枝管藻多糖对实验性高脂血大鼠血脂和过氧化水平的影响

目的:观察枝管藻多糖对实验性高脂血大鼠血脂和过氧化水平的影响。方法:以Wistar大鼠为研究对象,用高脂饲料建立高脂血症大鼠模型,分别ig枝管藻多糖和烟酸肌醇酯(枝管藻多糖的剂量为150mg·kg~(-1)·d~(-1),300mg·kg~(-1)·d~(-1),烟酸肌醇酯的剂量为 100mg·kg~(-1)·d~(-1)),连续40d。于实验的第 30天和第40天,各采血一次,分别测定血清 TC,TG,LDL-C,HDL-C,MDA,ROS含量和 SOD活性。结果:枝管藻多糖能显著抑制们喂高脂饲料大鼠的 TG(P<0.05)水平的升高,显著降低高脂血症大鼠的血清 TC(P<0.05)和TG(P<0.05)含量,但对血清LDL-C和HDL-C含量的变化几乎无影响;明显降低高脂血大鼠血清ROS,MDA含量,提高血清 SOD活性(P<0.01或 P<0.05)。结论:枝管藻多糖能够显著改善高脂血大鼠体内过氧化状态,但其抗高脂血效果低于烟酸肌醇酯。     

茶多酚对奥氮平诱导肥胖大鼠的减肥作用及其机制

目的探讨茶多酚对奥氮平诱导肥胖大鼠的减肥作用及其机制。方法 SD雌性大鼠50只,随机分为正常对照组(10只)和奥氮平诱导肥胖模型组(40只)。肥胖模型组于黑暗时相前1h奥氮平1.2 mg·kg~(-1)·d~(-1)灌胃,正常对照组给予等容量蒸馏水,连续2 wk。于wk 3开始,再将肥胖模型大鼠随机分为4组:模型组、西布曲明(2.5 mg·kg~(-1)·d~(-1))组、茶多酚低(150 mg·kg~(-1)·d~(-1))剂量组和茶多酚高(300 mg·kg~(-1)·d~(-1))剂量组,每组10只。连续给药5 wk。观察大鼠体重、肾和子宫周围脂肪湿重,计算Lee's指数和脂肪系数,测定血清瘦素、脂联素水平以及超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。结果与正常对照组相比,模型组大鼠体重和脂肪湿重及Lee's指数和脂肪系数均增加,血清瘦素水平升高,脂联素水平降低(P<0.05)。与模型组比较,茶多酚低、高剂量组大鼠体重和脂肪湿重降低,Lee's指数、脂肪系数降低,SOD活性增加,MDA含量减少(P<0.05)。与模型组比较,茶多酚高剂量组血清脂联素水平升高(P<0.05),瘦素水平无显著差异(P>0.05)。结论茶多酚对奥氮平诱导的肥胖大鼠有减肥作用,其作用机制可能与增强脂联素的调节和提高抗氧化能力有关。     

荆花胃康胶丸对溃疡大鼠胃黏膜NO,NOS和ET含量的影响

目的:观察荆花胃康胶丸对溃疡大鼠胃黏膜内皮素(ET)、一氧化氮(NO)、一氧化氮合酶(NOS)含量的影响。方法:采用Okabe氏法造成大鼠胃溃疡模型,随机将模型动物分为蒸馏水对照组、荆花胃康胶丸30,20, 10 mg·kg~(-1)·d~(-1)组、硫糖铝10 mg·kg~(-1)·d~(-1)及法莫替丁5 mg·kg~(-1)·d~(-1)组,每组8只。各组均灌胃给药,qd,连续10 d。末次给药后次日,测定各组溃疡面积,并测定溃疡周围组织NO,NOS及ET含量。结果:与对照组相比,荆花胃康胶丸30,20,10 mg·kg~(-1)·d~(-1)组的溃疡面积显著降低,溃疡周围组织NO及NOS的含量明显增高,ET的含量明显降低(P＜0．01),且呈现剂量依赖性;荆花胃康胶丸30 mg·kg~(-1)·d~(-1)组的保护作用优于硫糖铝及法莫替丁组(P＜0．05)。结论:荆花胃康胶丸可能通过增加胃溃疡组织NO及NOS的含量及降低ET的含量来发挥胃黏膜修复作用。     

Kappa-晒化卡拉胶对实验动物的抗心律失常作用

Kappa-硒化卡拉胶是一含硒有机化合物。ip 9 mg·kg~(-1)·d~(-1)×5d或单次ig 35,70,140mg·kg~(-1)能显著提高乌头碱致大鼠HA的阈剂量,此作用可与Na_2SeO_3 1 mg·kg~(-1)·d~(-1)×5d ip比拟.随着Kappa-硒化卡拉胶ig剂量增加,尚可提高乌头碱所致VE,VT和VF的阈剂量。ip 9mg·kg~(-1)·d~(-1)×5 d或ig 70mg·kg~(-1)能提高BaCl_2致大鼠或哇巴因致豚鼠HA的阈剂量。对BaCl_2致大鼠VF或哇巴因致豚鼠VE的阈剂量,分别在ig70mg·kg~(-1)与140mg·kg~(-1)时有提高,而ipNa_2SeO_3 1 mg·kg~(-1)·d~(-1)×5d无此明显影响。     

2-巯基苯并咪唑SD大鼠灌胃给药的毒性研究

目的:研究2-巯基苯并咪唑(MBI)对 SD 大鼠所产生的毒性反应的性质和程度、剂量和毒性效应的关系、无毒反应剂量以及毒性的主要靶器官。方法:采用 SD 大鼠,灌胃给予 MBI,分为溶媒对照组和3个给药组(MBI 2 mg·kg~(-1),MBI 10 mg·kg~(-1),MBI 50 mg·kg~(-1)),连续给药28 d,期间对体重、摄食量进行监测。给药结束次日解剖取材,测定血液学及血清生化学指标,并对大鼠主要脏器进行大体观察和组织病理学检查。结果:50 mg·kg~(-1)MBI 使大鼠的体重增长及摄食量的增加受到明显抑制;10 mg·kg~(-1)和*或50 mg·kg~(-1)MBI 导致雌雄大鼠甲状腺、脑、肝脏重量明显升高,胸腺、脾脏重量显著下降;使雄性大鼠垂体、肺、睾丸重量明显升高,雌性肾上腺、颚下腺重量显著下降,肾脏重量显著升高;50 mg·kg~(-1)剂量引起大鼠 AST、LDH、CRE、BUN、CHO 等血清生化水平的显著变化;组织病理学检查发现,10 mg·kg~(-1)以上剂量的 MBI 可引起雄性和雌性动物甲状腺增生性病变、垂体前叶β细胞肿胀以及雄性动物胸腺萎缩;50 mg·kg~(-1)MBI 可引起雄性和雌性动物肝损伤,肾上腺皮质细胞的脂肪变性,以及雌性动物肾盂扩张。结论:MBI 毒性作用的主要靶器官为甲状腺;MBI 在 SD 大鼠的最大无毒反应剂量为2 mg·kg~(-1)。     

硝酸铋预处理对顺铂肾毒性的防护作用

大鼠预先sc硝酸铋(30μmol·kg~(-1)·d~(-1))连续3d,可显著降低肾毒性剂量顺铂(5mg·kg~(-1))引起的尿蛋白含量,尿NAG活性和BUN水平的升高;并可有效地防护顺铂造成的肾脏髓层外带近端小管坏死,铋对肾脏MT合成有诱导作用,这可能与其防护顺铂的急性肾毒性有关。     

nobiliside A隐形纳米脂质体对小鼠RM-1前列腺癌的抑制作用

目的比较nobiliside A隐形纳米脂质体(NASNL)和nobiliside A普通脂质体(NACL)对小鼠RM-1前列腺癌的抑制作用。方法 RM-1前列腺癌荷瘤小鼠随机分为6组(均n=10):阴性对照组(生理盐水)、阳性对照组(环磷酰胺20 mg·kg~(-1)·d~(-1))、NACL低、高剂量组(1 mg·kg~(-1)·d~(-1)、2 mg·kg~(-1)·d~(-1))和NASNL低、高剂量组(1 mg·kg~(-1)·d~(-1)、2 mg·kg~(-1)·d~(-1)),均尾静脉注射给予相应药物,连续7 d。通过比较各组小鼠的肿瘤生长曲线、抑瘤率、肿瘤组织的病理变化等考察2种脂质体的抑瘤效果。结果 NASNL两剂量组的肿瘤生长速度均低于相应剂量的NACL组(P<0.05)。NASNL两剂量组的抑瘤率均高于相应的NACL组,其中NASNL高剂量组的抑瘤率是NACL高剂量组的2倍。NASNL各组肿瘤细胞坏死程度高于NACL各组。结论 NASNL的肿瘤抑制作用明显优于NACL。     

赛庚啶对异丙肾上腺素诱发整体大鼠心肌损伤的保护作用

异丙肾上腺素(Iso,4mg·kg~1·d~1×2 d,sc)可使整体大鼠心电图J点明显抬高,血清磷酸肌酸激酶活性和游离脂肪酸含量显著增加,心肌组织超氧化物歧化酶和谷胱甘肽过氧化物酶活性明显降低,但心肌组织丙二醛含量无明显改变.等剂量的赛庚啶(Cyp)和维拉帕米(2mg·kg~(-1)·d~1×2d,iv)均能有效地保护Iso所致的整体大鼠心肌损伤,其作用强度相近,提示Cyp对Iso诱发心肌损伤的保护作用可能主要与其抑制细胞Ca~(2+)内流和抗氧自由基作用有关     

葛根素对D-半乳糖诱导糖基化模型大鼠血糖和肝肾功能的影响

目的:研究葛根素(puerarin)对D-半乳糖诱导的糖基化模型大鼠血糖、胰岛素敏感指数和肝、肾功能的影响。方法:D-半乳糖(150 mg·kg~(-1)·d~(-1),ip)给药8周,诱导糖基化模型大鼠,并于第3周开始给予葛根素高、中、低剂量(300,150,75 mg·kg~(-1)·d~(-1))处理6周。测定红细胞醛糖还原酶活性、糖化血红蛋白、血清果糖胺和晚期糖基化终末产物(advanced glycation end-products,AGEs)含量,以及血糖、血清胰岛素水平和肝脏、肾脏功能的影响。结果:葛根素高、中剂量能够明显降低D-半乳糖引起的模型大鼠血糖升高,增加胰岛素敏感指数,降低红细胞醛糖还原酶的活性,并显著抑制糖基化产物的形成(P＜0．01);显著降低血清肌酐、尿素氮的含量(P＜0．01或P＜0．05)。结论:葛根素具有抑制D-半乳糖诱导的糖基化反应,恢复胰岛素敏感性,并对糖基化诱致的肝脏和肾脏功能损伤具有保护作用。     

N-乙酰半胱氨酸对肺间质纤维化大鼠肺损伤及外周血单核细胞DNA损伤的保护作用

目的观察肺间质纤维化大鼠氧化-抗氧化状态、外周血单核细胞(PBMCs)DNA损伤情况和N-乙酰半胱氨酸(NAC)的保护作用及其机制。方法气管内灌注博来霉素建立大鼠肺纤维化模型,设正常对照组、模型组、NAC小剂量组(NAC 50mg·kg~(-1)·d~(-1))、NAC大剂量组(NAC 200mg·kg~(-1)·d~(-1))和氢化可的松组(氢化可的松100mg·kg~(-1)·d~(-1)),每组18只。于给药后d7、14、28,观察各组肺组织病理学改变和羟脯氨酸(HYP)、丙二醛(MDA)以及谷胱甘肽过氧化物酶(GSH-Px)含量及PBMCs DNA损伤情况。结果与正常对照组比较,模型组肺泡腔、肺间质均可见大量胶原纤维和成纤维细胞。给药后d28,NAC组肺泡炎和肺纤维化程度均较模型组改善(P<0.05)。模型组肺组织HYP、MDA和PBMCs彗星率高于正常对照组,GSH-Px低于正常对照组(P<0.01)。与模型组比较,NAC大、小剂量组鼠肺组织HYP和MDA水平降低、GSH-Px含量升高、PBMCs彗星率降低,差异均非常显著(P<0.01)。结论 NAC能减轻博来霉素诱导的大鼠肺纤维化,这种作用有可能是通过改善体内氧化应激状态、减轻PBMCs DNA损伤实现的。     

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.     

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.