羊乳中类胰岛素生长因子Ⅰ的特性

采用双抗体夹心酶联免疫法研究了温度、p H、紫外线以及金属离子等因素对羊乳中类胰岛素生长因子Ⅰ(insulin-like grouth factor-Ⅰ,IGF-Ⅰ)浓度的影响。研究表明:羊乳中IGF-Ⅰ在20℃时浓度最高,达到(29.91±0.91)ng/m L(P<0.05),在40℃时具有较高的热稳定性;IGF-Ⅰ在p H=4时浓度最高,达到(28.53±1.11)ng/m L(P<0.05),在p H值为6~8时稳定性较高;紫外线照射会造成IGF-Ⅰ的浓度显著降低(P<0.05)。Na^+、Ca^(2+)、Al^(3+)、Zn^(2+)等金属离子对IGF-Ⅰ的浓度具有抑制作用,而Mg^(2+)、Fe^(2+)对IGF-Ⅰ无明显影响,低浓度的Fe^(3+)、Cu^(2+)对IGF-Ⅰ的浓度具有抑制作用,而高浓度的Fe^(3+)、Cu^(2+)对IGF-Ⅰ具有激活作用。通过研究,评估温度、p H、紫外线以及金属离子对羊乳中IGF-Ⅰ浓度的影响,为生产具有更高IGF-Ⅰ浓度的功能活性羊乳产品提供依据和指导。

滋阴泻火方对性早熟大鼠血清类胰岛素样生长因子-Ⅰ水平的影响

目的探讨滋阴泻火方对性早熟模型大鼠血清类胰岛素样生长因子-Ⅰ(IGF-Ⅰ)水平的影响。方法26日龄雌性SD大鼠36只,随机分成6组,即正常对照组、性早熟模型组、亮丙瑞林组及中药大、中、小剂量组。除正常对照组外,其余各组均采用N-甲基-DL-天冬氨酸(NMA)40 mg.kg-1皮下注射建立性早熟模型,其中亮丙瑞林组用亮丙瑞林干预,中药各组用不同剂量的滋阴泻火方干预,观察不同干预措施对性早熟模型大鼠卵巢指数、子宫指数及血清IGF-Ⅰ水平的影响。结果性早熟模型组和中药小剂量组的卵巢指数[分别为(6.37±1.61)×10-4、(5.10±2.59)×10-4]和子宫指数[分别为(8.91±2.32)×10-4、(7.86±1.98)×10-4]均显著高于其他各组(P<0.05);亮丙瑞林组、中药大剂量组和中药中剂量组卵巢指数和子宫指数与正常对照组相比均无统计学差异(P>0.05)。与正常对照组比较,性早熟模型组的血清IGF-Ⅰ水平显著升高[(327.08±46.15)vs(239.40±61.92)m IU.m l-1,P<0.05],而4个干预组均无显著性差异(P>0.05);与性早熟模型组比较,中药大剂量组[(218.83±77.06)m IU.m l-1]和中剂量组[(207.09±53.00)m IU.m l-1]的血清IGF-Ⅰ水平显著降低(P<0.05),中药小剂量组无显著性差异(P>0.05);中药各剂量组与亮丙瑞林组比较无显著性差异(P>0.05)。结论滋阴泻火方大、中剂量能降低性早熟模型大鼠的血清IGF-Ⅰ的水平。

Study on the Cloning, Expression, and Bioactivity of Recombinant Chicken IGF-Ⅰ

The DNA sequence encoding the chicken＇s insulin-like growth factor Ⅰ （IGF-Ⅰ） was amplified with the reverse transcription polymerase chain reaction （RT-PCR）, which was then cloned into vector pMD18-T and sequenced. The sequencing result showed that there was 100% homology among the documented sequences and the sequence reported in this article, which was successfully inserted into the expressing plasmid pRLC and was highly expressed in E.coli. The Tricine-SDS- PAGE result showed that the cloned recombinant protein was expressed in the form of inclusion bodies in the E.coli cell with molecular weight of 7.6 kD and was amount to 23% of the whole protein in the E.coli cell. Western blotting indicated that recombinant protein had the antigenicity of IGF- Ⅰ. The inclusion bodies were subsequently dissolved in 7 M guanidine chloride and renatured with dilution in refolding buffer containing 0.5 M arginine. To obtain pure protein, the renatured chicken IGF- Ⅰ was desalting by Hiprep 26/10 and purified by Hiprep Sephacryl S-200 chromatography. The biological activities of IGF- Ⅰ product were assayed in NIH 3T3 cells and osteoblastic cells of embryonic chicken by using MTT method. The results show that the expressed IGF- Ⅰ can obviously stimulate NIH3T3 cells and osteoblastic cells to proliferate at the concentration ranging from 100, 200, 400 to 800 ng mL^-1, suggesting that the protein has its biological activities.

不同营养方式早产儿血清IGF-I及GH水平的变化研究

目的探讨不同营养方式早产儿血清胰岛素样生长因子(IGF-I)与生长激素(GH)水平的变化及其与生长发育的关系。方法采用放射免疫法测定观察组(42例)与对照组(48例)早产儿出生时及生后第7d、第14d血清IGF-I、GH水平,同时测量两组早产儿相应日龄体质量、身长、头围,计算Rohrer指数(RI),并进行对比分析。结果 (1)两组早产儿生后第14d血清IGF-I水平与脐血及第7d组内比较差异均有统计学意义(P<0.05)。观察组早产儿生后第7d及第14d血清IGF-I水平与对照组相比,差异有统计学意义(P<0.05)。(2)两组早产儿生后第14d血清GH水平差异有统计学意义(P<0.05)。(3)两组早产儿脐血及生后第7d、第14d血清IGF-I水与体质量、RI及GH分别呈正相关,生后第14d血清GH水平与RI呈正相关(P<0.05)。结论 IGF-I及GH在早产儿营养与生长调控的过程中发挥着一定的作用,与早产儿的营养状况密切相关。

胃癌组织中TGF-β_1和TβR_1基因的表达及意义的研究

目的 :观察转化生长因子β1 (TGF-β1 )及其受体 I(TβR1 )基因在人类胃癌组织中的表达及其与胃癌病理生物学行为的关系。方法 :应用抗 TGF-β1 和 TβR1 多克隆抗体对 10 7例胃癌组织中的 TGF-β1 和 97例胃癌组织中的 TβR1 基因表达蛋白进行了 S- P免疫组织化学方法检测。结果 :TGF-β1 在胃癌组织中的阳性表达 (75 % )明显高于癌旁组织 (2 4.4% )及正常组织 (2 9.2 % ) ,差异非常显著 (P <0 .0 1) ;TRβ1 在胃癌组织中阳性表达 (19.6 % )明显低于癌旁组织 (79.6 % )和正常组织 (75 .6 % ) ,差异有显著性 (P <0 .0 5 )。结论 :TGF-β1 和 TβR1 基因的异常表达与胃癌的发展及恶性程度有关。

Protective effect of exogenous IGF-I on the intestinal mucosal barrier in rats with severe acute pancreatitis

Severe acute pancreatitis （SAP） can result in intestinal mucosal barrier （IMB） dysfunction. This study was undertaken to demonstrate the effect of IGF-I on the intestinal mucosal barrier in rats with SAP and its possible mechanisms. Seventy-two male Wistar rats were randomly divided into three groups： a sham operation （SO group, n=24）, a SAP group not treated with IGF-I （SAP group, n=24）, and a SAP group treated with IGF-I （IGF-I group, n=24）. SAP was induced in the rats by injecting 5.0% sodium taurocholate into the biliary-pancreatic duct. The SO rats were given an infusion of normal saline instead. The rats in the IGF-I group underwent the SAP procedure and were given a subcutaneous injection of IGF-I at 30 minutes before the operation and at 3 hours after the operation. Eight rats in each group were sacrificed at 6, 12 and 24 hours after operation. Apoptosis of mucosal cells in the small intestine was determined by TUNEL. The levels of endotoxin and DAO and serum amylase were also measured. Pathologic changes in the small intestine were monitored. Changes of bax and bcl-2 mRNA expression in the small intestine were determined by reverse transcription polymerase chain reaction （RT-PCR）. The levels of serum amylase were lower in the IGF-I group than in the SAP group at all three time points （P〈0.05）. The levels of endotoxin in the IGF-I group were higher than those in the SAP group at 6 hours, but lower in the IGF-I group than in the SAP group at 12 and 24 hours （P〈0.05）. The levels of diamine oxidase were higher in the IGF-I group at 6 hours but lower than those in the SAP group at 12 and 24 hours. The pathological score of the small intestine was lower in the IGF-I group than in the SAP group, and the difference was statistically significant at 12 and 24 hours. The pathologic changes observed under electron microscopy were better in the IGF-I group than those in the SAP group. The apoptosis index of intestinal epithelial cells was significantly decreased in the IGF-I group compared with the SAP group. Compared with the SO group, the mRNA expression levels of bax were increased at each time point in the SAP group, and were significantly decreased in the IGF-I group as compared with the SAP group at each time point （P〈0.05）. The expression levels of bcl-2 were weak and not different between the SO group and the SAP group （P〉0.05）. They were significantly increased in the IGF-I group versus the SO and SAP groups （P〈0.05）. The ratio of bax and bcl-2 mRNA expression levels at each time point in the SAP group were significantly higher than those in the SO group, but they were obviously decreased in the IGF-I group. Exogenous IGF-I seems to protect mucosal cells in the small intestine against SAP-induced apoptosis and could alleviate SAP-induced injury of the intestinal mucosa. The underlying mechanisms include enhanced mRNA expression of bcl-2 and inhibition of bax mRNA expression.

阻塞性腺样体和扁桃体肥大与胰岛素样生长因子系统

阻塞性腺样体和扁桃体肥大可能引起儿童生长发育异常,其病理生理机制尚不明确。本文就血清胰岛素样生长因子-1(insulin-likegrowthfactorI,IGF-1)/胰岛素样生长因子结合蛋白-3(insulin-likegrowthfactor-bindingprotein3,IGFBP-3)概况及其在阻塞性腺样体和扁桃体肥大患儿生长激素分泌异常诊断和疗效判断方面的意义进行综述。

IGF-Ⅰ基因多态性与大于胎龄儿及脐血IGF-Ⅰ血清水平关系分析

目的探讨IGF-Ⅰ基因多态性与大于胎龄儿及脐血IGF-Ⅰ血清水平的关系,为降低大于胎龄儿的发生率提供理论依据。方法采用病例对照的研究方法,在南京地区收集大于胎龄儿（LGA）和适于胎龄儿（AGA）各96名,应用聚合酶链反应—限制性片段长度多态性方法（PCR-RFLP）检测IGF-Ⅰrs6214及rs35767的多态性,采用单因素Logistic回归分析计算LGA的相对危险度,比较2组间不同基因型出生时体格指标和脐血IGF-Ⅰ水平的差异。结果在LGA组和AGA组中,IGF-Ⅰrs35767 TT基因型可能会降低大于胎龄儿的风险（OR=0.235,95%CI=0.081~0.682）,携带TT基因型个体的体重、头围和孕周均低于CC及CT基因型携带者;IGF-Ⅰrs6214 AG/GG基因型可能会增加大于胎龄儿的风险（OR=2.117,95%CI=1.151~3.894）。未发现2个多态性位点的改变与脐血IGF-Ⅰ血清水平相关。结论 IGF-Ⅰrs6214和rs35767多态性均与大于胎龄儿的发生相关。