水飞蓟素对伴刀豆球蛋白A致免疫性肝损伤小鼠的保护作用

目的研究水飞蓟素对伴刀豆球蛋白A(concanavalin A,Con A)诱导的免疫性肝损伤小鼠的保护作用,探讨其可能的肝保护机制。方法将实验小鼠30只随机分为对照组、模型组、水飞蓟素组(200 mg·kg~(-1)),各10只。对照组和模型组小鼠按10 m L·kg~(-1)灌胃0.5%羧甲基纤维素钠(CMC-Na)水溶液,水飞蓟素组小鼠灌胃同等容量的水飞蓟素(200 mg·kg~(-1),0.5%CMC-Na混悬),每日1次,共10 d。实验末期,模型组和水飞蓟素组小鼠尾静脉注射Con A(15 mg·kg~(-1))建立小鼠免疫性肝损伤模型,检测小鼠血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、碱性磷酸酶(ALP)活性及肝组织超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、还原型谷胱甘肽(GSH)、丙二醛(MDA)含量;苏木精-伊红(HE)染色法观察肝组织病理学变化。ELISA法检测血清中肿瘤坏死因子-α(TNF-α)、白细胞介素-4(IL-4)和白细胞介素-6(IL-6)含量。结果水飞蓟素明显降低Con A所致免疫性肝损伤小鼠血清ALT、AST和ALP水平(P<0.01),还可增加肝组织SOD、CAT、GSH的活性,降低肝组织MDA水平(P<0.05或P<0.01),明显改善肝脏病理组织状况;显著降低小鼠血清TNF-α、IL-4和IL-6含量(P<0.01)。结论水飞蓟素能明显减轻Con A诱导的小鼠免疫性肝损伤,该作用与其增加肝组织中抗氧化酶的活性、降低脂质过氧化水平、降低TNF-α、IL-4和IL-6等促炎因子水平有关。     

伴刀豆球蛋白A，核糖和腺嘌呤协同促进缺血后心功能不全的恢复

急性缺血后心功能不全可能与细胞膜损害及高能化合物的合成障碍有关。用Ｗｉｓｔａｒ大鼠进行离体心脏灌注，３０ｍｉｎ全心缺血和３０ｍｉｎ再灌注导致心肌收缩力显著下降，细胞内钙含量升高和肌酸激酶漏出。用核糖（１ｍｍｏｌ·Ｌ１）和腺嘌呤（１ｍｍｏｌ·Ｌ１）进行再灌注，上述各项指标均无改善。用伴刀豆球蛋白Ａ（４０ｍｇ·Ｌ１）进行再灌汁，细胞内钙负荷减轻，肌酸激酶漏出减少，同时心肌收缩力增加，但ＡＴＰ含量无改善，用核糖，腺嘌呤和伴刀豆球蛋白Ａ联合进行再灌注，不但心肌收缩力显著升高，细胞内钙负荷减轻，肌酸激酶漏出减少，而且高能磷酸化合物含量显著恢复。实验表明，ＡＴＰ前体不能在短时间内使急性缺血后心功能不全恢复，但在伴刀豆球蛋白Ａ的协同作用下，能快速地恢复心肌收缩力和ＡＴＰ含量。     

蒿鳖养阴软坚方对刀豆球蛋白A诱导的肝纤维化的预防作用研究

目的:研究蒿鳖养阴软坚方对刀豆蛋白A(ConA)诱导的肝纤维化的预防作用。方法:将Balb/c小鼠随机分为7组,即正常、模型、复方鳖甲软肝片、秋水仙碱和蒿鳖养阴软坚方高、中、低剂量组。除正常组外,其余各组采用ConA15mg·kg-1尾静脉注射,每周1次,连续10周,复制小鼠肝纤维化模型,给药结束后观察各组小鼠的肝组织病理学变化,检测肝组织羟脯氨酸含量,并检测血清玻璃酸(HA)和Ⅲ型前胶原(PCⅢ)的含量。结果:模型组肝组织见大量炎症细胞浸润,肝细胞呈点、灶状和大片状坏死,汇管区、中央静脉周围及血窦内胶原纤维增生,肝纤维化程度分期及计分皆显著增高(P<0.01);与模型组比较,各给药组能不同程度地降低肝组织胶原蛋白含量,显著减轻肝纤维化程度(P<0.05),在降低胶原蛋白含量方面以1.16g·kg-1蒿鳖养阴软坚方和复方鳖甲软肝片的作用显著(P<0.05),而11.58g·kg-1蒿鳖养阴软坚方降低HA的作用较强。结论:蒿鳖养阴软坚方具有预防ConA诱导的小鼠肝纤维化的作用。     

芍药苷对伴刀豆球蛋白诱导的小鼠急性肝损伤的保护作用

目的 探究芍药苷在伴刀豆球蛋白（Con A）诱导的小鼠急性肝损伤中的作用。方法 通过尾静脉注射20 mg·kg^-1的ConA得到小鼠急性肝损伤模型。将小鼠随机分成空白组、模型组、低剂量实验组、高剂量实验组。低剂量实验组、高剂量实验组每日灌胃40和100 mg·kg^-1芍药苷,连续7 d;空白组、模型组在相同时间点给予等量生理盐水灌胃。最后1次灌胃后模型组、低剂量实验组、高剂量实验组均进行造模处理。以全自动生化分析仪检测血清谷丙转氨酶（GPT）、谷草转氨酶（GOT）和碱性磷酸酶（ALP）活力;以酶联免疫吸附测定法检测血清中肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）水平;用蛋白质印迹法检测丝裂原活化蛋白激酶（MAPK）、磷酸化的丝裂原活化蛋白激酶（p-MAPK3）、信号转导和转录激活因子（STAT3）、磷酸化的信号转导和转录激活因子3（p-STAT3）蛋白表达情况。结果 空白组、模型组、低剂量实验组、高剂量实验组的GPT活力分别为（40.56±3.36）,（201.48±5.05）,（157.16±7.71）和（141.95±3....     

pH敏感型原位凝胶的研究进展

pH敏感型原位凝胶随pH的变化而发生胶凝反应,缓慢持久地释放药物,可提高药物的生物利用度,是一种很有开发价值的新型药物传递系统。     

温度敏感原位凝胶在眼部给药系统中的研究进展

温度敏感原位凝胶可随温度变化发生凝胶反应,从而缓慢持久地释放药物,提高药物的生物利用度,是一种很有开发价值的新型药物传递系统.本文主要对温度敏感原位凝胶中聚合物的种类及应用,以及该剂型在眼部给药系统中的应用进行了综述.     

葡萄糖敏感型胰岛素递药系统研究进展

摘要：糖尿病是严重的全球性健康问题之一,皮下注射胰岛素是糖尿病的主要药物治疗手段,不仅给药不便且造成患者痛苦,此外,皮下注射胰岛素还有引起低血糖症的潜在风险。控释递药系统通过优化药物释放行为和改善药物体内动力学来提高治疗效率和安全性。葡萄糖敏感的智能型胰岛素递送系统引起了很大的关注。本文讨论了基于葡萄糖氧化酶、刀豆蛋白A和苯硼酸的葡萄糖敏感型胰岛素递送系统的最新研究进展,并对该领域的发展前景进行了展望。     

原位凝胶应用于眼部给药系统的研究进展

介绍原位凝胶在眼部给药系统中的研究新方法和新进展,以及原位凝胶的不同胶凝机理,分析胶化过程和眼部应用时的影响因素。原位凝胶滴眼剂可以显著延长药物释放,提高药物生物利用度。原位凝胶滴眼剂作为一种新型眼部药物新剂型,具有良好的应用前景。     

环孢素A眼用pH敏感型乳剂凝胶的角膜滞留性及药效学

目的:制备环孢素A眼用pH敏感型乳剂凝胶并研究其角膜滞留性及药效学。方法:以家兔为模型动物,环孢素A眼用乳剂为对照组,利用γ-闪烁扫描技术考察环孢素A眼用pH敏感型乳剂凝胶的眼部滞留性;并建立干眼症模型,以泪液分泌实验(schirmer I test,SIT)和角膜荧光素染色(fluorescence integral,FI)值为指标,结合外观评价,考察环孢素A眼用pH敏感型乳剂凝胶治疗干眼症的效果。结果:环孢素A眼用pH敏感型乳剂凝胶与对照组相比,显著延长在角膜的滞留时间;利用SPSS 19.0统计分析软件显示:实验组与阳性对照组在增加SIT值方面有极显著性差异(P<0.01),在降低FI值方面有显著性差异(P<0.05)。结论:环孢素A眼用p H敏感型乳剂凝胶显著延长在角膜的滞留时间,对干眼病的治疗起效更快,治疗效果更好。     

Glucose-sensitive gel rheology of dextran-concanavalin A mixtures suitable for self-regulating insulin delivery

Aqueous concentrated plain mixtures of dextran and concanavalin A (con A) were examined for their rheological response to glucose for comparison with previously studied partially photopolymerized acrylic derivatives. Non-destructive oscillatory tests were undertaken within the linear viscoelastic range to examine the relationship between the rheometry and the stoichiometry of the interactive materials and to examine rheological parameters as affected by molecular weight, component ratio, temperature and glucose concentrations between 0 and 1% w/w. These simple formulations were studied at 1 and 10 Hz at 0.5% strain at both 20 and 37°C. A second simplified rheological test was undertaken to demonstrate gel-sol reversibility and to produce a measure of equilibria created between these gels and glucose solutions with which they are in contact. This mimics the conditions in which the gel acts as a responsive gateway in the insulin delivery device. It proved that the gels equilibrate with glucose solutions, rather than indiscriminately removing glucose. This is important in terms of producing a delivery device that can respond in a reversible, glucose concentration-dependent manner. The method used for this is capable of relative values only but provides information not obtainable from conventional rheometry.     

Effects of CuCl2 on the dimer-tetramer equilibrium of concanavalin A

Tetrameric concanavalin A at neutral pH dissociated into the dimer when CuCl₂ was added in a concentration range comparable to protomer concentration. This effect of CuCl₂ was largely suppressed when NaCl concentration was increased. Neither the conformation of the protein nor its binding activity to 4-methylumbelliferyl α-D-man-nopyranoside was affected on addition of CuCl₂.     

Denaturation of concanavalin A by urea at acid pH

The denaturation of dimeric concanavalin A induced by urea at pH 3 has been studied using optical activity and sedimentation velocity. Under the conditions employed Mn⁺² and Ca⁺² are dissociated from the protein, but the basic structural elements are little changed from those prevailing in the functional lectin at pH 5.5 [H.E. Auer and T. Schilz, preceding paper in this issue]. The protein passes through three stages as the urea concentration is varied from 0 to 10 M. Below 4M urea the only effect observed is the loss of optical activity of the aromatic amino acid residues. At 4 M, a conformational change occurs producing extensive aggregation, which persists to 7 M. At 8–10 M urea a disordered monomeric protein molecule prevails. The protein could be reactivated provided that dilution to native conditions was very rapid and the protein concentration remained very low. Kinetics of denaturation were monitored by optical activity at 218, 225 and 283 nm, Transients with one, two or three components were observed, which were resolved by nonlinear regression according to sequential first-order decay laws. First order character was confirmed by independence of the kinetic parameters from protein concentration over a two- to four-fold range. Enthalpies and entropies of activation for the various steps were also determined. The transients at the three wavelengths monitor changes in β structure, β turns and aromatic groups, respectively. The urea dependence of the rate constants is unique in most cases. It is concluded that different structural elements of the concanavalin A molecule unfold independently from one another.     

双环醇对刀豆蛋白A引起肝损伤小鼠肝脏基因表达谱的影响

本实验研究双环醇对刀豆蛋白A(concanavalin A，Con A)静脉注射引起免疫性肝损伤小鼠肝脏基因表达谱变化的影响，探讨双环醇肝保护作用的分子机制。小鼠于注射Con A 26.5 mg·kg^-1前24、 8及1 h分别口服双环醇250 mg·kg^-1。测定血清丙氨酸转氨酶(alanine aminotransferase，ALT)及天冬氨酸转氨酶(aspartate aminotransferase，AST)水平，提取小鼠肝脏总RNA，经反转录用Cy3-dUTP和Cy5-dUTP分别标记制备cDNA探针。将cDNA探针与BiostarM-40S小鼠基因表达谱芯片进行杂交，经ScanArray 4000扫描仪扫描芯片并用GenePix Pro 3.0软件进行分析。双环醇可显著抑制刀豆蛋白A引起的血清ALT和AST升高。与刀豆蛋白A对照组相比，双环醇给药组有287条基因发生差异表达，占芯片基因总数的7.00%。其中166条基因表达量明显下调，121条基因表达量明显上调。表达变化的基因主要涉及代谢与细胞色素P450、应激与炎症凋亡、细胞周期调控、信号传导以及再生等相关功能。双环醇对刀豆蛋白A引起小鼠肝损伤肝脏基因表达谱变化具有一定的影响，此结果对今后深入研究双环醇的肝脏保护作用特点和临床应用具有重要意义。     

Development of a reversible bienzymatic system in immunoenzymatic technique

The use of specific captors solubilized with a ligand on to proteic membranes together with an automatic-computerized system is proposed for the determination of various haptens or antigens in biological and industrial fluids by an enzyme-linked immunoassay test. Two enzymes are used in this technique: the first enzyme for linking reversibly the immunocomplex to the insoluble matrix, the substrate of this enzyme being immobilized on the matrix; the second (beta-d-glucose oxidase) for labelling the antigen. Its activity is measured by fixing the immunocomplex gelatin membrane on to a pO(2) sensor. After incubation of the antigen labelled with glucose oxidase and the free antigen with specific antibodies linked with the first enzyme in a pre-established concentration, the reaction medium is introduced inside the continuous flow cell. O(2) consumption due to the enzyme reaction is measured in actual time when the electrode is in contact with the glucose standard solution. The signal is correlated by an injection of urea solution. The signal is processed with an automated microcomputer system.     

Nicotinamide N-methyltransferase (NNMT) and 1-methylnicotinamide (MNA) in experimental hepatitis induced by concanavalin A in the mouse

Nicotinamide N-methyltransferase (NNMT), which converts nicotinamide (NA) to 1-methylnicotinamide (MNA), is up-regulated in the cirrhotic liver. Because MNA displays PGI₂-dependent anti-inflammatory effects, the up-regulation of NNMT may play a regulatory role in liver inflammation. In the present work, we analyzed changes in NNMT activity in the liver and concomitant changes in the concentration of endogenous MNA in plasma in T-cell dependent hepatitis induced by concanavalin A (ConA) in BALB/c mice. Furthermore, we tested whether exogenous MNA possessed a protective effect against ConA-induced hepatitis. Development of liver injury induced by ConA (10 mg/kg, iv) was characterized by measurements of plasma concentration of alanine aminotransaminase (ALT), inflammatory cytokines (IFNγ and TNFα) and by histopathological examination. ConA-induced hepatitis was characterized by an early activation of inflammatory cytokines (IFNγ; from below 0.05 ng/ml to 23.72 ± 8.80 ng/ml; TNFα; from 0.07 ± 0.01 ng/ml to 0.71 ± 0.12 ng/ml, 2 h after ConA), an elevation of ALT (from 40.65 ±3.2 U/l to 5,092.20 ± 1,129.05 U/l, 8 h after ConA) and by morphological signs of severe liver inflammation and injury (24 h after ConA). In mice injected with ConA, NNMT activity in the liver was up-regulated approximately 2-fold to 3-fold, 8–24 h after ConAinjection. The concentration of MNA and its metabolites (Met-2PY and Met-4PY) in plasma were elevated approximately 2-fold 8 h after ConA injection. Exogenous MNA (100 mg/kg, iv) diminished ConA-induced liver injury, and this effect was reversed by an antagonist of the prostacyclin receptor, RO 3244794 (10 mg/kg,po). In conclusion, the present study demonstrated that hepatic NNMT activity and MNA concentration in plasma significantly increased during the progression of ConA-induced hepatitis in mice. This response may play a hepatoprotective role compatible with the PGI2-releasing properties of MNA.     

Comparison of lectin fromPseudixus japonicus and concanavalin a on lymphocytes proliferation and cytotoxicity

Pseudixus japonicus agglutinin (PJA) was isolated. And its characteristics were compared with those of concanavalin A (Con A). PJA is a glycoprotein composed of 49.3% carbohydrate and 50.7% protein which had relatively high percentages of glutamic acid, aspartic acid and phenylalanine residues. The hemagglutinating activity of PJA was approximately one-eighth of that of Con A when tested with mouse erythrocytes. PJA failed to stimulate the proliferation or transformation of human and mouse lymphocytes in contrast to Con A. PJA and Con A showed cytotoxicities against SNU-1 (human stomach cancer cells), SNU-C1 (human colon cancer cells) and mouse Sarcoma 180 cells when tested by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay. The antitumor activity of the lectinin vivo was also tested in Sarcoma 180 bearing mice. There was no significant difference in prolongation of life span of the mice after the treatment with PJA and Con A for 10 consecutive days.     

Antitumor effects of concanavalin A and Sophora flavescens lectin in vitro and in vivo

Aim： Proteins with legume lectin domains are known to possess a wide range of biological functions. Here, the antitumor effects of two representative legume lectins, concanavalin A （ConA） and Sophora flavescens lectin （SFL）, on human breast carcinoma cells were investigated in vitro and in vivo. Methods： Human breast carcinoma MCF-7 cells and human normal mammary epithelial MCF-IOA cells were examined. Cell viability was detected using WST-1 and CCK-8 assays. Cell apoptosis was analyzed with Hoechst 33258 staining. Cell cycle was investigated using flow cytometry. The expression of relevant proteins was measured using Western blotting. Breast carcinoma MCF-7 bearing nude mice were used to study the antitumor effects in vivo. The mice were injected with ConA （40 mg/kg, ip） and SFL （55 mg/kg, ip） daily for 14 d. Results： ConA and SFL inhibited the growth of MCF-7 cells in dose- and time-dependent manners （ICso values were 15 and 20 pg/mL, respectively）. Both ConA and SFL induced apoptotic morphology in MCF-7 cells without affecting MCF-IOA cells. ConA and SFL dose- dependently increased the sub-G1 proportion in MCF-7 cells, while SFL also trip=~ered the G2/M phase cell cycle arrest. Both ConA and SFL dose-dependently increased the activities of caspase-3 and caspase-9 and release of cytochrome c from mitochondria into cytoplasm, up-regulated Bax and Bid, and down-regulated Bcl-2 and BcI-XL in MCF-7 cells. ConA reduced NF-KB, ERK, and JNK levels, and increased p53 and p21 levels, while SFL caused similar changes in NF-KB, ERK, p53, and p21 levels, but did not affect JNK expression. Administration of ConA and SFL significantly decreased the subcutaneous tumor mass volume and weight in MCF-7 bearing nude mice. Conclusion： ConA and SFL exert anti-tumor actions against human breast carcinoma MCF-7 cells both in vitro and in vivo.