维生素D受体对内毒素感染小鼠肺组织肾素-血管紧张素系统的影响

目的研究维生素D受体(Vitamin D receptor,VDR)对内毒素感染小鼠肺组织肾素-血管紧张素系统的影响。方法随机选取15只C57BL/6源性的野生小鼠(WT组)和15只VDR敲除小鼠(KO组),予LPS腹腔注射并分别于注射前及注射后8、16 h各组随机选取5只小鼠,比较两组小鼠一般状态的变化;实时定量PCR测定两组小鼠肺组织中血管紧张素原(AGT)、肾素(Renin)、肾素受体(ReninR)、血管紧张素转化酶(ACE)、血管紧张素Ⅱ(AngⅡ)、血管紧张素Ⅱ-1型受体(AT1R)mRNA的表达水平及支气管肺泡灌洗液中AngⅡ水平及Renin活性变化情况。结果一般状态比较,注射LPS后,两组小鼠均出现不良反应,KO组较WT组不良反应症状明显。LPS注射前,KO组肺组织中ACE、AngⅡ的mRNA表达水平较WT组升高(P<0.05),LPS注射后8、16 h时,KO组肺组织中Renin、ACE、AngⅡ、AT1R水平及肺泡灌洗液中AngⅡ水平、Renin活性均明显高于WT组(P<0.01),LPS注射16 h时,KO组AGT水平明显高于WT组(P<0.01)。结论维生素D受体在内毒素感染时抑制肺组织中肾素-血管紧张素系统的激活,进而对肺组织起到保护作用。     

活性维生素D类似物对内毒素感染小鼠肾脏细胞因子的影响

目的研究活性维生素D类似物对内毒素感染小鼠肾脏细胞因子的影响。方法将C57 BL/6源性野生小鼠(20只)随机分为正常对照组(CON组)、帕立骨化醇组(P组)、脂多糖组(LPS组)、帕立骨化醇+脂多糖组(P+LPS组)。比较各组小鼠一般状态,应用ELISA试剂盒检测小鼠血清肌酐含量,实时定量PCR法测定小鼠肾脏中细胞因子水平。结果一般状态比较,P+LPS组小鼠较LPS组小鼠不良反应减轻。各组小鼠肾脏形态学及血清肌酐水平未见明显差异。P+LPS组肾脏组织细胞因子IL-1β、ICAM、TNF-α、INF-γ表达比LPS组明显下降(P<0.05)。结论活性维生素D类似物能显著减少内毒素感染小鼠肾脏组织中IL-1β、ICAM、TNF-α、INF-γ的含量,减轻炎性细胞因子介导的肾脏损伤,从而起到对肾脏的保护作用。     

维生素D在DSS诱导的实验性肠炎中的作用研究

目的探讨维生素D在2.5%硫酸葡聚糖钠(DSS)诱导的实验性肠炎中的作用。方法随机抽取C57BL/6源性的野生小鼠10只和VDR敲除小鼠10只分别为对照组和实验组,将DSS加入饮用水中配成2.5%DSS溶液分别喂食,评估两组症状评分及生存时间。另行体外实验,应用5%的DSS溶液刺激Caco-2细胞单层,实验组加入1,25(OH)2D3,对照组不予额外处理,测量两组细胞跨膜电阻。结果正常野生鼠对2.5%DSS诱导的实验性肠炎可耐受,VDR敲除鼠出现严重腹泻,直肠出血,体重显著降低等,相对于对照组症状评分增高,生存时间缩短。对照组的细胞跨膜电阻在4 h内逐渐下降,而实验组细胞的跨膜电位在初始阶段有所下降,4 h后恢复正常。结论维生素D在2.5%DSS诱导的实验性肠炎中能够起到保护作用。在体外试验中,1,25(OH)2D3能够抵御DSS诱导的实验性肠炎,为进一步研究维生素D及其信号系统的功能提供了理论依据。     

血管紧张素Ⅱ1型受体拮抗剂用于脓毒症大鼠的实验研究

目的观察血管紧张素Ⅱ1型受体拮抗剂氯沙坦对内毒素诱导的脓毒症大鼠的干预效果。方法 SD大鼠30只随机分成生理盐水对照组(Control组,n=10)、脓毒症组(LPS组,LPS 12 mg·kg-1,iv,n=10)和氯沙坦组(LOS组,氯沙坦50 mg·kg-1 ip,30 min后LPS 12 mg·kg-1 iv,n=10)。LPS注射6 h后抽血检测一氧化氮(NO)、丙二醛(MDA)及IL-1β、TNF-α血浆浓度,随即处死大鼠,分离胸主动脉,测定各组胸主动脉核因子κB抑制蛋白(inhibitor ofNF-κB,IκB)mRNA和蛋白的表达。结果 LPS组NO、MDA、IL-1β及TNF-α血浆浓度较对照组明显升高(P<0.01),经LOS干预后上述指标明显降低(P<0.01);大鼠胸主动脉IκB mRNA和蛋白在LPS组中的表达较对照组均明显降低(P<0.01),而LOS组中IκB的mRNA和蛋白表达较LPS组明显回升(P<0.01)。结论血管紧张素Ⅱ1型受体拮抗剂氯沙坦对内毒素诱导的脓毒症大鼠有抗炎作用。     

内毒素诱导生长激素不敏感的机制

目的:从受体和受体后水平探讨内毒素诱导的生长 激素(GH)不敏感的发生机制.方法:采用SD大鼠,静脉和皮下分别或同时注射LPS和GH.用逆转录聚合酶链反应测定肝组织胰岛素样生长因子-Ⅰ(IGF-Ⅰ),生长激素受体(GHR)和细胞因子信号传导抑制子-3(SOCS-3)mRNA的表达;用放免法测定血清GH水平;用酶联免疫吸附测定法测定血清肿瘤坏死因子α(TNF-α)和白介素-6(IL-6)水平.结果:注射LPS后血清GH水平5对照组均无明显差异,但肝组织IGF-Ⅰ和GHR mRNA的表达明显下调;正常鼠肝组织SOCS-3 mRNA微弱表达,注射LPS后显著上调.LPS刺激TNF-α和IL-6的释放,IL-6升高的水平与SOCS-3 mRNA表达的上调成高度正相关.对照组大鼠注射外源性GH后肝组织IGF-ⅠmRNA的表达明显上调,但它不能阻止内毒素血症鼠IGF-Ⅰ mRNA表达的下降.两种剂量的LPS(7.5mg/kg和5.0mg/kg)注射产生同样的IGF-Ⅰ mRNA下调水平,但大剂量LPS注射诱导更多的GHR mRNA的表达下调和SOCS-3 mRNA的表达上调.结论:内毒素诱导的生长激素不敏感的机制在受体水平与GHR mRNA的表达下调有关,在受体后水平与SOCS-3 mRNA的表达上调有关.受体后水平的抑制与IL-6分泌的增加密切相关.     

血栓调节蛋白和纤溶酶原激活物抑制剂与糖尿病心肌病变的相关关系

目的探讨血浆血栓调节蛋白(TM)和纤溶酶原激活物抑制剂(PAI)-1在糖尿病心肌病变中的作用及相互关系。方法Wistar大鼠60只随机分为实验组(36只)和对照组(24只),实验组一次性腹腔注射链脲佐菌素(STZ),对照组腹腔注射枸椽酸缓冲液。分别于注射后4、8、12周时每组各处死8只取血测TM和PAI-1,并同时取心脏组织制片,在光镜和透射电镜下观察心肌的病理改变。结果实验组血浆TM和PAI-1均在第4周时较正常对照组上升(P<0.05),在8、10周时呈持续上升趋势(P<0.01),实验组血浆TM和PAI-1,呈正相关(r=0.786,P<0.01),对照组的血浆TM和PAI-1无相关。心肌超微结构在第4周出现病理改变,并随着时间延长,8、12周更加明显。结论血浆TM和PAI-1升高在糖尿病心肌病中起着重要作用。     

白藜芦醇对慢性肝损伤模型小鼠的肝保护作用研究

目的:研究白藜芦醇对慢性肝损伤模型小鼠的肝保护作用及内毒素(Lps)刺激引起肝脏枯否细胞(KCs)分泌细胞因子的变化。方法:取小鼠36只随机均分为正常对照组(正常饮食)、模型组(高脂饮食)、药物组(高脂饮食,0.5%白藜芦醇10mL·kg-1)、阳性对照组(高脂饮食,联苯双酯150mg·kg-1),每隔1日灌胃给药1次,10周后每组抽取7只小鼠,腹主动脉采血测定血浆中丙氨酸氨基转移酶(ALT)、白细胞介素-6(IL-6)、IL-10、肿瘤坏死因子-α(TNF-α)水平;分离培养肝脏KCs,检测在Lps刺激下KCs上清液中IL-6、IL-10、TNF-α的水平。结果:与模型组比较,药物组和阳性对照组小鼠血浆中ALT、IL-6水平明显降低(P<0.05),IL-10、TNF-α无明显变化;小鼠肝脏KCs上清液中IL-6、TNF-α水平明显降低,IL-10水平明显升高(P<0.05或P<0.01)。结论:白藜芦醇可能通过降低KCs对促炎因子(IL-6、TNF-α)的表达,提高KCs对抑炎因子(IL-10)的表达,来实现其肝脏保护作用。     

板蓝根对脂多糖刺激鼠释放炎性细胞因子的影响

目的探讨板蓝根抗内毒素活性部位F022对脂多糖(LPS)刺激鼠单核细胞释放炎性细胞因子的影响。方法取BALB/C小鼠腹腔内单核细胞,实验设计为6组。其中,实验组根据F022浓度分为1%、0.5%、0.25%、0.125%4组,分别加入板蓝根F022部位液后再加入LPS液;LPS阳性组仅加入LPS液;阴性组加入1%F022液。之后检测细胞培养上清液中3种炎性细胞因子肿瘤坏死因子-α(TNF-α)、白细胞介素6(IL-6)和一氧化氮(NO)水平。结果LPS可刺激鼠单核细胞过度释放炎性细胞因子TNF-α、IL-6和NO;与阳性组比较,实验组炎性细胞因子水平降低,且呈剂量依赖性。结论板蓝根抗内毒素活性部位F022对LPS刺激鼠单核细胞过度释放炎性细胞因子具有抑制作用。     

玉竹提取物A对1型糖尿病小鼠血糖及细胞因子的调控作用

目的:研究1型糖尿病(DM)的发生与细胞因子作用的关系及玉竹提取物A(EA-PAOA)对链脲佐菌素(STZ)诱导的1型糖尿病小鼠(下称STZ小鼠)血糖和细胞因子的影响。方法:昆明小鼠60只,对EA-PAOA进行急性毒性实验。采用STZ小剂量多次注射诱导1型糖尿病小鼠模型,正常对照组与DM对照组各1组,实验组分三个剂量腹腔注射等体积EA-PAOA,用药4周监测血糖变化,4周后应用EL ISA法检测外周血血清IL-4、IL-10、IFN-γ含量。结果:急性毒性实验显示EA-PAOA毒性作用很低,LD 50=14.5124g/K g;DM对照组与正常对照组比较IL-4、IL-10降低,IFN-γ升高;实验组与DM对照组比较血糖明显降低,IL-4、IL-10升高,IFN-γ降低。结论:1型DM的发生与细胞因子IL-4、IL-10降低,IFN-γ升高有关,EA-PAOA安全范围大,可调节STZ小鼠发病过程中细胞因子水平,干预1型DM发生发展。     

Rab26对TLR4介导的ARDS的作用及机制研究

目的 探讨Rab26对TLR4所介导的急性呼吸窘迫综合征的作用及机制研究。方法 实验选用健康野生级C57小鼠及敲除基因鼠（Rab26-/-），构建对照组（正常野生型C57小鼠+气管内滴注5 mg/kgLPS,n=10）、实验组（敲除基因鼠+气管内滴注5 mg/kg LPS,n=10），观察6 h后各小组小鼠经腹主动脉取动脉血进行血气分析并处死小鼠；酶联免疫吸附法检测血清炎性因子TNF-α、IL-6;留取小鼠肺组织称重计算肺干湿比（W/D比值）；肺组织HE染色后做病理切片观察各组小鼠肺组织病理变化，并对肺损伤组织进行评分。结果 在构建肺损伤模型后6 h，与对照组相比，实验组小鼠氧合指数、血清炎性因子TNF-α、IL-6水平明显下降(P<0.01)；实验组小鼠肺组织的W/D值明显更高（P<0.01）；病理切片结果 显示，实验组小鼠肺组织破坏更重，肺泡壁充血水肿、肺泡萎陷不张更为显著，肺损伤评分明显高于对照组(P<0.01)。结论 Rab26对TLR4所介导的ARDS炎性因子表达，以及激活下游信号通路有抑制作用，为将来急性肺损伤诊治的方向和重点进一步提供了研究依据。     

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.     

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.     

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.