自然冻融蟾蜍眼球的形态学观察

本实验采用自然和离体冻融(—22),冷冻蟾蜍眼球。将其分为在体和离体冻融。冷冻60分钟后,用0.2%甘油30℃复温,1—2分钟后复苏,速将其眼球经组织学常规处理。HE染色,olympus显微镜观察及图像分析冻融后蟾蜍眼球组织结构的变化。离体眼球组,显微镜下可见:角膜、视网膜、脉络膜、巩膜细胞体积增大,颗粒增多现象。纤维呈透明玻璃样变。在体冷冻复温组,眼球组织结构完整。各种细胞和纤维清楚可见,实验结果提示:蟾蜍眼球可以左—22℃条件下至少保存60分钟。0.1%甘油30℃复温。1—2分钟复苏。实验结果提示:眼球器官具有活力和功能。     

蟾蜍肌组织自然冻融的组织学观察

本实验观察了冬眠状态下,蟾蜍在体和离体的心脏和骨骼肌冻融后形态学变化。Olympus显微镜观察和图像分析:在体冻融蟾蜍心肌和骨骼肌,组织结构完整。肌纤维,肌细胞,毛细血管均清楚可见。结果表明:蟾蜍心脏及骨骼肌可在自然温度—22℃暴露冷冻50分钟。以500ml温术为30℃复温,1—2分钟,使其心脏和骨骼肌组织恢复活力和功能。     

自然冻融蟾蜍脑组织的形态学观察

本实验用自然温度(-22℃)冷冻蟾蜍脑组织。将蟾蜍分为在体脑和离体脑组织冻融。分别自然暴露冷冻60分钟。以0.1％甘油30℃将蟾蜍复温,1～2分钟蟾蜍复苏。与此同时,经组织学常规处理,HE染色,光镜观察。结果在体冷冻复温组:脑组织结构完整,分辨清楚,可见星形胶质细胞和少突胶质细胞。离体冷冻脑组:脑组织细胞各层次分辨不清,这种现象是冷冻时冰晶形成所致。实验结果提示:蟾蜍脑组织可在-22℃条件下至少保存60分钟,其脑组织具有活力和功能。这对组织、细胞、器官的低温保存和移植具有重要价值。     

人参合剂对冻融蟾蜍心脏电生理理化特性的影响

目的:观察人参合剂对冻融蟾蜍心脏和血液电生理物理化学的影响.探索:人参合剂对心血管保护作用及物理化学特性.方法:采用冰箱-22℃冷冻蟾蜍冷休克模型,并将其分为正常对照组、RS任氏液组,人参药物合剂组80～83℃复温,采用计算机生物机能实验系统,记录观察不同温度蟾蜍复活心电图变化.结果:人参合剂组心电图波形PQRST明显比RS任氏液和对照组好.结论:人参合剂复温对冻融蟾蜍心血管具有保护作用.     

茯苓合剂对冻融蟾蜍血液理化特性的影响

目的:本实验旨在探讨血液、细胞、亚细胞和分子、离子通道等不同水平的冻融损伤和低温保护物理化学机制。方法:本实验采用Spectrumlab22PC分光光度计分别观察-22℃~37℃复温情况下冻融蟾蜍血液氧自由基与茯苓合剂保护作用。结果:茯苓合剂具有抗脂质过氧化(LPO),保护GSH—PX酶活力功能,减少MDA生成。结论:茯苓合剂对冻融血液有保护作用。     

尼可地尔超极化心脏停搏心肌保护的实验研究

目的　比较高钾心停搏液去极化心脏停搏和尼可地尔心停搏液超极化心脏停搏的心肌保护效果。方法　实验分去极化心脏停搏组和超极化心脏停搏组 (每组动物 8只 )。 4℃心停搏液(40ml/kg)诱停离体鼠心 ,每 30分钟重复灌注半量心停搏液 (2 0ml/kg) ,15± 1℃心脏停搏 12 0分钟。记录心脏机械停搏时间、再灌注后心脏复跳情况、心功能指标恢复、冠状循环灌注平均流量、心肌丙二醛 (MDA)含量及心肌细胞超微结构的改变。结果　超极化心脏停搏组对心功能恢复、冠状循环灌注平均流量及心肌组织超微结构的保护效果优于去极化心脏停搏组 (P <0 0 5 ) ,心肌MDA含量低于去极化心脏停搏组 (P <0 0 1)。结论　尼可地尔超极化心停搏液 (10 0mmol/L)心肌保护效果优于高钾去极化心停搏液     

体外循环下冠状动脉搭桥术中的心肌保护

目的 探讨体外循环下冠状动脉搭桥术中的心肌保护方法 .方法 30例体外循环下冠状动脉搭桥术采用经主动脉根部,升主动脉前壁插针荷包固定,间歇温血停搏液顺灌-冷血停搏液顺灌-温血停搏液顺灌,首次灌温4：1氧合血高钾心脏停搏液,待心脏停搏充分后,每间隔30～40分钟再次使用冷4：1氧合血低钾心脏停搏液,开放升主动脉前温4：1氧合血低钾心脏停搏液灌注.结果 开放升主动脉后心脏自动复跳25例,20WS除颤1次后复跳4例, 自动复跳后室颤20WS除颤2次心脏复跳1例.复跳前血钾（4.81±0.45）mmol/L.术后患者均痊愈出院.结论 采用间断经主动脉温血停搏液顺灌-冷血停搏液顺灌-温血停搏液顺灌起到了良好的心肌保护作用,自动复跳率较高.     

肿瘤的液氮冷冻治疗

冷冻在生物学上有两种截然不同的作用:1.促使细胞坏死;2.维持细胞生命。基于此作用而可达到保存组织或破坏组织的目的。影响细胞生死的因素,主要为1.细胞的冷却温度与速度;2.复温速度;3.细胞或组织对低温侵袭的感受性。一般细胞和组织破坏的临界温度为-5℃——-50℃,特别在-20℃左右,Mazur等谓以1,000℃/分极快速度冷却与100℃/分急速复温,可以保存细胞 Schrott提出,倘以100℃/分以下速度缓慢冷冻,即冷冻干燥或加入甘油等吸水物质。使细胞内游离水分丧失,即使温度降至-200℃细胞仍能生存而不破坏。相反,以100℃/分快速冷却与10℃/分缓慢复温,则可使细胞或组织破坏最大。     

氧合晶体停搏液对缺血心肌保护的研究

目的　探讨体外循环中氧合晶体停搏液对缺血心肌的保护作用。方法　实验采用离体兔心灌注模型 ,以 4℃氧合晶体停搏液每隔 30分钟灌注 1分钟 ,在 2 0℃持续停跳 1 80分钟 ,复灌30分钟使兔心复跳。监测其心功能、能量代谢、超微结构等指标。结果　氧合晶体停搏液组的各项指标均显著优于冷钾停搏液组 (P <0 0 1 )。结论　氧合晶体停搏液能显著改善缺血心肌的能量代谢 ,有助于体外循环中的心肌保护。     

蟾蜍肠组织冻融AKPase组化研究

目的：为了探讨组织细胞冻融和低温保存的活性，以实现组织的保存和移植。方法：本实验采用Olympus显微镜观察测定了冻融蟾蜍肠组织碱性磷酸酶(AKPase)活性及茯苓合剂的保护效应。结果：实验表明：-5℃、-18℃、-22℃冻融蟾蜍肠组织经茯苓合剂等渗后碱性磷酸酶(AKPase)具有活性。结论：这为组织的保存和移植提供了临床理论依据．也为药物临床应用提供广阔前景。     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.