经鼻脑靶向递药系统的研究进展

鼻腔与脑在解剖生理上的独特联系使得鼻腔给药作为脑内递药途径成为可能.鼻腔给药作为脑靶向的途径之一,可有效地使通过其他给药途径不易透过血脑屏障的药物绕过血脑屏障到达脑部,为中枢神经系统疾病的治疗提供了一种极有发展前景的脑内递药途径.就鼻腔给药脑靶向的依据、影响因素、评价方法、剂型等方面对经鼻脑靶向递药系统的研究现状进行总结.     

经鼻纳米递药系统在中枢神经系统疾病治疗中的研究进展

中枢神经系统疾病治疗药物的脑内递送通常受限于血脑屏障。经鼻给药作为脑靶向递药的一种无创给药方式，可绕开血脑屏障，实现药物至脑部的直接、高效靶向输送，在中枢神经系统疾病治疗中具有极大应用潜力。然而，鼻腔黏液纤毛清除力等屏障限制了经鼻给药递送效果。依托纳米递药技术的发展，经鼻纳米递药系统为中枢神经系统疾病的治疗带来了新的希望。本文综述了经鼻入脑递药通路、常见经鼻纳米递药系统及其特性和治疗应用进展，为基于中枢神经系统疾病治疗的经鼻纳米递药系统设计提供思路和方法。     

脑靶向性鼻腔给药的研究进展

鼻腔给药作为脑靶向给药的途径之一,可有效地使通过其他给药途径不易透过血脑屏障的药物绕过血脑屏障,靶向递送到脑部,为中枢神经系统疾病的治疗提供一种极有发展前景的给药途径.现从药物由鼻腔到脑的转运方式、影响因素、剂型、评价方法以及增强脑靶向性的方法等方面,对近年来鼻腔给药脑靶向性的研究进展进行综述.     

经鼻递脑机制及基于EPR效应的脑靶向脂质体的研究进展

鼻腔与脑在解剖生理结构上的独特联系使得鼻腔给药作为脑内递药途径成为可能,而作为特殊给药系统的脂质体具有鼻腔给药的诸多特点,经鼻腔给药并且利用肿瘤的长滞留效应（EPR效应）或"炎症靶向"达到脑靶向作用,可增加药物的脑内递送。近年来经鼻递药结合EPR效应的策略越来越受到关注,本文归纳总结了近些年国内外有关经鼻递脑途径的机制、影响因素,探讨了经鼻给药结合EPR效应的脑靶向脂质体在中枢神经系统疾病方面的相关研究。     

经鼻腔给药靶向中枢神经系统的研究进展

目的脑靶向给药系统是药学及神经病、肿瘤等相关医学研究中的一个非常活跃的研究领域。方法而经鼻腔给药靶向中枢神经系统,是其中研究的一个重要给药途径。结果本文综述了药物经鼻腔进入中枢神经系统的生理机制、药物在鼻腔的吸收及药物靶向中枢神经系统影响因素。结论虽然绝大多数研究还处于实验阶段,但现阶段的研究成果表明,其临床应用具有广阔的前景。     

透血脑屏障制剂的研究进展

透血脑屏障的研究是药剂学研究中的一个热点和难点，目前研究较多的途径是静脉注射纳米粒和鼻腔给药。综述了纳米粒的载药方法和透血脑 屏障的机制，通过鼻腔给药实现透血脑屏障的途径，影响药物从嗅觉区进入中枢神经系统的因素以及大分子药物利用该途径的可能性。     

载药纳米粒透过血脑屏障机制的研究进展

血脑屏障是维持中枢神经系统内环境稳定的结构基础,有效保护脑组织避免外源性有害物质侵害,但也阻碍许多治疗药物进入脑内,限制了中枢神经系统药物的临床应用。如何有效透过血脑屏障成为此类药物发挥治疗作用的关键环节。纳米粒作为一种新型药物载体,能携载药物透过血脑屏障进入脑组织,提高脑内药物浓度,实现脑内靶向给药。本文对载药纳米粒及其透过血脑屏障机制的研究进展作一综述。     

抗癫痫药物鼻腔给药治疗癫痫发作研究进展

以全身疾病为治疗目的的鼻腔给药具有相对生物利用度高、吸收迅速、起效快、使用方便等特点,而且药物可以绕过血脑屏障、具有一定的脑靶向性,非常适合于癫痫发作的急救、自救治疗。笔者就抗癫痫药物鼻腔给药治疗癫痫发作的研究进展,从药物动力学、药效学、临床应用等方面进行综述。     

多肽类药物鼻腔给药研究进展

随着生物制药技术的发展,越来越多的多肽类药物在医药领域得到应用。但由于这类药物稳定性不佳、口服易被酶解等问题,临床多采用注射途径给药。鼻腔给药不仅能够克服口服给药的首过效应、注射给药的顺应性差等问题,而且具有脑靶向、低剂量高活性的优点。本文主要就多肽类药物的鼻腔给药进行综述,系统地介绍了鼻腔的组织构造,药物本身性质、制剂的特性和鼻腔内环境对药物鼻腔吸收的影响,以及通过添加吸收促进剂、酶抑制剂和设计成不同药物载体等方法改善药物鼻腔吸收,并叙述了鼻腔给药的研究热点-鼻脑传递,为后续相关制剂研发提供参考。     

鼻粘膜作为脑内递药途径的研究进展

20世纪 90年代以来 ,药物传输系统尤其是靶向给药体系成为药学研究的热点 ,但目前的研究主要集中在肝、脾和肺等靶向方面 ,对于脑内靶向却较少涉及。脑部是靶向给药的一个重要部位 ,很多药物必须进入脑内才能发挥疗效 ,然而由于血脑屏障(ｂｌｏｏｄ ｂｒａｉｎｂａｒｒｉｅｒ ,ＢＢＢ)的存在 ,常规途径给药后在脑内的药物浓度都比较低 ,限制了对脑部疾病的治疗。由于鼻粘膜在解剖生理上与脑部存在着独特的联系 ,因此有望在脑内递药领域有所突破。本文就鼻粘膜作为脑内递药途径的研究作一综述。1　鼻粘膜作为脑内递药途径的研究进展我国古代…     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

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.     

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.