高效液相色谱法测定川芎内酯软胶囊中4种苯酞成分

目的建立高效液相色谱法同时测定川芎内酯软胶囊中苯酞类化学成分洋川芎内酯-Ⅰ、洋川芎内酯-H、瑟丹酸内酯、藁本内酯的含量。方法 Shiseido Capcell Pak C18 MGⅡ色谱柱(4.6 mm×150 mm,5μm),流动相:甲醇-0.5%冰醋酸溶液,梯度洗脱,流速:0.7 m L·min-1,柱温:30℃,检测波长为280 nm,进样量:10μL。结果 4个化合物与周围干扰峰达到基线分离,线性范围分别为洋川芎内酯-Ⅰ0.193 3⁴.832μg·m L-1(r=0.993 8);洋川芎内酯-H 0.080 644.832μg·m L-1(r=0.993 8);洋川芎内酯-H 0.080 64².016μg·m L-1(r=0.999 8);瑟丹酸内酯3.4152.016μg·m L-1(r=0.999 8);瑟丹酸内酯3.415⁸5.38μg·m L-1(r=0.999 8);藁本内酯11.7985.38μg·m L-1(r=0.999 8);藁本内酯11.79²94.7μg·m L-1(r=0.999 2)。RSD均<2%(n=6),平均加样回收率在95%294.7μg·m L-1(r=0.999 2)。RSD均<2%(n=6),平均加样回收率在95%¹02%(n=6)。川芎内酯软胶囊中洋川芎内酯-Ⅰ、洋川芎内酯-H、瑟丹酸内酯、藁本内酯的含量分别为0.335 0、0.112 0、6.208、16.84 mg·g-1(n=3)。结论该法简便、快捷、结果准确、重复性好、实用性强,可用于川芎内酯软胶囊的质量控制。     

HPLC法测定心无忧片中洋川芎内酯H、洋川芎内酯I、洋川芎内酯A、藁本内酯、丹参素、丹酚酸B和丹参酮ⅡA

目的建立高效液相色谱梯度洗脱法同时测定心无忧片中洋川芎内酯H、洋川芎内酯I、洋川芎内酯A、藁本内酯、丹参素、丹酚酸B和丹参酮Ⅱ_A的方法。方法采用Hydrosphere C18色谱柱(250 mm×4.6 mm,5μm);流动相A:甲醇–乙腈(2∶1),流动相B:0.2%冰醋酸溶液,梯度洗脱(0~11 min,45.0%A;11~26 min,45.0%→68.0%A;26~39 min,68.0%→82.0%A;39~45 min,82.0%→45.0%A);检测波长:280 nm;体积流量:0.9 m L/min;柱温:30℃;进样量为10μL。结果洋川芎内酯H、洋川芎内酯I、洋川芎内酯A、藁本内酯、丹参素、丹酚酸B和丹参酮Ⅱ_A的线性范围分别为2.08~41.60μg/m L(r=0.999 3),3.36~67.20μg/m L(r=0.999 8),4.29~85.80μg/m L(r=0.999 9),6.26~125.20μg/m L(r=0.999 6),3.49~69.80μg/m L(r=0.999 2),49.08~981.60μg/m L(r=0.999 7),7.17~143.40μg/m L(r=0.999 5);平均加样回收率分别为96.81%、98.19%、99.24%、98.93%、97.39%、100.19%、98.63%,RSD值分别为1.51%、1.24%、0.98%、1.12%、0.84%、0.74%、1.44%。结论建立的HPLC梯度洗脱法同时测定心无忧片中心无忧片中洋川芎内酯H、洋川芎内酯I、洋川芎内酯A、藁本内酯、丹参素、丹酚酸B和丹参酮Ⅱ_A 7个成分的测定方法,供试品溶液处理简便,溶液稳定性好,检测方法快捷、准确、灵敏度高,为心无忧片质量标准的提高提供了参考。     

HPLC法测定不同贮藏条件下川芎中10种化学成分的含量

目的:建立同时测定不同贮藏条件下川芎中绿原酸、川芎嗪、阿魏酸、洋川芎内酯I、洋川芎内酯H、阿魏酸松柏酯、洋川芎内酯A、正丁基苯酞、Z-藁本内酯、丁烯基苯酞含量的方法。方法:采用高效液相色谱法。色谱柱为Boston C_(18),流动相为乙腈-0.5%醋酸溶液(梯度洗脱),流速为1.0 m L/min,检测波长为285 nm,柱温为30℃,进样量为5μL。结果:绿原酸、川芎嗪、阿魏酸、洋川芎内酯I、洋川芎内酯H、阿魏酸松柏酯、洋川芎内酯A、正丁基苯酞、Z-藁本内酯、丁烯基苯酞检测进样量线性范围分别为0.030 53～0.519 01μg(r=0.999 5)、0.001 02～0.017 34μg(r=0.999 9)、0.012 83～0.218 11μg(r=0.999 5)、0.007 63～0.129 71μg(r=0.999 7)、0.001 76～0.029 92μg(r=0.999 5)、0.054 74～0.930 58μg(r=0.999 9)、0.215 80～3.668 60μg(r=0.999 9)、0.018 02～0.306 34μg(r=0.999 7)、0.232 50～3.952 50μg(r=0.999 9)、0.002 40～0.040 80μg(r=0.999 5);定量限分别为2.073 7、0.556 6、0.753 8、0.231 5、0.306 9、0.925 2、2.295 3、4.624 0、3.215 3、0.910 5 ng,检测限分别为0.622 1、0.167 0、0.226 1、0.069 4、0.092 1、0.277 6、0.688 6、1.387 2、0.964 6、0.273 1 ng;精密度、稳定性、重复性试验的RSD均小于5%(n=6);加样回收率分别为95.90%～103.28%(RSD=2.99%,n=6)、88.24%～107.84%(RSD=4.89%,n=6)、95.06%～102.08%(RSD=3.97%,n=6)、93.67%～101.05%(RSD=1.02%,n=6)、94.81%～104.33%(RSD=2.34%,n=6)、94.41%～105.59%(RSD=4.32%,n=6)、92.76%～104.83%(RSD=1.95%,n=6)、87.22%～102.56%(RSD=2.89%,n=6)、94.04%～99.52%(RSD=0.92%,n=6)、88.51%～103.83%(RSD=4.89%,n=6)。5、15℃贮藏条件下,药材药品未见明显变质;室温条件下,部分样品出现虫蛀、霉变;6批药材样品各成分含量分别为0.047 7%～0.160 8%、0.006 1%～0.022 7%、0.048 2%～0.172 2%、0.023 3%～0.145 2%、0.004 6%～0.030 7%、0.085 2%～0.835 4%、0.182 6%～2.112 7%、0.009 9%～0.098 3%、0.614 9%～3.176 2%、0.005 7～0.036 9%,均呈下降趋势,且下降速率为5℃<15℃<室温;在相同贮藏温度下的下降速率为聚乙烯塑料袋<聚丙烯编织袋。结论:该方法准确、可行,可用于同时测定川芎中10种成分的含量。建议川芎药材密封包装后于干燥、阴凉处贮藏,且贮藏时间不宜过长。     

HPLC-CAD法测定川芎茶调散中绿原酸、阿魏酸、阿魏酸松柏酯、洋川芎内酯A、Z-藁本内酯、欧前胡素和异欧前胡素

目的建立高效液相色谱-电喷雾检测器(HPLC-CAD)法同时测定川芎茶调散中绿原酸、阿魏酸、阿魏酸松柏酯、洋川芎内酯A、Z-藁本内酯、欧前胡素、异欧前胡素。方法采用资生堂Capcell Pak MGⅡC18色谱柱(250 mm×4.6 mm,5μm);流动相:80%甲醇-10 mmol/L甲酸铵,梯度洗脱;体积流量:1.0 m L/min;柱温:40℃;CAD雾化器温度:35℃,采集频率:10 Hz,过滤常数:5.0;进样体积:20μL;稀释剂:70%甲醇。结果绿原酸、阿魏酸、阿魏酸松柏酯、洋川芎内酯A、Z-藁本内酯、欧前胡素、异欧前胡素的质量浓度分别在0.51～10.20μg/m L(r=0.999 4),0.53～10.60μg/m L(r=0.999 3),2.52～50.40μg/m L(r=0.999 5),5.05～101.00μg/m L(r=0.999 4),5.01～100.20μg/m L(r=0.999 8),1.02～20.40μg/m L(r=0.9995)、0.62～12.40μg/m L(r=0.9993)线性关系良好;平均回收率分别为99.46%、98.65%、98.48%、98.74%、98.60%、98.69%、98.58%,RSD值分别为1.62%、0.87%、1.03%、1.20%、1.25%、0.69%、0.66%。结论方法准确、重复性好,为川芎茶调散的质量研究提供了更加全面的方法。     

HPLC同时测定杜仲-川芎药对中的7种成分

目的 采用HPLC法同时测定杜仲-川芎药对中绿原酸、松脂醇二葡萄糖苷、阿魏酸、洋川芎内酯I、洋川芎内酯H、洋川芎内酯A、藁本内酯等7种成分的含量。方法 采用Agilent Eclipse XDB-C₁₈色谱柱(250 mm×4.6 mm, 5μm),流动相为乙腈-0.1%磷酸水,检测波长326 nm(绿原酸、阿魏酸、藁本内酯)、276 nm(松脂醇二葡萄糖苷、洋川芎内酯I、洋川芎内酯H、洋川芎内酯A),进样量10μL。结果 绿原酸、松脂醇二葡萄糖苷、阿魏酸、洋川芎内酯I、洋川芎内酯H、洋川芎内酯A、藁本内酯的线性范围分别为5.160～258.0、6.624～331.2、3.490～174.5、1.522～76.10、0.3212～16.06、25.44～1.277×10³、21.98～1.099×10³μg·mL^-1(r>0.999);平均加样回收率为96.73%～103.09%,RSD为0.68%～2.6%(n=6)。结论 所用方法高效、便捷、准确、稳定,可为杜仲-川芎药对的质量控制提供参考...     

HPLC梯度洗脱法同时测定前列舒通胶囊中9种成分的含量

摘要：目的:建立HPLC梯度洗脱法同时测定前列舒通胶囊中没食子酸、芍药内酯苷、芍药苷、阿魏酸、1,2,3,4,6-O-五没食子酰葡萄糖、洋川芎内酯Ⅰ、洋川芎内酯A、丹皮酚、藁本内酯9个成分的含量。方法:采用Caprisil C18-AQ色谱柱（250 mm×4.6 mm,5μm）,流动相为乙腈（A）-0.1%磷酸溶液（B）,梯度洗脱;检测波长为210 nm、230 nm、275 nm、280 nm、325 nm和350nm,流速1.0 ml·min-1,柱温35℃,进样量10μl,并使用Simca-P软件中的主成分分析（PCA）对含量结果进行分析。结果:没食子酸、芍药内酯苷、芍药苷、阿魏酸、1,2,3,4,6-O-五没食子酰葡萄糖、洋川芎内酯Ⅰ、洋川芎内酯A、丹皮酚、藁本内酯质量浓度分别在0.414～8.274μg·ml-1（r=0.998 5）、0.993～19.854μg·ml-1（r=0.998 0）、1.701～34.024μg·ml-1（r=0.999 7）、0.452～9.034μg·ml-1（r=0.999 9）、0.066～1.313μg·ml-1（r=0.998 5）、0.089～1.784μg·ml-1（r=0.998 1）、0.660～13.200μg·ml-1（r=0.998 0）、0.020～0.400μg·ml-1（r=0.999 0）、0.064～1.280μg·ml-1（r=0.999 5）范围内与峰面积呈良好线性关系;平均加样回收率分别为99.2%,99.4%,99.1%,99.7%,97.2%,97.6%,97.5%,99.3%和97.2%,其RSD分别为0.5%,0.3%,1.0%,0.4%,0.7%,1.0%,0.8%,0.3%和1.1%（n=6）。经PCA分析,没食子酸、芍药内酯苷、1,2,3,4,6-O-五没食子酰葡萄糖、洋川芎内酯A、丹皮酚5种成分是引起各批次之间差异的主要因素。结论:该方法准确、简单、可行,可用于同时测定前列舒通胶囊中上述9种活性成分的含量。     

GC测定颈复康颗粒中Z-藁本内酯和洋川芎内酯A的含量

目的建立颈复康颗粒中Z-藁本内酯和洋川芎内酯A的GC含量测定法。方法采用三氯甲烷一水溶剂萃取法提取川芎内酯类成分,采用气相色谱法,HP．5石英毛细管柱（30m×0．32mm×0．25μm）,FID检测器,程序升温系统进行检测。结果藁本内酯和洋川芎内酯A的线性范围分别是4．095～65．51μg．mL^-1（r=0．9999）,2．249～44．98gg．mL^-1（r=0．9998）。回收率分别为96．7％,97．2％。结论该方法简便快速,样品使用量少,可用于颈复康颗粒中Z-藁本内酯和洋川芎内酯A的含量测定。     

HPLC法同时测定大鼠血浆中川芎成分洋川芎内酯Ⅰ、藁本内酯和阿魏酸

目的建立以HPLC法同时测定大鼠血浆中洋川芎内酯Ⅰ、藁本内酯和阿魏酸质量浓度的方法。方法含药血浆进行3种提取方法对比。色谱条件为:Agilent 5TC-C18(2)(250mm×4.6mm,5μm);柱温为室温(25℃);流动相为甲醇-2mL·L~(-1)甲酸水梯度洗脱;流速为0.6mL·min~(-1);检测波长为280nm。结果以乙酸乙酯和正己烷为萃取溶剂的血样处理方法效果最佳;洋川芎内酯Ⅰ、藁本内酯和阿魏酸质量浓度分别在2.5~250,2.0~200和1.25~125μg·mL~(-1)范围内线性良好。平均回收率均大于85%,日内和日间RSD值均小于4%。结论该方法的血浆萃取效果较理想,检测方法简便、快速、灵敏、可靠,可应用于血浆中川芎主要成分的血药质量浓度分析。     

HPLC波长切换法同时测定强肝颗粒中8种活性成分的含量

摘要：目的:建立HPLC波长切换法同时测定强肝颗粒中（R,S）-告依春、绿原酸、芍药苷、阿魏酸、洋川芎内酯Ⅰ、藁本内酯、丹酚酸B、丹参酮ⅡA8个成分的含量。方法:采用Phenomenex Kinetex C18色谱柱（250 mm×4.6 mm,5μm）,流动相为乙腈（A）-0.05%磷酸溶液（B）,梯度洗脱,检测波长为245 nm[0～18 min检测（R,S）-告伊春]、320 nm（18～24 min检测绿原酸）、230 nm（24～28 min检测芍药苷）、286 nm（28～70 min检测阿魏酸、洋川芎内酯Ⅰ、藁本内酯、丹酚酸B和丹参酮ⅡA）,流速1.0ml·min-1,柱温35℃,进样量10μl。结果:（R,S）-告依春、绿原酸、芍药苷、阿魏酸、洋川芎内酯Ⅰ、藁本内酯、丹酚酸B、丹参酮ⅡA质量浓度分别在9.04～180.80μg·ml-1（r=0.998 3）、20.40～408.00μg·ml-1（r=0.999 8）、13.06～261.20μg·ml-1（r=0.999 7）、10.90～218.00μg·ml-1（r=0.999 9）、7.68～153.60μg·ml-1（r=0.999 2）、11.24～224.80μg·ml-1（r=0.998 6）、4.02～80.40μg·ml-1（r=0.998 8）、7.60～152.00μg·ml-1（r=0.999 0）范围内与峰面积呈良好线性关系;平均加样回收率分别为97.6%,98.2%,99.1%,98.7%,96.4%,96.2%,97.3%,97.0%,其RSD分别为1.4%,1.0%,0.7%,1.0%,1.0%,1.5%,1.1%,1.9%。结论:该方法准确、简单、有效,可用于同时测定强肝颗粒中上述8种活性成分的含量。     

HPLC-波长切换法同时测定消栓肠溶胶囊中7个成分的含量

目的:建立同时测定消栓肠溶胶囊中7个活性成分绿原酸、苦杏仁苷、芍药苷、阿魏酸、洋川芎内酯Ⅰ、毛蕊异黄酮苷和藁本内酯的含量。方法:采用高效液相色谱法,色谱柱为Agilent Eclipse Plus C18,流动相为乙腈-0.1%磷酸溶液,梯度洗脱,检测波长为326 nm(绿原酸)、210 nm(苦杏仁苷)、230 nm(芍药苷)、321 nm(阿魏酸)、334(洋川芎内酯Ⅰ)、274 nm(毛蕊异黄酮苷)、260 nm(藁本内酯),流速为1.0 mL/min,柱温为35℃,进样量为10μL。结果:绿原酸、苦杏仁苷、芍药苷、阿魏酸、洋川芎内酯Ⅰ、毛蕊异黄酮苷和藁本内酯检测质量浓度的线性范围分别为1.16～34.81、1.85～55.48、13.22～396.50、13.50～405.09、1.75～52.51、2.74～82.18、7.67～230.07μg/mL(r为0.999 1～0.999 7);定量限分别为0.056、0.103、0.085、0.013、0.136、0.184、0.276μg;精密度、稳定性(24 h)、重复性试验的RSD<2.0%(n=6);平均回收率分别为99.3%、98.6%、98.8%、99.7%、97.1%、97.6%和99.2%(RSD<2.0%,n=6)。结论:建立的含量测定方法操作简便、结果准确,可用于消栓肠溶胶囊中7个成分的同时测定。     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.

     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.     

Gender-related symptoms and correlates of alcohol dependence among men and women with a lifetime diagnosis of alcohol use disorders

This study explored gender-related symptoms and correlates of alcohol dependence in a crosssectional study of 150 men and 150 women with a lifetime diagnosis of alcohol use disorders (AUD). Participants were recruited in equal numbers from treatment settings, correctional centres and the general community. Standardized measures were used to determine participants' use of substances, history of psychiatric disorders and psychosocial stress, their sensation seeking and family history of substance use and mental health disorders. Multivariate analyses were used to detect patterns of variables associated with gender and the lifetime severity of AUD. Men had a longer history of severe AUD than women. Women had similar levels of alcohol dependence and medical and psychological sequelae as men, despite 6 fewer years of AUD. More women than men had a history of severe psychosocial stress, severe dependence on other substances and antecedent mental health problems, especially mood and anxiety disorders. There were differences in family history of alcohol-related problems approximating same-gender aggregation. The severity of a lifetime AUD was predicted by its earlier age at onset and the occurrence of other disorders, especially anxiety, among both men and women. The limitations in the generalizability of these findings due to sample idiosyncrasies are discussed.     

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.