青蛤凝集素抑菌机制的研究

目的研究青蛤凝集素(CSL)的抑菌机制。方法利用滤纸片法获得青蛤凝集素抑菌结果。针对有抑菌活性的细菌,通过呼吸代谢抑制实验研究凝集素对细菌的糖代谢过程的影响。利用DNA、RNA和蛋白质试剂盒研究凝集素对细菌DNA、RNA和蛋白质合成的影响。利用Griess试剂对细菌NOS活性进行测定。利用ATP检测试剂盒对细菌内的ATP含量进行检测。同时,利用扫描电镜观察细菌形态变化。结果与结论CSL对大肠杆菌、产气荚膜梭菌和枯草芽孢杆菌具有抑菌活性。CSL通过抑制大肠杆菌和产气荚膜梭菌的EMP途径、枯草芽孢杆菌的HMP途径来起抑菌作用。CSL与大肠杆菌、产气荚膜梭菌、枯草芽孢杆菌共培养时,随着CSL浓度的增...     

核桃青皮体外抑菌活性的研究

目的 研究核桃青皮的体外抑菌活性.方法 选取金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌和深红酵母等重要指示菌为标靶,以最低抑菌浓度为指标,采用杯碟法对核桃青皮乙醇提取物的不同极性萃取部位进行抑菌活性的筛选.结果 核桃青皮提取物对金黄色葡萄球菌和深红酵母不敏感,对大肠杆菌和枯草芽孢杆菌有显著的抑制作用;氯仿萃取部位对大肠杆菌...     

伊枯草菌素类抗菌肽抑菌活性及机理研究进展

伊枯草菌素(iturin)家族是一类由革兰阳性芽孢杆菌通过非核糖体途径合成的抗菌肽，为脂肪酸与肽链组成的环肽，具有广谱抗菌活性、低过敏性及低毒性等特点。自发现以来，人们在此抗菌肽抑菌活性研究中收获颇丰，但对其抑菌机理知之甚少。本文从结构特点、体内外合成及抗菌活性等方面，总结了伊枯草菌素类抗菌肽表现的抑菌特征，为今后抑菌机理的揭示提供借鉴。     

新型喹诺酮类化合物的合成及抗菌活性研究

目的 设计、合成一系列新型喹诺酮类化合物,测试其体外抗菌活性.方法 以诺氟沙星为起始原料,经过N-烃化、酰化和缩合共3步反应得到目标化合物,采用微量二倍浓度稀释法,以诺氟沙星、环丙沙星、左氧氟沙星为阳性对照测定目标化合物对金黄色葡萄球菌、枯草芽孢杆菌、铜绿假单胞菌、大肠杆菌、肺炎克雷伯菌的体外抑菌活性.结果 与结论合成...     

2-乙酰吡啶缩肼基二硫代甲酸甲酯及其钴离子配合物的合成和抗菌活性

本文合成了2-乙酰吡啶缩肼基二硫代甲酸甲酯配体(1)及其钴离子(Ⅲ)配合物(2)。采用元素分析、单晶X射线衍射技术对2进行了结构表征。生物活性研究表明,两种化合物对铜绿假单孢杆菌、枯草芽孢杆菌及葡萄牙假丝酵母等均有抗菌活性,初步研究了抗菌机制。     

螠蛏共附枯草芽孢杆菌110次级代谢产物的抑菌抗肿瘤活性研究Δ

摘要：目的 检测螠蛏共附枯草芽孢杆菌110次级代谢产物的抑菌活性组分,并探讨抑菌活性组分的抗肿瘤作用。方法 用0.22 μm滤膜过滤将螠蛏共附枯草芽孢杆菌110的菌体和发酵液分开,用硫酸铵沉淀发酵液的蛋白组分并用SDS-PAGE检测,用滤纸片法分别检测菌株发酵液、菌体及胞外蛋白的抑菌活性,琼脂块法检测抑菌活性组分的抑真菌活性,用海虾毒性法和MTT法检测抑菌活性组分的抗肿瘤活性。结果 螠蛏共附枯草芽孢杆菌110的发酵液抑菌活性远远高于菌体的抑菌活性,发酵液的硫酸铵沉淀物具有很强的抑菌活性,硫酸铵沉淀的110活性粗蛋白主要由分子量约为60、45和25 kDa的3条带组成。110活性粗蛋白对8种真菌指示菌具有抑制作用,其中对辣椒青枯、番茄灰霉和瓜类枯萎的抑菌圈直径超过20 mm。该活性粗蛋白还对白血病细胞K562、肝癌细胞HepG-2和人乳腺癌细胞MDA-MB-231具有抑制作用,其中200 μg/mL的蛋白对人肝癌细胞HepG-2抑制率达74.01%。结论 螠蛏共附枯草芽孢杆菌110胞外蛋白有抗肿瘤活性和广谱抑菌活性,具有潜在的开发价值。     

2-呋喃硫羰基腙衍生物及其过渡金属配位化合物的合成和抑菌活性

本文设计合成了九个2-呋喃硫羰基腙衍生物及其十三个不同的过渡金属配位化合物,并进行了抑菌实验,表明化合物对受试各种细菌均具有不同程度的抑菌作用。与2-呋喃硫羰基踪衍生物相比,配位化合物的抑菌活性发生显著的改变。其中,铜(Ⅱ)、镍(Ⅱ)、锌(Ⅱ)和银(Ⅰ)等配位化合物的活性较强,其它过渡金属配位化合物的活性较低。多数化合物对革兰氏阳性细菌的敏感性大于对革兰氏阴性细菌。     

杆菌霉素D (Bacillomycin D) 的分离纯化及结构鉴定

利用大孔吸附树脂和反相色谱从枯草芽孢杆菌SIPI-2014406的发酵液中纯化得到化合物009和018,纯度均为99.6%。抗菌试验结果显示,化合物009抑菌活性微弱,018对革兰阴性菌具有抑制作用。氨基酸组成、质谱、二级质谱和核磁共振谱分析结果表明,化合物009是normal-C14杆菌霉素D(bacillomycin D),化合物018是其同系物。     

硝基糠醛缩氨基硫脲衍生物的合成与抑菌活性

本文设计合成了１６种糠醛缩氨基硫脲衍生物，并对所合成的化合物进行了抑菌活性实验．结果表明：多种化合物对受试细菌有不同程度的抑制作用，有些化合物抑菌活性很高，很有发展前景。     

昆明山海棠内生真菌ThF-11化学成分抗菌杀线虫作用的研究

目的研究昆明山海棠[Tripterygium hypoglaucum(Levl.)Hutch]内生真菌化学成分及其抗菌杀线虫活性。方法分离、纯化内生真菌Th F-11,利用基因测序对分离的昆明山海棠内生真菌进行鉴定。应用层析法和波谱法对其代谢产物进行分离纯化、结构鉴定。分别采用生物活性测定法、抑菌圈法和试管法测定杀线虫和抑菌活性。结果经ITS鉴定昆明山海棠内生真菌Th F-11为简青霉(Penicillium simplicissimum),波谱法鉴定化合物结构为Penicillic acid[1]、2,4-dimethoxy-6-methylphenol[2]和5(6)-dihydropenicillic acid[3]。杀线虫活性显示化合物[1]随着时间、浓度增加活性逐渐增强,且对大肠杆菌、蜡样芽孢杆菌、枯草芽孢杆菌、金黄色葡萄球菌和绿脓杆菌均具有较强的抑菌活性。结论首次从内生真菌Th F-11获得3个化合物,且化合物[1]具有较强的抑菌、杀线虫的生物活性,值得进一步开发应用。     

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.     

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.     

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.     

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.