氟伐他汀对糖尿病肾病鼠血管内皮生长因子表达的影响

目的：探讨氟伐他汀对糖尿病肾病（DN）大鼠肾组织血管内皮生长因子（VEGF）mRNA及蛋白质表达的影响。方法：SD大鼠分为对照组、DN组、氟伐他汀治疗组，链脲菌素腹腔注射诱导DN大鼠模型，诱导成功后氟伐他汀治疗组给予氟伐他汀经胃管灌服。试验12周末检测大鼠体重、血糖、尿肌酐、24h尿白蛋白。采用RT—PCR检测VEGFmRNA及免疫组化检测蛋白质的表达。结果：DN组大鼠体重、血糖、尿白蛋白，VEGFmRNA及蛋白质的表达，肾小球细胞数，细胞外基质（ECM）聚积均高于对照组（P〈0．01）。与DN组相比，氟伐他汀治疗组大鼠体重、血糖、尿白蛋白，肾脏VEGFmRNA及免疫组化检测蛋白质的表达，ECM聚积显著降低（P〈0．01或P〈0．05）。尿VEGF与尿白蛋白呈正相关（r=0．42，P=0．039），与尿肌酐亦呈正相关（r=0．35，P=0．043）．结论：VEGF表达增加可能参与DN的发病机制。氟伐他汀可减轻DN大鼠体重、血糖，减少尿白蛋白的排泄，抑制肾小球系膜增殖及硬化，降低VEGFmRNA及蛋白质的表达。     

替米沙坦对糖尿病大鼠肾脏肾素受体表达的影响

目的：研究替米沙坦对链脲佐菌素糖尿病大鼠肾脏肾素受体表达的影响。方法：18只雄性Wistar大鼠随机分为对照组（N组）、糖尿病组（DM组）、替米沙坦组（T组）。大鼠左下腹腔注射链脲佐菌素60mg·kg-1建立糖尿病模型。测定第4，8周尿蛋白。8周后心脏取血检测血糖、血肌酐、血钠、血钾；取肾脏行PAS染色观察病理改变；免疫组化检测肾脏肾素受体表达水平；RT—PCR检测肾脏肾素受体mRNA表达水平；western blot检测肾素受体表达情况。结果：4周和8周时DM组大鼠24h尿蛋白较N组显著升高（P〈0．05或P〈0．01），T组24h尿蛋白与DM组相比明显降低（P〈0．01）；DM组8周时肾小球损伤指数明显高于N组（P〈0．05），T组则明显低于DM组（P〈0．05）；免疫组化、RT—PCR以及Westernblot检测显示T组肾素受体表达较DM组显著降低（P〈0．05），而N组和DM组肾素受体表达没有明显差异（P〉0．05）。结论：替米沙坦可能部分通过抑制肾素受体的表达减轻早期糖尿病大鼠肾脏损伤。     

补肾降浊颗粒对大鼠糖尿病肾病模型肾脏保护作用

目的观察补肾降浊颗粒对大鼠糖尿病肾病模型肾脏的保护作用。方法采用腹腔注射链脲佐菌素法诱发糖尿病肾病大鼠模型，将人选大鼠随机分为5组，每组30只：阳性药对照组（开搏通14mg·kg^-1·d^-1）、补肾降浊颗粒大剂量组（10．4g·kg^-1·d^-1）、补肾降浊颗粒中剂量组（5．2g·kg^-1·d^-1）、补肾降浊颗粒小剂量组（2．6g·kg^-1·d^-1）和模型对照组，同时设正常对照组24只。给药组分别灌胃给药，每日一次，连续12周。模型对照组和正常对照组在同等情况下给予蒸馏水。每隔4周测定体重、血糖、血肌酐和尿肌酐、24小时尿蛋白排泄量、计算内生肌酐清除率。实验8周末、12周末每组随机处死10只大鼠称双肾重量，计算肾指数，并通过电镜观察肾组织病理结构改变。结果实验12周末补肾降浊颗粒能够改善糖尿病肾病大鼠的一般状态，增加体重；减少24h尿蛋白排泄量，与模型对照组比较有显著性差异（P〈0．01）；降低血肌酐及肌酐清除率，与模型对照组比较有显著性差异（P〈0．05）；抑制肾脏肥大，改善肾脏病理改变；结论补肾降浊颗粒能够抑制糖尿病肾病大鼠肾脏肥大及高滤过，降低24h尿蛋白排泄量，改善肾脏病理结构，对肾脏具有保护作用。     

缬沙坦对2型糖尿病大鼠肾脏抗氧化应激作用机制的研究

目的：观察缬沙坦对实验性2型糖尿病大鼠肾脏病变的保护作用及其机制。方法：链脲佐菌素（STZ）诱导的糖尿病肾病大鼠模型随机分为对照组糖尿病组及治疗组（缬沙坦10mg·kg^-1·d^-1），治疗6周后，比较各组大鼠肾组织中丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性，同时检测各组大鼠血糖、血肌酐、尿素氮、24h尿蛋白定量等。采用RT-PCR方法检测P22phoxmRNA表达。结果：治疗组较非治疗组明显改善尿白蛋白、尿素氮水平和肾脏肥大指数。肾脏MDA含量明显下降（P〈0．05），SOD活性显著上升（P〈0．05）。p22phox的mRNA相对含量在糖尿病组为（0．875±0．94），明显高于单切对照组（0．297±0．067）（P〈0．01），在治疗组为（0．484±0．064），较糖尿病组显著降低（P〈0．01），但仍高于对照组（P〈0．05）。结论：缬沙坦对2型糖尿病肾脏病变有一定的保护作用，其机制可能是通过抑制氧化应激反应，下调糖尿病大鼠P22phoxmRNA的表达对2型糖尿病模型大鼠肾脏产生保护作用。     

贞清方对2型糖尿病大鼠肾脏病变的防治作用及其机制

目的：探讨中药贞清方对2型糖尿病大鼠肾脏病变的防治作用及其机制。方法：采用高糖高脂饲料喂养加小剂量链脲佐菌素注射的方法建立2型糖尿病模型。将成模大鼠随机分成模型组，贞清方高、低剂量组，并设立正常对照组。治疗持续8周。研究贞清方对血糖、尿微量白蛋白排泄率（UAER）、肾质量指数、肾脏病理改变和图像分析结果的影响，并用免疫组织化学方法检测贞清方治疗后基质金属蛋白酶-9在肾脏的表达情况。结果：贞清方能显著降低糖尿病大鼠的空腹血糖和餐后血糖，贞清方高、低剂量组的UAER、肾重指数较模型组明显降低（P〈0．01，P〈0．05），而基质金属蛋白酶9的表达明显增强（P〈0．01，P〈0．05）。病理检查结果：模型组HE染色显示肾小球体积增大，PAS染色显示系膜区基质中度增生以及毛细血管基底膜增厚；贞清方组上述病理变化较模型组明显减轻。图像分析显示：贞清方高、低剂量组肾小球细胞外基质相对面积较模型组降低（P〈（1．01，P〈0.05）。结论：贞清方能明显改善2型糖尿病大鼠的肾脏病理改变、降低UAER，以高剂量组的作用更明显，可能与其降低血糖及调节基质金属蛋白酶9的表达有关。     

达肝素钠对糖尿病大鼠肾脏的作用及机制研究

目的观察达肝素钠对糖尿病大鼠肾脏的保护作用及其机制。方法 Wistar大鼠40只,随机选10只为对照组（A组）,随机选30只大鼠采用腹腔注射链脲佐菌素（STZ）构建大鼠糖尿病模型并随机分为糖尿病组（B组）、低剂量（100 U/kg）达肝素钠组（C组）和高剂量（500 U/kg）达肝素钠组（D组）,每组10只。分别于第8周及第12周检测各组大鼠的空腹血糖（FPG）、24 h尿白蛋白、血肌酐（Scr）及尿肌酐,并计算内生肌酐清除率（Ccr）;制备肾匀浆,并检测血清及肾匀浆丙二醛（MDA）、超氧化物歧化酶（SOD）。结果 1 B、C、D组大鼠FPG均高于A组（P〈0.05）。B、C、D组的24 h尿白蛋白量及Scr均高于A组,Ccr均低于A组（P均〈0.05）;2各组大鼠血清及肾匀浆MDA、SOD的差异均有统计学意义（P〈0.05）。B组MDA含量高于A组（P〈0.05）,SOD低于A组（P〈0.05）。给予达肝素钠可显著降低糖尿病（DM）大鼠MDA,升高SOD的活性,且D组更显著（P〈0.05）。结论 1达肝素钠对糖尿病大鼠具有肾脏保护作用,其机制可能与降低糖尿病大鼠MDA,升高SOD表达,降低尿蛋白等因素有关。2达肝素钠对糖尿病大鼠的肾脏保护作用可能与剂量有关。     

来氟米特对糖尿病肾病大鼠肾脏VEGF表达的影响

目的：研究氟米特对糖尿病肾病大鼠肾脏血管内皮生长因子（VEGF）表达的影响。方法：将48只清洁级雄性Wistar大鼠随机分为正常对照组（A组）、模型对照组（B组）、来氟米特组（C组）和氯沙坦组（D组）。分别于糖尿病成模后8、12周处死,观察24h尿蛋白排泄量、尿素氮（BUN）、肌酐（Scr）、肾脏病理组织学改变、免疫荧光检测肾组织VEGF蛋白的表达,RT—PCR方法检测肾组织VEGF mRNA表达。结果：8、12周末糖尿病模型大鼠（B、C、D组）的Scr、BUN及24h尿蛋白较正常对照组（A组）均有显著增高（P〈0．01）;12周末时B、C、D组大鼠的Scr、BUN及24h尿蛋白均较8周时有所增加;来氟米特（LEF）干预组及氯沙坦干预组上述指标均低于B组,差异有统计学意义（P〈0．01）．但LEF干预组及氯沙坦干预组之间差异无统计学意义。结论：来氟米特和氯沙坦均对糖尿病大鼠肾脏损害有保护作用,其机制可能是通过增加VEGF表达而实现。     

吡格列酮调节糖尿病鼠肾小球肝素酶的表达

目的：观察胰岛素增敏剂吡格列酮对糖尿病大鼠肾小球肝素酶的表达,探讨其肾脏的保护作用及其机制。方法：将雌性SD大鼠分为3组：正常对照组（NC,n=10）、糖尿病组（DM,n=12）和吡格列酮组（DP,n=12）。链脲菌素腹腔注射诱导糖尿病大鼠模型。实验第6周,测定血糖（BG）、糖化血红蛋白（GHb）,血尿素氮（BUN）、血肌酐（Scr）,24h尿蛋白（24hUP）、尿足细胞（UPC）排泄水平。RT-PCR检测肾小球肝素酶mRNA的表达,肾小球间接免疫荧光分析肝素酶的表达分布。结果：与DM组相比,DP组BG、GHb、BUN、Scr水平显著降低（P〈0．01）;24hUP、UPC排泄量亦明显减少（P〈0．05）;肝素酶mRNA的表达及平均吸光度值显著降低（P〈0．05）。结论：吡格列酮可抑制肝素酶的表达,减轻蛋白尿,对糖尿病肾脏病变有保护作用。     

糖尿病大鼠肾皮质节活化正常T细胞表达与分泌因子和desmin表达及其干预的研究

目的：研究糖尿病大鼠肾皮质RANTES和desmin表达及雷公藤内酯醇对其干预作用。方法 SD大鼠随机分为正常组（ NG）、模型组（ DM）和小、大剂量雷公藤内酯醇组（T1,T2：0．2,0．4 mg? kg－1）,灌胃。实验第4,8,12周,检测各组5只大鼠的血糖、肾重、24 h尿白蛋白;同时观察肾皮质中RANTES和demin mRNA的表达。结果 DM组,肾皮质RANTES和demin的表达在第4,8,12周较NG组显著升高（ P ＜0．05）,且从第4周末起,逐渐增高到12周末（ P ＜0．05）;T1、T2组较DM组表达量显著降低（ P ＜0．01）;且T2组较T1组各周的表达更低（ P＜0．05）;从第4周末起,T1组的RANTES mRNA表达逐渐下降至12周末（ P＜0．05）;与第4周末相比,T2组的RANTES mRNA表达在第12周末显著下降（ P＜0．01）;T1组和T2组的desmin mRNA表达在第12周末均较第4周末均显著下降（ P＜0．05）。 DM组RANTES mRNA的表达与desmin mRNA的表达和24 h尿蛋白显著正相关。结论雷公藤内酯醇可能通过抑制糖尿病大鼠肾皮质RANTES的过度表达,缓解足细胞损伤,减轻蛋白尿。     

姜黄素对实验性糖尿病大鼠肾脏蛋白激酶C移位活化的抑制作用

目的探讨姜黄素对实验性糖尿病大鼠肾脏蛋白激酶C（PKC）由细胞浆到细胞膜移位活化的抑制作用。方法 36只大鼠随机分为正常对照组（A组）、糖尿病组（B组）及姜黄素治疗组（C组）,每组12只。采用腹腔单剂量注射链脲佐菌素（STZ）65mg/kg建立糖尿病大鼠模型。C组给予姜黄素30mg·kg-1·d-1腹腔注射。实验第3周、第6周3组分别宰杀6只大鼠,并检测24h尿白蛋白排泄率（UAER）、肌酐清除率（Ccr）及肾重/体重;采用酶联免疫吸附法（ELISA）测定PKC活性。结果 B组UAER、Ccr、肾重/体重及肾脏细胞膜PKC活性均明显升高（P〈0.05或〈0.01）,C组大鼠上述指标均明显下降（P〈0.05或〈0.01）。结论姜黄素通过抑制糖尿病大鼠肾脏细胞PKC移位活化而对糖尿病大鼠早期肾脏病变有保护作用。     

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.