, ΔS^Θ = 66.73 J mol⁻¹ K⁻¹ were calculated based on the binding constant. These suggested that the binding reaction was enthalpy and entropy driven, and the electrostatic interaction played major role in stabilizing the reversible complex. The binding distance r = 5.5 nm between HSA and B12 was obtained according to Förster theory of energy transfer. The effect of B12 on the conformation of HSA was analyzed by synchronous fluorescence and CD spectroscopy. Synchronous spectra indicated that the polarity around the tryptophan (Trp214) residues of HSA was decreased and its hydrophobicity was increased; however, the α-helix content of the protein was predominant in the secondary structure but the CD spectra indicated that B12 induced minor conformational changes of HSA.     

醋酸艾塞那肽在Wistar大鼠体内的药物代谢动力学研究

研究醋酸艾塞那肽（exendin-4）在Wistar大鼠体内的药物代谢动力学，组织分布以及排泄特征。IODOGEN（四氯二苯基苷脲）法制备^125I-exendin-4，大鼠皮下或静脉注射，^125I-exendin-4，以放射性核素示踪动力法检测血液中的药物浓度，由非房室模型评价药物动力学参数。同时研究了大鼠皮下注射^125I-exendin-4后的组织分布和排泄。大鼠皮下注射^125I-exendin-4后Tmax和t1/2分别是（0．25±0．02）h和（1．28±0．14）h，绝对生物利用度为（65．5±10．2）％；^125I-exendin-4的分布快速而广泛，其中以肾脏中最高，而在脑组织中只有微量^125I-exendin-4；^125I-exendin-4主要随尿液排泄。实验结果与国外公布的实验数据基本一致。醋酸艾塞那肽在大鼠中的药物代谢动力学参数为临床试验提供了科学依据。     

NIR药品快速检测系统查出一例劣药的情况分析

通过NIR药品快速检测系统查出盐酸洛哌丁胺胶囊掺入诺氟沙星的情况分析，提示药品检测车车载技术人员在NIR药品快速检测系统使用过程中，要注重对检测结果的综合分析，对筛选未通过品种应进行全面检验，从中发现劣药，从而促进NIR药品快速检测系统以查假为主到查假治劣并重的转变，更大限度的发挥该技术高科技打假治劣的优势，提高药品检测车运转效能。     

杀微生物避孕凝胶剂的抗生育和抗菌作用研究

目的:观察杀微生物避孕凝胶剂的体外杀精、家兔抗生育和抗菌作用。方法:杀精试验采用改良的Sander-Crammer方法;家兔抗生育试验将家兔随机分为高、中、低3个剂量组,分别阴道给予凝胶剂48mg/kg,24mg/kg和12mg/kg,给药后10min与雄兔进行交配,21d后解剖并计算避孕率;抗菌实验用体外试管法观察凝胶剂的抗金黄色葡萄球菌、大肠埃希菌和白色念珠菌的作用。结果:在20s内最低体外杀精浓度为0.5mg/ml;3个剂量组家兔避孕率分别为100%、80%和20%;对金黄色葡萄球菌、大肠埃希菌和白色念珠菌的最低杀菌浓度分别为0.05625%、0.225%和0.45%。结论:研制的凝胶剂有明显的抗生育作用和抗上述3种致病菌作用。     

HPLC法测定蜂胶中阿替匹林的含量

建立蜂胶中抗肿瘤成分阿替匹林的含量测定方法.采用XDB-C18色谱柱;以甲醇-5 %乙酸为流动相梯度洗脱;流速1.0mL·in-1;检测波长280nm.阿替匹林在0.66～6.60μg范围内呈良好的线性关系(r=0.9997),平均回收率为99.71%,RSD为2.15%(n=6).本方法结果准确高,重复性好,可作为蜂胶的质量评价依据.     

Edible safety requirements and assessment standards for agricultural genetically modified organisms.

This paper describes the background, principles, concepts and methods of framing the technical regulation for edible safety requirement and assessment of agricultural genetically modified organisms (agri-GMOs) for Shenzhen Special Economic Zone in the People's Republic of China. It provides a set of systematic criteria for edible safety requirements and the assessment process for agri-GMOs. First, focusing on the degree of risk and impact of different agri-GMOs, we developed hazard grades for toxicity, allergenicity, anti-nutrition effects, and unintended effects and standards for the impact type of genetic manipulation. Second, for assessing edible safety, we developed indexes and standards for different hazard grades of recipient organisms, for the influence of types of genetic manipulation and hazard grades of agri-GMOs. To evaluate the applicability of these criteria and their congruency with other safety assessment systems for GMOs applied by related organizations all over the world, we selected some agri-GMOs (soybean, maize, potato, capsicum and yeast) as cases to put through our new assessment system, and compared our results with the previous assessments. It turned out that the result of each of the cases was congruent with the original assessment.     

Antioxidant, anti-semicarbazide-sensitive amine oxidase, and anti-hypertensive activities of geraniin isolated from Phyllanthus urinaria

The wrinkle-fruited leaf flower (Phyllanthus urinaria L.) (Euphorbiaceae) is widely used as a traditional folk medicine for inflammatory relief. Geraniin, the hydrolysable tannin, was purified by a series of chromatographic processes from the 70% aqueous acetone extracts of P. urinaria and identified by NMR [1H (500 MHz) and 13C NMR (126 MHz)] spectra and mass spectroscopy. The scavenging activities of geraniin against DPPH radicals (half-inhibition concentration, IC50, were 0.92 and 1.27 microM, respectively, for pH 4.5 and pH 7.9), hydroxyl radicals (IC50 was 0.11 microM by deoxyribose method and 1.44 microM by electron spin resonance method), and superoxide radicals (IC50 were 2.65 microM) were determined in comparison with positive controls. The inhibitory activities against xanthine oxidase (IC50 were 30.49 microM) were measured. Geraniin also showed dose-dependent inhibitory activities against semicarbazide-sensitive amine oxidase (SSAO, IC50 were 6.58 microM) and against angiotensin converting enzyme (ACE, IC50 were 13.22microM). For kinetic property determinations, geraniin showed competitive inhibitions against SSAO (the apparent inhibition constant, Ki, was 0.70microM) and mixed noncompetitive inhibitions against ACE. Spontaneously hypertensive rats (SHR, 10-week age) were orally administered to once (5 mg geraniin/kg SHR), and changes of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured over 24 h and compared with the positive control of captopril (2 mg/kg SHR). The geraniin showed antihypertensive activity in lowering SBP and DBP and showed a significant difference from the blank (distilled water) at 2, 4, 6, 8, and 24 h. Healthy food products could use geraniin for antioxidant protection and therapeutic effects in the future.     

深圳市“降消”项目健康教育与健康促进效果评价

目的评价深圳市“降低孕产妇死亡率、消除新生儿破伤风”项目健康教育与健康促进的效果,更好地为政府及相关部门制定相关政策提供依据。方法通过干预前后流动育龄妇女问卷调查及常住人口中干预组孕妇与对照组孕妇比较,评价健康教育效果。结果实施健康教育后,流动孕产妇孕产期保健知识知晓率与实施前相比明显提高(P<0.05),教育前后存在显著性差异;孕妇及家属妇幼保健知识培训后相关知识的正确率明显提高,20项保健知识中有19项(P<0.05)与对照组相比存在显著性差异;与2000年底相比,2006年底全市常住人口(户籍和暂住)孕产妇死亡率下降了一半;全人口孕产妇死亡率下降了2/3;新生儿破伤风发病率(全人口)下降了163%。全市户籍人口孕产妇率及新生儿破伤风发病率已连续3年为“0”。结论深圳市“降消”项目中实施健康教育与健康促进,可有效地提高育龄妇女的自我保健意识,对降低孕产妇死亡率和消除新生儿破伤风有着不可替代的作用。     

纳洛酮用于感染性休克患者时对肾脏功能的影响

目的:分析纳洛酮用于治疗感染性休克时对患者肾脏功能的影响。方法:选择ICU感染性休克患者43例,其中21例在治疗过程中使用了纳洛酮,为A组;另22例为按照病情相近、病因相同、年龄相仿的原则选取的未使用纳洛酮者作为对照,为B组。分析比较两组患者肾功相关指标的变化。结果:治疗前,所有患者均有少尿,尿白蛋白、尿β2-微球蛋白定量及血尿素氮和肌酐水平均明显高于正常,但两组之间比较均无显著性差异;经过治疗,所有患者的尿量、血尿素氮和肌酐水平均恢复到正常水平,而尿白蛋白、尿β2-微球蛋白定量明显下降,以A组患者的下降更为显著。结论:纳洛酮用于感染性休克患者时,对肾脏功能有一定的保护作用。     

DICOM图像处理与网络传输方法探讨

目的研究WINDOWS环境下DICOM图像处理和网络传输方法。方法利用免费开发工具DCMTK,采用VC 6.0进行二次开发,以动态链接库和OCX控件的形式实现DICOM图像的处理和网络传输。结果利用DCMTK开发动态链接库和OCX控件,利用它们编制应用程序,成功地实现了在WINDOWS环境下DICOM图像的处理。结论本研究采用DCMTK进行开发,实现了DICOM图像的处理和网络传输。