大鼠胰岛分离条件的优化

目的:优化大鼠胰岛分离纯化的条件,为胰岛移植实验奠定基础。方法:通过胆总管灌注胶原酶P来消化大鼠胰腺,分离胰岛,采用不连续密度梯度Ficoll离心法纯化胰岛,观察胶原酶浓度、消化时间以及大鼠体重对胰岛分离结果的影响。双硫腙染色鉴定胰岛,丫啶橙/碘丙啶染色鉴定胰岛细胞活率,糖刺激胰岛素释放试验评价胰岛功能。结果:胶原酶浓度、消化时间以及大鼠体重对胰岛分离结果有重要影响。1mg/ml胶原酶P在37℃静止消化45分钟条件下,胰岛分离效果最佳,效果较其他酶浓度和消化时间条件下好(P＜0．05)。体重350g的大鼠的胰岛收获量778．33±80．21IEQ/胰腺,而体重250g的大鼠的胰岛收获量655．00±56．56 IEQ/胰腺(P＜0．05)。优化条件下分离的胰岛其纯度＞90%,胰岛细胞活率＞90%,低糖(2．8mmol/L)、高糖(16．7mmol/L)刺激胰岛素释放分别为(5．40±1．75)mIU/L/30IEQ,(12．27±2．55)mIU/L/30IEQ(P＜0．05),刺激指数为2．33±0．29。结论:胶原酶浓度、消化时间以及大鼠体重影响胰岛分离结果,优化分离条件可改善大鼠胰岛分离结果。     

实验动物胰岛细胞的分离纯化

胰岛移植作为治疗1型糖尿病的有效方法,临床应用前景较好。但是,由于在胰岛移植手术中,有功能的胰岛细胞数量较少,而严重影响其治疗效果。因此,如何提高胰岛分离纯化效果,获取尽可能多的高质量的胰岛,成为胰岛移植手术成败的关键。本文仅就在采用实验动物分离和纯化胰岛方面的实验经验作以简要介绍。     

一种高效、快捷、经济的小鼠胰岛细胞分离纯化方法

采用改良的胶原酶P胆总管内逆行灌注膨胀胰腺的分离方法,比较Ficoll-400不连续密度梯度离心法和人工挑取法两种纯化胰岛的方法,用双硫腙(DTZ)对胰岛细胞团进行特异性染色计算胰岛产量及纯度,用台盼蓝染色判定胰岛细胞活性,使用间接免疫荧光法检测体外培养7 d后胰岛的功能.采用人工挑取法平均每只小鼠可获取的胰岛细胞团(245±35.6个)明显高于密度梯度离心法(120±26.3个)(n=5,P<0.05),两种方法分离纯化的胰岛活力均大于98%;但人工挑取法获得胰岛细胞团的纯度(100%)要高于密度梯度离心法(90%);纯化胰岛所用时间,采用人工挑取法(22±4 min)也少于密度梯度离心法(31±3 min).间接免疫荧光染色检测体外培养7 d后的胰岛细胞团,两种方法分离纯化的胰岛细胞团均具有良好的功能.胶原酶P胆总管内灌注消化分离法联合人工挑取纯化胰岛细胞团的方法,是一种高效、快捷、经济的小鼠胰岛细胞团分离纯化方法.     

一种高效经济的小鼠胰岛细胞分离纯化新技术

目的:建立一种经济高效的小鼠胰岛细胞分离纯化方法,为进行NOD小鼠的胰岛移植提供实验条件.方法:将5-7周龄、体重20～25 g的雄,陛昆明小鼠的胆总管结扎,并逆行Hank's液和胶原酶P灌注和分离消化,依次加入84%、67%、50%浓度的Histopaque介质后进行不连续密度梯度离心纯化胰岛细胞.双硫腙(dithizon,DTZ)和台盼兰染色分别鉴定胰岛细胞.用含5.6mmol/L葡萄糖DMEM培养液体外培养胰岛细胞,培养后的第3、5、7、9、11天取细胞上清检测胰岛素水平,并用16.7mmol/L的高浓度葡萄糖进行刺激,检测胰岛素水平确定胰岛细胞功能.结果:每个胰腺的胰岛细胞收获量在1200±124个,且纯度和活性均大于90%;体外培养9天内胰岛细胞基础胰岛素分泌水平无显著差异,至第11天时则明显减少(P＜0.05);应用16.7mmol/L葡萄糖刺激后,第5、7、9、11天的胰岛素分泌水平较第3天的明显减少(P＜0.05),然而在第7天、9天、11天时的胰岛素水平较第5天时显著降低.结论:胆总管逆行注射Hank's液和胶原酶P消化消化和不连续密度梯度Histopaque纯化的方法可以获得大量状态良好的胰岛,且胰岛细胞数量多,分泌状态良好.本分离方法是一种经济高效的胰岛细胞分离方法,同时离体后于5.6mmol/L葡萄糖DMEM培养第3天胰岛细胞胰岛素储备功能最佳,为移植研究的最佳状态.     

复方泛影葡胺速率区带密度梯度离心法纯化衣原体

目的利用速率区带密度梯度离心法建立纯化高纯度、高感染力衣原体的方法。方法采用HeLa229细胞扩增衣原体,制作含有大量衣原体的细胞裂解液,以国产复方泛影葡胺作为介质,利用速率区带密度梯度离心法纯化衣原体,负染纯化产物后使用透射电镜观察形态,并将纯化产物感染HeLa229细胞,测定纯化产物的感染力。结果在透射电镜下观察,证实纯化产物为直径300 nm左右的高纯度原体。纯化产物的感染力为8.62×10~8 IFU/mL,证实该纯化产物具有高感染力。结论通过复方泛影葡胺速率区带密度梯度离心法,可获得高纯度、高感染力的衣原体,为开展衣原体感染机制、免疫反应等研究提供了有效而可靠的保证。     

重组人胰岛新生相关蛋白的高水平表达与纯化

通过RT-PCR体外扩增目的基因胰岛新生相关蛋白(islet neogenesis associated protein,INGAP),并将其克隆入原核表达载体pET22b(+),在大肠杆菌BL21(DE3)中诱导表达.表达的目标蛋白主要以包涵体形式存在,洗涤杂蛋白后用尿素溶解,经Heparin Agrose亲合柱层析分离后,再用Superdex75凝胶过滤层析进一步纯化.纯化后的INGAP皮下注射免疫家兔,制备兔抗INGAP血清,采用免疫双扩、ELISA评价INGAP的免疫活性.结果显示INGAP表达量高达菌体总蛋白的40%左右,经HPLC测定,分离纯化后的目标蛋白纯度达到98.81%,且具有良好的免疫原性.     

大鼠精原干细胞的高效分离和纯化方法

精原干细胞是精子发生的基础,是永久分化成精子的克隆源,它既可以自我更新维持体内干细胞的数量,又可以增殖分化形成各阶段的生精细胞直至成熟精子。本文以22～25日龄Wistar-Iamichi大鼠为研究对象,利用两步酶消化法分离得到睾丸曲细精管细胞悬液,根据精原干细胞与曲细精管细胞悬液中体细胞(支持细胞及少量的管周细胞)及各级分化的生精细胞贴壁能力及对细胞外基质粘附力的不同,将大鼠精原干细胞进行纯化。经纯化后,5只大鼠的睾丸可以得到约3×10~5个精原干细胞,该精原干细胞在体外培养可形成克隆,并且该克隆可表达精原干细胞特异的标记基因GFRα1和CDH1。本文所介绍的高效分离和纯化大鼠精原干细胞的方法,操作简便,且得到的精原干细胞具有很高的活力和增殖能力,该方法为今后大鼠精原干细胞的长期培养及操作研究奠定了基础。     

重组人胰岛新生相关蛋白的表达、纯化及免疫活性研究

摘要 目的：对胰岛新生相关蛋白（Islet neogenesis associated protein ,INGAP）进行表达、纯化,并检测其免疫活性。方法： INGAP基因片段插入表达载体pET22b(+),在E.coli BL21(DE3)中表达。包涵体经洗涤并用8M尿素溶解,Heparin Agrose亲合柱层析为第一步纯化,Superdex75凝胶过滤层析作为第二步精细纯化,HPLC测定INGAP蛋白的浓度,将纯化的INGAP蛋白经注射途径免疫家兔,制备兔抗INGAP血清,采用免疫双扩、ELISA及Western Blot分析INGAP的免疫活性。结果INGAP以包涵体形式表达,表达产量高达总菌体蛋白的40%左右,经Heparin Agrose亲合柱层析和凝胶过滤层析二步组合纯化目的蛋白,经HPLC测定目的蛋白的最终纯度为98.81%,表达及纯化的INGAP具有良好的免疫活性。     

木聚糖酶分离纯化技术

木聚糖酶应用广泛,其分离纯化是进行酶学性质研究、分子研究的前提条件,是成功确定氨基酸序列和三维结构的基础。综述微生物木聚糖酶分离纯化的方法,分析了常用方法在其分离纯化中的优缺点;强调了特异性分离纯化技术是高效的分离纯化方法;并对其它方法进行了概括。     

密度梯度离心分离大鼠卵巢卵泡膜细胞

探讨用密度梯度离心法快速、有效地分离大鼠卵泡膜细胞.选取23～25 d雌性大鼠卵巢,用Percoll密度梯度离心法将卵泡膜细胞分离纯化,3β-羟基类固醇脱氢酶(3β-hydroxysteroid dehydrogenase,3β-HSD)组织化学染色用于卵泡膜细胞纯度检测.分别用0.1 U/mL和1.0 U/mL卵泡刺激素(Follicle-stimulating hormone,FSH)及黄体生成素(luteinizing hormone,LH)处理细胞,无血清培养48 h后,酶联免疫法检测培养液中雄烯二酮和雌二醇的水平.分离所得细胞中,3β-HSD染色阳性细胞与总细胞数之比大于90％; LH组的雄烯二酮水平显著高于对照组和FSH组(P＜0.05),LH组中1.0 U/mL组的雄烯二酮水平又高于0.1 U/mL组.各组均未检测到雌二醇及孕酮.3β-HSD组织化学染色可快速有效地检验所分离的卵泡膜细胞的纯度,分离所得的卵泡膜细胞可对LH产生反应,且其中几乎没有混杂颗粒细胞.     

狂犬病疫苗蔗糖密度梯度离心纯化工艺开发

目的:开发冻干人用狂犬病疫苗(鸡胚成纤维细胞)的连续流蔗糖密度梯度离心纯化工艺。方法:分别比较两种不同初始蔗糖浓度和不同上样速度对纯化效果的影响,初步确定纯化工艺;通过多批次实验确定样品收集范围;比较不同浓缩倍数条件下杂质去除和抗原回收情况,确定合适的收获液浓缩比例;比较不同批次样品纯化后的杂质去除率和重复性,判定本纯化工艺的稳定性。结果:选取60%作为初始蔗糖浓度,在上样速度为150～200ml/min时,可以有效地对10倍浓缩的病毒收获液进行纯化;卵清蛋白、牛血清白蛋白和庆大霉素去除率分别达到99%,95%和95%,且工艺具有极好的稳定性。结论:开发的连续流蔗糖密度梯度离心技术可以作为冻干人用狂犬病疫苗(鸡胚成纤维细胞)的产业化纯化工艺。     

Optimizing Conditions for Rat Pancreatic Islets Isolation

Many procedures have been described for rat pancreatic islet isolation. Several factors contribute to the pancreatic islet isolation outcome. One of the main problems in islet isolation procedure is the formation of a viscouse, gellike structure during collagenase digestion which entraps the free islets and decrease islet yield after density gradient purification. This issue has not been addressed in most techniques described for rat islet isolation. We examined effect of various factors to eliminate formation of gellike material and improve the islets yields. Islet isolation was performed on 26 adult male Wistar Albino rats weighing between 280 and 350 g. We have observed that several factors affect pancreatic islet isolation. Optimum Collagenase enzyme concentration, maintaining pH range between 7.7 and 7.9 in digestion solution, incubation temperature at 38±1 °C and addition of Calcium ion decreased the formation of gellike materials and increased islet yield. Addition of Glycerol as a gelatin solvent has also been helpful in the reduction or complete elimination of gellike material. Precise optimization of rat islet isolation procedure is useful to improve the islet yield in islet transplantation studies.     

Purification of Poly-beta-Hydroxybutyrate by Density Gradient Centrifugation in Sodium Bromide

Fractionation of fully sporulated cultures of Bacillus thuringiensis by density gradient centrifugation in NaBr produced two bands which were identified as poly-beta-hydroxybutyrate. This technique generated high yields of membrane-bound and unbound granules of exceptional purity and degree of polymerization.     

Purification of Large Quantities of Influenza Virus by Density Gradient Centrifugation

New zonal centrifuges can conveniently process as much as five orders of magnitude (10(5)) greater sample volumes than conventional swinging-bucket rotors. The continuous-sample-flow-with-banding versions may be used in series with ancillary purification procedures. Here we have studied the combined process: absorption and elution of influenza virus with barium sulfate followed by concentration and isopycnic banding of the virus in a buffered sucrose gradient. Kilogram quantities of impurity have been rapidly separated from grams of purified virus, which have been conveniently concentrated several hundred-fold by the purification process. Experimental vaccines made by these procedures are being evaluated.     

Purification of Large Quantities of Coxiella burnetii Rickettsia by Density Gradient Zonal Centrifugation

The purification of large quantities of inactivated, phase II Coxiella burnetii by isopycnic zonal centrifugation for use as diagnostic antigen and as a vaccine is described. The fractionation of egg yolk sac-derived C. burnetii vaccine resulted in the separation of two distinct populations of organisms, each devoid of microscopically and serologically recognizable components of egg yolk sac. One population of organisms, characterized by an equilibrium density of 1.240, was rod shaped (1.0 by 0.5 μmole) with a thick, densely strained wall and prominent central body. The second population, with an equilibrium density of 1.280, had a coccobacillary shape (approximately 1 μmole in diameter), granular, sometimes fibrillar cytoplasm, thin cellular walls, and lacked a prominent nucleoid.     

Large-Scale Purification of Ribonucleic Acid Tumor Viruses by Use of Continuous-Flow Density Gradient Centrifugation

This report describes a 200- to 300-fold increase in the quantity of ribonucleic acud tumor virus particles previously isolated at one time by zonal centrifugation.     

Autoimmunity against INS-IGF2 Protein Expressed in Human Pancreatic Islets

Insulin is a major autoantigen in islet autoimmunity and progression to type 1 diabetes. It has been suggested that the insulin B-chain may be critical to insulin autoimmunity in type 1 diabetes. INS-IGF2 consists of the preproinsulin signal peptide, the insulin B-chain, and eight amino acids of the C-peptide in addition to 138 amino acids from the IGF2 gene. We aimed to determine the expression of INS-IGF2 in human pancreatic islets and autoantibodies in newly diagnosed children with type 1 diabetes and controls. INS-IGF2, expressed primarily in beta cells, showed higher levels of expression in islets from normal compared with donors with either type 2 diabetes (p = 0.006) or high HbA1c levels (p < 0.001). INS-IGF2 autoantibody levels were increased in newly diagnosed patients with type 1 diabetes (n = 304) compared with healthy controls (n = 355; p < 0.001). Displacement with cold insulin and INS-IGF2 revealed that more patients than controls had doubly reactive insulin-INS-IGF2 autoantibodies. These data suggest that INS-IGF2, which contains the preproinsulin signal peptide, the B-chain, and eight amino acids of the C-peptide may be an autoantigen in type 1 diabetes. INS-IGF2 and insulin may share autoantibody-binding sites, thus complicating the notion that insulin is the primary autoantigen in type 1 diabetes.     

Purification of Poly-β-Hydroxybutyrate by Density Gradient Centrifugation in Sodium Bromide

Fractionation of fully sporulated cultures of Bacillus thuringiensis by density gradient centrifugation in NaBr produced two bands which were identified as poly-β-hydroxybutyrate. This technique generated high yields of membrane-bound and unbound granules of exceptional purity and degree of polymerization.