牛磺酸对缺血大鼠心肌腺苷三磷酸酶的影响

目的观测牛磺酸（ｔａｕｒｉｎｅ，Ｔａｕ）对心肌缺血损伤时心肌肌膜和线粒体ＡＴＰ酶活性的影响。方法以异丙肾上腺素（Ｉｓｏ，５ｍｇ·ｋｇ－１）诱导心肌缺血损伤模型，用定磷法分别测定Ｃａ２＋－ＡＴＰ酶、Ｍｇ２＋－ＡＴＰ酶及Ｎａ＋，Ｋ＋－ＡＴＰ酶活性。结果与对照组比较，缺血组心肌肌膜和线粒体Ｃａ２＋－ＡＴＰ酶、Ｍｇ２＋－ＡＴＰ酶及Ｎａ＋，Ｋ＋－ＡＴＰ酶活性均降低，在注射ＩＳＰ前３０ｍｉｎ腹腔注射Ｔａｕ（２００ｍｇ·ｋｇ－１），则上述酶活性未见显著性变化。结论Ｔａｕ具有拮抗缺血大鼠心肌肌膜及线粒体Ｃａ２＋－ＡＴＰ酶、Ｍｇ２＋－ＡＴＰ酶及Ｎａ＋，Ｋ＋－ＡＴＰ酶活性降低的细胞保护作用     

氯丙烯对神经细胞胞浆膜和线粒体膜 Ca~(2 )-ATP 酶,Na~ ,K~ -ATP 酶活性的影响

氯丙烯对神经细胞胞浆膜和线粒体膜Ｃａ２＋┐ＡＴＰ酶，Ｎａ＋，Ｋ＋┐ＡＴＰ酶活性的影响张磊谢克勤高树君孙克任（山东医科大学毒理学研究室，济南２５００１２）用鸡胚脑神经细胞研究１－烯丙基氯－３对细胞胞浆膜和线粒体膜Ｃａ２＋－ＡＴＰ酶，Ｎａ＋，Ｋ＋－ＡＴＰ...     

氯胺酮对脑缺血大鼠纹状体DA含量和Na~+,K~+-ATP酶活性的影响

目的研究脑缺血大鼠纹状体多巴胺含量和Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的变化以及ＮＭＤＡ受体拮抗剂氯胺酮对这些变化的影响。方法采用大鼠４－Ｖ－Ｏ造成急性脑缺血模型，缺血１０ｍｉｎ后分别应用ＨＰＬＣ－ＥＣＤ和比色法测量纹状体ＤＡ含量以及Ｎａ＋，Ｋ＋－ＡＴＰ酶活性。结果脑缺血前１５ｍｉｎ腹腔注射氯胺酮（２５ｍｇｋｇ－１和５０ｍｇｋｇ－１）能明显拮抗脑缺血时ＤＡ含量和Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的降低。结论氯胺酮可通过阻断ＮＭＤＡ受体，抑制纹状体ＤＡ释放和Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的降低，对抗脑缺血损伤。     

自发性高血压大鼠红细胞膜ATP酶活性的研究

以鼠龄相近、体重无差异的１８只Ｗｉｓｔａｒ大鼠作对照，测定了１９只ＳＨＲ红细胞膜Ｃａ＾２＋－ＡＴＰ及Ｎａ＾＋、Ｋ＾＋－ＡＴＰ酶活性、血浆离子钙、血清总钙及２４小时尿钙水平。结果显示，ＳＨＲ红细胞膜Ｃａ＾２＋－ＡＴＰ酶活性较对照组显著降低（Ｐ〈０．０１）。与对照组相比，ＳＨＲ红细胞膜Ｎａ＾＋、Ｋ＾＋－ＡＴＰ酶活性降低（Ｐ〈０．０１）但少数（２／１９）可在高水平。两酶活性均与鼠收缩压呈负相关。ＳＨＲ血     

氯胺酮对大鼠大脑皮质、脑干、纹状体和海马Na~＋，K~＋－ATP酶活性的影响

大鼠ｉｐ不同剂量的氯胺酮（５０，１００，２００ｍｇ·ｋｇ－１），除小剂量（５０ｍｇ·ｋｇ－１）兴奋大脑皮质Ｎａ＋．Ｋ＋－ＡＴＰ酶活性外，其余剂量对鼠脑４个分区的酶活性均有抑制作用．５０ｍｇ·ｋｇ－１氯胺酮显著抑制海马Ｎａ＋，Ｋ＋－ＡＴＰ酶，１００ｍｇ·ｋｇ－１显著抑制大脑皮质、纹状体和海马Ｎａ＋，Ｋ＋－ＡＴＰ酶；２００ｍｇ·ｋｇ－１显著抑制脑干和海马Ｎａ＋，Ｋ＋－ＡＴＰ酶。结果提示．氯胺酮对中枢神经系统的抑制作用可能与其抑制脑组织中Ｎａ＋，Ｋ＋－ＡＴＰ酶活性有关。     

对妊高征患者红细胞膜脂质过氧化和离子运输功能的观察

目的：对妊高征患者红细胞膜过氧化脂质（ＬＰＯ）含量、超氧化物歧化酶（ＳＯＤ）活性、Ｎａ＾＋－Ｋ＾＋－ＡＴＰ酶活性及膜内面Ｃａ＾２＋结合能力的变化进行研究。方法：检测１９名正常妇孕,１９例妊高征患者红细胞膜ＬＰＯ、ＳＯＤ、Ｎａ＾＋－Ｋ＾＋－ＡＴＰ酶活性（比色法）及膜内面Ｃａ＾２＋结合力（原子吸收法）。结果：（１）妊高征组红细胞膜ＬＰＯ含量明显高于正常孕妇组（Ｐ〈０．００１）。（２）妊高征组红细胞膜Ｓ     

汉防己甲素对大鼠急性缺血性肾衰的保护作用

为观察汉防己甲素（Ｔｅｔ）对急性缺血性肾衰的保护作用。术前３ｄ开始每天１次及术前Ｉｈ分别予大鼠ｉｇ汉防已甲素２０ｍｇ／ｋｇ、４０ｍｇ／ｋｇ。然后制作大鼠肾脏缺血再灌注致急性缺血性肾衰模型，测定肾组织中ＭＤＡ、ＳＯＤ、Ｎａ＋－Ｋ＋－ＡＴＰ酶和Ｃａ２＋－ＡＴＰ酶含量及切片观察肾脏形态。结果缺血再灌注后肾组织中ＭＤＡ明显升高，ＳＯＤ、Ｎａ＋－Ｋ＋－ＡＴＰ酶和Ｃａ对－ＡＴＰ酶均显著降低；再灌注组肾小管上皮明显变性而用药组ＭＤＡ显著下降，ＳＯＤ和ＡＴＰ酶均明显升高，肾小管上皮仅见轻度水肿变性。提示汉防己甲素对急性缺血性肾衰有保护作用。     

云南甘草总皂甙对氧自由基诱导羊心肌细胞膜Na~＋，K~＋－ATP酶活性降低的保护作用

云南甘草总皂甙对正常羊心肌细胞膜Ｎａ＋，Ｋ＋－ＡＴＰ酶活性无影响；但对氧自由基诱导羊心肌细胞膜Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的降低有明显保护作用，随浓度增高，酶的活性逐渐升高。与对照组比较，总皂甙浓度为０．２ｍｇ·Ｌ－１时，酶的活性恢复２７．９％，浓度为０．８ｍｇ·Ｌ－１，酶的活性恢复４６．６％。     

汉防已甲素对大鼠急性缺血性肾衰的保护作用

目的 研究汉防已甲素对急性缺血性肾衰的保护作用。方法 术前 ３ｄ开始每天 １次及术前 １ｈ ｉｇ汉防已甲素 ２０ｍｇ／ｋｇ、４０ ｍｇ／ｋｇ。然后制作大鼠肾脏缺血再灌注致急性缺血性肾衰模型，测定肾组织中 ＭＤＡ、ＳＯＤ、Ｎａ＋，Ｋ＋－ＡＴＰ酶和Ｃａ２＋－ＡＴＰ酶含量及切片观察肾脏形态。结果 缺血6０ｍｉｎ再灌注２０ｍｉｎ后肾组织中 ＭＤＡ明显升高，ＳＯＤ、Ｎａ＋、Ｋ＋－ＡＴＰ酶和 Ｃａ２＋－ＡＴＰ酶均显著降低。用药组 ＭＤＡ显著下降，ＳＯＤ和 ＡＴＰ酶均明显升高。病理结果提示再灌注组肾小管上皮明显变性，而用药组损害明显减轻。结论 汉防已甲素对急性缺血性肾衰有一定的保护作用。     

间硝苯地平对老龄肾性高血压大鼠心肌和脑微粒体Na~＋，K~＋－ATP酶，Ca~

间硝苯地平（ｍ－Ｎｉｆ，ｉｇ２０ｍｇ·ｋｇ－１·ｄ１持续给药９周）可显著降低老龄肾性高血压大鼠（ＲＶＨＲ）血压和左室重量（Ｐ＜０．０１），增高心、脑微粒体Ｎａ＋，Ｋ＋－ＡＴＰ酶和Ｃａ２＋－ＡＴＰ酶活性（Ｐ＜０．０１），降低Ｍｇ２＋－ＡＴＰ酶活性，体外量效关系研究发现，ｍ－Ｎｉｆ在较高剂量（１０～１０００μｍｏｌ·Ｌ－１）时可增高ＲＶＨＲ心脑微粒体Ｎａ＋，Ｋ＋－ＡＴＰ酶和Ｃａ２＋－ＡＴＰ酶活性，且随剂量增加而增高。上述结果表明，ｍ－Ｎｉｆ可改善老龄ＲＶＨＲ心脑微粒体Ｎａ＋，Ｋ＋泵和Ｃａ２＋泵功能。     

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.