地非三唑抑制血管新生作用的研究

目的从细胞、器官、整体三个水平观察地非三唑抑制血管的新生作用。方法细胞水平用MTT法测定地非三唑对人脐静脉内皮细胞的增殖抑制作用;器官水平上利用鸡胚绒毛尿囊膜(CAM)血管新生模型,观察地非三唑抑制CAM血管新生的情况;并在整体水平上采用家兔角膜血管新生模型,于缝线后第3d用地非三唑于结膜囊注射给药,每天观察角膜血管新生情况。结果地非三唑能有效抑制人脐静脉EVC304细胞的增殖,其IC50根据药物作用时间的不同,维持在9～15μg·mL^-1;并能使CAM新生血管明显减少甚至消失,对家兔角膜新生血管也有同样抑制作用。结论地非三唑能抑制血管新生作用。     

重组人可溶性血管内皮细胞

血管内皮细胞生长抑制因子（Vascular Endothelial GrowthInhibitor,VEGI）是从人脐静脉内皮细胞（HUVEC）cDNA文库筛选到的一个TNF超家族新成员。为研究重组可溶性人VEGI对新生血管形成抑制活性,检测了重组可溶性人VEGI对建株人脐静脉内皮细胞（ECV304）增殖抑制活性以及对兔角膜诱生血管、鸡胚尿囊膜（CAM）血管的抑制活性。表明可溶性人VEGI可以直接抑制ECV304内皮细胞的增殖,抑制兔角膜诱生血管、CAM血管形成。VEGI是一种新的血管内皮细胞生长抑制因子,强烈抑制新生血管形成,有望应用于肿瘤的治疗。     

青蒿琥酯抑制新生血管生成的作用

目的　为研究青蒿琥酯成为抗血管生成药物的可能性 ,观察其对新生血管的影响 ,并初步探讨其机制。方法　采用鸡胚绒毛尿囊膜、大鼠主动脉环无血清培养、人脐静脉内皮细胞损伤迁移等实验 ,检测青蒿琥酯对新生血管增殖与迁移的抑制作用。结果　鸡胚绒毛尿囊膜实验表明 ,青蒿琥酯有较强的血管增殖抑制作用 ,对微血管作用强于大血管 ;大鼠主动脉环无血清培养实验表明 ,青蒿琥酯能明显推迟血管新生 ,减少新生血管数量 ;人脐静脉内皮细胞损伤迁移实验表明青蒿琥酯对内皮细胞具有增殖和迁移抑制作用。在这些体内外实验中 ,青蒿琥酯抑制血管生成作用呈剂量依赖性。结论　青蒿琥酯具有抑制新生血管生成作用 ,此作用可能与抑制血管内皮细胞迁移有关。     

革皮氏海参皂苷抑制血管新生作用

目的以革皮氏海参中分离得到的三萜皂苷ho-lothurin A1(HA)和24-dehydroechinoside A(DA)为研究对象,比较研究其抗血管新生的作用。方法采用MTT法和AO/EB染色法检测不同剂量HA和DA对人脐静脉内皮细胞(HUVEC)增殖和凋亡的影响;采用小管形成实验观察HA和DA对HUVEC分化形成小管能力的影响;细胞黏附实验比较研究HA和DA对HUVEC与肝癌细胞HepG2的黏附能力的影响;鸡胚绒毛尿囊膜(CAM)血管新生模型,观察HA和DA抑制CAM血管新生的情况。结果 HA和DA均具有抑制HUVEC增殖的活性(48 h的IC50值分别为4.80、3.82μmol.L-1),并能促进内皮细胞的凋亡;在体外能抑制内皮细胞小管形成,可抑制HUVEC与HepG2细胞间(P<0.01)的黏附,能使CAM新生血管明显减少,其中DA抑制血管新生活性优于HA。结论海参皂苷HA和DA具有抑制血管新生的作用,其活性与其结构相关。     

λ-卡拉胶禀糖体外对血管生成的抑制作用

为探讨λ-卡拉胶寡糖体外对血管生成的抑制作用，采用鸡胚尿囊膜模型（CAM）观察λ-卡拉胶寡糖对CAM血管发育的抑制，发现该寡糖可明显抑制CAM微血管生成，在200μg·egg^-1时，抑制率达54．90％。随后采用MTT法测定λ-卡拉胶寡糖对人脐静脉内皮细胞（HUVEC）增殖的影响，发现该寡糖的细胞毒作用在不同的细胞间具有选择性．对HUVEC的抑制最强，高浓度时（1mg·mL^-1）能明显抑制其增殖．但低浓度（〈250μg·mL^-1）对细胞几乎无毒。对寡糖的细胞迁移和侵袭抑制作用进行检测，并测定其对HUVEC表达基质金属蛋白酶-2（MMP-2）的影响。结果表明，λ-卡拉胶寡糖能有效减缓HUVEC的迁移、侵袭能力，并具有抑制HUVEC中MMP-2表达的作用。该研究说明λ-卡拉胶寡糖通过抑制内皮细胞的增殖、细胞侵袭和迁移达到血管生成抑制的作用。     

魟鱼软骨多糖抗血管形成的实验研究

目的:探讨魟鱼软骨多糖(RCG)对血管形成的作用。方法:原代培养人脐静脉内皮细胞,采用MTT法检测不同浓度RCG对人脐静脉内皮细胞增殖的影响;缝线诱导大鼠角膜新生血管,通过计算新生血管面积评价不同浓度RCG对大鼠角膜新生血管的作用;建立小鼠Lewis肺癌模型,观察不同浓度RCG作用后肿瘤生长情况,计算原发瘤抑制率,免疫组织化学染色计数肿瘤组织微血管密度(MVD)。结果:RCG可明显抑制人脐静脉内皮细胞的体外增殖,IC50为62.93mg.mL-1;与生理盐水组比较,应用不同浓度RCG后新生血管面积明显减少(P<0.01),原发瘤抑制率呈浓度依赖性,MVD值降低(P<0.01)。结论:RCG对实验动物具有良好的抗血管生成活性。     

蝎毒多肽提取物抗肿瘤血管生成作用的实验研究

目的探讨东亚钳蝎蝎毒的多肽提取物PESV的抗血管生成活性和对肿瘤生长的抑制作用。方法①用不同浓度的PESV(4～20mg·L-1)作用于人脐静脉内皮细胞(HUVEC),采用BrdU参入的ELISA法观察HUVEC增殖活性和凋亡水平变化,流式细胞术检测凋亡细胞比例,免疫组化法检测Bal和Bax表达。②观察PESV对鸡胚尿囊膜(CAM)新生血管生成的影响。③皮下注射PESV(0.3mg·kg-1),观察对S180肉瘤和H22肝癌荷瘤小鼠肿瘤生长、肿瘤血管生成和血管生成因子(VEGF和bFGF)表达的影响。结果①体外实验显示,PESV在8～20mg·L-1范围明显抑制HUVEC的增殖活性(与对照组比较,P<0.01),而对乳腺癌细胞MDAMB231的增殖无影响;PESV作用后HUVEC凋亡细胞比例较对照组增加,P<0.05,Bax表达增加;Bcl2表达降低。②0.5mg/CAM和0.8mg/CAM的PESV能明显抑制CAM新生血管的形成。③体内实验显示PESV能明显抑制小鼠S180肉瘤和H22肝癌的肿瘤生长和血管生成水平,并降低肿瘤组织内血管生成相关因子VEGF和bFGF的表达。结论PESV具有良好的体内和体外抗肿瘤血管生成活性,并籍此抑制肿瘤的生长。     

重组人内抑素的抗肿瘤活性

目的观察重组人内抑素抗肿瘤活性及对血管内皮细胞增殖的抑制作用。方法用人癌裸鼠移植性肿瘤及小鼠移植性肿瘤模型对重组人内抑素进行抗肿瘤药效学观察,用MTT法观察其对血管内皮细胞及肿瘤细胞增殖的抑制作用。结果重组人内抑素,可明显抑制人胃癌BGC803和人乳腺癌B37裸鼠移植性肿瘤的生长,对小鼠肝癌H22实体瘤亦呈一定的抑制作用。MTT试验结果显示重组人内抑素可抑制人胎脐静脉血管内皮细胞ECV304的增殖,对人结肠癌HCT-8等肿瘤细胞的增殖无影响。结论重组人内抑素具有较强的抗肿瘤作用,其作用机理可能与抑制血管内皮细胞增殖、抑制肿瘤新生血管形成有关。     

λ-卡拉胶寡糖体外对血管生成的抑制作用

为探讨λ-卡拉胶寡糖体外对血管生成的抑制作用,采用鸡胚尿囊膜模型(CAM)观察λ-卡拉胶寡糖对CAM血管发育的抑制,发现该寡糖可明显抑制CAM微血管生成,在200 μg·egg-1时,抑制率达54.90%.随后采用MTT法测定λ-卡拉胶寡糖对人脐静脉内皮细胞(HUVEC)增殖的影响,发现该寡糖的细胞毒作用在不同的细胞间具有选择性,对HUVEC的抑制最强,高浓度时(1 mg·mL-1)能明显抑制其增殖,但低浓度(＜250 μg·mL-1)对细胞几乎无毒.对寡糖的细胞迁移和侵袭抑制作用进行检测,并测定其对HUVEC表达基质金属蛋白酶-2(MMP-2)的影响.结果表明,λ-卡拉胶寡糖能有效减缓HUVEC的迁移、侵袭能力,并具有抑制HUVEC中MMP-2表达的作用.该研究说明λ-卡拉胶寡糖通过抑制内皮细胞的增殖、细胞侵袭和迁移达到血管生成抑制的作用.     

芸香宁碱抑制血管生成作用的研究

目的：研究芸香宁碱对血管生成的抑制作用,并研究其初步的作用机制。方法用人脐静脉内皮细胞（HUVEC）的生长、迁移实验及体内动物模型－鸡胚绒毛尿囊膜法（CAM 法）研究化合物的体内外抗血管生成作用;用酶联免疫吸附法检测芸香宁碱在非凋亡剂量时对肿瘤细胞培养上清液中 VEGF 蛋白分泌量的影响。结果芸香宁碱对血管内皮细胞具有优先抑制作用,对 HUVEC 的半数抑制剂量为（33．2±0．4）μmol·L －1,而对其他肿瘤细胞的 IC50值均大于这一数值;芸香宁碱在体外能够明显抑制内皮细胞的迁移和对细胞外基质黏附作用,并呈剂量依赖性,体内实验显示30μmol·L －1剂量浓度时显著抑制 CAM新生血管形成;芸香宁碱在15μmol·L －1和30μmol·L －1的浓度剂量时显著抑制人肝癌 HepG2细胞培养上清液中VEGF 蛋白的分泌,具有显著性差异。结论芸香宁碱在非凋亡浓度剂量具有抑制新生血管形成作用,其机制与抑制血管内皮细胞增殖以及抑制肿瘤细胞表达 VEGF 有关。     

Interindividual variability in metabolic activation in humans in vivo

In assessing interindividual variability in metabolic activation, the toxic metabolite is often too unstable for conventional analysis. Possible alternatives include a stable product of the reactive metabolite e.g. cysteinyl derivatives of N-acetyl-4-benzoquinoneimine, the toxic metabolite of paracetamol, adducts with DNA or protein, and indirect measurement of the activity of the enzyme(s) producing the active metabolite. An example of the last approach is the use of furafylline, a highly specific inhibitor of human CYP1A2, to determine the extent of the metabolic activation of the cooked food mutagens PhIP and MeIQx. The extent of inhibition, determined from levels of unchanged amine in urine, is an indirect measure of the activity of the activation pathway. Further refinement of this approach, allied to improved measures of the biological process of interest should prove of value in evaluating interindividual variability and its role in the risk assessment process.     

Quantitative in vivo and in vitro sex differences in artemisinin metabolism in rat

1. The pharmacokinetics of the antimalarial compound artemisinin were compared in the male and female Sprague-Dawley rat after single dose i.v. (20 mg.kg) or i.p. (50 mg.kg) administration of an emulsion formulation. 2. Plasma clearance of artemisinin was 12.0 (95% confidence interval: 10.4, 13.0) l.h. kg in the male rat and 10.6 (95% CI: 7.5, 15.0) l.h. kg in the female rat suggesting high hepatic extraction in combination with erythrocyte uptake or clearance. Artemisinin half-life was 0.5 h after both routes of administration in both sexes. Values for plasma clearance and half-lives did not statistically differ between the sexes. 3. After i.p. administration artemisinin AUCs were 2-fold higher in the female compared with male rat (p 0.001). Artemisinin disappearance was 3.9-fold greater in microsomes from male compared with female livers and it was inhibited in male microsomes by goat or rabbit serum containing antibodies against CYP2C11 and CYP3A2 but not CYP2B1 or CYP2E1. 4. The unbound fraction of artemisinin in plasma was lower (p 0.001) in plasma obtained from the male (8.8 2.0%) compared with the female rat (11.7 2.2%). 5. The possibility of a marked sex difference, dependent on the route of administration, has to be taken into account in the design and interpretation of toxicological studies of artemisinin in this species.     

Theophylline kinetics in peripheral tissues in vivo in humans

Several biochemical and cellular effects have been described for methylxanthines under in vitro conditions. However, it is unknown, whether threshold concentrations required to exert these effects are attained in target tissues in vivo. We therefore employed the microdialysis technique for measuring theophylline concentrations in peripheral tissues under in vivo conditions.Following in vitro and in vivo calibration, microdialysis probes were inserted into the medial vastus muscle and into the periumbilical subcutaneous adipose layer of healthy volunteers. Following single oral dose administration of 300 mg or i.v. infusion of 240 mg theophylline, in vivo time courses of theophylline concentrations were monitored in tissues and plasma. Major pharmacokinetic parameters (c_max, t_max, AUC) were calculated for plasma and tissue time courses. The mean AUC_tissue /AUC_plasma-ratio was 0.56 (p.o.) and 0.55 (i.v.) for muscle and 0.55 (p.o.) and 0.72 (i.v.) for subcutaneous adipose tissue.We conclude that microdialysis provides important information on the distribution and the tissue pharmacokinetics of theophylline.Abbreviations FPIA Fluorescence polarisation immuno assay - AUC Area under the curve - t_max Time to peak concentration - c_max Peak concentration     

休克时血中氧自由基的变化

本实验测定10名休克患者血浆和红细胞的丙二醛(MDA)、血浆总抗的氧化活性(AOA)的含量。结果表明:休克病人红细胞膜和血浆 MDA 含量(4.298±0.722;5.348±0.834)与对照组(3.235±0.682;4.356±1.081)比较明显增高(P<0.05);血浆 AOA(39.65±7.858)与对照组(48.21±10.81)比较明显降低(P<0.01)。提示:休克时,患者机体内自由基反应增强是引起组织细胞损伤的原因之一。     

Polymorphisms in genes involved in neurotransmission in relation to smoking

Smoking behavior is influenced by both genetic and environmental factors. The genetic contribution to smoking behavior is at least as great as its contribution to alcoholism. Much progress has been achieved in genomic research related to cigarette-smoking within recent years. Linkage studies indicate that there are several loci linked to smoking, and candidate genes that are related to neurotransmission have been examined. Possible associated genes include cytochrome P450 subfamily polypeptide 6 (CYP2A6), dopamine D₁, D₂, and D₄ receptors, dopamine transporter, and serotonin transporter genes. There are other important candidate genes but studies evaluating the link with smoking have not been reported. These include genes encoding the dopamine D₃ and D₅ receptors, serotonin receptors, tyrosine hydroxylase, trytophan 2,3-dioxygenase, opioid receptors, and cannabinoid receptors. Since smoking-related factors are extremely complex, studies of diverse populations and of many aspects of smoking behavior including initiation, maintenance, cessation, relapse, and influence of environmental factors are needed to identify smoking-associated genes. We now review genetic polymorphisms reported to be involved in neurotransmission in relation to smoking.     

Tramadol concentrations in blood and in cerebrospinal fluid in a neonate

Based on blood and cerebrospinal fluid samples collected in a full-term neonate, the penetration of tramadol in the central nervous system is described. Following intravenous administration of tramadol, a lag time of about 4 h was observed until full blood–brain equilibration was achieved. This pharmacokinetic observation is in line with a recent pharmacodynamic evaluation of the central opioid effects of tramadol in adults.     

Pradigastat disposition in humans: in vivo and in vitro investigations

1.?Pradigastat is a potent and specific diacylglycerol acyltransferase-1 (DGAT1) inhibitor effective in lowering postprandial triglycerides (TG) in healthy human subjects and fasting TG in familial chylomicronemia syndrome (FCS) patients.

2.?Here we present the results of human oral absorption, metabolism and excretion (AME), intravenous pharmacokinetic (PK), and in vitro studies which together provide an overall understanding of the disposition of pradigastat in humans.

3.?In human in vitro systems, pradigastat is metabolized slowly to a stable acyl glucuronide (M18.4), catalyzed mainly by UDP-glucuronosyltransferases (UGT) 1A1, UGT1A3 and UGT2B7. M18.4 was observed at very low levels in human plasma.

4.?In the human AME study, pradigastat was recovered in the feces as parent drug, confounding the assessment of pradigastat absorption and the important routes of elimination. However, considering pradigastat exposure after oral and intravenous dosing, this data suggests that pradigastat was completely bioavailable in the radiolabeled AME study and therefore completely absorbed.

5.?Pradigastat is eliminated very slowly into the feces, presumably via the bile. Renal excretion is negligible. Oxidative metabolism is minimal. The extent to which pradigastat is eliminated via metabolism to M18.4 could not be established from these studies due to the inherent instability of glucuronides in the gastrointestinal tract.     

Changes in immunoreactive somatostatin in brain following lidocaine-induced kindling in rat

The kindling phenomenon has become a useful model for studying epileptogenesis. The present authors have previously reported increased levels of immunoreactive somatostatin (IR-SRIF) in various regions of the brain of electrically-amygdaloid kindled (EAK) rats. In this study, an examination was made of immunoreactive somatostatin in pharmacologically-kindled (PK) rats. Sixteen male Sprague-Dawley rats were injected intraperitoneally (i.p.) with a subthreshold dose of lidocaine (60 mg/kg), once daily. Once the kindling phenomenon was established, kindled rats (7), non-kindled rats (9) and controls (6) were sacrificed by microwave irradiation. Another group of 5 rats was injected with a single suprathreshold dose of lidocaine (110 mg/kg) and killed 10 min after the resultant seizure. Various brain areas were removed and assayed for immunoreactive somatostatin in kindled rats. Immunoreactive somatostatin was significantly greater than in controls in the amygdala (56%; P less than 0.02), entorhinal + piriform cortex (50%; P less than 0.05) and hypothalamus (29%; P less than 0.02). In non-kindled rats, immunoreactive somatostatin increased only in the amygdala (58%; P less than 0.02). No difference was found in the immunoreactive somatostatin content of rats injected with an suprathreshold dose of lidocaine compared to controls. The alteration of immunoreactive somatostatin, in both lidocaine-kindled and electrically-amygdaloid kindled rats suggests a possible role of this neuropeptide in kindling.