双嘧达莫对体外培养神经干细胞增殖的影响

目的研究双嘧达莫(dipyridamole)对体外培养神经干细胞的促增殖作用.方法取新生小鼠大脑进行神经干细胞原代培养,通过神经球生成的观察、特异性蛋白质免疫细胞化学染色和BrdU标记鉴定并判断其增殖能力;双嘧达莫按0.1,0.5,2.5 μmol·L-13个浓度加入神经干细胞培养基中,同时设立溶媒对照组和阳性对照组,通过观察神经球形态、神经球生成数目及MTT法定量比较,分析不同浓度双嘧达莫对神经干细胞分裂增殖的影响.结果在培养物中有大量神经球生成,神经干细胞的特异性蛋白质免疫细胞化学染色呈阳性,BrdU标记亦呈阳性反应,表明所培养的细胞为神经干细胞,具有增殖能力.双嘧达莫中、高浓度组神经球数目、MTT比色结果明显高于溶媒对照组.结论双嘧达莫具有促进神经干细胞增殖的作用.     

骨骼肌提取液促进体外培养神经干细胞增殖作用研究

目的寻找促神经干细胞分裂增殖物质,为神经系统发育研究和神经系统疾病的治疗研究提供新的依据。方法用硫酸铵盐析及超滤离心法分离骨骼肌蛋白质,体外培养新生小鼠神经干细胞,通过神经球生成的观察、特异性蛋白质免疫细胞化学染色和MTT比色检测法鉴定神经干细胞并判断其增殖能力。结果在培养物中有大量神经球生成,且与对照组差异有显著性(P<0.01),神经干细胞的特异性蛋白质(Nestin)免疫细胞化学染色呈阳性。结论骨骼肌提取液可促进体外培养神经干细胞增殖分裂,且呈一定量效关系,其有效成分为分子量≤100 ku的蛋白质分子。     

黄芪甲苷对体外神经干细胞增殖作用影响的研究

目的探讨黄芪甲苷(astragaloside,AS)对神经干细胞增殖的影响。方法体外培养大鼠胎鼠神经干细胞,Nestin免疫化学染色鉴定NSCs,BrdU标记鉴定NSCs增殖。BrdU标记免疫细胞化学染色检测神经干细胞增殖能力。实时定量PCR技术探讨黄芪甲苷促进NSCs增殖的作用机制。结果Nestin鉴定为阳性,Brdu标记亦呈阳性;BrdU标记结果表明,黄芪甲苷高、中、低剂量组NSCs的增殖率明显提高(P<0.05,P<0.01)。实时定量PCR结果表明在诱导NSCs增殖过程中,黄芪甲苷高剂量组Hes5基因表达增加(P<0.05)。结论黄芪甲苷对NSCs增殖具有明显的诱导作用,其可能通过上调与细胞增殖相关基因Hes1、Hes5、cyclinD1表达而起作用,但也可能调节与其它增殖通路有关。     

托吡酯促进体外培养神经干细胞增殖的实验研究

目的:研究托吡酯对体外培养神经干细胞的促增殖作用。方法:取新生小鼠大脑进行神经干细胞原代培养,托吡酯按0.4、2、10μmol.L-13个量级(或3种浓度)加入神经干细胞培养基中,同时设立溶媒对照组和阳性对照组,通过神经球生成数目及MTT法定量比较,分析不同浓度托吡酯对神经干细胞分裂增殖的影响。结果:2、10μmol.L-1托吡酯组神经球数目分别为20.67±4.04和49.68±3.79;MTT比色结果分别为0.3546±0.0705和0.5018±0.0369,明显高于溶媒对照组(7.34±2.31、0.2880±0.0093,P<0.01)。结论:托吡酯具有促进神经干细胞增殖的作用。     

甲氨蝶呤对体外培养神经干细胞的毒性作用

目的:观察甲氨蝶呤(MTX)对体外培养的神经干细胞(NSC)毒性作用的特点,并初步探讨其毒性机制.方法:体外培养胎鼠大脑皮质NSCs,采用Nestin免疫荧光法进行鉴定;光镜下观察MTX干预后NSC形态变化;采用5-溴脱氧尿苷(BrdU)掺入法和Nestin/BrdU免疫组化双标记检测MTX对NSCs增殖的影响;流式细胞术分析细胞周期变化;高压液相法检测细胞内同型半胱氨酸(Hcy)的浓度.结果:400μg/L MTX可引起明显的细胞形态改变;免疫荧光双标记结果显示,与对照组相比,MTX干预组可明显抑制NSCs增殖(JP<0.05);MTX干预48 h后,细胞停留在G1期的比例比空白对照组明显增加;MTX还可引起细胞内Hcy浓度升高.结论:MTX可能通过改变细胞周期和升高细胞内Hcy浓度而对体外培养NSCs产生明显的毒性损伤作用.     

EGB对大鼠神经干细胞分化为星形胶质样细胞的影响

目的：观察银杏叶提取物（EGB）对大鼠海马神经干细胞（NSCs）增殖及分化为星形胶质样细胞的影响。方法：取新生24h内的Wistar大鼠海马组织的细胞进行体外培养，1周后将其接种在培养板中．观察不同浓度的EGB对细胞的生长作用．并检测胶质原纤维酸性蛋白（GFAP）的表达。结果：各实验组NSCs的生长明显好于对照组．免疫细胞化学显示：同一时间内，诱导NSCs分化为星形胶质样细胞的百分率增高；同一浓度的EGB，诱导神经干细胞分化为星形胶质样细胞的百分率随着时间的延长呈上升的趋势。结论：EGB能促进神经干细胞的存活、增殖及向星型胶质样细胞的方向分化。     

胎鼠神经干细胞培养方法的建立及药物对干细胞增殖的影响

目的建立神经干细胞培养模型，观察药物对其增殖能力的影响。方法建立大鼠胎脑神经干细胞的培养方法，并用MTT法和3H-胸腺嘧啶核苷参入法观察黄皮酰胺、丹酚酸A及人参皂苷Rg1等对第2代神经球细胞状态的影响。结果免疫细胞化学结果显示，培养的神经细胞具备干细胞的基本特性；MTT和液闪结果则表明，上述3种药物可不同程度地影响神经干细胞的存活率和/或增殖活性。结论本实验所建立的胚胎大鼠神经干细胞培养模型可以观察到一些有脑保护作用的药物对干细胞存活和增殖有一定影响。     

骨髓基质细胞和神经干细胞体外共培养的实验研究

目的:研究神经干细胞(NSCs)和骨髓基质细胞(MSCs)共培养时对各自分化的影响。方法:将2种细胞按接种数目分为5组,A组为NSCs∶MSCs=105∶0;B组为NSCs∶MSCs=105∶104;C组为NSCs∶MSCs=105∶105;D组为NSCs∶MSCs=104∶105;E组为NSCs∶MSCs=0∶105。培养7d后分别进行5-溴-2-脱氧尿嘧啶(BrdU)和神经元特异性烯醇化酶(NSE)、胶质细胞纤维酸性蛋白(GFAP)、微管相关蛋白2(MAP2)、半乳糖神经酰胺(GalC)免疫细胞化学双染色。结果:随着MSCs比例的提高,各组BrdU和NSE或MAP2的双阳性细胞表达差异有统计学意义(P<0.05),且B、C及D组分别与A组比较差异亦有统计学意义(均P<0.01);随NSCs比例的增高,B、C、D组NSE、MAP2和GFAP双阳性MSCs表达逐渐增高(均P<0.01)。结论:MSCs可以促进NSCs分化为神经元,而且在NSCs诱导下部分MSCs可以转化为神经元和星形细胞。     

成年大鼠嗅球神经干细胞的培养和鉴定

目的建立成年大鼠嗅球神经干细胞分离培养和鉴定方法,探索新的成年神经干细胞种子来源。方法用无血清方法分离培养成年大鼠嗅球来源的神经干细胞;用克隆培养、BrdU整合的方法检验培养细胞的干细胞特性;用免疫荧光细胞化学的方法检测BrdU、神经干细胞标记物Nestin和SOX2,分化的细胞标记物Tuj1、GFAP、NG2的表达。结果从成年大鼠嗅球能够分离、培养出具有自我更新、增殖的神经球,构成神经球的细胞呈Nestin和SOX2阳性,它们分化后产生Tuj1阳性的神经元、GFAP阳性的星形胶质细胞、NG2阳性的少突胶质细胞。结论成年大鼠嗅球存在神经干细胞,能够在体外进行培养、增殖、分化,是神经干细胞的新的种子来源。     

磁标记神经干细胞移植治疗脑梗死大鼠MRI示踪及形态学研究

目的:利用磁共振成像(MRI)技术追踪移植的超顺磁性氧化铁标记神经干细胞(NSCs),无创、动态地监测NSCs在活体脑内的存活和迁移。方法:大鼠32只制备右侧大脑中动脉瘤局灶脑缺血/再灌注(MCAO)模型,BrdU标记NSCs,立体定向磁标记NSCs脑内移植,MRI下活体动态追踪脑内移植的磁标记NSCs,实验动物于磁标记NSCs脑内移植第1、5和14天达到观察时相点后,取脑组织做石蜡切片及HE染色。结果:24只大鼠出现明显的神经功能缺失症状。MRI追踪示:磁标记NSCs脑内移植1d后,针道和侧脑室部位有低信号物质存在;磁标记NSCs脑内移植5d后,低信号物质沿胼胝体腹侧迁移;磁标记NSCs脑内移植2周,右侧(病灶侧)侧脑室部位低信号物质向缺血区迁移,其前端已达到缺血区的边缘。脑组织病理学检测:BrdU阳性磁标记NSCs沿胼胝体腹侧向缺血/再灌注区迁移。随着脑内磁标记移植时间的推移,侧脑室区的NSCs向缺血/再灌注区迁移数量逐渐增加。结论:超顺磁性氧化铁颗粒和BrdU双标记的神经干细胞移植至脑梗死大鼠脑内后可迁移到病灶区;MRI成像能够在活体内连续示踪观察神经干细胞的迁移及分布情况。     

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.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.