枸杞多糖对小鼠酒精性肝损伤的保护作用及机制研究

目的 研究枸杞多糖对小鼠酒精性肝损伤的保护作用及机制。方法 将小鼠随机分为对照组、模型组和枸杞多糖低、中、高剂量（75、150、300 mg/kg）组,第1~9天于每日13：00时分别ig给药,模型组和对照组给予等量双蒸水。第10~16天给药4 h后,枸杞多糖和模型组小鼠均ig 50%酒精20 mL/kg进行造模,对照组小鼠给予等量双蒸水。观察小鼠一般状态,末次ig酒精16 h后处死小鼠,检测肝脏指数;全自动生化分析仪检测血清中丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）、三酰甘油（TG）、总胆固醇（TC）水平;试剂盒法测定肝组织丙二醛（MDA）、还原型谷胱甘肽（GSH）、谷胱甘肽过氧化物酶（GSH-Px）、总超氧化物歧化酶（SOD）及炎性因子肿瘤坏死因子-α（TNF-α）、白介素-1β（IL-1β）的含量;HE染色观察肝组织病理变化。结果 与模型组比较,枸杞多糖各剂量组小鼠醒酒时间短,毛色有所改善,较活跃;各剂量组肝脏指数呈下降趋势,但不具有统计学意义;各剂量组血清ALT、AST、TC、TG均呈下降趋势,其中高、中剂量组ALT显著降低（P<0.05）,3个剂量组TG浓度均差异显著（P<0.01）;各剂量组小鼠肝脏MDA含量显著降低（P<0.05、0.01）,GSH、SOD水平显著升高（P<0.05、0.01）,GSH-Px水平升高但未表现出显著性差异;高、中剂量组小鼠肝脏TNF-α和IL-1β水平显著降低（P<0.05、0.01）。HE染色显示,与模型组比较,枸杞多糖各组肝组织破坏程度较轻。结论 枸杞多糖对于乙醇诱导的酒精性肝损伤具有一定的保护作用,作用机制可能与通过清除体内多余自由基、增强体内抗氧化能力以及减轻炎症反应相关。     

雷公藤多苷片对高脂小鼠血脂的影响

目的 研究雷公藤多苷片对高脂小鼠血脂的影响。方法 采用高血脂小鼠模型,通过小鼠尾静脉注射不同剂量（0.5,1.0,1.5 mg·kg^-1·d^-1）雷公藤多苷,测定不同时间段小鼠体质量和血清总胆固醇（total cholesterol,TC）、甘油三酯（totaltriglyceride,TG）、高密度脂蛋白胆固醇（high density lipoprotein cholesterol,HDL-C）、低密度脂蛋白胆固醇（low densitylipoprotein cholesterol,LDL-C）的含量及卵磷脂胆固醇酰基转移酶（lecithin cholesterol acyltransferase,LCAT）、肝脂酶（hepatic lipase,HL）和脂蛋白脂酶（lipoprotein lipase,LPL）的活性,研究雷公藤多苷对小鼠体质量、血脂代谢、动脉粥样硬化指数、肝脏LCAT水平等的影响。结果 给予高脂饲料后小鼠体质量和血脂显著升高（P<0.01）,动脉粥样硬化指数显著升高（P<0.01）,抗动脉粥样硬化指数显著下降（P<0.01）。注射雷公藤多苷能显著降低高血脂模型小鼠血清TC、TG和LDL-C,同时显著降低高脂饮食所导致的动脉粥样硬化指数升高。此外,雷公藤多苷片能显著提高血清LCAT水平和HL、LPL的活性。结论 雷公藤多苷片具有一定的降血脂功能,并能有效降低动脉粥样硬化的发生几率。     

余甘子鞣质对代谢相关脂肪性肝病小鼠脂质代谢及肠道菌群的调节作用

目的 研究余甘子Phyllanthus emblica L.鞣质对代谢相关脂肪性肝病（MAFLD）小鼠脂质代谢及肠道菌群的调节作用。方法 将C57BL/6小鼠随机分为对照组、模型组和余甘子鞣质低、高剂量（200、400 mg·kg^-1）组及非诺贝特（阳性药,50 mg·kg^-1）组,每组10只。对照组小鼠常规饲料喂养,其余各组小鼠均给予高脂饲料喂养,建立MAFLD小鼠模型;ig给予相应药物干预,对照组及模型组给予同体积生理盐水,每天1次,连续给药8周。处死小鼠,收集血液、肝脏、粪便。计算肝脏系数;HE染色法观察肝组织病理学变化;试剂盒法检测小鼠血清中丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、三酰甘油（TG）、总胆固醇（TC）含量;实时荧光定量PCR （qRT-PCR）及Western blotting法检测肝组织中固醇调节元件结合蛋白（SREBP-1）、脂肪酸合成酶（FASN）、乙酰辅酶A羧化酶（ACC） mRNA和蛋白表达量;PCR扩增法检测实验前后小鼠粪便双歧杆菌、乳酸杆菌的含量变化。结果 与模型组比较,低、高剂量余甘子鞣质干预后小鼠肝脏系数显著降低（P<0.05、0.01）,小鼠肝组织脂肪变程度减轻;小鼠血清中ALT、AST、TG、TC水平均显著降低（P<0.05、0.01）;肝组织中SREBP-1、FASN、ACC mRNA和蛋白水平均显著降低（P<0.05、0.01）;粪便中双歧杆菌、乳酸杆菌的含量显著升高（P<0.01）。结论 余甘子鞣质能够通过SREBP-1/FASN/ACC通路调节脂质代谢、改善肠道菌群平衡,改善MAFLD。     

岩黄连总碱对代谢相关脂肪性肝病小鼠的治疗作用及分子机制研究

目的 研究岩黄连总碱对高糖高脂饮食诱导的代谢相关脂肪性肝病（MAFLD）小鼠的治疗作用。方法 随机取C57BL/6小鼠7只设置为对照组,喂以正常饲料;造模小鼠给予高脂饮食和高糖饮水（含20%果糖水）,连续喂养10周;将造模小鼠按体质量随机分为模型组、盐酸二甲双胍（阳性药,200 mg/kg）组和岩黄连总碱低、高剂量（25、100 mg/kg）组,继续饲以高脂高糖饮食,连续ig给药5周。记录小鼠体质量,取肝脏并拍照,测定小鼠肝脏质量,计算肝脏指数;应用血糖仪测定小鼠空腹血糖（FBG）及口服糖耐量（OGTT）;试剂盒法测定血清总胆固醇（TC）、三酰甘油（TG）、低密度脂蛋白胆固醇（LDL-C）、高密度脂蛋白胆固醇（HDL-C）及游离脂肪酸（NEFA）的水平;取肝组织进行HE染色、油红O染色和Masson染色;Western blotting检测肝组织中AMP依赖的蛋白激酶（AMPK）、p-AMPK、磷脂酰肌醇3-激酶（PI3K）、p-PI3K、蛋白激酶B （Akt）、p-Akt蛋白表达情况。结果 与对照组比较,模型组小鼠体质量、肝脏指数显著升高;给药后小鼠体质量及肝脏指数显著下降（P<0.05、0.01）。与模型组比较,岩黄连总碱显著降低小鼠的FBG及OGTT水平（P<0.01）;显著降低血清TC、TG、LDL-C及NEFA水平（P<0.01）;显著改善小鼠肝组织脂肪变及纤维化;显著上调MAFLD小鼠肝组织p-AMPK、p-PI3K、p-Akt蛋白水平（P<0.01）。结论 岩黄连总碱对MAFLD发挥显著治疗作用,其作用机制可能与通过激活AMPK/PI3K/Akt信号通路,减轻肝脏脂质沉积有关。     

金丝桃苷通过NOS/NO系统调控血管内皮影响动脉粥样硬化进程的实验研究

目的 探讨金丝桃苷通过一氧化氮合酶（NOS）/一氧化氮（NO）系统调控血管内皮影响动脉粥样硬化进程。方法 采用高脂饲料喂养ApoE^-/-小鼠复制动脉粥样硬化模型。在造模的同时给予金丝桃苷（200 mg/kg）和辛伐他汀（阳性对照,5.2 mg/kg）进行干预,每天给药2次,连续12周,每周称小鼠体质量;全血项分析仪检测小鼠血清中总胆固醇（TC）、三酰甘油（TG）、高密度脂蛋白胆固醇（HDL-C）和低密度脂蛋白胆固醇（LDL-C）的含量;ELISA法检测小鼠血清中丙二醛（MDA）、白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）、NO和内皮型一氧化氮合酶（eNOS）的含量;HE染色法和油红O染色法观察小鼠胸主动脉病理学变化情况和脂质沉积状况;Western blotting检测小鼠胸主动脉中聚二磷酸腺苷核糖聚合酶1（PARP1）、精氨酸酶Ⅱ（ARG2）、eNOS和诱导型一氧化氮合酶（iNOS）蛋白的表达。结果 与模型组比较,金丝桃苷显著抑制小鼠体质量增长（P<0.05、0.01）;显著降低小鼠血清中LDL-C、MDA和IL-6的水平（P<0.05、0.01）,显著升高NO和eNOS的水平（P<0.05、0.01）;显著减小小鼠主动脉管腔内斑块面积（P<0.05、0.01）并改善脂质沉积状况;显著下调小鼠主动脉组织PARP1、ARG2、iNOS的表达,并上调eNOS的表达（P<0.01）。结论 金丝桃苷可以减缓动脉粥样硬化的病理进程,可能是通过降低LDL-C水平、影响NOS活性、调节NO的合成,改善血管内皮功能实现的。     

熊去氧胆酸胶囊联合水飞蓟宾治疗酒精性肝硬化的临床疗效

目的 探讨熊去氧胆酸胶囊联合水飞蓟宾治疗酒精性肝硬化的临床疗效。方法 选取2016年1月-2018月1月在濮阳市人民医院收治的酒精性肝硬化患者100例,采用随机数字表法分为对照组和观察组,每组各50例,对照组患者仅给予水飞蓟宾,观察组患者给予熊去氧胆酸胶囊联合水飞蓟宾,比较两组患者治疗前后低密度脂蛋白胆固醇（LDL-C）、高密度脂蛋白胆固醇（HDL-C）、总胆固醇（TC）、三酰甘油（TG）、天冬氨酸氨基转移酶（AST）、丙氨酸氨基转移酶（ALT）和γ-谷氨酰转肽酶（GGT）、总胆红素（Tbil）、直接胆红素（Dbil）和间接胆红素（Ibil）的水平并比较治疗期间不良反应的发生率。结果 治疗后,两组患者的GGT、ALT及AST水平均显著降低,同组治疗前后比较差异有统计学意义（P<0.05）;与对照组相比,观察组患者的GGT、ALT及AST水平均显著降低,差异具有统计学意义（P<0.05）。治疗后,两组患者的Tbil、Dbil及Ibil水平均显著降低,差异具有统计学意义（P<0.05）;与对照组相比,观察组患者的Tbil、Dbil及Ibil水平均显著降低,差异具有统计学意义（P<0.05）。治疗后,观察组患者的LDL-C、TC及TG水平均显著降低,而HDL-C显著升高,同组治疗前后比较差异有统计学意义（P<0.05）;与对照组相比,观察组患者的LDL-C、TC及TG水平均显著降低,而HDL-C显著升高,差异具有统计学意义（P<0.05）。观察组患者的不良反应发生率（8.00%）显著低于对照组（24.00%）,差异具有统计学意义（P<0.05）。结论 熊去氧胆酸胶囊联合水飞蓟宾治疗酒精性肝硬化的临床效果较好,能够有效改善患者的血脂水平并提高肝功能。     

高糖高脂诱导大鼠代谢相关脂肪性肝病模型的建立

目的 建立SD大鼠代谢相关脂肪性肝病（metabolic associated fatty liver disease,MAFLD）模型,观察大鼠病理变化。方法 用高糖高脂饲料饲喂雄性SD大鼠20周,检测模型组大鼠血清和肝匀浆相关生化指标的水平、肝脏脏器质量和系数、肝脏组织病理学变化。结果 模型组大鼠饲喂高糖高脂饲料20周后,与对照组比较,血清总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）及肝脏TC和三酰甘油（TG）的水平均显著升高（P<0.01）,血清TG、高密度脂蛋白胆固醇（HDLC）的水平均显著降低（P<0.01）,肝脏质量及系数显著性增加（P<0.01）。肝组织的病理改变为严重肝细胞脂肪变性及多灶性肉芽肿性炎。结论 高糖高脂饲料饲喂成功建立了合适的MAFLD动物模型,肝脏病理改变可见广泛的脂肪变性和大量的肉芽肿性炎症,未见纤维化。     

水飞蓟宾对高脂诱导非酒精性脂肪肝大鼠的调脂保肝作用

目的 探讨水飞蓟宾对高脂诱导的非酒精性脂肪肝（NAFL）模型大鼠的调脂保肝作用。方法 采用ig高脂乳剂配合高脂饲料制备大鼠NAFL模型,持续4周,对照组给予生理盐水和普通饲料。模型大鼠随机分为模型组、辛伐他汀（阳性药,1.8 mg/kg）组和水飞蓟宾低、中、高剂量（18.9、37.8、75.6 mg/kg）组,第5周在继续造模的基础上ig给药,每天1次,持续8周。末次给药后,称取肝脏质量并计算肝系数;HE染色观察肝组织病理形态;腹主动脉取血,分离血清,试剂盒法检测三酰甘油（TG）、总胆固醇（TC）、高密度脂蛋白（HDL）、低密度脂蛋白（LDL）、天冬氨酸转氨酶（AST）、丙氨酸转氨酶（ALT）水平。结果 连续治疗8周后,与对照组比较,水飞蓟宾高、中剂量均可明显改善肝组织脂肪变性程度;各剂量组肝系数均显著下降（P<0.05、0.01）;各剂量组均显著降低血清TC、TG、AST、ALT水平（P<0.05、0.01）;高、中剂量组显著降低LDL、升高HDL水平（P<0.01）。结论 水飞蓟宾对NAFL大鼠发挥治疗作用,其作用可能与降脂、保肝有关。     

妊娠晚期血脂水平与不同类型子痫前期相关性分析

目的 分析妊娠晚期血脂水平与不同类型子痫前期的相关性。方法 回顾性分析院102例妊娠晚期子痫前期孕妇临床资料,其中51例轻度子痫前期（MPE）、31例晚发型重度子痫前期（LPE）、20例早发型重度子痫前期（EPE）,分别为MPE组、LPE组、EPE组,并选取同期102例无妊娠并发症的健康孕妇作为对照组。比较上述4组孕妇血清总胆固醇（TC）、三酰甘油（TG）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）水平差异,并使用ROC曲线评估血脂水平与不同类型子痫前期的相关性。结果 4组对象血清HDL-C水平比较,差异无统计学意义（P>0.05）;MPE组与对照组血清TC、TG、LDL-C水平比较,差异无统计学意义（P>0.05）;LPE组及EPE组血清TC、TG、LDL-C水平均高于MPE组和对照组（P<0.05）,且EPE组高于LPE组（P<0.05）。经ROC曲线分析,血清TC、TG、HDL-C、LDL-C对预测LPE的曲线下面积（AUC）分别为0.592、0.688、0.446、0.804,约登指数分别为0.189、0.343、0.129、0.563,其中以血清TG、LDL-C对预测LPE有意义（P<0.05）;而对预测EPE的AUC分别为0.891、0.973、0.357、0.894,约登指数分别为0.725、0.861、0.350、0.733,其中以TC、TG、LDL-C对预测LPE有意义（P<0.05）,且各血脂指标预测EPE的AUC及约登指数均高于上述预测LPE。结论 血脂代谢异常与妊娠晚期EPE及LPE的发生均有关,但对EPE的影响更大,能作为预测EPE发生的辅助手段。     

乌药叶提取物对高脂血症模型大鼠降脂作用以及肝脏LKB1-AMPK通路的影响

目的 考察乌药叶提取物对高脂血症大鼠模型降血脂作用以及对肝脏LKB1-AMPK通路相关蛋白表达的影响。方法 采用高脂饲料诱导的混合型高脂血症大鼠模型,以高、低剂量（1.6,0.8 g·kg^-1以生药量计）的乌药叶提取物灌胃,阳性药组给予非诺贝特20 mg·kg^-1,连续8周。分别在4,8周后检测血清中总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）及高密度脂蛋白胆固醇（HDL-C）水平。实验末处死大鼠,解剖取肝脏,计算肝脏指数,油红O染色观察肝组织脂质蓄积程度,Western blotting检测肝脏LKB1-AMPK通路相关蛋白的表达。结果 连续给药4周,与模型组相比,阳性药组血清TG水平有显著降低（P<0.05）。连续给药8周,与模型组相比,高剂量组能显著降低血清中TC、TG、LDL-C的水平（P<0.01或P<0.05）。与对照组比,高、低剂量组和模型组肝脏指数均极显著升高（P<0.01）;与模型组比,高、低剂量组有降低的趋势,但差异无统计学意义。肝组织油红O染色结果显示,模型组肝细胞脂质蓄积严重,脂肪变性程度高,高剂量组肝细胞脂质蓄积和脂肪变性程度均有不同程度的改善。高、低剂量组均可显著提高模型大鼠肝脏AMPKα蛋白磷酸化水平。结论 乌药叶提取物能够降低血清脂质水平,改善肝细胞脂质蓄积,并且增加AMPKα蛋白磷酸化水平,激活AMPKα,从而促进脂质代谢。     

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.

     

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.     

2-(Acetoxyphenyl)-(Z)-styryl sulfides as cyclooxygenase inhibitors

2-(Acetoxyphenyl)-(Z)-styryl sulfides are described as selective cyclooxygenase-2 (COX-2) inhibitors, useful for treating inflammation and COX-2-mediated disorders including neoplasia. 2-(Acetoxyphenyl)-(Z)-styryl sulfide is claimed to be the most potent COX inhibitor in the series with a COX-2 selectivity ratio of 33. This compound is also claimed to be superior to celecoxib (Celebrex^®, Pfizer) in inhibiting cell growth of colorectal carcinoma cells. In this evaluation, the COX inhibitory activity of this compound is compared to that previously disclosed for diarylheterocycles and 2-(acetoxyphenyl)alkyl sulfides. The validity of the DLD-1 cell line in the growth inhibition studies is questioned based on recent literature reports indicating the lack of COX-2 expression in this cell line.     

Sleep-disordered breathing with chronic opioid use

Chronic opioid use for pain relief or as substitution therapy for illicit drug abuse is prevalent in our societies. In the US, retail distribution of methadone and oxycodone has increased by 824 and 660%, respectively, between 1997 and 2003. μ-Opioids depress respiration and deaths related to illicit and non illicit chronic opioid use are not uncommon. Since 2001 there has been an emerging literature that suggests that chronic opioid use is related to central sleep apnoea of both periodic and non-periodic breathing types, and occurs in ～ 30% of these subjects. The clinical significance of these sleep-related abnormalities are unknown. This review addresses the present knowledge of control of ventilation mechanisms during wakefulness and sleep, the effects of opioids on ventilatory control mechanisms, the sleep-disordered breathing found with chronic opioid use and a discussion regarding the future research directions in this area.     

Drug targets for cognitive enhancement in neuropsychiatric disorders

The investigation of novel drug targets for treating cognitive impairments associated with neurological and psychiatric disorders remains a primary focus of study in central nervous system (CNS) research. Many promising new therapies are progressing through preclinical and clinical development, and offer the potential of improved treatment options for neurodegenerative diseases such as Alzheimer's disease (AD) as well as other disorders that have not been particularly well treated to date like the cognitive impairments associated with schizophrenia (CIAS). Among targets under investigation, cholinergic receptors have received much attention with several nicotinic agonists (α7 and α4β2) actively in clinical trials for the treatment of AD, CIAS and attention deficit hyperactivity disorder (ADHD). Both glutamatergic and serotonergic (5-HT) agonists and antagonists have profound effects on neurotransmission and improve cognitive function in preclinical experiments with animals; some of these compounds are now in proof-of-concept studies in humans. Several histamine H3 receptor antagonists are in clinical development not only for cognitive enhancement, but also for the treatment of narcolepsy and cognitive deficits due to sleep deprivation because of their expression in brain sleep centers. Compounds that dampen inhibitory tone (e.g., GABA_A α5 inverse agonists) or elevate excitatory tone (e.g., glycine transporter inhibitors) offer novel approaches for treating diseases such as schizophrenia, AD and Down syndrome. In addition to cell surface receptors, intracellular drug targets such as the phosphodiesterases (PDEs) are known to impact signaling pathways that affect long-term memory formation and working memory. Overall, there is a genuine need to treat cognitive deficits associated with many neuropsychiatric conditions as well as an increasingly aging population.