Mobility assays confirm the broad host-range activity of the Minos transposable element and validate new transformation tools

Fast and reliable methods for assessing the mobility of the transposable element Minos have been developed. These methods are based on the detection of excision and insertion of Minos transposons from and into plasmids which are co-introduced into cells. Excision is detected by polymerase chain reaction (PCR) with appropriate primers. Transposition is assayed by marker rescue in Escherichia coli, using a transposon plasmid that carries a tetracycline resistance gene and a target plasmid carrying a gene that can be selected against in E. coli. Using both assays, Minos was shown to transpose in Drosophila melanogaster cells and embryos, and in cultured cells of a mosquito, Aedes aegypti, and a lepidopteran, Spodoptera frugiperda. In all cases, mobility was dependent on the presence of exogenously supplied transposase, and both excision and transposition were precise. The results indicate that Minos can transpose in heterologous insect species with comparable efficiencies and therefore has the potential to be used as a transgenesis vector for diverse species.     

Green fluorescent protein as a genetic marker in transgenic Aedes aegypti

We report here the use of the enhanced green fluorescent protein (EGFP) from the jellyfish, Aequorea victoria, as a genetic marker for the genetic transformation of mosquitoes. The EGFP gene, under the control of the actin5C promoter of Drosophila melanogaster was inserted into the Hermes transposable element. Preblastoderm embryos of a wild-type strain of the yellow fever mosquito, Aedes aegypti, were microinjected with this plasmid, together with a helper plasmid containing the Hermes transposase placed under the control of the D. melanogaster hsp70 promoter. Somatic EGFP expression was observed during early instars in approximately one-half of all G0 individuals. Two G1 individuals arising from a G0 female displayed high levels of EGFP gene expression during all stages of development. EGFP was transmitted in a Mendelian fashion to the G2 and G3 generations and molecular analysis confirmed the presence of the Hermes[actin5C:EGFP] gene in these insects. These results clearly demonstrate that EGFP can be used as an effective genetic marker in wild-type Ae. aegypti and most likely in other mosquito species as well.     

Management of benign oesophageal strictures in children

Managing oesophageal strictures, whether benign or malignant has always been a challenging task for ENT Surgeons, Endoscopists, Cardio-thoracic surgeons and Gastro-enterologists. Although various newer technological developments have helped in better management of malignant strictures, it is the benign strictures that are still being managed by conventional means with gum-elastic bougies and other dilatation techniques. Children are not immune to benign strictures, rather corrosive strictures, congenital webs and membranes etc. are much more common in the paediatric age group. We present the technical details and our experience in managing benign oesophageal strictures in five children by endoscopic balloon dilatation.     

矮小身材儿童全血锌、铜、铁、钙、镁含量分析

目的:观察矮小身材儿童全血锌、铜、铁、钙、镁含量的变化并进行分析。方法:采用火焰原子吸收法检测88例矮小儿童的全血锌、铜、铁、钙、镁含量。结果:矮小儿童的低血锌、低血铜、低血铁、低血钙发生率分别为55.68%、28.41%、51.14%和71.59%,血镁均在正常范围内,未见5种金属元素升高者。低血锌、低血铜、低血铁发生率分别在家族性矮小、GHD、体质性等原因引起的矮小儿中最高,而低血钙率在3组矮小儿间无明显差别。结论:矮小身材儿童体内存在不同程度的锌、铜、铁、钙缺乏,且低血锌、低血铜、低血铁发生率在不同病因中存在差异,故对矮小儿童要注意适当补充锌、铜、铁、钙等金属元素。     

哺乳期农村乳母乳汁无机元素含量的变化

目的了解哺乳期人乳无机元素含量的变化及其与乳母膳食的关联。方法采用横断面调查方法,收集55名陕西省澄城县农村健康乳母清晨乳样,利用原子吸收分光光度法测定乳汁钙、镁、铁、锰、锌和铜的浓度。采用24小时回顾法进行连续3天膳食调查,计算膳食营养素的摄入量。结果农村乳母乳汁中镁、锌、铜浓度随哺乳期延长明显降低,铁浓度随哺乳期延长而上升。乳母膳食钙摄入量约为钙膳食参考摄入量(DRI)1/3,膳食无机元素的摄入量与人乳相应元素之间无明显相关性。多因素分析表明,乳汁中钙与镁、铁与铜、锰与锌均呈正相关,钙分别与乳脂、铁、锌呈负相关。结论随哺乳期时间延长,成熟乳中镁、锌、铜浓度降低而铁浓度增加,乳母膳食钙的摄入严重不足,乳汁各元素与膳食相应元素之间无关联。     

黄豆油中8种金属元素的测定与分析

采用微量注射进样火焰原子吸收法测定了黄豆油中8种金属元素的含量,其中钙、镁、铁、铜、锌、锰、钾、钠的含量分别为151.50,56.80,6.39,1.24,18.82,1.31,8.63,2.72μg/g。同时分析了元素含量之间的比例关系。     

剖宫产中催产素的应用研究

近年来随着剖宫产数量的增加，随之出现的并发症也越来越多，其中最常见的为术中宫缩乏力引起的出血。本文首先介绍了催产素在产程中的正确使用方式，然后讨论了将催产素在剖宫产术前静滴，对规律宫缩后行剖宫手术的40例产妇进行了统计，结果表明取得了良好效果。     

维药刺山柑叶子中微量元素和氨基酸成分的研究

目的分析测定维药刺山柑叶子中的矿质元素和氨基酸成分。方法采用火焰分光光度法和原子吸收分光光度法分析测定了刺山柑叶子13种矿质元素,采用日立835-50型氨基酸自动分析仪测定了叶子中的氨基酸成分。结果刺山柑叶子富含K,Ca,Mg,Na 4种常量元素和Fe,Zn,Mn,Cu,Ni,Co 6种微量元素,重金属元素Pb,Cr的含量均低于国家标准。刺山柑叶子中富含18种氨基酸成分,其中包括7种人体必需氨基酸,总氨基酸含量为17.88%。结论维药刺山柑叶子富含矿质元素和氨基酸,具有潜在的开发价值。     

利用CT扫描及CAD技术建立肺三维有限元模型

目的探讨建立肺有限元模型的方法,以期应用于临床实验研究。方法通过CT扫描、Unigraph-icsV18.0进行影像边界记录、定标等方法,按照点、线、面、体的顺序重建三维结构,采用CAD数据处理技术,输入相关的材料特性,构建肺三维有限元模型。并通过有限元分析验证重建模型的有效性。结果采用Uni-graphicsV18.0建立肺的实体模型并划分单元,分析在生理载荷下肺不同组成部分的应力分布。结论该研究为肺有限元模型的建立提供了一种简便、准确的方法,为分析和研究各种情况下肺生物力学表现和为建立肺癌的运动模型创造了条件。     

颈椎三维有限元模型的建立与应用

目的建立颈椎的三维有限元模型(C4/5/6),以用于临床试验研究。方法根据条件选取健康成年男性志愿者,通过CT扫描,得到颈椎的连续断层数据图片,通过医学三维重建软件Materialise Mimics、作图软件Uni-graphics NX、有限元分析软件ANSYS 8.1构建出颈椎的三维有限元模型,进行边界设定,在模型上加载45N的预载荷,再加以2.0 N.M的纯力矩模拟脊柱的前屈、后伸、左右侧曲、旋转的生理活动,观察正常FSU(C4/5)的运动与受力,并与体外实物生物力学实验结果比较。结果C4/5三维有限元模型的运动范围与体外实体实验结果在统计学上没有显著差异(P<0.01)。结论建立的颈椎有限元模型可以模拟颈椎的生物力学特性。