纤溶酶对小鼠肺泡上皮液体清除作用的研究

目的探讨纤溶酶对在体小鼠肺泡液体清除率(AFC)的作用。方法应用考马斯亮蓝法测定小牛血清白蛋白浓度的方法测定小鼠在体AFC。结果特异性上皮细胞钠通道阻断剂阿米洛利组能明显降低AFC,气管内注入60μg/mL纤溶酶后,AFC明显增加(38.2±2.1)%,与对照组相比P<0.05,n=6)。纤溶酶+阿米洛利组对AFC的影响与对照组相比差异无统计学意义(P>0.05,n=5),与单独使用纤溶酶比较差异有统计学意义(P<0.05)。结论纤溶酶能明显增加肺泡上皮液体的清除,可能通过增强阿米洛利敏感性钠通道活性而影响AFC。     

羧甲基壳聚糖对肺泡液体清除率的作用研究

目的探讨羧甲基壳聚糖与肺泡液体清除率(Alveolar fluid clearance,AFC)之间的关系,阐明羧甲基壳聚糖是否参与了肺上皮液体转运。方法应用酶标仪测定小牛血清白蛋白浓度的方法测定小鼠在体AFC。结果羧甲基壳聚糖气管内给药对AFC无明显抑制作用。结论羧甲基壳聚糖可能不影响肺泡上皮钠主动转运机能,抑制肺水肿液的吸收。     

硝苯地平对肺泡液体清除率的作用研究

目的探讨硝苯地平与肺泡液体清除率(AFC)之间的关系,进一步阐明硝苯地平所致非心源性肺水肿发生的病理生理学机制。方法应用酶标仪测定小牛血清白蛋白浓度的方法测定小鼠在体AFC。结果硝苯地平气管内给药对AFC无明显抑制作用,为(49±5)%。结论临床上硝苯地平引起的非心源性肺水肿可能不是通过调节肺泡上皮钠主动转运机能,抑制肺水肿液的吸收而起作用的。     

慢性阻塞性肺疾病患者肺泡液体清除作用机制研究

目的本研究旨在探讨慢性阻塞性肺疾病(COPD)患者离体肺段肺泡液体清除率(AFC)的改变及其与环磷酸鸟苷(cGMP)依赖性蛋白激酶2(PKG2)的关系。方法应用临床外科手术肺切除患者的肺段标本,将药物通过插管注入远端肺组织。应用考马斯亮兰法测定肺泡液体内小牛血清白蛋白浓度的方法测定人离体肺段AFC。应用相关酶联免疫试剂盒检测PKG2。结果 COPD患者肺组织AFC增加,PKG2明显高于对照组。结论 COPD患者气道黏液分泌增多肺脏液体清除作用增强,其机制可能与上皮钠通道功能增强有关。     

β3肾上腺素能受体激动剂对离体人肺脏肺泡液体清除的作用

目的：制备离体人肺脏模型,探讨β3肾上腺素能受体激动剂CGP-12177对肺泡液体清除率（AFC）的作用及其机制。方法：以肺泡内Evans蓝标记的白蛋白浓度的变化测定AFC。首先将10^-4 mol/L到10^-7 mol/L的CGP-12177分别灌注到离体人肺脏肺泡腔内,测定AFC的变化。然后将10^-5 mol/L CGP-12177分别与α受体阻滞剂酚妥拉明、β1受体阻滞剂阿替洛尔、β2受体阻滞剂ICI-118551、β3受体阻滞剂SR59230A、钠通道阻断剂氨氯吡咪、Na^＋-K^＋-ATP酶阻断剂哇巴因混合后灌注到离体人肺脏肺泡腔内,测定AFC的变化。结果：10^-7 mol/L和10^-4 mol/L CGP-12177对离体人肺脏肺泡液体清除率没有影响,10^-6 mol/L和10^-5 mol/L的CGP-12177能够显著提高离体人肺脏肺泡液体清除率。CGP-12177增加离体人肺脏AFC的作用能够被SR59230A、氨氯吡咪和哇巴因抑制。结论：高选择性CGP-12177主要通过调节Na^＋-K^＋-ATP酶的活性提高离体人肺脏肺泡液体清除能力。     

右旋美托咪啶对小鼠肺泡上皮液体清除作用的研究

目的探讨右旋美托咪啶与在体小鼠肺泡液体清除率(AFC)之间的关系,以明确其在肺脏液体清除中的作用。方法应用酶标仪测定伊文思蓝标记的小牛血清白蛋白浓度的方法测定小鼠在体AFC。结果与1mmol/L阿米洛利抑制效应相反,气管内注入1.5μg/kg右旋美托咪啶后,能显著增加小鼠在体AFC。与阿米洛利合用后此增强效应受到抑制,表明右旋美托咪啶能够增加与上皮钠通道有关的阿米洛利敏感性AFC。结论临床上对合并肺脏损害的患者进行镇静时,可以考虑右旋美托咪啶对肺脏液体清除作用的影响,应用其进行相应的治疗。     

咪达唑仑对小鼠肺泡上皮液体清除作用的研究

目的探讨咪达唑仑与在体小鼠肺泡液体清除率(AFC)之间的关系,以及β2肾上腺素受体激动剂特布他林对其作用的影响。方法应用酶标仪测定小牛血清白蛋白浓度的方法测定小鼠在体AFC。结果气管内注入0.1mmol/L咪达唑仑后,能显著降低小鼠AFC。与1mmol/L阿米洛利(特异性钠通道阻断剂)合用后抑制效应未见进一步增强,表明咪达唑仑能够抑制与上皮钠通道有关的阿米洛利敏感性AFC。β2肾上腺素受体激动剂特布他林能明显增加小鼠AFC,与咪达唑仑合用后,特布他林几乎完全逆转咪达唑仑对AFC的抑制作用。结论临床上对合并肺脏损害的患者应用咪达唑仑时应考虑其可能对肺脏液体清除作用的影响,必要时可以考虑应用β2肾上腺素受体激动剂特布他林进行治疗。     

间充质干细胞条件培养基对肺泡上皮液体清除能力的影响

目的探讨小鼠骨髓间充质干细胞(BMSCs)条件培养基对小鼠肺泡液体清除的影响和对人肺泡上皮细胞生存能力的作用,并明确小鼠BMSCs条件培养基在肺脏液体清除中的作用机制。方法细胞贴壁法分离培养小鼠BMSCs,应用流式细胞术对小鼠BMSCs的表面标记物进行鉴定;运用酶标仪测定小牛血清白蛋白浓度的方法测定小鼠在体肺泡液体清除率;利用活细胞计数盒(CCK-8)试剂研究小鼠BMSCs条件培养基对人H441肺泡上皮细胞生存能力的影响;采用蛋白质印迹法研究小鼠BMSCs条件培养基对人肺泡上皮细胞钠通道蛋白水平的影响。结果小鼠BMSCs稳定表达CD44,阴性表达CD34;小鼠BMSCs条件培养基能够提升在体小鼠肺泡液体清除率;小鼠BMSCs的条件培养基能够提高人肺泡上皮细胞的生存能力;蛋白质印迹法结果显示小鼠BMSCs条件培养基能够增加人肺泡上皮细胞钠通道的蛋白水平表达。结论小鼠BMSCs条件培养基能够增强肺泡上皮细胞的液体清除并能改善其生存能力,机制可能与肺泡上皮细胞钠通道蛋白表达的增加有关。     

异丙酚和异氟醚后处理对内毒素血症大鼠肺泡液体转运功能的影响

目的 建立内毒素血症大鼠模型,应用异丙酚和异氟醚,以肺组织湿干重比、肺泡液体清除率、肺水通道1为指标,观察肺泡液体转运功能的变化.方法 健康SD大鼠32只,随机分为4组.生理盐水组:尾静脉注射生理盐水;内毒素组、异丙酚组和异氟醚组均静注内毒素.1小时后.异丙酚组泵注异丙酚,异氟醚组持续异氟醚吸入.2小时后取标本,测定肺组织湿干重比、肺泡液体清除率:Western blot法检测水通道1蛋白.结果 各组肺组织湿/干比差异均尤统计学意义.异氟醚组肺泡液体清除率(0.054±0.007)较异丙酚组(0.065±0.006)高;异氟醚组水通道1为(0.53±0.06)较异丙酚组(0.60±0.07)高,均有显著差异(P＜0.05).结论 与异丙酚相比,异氟醚后处理增加内毒素血症大鼠肺泡液体清除率和水通道1蛋白表达.     

不同液体复苏对大鼠急性失血后早期肺的影响

目的 分析临床常用液体对创伤失血性休克液体复苏后肺组织的影响,为创伤失血性休克实施理想的液体复苏治疗提供依据.方法 比较急性失血大鼠以不同液体复苏后血清细胞因子水平、肺通透性指数变化及肺组织形态学改变.结果 乳酸林格氏液(LR)组血清TNF_α,IL-6水平高于其它各组,胶体复苏组支气管肺泡灌洗液(BALF)中蛋白含量明显高于晶体组,病理检查肺泡腔渗出液最明显.结论 急性失血以不同液体复苏后早期即出现程度不同的肺损伤;TNF_α及IL-6是介导此损伤的重要介质;大量胶体复苏后肺泡中蛋白渗出显著增加对此类肺损伤的发展不利.     

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.     

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.     

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.