黄芪注射液对内毒素诱导大鼠肠系膜微循环障碍改善作用的实验研究

目的探讨静脉给予黄芪注射液对内毒素血症肠系膜微循环障碍的改善作用。方法 Wistar大鼠30只为对照组、模型组、治疗组,每组10只。采用静脉注入脂多糖（LPS）（5mg·kg-1·h-1）复制内毒素血症模型,治疗组给予静脉注射黄芪注射液（5ml·kg-1·h-1）,用微循环观察系统每20分钟动态观察细静脉粘附白细胞,细静脉血管壁过氧化物的动态变化。在100min观察结束后,计数肠系膜间质内肥大细胞脱颗粒率。取外周血,用流式细胞仪测定粒细胞粘附分子CD11b和CD18的表达。结果模型组在LPS滴注20min后,黏附于大鼠肠系膜细静脉壁上的白细胞数和管壁过氧化物依存的DHR的荧光强度显著增加,100min时计数肠系膜间质内肥大细胞脱颗粒率显著地增加（P〈0.05）。流式细胞仪测定外周血粒细胞黏附分子CD11b和CD18的表达明显增加（P〈0.05）。治疗组白细胞与肠系膜细静脉的血管壁黏附;细静脉壁过氧化物依存的DHR荧光强度的增加,肠系膜间质内肥大细胞脱颗粒率,外周血粒细胞黏附分子CD11b和CD18的表达明显受到抑制（P〈0.01）。结论黄芪注射液对内毒素血症肠系膜微循环障碍有改善作用。可能其抑制粒细胞黏附分子CD11b和CD18表达及肥大细胞脱颗粒相关。     

异丙酚对油酸性急性肺损伤大鼠肺表面活性蛋白A的影响

目的 观察油酸性急性肺损伤(ALI)大鼠肺组织肺表面活性蛋白A(SP-A)的蛋白表达情况及异丙酚对该指标的影响,探讨异丙酚肺保护作用及其机制.方法 80只雄性SD大鼠,体重250～290g,随机分成5组,每组16只:正常对照组(Ⅰ组),ALI组(Ⅱ组),异丙酚低剂量组(Ⅲ组):4mg·kg-1·h-1,异丙酚中剂量组(Ⅳ组):8mg·kg-1·h-1,异丙酚高剂量组(Ⅴ组):16mg·kg-1·h-1.静脉注射油酸250μl·kg-1制备大鼠ALI模型,Ⅲ～Ⅴ组持续静脉输注异丙酚4h之后处死大鼠.取每组8只大鼠肺组织,生化方法测定Na -K -ATP酶活性,RT-PCR测定肺组织SP-AmRNA蛋白表达;其余8只进行全肺支气管肺泡灌洗,留取支气管肺泡灌洗液(BALF),进行白细胞计数.结果 与Ⅰ组比较,Ⅱ组肺组织Na -K -ATP酶活性以及SP-AmRNA蛋白表达均显著减弱;BALF中白细胞数量及中性粒细胞比例均显著增加,淋巴细胞比例显著减少.给予不同剂量异丙酚治疗后(4、8、16mg·kg-1·h-1),与Ⅱ组比较,Ⅲ、Ⅳ、Ⅴ组肺组织Na -K -ATP酶活性均显著增强(P＜0.05),Ⅳ组肺组织SP-AmRNA蛋白表达显著增强(P＜0.05),Ⅴ组肺组织SP-AmRNA蛋白表达显著减弱(P＜0.05),Ⅲ组肺组织SP-AmRNA蛋白表达无显著变化;Ⅲ、Ⅳ、Ⅴ组BALF中白细胞数量及中性粒细胞比例均显著减少(P＜0.05),淋巴细胞比例显著增加 (P＜0.05).结论 异丙酚可以通过抑制油酸性ALI时肺组织的炎性反应,降低肺水肿程度,减轻肺泡Ⅱ型上皮细胞损伤,降低肺组织SP-A降解,促进肺泡SP-A合成与分泌,维持肺泡Ⅱ型上皮细胞正常的结构与功能,从而发挥对油酸性ALI的保护作用.     

异丙酚对氯胺酮所致大脑皮质神经元损害保护作用的机制

目的:观察异丙酚对氯胺酮诱导的cfos基因在大鼠大脑后扣带回皮质区表达的影响,并探讨异丙酚预防或减轻氯胺酮所致精神症状及神经损害的机制。方法:雄性Wistar大鼠30只,随机分为生理盐水5ml组、氯胺酮100mg·kg-1组、异丙酚100mg·kg-1组、异丙酚50mg·kg-1 氯胺酮100mg·kg-1组、异丙酚100mg·kg-1 氯胺酮100mg·kg-1组。异丙酚与氯胺酮用药间隔15min。所用药物用生理盐水配至5ml经腹腔注射。各组动物于用药后2h,断头处死,分离脑组织,用半定量RTPCR技术和免疫组织化学方法检测各组cfosmRNA与cfos蛋白在大鼠后扣带回皮质区表达的变化。结果:氯胺酮可明显诱导cfosmRNA与cfos蛋白在大鼠后扣带回皮质区的表达;异丙酚自身不能诱导cfosmRNA和cfos蛋白的表达;预先给予异丙酚可显著抑制氯胺酮诱导的cfosmRNA和cfos蛋白在这一区域的表达,且抑制效应成剂量依赖性。结论:异丙酚可抑制氯胺酮诱导的cfosmRNA与cfos蛋白在大脑后扣带回皮质区的表达,这可能是其预防或减轻氯胺酮所致精神症状和神经损害的机制之一。     

丙泊酚对内毒素休克兔的保护作用

目的探讨不同剂量丙泊酚对内毒素休克兔的保护作用。方法连续注射LPS复制内毒素休克模型,新西兰大白兔50只,雌雄不限,随机分为5组:正常对照组(A组);内毒素对照组(B组);丙泊酚2mg·kg-1·h-1组(C组);丙泊酚5mg·kg-1·h-1组(D组);丙泊酚10mg·kg-1·h-1组(E组)。C、D、E组均为LPS注入后30min后予丙泊酚持续静脉泵入。5h内观察动物的MAP、PaO2、pH,血清TNF-α。比较48h内存活率。结果与B组比较,C、D、E三组均能不同程度地逆转MAP的下降,降低血清TNF-α水平,降低死亡率(P<0·01或P<0·05)。结论丙泊酚对内毒素休克兔具有保护作用。不同剂量丙泊酚对内毒素休克兔的保护效果不尽相同,并非丙泊酚剂量越大就效果越好。     

曲马多预处理对氯胺酮抗抑郁作用的影响

目的:观察曲马多预处理对氯胺酮抗抑郁作用的影响。方法:32只Wistar大鼠随机分为生理盐水组(S组)、曲马多组(T组)、氯胺酮组(K组)、曲马多+氯胺酮组(T+K组)。药物预处理前1天大鼠强迫游泳15 min;预处理当天各组分别腹腔注射1 mL容积的生理盐水、曲马多5 mg.kg-1、生理盐水、曲马多5 mg.kg-1;30 min后,各组分别注射生理盐水、生理盐水、氯胺酮10 mg.kg-1、氯胺酮10 mg.kg-1;再经30 min后,行强迫游泳试验并记录其不动时间,取海马组织测定脑源性神经营养因子(BDNF)及酪氨酸受体激酶B(TrkB)的含量。结果:与S组相比,K组、T+K组强迫游泳试验不动时间减少,海马BDNF及TrkB表达增加(P<0.05);与K组相比,T+K组强迫游泳试验不动时间减少,海马BDNF及TrkB表达增加(P<0.05)。结论:曲马多预处理能增强氯胺酮的抗抑郁作用,这可能与大鼠海马BDNF及TrkB表达上调有关。     

氯胺酮对未成年大鼠记忆维持及海马p-CREB、c-fos表达的影响

目的 探讨氯胺酮(Ket)对未成年大鼠记忆维持能力及海马磷酸化环腺苷酸应答元件结合蛋白(p-CREB)、c-fos表达的影响及其相关性.方法 筛选合格21日龄SD大鼠72只分为正常对照组、生理盐水组、假训练组、氯胺酮组(根据时间与剂量不同分为四个亚组:Ket1a、Ket1b:分别给与氯胺酮50 mg/kg、100 mg/kg腹腔注射后3 d进行训练).生理盐水组腹腔注射等体积的生理盐水.采用Y型迷宫进行学习记忆能力测试,应用免疫组化法检测海马p-CREB、c-fos的表达.结果 与生理盐水组相比,Ket1a、Ket1b组大鼠记忆维持能力下降(P＜0.05),同时海马神经元p-CREB、c-fos的表达减少(P＜0.05);而Ket3a组、Ket3b组差异无统计学意义(P＞0.05).与正常对照组相比,其余各组海马神经元p-CREB、c-fos表达均增多(P＜0.05).而Ket1a和Ket1b或Ket3a和Ket3b组之间的行为学指标与免疫组化指标差异均无统计学意义(P＞0.05).结论 氯胺酮可能通过抑制未成年大鼠海马p-CREB、c-fos的表达短期影响其记忆维持能力.     

姜黄素对脓毒症大鼠肾组织ICAM-1表达和MPO活性的影响

目的 观察姜黄素对脓毒症大鼠肾组织ICAM-1 mRNA表达、MPO活性的影响,探讨其保护肾功能的可能机制.方法 90只SPF级SD大鼠随机分为假手术组(Sham组)、盲肠结扎穿孔组(CLP组)、姜黄素治疗组(Cur组),CLP组和Cur组进行盲肠结扎穿孔术,Cur组予姜黄素液2mL·kg-1(即100mg·kg-1)腹腔注射,Sham组、CLP组给予2mL·kg-1生理盐水腹腔注射.各组大鼠于术后0、3、6、12、24、48 h 活杀动物取材,观察姜黄素处理后大鼠肾组织ICAM-1 mRNA表达、髓过氧化物酶(MPO)活性及血清尿素氮(BUN)、肌酐(Scr)的变化.结果 CLP术6h后Cur组肾组织ICAM-1 mRNA表达、MPO活性明显低于CLP组(P＜0.05),术后48h血清BUN 、Scr水平亦明显低于CLP组(P＜0.05).结论 姜黄素对脓毒症大鼠肾损伤的保护作用可能与其抑制ICAM-1表达,减少过量中性粒细胞在肾组织中聚集有关.     

内毒素致急性肺损伤大鼠水通道蛋白1、5表达的影响

目的:观察细菌内毒素(LPS)致急性肺损伤(ALI)大鼠肺组织的变化,探讨大鼠急性肺损伤模型的复制.方法:SPF级雄性SD大鼠42只,随机分为ALI组和正常对照组(NS组),每组21只.ALI组子LPS(4 mg·kg-1,浓度4 mg·ml-1)舌下静脉注射;NS组予生理盐水0.2ml舌下静注,动态观察注射后2,6,12 h肺组织湿干质量(W/D)、肺组织病理学改变、支气管肺泡灌洗液(BALF)的细胞总数及中性粒细胞百分比、免疫组化与Western blot法肺组织AQP1蛋白表达的变化.结果:与NS组相比,ALI组大鼠W/D值、BALF细胞总数、中性粒细胞百分比、免疫组化与Western blot法肺组织AQP1、5蛋白表达的变化于LPS静脉注射后2h开始升高,第6 h达高峰.ALI组与NS组各时相点间的差异均具有统计学意义(P＜0.05).结论:静脉注射LPS可导致大鼠ALI,肺炎症损伤反应的高峰于LPS致伤后6～12h最为明显.     

丙泊酚不同麻醉时间对老年大鼠海马CA1区神经元损伤的影响

目的 研究丙泊酚不同麻醉时间对老年大鼠海马CA1区神经元损伤及核因子E2相关因子2/抗氧化反应元件(Nrf2/ARE)信号通路的影响.方法 将36只大鼠分为对照组(生理盐水)、麻醉2 h组(24 mg·kg-1·h-1的丙泊酚维持麻醉2 h)、麻醉4 h组(24 mg·kg-1·h-1的丙泊酚维持麻醉4 h),每组各1...     

急性肺损伤中性粒细胞胶原酶表达异常及甲基强的松龙调控的研究

目的:探讨急性肺损伤时肺组织中性粒细胞胶原酶的表达及甲基强的松龙调控关系。方法:SD大鼠45只,分为3组:1组生理盐水正常对照组,2组内毒素(LPS)致病组,3组内毒素(LPS)+甲基强的松龙组。组2、组3分别由尾静脉注射内毒素(5mg/kg)造成大鼠急性肺损伤模型,组1则注入生理盐水。内毒素(LPS)+甲基强的松龙组在实验造模前2d由腹腔注射甲基强地松龙10mg/kg,1次/d,组1、组2、组3分别于注射后6h建模后各组均取左肺标本,用免疫组织化学法检测肺组织中中性粒细胞胶原酶的表达,并行肺病理损伤评分、肺内中性粒细胞计数,计算肺干/湿质量比。结果:内毒素(LPS)致病组和内毒素(LPS)+甲基强的松龙组高于正常对照组中性粒细胞胶原酶相对含量、肺病理损伤评分、肺干/湿质量比、肺内中性粒细胞计数(P<0.05)。内毒素(LPS)致病组高于内毒素(LPS)+甲基强的松龙组中性粒细胞胶原酶相对含量、肺病理损伤评分、肺干/湿质量比、肺内中性粒细胞计数(P<0.05)。结论:急性肺损伤性粒细胞胶原酶表达异常与肺损伤有密切关系,甲基强的松龙能调控急性肺损伤时中性粒细胞胶原酶的表达异常。     

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.     

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.