精蛋白重组人胰岛素注射液(预混50/50)与50/50混合重组人胰岛素注射液在Beagle犬体内的生物等效性研究

目的研究精蛋白重组人胰岛素注射液(预混50/50)与已上市的50/50混合重组人胰岛素注射液在Beagle犬体内的药动学和生物等效性。方法采用单剂量试验制剂和参比制剂自身双交叉给药方案,12只健康Beagle犬分别皮下注射同剂量精蛋白重组人胰岛素注射液(预混50/50)和50/50混合重组人胰岛素注射液,给药后不同时间经静脉采集血浆标本,同时采用罗氏血糖仪同步测定动物血糖水平;放射免疫分析(RIA)法检测血药浓度;血药浓度数据用DAS 2.0药动学软件拟合计算参数,并进行生物等效性分析。结果 Beagle犬交叉sc 5 U/只试验制剂与参比制剂后,主要药动学参数分别为:平均t1/2为(2.62±2.14)、(1.99±1.37)h;平均Cmax为(108.30±26.90)、(104.60±18.45)μU/m L;平均tmax为(0.94±0.43)、(0.90±0.39)h;平均AUC(0-t)为(362.3±73.6)、(351.7±53.9)μU/(m L·h)。血浆最低葡萄糖浓度(Cmin)分别为(1.74±0.25)、(1.80±0.33)mmol/L,达到最低浓度所需时间(tmin)分别为(1.58±0.97)、(2.02±0.96)h。结论精蛋白重组人胰岛素注射液(预混50/50)与50/50混合重组人胰岛素注射液在Beagle犬体内具有生物等效性。     

重组人胰岛素注射液临床前生物相似性评价研究

目的 通过Beagle犬长期给药毒性试验及免疫原性试验,评价重组人胰岛素注射液(Insulin R)与原研药(Humulin R)的生物相似性。方法 进行Beagle犬scInsulin R 30 d停药14 d长期给药毒性试验,Insulin R剂量为0.5、1.0、1.5 IU/kg,Humulin R剂量为1.5 IU/kg,检测指标包括一般状况、进食量、体温、心电图、血液学、凝血、血清生化、电解质及尿液等,于给药期结束及停药期结束分两次剖杀动物,测定主要脏器的脏器系数并进行常规病理组织学检查;ELISA法检测Beagle犬血清的免疫原性。结果 Beagle犬重复sc Insulin R 30 d毒性试验中,中、高剂量组部分动物出现食欲降低、食量减少,高剂量1只雄性动物出现流涎、站立不稳、心率加速、抽搐等低血糖症状,中、高剂量组动物心率增加;原研药组与InsulinR高剂量组毒性反应相当;Beagle犬给予Insulin R 30 d未检测到抗药抗体。结论 Beagle犬sc Insulin R 30 d时的最大无毒反应剂量为0.5 IU/kg,相当于临床等效剂量的0.5倍,且未产生抗药抗体,与Humulin R具有较好的临床前生物相似性。     

胰岛素胶囊在Beagle犬体内的药动学和药效学研究

目的研究胰岛素胶囊在Beagle犬体内药动学和药效学特征。方法 4只健康Beagle犬sc重组人胰岛素注射液以及po和内窥镜给予胰岛素胶囊,不同时间经静脉采集血浆标本,同步测定血糖水平,采用放射免疫分析法检测血药浓度。结果 4只Beagle犬自身交叉分别sc胰岛素注射液和po胰岛素胶囊或内窥镜给予内容物后,以血浆外源性胰岛素浓度计算得到的主要药动学参数,t_(1/2)分别为(0.986±0.185)、(0.649±0.508)、(0.518±0.187)h;C_(max)分别为(102.0±45.7)、(625.0±360.0)、(453.0±636.0)μU/mL;tmax分别为(0.375±0.224)、(0.750±0.289)、(0.500±0.601)h;AUC_(0-t)分别为(181.0±42.6)、(414.0±246.0)、(423.0±526.0)μU/(mL·h)。胰岛素胶囊po和内窥镜插管给药的相对生物利用度分别为(5.41±2.26)%、(8.31±9.94)%。po和内窥镜这两种途径的胰岛素胶囊在0.5~1.0 h浓度达到最大,然后在血液中的外源性胰岛素浓度逐渐降低,直至检测不到,波动范围较大;t_(1/2)基本为0.5 h左右,作用时间较短;血糖值降低的维持时间较短,回升速度快,且血糖值的波动较大。结论通过直接po和内窥镜给予胰岛素胶囊内容物,与sc短效胰岛素的结果相比,尽管口服胰岛素胶囊在Beagle犬体内吸收和消除均比较快,动物的个体差异影响较明显;但是仍然具有降糖的作用。     

头孢丙烯分散片在Beagle犬体内的药动学和相对生物利用度研究

目的建立高效液相色谱（HPLC）法测定犬血浆中头孢丙烯的质量浓度,研究头孢丙烯分散片在Beagle犬体内的药动学和相对生物利用度。方法 12只Beagle犬双周期随机交叉单剂量口服500mg头孢丙烯分散片和普通片剂,洗净期为1周,采用HPLC法测定血浆中头孢丙烯的质量浓度。结果分散片与普通片的体内过程基本一致,其主要药代动力学参数峰浓度（Cmax）分别为（48.7±4.2）μg/mL和（51.1±3.3）μg/mL,达峰时间（Tmax）分别为（1.5±0.3）h和（2.0±0.4）h,半衰期（t1/2）分别为（1.2±0.3）h和（1.6±0.4）h,0～24h药-时曲线下面积（AUC0-24）分别为（188.9±27.5）μg/（h·mL）和（208.2±34.3）μg/（h·mL）。结论头孢丙烯分散片口服后吸收迅速,平均相对生物利用度为90.7%。     

精蛋白重组人胰岛素注射液生物类似药非临床安全性评价

目的 通过小鼠单次给药毒性试验、Beagle犬重复毒性及免疫原性试验和豚鼠全身主动过敏试验,考察精蛋白重组人胰岛素注射液（Insulin NPH）的毒副反应、毒性靶器官或靶组织,为开展临床试验提供依据。方法 ①小鼠单次给药毒性试验：采用最大给药量法分别sc生理盐水、溶媒和Insulin NPH（2092~2488 IU/kg）,监测给药后小鼠一般状态、体质量、脏器异常。②Beagle犬重复毒性试验：sc溶媒、原研对照药（Humulin NPH,1.5 IU/kg）,低、中和高剂量（0.5、1.0和1.5IU/kg）的Insulin NPH,每天1次,连续30 d,停药恢复14 d;在给药期和恢复期内观察动物的一般体征和注射部位的局部刺激性,进行体质量、肛温、血糖及心电图检查,测定血液学、血清生化、尿液常规等指标,并进行脏器质量及组织病理学检查;免疫原性试验采用间接ELISA法检测不同给药期Beagle犬血清中抗药结合抗体。③豚鼠主动全身过敏试验：分别sc低和高剂量（4和12 IU/kg）的Insulin NPH、生理盐水和溶媒,另设卵清白蛋白为阳性对照,使用以上剂量进行5次致敏试验后,iv 3倍致敏剂量进行激发试验,观察豚鼠过敏症状。结果 小鼠sc 165倍临床常用剂量的Insulin NPH后,未见明显毒性反应;Beagle犬重复毒性试验中1.0 IU/kg是Insulin NPH的无毒反应剂量（NOAEL）,该剂量相当于临床拟用剂量的2倍,免疫原性试验各剂量组均未发现抗药结合抗体;豚鼠主动全身过敏试验中未见明显过敏症状。结论 在本试验条件下未观察到Insulin NPH明显毒性反应。     

替硝唑果胶骨架型结肠定位缓释片在犬体内药动学研究

目的 研究替硝唑果胶骨架型结肠定位缓释片在犬体内药动学.方法 采用双周期交叉试验设计,6只健康Beagle犬分别服用受试制剂或参比制剂,用HPLC法测定Beagle犬血浆中药物浓度.结果 受试、参比制剂在犬体内的血药浓度变化符合二室模型,其主要药动学参数：Tmax分别为（7.0±0.92）和（2.0±0.31）h;Cmax分别为（66.97±5.9）和（112.2±7.4）μg/L;AUC0-t分别为（1243.88±25.67）和（1523.84±27.89）mg·h/L;AUC0-∞分别为（1277.18±30.58）和（1548.67±20.89）mg·h/L,受试制剂的相对生物利用度为82.47%.结论 本法准确、灵敏,适用于替硝唑果胶骨架型结肠定位缓释片的药动学研究.     

硝苯地平缓释片临床前药动学及生物利用度研究

目的研究硝苯地平缓释片在Beagle犬体内的药动学和生物利用度。方法采用双周期随机交叉试验设计,分别给予8只Beagle犬受试制剂（硝苯地平缓释片）或参比制剂（硝苯地平控释片）30mg,采用LC-MS/MS法测定给药后不同时间的血药浓度。选用DAS2.0软件计算药动学参数,并对药代参数进行配对t检验统计分析。结果血浆中硝苯地平线性范围为0.05～30ng/mL,最低定量限为0.05ng/mL,分析方法灵敏、准确、特异性高。受试制剂和参比制剂的峰浓度、达峰时间和药-时曲线下面积分别为（4.46±2.11）、（5.21±2.68）ng/mL,（11.0±3.85）、（7.38±2.97）h,（49.5±25.9）、（49.6±25.2）ng·h/mL。以药–时曲线下面积计算受试制剂的相对生物利用度为（104±43.5）%。结论建立的分析方法操作简单、准确、重复性好,可用于犬体内硝苯地平药动学和相对生物利用度的研究;受试制剂具有一定的延迟释放特征。     

雷贝拉唑钠肠溶胶囊Beagle犬体内药动学及生物等效性研究

目的：建立HPLC-MS测定方法分析Beagle犬血浆中雷贝拉唑的含量,并作不同厂家两种雷贝拉唑钠肠溶胶囊的药动学及生物等效性研究。方法：6只Beagle犬随机分为两组,采用单剂量双周期交叉试验,分别口服给予60 mg雷贝拉唑钠肠溶胶囊受试制剂或参比制剂,给药后不同时间点采血,测定血药浓度,利用DAS3.0软件计算药动学参数,并比较两个厂家生产的制剂的生物等效性。结果：Beagle犬单次给予雷贝拉唑钠肠溶胶囊受试制剂和参比制剂后的tmax分别为（3.57±0.91）h和（3.43±0.87）h,Cmax分别为（539.03±129.13）ng·mL-1和（554.90±135.75）ng·mL-1,t1/2分别为（2.20±0.90）h和（2.09±0.78）h,药时曲线下面积AUC（0→24 h）分别为（1341.40±442.03）ng·h·mL-1和（1319.41±402.29）ng·h·mL-1。结论：结果表明不同厂家的两种雷贝拉唑钠肠溶胶囊具有生物等效性。     

琥珀酸去甲文拉法辛缓释片在Beagle犬体内的药动学和生物等效性

目的建立HPLC-MS/MS法测定Beagle犬血浆中去甲文拉法辛的质量浓度,研究Beagle犬经口给予琥珀酸去甲文拉法辛缓释片后的药动学特征和生物等效性。方法 24只Beagle犬双周期、自身交叉、单次/多次(连续给药7 d)经口给予琥珀酸去甲文拉法辛缓释片,采用HPLC-MS/MS法测定给药后不同时间点血浆中去甲文拉法辛的经时血药质量浓度,并计算药动学参数。结果单次经口给予受试与参比制剂后去甲文拉法辛的主要药动学参数分别为ρmax(28.1±5.7)和(26.9±7.7)μg·L-1;tmax(1.3±0.6)和(1.6±1.0)h;t1/2(3.4±1.0)和(3.3±1.0)h;AUC0→t(147.8±58.2)和(144.6±67.4)μg·h·L-1;AUC0-∞(159.8±59.2)和(159.1±67.1)μg·h·L-1;相对生物利用度为(106.2±19.7)%。多次经口给予受试与参比制剂7 d后的主要药动学参数分别为ρmax(34.0±14.4)和(33.2±16.7)μg·L-1;tmax(1.6±0.8)和(1.6±0.7)h;t1/2(3.2±1.1)和(3.5±1.3)h;AUC0→t(172.4±94.8)和(162.5±78.1)μg·h·L-1;AUC0-∞(178.8±98.8)和(168.8±77.1)μg·h·L-1;相对生物利用度为(107.2±39.2)%。结论单次和多次给药后,受试制剂的药动学参数ρmax和AUC对数转换后比值的90%置信区间均在参比制剂的生物等效性标准范围内,2种制剂在Beagle犬体内生物等效。     

国产与进口替莫唑胺胶囊在Beagle犬体内的生物等效性研究

目的:研究国产与进口替莫唑胺胶囊在Beagle犬体内的药动学及生物等效性。方法:6只Beagle犬随机交叉单剂量口服进口替莫唑胺胶囊(参比制剂)和国产替莫唑胺胶囊(受试制剂),采用HPLC法测定犬血浆中替莫唑胺的浓度,Bapp 3.0软件计算其主要药动学数据,并进行两种制剂的等效性评价。结果:参比制剂与受试制剂的Cmax分别为(11.35±1.35)和(11.70±2.77)μg·m L-1;Tmax分别为(0.97±0.56)和(1.08±0.49)h;t1/2β分别为(1.44±0.37)和(1.43±0.24)h;AUC0~t分别为(27.34±2.30)和(28.34±7.47)μg·h·m L-1,AUC0~∞分别为(29.85±4.49)和(30.85±8.46)μg·h·m L-1。受试制剂对参比制剂的相对生物利用度为(106.1±36.1)%。结论:本实验结果表明,两种替莫唑胺胶囊在Beagle犬体内具有生物等效性。     

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.