体外"心肌样"环境下5-氮胞苷诱导大鼠骨髓间充质干细胞向心肌样细胞分化

目的探讨在体外"心肌样"环境下5-氮胞苷(5-Aza)诱导能否促进骨髓间充质干细胞(BMSCs)向心肌样细胞分化。方法(1)分离、纯化大鼠BMSCs,分组后用5-Aza诱导部分BMSCs。(2)BMSCs标记后与乳鼠心肌细胞共培养。(3)免疫荧光法鉴定BMSCs的肌球蛋白重链(MHC)和心肌特异性肌钙蛋白I(cTnI)。结果免疫荧光结果显示5-Aza单次诱导组与未诱导组比较MHC、cTnI阳性率显著增加,且5-Aza双次诱导组较单次诱导组MHC、cTnI阳性率显著增加。结论(1)体外"心肌样"环境下5Aza能够促进BMSCs向心肌样细胞分化。(2)5-Aza双次诱导较单次诱导效果更好。     

骨髓间质干细胞向心肌样细胞分化的研究

目的：诱导骨髓间质干细胞（BMSCs）向心肌样细胞分化，为 BMSCs 心肌再生移植治疗提供基础。方法取第5代的 BMSCs，5-氮杂胞苷诱导24 h，显微镜下进行形态学观察，3周后通过 RT - PCR 检测心肌蛋白 desmin 和αMHC 的表达。结果 BMSCs 经5-氮杂胞苷诱导后，细胞形态发生变化，出现肌管结构，RT - PC R 检测结蛋白（desmin ）和αMHC 的表达阳性。结论在体外成功诱导 BMSCs 分化成为心肌样细胞。     

中药诱导间充质干细胞向神经细胞分化后的免疫调控作用

目的:探讨多种中药成分体外定向诱导骨髓间充质干细胞(MSCs)向神经元样细胞分化,并研究分化细胞的免疫调控能力.方法:通过贴壁法分离人骨髓间充质干细胞(hMSCs),体外扩增培养.多种中药成分定向诱导分化为神经元样细胞.光镜下观察细胞形态,免疫细胞化学检测神经细胞特异性抗原标志物神经元烯醇化酶(NSE)、巢蛋白(Nestin)、胶质纤维酸性蛋白(CFAP)的表达.通过单向混合淋巴细胞反应(MLR),观察神经细胞分化的hMSCs对人外周血T淋巴细胞(human peripheral blood lymphocyte,hPBL)免疫调控作用.结果:hMSCs可通过贴壁法成功分离并可在体外大量扩增.黄芪,天麻,人参诱导1～3小时后大部分hMSCs转变为神经元样细胞,出现胞体和突起.免疫细胞化学染色NSE及Nestin呈阳性,GFAP阴性.混合培养结果显示分化hMSCs抑制hPBLs增殖反应.结论:多种中药成分和中药制剂可在体外诱导hMSCs分化为神经元样细胞,分化hMSCs抑制人淋巴细胞增殖反应,具有免疫词控作用.     

体外培养成人脂肪间充质干细胞生物学特性及诱导分化为心肌细胞的研究

目的通过分离、培养脂肪间充质干细胞观察其生物学特性及诱导分化为心肌细胞,为心肌再生提供良好的干细胞来源。方法胶原酶消化分离成人脂肪来源的间充质干细胞并进行传代培养,倒置相差显微镜观察细胞形态,流式细胞仪测定CD29、CD31、CD34、CD44及细胞周期,MTT绘制细胞生长曲线。用第3代细胞进行诱导分化,观察不同浓度5-氮杂胞苷(5-Aza,1,3,5,10,15,20μmol/L)及不同作用时间(12,24,48,72h)诱导其向心肌细胞分化的差别,采用最佳浓度10μmol/L,最佳作用时间24h进行实验,分别在第7,14,21,28天用免疫细胞荧光染色鉴定心肌细胞α-横纹肌、肌球蛋白重链(MHC)、心肌肌钙蛋白I(cTnI)表达,第14天反转录-聚合酶链反应(RT-PCR)法检测心肌发育相关基因NKX2.5的表达。结果倒置相差显微镜下观察原代细胞,可见细胞呈梭型、核圆形或椭圆形,偶见双核。传代细胞核原代细胞形态相似,排列有了一定的方向性。流式细胞仪检测结果显示,第1、3、5代细胞均高表达CD29和CD44;而CD31始终表达很弱,可认为呈阴性表达;CD34在第1、3代细胞弱表达,在第5代细胞表达逐渐减弱为阴性。细胞生长曲线显示前3d处于细胞潜伏状态,第4天进入对数生长期,第10天达到顶峰。细胞周期检测结果显示G1期细胞为85.93%,S期为7.24%,G2期为6.83%。10μmol/L5-Aza诱导后7d进行免疫细胞荧光染色,未见有α-横纹肌、MHC、cTnI表达。14d少量细胞α-横纹肌和MHC阳性表达,cTnI阴性表达。21d表达α-横纹肌和MHC的细胞数量增多,并可见少量cTnI阳性表达。28dα-横纹肌、MHC、cTnT阳性表达数目均增多,RT-PCR结果显示NKX2.5呈阳性表达。结论成人脂肪中可以分离出脂肪间充质干细胞并且可以在体外培养传代,经过5-Aza的诱导可以向心肌细胞分化,为干细胞移植治疗和组织工程学种子细胞提供了更多的选择。     

不同浓度地塞米松对人骨髓间充质干细胞体外增殖及凋亡的影响

目的观察地塞米松对体外培养人骨髓间充质干细胞增殖及凋亡的影响。方法利用1.073g/mLPercoll分离液以梯度密度分离法获取人骨髓间充质干细胞（hMSCs）,进行体外培养。成骨诱导组细胞用地塞米松、抗坏血酸和β-甘油磷酸钠处理,分别进行ALP染色和矿化结节染色。实验组细胞分别以10^-9mol/L、10^-8mol/L、10^-7mol/L和10^-6mol/L地塞米松加以干预,MTT法检测各组细胞的增殖率;流式细胞仪定量分析hMSCs的凋亡率。结果成骨诱导组细胞ALP染色和矿化结节染色均为阳性,对照组为阴性;低浓度（10^-9mol/L）地塞米松对细胞的体外增殖无明显影响（P〉0.05）,10^-8mol/L及以上浓度地塞米松可明显抑制细胞的增殖（P〈0.01）;hMSCs凋亡率随地塞米松浓度的增加而升高（P〈0.01）。结论地塞米松、抗坏血酸和β-甘油磷酸钠可促使hMSCs成骨分化,10^-8mol/L及以上浓度的地塞米松可明显抑制细胞的增殖,地塞米松能促进体外培养的人骨髓间充质干细胞凋亡。     

全骨髓法分离培养骨髓间充质干细胞及向神经样细胞分化的研究

目的 目前尚缺乏标准的骨髓间充质干细胞(BMSCs)的分离方法 ,实验通过全骨髓培养法分离纯化骨髓间充质干细胞,并诱导分化为神经样细胞,以寻找一种简便、实用的分离方法 .方法 取大鼠骨髓.全骨髓培养法结合差速贴壁法分离纯化大鼠骨髓间充质干细胞,传代扩增.倒置相差显微镜下观察骨髓间充质干细胞形态及生物学特点,免疫组化染色鉴定细胞.用MTT法间接测定不同代数细胞活力.诱导分化.先用碱性成纤维细胞生长冈子(bFGF)预诱导24h,然后加入丁羟基茴香醚诱导(BHA)和二甲基亚砜(DMSO)诱导.观察诱导过程中细胞的形态变化,并用免疫组化染色法鉴定细胞.结果 全骨髓培养法成功分离培养BMSCs,免疫荧光染色示CD90、CD71、CD106表达阳性.CD45阴性.MTT法检测细胞活力示2、4、6代细胞于酶标仪490 nm波长处吸光度值均高于第8、10代细胞.细胞经诱导后,细胞呈神经样细胞形态,并且神经元特异性表面标志β微管蛋白(β-Ⅲ-Tubulin)、巢蛋白(Nestin)、神经元特异性烯醇化酶(NSE)表达阳性.结论 采用全骨髓培养法可获得较纯化的骨髓间充质干细胞,其在适宜的诱导分化条件下可诱导分化为神经样细胞.     

地塞米松对人骨髓间充质干细胞增殖、成骨分化及凋亡的影响

目的观察地塞米松对体外培养人骨髓间充质干细胞增殖、成骨分化及凋亡的影响。方法利用Percoll分离液以梯度密度分离法获取人骨髓间充质干细胞（hMSCs）,体外培养时分别以10-9、10-8、10-7和10-6mol/L地塞米松加以干预,MTT法检测各组细胞的增殖率;测定各组的碱性磷酸酶（ALP）活性;流式细胞仪定量分析hMSCs凋亡率。结果低浓度（10-9mol/L）地塞米松对细胞增殖无明显抑制（P〉0.05）,10-8mol/L及以上浓度地塞米松可明显抑制细胞的增殖（P〈0.01）;低浓度（10-9mol/L）地塞米松对ALP的表达无明显影响（P〉0.05）,而高浓度（≥10-8mol/L）地塞米松可明显增加ALP的活性（P〈0.01）,其ALP可达到对照组的2～3.5倍;hMSCs凋亡率随地塞米松浓度的增加而升高（P〈0.01）。结论10-8mol/L及以上浓度的地塞米松可显著hMSCs成骨分化,同时可抑制细胞的增殖并促进细胞凋亡。     

不同浓度5-氮胞苷体外诱导人骨髓间充质干细胞转化为心肌样细胞

为确定5-氮胞苷诱导人骨髓间充质干细胞（MSCs）转化为心肌细胞的合适浓度,取人肋骨来源的骨髓,分离、提纯、培养MSCs,应用0、2．5、5、10、20、40、80μmol／L5-氮胞苷对第2代的MSCs诱导24h,于诱导后1、2、3、4周进行细胞形态学观察;于诱导后2周进行免疫组化鉴定及心肌样细胞转化率的计算和比较。结果表明,5-氮胞苷诱导24h后,小于10μmol／L组仅有少量细胞死亡,其余组约30％细胞死亡;2～3周,相邻细胞间胞膜有接触,逐渐相连呈肌管状;同期未经诱导的MSCs没有出现类似改变。诱导后2周MSCs免疫组化染色,对照组与2．5μmol／L组cTnI表达为阴性,其它组cTnI表达呈阳性。心肌样细胞转化率10μmol／L、20μmol／L、40μmol／L、80μmol／L组之间无明显差异,均明显高于5μmol／L组（P〈0．05）。结论：在体外5-氮胞苷可诱导人MScs转化为心肌样细胞,10μmol／L可能是一种合适的诱导浓度。     

IGF2在小鼠胚胎干细胞定向分化为胰岛样细胞过程中的表达

【摘要】目的观察印迹基因胰岛素样生长因子（IGF）2在小鼠胚胎干细胞定向诱导分化为胰岛样细胞过程中的表达情况。方法体外诱导胚胎干细胞向胰岛样细胞分化,逆转录-PCR（RT-PCR）和细胞免疫荧光检测胰岛细胞标志基因表达;聚合酶链式反应-限制性内切酶片段长度多态性(PCR-RFLP)检测印迹基因IGF2在诱导分化前后细胞中的亲本表达情况。结果诱导分化终末细胞能表达胰岛素、胰高糖素及C肽等胰岛细胞特异性标志物,PCRRFLP检测分析显示,体外诱导分化的细胞的印迹基因IGF2呈双等位基因表达,印迹丢失。结论体外诱导培养可导致胚胎干细胞印迹基因IGF2表达的改变。     

自体脑脊液定向诱导骨髓间充质干细胞分化为神经干细胞

目的 探讨自体脑脊液定向诱导骨髓间充质干细胞分化为神经干细胞的可行性.方法 采用自体脑脊液为诱导剂,体外诱导骨髓源性间充质干细胞.从形态学、免疫组化法、反转录聚合酶链反应(RT-PCR)方法对诱导后细胞进行鉴定.结果 自体脑脊液诱导后的间充质干细胞呈现神经干细胞改变,可分化为神经元、星形胶质细胞和少突胶质细胞,并表现相应的特征结构和生物学特性.结论 白体脑脊液能定向诱导骨髓间充质干细胞向神经样细胞转化.     

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.     

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.