胍丁胺代谢产物腐胺对吗啡镇痛、耐受和依赖的影响

目的观察腐胺对吗啡镇痛、耐受及依赖的影响,探讨腐胺治疗阿片耐受性和依赖性的潜力。方法小鼠醋酸扭体模型和55℃热板法测痛阈;吗啡恒定剂量给药制备耐受模型,55℃热板法测痛阈;吗啡递增剂量给药制备依赖模型,纳洛酮催促观察戒断症状,以胍丁胺(40 mg.kg-1,ig)为阳性对照药,腐胺灌胃给药剂量分别为10,20,40,80 mg.kg-1。结果在小鼠醋酸扭体模型中腐胺具有镇痛作用;而在小鼠55℃热板实验中,腐胺本身无镇痛作用,能较弱地增强吗啡镇痛;腐胺能够减弱吗啡耐受的形成,对已形成的吗啡耐受也有治疗作用;腐胺能够减弱吗啡躯体依赖的形成和表达。结论腐胺和胍丁胺具有相似的生物学活性,具有治疗阿片耐受和依赖的潜力。     

利鲁唑对吗啡镇痛、耐受和依赖作用的影响(英文)

目的　研究利鲁唑对阿片镇痛、耐受及躯体功能的调节。方法　采用冰醋酸扭体 ,5 5℃热板法和热辐射甩尾法观察利鲁唑对小鼠痛阈及吗啡镇痛效应的影响 ;采用小鼠急性和慢性吗啡耐受模型及小鼠吗啡依赖模型 ,观察利鲁唑对吗啡耐受和依赖的作用。结果　单独皮下注射利鲁唑 2 .5～ 10mg·kg- 1在以上 3种模型无镇痛作用 ,然而能剂量依赖性地增强吗啡镇痛效应。利鲁唑 2 .5～ 10mg·kg- 1剂量依赖性地对抗吗啡引起的急性和慢性耐受。在小鼠吗啡依赖模型中 ,利鲁唑 2 .5～ 10mg·kg- 1剂量依赖性地抑制吗啡戒断症状的产生。结论　利鲁唑自身无镇痛作用 ,但能显著增强吗啡镇痛效应 ,并能预防吗啡所引起的耐受和依赖     

咪唑克生对吗啡镇痛、耐受和身体依赖的影响

目的:观察咪唑克生对吗啡镇痛及吗啡所致耐受和躯体依赖的影响.方法:采用小鼠醋酸扭体实验和55℃热板实验观察咪唑克生对基础痛阈及吗啡镇痛作用的影响;采用小鼠热辐射甩尾实验和小鼠55℃热板实验观察咪唑克生对吗啡耐受形成过程的影响;采用大鼠、小鼠身体依赖模型观察咪唑克生对吗啡所致身体依赖的影响.结果:咪唑克生(3-9mg/kg)能显著降低小鼠基础痛阈,抑制吗啡镇痛;加重吗啡所致耐受;诱发大、小鼠发生戒断综合征.结论:咪唑啉受体参与痛阈形成;咪唑克生能抑制吗啡镇痛,加重吗啡所致耐受;并诱发吗啡依赖性动物发生戒断综合征.     

济泰片对小鼠诱发性疼痛及对吗啡躯体依赖小鼠戒断症状的影响

目的:观察济泰片对诱发的小鼠疼痛的镇痛作用和对吗啡依赖小鼠催促戒断症状的影响。方法:(1)采用小鼠醋酸扭体法,观察经胃给予2.4 g.kg-1,3.6 g.kg-1,4.8 g.kg-1三种浓度济泰片的镇痛作用;(2)采用小鼠热板法,观察经胃给予6.0 g.kg-1,9.0 g.kg-1,12.0 g.kg-1三种浓度济泰片的镇痛作用;(3)采用连续递增给药法建立吗啡依赖小鼠模型,观察经胃给予1.2 g.kg-1,2.4 g.kg-1,3.6 g.kg-1济泰片后对吗啡依赖小鼠的纳洛酮催促戒断跳跃反应的影响。结果:(1)济泰片溶液呈剂量依赖性的抑制醋酸诱发的小鼠扭体次数(P<0.01),对扭体次数的抑制率最高可达71.7%;(2)济泰片溶液能明显提高热板法诱发的小鼠疼痛痛阈值,其镇痛的ED50=8.34 g.kg-1;(3)伴随给予济泰片溶液能剂量依赖性地抑制纳洛酮催促所引起的吗啡躯体依赖戒断症状,使吗啡依赖小鼠跳跃次数明显减少(P<0.01)。结论:济泰片对诱发的小鼠疼痛有明显的镇痛作用,并能抑制吗啡躯体依赖小鼠的戒断症状。     

河豚毒素与吗啡联合用药对吗啡依赖性与镇痛耐受作用的影响

目的:研究河豚毒素(tetrodotoxin,TTX)与吗啡联合使用对吗啡依赖性及镇痛耐受作用的影响。方法:采用吗啡依赖性小鼠模型及热板实验,评价单独使用吗啡(2.5 ml.kg-1)以及联合给药(吗啡2.5 mg.kg-1+TTX 0.5μg.kg-1、吗啡2.5 mg.kg-1+TTX 1.0μg.kg-1)对纳洛酮催促戒断症状及镇痛耐受性的影响。结果:联合用药可以抑制吗啡依赖性小鼠戒断后体重的丢失,明显抑制吗啡依赖小鼠纳洛酮催促后的跳跃反应,抑制小鼠热板实验的潜伏期时间的增加。结论:TTX与吗啡联合用药可以抑制吗啡的依赖性与镇痛耐受作用的产生。     

三氟拉嗪对吗啡镇痛耐受性的翻转作用

目的··:研究三氟拉嗪对吗啡镇痛耐受性的影响。方法··:热板测痛法,测定三氟拉嗪对小鼠热板(55℃)痛阈值(s)的影响;慢性吗啡处理使小鼠对吗啡的镇痛作用产生耐受性 ,观察低剂量三氟拉嗪对吗啡耐受小鼠最大镇痛效率的影响。结果··:(1)三氟拉嗪(2-20mg·kg-1)呈剂量依赖性延长小鼠的热板(55℃)痛阈值(s) ;(2)慢性吗啡处理使6mg·kg-1 吗啡最大镇痛效率降低42.2%(P<0.05),9mg·kg-1 吗啡最大镇痛效率降低9.8%(P>0.05) ;(3)合用低剂量三氟拉嗪(2mg·kg-1)和吗啡(6mg.kg-1)可以使吗啡耐受小鼠的最大镇痛效率提高47.9 %(P<0.01),其最大镇痛效率与单独急性吗啡(6mg·kg-1)处理相同。结论··:三氟拉嗪对小鼠的吗啡镇痛耐受性存在翻转作用     

精氨酸及精氨酸脱羧酶抗体对痛阈及吗啡镇痛作用的影响(英文)

目的进一步阐明胍丁胺对阿片药理作用的影响。方法采用小鼠醋酸扭体法、小鼠热辐射甩尾法、小鼠热板法评价了精氨酸及精氨酸脱羧酶抗体对痛阈、吗啡镇痛及其耐受作用的影响。结果在小鼠醋酸扭体实验中,脑室注射精氨酸能剂量依赖性地抑制小鼠扭体次数,最大抑制率达84 %。在小鼠热辐射甩尾模型中,精氨酸不影响小鼠的甩尾时间,但能剂量依赖性地增强吗啡的镇痛作用,使吗啡2 .5 mg·kg-1的最大可能镇痛百分率从23 %增加到71 %。此外,在小鼠热辐射甩尾实验中,精氨酸能抑制吗啡100 mg·kg-1所诱导的急性耐受。精氨酸上述作用可被咪唑啉受体拮抗剂咪唑克生(3mg·kg-1,ip)所抑制。在小鼠热辐射甩尾实验和小鼠55℃热板实验中,精氨酸脱羧酶抗体能抑制吗啡镇痛,并能加重吗啡所致的耐受。结论上述结果提示,精氨酸及精氨酸脱羧酶在痛阈、吗啡镇痛及吗啡依赖形成过程中具有重要作用。     

左旋精氨酸及左旋精氨酸脱羧酶抗血清对吗啡镇痛及耐受的影响

目的:分析左旋精氨酸及左旋精氨酸脱羧酶(L-ADC)对吗啡镇痛及其所致耐受的影响。方法:用家兔制备L-ADC多克隆抗体;以小鼠热辐射甩尾法和小鼠55℃热板测痛模型分析此抗体及左旋精氨酸对吗啡镇痛和耐受的影响。结果:在热辐射甩尾和热板测痛模型中,0.5-50mg·kg~(-1)的左旋精氨酸(sc)不影响吗啡镇痛和耐受(P>0.05)。L-ADC抗血清(脑室注射,1:1000-1:10稀释)能对抗吗啡镇痛作用,在热辐射甩尾和热板测痛模型中,它能使吗啡可能最大镇痛百分率分别从94.3％和80.6％下降到57.7％和42.9％(P<0.01)。吗啡连续处理小鼠3d后形成耐受:在热辐射甩尾和热板测痛模型中,吗啡的可能最大镇痛百分率分别从90.3％和80.3％下降到47.2％和40.5％;L-ADC抗血清能进一步加重吗啡所致耐受,其可能最大镇痛百分率进一步下降至19.8％和27.7％(P<0.01)。结论:L-ADC可能参与调节了吗啡镇痛及耐受形成过程;而左旋精氨酸不影响吗啡镇痛和耐受。     

β-内酰胺类抗生素对吗啡耐受及依赖作用

为了研究头孢曲松及其类似物是否具有对抗吗啡耐受及依赖作用和头孢曲松对抗吗啡耐受的量效关系,本文采用小鼠热板舔足模型及纳洛酮戒断模型对头孢曲松、头孢拉定和头孢替安等6种β-内酰胺类抗生素进行观察,并与生理盐水对照组比较。100 mg.mL-1头孢曲松和头孢噻肟在吗啡形成耐受模型后第10天可能最大镇痛百分率(PMAP)分别为74.95%和65.94%,与生理盐水组(22.99%)比较具有显著性。100和50 mg.kg-1头孢曲松对戒断实验小鼠30 m in内平均跳跃次数为3.8和3.6,与对照组(20.9)比较具有显著性。结果表明,100 mg.kg-1头孢曲松和头孢噻肟对吗啡诱导的耐受和躯体依赖具有显著的抑制作用。头孢曲松具有剂量依赖性的抗吗啡耐受作用。     

河豚毒素与吗啡联合用药对吗啡依赖性与镇痛耐受作用的影响

目的:研究河豚毒素(tetrodotoxin,TTX)与吗啡联合使用对吗啡依赖性及镇痛耐受作用的影响。方法:采用吗啡依赖性小鼠模型及热板实验,评价单独使用吗啡(2.5 ml.kg-1)以及联合给药(吗啡2.5 mg·kg-1+TTX 0.5μg·kg-1、吗啡2.5 mg·kg-1+TTX 1.0μg·kg-1)对纳洛酮催促戒断症状及镇痛耐受性的影响。结果:联合用药可以抑制吗啡依赖性小鼠戒断后体重的丢失,明显抑制吗啡依赖小鼠纳洛酮催促后的跳跃反应,抑制小鼠热板实验的潜伏期时间的增加。结论:TTX与吗啡联合用药可以抑制吗啡的依赖性与镇痛耐受作用的产生。     

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.     

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.     

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.