促性腺激素释放激素及其受体在肿瘤治疗中的应用

促性腺激素释放激素（GnRH）是由下丘脑神经元分泌的一种十肽类激素,其生理功能是调节垂体前叶促性腺激素的分泌,进而刺激黄体生成素及卵泡刺激素的分泌以调节性激素的水平。GnRH对垂体外的多种外周组织的生理功能也有调节作用。近年研究发现,乳腺、卵巢、子宫内膜、前列腺、胰腺、肺、肝脏发生的肿瘤细胞上均有GnRH受体分布,GnRH类似物可抑制这些肿瘤细胞生长。GnRH及其类似物的抗肿瘤效应是通过调节垂体促性腺激素水平来实现的。本文对GnRH及其受体在肿瘤治疗中的应用进展进行综述。     

青蒿素及其衍生物抗肿瘤作用研究进展

青蒿素及其衍生物是一类高效、速效、低毒的抗疟药物,近年来的研究发现,青蒿素及其衍生物除了具有抗疟作用外,其在体内外亦对多种肿瘤细胞具有选择性抑制和/或杀伤作用。本文对近几年来国内外对其抗肿瘤活性及抗肿瘤作用机制的实验研究进行综述。     

表皮生长因子受体及其抑制剂的研究

表皮生长受体因子属于受体酪氨酸激酶家族成员,其过度表达和/或基因突变与多种肿瘤的形成具有密切的联系。近年来,小分子表皮生长因子受体酪氨酸激酶抑制剂的开发已成为肿瘤治疗领域中的研究热点。这里就表皮生长因子受体及其小分子抑制剂进行简要综述。     

大麻素受体及其Ⅰ型抑制剂的研究进展

目前已经确认的大麻素(cannabinoid,CB)受体有两种亚型:CB1和CB2,它们的分布与生理功能各不相同,其选择性抑制剂的研究也是近年来的一个热点。研究表明,CB1受体抑制剂具有良好的抗肥胖活性。本文综述了CB受体及其Ⅰ型抑制剂的研究进展。     

烟酸受体GPR109a及相关激动剂的研究进展

烟酸是临床应用几十年的降血脂药物,近年来研究发现,烟酸作用于G蛋白偶联受体109a（GPR109a）和GPR109b,该受体主要在脂肪细胞和多种免疫细胞中表达。烟酸受体的发现以及对相关不良反应作用机制的研究为寻找活性更强、不良反应较小的降脂药物开启了一条新的途径,为相关心血管疾病及糖尿病并发症的治疗提供了新的思路。本文对以GPR109a为靶标的药物研究成果进行综述。     

食欲素受体拮抗剂的研究进展

食欲素(orexin)是下丘脑外侧orexin神经元合成和分泌的神经肽,包括orexin-A和orexin-B.Orexin受体是G蛋白耦联受体,有两种亚型:OX1R和OX2R.近年来,食欲素受体及其拮抗剂的研究越来越受到重视,已发现食欲素受体拮抗剂对失眠、肥胖、抑郁症、药物成瘾等疾病具有治疗作用,为人类寻找上述疾病的治疗提供了新的思路.目前,食欲素受体拮抗剂,尤其是双重食欲素受体拮抗剂(DORAs)用来治疗失眠成为研究的热点,已有1个上市药品Suvorexant及处于临床Ⅲ或Ⅱ期研究的药物,发展前景广阔.本文对食欲素受体拮抗剂的研究进展进行综述,以期对该类药物的研究开发和使用有所帮助.     

黄芩抗病毒作用的研究进展及临床应用

黄芩为中医临床常用药物,具有多种药理作用且疗效确切.黄芩包含丰富的天然产物,其中最主要的活性成分是黄酮类化合物.近年来的研究发现黄芩及其黄酮类成分具有较好的抗病毒活性,能够抑制多种病毒的感染与复制.临床上黄芩也常用于治疗一些病毒感染性疾病.因此,本文对黄芩抗病毒的药理作用及临床应用进行综述,为黄芩在病毒感染性疾病方面的深入研究与应用提供一定的参考.     

黑皮质素受体4激动剂的研究进展

黑皮质素受体4（melanocortin-4 receptor，MC4R）是一种参与中枢调节的G蛋白偶联受体，主要存在于皮质、丘脑、下丘脑、脑干。激活MC4R可产生多种生理功能，因此本文就近年来新发现的外源性MC4R激动剂RM-493、RO27-3225和PT-141的生理功能及其研究进展做一综述，旨在为今后临床用药提供参考。     

人血白蛋白的合理应用概述

人血白蛋白是一种血液制品,其生理功能主要是扩充血容量和维持血浆胶体渗透压,还具有载体及维持毛细血管完整性等功能,临床广泛用于多种疾病的治疗。目前在我国人血白蛋白的使用普遍存在适应证掌握不严格及不合理使用的情况,导致医药资源的浪费。另外,随着研究证据的不断更新,白蛋白的应用指征已经发生了新的变化。本文结合近期指南共识及研究证据,对白蛋白的适应证及临床应用进行综述,梳理其应用要点,旨在为白蛋白的合理应用提供参考,促进临床规范用药。     

脑源性神经营养因子的研究进展

近年来,科学研究发现神经营养因子是参与调控神经系统多种生理功能的一种蛋白质。其中,脑源性神经营养因子是一种在脑内合成的小分子二聚体蛋白质,对中枢系统神经元的生长、发育、分化、再生和修复具有重要作用。本文对脑源性神经营养因子的结构、功能、疾病相关性及临床应用前景进行了综述。     

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.     

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 x kg(-1)) or i.p. (50 mg x kg(-1)) administration of an emulsion formulation. 2. Plasma clearance of artemisinin was 12.0 (95% confidence interval: 10.4, 13.0) 1 x h(-1) x kg(-1) in the male rat and 10.6 (95% CI: 7.5, 15.0) 1 x h(-1) x kg(-1) in the female rat suggesting high hepatic extraction in combination with erythrocyte uptake or clearance. Artemisinin half-life was approximately 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。     

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.     

Changes in angiopoietin expression in glomeruli involved in glomerulosclerosis in rats with daunorubicin-induced nephrosis

AIM: To study the potential pathological role of endogenous angiopoietins in daunorubicin-induced progressive glomerulosclerosis in rats. METHODS: Seventy male Wistar rats were allocated randomly into a daunorubicin group (DRB; n=40) or a control group (n=30). The rats in the DRB group were injected with DRB (15 mg/kg), in their tails. Subsequently, at intervals of 1, 2, 4, 6, 8, and 12 weeks, 5 male Wistar rats in each group were chosen randomly for 24 h urinary protein quantitative measurements (24 h UPQM), and determination of plasma tumor necrosis factor alpha (TNF-alpha), angiopoietin-1 (Ang1), and angiopoietin-2 (Ang2) levels. Kidney sections were examined by electron microscopy, Periodic Acid Schiff (PAS) staining, immunohistochemical staining and in situ hybridization histochemistry. RESULTS: As glomerulosclerosis progressed in the DRB group, expression of Ang1 mRNA and protein in glomeruli decreased and expression of TNF-alpha protein, Ang2 mRNA and protein in glomeruli increased. Expression of Ang1 mRNA and protein in glomeruli were negatively correlated with 24 h UPQM, Fn protein expression, and mean area of extracellular matrix (MAECM). In comparison, expression of Ang2 mRNA and protein in glomeruli were positively correlated with 24 h UPQM, Fn protein expression and MAECM; furthermore, there was a positive correlation between plasma Ang2 and 24 h UPQM. Plasma TNF-alpha and expression of TNF-alpha in glomeruli were positively correlated with expression of Ang2 mRNA and protein in glomeruli. There was a negative correlation between Ang1 protein expression and Ang2 protein expression in glomeruli. CONCLUSION: During DRB-induced glomerulosclerosis, podocyte injury led to a shift in the balance of Ang1 and Ang2 in glomeruli. Increased TNF-alpha in plasma and glomeruli may upregulate Ang2 expression in glomeruli. Elevated Ang2 in both plasma and glomeruli may mediate protein permeability through the glomerular filtration barrier. Moreover, local expression of Ang2 may facilitate the progress of glomerulosclerosis by upregulating a component expression of extracellular matrix.     

Hyperkalaemia in patients in hospital

A survey of all laboratory blood specimens with a plasma potassium concentration greater than or equal to 5.5 mmol/L was conducted over a three month period. Of 331 specimens with hyperkalaemia, 71 were excluded because the specimens was haemolysed, old or contaminated. The laboratory served a population of 348,561 and during this time measured the plasma potassium on 25,016 occasions. Sixty-six outpatients and 20 neonates were not evaluated. The survey was undertaken on 86 of 102 inpatients (46 males), 48 of whom were over 66 years of age. Fifty-seven patients were admitted under a medical service and 29 under a surgical service. Fifty-nine had a single episode of hyperkalaemia. Thirty-two underwent a surgical procedure. The commonest contributing factor was impaired renal function which was present in 71 (83%) patients. Although a definitive causative role for drugs could be identified in only five patients, in 52 (60%) patients drugs were a contributing factor (potassium supplements 24, ACE inhibitors 16, nonsteroidal antiinflammatory drugs 12). Thirty-five of the 86 (41%) patients died during their hospital admission. Nineteen of the 35 deaths occurred within three days of the hyperkalaemia being recorded. A normal plasma potassium was eventually documented in 50 of the 86 patients. Of the remaining 36 patients, 25 (69%) subsequently died. In general the treatment of patients with hyperkalaemia focused on identifying and treating the underlying cause. Hyperkalaemia must always be considered seriously and regard given to the overall clinical status of the patient, with particular attention to drug therapy, renal and cardiac function, acid base status and the possibility of sepsis.