二甲基乙二酰甘氨酸对大鼠肺缺血-再灌注损伤的保护作用

目的探讨二甲基乙二酰甘氨酸(DMOG)对大鼠肺缺血-再灌注损伤(IRI)的保护作用。方法成年SD大鼠24只均分为三组。采用阻断左肺门60min、再灌注120min制备肺IRI模型(IRI组)。DMOG组予腹腔注射DMOG 60mg/kg后制备肺IRI模型,假手术组(S组)仅游离左肺门,但不阻断。处死大鼠,计算肺组织肺湿干重比(W/D),分光光度法检测肺组织中丙二醛(MDA)含量、髓过氧化物酶(MPO)及超氧化物歧化酶(SOD)活性,ELISA法检测血清TNF-α、IL-1β和IL-6水平,RT-PCR和Western blot检测肺组织缺氧诱导因子1α(HIF-1α)mRNA和蛋白表达量。结果与S组相比,IRI组肺组织W/D、MDA、MPO及TNF-α、IL-1β、IL-6、HIF-1α蛋白相对表达量均升高(P<0.05),而SOD降低(P<0.05)。与IRI组相比,DMOG组W/D、MDA、MPO及TNF-α、IL-1β、IL-6水平均降低(P<0.05),而SOD、HIF-1α蛋白相对表达量均升高(P<0.05)。结论 DMOG预处理可以减轻大鼠早期肺IRI,其调控作用主要发生在HIF-1α基因转录后的蛋白水平。     

谷氨酰胺对肝缺血再灌注导致急性肺损伤肺组织MDA、SOD水平及预后的影响

目的 评价分析谷氨酰胺对肝缺血再灌注导致急性肺损伤肺组织MDA、SOD水平及预后的影响.方法 选取45例行肝肿瘤手术患者作为研究对象,根据随机数表法分为S组(假手术组)、I-R组(缺血-再灌注组)、G组(谷氨酰胺组),每组15例.I-R组完全阻断门静脉、肝动脉、胆总管持续缺血30 min后再进行灌注1 h,G组于全肝血流阻断前1 h静脉滴注0.75 mg/kg谷氨酰胺实施预处理.对3组患者组织超氧化物歧化酶(SOD)、丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)、肺湿/干重比(W/D)、髓过氧化物酶(MPO)活性进行测定,并评估肺组织学评分.结果 与I-R组比较,G组患者肺组织MDA水平、MPO活性、W/D及TNF-α水平降低,SOD水平上升,差异有统计学意义(P<0.05);与S组比较,G组患者肺组织MDA、TNF-α水平、W/D上升,SOD水平降低,差异有统计学意义(P<0.05);I-R组肺组织学评分高于G组、S组,差异有统计学意义(P<0.05).结论 给予肝缺血再灌注导致急性肺损伤进行谷氨酰胺预处理能够有助于抑制炎性因子释放,从而显著增加肺组织表达,改善MDA、SOD水平,利于预后质量.     

腺苷对大鼠肺缺血-再灌注损伤的保护作用

目的探讨腺苷对大鼠肺缺血-再灌注(I-R)损伤的保护作用。方法健康SD大鼠60只,随机均分为假手术(A)组、肺I-R(B)组、腺苷预处理(C)组。建立在体肺I-R模型,检测肺组织中髓过氧化物酶(MPO)活力、丙二醛(MDA)含量、超氧化物歧化酶(SOD)含量,并通过HE染色及透射电镜观察肺组织结构的变化。结果 C组MPO活力、MDA含量明显较B组低,而SOD含量明显高于B组(P<0.05)。HE染色可见B组明显毛细血管淤血、肺泡间质水肿、肺泡压缩;而C组仅见轻度肺泡间质水肿。透射电镜显示B组II型肺泡上皮细胞微绒毛数量减少,核固缩,板层体减少;而C组细胞器完整。结论腺苷对肺I-R损伤有保护作用,可能与抑制中性粒细胞聚集与激活,减轻肺组织水肿,减少氧自由基损害有关。     

姜黄素预处理对肢体缺血再灌注肺损伤大鼠肺内炎症反应的影响

目的研究姜黄素预处理对肢体缺血再灌注肺损伤大鼠肺内炎症反应的影响。方法选取成年♂SD大鼠,建立大鼠肢体缺血2 h再灌注3 h肺损伤模型。随机分为5组(各12只):假手术组及模型组,分别给予等容量生理盐水;3个浓度姜黄素预处理组,分别于缺血前2 h经腹腔注射姜黄素501,00,200 mg.kg-1。测定每组肺组织湿/干重比(W/D),髓过氧化物酶(MPO)活性、肿瘤坏死因子α(TNF-α)、白细胞介素-6(IL-6)含量以及核因子-κB p65(NF-κB p65)的蛋白表达。结果与假手术组比较,模型组的肺组织W/D与MPO活性、TNF-α和IL-6含量并使NF-κB p65表达均明显升高;姜黄素预处理组可剂量依赖地降低肺组织W/D与MPO活性、TNF-α和IL-6含量并使NF-κB p65表达升高。结论姜黄素预处理能减轻肢体缺血再灌注所致的大鼠肺内炎症反应,其机制可能与抑制NF-κB激活、从而减少TNF-α和IL-6介导的中性粒细胞聚集有关。     

缩宫素对大鼠肝脏缺血-再灌注损伤的保护作用及其机制

目的 探讨缩宫素对大鼠肝脏缺血-再灌注(I-R)损伤的保护作用及可能的机制.方法 将48只雌性SD大鼠随机均分为假手术(S)组、I-R组和缩宫素处理(OT)组.建立大鼠70%I-R模型,缺血时间1 h.OT组分别于术前12 h,15 min及再灌注时经腹腔注射缩官索0.5 mg/kg,S组及I-R组在相同时间注射等量生理盐水.各组大鼠分别于肝脏再灌注后2和6 h处死,取肝脏及血液标本,检测血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、肿瘤坏死因子α(TNF-α)以及肝脏组织超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)的活性及丙二醛(MDA)含量,并分别检测肝组织中核因子κB(NF-κB)的表达和肝脏组织的病理改变.结果 与I-R组相比,OT组的ALT、AST、TNF-α水平及MPO、NF-κB阳性表达明显降低(P<0.05),肝脏病理损伤较轻,但是MDA及SOD变化不明显.结论 缩宫素对大鼠肝脏I-R损伤具有保护作用.其机制可能与抑制炎症因子产生及活化有关.     

氨溴索对高浓度氧和通气机联合所致大鼠急性肺损伤的防护作用

目的:研究氨溴索对高浓度氧和通气机联合所致大鼠急性肺损伤的防护作用。方法:将36只雄性SD大鼠随机分为3组。A组实施空气大潮气量通气,B组实施高氧大潮气量通气,C组为氨溴索干预组。测定左肺W/D值,BALF中性粒细胞计数、TNF-α、IL-1β、MIP-2含量以及肺组织MDA、SOD水平。结果:C组大鼠左肺W/D值、BALF中性粒细胞计数、TNF-α、IL-1β、MIP-2含量、肺组织MDA水平较B组显著下降,而SOD水平较B组显著增加。结论:氨溴索对高浓度氧和通气机联合所致大鼠急性肺损伤有较明显的防护作用。     

间充质干细胞对内毒素诱导急性肺损伤大鼠的保护机制研究

目的：探讨间充质干细胞对内毒素诱导急性肺损伤大鼠的保护机制。方法随机选取本实验室养育的实验大鼠105只,采取随机分组形式分成5组,每组21只, A组经尾部注射5mg/kg生理盐水, B组经尾部注射5mg/kg内毒素, C组经尾部注射5mg/kg内毒素＋0.5ml高剂量间充质干细胞（2＆#215;106/ml）, D组经尾部注射5mg/kg内毒素＋0.5ml高剂量间充质干细胞（1＆#215;106/ml）, E组经尾部注射0.5ml高剂量间充质干细胞（2＆#215;106/ml）,观察各组大鼠的肺部组织学形态、肺湿重/干重、肺动脉气血分及炎症反应情况。结果 A组和E组大鼠肺组织未发生显著变化,结构清晰,未出现炎性细胞浸润情况,黏膜上皮表现良好;B组大鼠肺组织出现了严重水肿,肺泡腔存在浆液性渗出液;C组、D组肺组织得到一定保护, C组较D组肺组织结构保持更加完整,水肿、炎性细胞浸润明显较轻。A组、E组W/D、PaO2、PaCO2、MDA、SOD、MPO、TNF-α、IL-1β差异无统计学意义, P〉0.05;B组的W/D、PaO2、PaCO2、MDA、SOD、MPO、TNF-α、IL-1β和其他组均差异具有统计学意义, P〈0.05;C组、D组MDA、MPO、TNF-α、IL-1β显著高于B组, SOD显著低于B组,同时C组W/D、PaO2、PaCO2、MDA、SOD、MPO、TNF-α、IL-1β和D组差异具有统计学意义, P〈0.05。结论给予急性肺损伤大鼠模型高剂量间充质干细胞可改善肺组织结构损伤状况,降低炎性反应,提高肺部通气水平。     

HSPTX复苏对失血性休克大鼠诱发的急性肺损伤的影响

目的:探讨HSPTX(7.5%氯化钠+己酮可可碱)复苏对失血性休克大鼠诱发的急性肺损伤的影响。方法:24只雄性SD大鼠随机分为3组:假失血性休克(Sham)组,乳酸钠林格液(Ringer′s lactate,RL)复苏组,HS+PTX复苏组,每组8只。实验结束时测定各组大鼠肺水含量、支气管肺泡灌洗液(bronchoalveolor lavage fluid,BALF)中中性粒细胞(polymorphonuclear neutrophil,PMN)百分比和总蛋白(total protein,TP)浓度;测定肺组织髓过氧化物酶(myeloperoxidase,MPO)活性,检测肺组织中丙二醛(malondialdehyde,MDA)以及超氧化物歧化酶(superoxide dismutase,SOD)含量;ELISA法测定血浆中肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)、白细胞介素1β(interleukin1β,IL-1β)含量。结果:与Sham组相比,各实验组休克复苏2 h后肺水含量、总蛋白含量、PMN百分比、血浆中TNF-α、IL-1β表达以及肺组织MDA,MPO含量明显增...     

Protective effect of raffinose-low potassium dextran solution on isolated lung in rats

目的 探讨棉籽糖低钾右旋糖酐(R-LPD)液对大鼠离体供肺保存期间不同时间段的保护作用.方法 健康SD大鼠48只,随机分为低钾右旋糖酐(LPD)液(A组)和R-LPD液(B组).建立大鼠离体肺冷保存模型,观察两组肺冷保存4、8、12、24 h四个时间段的效果,检测肺组织湿干重比(W/D)、丙二醛(MDA)含量、髓过氧化物酶(MPO)活性、超氧化物歧化酶(SOD)活性,HE染色观察肺组织病理形态变化.结果 A组肺冷保存24 h,W/D、MDA含量、MPO活性、SOD活性均明显高于冷保存12 h(P＜0.01);B组肺冷保存24 h,MDA含量、MPO活性、SOD活性均明显高于冷保存12 h(P＜0.01).肺冷保存至12h,B组SOD活性高于A组(P＜0.05).肺冷保存至24h,B组W/D、MDA含量、MPO活性明显低于A组(P＜0.05或P＜0.01);而B组SOD活性明显高于A组(P＜0.01).HE染色可见A组肺冷保存至24h肺泡结构破坏,间质水肿明显,呈现严重不可逆性损伤;而B组肺组织结构清晰,仅轻度炎症反应.结论 大鼠离体肺冷保存至24 h,R-LPD液肺保护效果明显优于LPD液.     

当归多糖对免疫性结肠炎大鼠结肠损伤的保护作用研究

目的 研究当归多糖对免疫性结肠炎大鼠结肠损伤的保护作用及机制。方法 建立大鼠免疫性结肠炎模型,灌肠用药21 d后,评价大鼠结肠粘膜损伤指数(CMDI),检测结肠髓过氧化物酶(MPO)与SOD活性,MDA、NO含量及IL-2、TNF-α、IL-10、转化生长因子β(TGF-β)水平,同时检测血浆IL-2、TNF-α、NO水平。结果 当归多糖(250、500、 1000 mg·kg~(-1))灌肠降低模型组大鼠显著升高的CMDI值,MDA、NO含量,MPO活性及IL-2、TNF-α水平,使显著降低的SOD活性,TGF-β、IL-10水平升高,血浆NO水平降低不明显。ASP用药呈一定量效关系。结论 当归多糖通过拮抗氧化、免疫调节、损伤修复作用缓解免疫性结肠炎大鼠炎症反应,减轻结肠损伤。     

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.

     

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.     

2-(Acetoxyphenyl)-(Z)-styryl sulfides as cyclooxygenase inhibitors

2-(Acetoxyphenyl)-(Z)-styryl sulfides are described as selective cyclooxygenase-2 (COX-2) inhibitors, useful for treating inflammation and COX-2-mediated disorders including neoplasia. 2-(Acetoxyphenyl)-(Z)-styryl sulfide is claimed to be the most potent COX inhibitor in the series with a COX-2 selectivity ratio of 33. This compound is also claimed to be superior to celecoxib (Celebrex^®, Pfizer) in inhibiting cell growth of colorectal carcinoma cells. In this evaluation, the COX inhibitory activity of this compound is compared to that previously disclosed for diarylheterocycles and 2-(acetoxyphenyl)alkyl sulfides. The validity of the DLD-1 cell line in the growth inhibition studies is questioned based on recent literature reports indicating the lack of COX-2 expression in this cell line.     

Sleep-disordered breathing with chronic opioid use

Chronic opioid use for pain relief or as substitution therapy for illicit drug abuse is prevalent in our societies. In the US, retail distribution of methadone and oxycodone has increased by 824 and 660%, respectively, between 1997 and 2003. μ-Opioids depress respiration and deaths related to illicit and non illicit chronic opioid use are not uncommon. Since 2001 there has been an emerging literature that suggests that chronic opioid use is related to central sleep apnoea of both periodic and non-periodic breathing types, and occurs in ～ 30% of these subjects. The clinical significance of these sleep-related abnormalities are unknown. This review addresses the present knowledge of control of ventilation mechanisms during wakefulness and sleep, the effects of opioids on ventilatory control mechanisms, the sleep-disordered breathing found with chronic opioid use and a discussion regarding the future research directions in this area.     

Drug targets for cognitive enhancement in neuropsychiatric disorders

The investigation of novel drug targets for treating cognitive impairments associated with neurological and psychiatric disorders remains a primary focus of study in central nervous system (CNS) research. Many promising new therapies are progressing through preclinical and clinical development, and offer the potential of improved treatment options for neurodegenerative diseases such as Alzheimer's disease (AD) as well as other disorders that have not been particularly well treated to date like the cognitive impairments associated with schizophrenia (CIAS). Among targets under investigation, cholinergic receptors have received much attention with several nicotinic agonists (α7 and α4β2) actively in clinical trials for the treatment of AD, CIAS and attention deficit hyperactivity disorder (ADHD). Both glutamatergic and serotonergic (5-HT) agonists and antagonists have profound effects on neurotransmission and improve cognitive function in preclinical experiments with animals; some of these compounds are now in proof-of-concept studies in humans. Several histamine H3 receptor antagonists are in clinical development not only for cognitive enhancement, but also for the treatment of narcolepsy and cognitive deficits due to sleep deprivation because of their expression in brain sleep centers. Compounds that dampen inhibitory tone (e.g., GABA_A α5 inverse agonists) or elevate excitatory tone (e.g., glycine transporter inhibitors) offer novel approaches for treating diseases such as schizophrenia, AD and Down syndrome. In addition to cell surface receptors, intracellular drug targets such as the phosphodiesterases (PDEs) are known to impact signaling pathways that affect long-term memory formation and working memory. Overall, there is a genuine need to treat cognitive deficits associated with many neuropsychiatric conditions as well as an increasingly aging population.