二氧化硫吸入对小鼠脾脏的氧化应激作用

目的　研究不同浓度二氧化硫 (SO2 )吸入后雌、雄小鼠脾脏脂质过氧化水平和抗氧化能力的变化。方法　染毒组小鼠每日接受 4hSO2 吸入染毒 ,剂量分别为 2 8、5 6、112和 168mg m3,持续 7d。对照组接受新鲜空气。用硫代巴比妥酸 (TBARS)染色法测定丙二醛 (MDA)含量 ,分光光度法测定谷胱甘肽 (GSH)含量 ,二硫代双硝基苯甲酸 (DTNB)直接法测定谷胱甘肽过氧化物酶 (GSH Px)活力 ,改进的抗坏血酸 (Vc)终止法测定超氧化物歧化酶 (SOD)活力。结果　(1)随着SO2 吸入浓度增加 ,雌雄小鼠脾脏内MDA含量增加 ,GSH Px、SOD活力降低 ,在较高浓度 (>112mg m3)时 ,差异有显著性 (P <0 0 5 ) ;(2 ) 2 8mg m3SO2 吸入使GSH含量显著升高 (P <0 0 5 ) ,但在高浓度 (168mg m3)时 ,其含量却显著下降。 (3 )SO2 吸入对雌雄小鼠脾脏的氧化损伤作用没有性别差异。结论　SO2 吸入浓度高于 112mg m3以上时引起小鼠脾脏脂质过氧化作用增强 ,抗氧化能力降低 ,且存在一定的剂量依赖关系 ,提示较高浓度SO2 对脾的毒作用与诱发小鼠体内产生过量自由基有关     

茶多酚对甲醛染毒小鼠肝脏损伤的保护作用

目的探讨茶多酚对甲醛诱导小鼠肝脏损伤的保护作用。方法清洁级昆明小鼠经甲醛(80 mg/m3)静式吸入染毒,并同时给予不同浓度的茶多酚(100、200和400 mg/kg·bw)灌胃保护,持续28 d。测定血清中总蛋白、白蛋白含量及丙氨酸转氨酶(ALT)活力和肝脏组织中超氧化物歧化酶(SOD)活力、谷胱甘肽(GSH)及丙二醛(MDA)含量,并进行分析。结果甲醛染毒能引起血清总蛋白(30.239±4.394)、白蛋白(10.360±2.568)降低,ALT活力(13.6091±3.931)升高、GSH含量(11.175±3.482)、SOD活力(198.214±21.008)降低,MDA含量(16.392±2.329)升高,与空白对照相比均具有统计学意义(P0.05);加入茶多酚干预后,在甲醛+茶多酚高浓度组,血清总蛋白(34.920±3.513)、白蛋白(15.660±1.770)升高,ALT活力(10.169±2.562)降低、GSH含量(15.265±4.330)、SOD活力(221.128±23.665)升高,MDA含量(10.606±1.858)降低,与甲醛染毒组比较均具有统计学意义(P0.05)。结论加入茶多酚进行干预后,在一定程度上对甲醛诱导的小鼠肝脏损伤有保护作用。     

虾青素对甲醛致雄性小鼠精子损伤的保护作用研究

目的探讨虾青素对甲醛诱导的雄性小鼠精子损伤的保护作用。方法 48只昆明种系雄性小鼠,按随机数字表法分为4组,即正常对照组、甲醛染毒模型组、虾青素高剂量组(80mg·kg-1·d-1)、低剂量组(20mg·kg-1·d-1)。连续染毒7d后,虾青素持续灌胃21d,处死小鼠,进行附睾精子计数、精子活动度及精子畸形率分析,睾丸组织行超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量测定。结果甲醛染毒组小鼠精子数量、活动度,睾丸组织SOD明显低于正常对照组(P<0.05),精子畸形率、MDA含量高于正常对照组(P<0.05)。虾青素高、低剂量组精子数量、活动度,睾丸组织SOD高于甲醛染毒组(P<0.05),精子畸形率、MDA含量低于甲醛染毒组(P<0.05)。结论虾青素对甲醛诱导的雄性小鼠精子损伤一定的保护作用,可改善甲醛染毒小鼠的精子数量、活动度,降低精子畸形率,其作用机制可能与提高睾丸组织SOD水平、降低MDA含量有关。     

超顺磁性四氧化三铁纳米粒子致小鼠肾毒性作用

目的探讨超顺磁性四氧化三铁纳米粒子(SPIONs)致小鼠肾毒性作用。方法 64只雌雄各半的健康ICR小鼠随机分为对照组、SPIONs(4.5、9.0和45.0) mg/kg·bw染毒组,以尾静脉注射的方式连续染毒30 d,染毒结束后计算小鼠肾脏系数,观察小鼠肾组织病理学切片,测定肾匀浆中肌酐(CRE)含量、尿素氮(BUN)含量、尿酸(UA)含量、超氧化物歧化酶(SOD)活力、谷胱甘肽过氧化物酶(GSH-Px)活力以及丙二醛(MDA)含量。结果各组小鼠肾脏系数差异无统计学意义(P0.05);组织病理学观察各SPIONs染毒组肾组织均可见不同程度组织损伤;肾功能指标中,与对照组相比,随着染毒剂量的增加CRE含量逐渐升高(P0.05),UA含量先升高后降低(P0.01),BUN含量差异无统计学意义(P0.05);氧化应激指标中,与对照组相比,GSH-PX活性随着染毒剂量的增加逐渐降低(P0.01),SOD活性和MDA含量逐渐升高(P0.01)。结论静脉注射亚急性染毒条件下,SPIONs可引起小鼠肾功能破坏及氧化损伤,具有一定的肾毒性作用。     

甲醛和三氯乙烯联合染毒对小鼠行为功能的影响

目的研究甲醛和三氯乙烯联合染毒对小鼠神经行为的影响,为评价室内装修材料中甲醛和三氯乙烯对人体健康的危害提供科学依据。方法通过Morris水迷宫实验筛选健康清洁级昆明小鼠108只(雌雄各半),按照3×3析因的要求进行随机分组,采用静式吸入染毒,将小鼠暴露于不同浓度的甲醛、三氯乙烯及其二者的混合气体中,每天2 h,连续14 d。染毒结束后,采用Morris水迷宫实验和旷场实验对小鼠进行神经行为学测试。结果 Morris水迷宫实验结果显示,在定位导航实验中,单独及联合染毒组小鼠逃避潜伏期随着训练次数的增多均呈缩短趋势、且随着染毒剂量的增加小鼠逃避潜伏期延长,训练天数、甲醛和三氯乙烯对小鼠逃避潜伏期的影响差异均有统计学意义(P<0.01),同时甲醛和三氯乙烯对小鼠逃避潜伏期的影响存在交互作用(P<0.05)。在空间探索实验中,甲醛和三氯乙烯单独及联合染毒均可致小鼠第一次跨越原平台位置的时间延长。二者联合染毒对小鼠第一次跨越原平台位置的时间和原平台象限游泳距离占总距离百分比的影响存在交互作用(P<0.05),且表现为协同。旷场实验结果显示,甲醛和三氯乙烯染毒致小鼠在中央区活动时间延长,站立次数下降,中央区活动距离占总距离百分比增大,二者对小鼠在旷场实验中的中央区活动时间、直立次数以及中央区活动距离占总距离百分比的影响均有交互作用(P<0.01),且表现为协同。结论甲醛和三氯乙烯能降低小鼠的学习记忆能力,影响神经行为表现,二者联合染毒具有一定的协同作用。     

苯肽胺酸28d经口染毒致小鼠脾脏和胸腺的氧化损伤

目的研究不同剂量苯肽胺酸28 d经口染毒对小鼠主要免疫器官脾脏和胸腺组织的氧化损伤作用。方法选用40只成年雄性Balb/c小鼠,随机分成4组,每组10只。分别为对照组,30、100和300 mg/kg苯肽胺酸剂量组,每天灌胃染毒,连续28 d。末次染毒24 h后,检测主要器官脏器系数,苏木素-伊红(HE)染色观察脾脏和胸腺组织病理学变化,分别测定脾脏和胸腺的丙二醛(MDA)含量、总超氧化物歧化酶(T-SOD)和谷胱甘肽过氧化物酶(GSH-Px)的活力。结果连续染毒28 d,苯肽胺酸300 mg/kg剂量组小鼠脾脏脏器系数与对照组相比明显增大(P0.01),且发生了病理改变。100和300 mg/kg剂量组小鼠脾脏MDA含量明显升高(P0.05),300 mg/kg剂量组小鼠胸腺GSH-Px活力明显降低(P0.05),脾脏和胸腺中T-SOD活力的改变没有统计学意义(P0.05)。结论连续染毒28 d,300 mg/kg苯肽胺酸对小鼠主要免疫器官脾脏和胸腺产生了不同程度的氧化损伤作用。     

光气致小鼠肺水肿及肝脏过氧化损伤的实验研究

目的　探讨小鼠光气染毒剂量与肺水肿形成的关系及其对肝脏的过氧化损伤。方法　 5 0只小鼠 ,雌雄各半 ,随机分为 5组。正常对照组小鼠放置染毒柜中 5min ,染毒组小鼠分别给予 3 2、3 9、46、5 3mg L的光气 (各 10只 ) ,染毒时间为 5min。染毒后 4h ,测定各组小鼠肺脏的湿干比、肝脏的丙二醛 (MDA)含量、总超氧化物歧化酶 (T SOD)活力及进行肝脏HE染色。结果　随着光气染毒剂量的增加 ,小鼠肺脏的湿干比增加 ;当染毒剂量为 3 2mg L ,肝脏的MDA含量[(2 10 3 1± 44 61) μmol g]和T SOD活力 [(3 2 5 1± 6 10 )U g]比正常组 [(15 7 2 1± 18 17) μmol g ,(2 2 3 8± 6 0 2 )U g]升高 (P <0 0 5 ) ;光镜下 ,光气染毒的肝组织肝细胞呈现空泡样变性。结论　光气染毒可造成小鼠肺水肿 ,引起肝脏过氧化损伤。     

不同价态锰对不同月龄大鼠脂质过氧化的影响

目的　研究不同价态锰染毒后对大鼠脑、肝和心肌内脂质过氧化(MDA)和超氧化物歧化酶(SOD)活力的影响。方法　大鼠经腹腔分别注射氯化锰(MnCl2 ·4H2 O ,Mn2 )和醋酸锰(C6 H9O6 Mn·2H2 O ,Mn3 ) ,按6mg kg剂量连续染毒1个月后,测定脑、肝和心肌组织中MDA含量和SOD活力。结果　(1)经Mn2 染毒后大鼠脑组织MDA含量与对照组相比,差异有显著性(P <0 0 5 ) ,而Mn3 染毒后只有18月龄大鼠脑组织MDA含量显著高于对照组(P <0 0 5 ) ;在肝组织MDA含量,Mn2 组与对照组相比,差异有显著性(P <0 0 5 )。(2 )经Mn2 、Mn3 染毒后18月龄和4月龄大鼠脑组织SOD活力显著低于对照组(P <0 0 5 ) ;经Mn2 染毒后,18月龄和4月龄大鼠肝SOD活力明显低于对照组(P <0 0 5 ) ;经Mn3 染毒后,18月龄大鼠肝SOD活力显著低于对照组(P <0 0 5 )。(3 )心肌组织MDA含量,SOD活力与对照组相比,差异均无显著性。结论　不同价态、不同剂量锰染毒不同月龄大鼠对其不同组织MDA含量和SOD活力的影响是不同的。     

氢水对小鼠辐射致氧化损伤的保护作用

目的探讨氢水对辐射小鼠抗氧化水平的影响。方法 60只KM小鼠随机分为对照组、单纯放射组和氢水组。对照组和单纯放射组经胃给予纯化水,氢水组给予氢水。γ线照射结束后取肝肺组织制成10%肝肺组织匀浆,检测肝肺组织中SOD、GSH-PX活力及MDA含量。结果单纯照射组照射后的肝肺组织SOD、GSH-PX活力与对照组比明显降低。MDA含量明显升高(P<0.05)。氢水组的SOD、GSH-PX活性升高,MDA含量明显降低(P<0.05)。结论氢水对小鼠因辐射引起的氧化损伤有保护作用,可能与氢水具有选择性抗氧化作用有关。     

附子汤对次声损伤的防护作用

目的研究附子汤对在8Hz、130dB的次声暴露下小鼠大脑的过氧化水平的影响效果。方法将60只BALB/c小鼠分为次声高剂量用药组,次声中剂量用药组,次声低剂量用药组,次声对照组与正常对照组。15d后测试小鼠大脑微结构的变化,谷胱甘肽过氧化物酶(GSH-PX)、超氧化物歧化酶(SOD)的活性以及丙二醛(MDA)的含量。结果次声对照组与正常对照组相比,GSH-PX活力和MDA含量明显升高(P<0.05),SOD活力略有提高(P>0.05)。三组次声用药组与次声对照组相比,GSH-PX与SOD活力明显提高(P<0.05),MDA含量明显降低(P<0.05)。结论在8Hz、130dB的次声暴露下可以导致小鼠脑皮质脂质的过氧化,附子汤可以提升小鼠身体内部的GSH-PX及SOD活力,从而可以清除过量的体内自由基,使得MDA的含量减少,降低了机体的不良反应。     

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.

---

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.