功能基修饰的脑靶向递药系统的研究概况

目的:研究功能基修饰的脑靶向递药系统,为提高脑靶向递药系统的靶向效率提供参考。方法:以"功能基""修饰""脑靶向""Functional group""Modified""Brain-targeting"等为关键词,组合查询2001年1月-2018年12月在中国知网、万方数据、维普网、PubMed、Elsevier、Springer Link等数据库中的相关文献,对功能基修饰的脑靶向递药系统进行综述。结果与结论:共检索到相关文献394篇,其中有效文献41篇。脑靶向包括受体介导(介导的受体如转铁蛋白受体、低密度脂蛋白受体、N-乙酰胆碱受体等)、转运体介导(介导的转运体如葡萄糖转运体、谷胱甘肽转运体等)、吸附介导。以上述受体、转运体的配体作为功能基,采用共价键结合或非共价键连接方法进行修饰,构建脑靶向递药系统;功能基通过与相应受体或转运体特异性结合,使药物跨越血脑屏障(BBB)并且在脑内病灶部位释药;除此之外,还可通过功能基带有的正电荷与BBB膜上的负电荷发生静电吸附作用产生非特异性的吸附,介导药物进入脑内。基于受体介导、转运体介导、吸附介导的靶向方式,有望提高脑组织中的药物浓度,提高中枢神经系统疾病的治疗效果,降低毒副作用及不良反应。与受体介导、转运体介导、吸附介导相比较,双级靶向可同时修饰两种靶向分子(一种靶向分子靶向于BBB,另一种靶向分子靶向于病灶),有望提高脑部疾病的治疗效果并降低药物在非病灶部位的蓄积,是一种更为理想的手段。在后续相关研究中建议开发新靶点和新型靶向分子,进一步提高脑靶向递药系统的靶向效率,为开发操作简单、成本低廉的脑靶向递药系统提供参考。     

短肽在靶向药物递送系统中的研究进展

近年来研究发现许多肿瘤细胞表面高表达一些肽类受体，这些肽类受体与相应的配体亲和性高，能以配体-受体方式特异性结合。以小片段活性肽作为导向物形成复合物而发展的靶向药物递送系统，能够将药物定向转运到靶细胞内，显示了良好的研究价值和应用前景。如蛙皮素/胃泌素释放肽受体介导的靶向药物递送系统、生长抑素受体介导的靶向药物递送系统、十肽SynB₃受体介导的靶向药物递送系统、黄体酮释放激素受体介导的靶向药物递送系统及其他肽类受体介导的靶向药物递送系统，其中短肽作为靶向基团与阿霉素、吡咯阿霉素、甲氨蝶呤、顺铂和喜树碱等结合形成高效的复合物，用于表达有相应受体的肿瘤，获得靶向治疗的研究非常有意义。     

叶酸受体介导的靶向给药研究进展

目的：介绍叶酸受体介导的靶向给药研究进展。方法：根据近年来的文献资料，对叶酸受体介导的靶向给药研究进行综述。结果：叶酸受体可以与叶酸及其类似物特异性结合，从而提高药物在肿瘤、关节炎的组织分布，达到靶向诊断、治疗的目的。结论：叶酸受体介导的靶向给药是一种很有前景的给药方式。     

乌司他汀对体外循环下冠脉旁路移植术患者围手术期肺脏的保护作用

目的介绍去唾液酸糖蛋白受体（asialoglycoprotein receptor,ASGPR）介导的药物和基因肝靶向作用和机制,及其在治疗肝癌和乙型肝炎实验研究方面的最新进展。方法查阅和选取针对性强、相关度高的文献,总结和归纳ASGPR介导的药物和基因肝靶向用于治疗肝癌和乙型肝炎的最新研究进展。结果ASGPR是肝细胞的一种重要且高效的内吞受体,可用于介导药物和基因的肝靶向递送。结论ASGPR介导的药物和基因肝靶向有望成为肝癌和乙型肝炎治疗的有效手段。     

去唾液酸糖蛋白受体介导的肝靶向研究进展

目的 介绍去唾液酸糖蛋白受体(asialoglycoprotein receptor,ASGPR)介导的药物和基因肝靶向作用和机制,及其在治疗肝癌和乙型肝炎实验研究方面的最新进展。方法 查阅和选取针对性强、相关度高的文献,总结和归纳ASGPR介导的药物和基因肝靶向用于治疗肝癌和乙型肝炎的最新研究进展。结果 ASGPR是肝细胞的一种重要且高效的内吞受体,可用于介导药物和基因的肝靶向递送。结论 ASGPR介导的药物和基因肝靶向有望成为肝癌和乙型肝炎治疗的有效手段。     

VEGFR Ⅱ介导靶向微泡显像剂的制备及体外肿瘤靶向性实验研究

摘 要 目的：制备血管内皮生长因子受体Ⅱ（VEGFRⅡ）介导的靶向六氟化硫微泡显像剂,并评价其对乳腺癌细胞MCF 7的靶向性。 方法: 采用薄膜分散 超声法制备六氟化硫微泡显像剂,以粒径分布为评价指标,通过Box-Behnken效应面法优化六氟化硫微泡显像剂的处方,采用吸附法制备VEGFRⅡ介导靶向微泡显像剂,并对VEGFRⅡ介导靶向微泡显像剂的表观形态、粒径分布、Zeta电位进行表征;用免疫荧光法检测VEGFRⅡ介导靶向微泡显像剂的靶向作用。结果: VEGFRⅡ介导靶向微泡显像剂的平均粒径为（3.81±0.32）μm,多聚分散系数为0.261±0.037,Zeta电位为（-25.7±2.8）mV;透射电镜观察其大小比较均匀,呈规则球形或类球形分布;免疫荧光实验结果显示VEGFRⅡ介导靶向微泡显像剂在体外能与乳腺癌细胞MCF 7特异性结合。结论:通过吸附法可成功制备VEGFRⅡ介导靶向微泡显像剂,在体外具有较强的寻靶能力。     

受体介导的肝靶向载药系统研究进展

介绍近几年已报道的有关受体介导的肝靶向载药系统的研究情况。近年来受体介导的肝靶向载药系统的研究取得了一些可喜进展,相关配体-受体可与药物、脂质体、纳米粒、基因、偶联物等相连,提高药物或载体的肝靶向能力。受体介导机制在肝靶向载药系统的研究领域具有广阔的应用前景,尤其是肝脏特异性受体的不断发掘,丰富了肝主动靶向的理论体系,展示了肝脏疾病治疗的美好未来。     

乳腺癌靶向治疗的新策略

目前,乳腺癌的常规治疗手段如化疗、放疗等存在严重的全身副作用,为此,开展乳腺癌的靶向治疗研究具有重大意义。本文综述了乳腺癌靶向治疗的3个研究领域:抗体介导的靶向、微载体介导的靶向、乳腺癌干细胞靶向,并阐述这些治疗策略的基本研究思路,分析这些新的治疗策略面临的一些问题,从而提出解决这些问题的相关见解。     

受体介导脂质体的研究进展

配体修饰脂质体通过受体介导的内吞作用主动靶向药物至靶位,增加了药物靶向的特异性,减少了对非靶组织器管损伤,提高了疗效,是一种具有广阔发展前景的剂型。本文综述了近年来受体介导脂质体的研究进展。     

叶酸受体介导的靶向给药研究进展

叶酸受体可以与叶酸及其类似物特异性结合,通过介导细胞内化将其摄入细胞胞浆。利用叶酸受体在肿瘤和关节炎细胞的过度表达,使药物与叶酸结合,以叶酸受体为作用靶点,即可将药物主动靶向肿瘤和关节炎细胞,从而提高药物在肿瘤、关节炎的组织分布,达到靶向诊断、治疗的目的。本文就叶酸受体及其组织分布,叶酸受体介导的内吞作用,叶酸受体介导的肿瘤和关节炎的靶向诊断、治疗的研究进展进行了综述。     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Inhibition of synaptosomal uptake of amino acid transmitters by diamines

Reports of the inhibitory effects of diaminocarboxylic acids on the uptake of amino acid transmitters led the present authors to examine the effects of simple aliphatic diamines on the synaptosomal uptake of glutamate, aspartate, GABA and glycine. The diamines studied were the series from ethylenediamine through to 1,7-diaminoheptane; DL-2,4-diaminobutyric acid (DABA) was also tested for comparative purposes. The greatest inhibition seen was on the uptake of glycine and GABA. Weaker effects on uptake were seen with glutamate, while aspartate was unaffected. The patterns of inhibition for glycine and GABA were similar and the effects were dose-dependent. 1,2-Diaminopropane was the most inhibitory, followed by ethylenediamine and 1,7-diaminoheptane. The reported inhibitory effects of DL-2,4-diaminobutyric acid on the uptake of GABA and glutamate were confirmed; comparable inhibition of the uptake of glycine and aspartate was seen but the effects on GABA were most potent. Inhibition of the uptake of GABA by 1,2-diaminopropane was approximately one fifteenth that reported for DL-2,4-diaminobutyric acid. The inhibition by diamine of the uptake of glycine and GABA can provide an explanation of the depressant effects of diamines, seen after ventricular administration; however, the excitotoxic effects of the diamines 1,3-diaminopropane through to 1,7-diaminoheptane could not be explained by the present results.     

Inhaled therapeutics for prevention and treatment of pneumonia

The lungs are the most common site of serious infection owing to their large surface area exposed to the external environment and minimum barrier defense. However, this architecture makes the lungs readily available for topical therapy. Therapeutic aerosols include those directed towards improving mucociliary clearance of pathogens, stimulation of innate resistance to microbial infection, cytokine stimulation of immune function and delivery of antibiotics. In our opinion inhaled antimicrobials are underused, especially in patients with difficult-to-treat lung infections. The use of inhaled antimicrobial therapy has become an important part of the treatment of airway infection with Pseudomonas aeruginosa in cystic fibrosis and the prevention of invasive fungal infection in patients undergoing heart and lung transplantation. Cytokine inhaled therapy has also been explored in the treatment of neoplastic and infectious disease. The choice of pulmonary drug delivery systems remains critical as air-jet and ultrasonic nebulizer may deliver sub-optimum drug concentration if not used properly. In future development of this field, we recommend an emphasis on the study of the use of aerosolized hypertonic saline solution to reduce pathogen burden in the airways of subjects infected with microbes of low virulence, stimulation of innate resistance to prevent pneumonia in immunocompromised subjects using cytokines or synthetic pathogen-associated molecular pattern analogues and more opportunities for the use of inhaled antimicrobials. These therapeutics are still in their infancy but show great promise.     

Recommandations de bon usage des carbapénèmes

Carbapenems are being increasingly used because of the widespread dissemination of antibiotic resistance among Gram-negative bacilli, especially of extended-spectrum beta-lactamases; this increasing use raises the concern of loss of activity for this antimicrobial class following the emergence of carbapenemases. The current guideline from the Anti-infective drugs Committee of the Assistance publique-Hôpitaux de Paris (AP–HP) group emphasizes the careful and limited use of carbapenems, comparing the respective characteristics of the four available molecules, and specifies their indications in clinical hospital practice, with possible alternatives.     

Bioavailabilities of rectal and oral methadone in healthy subjects

AIMS: Rectal administration of methadone may be an alternative to intravenous and oral dosing in cancer pain, but the bioavailability of the rectal route is not known. The aim of this study was to compare the absolute rectal bioavailability of methadone with its oral bioavailability in healthy humans. METHODS: Seven healthy subjects (six males, one female, aged 20-39 years) received 10 mg d(5)-methadone-HCl rectally (5 ml in 20% glycofurol) together with either d(0)-methadone intravenously (5 mg) or orally (10 mg) on two separate occasions. Blood samples for the LC-MS analyses of methadone and it's metabolite EDDP were drawn for up to 96 h. Noninvasive infrared pupillometry was performed at the same time as blood sampling. RESULTS: The mean absolute rectal bioavailability of methadone was 0.76 (0.7, 0.81), compared to 0.86 (0.75, 0.97) for oral administration (mean (95% CI)). Rectal absorption of methadone was more rapid than after oral dosing with Tmax values of 1.4 (0.9, 1.8) vs. 2.8 (1.6, 4.0) h. The extent of formation of the metabolite EDDP did not differ between routes of administration. Single doses of methadone had a duration of action of at least 10 h and were well tolerated. CONCLUSIONS: Rectal administration of methadone results in rapid absorption, a high bioavailability and long duration of action. No evidence of presystemic elimination was seen. Rectal methadone has characteristics that make it a potential alternative to intravenous and oral administration, particularly in cancer pain and palliative care.     

Current concepts of the actions of paracetamol (acetaminophen) and NSAIDs

There is much uncertainty about the mechanism of action of paracetamol (acetaminophen). It is commonly stated that, unlike the non-steroidal anti-inflammatory drugs (NSAIDs), it is a weak inhibitor of the synthesis of prostaglandins. This conclusion is made largely from studies in which the synthesis of prostaglandins was measured in homogenized tissues. However, in several cellular systems, paracetamol is an inhibitor of the synthesis of prostaglandins with IC₅₀ values ranging from approximately 4 μM to 200 μM. Paracetamol is not bound significantly to plasma proteins and therefore the concentrations in plasma can be equated directly with those used in in vitro experiments. After oral doses of 1 g, the peak plasma concentrations of paracetamol are approximately 100 μM and the plasma concentrations are therefore in the range where marked inhibition of the synthesis of prostaglandins should occur in some cells. Paracetamol is metabolized by the peroxidase component of prostaglandin H synthase but the relationship of this to inhibition of the cyclooxygenase or peroxidase activities of the enzyme is unclear. Paracetamol is also metabolized by several other peroxidases, including myeloperoxidase, the enzyme in neutrophils which is responsible for the production of hypochlorous acid (HOCl). The metabolism of paracetamol by myeloperoxidase leads to the decreased total production of HOC1 by both intact neutrophils and isolated myeloperoxidase, even though the initial rate of production of HOC1 is increased. The IC₅₀ value, derived from inhibition of the total production of HOC1 by isolated myeloperoxidase, is 81 μM. Several NSAIDs inhibit functions of neutrophils in media containing low concentrations of protein but their effects, in contrast to that of paracetamol, are generally produced only at concentrations greater than those of the unbound drug in plasma during treatment with the NSAIDs. However, neutrophils isolated during treatment with NSAIDs, such as piroxicam, ibuprofen and indomethacin show decreased function. Paracetamol has little or no anti-inflammatory activity by itself but may potentiate the clinical activity of NSAIDs in the treatment of rheumatoid arthritis.     

Attenuation of morphine tolerance and withdrawal syndrome by coadministration of nalbuphine

Morphine has been used widely on the treatment of many types of chronic pain. However the development of tolerance to and dependence on morphine by repeat application is a major problem in pain therapy. The purpose of the present study was to investigate whether combined administration of nalbuphine with morphine affects the development of tolerance to and dependence on morphine. We hypothesize that the use of nalbuphine, κ-agonist may prove to be useful adjunct therapy to prevent morphine-induced undesirable effects in the management of some forms of chronic pain. Morphine (10 mg/kg) was injected to rats intraperitoneally for 5 day. The variable dose of nalbuphine (0.1, 1.0 and 5.0 mg/kg) was administered (i.p.) in combination with morphine injection. The development of morphine tolerance was assessed by measuring the antinociceptive effect with the Randall-Selitto apparatus. The development of dependence on morphine was determined by the scoring the precipitated withdrawal signs for 30 min after injection of naloxone (10 mg/kg, i.p.). Nalbuphine did not attenuate antinociceptive effect of morphine in rats. Interestingly, combined administration of morphine with nalbuphine (10∶1) significantly attenuated the development of dependence on morphine. The elevation of [³H]MK-801 binding in frontal cortex, dentate gyrus, and cerebellum after chronic morphine infusion was suppressed by the coadministration of nalbuphine. In addition, the elevation of NR1 expression by morphine was decreased by the coadministration of nalbuphine in rat cortex. These results suggest that the coadministration of nalbuphine with morphine in chronic pain treatment can be one of therapies to reduce the development of tolerance to and dependence on morphine.     

人口腔扁平苔藓及口腔鳞状细胞癌survivin表达的研究

目的探讨凋亡抑制因子survivin、在口腔扁平苔藓(OLP)、口腔鳞状细胞癌(OSCC)中的表达及意义。方法采用免疫组化链酶素抗生物素蛋白过氧化物酶(S-P)法检测40例糜烂型OLP组织及40例OSCC组织、26例正常口腔黏膜组织survivin基因的表达,并分析其意义。结果 survivin蛋白在正常口腔黏膜中1例表达,占4%,40例糜烂型OLP组织中12例survivin蛋白阳性表达,占30%,40例OSCC组织中22例survivin蛋白阳性表达,占55%。survivin蛋白在正常口腔黏膜组织与OSCC组织中的表达和糜烂型OLP组织中的表达差异均有显著性(P<0.05),survivin表达与OSCC组织分化程度无明显相关关系。结论 survivin基因在OSCC的发生发展中起重要作用。与OLP向OSCC转变有关。