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1.
Lipid peroxide (LPO) plays pivotal roles in the process and development of many diseases. In this work, we studied the inhibitory effect of probimane (Pro), a Chinese anticancer agent, on erythrocyte LPO and the interaction of Pro with sialic acids (sia). Malondialdehyde (MDA) of erythrocytes activated by hydrogen peroxide was measured. Pro was found to inhibit the product of LPO induced by hydrogen peroxide in a non-enzyme system of both rabbit and human erythrocytes in the absence of doxorubicin. Sia were  相似文献   

2.
Sialic acids (neuraminic cids)are a special series of 9-carbon ring negatively charged carbohydrates,which has been found to be selectively changed in malignant cells from structures(both synthesis and structure modifications)to functions(up and down regulation in cells),Sialic acids,in single forms or conjugates.have been systematically studied both in lab and in clinics by GC,GCMS,NMR,HPTLC,HPLC and other modern analytical means.Sialic acids and related conjugates are predicted to be used in cancer diagnosis,cancer prognostic forecasting,designing of cancer chemotherapy regimens,uncovering carcinogenetic processes and neoplasm metastasis.Tumor cell regulative system and pathways are correlated with sialic acids,which can be applied to prognostic evaluation of cancer patients,and antimetastatic chemotherapy by sialic acid derivatives and analogues,Searching for new biological characteristics of sialic acids in cells have also been extensively studied these days.In this paper,main stream discoveries and advancements are provided.also discussions of possible mechanisms and hypotheses are invoked.  相似文献   

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以L-天冬氨酸(ASP)为原料,制备了羧酸基聚天冬氨酸(PASP-ASP)。通过失重法及电化学法测定了羧酸基聚天冬氨酸的缓蚀能力,实验结果表明,随着羧酸基聚天冬氨酸用量的增加其缓蚀效果逐渐增强,之后趋于平缓;采用静态阻垢法测定了羧酸基聚天冬氨酸在不同浓度下对碳酸钙的阻垢能力,实验结果表明,随着羧酸基聚天冬氨酸用量的增加其阻垢效果也逐渐增强,在6 mg·L-1时阻垢率达到了98.88%。  相似文献   

5.

Objective  

Human embryonic stem cells (hESCs) have recently been reported as an unlimited source of mesenchymal stem cells (MSCs). The present study not only provides an identical and clinically compliant MSC source derived from hESCs (hESC-MSCs), but also describes the immunomodulative effects of hESC-MSCs in vitro and in vivo for a carbon tetrachloride (CCl4)-induced liver inflammation model.  相似文献   

6.
基于静态阻垢实验系统,研究了聚天冬氨酸的阻垢性能,探讨了钙离子浓度、时间、温度以及pH值对其阻垢性能的影响,通过红外光谱和热重分析对聚天冬氨酸进行表征,并在过冷沸腾传热装置中实验验证了聚天冬氨酸的抗垢性能。实验结果表明:聚天冬氨酸可耐高温、热稳定性好.可应用于高温水处理系统和高钙离子浓度水处理系统,适用于工业锅炉水处理及供暖水处理系统。  相似文献   

7.
INTRODUCTION Cell encapsulation in biocompatible and semipermeable polymeric membranes is an effective method for immunoprotection, regardless of the type of recipient (allograft, xenograft, etc.). The semipermeable nature of the membrane prevents high molecular weight molecules, antibodies and other immunologic moieties from coming into contact with the encapsulated cells and destroying them as foreign invaders, but permits the entry of nutrients and oxy- gen and the exit of therapeutic p…  相似文献   

8.
Objective: To prepare microencapsulated cells releasing human tissue inhibitor of metalloproteinase-2 (TIMP-2), and investigate their biological characteristics in vitro. Methods: Chinese hamster ovary (CHO) cells were stably transfected with a human TIMP-2 expression vector, encapsulated in barium alginate microcapsules and cultured in vitro. Morphological appearance of the microcapsules was observed under a light microscope. Cell viability was assessed using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Enzyme linked immunosorbent assay (ELISA) and reverse zymography were used to confirm the release of biologically active TIMP-2 from the microcapsules. Cryopreservation study of the microencapsulated cells was carried out using dimethyl sulfoxide (DMSO) as preservative agent. Results: The microcapsules appeared like a sphere with diameter of 300–600 μm. The surface of the capsule wall was clearly smooth. The microencapsulated cells survived well and kept proliferating over the 6 weeks observed. No significant difference in TIMP-2 secretion was found between encapsulated and unencapsulated cells. Reverse zymography confirmed the bioactivity of MMP (matrix metalloproteinase) inhibition of TIMP-2. The cryopreservation process did not damage the microcapsule morphology nor the viability of the cells inside. Conclusion: Microencapsulated engineered CHO cells survive at least 6 weeks after preparation in vitro, and secrete bioactive TIMP-2 freely from the microcapsules.  相似文献   

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As2O3纳米粒的制备、表征和体外治疗人肝癌细胞的研究   总被引:3,自引:0,他引:3  
研究了As2O3 纳米粒的制备方法、表征及其抗肝癌细胞的作用.采用溶胶凝胶法制备As2O3 纳米粒,并用透射电镜、能谱仪和图像分析仪等方法对其进行表征及特性检测.通过MTT法和流式细胞仪法研究了不同浓度As2O3 纳米粒对人肝癌细胞株的影响,并与传统的As2O3 溶液进行了比较.实验中制备了2种粒径大小的As2O3 纳米粒子,其平均直径分别为80nm和40nm,通过能谱仪的测试证实所制备的纳米粒为As2O3,且无其他成分.体外细胞实验发现,As2O3 纳米粒处理细胞48 h后,人肝癌细胞的存活率明显低于同浓度的As2O3 溶液处理组(P<0.05).研究结果显示,通过溶胶凝胶法可将As2O3 制备成纳米粒子;体外细胞实验表明,与传统的As2O3 溶液相比,As2O3纳米粒子可对肿瘤细胞产生更强细胞毒作用.  相似文献   

11.
采用索氏提取法分别从中草药柴胡和红花中提取了两种缓蚀剂,采用失重法和电化学法研究了两种缓蚀剂在0.1mol/L 盐酸介质中对碳钢缓蚀作用,比较了缓蚀剂不同浓度、温度和腐蚀浸泡时间等因素对碳钢缓蚀率的影响.结果表明,提取的两种缓蚀剂对碳钢都具有良好的缓蚀作用,从红花中提取的缓蚀剂缓蚀率为83.5%,极化曲线表明这两种缓蚀剂为混合抑制型缓蚀剂.  相似文献   

12.
研究了在可见光条件下,用实验室合成的Fe3+掺杂TiO2为催化剂催化降解酸性红染料,重点考察了Fe3+的掺杂量、Fe3+掺杂TiO2为催化剂的添加量、酸性红溶液的初始浓度、溶液pH值、光照时间对降解率的影响.实验结果表明,Fe3+掺杂比为1.5%、催化剂用量为1.5 g/L、pH为2.0、质量浓度为40 mg/L的酸性红100 mL,用白炽灯光照降解酸性红30 min,酸性红降解率可达98.45%.  相似文献   

13.
通过使用电子顺磁共振仪(ESR)对苯乙烯自由基聚合体系中自由基的跟踪测试,进一步证实12-钼磷酸确实能够在自由基聚合体系中起到阻聚剂的作用,而且更加明确地提出其阻聚机理:通过捕获体系中的电子达到抑制自由基聚合反应的发生.  相似文献   

14.
采用Tafel极化曲线法和电化学交流阻抗谱法测定不同浓度缓蚀剂在0.2 mol·L-1乙酸介质中对冷轧钢的缓蚀作用.结果表明:在20℃、0.2 mol·L-1乙酸溶液中二乙基二硫代氨基甲酸钠对冷轧钢具有较好的缓蚀效果,缓蚀率随着缓蚀剂浓度的增加而增大,当缓蚀剂的浓度为3×10-3 mol·L-1时,缓蚀率达到85%,属于阴极型缓蚀剂.二乙基二硫代氨基甲酸钠在冷轧钢表面的吸附符合Langmuir吸附等温式,其吸附为自发进行的物理和化学吸附.  相似文献   

15.
The aim of the present study is to analyze sperm membrane changes and the spermicidal effect in treatment with the crude extract from Polygala tenuifolia Willd (PTW) in vitro. The root of PTW was extracted in distilled water. Normal human spermatozoa were used to assess the spermicidal activity (Sander-Cramer assay) of the extract from the PTW root. The hypo-osmotic swelling (HOS) test and the eosin Y (EY) staining were used to detect the integrity of sperm membrane and vitality. The sperm chromatin dispersion (SCD) test was performed to determine sperm DNA integrity. N-9 was used as a reference standard and semen added to physiological saline was used as the control. Semen samples were donated by 42 healthy fertile men. The crude extract from the root of PTW could immobilize and kill 100% spermatozoa within 20 s in vitro at the concentrations of 20.0 and 10.0 mg/ml; at the concentration of 5.0 mg/ml, spermatozoa were immobilized in (39.5±3.2) s. In the groups of the crude extract from the root of PTW and N-9 solution, the rate of the normal HOS (tails swollen) and the white head (unstained) was 0%, and the rate of the abnormal HOS (tails unswollen) and red head (stained) was 100%. Sperm DNA fragmentation showed no change in exposure to the crude extract from the root of PTW and N-9 solution. The sperm revival test did not show any spermatozoa that recovered their motilities. The rapid spermicidal activity of the crude extract from the root of PTW in vitro may occur by the disruption of the sperm membrane integrity.  相似文献   

16.
Litsea elliptica Blume leaves have been traditionally used as medicinal herbs because of its antimutagenicity, che-mopreventative and insecticidal properties. In this study, the toxic effects of L. elliptica essential oil against Sprague-Dawley rat's red blood cells (RBCs) were evaluated. L. elliptica essential oil was given by oral gavage 5 times per week for 3 treated groups in the doses of 125, 250, and 500 mg/(kg body weight), respectively, and the control group received distilled water. Full blood count, RBC osmotic fragility, RBC morphological changes, and RBC membrane lipid were analyzed 28 d after the treatment. Although L. elliptica essential oil administration had significantly different effects on hemoglobin (Hb), mean cell hemoglobin concentration (MCHC), mean cell volume (MCV), and mean cell hemoglobin (MCH) in the experimental groups as compared to the control group (P<0.05), the values were still within the normal range. L. elliptica induced morphological changes of RBC into the form of echinoeyte. The percentage of echinocyte increased significantly among the treated groups in a dose-response manner (P<0.001). The concentrations of RBC membrane phospholipids and cholesterol of all treated groups were significantly lower than those of control group (P<0.001). However, the RBC membrane osmotic fragility and total proteins of RBC membrane findings did not differ significantly between control and treated groups (P>0.05). It is concluded that structural changes in the RBC membrane due to L. elliptica essential oil administration did not cause severe membrane damage.  相似文献   

17.
胸腺肽聚乳酸微球的制备和体外释药研究   总被引:4,自引:0,他引:4  
为了寻找适于多肽分子吸收,免疫学上"有效"、"安全",且服用方便的口服制剂,用W/O/W型乳化挥发法制备胸腺肽聚乳酸微球,正交实验方法优化了制备工艺.通过差热分析证明载药微球已较好形成,Lowry法测定药物的含量,计算微球的载药量、包封率及体外释药量.结果表明,所得微球平均粒径为13.8 μm,平均包封率为80.7%,前12 h的体外释药符合Higuchi方程,T1/2=295 min,在25℃和40℃分别放置90d,微球的粒径分布和剩余药量无显著变化.微球的载药量和包封率符合要求,释药半衰期长,具有良好的应用前景.  相似文献   

18.
Tea polyphenols have been shown to have anticancer activity in many studies.In the present study,we investigated effects of theaflavin-3-3'-digallate(TF3),one of the major theaflavin monomers in black tea,in combination with ascorbic acid(AA),a reducing agent,and(-)-epigallocatechin-3-gallate(EGCG),the main polyphenol presented in green tea,in combination with AA on cellular viability and cell cycles of the human lung adenocarcinoma SPC-A-1 cells.The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) assay showed that the 50% inhibition concentrations(IC50) of TF3,EGCG,and AA on SPC-A-1 cells were 4.78,4.90,and 30.62 μmol/L,respectively.The inhibitory rates of TF3 combined with AA(TF3+AA) and EGCG combined with AA(EGCG+AA) at a molar ratio of 1:6 on SPC-A-1 cells were 54.4% and 45.5%,respectively.Flow cytometry analysis showed that TF3+AA and EGCG+AA obviously increased the cell population in the G0/G1 phase of the SPC-A-1 cell cycle from 53.9% to 62.8% and 60.0%,respectively.TF3-treated cells exhibited 65.3% of the G0/G1 phase at the concentration of its IC50.Therefore,TF3+AA and EGCG+AA had synergistic inhibition effects on the proliferation of SPC-A-1 cells,and significantly held SPC-A-1 cells in G0/G1 phase.The results suggest that the combination of TF3 with AA or EGCG with AA enhances their anticancer activity.  相似文献   

19.
稳恒磁场对人白血病细胞K562生长抑制作用研究初报   总被引:5,自引:0,他引:5  
人白血病细胞K5 6 2经3,6 ,9,12 ,2 4 ,36 ,4 8,6 0 ,72h不同时间磁场处理后,利用MTT法检测其生长活性,台盼蓝拒染法进行活细胞计数.结果表明,K5 6 2细胞经9mT稳恒磁场处理0~72h后,从12h起磁场对细胞生长有显著的抑制效应(p <0 .0 5 ) .K5 6 2细胞生长曲线结果与MTT实验具有良好的一致性.  相似文献   

20.
Salvianolic acid B(Sal B) is an active component of traditional Chinese medicine Salvia miltiorrhiza and is used to treat vascular diseases. To better understand its mechanism, the antioxidant capacities of Sal B was evaluated with human endothelial cells under oxidative stress. Human endothelial cells were pretreated with Sal B for 12 h followed by hydrogen peroxide for another 12 h. Production of reactive oxygen species (ROS), activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and concentration of glu-tathione were measured: Protective effect of Sal B on the endothelial cells from hydrogen peroxide-induced damage ' was observed, and ROS production in the cells was found significantly inhibited. Sal B remarkably enhanced the activities of antioxidant enzymes SOD, CAT and GPX. Furthermore, Sal B up-regulated the intracellular glutathione concentration. The results indicate that Sal B protected endothelial cells from oxidative stress by improving the redox status of the cells through enhancing the antioxidant enzyme activities and increasing the reductive glutathione concentration after the oxidative challenge.  相似文献   

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