胰岛素的色谱分析方法

随着糖尿病的发病率不断攀升,有必要建立简单易行的胰岛素的分析方法。胰岛素制剂的纯度检验,胰岛素生产及纯化过程的监控,生物体液及胰岛细胞分泌胰岛素的状况,重组胰岛素结构的测定及活性研究等都离不开胰岛素的测定。而胰岛素的色谱分析是一个年轻的领域。本文按照体内外样品、检测方法和样品制备总结了近年胰岛素的色谱分析方法。     

细胞分裂素检测方法的研究进展

细胞分裂素是一类重要的植物生长调节激素,对这类激素进行超微定量检测对于揭示其在植物体内的信号转导机理、发挥其对作物生长的调控作用具有重要意义.本文综述了近年来细胞分裂素各种分析方法的研究进展,包括免疫分析法、气相色谱法、高效液相色谱法、毛细管电泳法和电化学方法等,介绍了实际样品常用的前处理方法,并讨论了未来的研究发展方向.     

常见鼠药中毒及检测技术研究进展

鼠药是控制有害啮齿类动物最经济有效的方式,而大多数鼠药对人畜均具有较强的毒性。鼠药的不合理使用严重威胁人类和其他非靶标动物的生命安全。由误食、二次中毒、自杀及恶意投毒等原因导致的中毒事件时有发生。发展快速准确的鼠药中毒检测技术对于及时确定中毒靶标从而进行有效干预、对症治疗是降低鼠药危害的重要手段。常规的鼠药检测大多基于液相色谱-串联质谱等仪器分析方法。近年来,免疫分析技术由于具有操作简单、快速的优点,开始用于鼠药的快速检测。该文重点针对典型的氟乙酰胺、毒鼠强和抗凝血类鼠药的中毒概况和检测技术进行了总结,以期为相关领域研究人员提供技术指导。     

氨基酸膦酸氧钒配合物的降糖活性及与DNA作用研究

研究证明钒无论体内还是体外都具有良好的降糖活性。对于胰岛素强化剂进行糖尿病的介入性治疗来说，钒配位化合物的设计合成、基团的选择、协同效应等均具有重要的意义。为了研究钒配位化合物胰岛素强化剂的活性，通过链脲霉素模型鼠进行了口服生物学实验，结果表明氨基酸膦酸氧钒配合物具有较高的体内降糖活性。通过琼脂糖凝胶电泳研究表明氨基酸膦酸氧钒配合物与DNA之间存在较强的相互作用。     

钒化合物抗糖尿病作用的研究进展*

在糖尿病的治疗研究中,体内和体外的研究表明,钒化合物可以降低I型和II型糖尿病血糖,促进葡萄糖转运和糖原合成,具有“类胰岛素作用”。本文综述了近年来钒化合物在降低和改善糖尿病症状的生物效应及其通过胰岛素信号通路在降糖作用的分子机制的研究进展。     

微量元素与激素

微量元素可以在激素的分泌、活性以及与组织的结合等各个环节上影响激素。例如，锌与生长激素相结合，可使之更稳定，不易失活。体内锌态势的改变可影响胰岛素的合成、分泌、贮藏和活力，锌与胰岛素蛋白质结合形成一种复合物，可延长胰岛素的作用时间，锌与性激素的关系也十分密切。锌促进睾丸酮的合成分泌。     

钒化合物可能用于治疗糖尿病

英国哥伦比亚大学的John H.McNeiu等人发现了一种在糖尿病治疗上有广泛前景的钒化合物。糖尿病是一种体内血糖浓度高出正常范围的威胁生命的一种疾病。人们通常用胰岛素来治疗这种疾病。然而,由于胰岛素易被消化系统破坏,所以不适宜口服,而只能靠注射进入人体内。由于在注射上存在的一些困难,研究人员一直在寻找一种与胰岛素同效的适于口服的药品。     

胰岛素介体的功能——调节细胞的cAMP和脂肪合成及糖尿病的影响

本文报道用猪、小白鼠和大白鼠肝细胞质膜与胰岛素(100—150μU/ml)保温后,从膜至少释放两种胰岛素介体(Insulin mediator或Insulin chemical mediator),即组份1和组份3。它们能抑制脂解激素和福司可林(Forskolin)所刺激的脂肪细胞的cAMP形成及促进细胞的脂肪合成。组份1的分子量约为3700—4000,组份3约1000—1500dalton。组份1胰岛素介体为本文第一次报道的新发现的化合物。糖尿病小白鼠或大白鼠的肝细胞膜产生此种介体比正常动物的明显下降,但经体内注射胰岛素治疗后,则介体的释放可恢复正常。     

压电胰岛素-C肽微阵列免疫传感器研究

以AT切型、基频10MHz的镀金膜石英晶体作为换能器,将抗人胰岛素和C肽单克隆抗体固定在石英晶体电极表面,用2×5检测池固定夹具构建一种新型压电胰岛素-C肽微阵列免疫传感器.研究了抗体固定方法、抗体工作浓度、固定量、一致性以及传感器的响应参数如检测温度、时间和特异性等的影响.该微阵列传感器在胰岛素浓度为2.5～160.0mIU/L、C肽浓度为0.375～12.0ng/mL范围内响应特性良好,压电晶体频率偏移值与胰岛素和C肽浓度呈良好的线性关系.将此微阵列传感器用于人血清标本的测定,结果与放射免疫法符合(r为0.92和0.94).此微阵列传感器具有灵敏度高、特异性好,低密度阵列结构,检测通量较高,不需标记,操作简单、能实时在线检测和重复使用等优点,能用于临床实验诊断,具有临床推广应用价值.     

PPARγ激动剂的设计、合成及其胰岛素增敏活性

糖尿病是由于体内胰岛素分泌不足或者胰岛素抵抗引起的以高血糖和糖尿为特征的内分泌代谢疾病,现在已经成为仅次于心血管疾病和癌症的第三大危害人类健康的疾病.据世界糖尿病组织统计,现在全球有确诊糖尿病患者1.94亿,预计至2005年这个数字将达到3.33亿.中国现有5000万患者,其中Ⅰ型只占1%,90%以上为Ⅱ型.     

壳聚糖及其在分析化学中的应用

综述了壳聚糖、甲壳素在污水处理、电化学、原子吸收光谱、高效液相色谱、吸光光度法中的应用。引用文献28篇。     

煤烘玉米和饮水为介质地氟病区骨畸形病人全血尿多元素含量的分析

采集了贵族个煤烘玉米为主要介质和河北２个饮水为介质氟病区内骨畸形病人的全血、尿、检测了其中８种元素含量,结果表明,贵州各氟病区少儿骨软化与成年骨硬化畸形病人的全血铝、钙、磷、铁和尿氟、铝均显著高于同龄对照组,尿磷均低于同龄对照组。少儿骨软化病人全血锌均下降,尿锌多下降。某水型氟病区骨软化经产妇尿氟、全血铜升高;骨软化少年全血铝显著升高,锌、铁下降,尿氟升高,尿锌,磷下降。海边的典型氟骨症病人全血、     

Radial structure and property relationship in the thermal stabilization of PAN precursor fibres

Here we report on the role of oxygen in the evolution of radial heterogeneity in the fibre structure and properties of PAN fibres stabilized in air and vacuum at different temperatures. Modulus mapping by Nano-indentation showed heterogeneous modulus distribution in the fibres treated in air, while no variation in modulus was observed in fibres processed in vacuum. Raman spectroscopy and elemental analysis revealed that the temperature dependent oxygen diffusion from skin to core of the fibres assisted in the evolution of higher extent of sp²-hybridized carbons in the skin compared to core of the air treated samples. Conversely, no radial structure variations were observed in the vacuum treated fibres. Higher modulus in the skin of air-treated fibres was due to the formation of compact structures which was associated with the enhanced intermolecular interactions facilitated by the formation of C=C bonds within the polymer backbone, promoted by oxidative-dehydrogenation reaction. Supporting these observations, the fracture morphology examined by SEM showed a brittle fracture in the skin and ductile fracture in the core.     

VISCOMETRIC INVESTIGATIONS OF POLYVINYLPYRROLIDONE IN MIXED SOLVENTS AND WITH VARYING TEMPERATURE

The viscosity behavior of polyvinylpyrrolidone (PVP) has been determined at 25℃ in mixed solvents comprising water/dimethylformamide (DMF) and water /methanol (MeOH). Analysis of the data has considered the PVP as being both host and guest polymer in solution. The intrinsic viscosity of PVP in DMF is higher than in water and in MeOH, but also increases in a mixed solvent with high water content because of the effect of polymer-solvent interactions. It was also found that the intrinsic viscosity of PVP at finite concentration, [ηpvp]c decreases with an increase in the concentration of PVP in solution. The viscosity behavior of PVP in a mixed solvent is affected by the concentration-dependent intermolecular excluded volume effect, which can be quantitatively expressed by the parameter, bY, which reflects the shrinkage of PVP chain coils, resulting in a decrease of [ηpvp]c. The effect of temperature on the viscosity behavior of PVP in MeOH shows that the interaction parameter increases up to a maximum value, and then decreases after a certain temperature.     

Precision-cut liver slices from rats of different ages: basal cytochrome P450-dependent monooxygenase activities and inducibility

The biotransformation capacity – of the cytochrome P450 (CYP) system for example – is lower but inducibility is more pronounced in neonates than in adults. On the other hand, both enzyme activities and inducibility decline with senescence. Precision-cut rat liver slices are widely used as an in vitro tool for the examination of drug toxicity, xenobiotic metabolism or enzyme induction. The aim of the present study was to assess whether age-related changes in CYP activities and induction observed in vivo are also mirrored in vitro in liver slices. For this purpose, different CYP model reactions were measured in precision-cut liver slices from one-day-old, 40-day-old and one-year-old rats after in vitro exposure to various inducers. Similar to the in vivo situation, basal CYP activities were distinctly lower and inducibility was much more pronounced in liver slices from neonatal than in those from adult animals. Also, enzyme activities were mostly somewhat lower in liver slices from aged rats compared to those from 40-day-old rats. However, CYP inducibility was less pronounced than with younger animals too. Thus, precision-cut rat liver slices are a suitable in vitro tool for investigating age-related changes in CYP activities and induction as well as developmental differences in drug metabolism and toxicity.     

Alteration in photosystem II photochemistry of thylakoids isolated from senescing leaves of wheat seedlings

Wheat seedlings, grown for 7 days in the light, were allowed to senesce in the light or dark, and the change in the photosystem II (PS II) photochemistry of chloroplasts isolated from the primary leaves of these seedlings was investigated. The decrease in oxygen evolution and the fast fluorescence results indicated that the impairment of PS II in the leaves of seedlings senescing in the light was different from that in the leaves of seedlings senescing in the dark. Thermoluminescence studies showed a structural modification in the Q_B protein of chloroplasts isolated from leaves senescing in the light and an alteration in the S state transition of chloroplasts isolated from leaves senescing in the dark.     

Determination of Penicillins in Milk by a Dual-Optrode Biosensor

Penicillins are the most frequently found antibiotic residues in milk, as they are commonly used for the treatment of bacterial infections in cows. In the present study, we introduce a method for the rapid detection of penicillin residues in raw milk based on the determination of glucose concentration in milk with a dual flow-through biosensor. The molar concentration of glucose in milk is typically over 500 times lower than the concentration of lactose and is highly dependent on the rate of lactose hydrolysis, which is catalyzed by β-galactosidase. Glucose concentrations in milk change with variation in the β-galactosidase activity. β-Galactosidase is an enzyme produced in the microbiota in milk and its activity is inhibited by benzylpenicillin. Spiking milk with benzylpenicillin lowers glucose concentrations in comparison to high-quality milk after short storage intervals. The presence of penicillin in the milk of treated animals resulted in decreased glucose concentrations in comparison with high-quality milk that contained no antibiotics. The glucose concentration in milk samples was followed by the system enabling the elimination of the effects of bacterial respiration in the output with reliable results in less than 1?min.     

Graves病患者经131I治疗后血浆和红细胞锌含量的变化及其临床意义

为研究Graves病(GD)患者经^131I治疗后血浆和红细胞锌(Zn)含量的变化及其临床意义，采用原子吸收分光光谱法(AAS)和放射免疫分析法(Rn)分别检测了40例GD患者、20例经^131I治疗后甲状腺功能恢复至正常水平GD患者与30名健康人血浆和红细胞Zn的含量以及血浆甲状腺激素水平。结果表明，GD组红细胞Zn含量明显低于对照组(P＜0．01)；血浆Zn含量虽略低于对照组，但无统计学意义(P＜0．05)；且Zn与FT4呈明显负相关(P＜0．01)、与TSH呈正相关(P＜0．05)。GD治疗缓解组红细胞Zn明显高于治疗前(P＜0．01)，血浆Zn明显低于治疗前(P＜0．05)；红细胞Zn检测GD的敏感性与特异性分别为95．0％与96．7％。提示GD患者存在红细胞Zn含量改变，甲状腺激素可能干扰红细胞Zn的代谢，同时测定红细胞Zn可作为GD的临床诊断、治疗以及疾病转归的参考指标。     

Fluid rheological effects on streaming dielectrophoresis in a post-array microchannel

Recent studies have demonstrated the strong influences of fluid rheological properties on insulator-based dielectrophoresis (iDEP) in single-constriction microchannels. However, it is yet to be understood how iDEP in non-Newtonian fluids depends on the geometry of insulating structures. We report in this work an experimental study of fluid rheological effects on streaming DEP in a post-array microchannel that presents multiple contractions and expansions. The iDEP focusing and trapping of particles in a viscoelastic polyethylene oxide solution are comparable to those in a Newtonian buffer, which is consistent with the observations in a single-constriction microchannel. Similarly, the insignificant iDEP effects in a shear-thinning xanthan gum solution also agree with those in the single-constriction channel except that gel-like structures are observed to only form in the post-array microchannel under large DC electric fields. In contrast, the iDEP effects in both viscoelastic and shear-thinning polyacrylamide solution are significantly weaker than in the single-constriction channel. Moreover, instabilities occur in the electroosmotic flow and appear to be only dependent on the DC electric field. These phenomena may be associated with the dynamics of polymers as they are electrokinetically advected around and through the posts.     

微波制样的应用

介绍了微波制样在分析化学中的应用，包括微波试样消解，微波加热水样测定CODcr，微波加热水解蛋白质测定各种氨基酸，以及微波萃取等。特别是对微波试样消解在应用中的一些问题，作了较详细的叙述。