秦皮甲素通过调节TLR/NF-κB途径抑制脂多糖诱导的心肌损伤

目的 研究秦皮甲素对脂多糖（lipopolysaccharide，LPS）诱导大鼠心肌损伤及TLR/NF-κB途径的影响。方法 构建LPS诱导心肌损伤模型，将大鼠分为对照组、LPS组、秦皮甲素低剂量组（20 mg·kg^-1）、秦皮甲素中剂量组（40 mg·kg^-1）、秦皮甲素高剂量组（80 mg·kg^-1）和阳性对照组（地塞米松2 mg·kg^-1）。心脏超声检测心脏功能，HE染色检测心脏组织损伤程度。ELISA检测血液中肌钙蛋白（cardiac troponin I，cTnI），肌酸激酶同工酶[creatine kinase （CK）-MB，CK-MB]，肌红蛋白（myoglobin，Mb），肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α），白介素-6（interleukin-6，IL-6），IL-1β，丙二醛（malondialdehyde，MDA），超氧化物歧化酶（superoxide dismutase，SOD）和髓过氧物酶（myeloperoxidase，MPO）的含量。Western blotting检测Toll样受体2（Toll-like receptor 2，TLR2），TLR4，骨髓分化因子88（myeloid differentiation factor 88，MyD88），白介素1受体相关激酶（interleukin-1 receptor-associated kinases，IRAK1）和磷酸化核因子-κB （phosphorylated-nuclear factor-κB，p-NF-κB）的蛋白相对表达量。结果 与LPS组相比，在秦皮甲素治疗后，心率、左室壁相对厚度和左心室射血分数均显著升高（P<0.05），而左室收缩末容积显著降低（P<0.05）。心肌酶cTnI、CK-MB和Mb的表达量显著下调（P<0.05）；促炎细胞因子IL-6、TNF-α和IL-1β的表达量下调（P<0.05）；氧化应激标记物中SOD含量显著升高（P<0.05），而MDA和MPO含量均显著降低（P<0.05）；TLR2、TLR4、MyD88、IRAK1和p-NF-κB蛋白表达水平均显著下调（P<0.05）。结论 秦皮甲素对LPS诱导心肌损伤具有保护作用，并抑制TLR/NF-κB信号通路。     

姜黄素抑制HMGB1-NF-κB信号通路减轻脂多糖诱导新生大鼠急性肺损伤实验研究

目的 分析姜黄素抑制高迁移率族蛋白B1（HMGB1）-核转录因子κB（NF-κB）信号通路减轻脂多糖（LPS）诱导新生大鼠急性肺损伤（ALI）的作用。方法 将60只新生SD雄性大鼠随机分为对照组、模型组、地塞米松（阳性药,2 mg·kg^-1）组和姜黄素低、中、高剂量（1.5、3.0、6.0 mg·kg^-1）组,每组10只。除对照组外,所有大鼠采用腹膜内注射LPS （3 mg·kg^-1）建立ALI模型。注射LPS约6 h后开始ip给药,每天1次,连续7 d,模型组和对照组大鼠ip等体积的0.1% DMSO。通过血氧分压（PaO₂）和肺干湿质量比（W/D）评估新生大鼠肺水肿情况;HE染色检测各组大鼠肺组织损伤;ELISA法检测新生大鼠支气管肺泡灌洗液（BALF）氧化应激指标超氧化物歧化酶（SOD）、髓过氧化物酶（MPO）、丙二醛（MDA）和谷胱甘肽（GSH）水平,BALF中白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）和HMGB1水平;Western blotting法检测大鼠肺组织胞核NF-κB、胞浆NF-κB和磷酸化核因子κB抑制因子α（p-IκBα）蛋白表达。结果 与对照组相比,模型组新生大鼠肺泡腔有渗出、肺组织结构紊乱、细胞核固缩深染、伴随大量的炎性细胞浸润,病理评分显著升高（P<0.01）; PaO₂、BALF中SOD和GSH水平显著降低（P<0.01）;肺W/D,BALF中MPO和MDA水平,BALF中IL-6、TNF-α和HMGB1水平,NF-κB胞核/胞浆比例和胞浆p-IκBα蛋白表达水平显著升高（P<0.01）。与模型组相比,姜黄素高、中剂量组和地塞米松组大鼠肺组织病理损伤减轻,肺泡腔渗出、炎性细胞浸润明显减少,病理评分显著降低（P<0.05、0.01）; PaO₂、BALF中SOD和GSH水平显著升高（P<0.05、0.01）;肺W/D,BALF中MPO、MDA水平,BALF中IL-6、TNF-α和HMGB1水平,NF-κB胞核/胞浆比例和胞浆p-IκBα蛋白表达水平显著降低（P<0.05、0.01）。结论 姜黄素可以通过抑制HMGB1-NF-κB信号通路减轻LPS诱导的新生大鼠ALI。     

芪丹复感颗粒对呼吸道病毒感染小鼠TLRs信号通路的影响

目的 探究芪丹复感颗粒对呼吸道病毒感染小鼠肺组织的保护作用及对TLRs信号通路的影响。方法 120只小鼠随机分为对照组,模型组,阳性药组（利巴韦林100 mg·kg^-1）,芪丹复感颗粒低、中、高剂量组（芪丹复感颗粒1,2,4 g·kg^-1）,每组20只,其中12只用于观察死亡情况。除对照组外,其余各组小鼠均通过鼻饲流感病毒PR8建立流感病毒感染模型。通过HE染色观察肺组织形态,ELISA检测小鼠血清和肺泡灌洗液（bronchoalveolar lavage fluid,BALF）中肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）的浓度。分别使用Western blot和RT-qPCR检测Toll样受体4/7（TLR4/7）、髓样分化因子（MyD88）、核因子κB（NF-κB）蛋白表达和mRNA水平。结果 建模第7天,模型组小鼠全部死亡,死亡率为100.0%。在建模后第14天阳性药组死亡3只（25.0%）,芪丹复感颗粒低、中、高剂量组分别死亡9只（75.0%）、6只（50.0%）和5只（41.7%）。造模第5天,模型组,阳性药组,低、中、高剂量组的血清和BALF中的TNF-α、IL-6、IL-1β水平以及肺组织中TLR4/7、MyD88、NF-κB蛋白表达和mRNA水平均显著高于对照组（P<0.05）,阳性药组,低、中、高剂量组均显著低于模型组（P<0.05）,中、高剂量组显著低于低剂量组（P<0.05）,而中、高剂量组之间无显著差异。结论 芪丹复感颗粒可以减轻流感病毒造成的肺损伤,可能是通过抑制TLR4/7-MyD88-NF-κB通路的表达抑制炎症因子的释放,从而降低肺损伤。     

柚皮苷通过减轻氧化应激降低急性肺损伤小鼠内皮通透性的研究

目的 研究柚皮苷对脂多糖（LPS）诱导的小鼠急性肺损伤模型肺微血管内皮通透性及气道炎症的改善作用。方法 将66只C57BL/6雄性小鼠随机分为对照组、模型组、地塞米松组及柚皮苷40、80、120 mg/kg组,每组11只。对照组小鼠正常饲养;模型组和给药组小鼠麻醉后给予LPS滴鼻,每只小鼠滴鼻50 μL。柚皮苷40、80、120 mg/kg组和地塞米松5 mg/kg组在LPS滴鼻前分别ig相应剂量的柚皮苷和地塞米松,连续给药5 d,滴鼻后继续ig相应剂量的柚皮苷和地塞米松,连续给药2 d。对照组和模型组同时间ig 0.2 mL生理盐水。苏木精–伊红（HE）染色观察肺实质病理变化;血常规分析仪检测血液及肺泡灌洗液淋巴细胞、中性粒细胞、血细胞、血小板数量;ELISA检测肺泡灌洗液白细胞介素（IL）-1β、IL-6、肿瘤坏死因子-α（TNF-α）含量和血清内皮素-1（ET-1）水平;肺组织伊文思蓝成像分析肺泡–血管通透性,qPCR检测紧密连接蛋白紧密连接蛋白-1（ZO-1）、密封蛋白（OCLN）、血管内皮钙黏素（VE-cadherin）、β-连环蛋白（β-catenin）和水通道蛋白AQP1、AQP5的mRNA表达水平;化学分析法检测血清丙二醛（MDA）、超氧化物歧化酶（SOD）、一氧化氮（NO）水平。结果 与模型组相比,柚皮苷120 mg/kg组能够显著改善LPS诱导的急性肺损伤小鼠肺水肿及肺组织炎症浸润的病理状态,减少肺泡内炎症细胞数量、炎症因子和总蛋白含量,以及肺组织伊文思蓝渗入量;增强紧密连接蛋白和水通道蛋白表达;减缓血液炎症细胞流失,降低血管氧化应激水平（P＜0.05）。结论 柚皮苷能够减轻LPS诱导的气道炎症,并可能通过降低血管氧化应激水平减少对紧密链接蛋白和水通道蛋白的损害作用从而改善肺内皮高通透性。     

红景天苷介导TLR4调控小胶质细胞激活对小鼠抑郁样行为的改善作用

目的 探讨红景天苷对脂多糖（LPS）诱导炎症抑郁模型小鼠的作用及机制。方法 48只Balb/c小鼠随机分为对照组、模型组、盐酸氟西汀（阳性药,20 mg/kg）组、红景天苷（25 mg/kg）组,每组12只。各组连续ig给药14 d后,除对照组外,其余各组ip 1 mg/kg LPS连续7 d制备抑郁症模型。以糖水偏好实验、旷场实验、悬尾实验和强迫游泳实验检测小鼠抑郁样症状;结束后取脑组织与血液检测肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）水平;Iba1免疫荧光染色检测脑组织小胶质细胞激活;Western blotting法检测脑组织TLR4信号通路蛋白TLR4、NLRP3、cleaved-Caspase-1/Caspase-1表达。结果 与模型组比较,红景天苷与盐酸氟西汀预防给药能够显著上调小鼠糖水摄取率（P<0.05）,增加小鼠穿格评分（P<0.05）,下调悬尾与强迫游泳不动时间（P<0.05）;显著逆转LPS造成的TNF-α、IL-1β水平上调（P<0.05）;明显抑制小胶质细胞激活,显著降低Iba1荧光强度（P<0.05）;显著降低脑组织中TLR4、NLRP3与cleaved-Caspase-1/Caspase-1蛋白表达（P<0.05）。结论 ip LPS成功构建了炎症诱导的抑郁模型,红景天苷通过TLR4信号通路调控小胶质细胞激活,从而改善小鼠抑郁样行为。     

大黄素通过调控TLR4/NF-κB通路对脂多糖诱导血管内皮细胞氧化损伤的保护作用研究

目的 研究大黄素对脂多糖（LPS）诱导人脐静脉血管内皮细胞（HUVEC）氧化损伤的保护作用及机制。方法 运用CCK-8细胞活力检测法筛选LPS体外诱导HUVEC细胞氧化损伤模型浓度及大黄素给药浓度。取HUVEC细胞,分为对照组、模型组（1 μg/L LPS）、吡咯烷二硫代氨基甲酸铵（PDTC,阳性药,10 μmol/L）组和大黄素低、高剂量（40、80 μmol/L）组,置于37℃、5% CO₂培养箱中培养24 h。ELISA法测定各组细胞上清液中一氧化氮（NO）、丙二醛（MDA）、活性氧（ROS）、肿瘤坏死因子-α（TNF-α）的含量;采用Western Blotting法检测各组细胞中Toll样受体（TLR4）、核因子κB（NF-κB p65）、TNF-α蛋白的表达。结果 LPS浓度为1 μg/L,作用24、48 h,HUVEC细胞存活率分别为64.8%、51.2%; 40、80 μmol/L大黄素作用24、48 h对HUVEC细胞存活率无显著影响,选择1 μg/L作为LPS造模浓度,40、80 μmol/L作用24 h作为大黄素给药条件。与对照组比较,模型组HUVEC细胞增殖活力显著下降,NO、MDA、ROS、TNF-α含量显著升高,TLR4、NF-κB p65、TNF-α蛋白表达升高（P<0.01）;与模型组比较,40、80 μmol/L大黄素给药后HUVEC细胞生存率显著升高,NO、MDA、ROS、TNF-α含量显著降低,TLR4、NF-κB p65、TNF-α蛋白表达显著降低（P<0.05、0.01）。结论 大黄素对LPS诱导的HUVEC细胞氧化损伤具有显著保护作用,其作用机制可能与调控TLR4/NF-κB通路、抑制炎症有关。     

甘草酸单铵对脂多糖致小鼠急性肺损伤的保护作用

采用脂多糖(lipopolysaccharide，LPS)气道滴入诱导小鼠急性肺损伤(acute lung injury，ALI)模型，研究甘草酸单铵(monoammonium glycyrrhizinate，MAG)对ALI的防治作用及其机制。雄性ICR小鼠随机分为生理盐水(NS)对照组、MAG 3、10 及30 mg·kg^-1组、LPS组、地塞米松(dexamethasone，DXM) 5 mg·kg^-1组。MAG各组气道滴入LPS前1 h及滴入后3 h各给药1次，DXM组气道滴入LPS前1 h给药1次。LPS气道滴入后6 h处死动物，测定各组的肺湿重/干重比、肺通透性、肺组织中性粒细胞髓过氧化物酶(myeloperoxidase，MPO)含量、ELISA法检测肺组织匀浆TNF-α、IL-10含量，常规细胞形态学检测中性粒细胞在支气管肺泡灌洗液(bronchoalveolar lavage fluid，BALF)中的比例和肺组织病理改变。结果表明，MAG剂量依赖性减轻气道内滴入LPS诱导的小鼠ALI程度，降低肺湿重/干重比及肺组织伊文斯蓝的渗出，降低BALF中白细胞总数和中性粒细胞数比例，抑制组织MPO的释放，降低肺组织匀浆TNF-α的含量，增加肺组织IL-10的释放。以上结果提示，MAG可能通过调节TNF-α/IL-10的平衡而有效保护脂多糖诱导的急性肺损伤。     

银杏叶提取物注射液对脂多糖致大鼠急性肺损伤肺组织的保护作用

目的 观察银杏叶提取物注射液（GBE）对脂多糖（LPS）致大鼠急性肺损伤（ALI）肺组织的保护作用及其可能机制。方法 24只健康雄性Wistar大鼠随机分为对照组、LPS组和GBE组,每组8只。尾静脉注射LPS建立ALI模型,光镜下观察大鼠肺组织形态学改变;检测肺组织中超氧化物歧化酶活性（SOD）和丙二醛（MDA）含量及血清中白细胞介素-6（IL-6）的表达变化。结果 与对照组相比,LPS组肺组织中SOD活性降低、MDA含量增加、血清中IL-6含量增加（P<0.05）;应用GBE后,肺组织SOD活性升高、MDA含量减少、血清中IL-6含量减少（P<0.05）。结论 GBE可有效减轻ALI肺组织的炎症反应,其机制可能与其提高大鼠抗氧化能力、升高血清中IL-6的含量有关。     

注射用益气复脉（冻干）联合顺铂对乳腺癌荷瘤小鼠的抗肿瘤作用研究

目的 观察并探讨注射用益气复脉（冻干）（YQFM）联合顺铂对乳腺癌荷瘤小鼠的抗肿瘤作用。方法 接种4T1肿瘤细胞悬液0.1 mL （细胞总数约1×10⁷）于SPF级BALB/C小鼠第4对乳头下方的皮下脂肪垫制备乳腺癌模型。造模小鼠随机分为模型组、顺铂（1 mg/kg）组、YQFM（914 mg/kg,临床等效剂量）组、1/2顺铂（0.5 mg/kg）＋YQFM（914 mg/kg）组、顺铂（1 mg/kg）＋YQFM（914 mg/kg）组,各组小鼠均于接瘤后第7天开始给药,顺铂均ip给药,隔天给药1次,共7次;YQFM均尾iv给药,每天1次,共14 d。模型组同法给予9%氯化钠注射液。观察小鼠生活状态、体质量变化;检测实体瘤质量并计算抑瘤率;测量瘤体积变化;ELISA法检测各组小鼠血清白细胞介素-2 （IL-2）、白细胞介素-4 （IL-4）、γ-干扰素（IFN-γ）、乳酸脱氢酶（LDH）和肿瘤坏死因子-α （TNF-α）、腺嘌呤核苷三磷酸（ATP）水平。结果 与模型组比较,顺铂组、顺铂＋YQFM、1/2顺铂＋YQFM组小鼠从顺铂第3次给药左右开始出现毛发稀疏、掉毛严重、发呆、行动迟缓、喜抱团等现象,1/2顺铂＋YQFM组比单纯顺铂组稍好。与模型组比较,YQFM组体质量显著增加（P<0.05、0.001）;顺铂组体质量增长显著减缓（P<0.05、0.001）; 1/2顺铂＋YQFM组和顺铂＋YQFM组2组小鼠体质量无显著性差异。与模型组比较,顺铂组、1/2顺铂＋YQFM组及顺铂＋YQFM组瘤质量均显著减轻（P<0.05）,YQFM＋顺铂组的抑瘤率最佳,1/2顺铂+YQFM组与顺铂组抑瘤效果相当。与模型组比较,顺铂＋YQFM组、顺铂组、1/2顺铂＋YQFM组分别是在给药后第7、9、11天时瘤体积出现显著降低（P<0.05）。与模型组比较,顺铂组、1/2顺铂＋YQFM组及YQFM＋顺铂均能够显著提高IL-2、IL-4、IFN-γ、TNF-α水平和降低ATP的含量（P<0.01、0.001）;顺铂组和1/2顺铂＋YQFM组的LDH含量显著提高（P<0.05）; YQFM也能显著性提高IL-2、IFN-γ、TNF-α含量和降低ATP的含量水平（P<0.01、0.001）。与顺铂组比较,1/2顺铂＋YQFM组的TNF-α含量显著降低（P<0.01）。结论 YQFM与顺铂联合使用对乳腺癌荷瘤小鼠具有一定的增效协同作用。     

哮喘宁颗粒联合布地奈德福莫特罗治疗支气管哮喘急性发作期的临床研究

目的 探讨三子养亲汤（SZ）对大鼠实验性支气管哮喘的保护作用及潜在机制。方法 以卵清蛋白（OVA）致敏和激发诱发支气管哮喘,将大鼠随机分为5组：对照组、模型组、地塞米松（阳性药,1 mg/kg）组、SZ治疗（200 mg/kg）组和SZ单给药（不造模,200 mg/kg）组。试剂盒法检测血清免疫球蛋白E（IgE）水平。ELISA试剂盒法检测支气管肺泡灌洗液（BALF）中的炎性生物标志物白细胞介素（IL）-4、IL-5、IL-13、肿瘤坏死因子-α（TNF-α）、γ-干扰素（IFN-γ）;Dunger''s稀释液染色法进行BALF中嗜酸性粒细胞计数;试剂盒法检测BALF中氧化氮应激生物标记物丙二醛（MDA）和谷胱甘肽（GSH）水平、超氧化物歧化酶（SOD）的活性;实时荧光定量PCR法检测BALF中诱导型一氧化氮合酶（iNOs）RNA水平。以Western blotting法检测肺匀浆中肺表面活性蛋白-D（SP-D）表达水平;免疫组化测定肺中尿皮质素（UCN）的表达。HE染色法观察大鼠肺组织病理学变化。结果 与模型组比较,SZ治疗可显著降低血清IgE水平（P<0.05）;显著降低BALF中MDA含量,同时显著提高SOD活性和GSH含量（P<0.05）;显著降低BALF中IL-4、IL-5、IL-13、IFN-γ和TNF-α水平（P<0.05）;显著降低肺组织中SP-D和UCN的蛋白表达（P<0.05）;HE染色结果表明,SZ显著改善模型大鼠肺组织炎症病变。结论 SZ可通过下调SP-D和UCN表达改善OVA诱导的支气管哮喘。     

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.