一种新型尿酸氧化酶四聚体提取纯化方法的建立

目的 建立一种简便、快速的尿酸氧化酶四聚体提取纯化的方法,以适应大规模生产需求。方法 首先通过基因工程的方法获得可以稳定发酵生产尿酸氧化酶的大肠埃希菌菌株,再通过一步萃取法从破碎菌体沉淀中获得尿酸氧化酶蛋白混合物,通过硫酸铵沉淀、离子交换和分子筛层析,最终获得纯化的活性尿酸氧化酶四聚体。结果 通过优化发酵及提取条件,每升发酵液可得到尿酸氧化酶四聚体蛋白约400 mg,其纯度>95%,比活>10 U/mg。结论 建立了一种新的尿酸氧化酶四聚体高效提取纯化的方法。     

Natural compounds with xanthine oxidase inhibitory activity: A review

Hyperuricemia (HUA), a disease due to an elevation of body uric acid level and responsible for various diseases such as gout, cardiovascular disorders, and renal failure, is a major ground debate for the medical science these days. Considering the risk factors linked with allopathic drugs for the treatment of this disease, the debate has now become a special issue. Previously, we critically discussed the role of dietary polyphenols in the treatment of HUA. Besides dietary food plants, many researchers figure out the tremendous effects of medicinal plants‐derived phytochemicals against HUA. Keeping in mind all these aspects, we reviewed all possible managerial studies related to HUA through medicinal plants (isolated compounds). In the current review article, we comprehensively discussed various bioactive compounds, chemical structures, and structure–activity relationship with responsible key enzyme xanthine oxidase.     

舒洛地特通过抑制NOX4/NLRP3通路减轻高糖诱导的视网膜血管损伤

目的:观察舒洛地特(SDX)在糖尿病状态下对视网膜微血管内皮细胞的保护作用。方法:(1)采用高脂喂养及腹腔注射链脲佐菌素的方法构建C57BL/6小鼠的2型糖尿病模型,对小鼠腹腔注射SDX或等体积生理盐水治疗12周。用伊文思蓝法检测视网膜微血管渗漏及微血管密度改变;用Western blot、免疫荧光等方法检测各组小鼠视网膜中NLRP3炎症小体成分、紧密连接蛋白1(ZO-1)及NADPH氧化酶4(NOX4)的表达情况。(2)用高糖处理人视网膜微血管内皮细胞(HRMECs),并与梯度浓度的SDX共处理;用腺病毒感染HRMECs以过表达NOX4或者用siRNA转染HRMECs以敲减NOX4,观察NLRP3炎症小体成分、NOX4、ZO-1和VE-钙黏着蛋白(VE-Cad)的表达情况,以及活性氧簇(ROS)的生成情况。结果:(1)SDX处理增加糖尿病小鼠视网膜中ZO-1蛋白的表达,抑制糖尿病小鼠视网膜微血管渗漏,增加糖尿病小鼠视网膜微血管密度和节细胞数量,并抑制NLRP3炎症小体的活化(P<0.05)。(2)在高糖刺激的HRMECs中,SDX处理增加ZO-1和VE-Cad蛋白的表达,显著抑制NLRP3炎症小体活化及NOX4介导的ROS生成(P<0.05)。(3)沉默NOX4可降低高糖刺激下HRMECs的NLRP3炎症小体活化和ROS生成,并抑制高糖刺激诱导的ZO-1和VE-Cad表达下降(P<0.05)。(4)过表达NOX4可明显增加HRMECs中NLRP3炎症小体活化和ROS生成,降低ZO-1和VE-Cad蛋白的表达(P<0.05);过表达NOX4后再予以SDX处理能部分逆转SDX引起的以上改变(P<0.05)。结论:SDX通过抑制NOX4/ROS/NLRP3通路减轻高糖诱导的视网膜血管内皮损伤。     

NADH/NADPH Oxidase and Vascular Function

The vascular NADH/NADPH oxidase has been shown to be the major source of superoxide in the vessel wall. Recent work has provided insight into its structure and activity in vascular cells. This enzyme is involved in both vascular smooth muscle hypertrophy and in some forms of impaired endothelium-dependent relaxation. Because oxidative stress in general participates in the pathogenesis of hypertension and atherosclerosis, the enzymes that produce reactive oxygen species may be important determinants of the course of vascular disease. (Trends Cardiovasc Med 1997;7:301–307). © 1997, Elsevier Science Inc.     

Decreased Histamine Catabolism in the Colonic Mucosa of Patients with Colonic Adenoma

Introduction Alterations in mucosal histamine degradation play an important role in various gastrotinestinal diseases including colonic adenoma. In humans, histamine can be catabolized either by oxidative deamination by diamine oxidase (DAO) or by ring methylation by histamine N-methyltransferase (HNMT). The significance of HNMT in this context was investigated for the first time in this project. Methods About 94 colonic biopsies were endoscopically obtained from 23 patients suffering from colonic adenoma and 26 biopsies from six healthy individuals. Each sample was mechanically homogenized, homogenates were cleared by centrifugation and used for determination of protein and histamine concentrations and enzyme activities of DAO and HNMT by radiometric assay. Results In adenoma patients DAO activities were slightly and HNMT activities were significantly decreased in normal mucosa compared to controls. Activities of both enzymes were significantly lower in adenoma tissue than in healthy mucosa in the same patients. A significant correlation was found between HNMT and DAO in all investigated samples. Histamine concentrations were elevated in adenoma patients. Conclusions Histamine catabolism is decreased in the colonic mucosa of patients with colonic adenoma.     

球型脂联素对高糖环境NIT-1胰岛β细胞功能的影响

用β细胞株NIT-1来研究球型脂联素对高糖损伤β细胞分泌功能及相关基因表达的影响.结果 显爪球型脂联素可恢复部分β细胞功能相关基因的表达,抑制高糖诱导NAD(P)H氧化酶组分p47phox表达增加,但未能改善高糖诱导的胰岛素mRNA水平下降及胰岛素分泌缺陷.     

抗抑郁药的研究新进展

抑郁症正成为一个严重的全球问题。目前抗抑郁药物分四大类：单胺氧化酶抑制剂（Monoamine oxidase inhibitors,MAOIs）、三环类药物（Tricyclicantide pressants,TCAs）、选择性5-色胺再摄取抑制剂（Selective serotonin reuptake inhibitors,SSRIs）、新型抗抑郁药。     

Metabolism and physiologically based pharmacokinetic modeling of flumioxazin in pregnant animals

A physiologically based pharmacokinetic (PBPK) model was developed to predict the concentration of flumioxazin, in the blood and fetus of pregnant humans during a theoretical accidental intake (1000 mg/kg). The data on flumioxazin concentration in pregnant rats (30 mg/kg po) was used to develop the PBPK model in pregnant rats using physiological parameters and chemical specific parameters. The rat PBPK model developed was extrapolated to a human model. Liver microsomes of female rats and a mixed gender of humans were used for the in vitro metabolism study. To determine the % of flumioxazin absorbed after administration at a dose of 1000 mg/kg assuming maximum accidental intake, the biliary excretion study of [phenyl-U-¹⁴C]flumioxazin was conducted in bile duct-cannulated female rats (Crl:CD (SD)) to collect and analyze the bile, urine, feces, gastrointestinal tract, and residual carcass. The % of flumioxazin absorbed at a dose of 1000 mg/kg in rats was low (12.3%) by summing up ¹⁴C of the urine, bile, and residual carcass. The pregnant human model that was developed demonstrated that the maximum flumioxazin concentration in the blood and fetus of a pregnant human at a dose of 1000 mg/kg po was 0.86 μg/mL and 0.68 μg/mL, respectively, which is much lower than K_m (202.4 μg/mL). Because the metabolism was not saturated and the absorption rate was low at a dose of 1000 mg/kg, the calculated flumioxazin concentration in pregnant humans was thought to be relatively low, considering the flumioxazin concentration in pregnant rats at a dose of 30 mg/kg. For the safety assessment of flumioxazin, these results would be useful for further in vitro toxicology experiments.