Evidence for the interaction between antacid and gastric mucosa using an "artificial stomach" model including gastric mucosa.

In light of evidence that certain aluminum-based antacids adhere to the gastric mucosa, we modified our previously described "artificial stomach" (AS) model by including a piece of hog stomach and compared the antacid activity of six aluminum-containing antacid products in the model with and without gastric mucosa. The activity of three of these, Maalox, Riopan and Supralox, was not significantly different in the two systems. In contrast, the activity of the other three, Aludrox, Phosphalugel and Simeco, was significantly greater with mucosa. Antacid activity of one product from each set (Supralox, Phosphalugel) was evaluated in two in vivo methods in human volunteers. For both antacids, results in vivo were similar to those obtained with the AS-containing mucosa. Without mucosa, in vivo and in vitro results were dissimilar for Phosphalugel, thus validating the modified AS. The difference between the two sets of antacids can be explained by 1) the fact that the Al:Mg ratio in the set affected by mucosa is greater than that of unaffected antacids, and 2) a weaker antacid load than in unaffected Supralox. We suggest that in an acid milieu, aluminum ions in antacids like Aludrox, Phosphalugel and Simeco are bound to sialic acid residues in mucus glycoproteins, thus retarding the transit of these antacids through both the AS and the real stomach and prolonging their activity in both situations. When the Al:Mg ratio is low or when the amount of antacid salts is large, aluminum ions tend to be buried in complexes, giving them less chance to interact with gastric mucus, so they transit the stomach more quickly.     

Molecular genetic characterization of XRCC4 function

XRCC4 is a generally expressed protein of 334 amino acids that is involved in the repair of DNA double-strand breaks and in V(D)J recombination, but its function is unknown. In this study, we have used a mutational approach and the yeast two-hybrid method to perform an initial characterization of this protein. We show that the XRCC4 protein is located in the nucleus. We also demonstrate that several potential phosphorylation sites are not required for XRCC4 function in a transient V(D)J recombination assay. In addition, we show that XRCC4 forms a homodimer in vivo with the homodimerization domain being located within amino acids 115-204. Finally, we define a core domain of XRCC4 that functions in V(D)J recombination and comprises amino acids 18-204. Potential functions of XRCC4 are discussed.      

扫描电镜图像处理系统及其在细胞超微结构定量计算中的应用

本文介绍一种具有较高性能价格比的生物医学电镜图像处理系统,该系统以IBM PC/XT,AT或386计算机为主机,图像接口板直接插入机内扩展槽。应用软件可对生物医学图像作图像处理和定量计算。作者通过对人膈腹膜超微结构进行定量分析,为腹水的治疗和腹膜透析(CAPD)等临床医学研究,提供了形态学定量资料。     

乙醇对人绒毛孕酮分泌的影响

本工作利用灌流技术观察了四种不同浓度的乙醇(0.5％、1％、2.5％、5％)对妊娠早期人工流产新鲜胎盘绒毛分泌孕酮的影响。结果表明,乙醇具有促进孕酮分泌的作用,并存在剂量依赖的关系。提示乙醇可能破坏胎盘激素内分泌的平衡,从而影响胎儿的正常生长与发育。     

Prevalence of neutralizing antibodies to adenoviral serotypes 5 and 35 in the adult populations of The Gambia, South Africa, and the United States

One of the major limitations of the use of adenoviruses as gene therapy vectors is the existence of preformed immunity in various populations. Recent studies have linked failure of adenoviral gene therapy trials to the presence of antiadenoviral neutralizing antibodies (NAb). Understanding the distribution and specificity of such antibodies will assist in the design of successful recombinant adenoviral gene therapies and vaccines. To assess the prevalence of NAb to adenovirus serotypes 5 and 35 (Ad5 and Ad35), we analyzed serum samples from adult immunocompetent individuals living in The Gambia, South Africa, and the United States by using a neutralization assay. Serum samples were incubated with A549 lung carcinoma cells and adenoviruses encoding enhanced green or yellow fluorescent proteins; results were analyzed by fluorescence microscopy and flow cytometry. Using this technique, we found a high prevalence of NAb against Ad5 in Gambian, South African, and U.S. subjects at both low and high titers. Conversely, all subjects displayed a low prevalence of NAb to Ad35; when present, anti-Ad35 NAb were seen at low titers. Because of the ability of adenoviruses to elicit systemic and mucosal immune responses, Ad35 with its low NAb prevalence appears to be an attractive candidate vector for gene therapy applications.     

抗体包被对红细胞变形性影响的研究

作者对抗体包被的红为性进行研究，发现抗体包被改变了红细胞的变形性，在我们研究的抗体量范围内，抗体量越多，红细胞的变形性越小，作者从血液流变学的角度对上述结果作了讨论，并提出了通过测定其对红细胞变形性的影响来比较准确地标定抗体效价的可能性。     

PENA方法的建立及与ELISA IgM检测CMV的比较

目的　介绍一种敏感、稳定、快速、简便的实验室检测CMV的方法 ,同时探讨该种新方法与ELISA检测CMV方法的优、缺点。方法　对 5 5 2例病人应用间接荧光免疫法测定细胞核中的特异病毒早期抗体 (PENA)和ELISA法测定IgM抗体。结果　PENA方法 :强阳性 88例 ,阳性率 15 4 9% ,弱阳性 2 73例 ,阳性率 5 9 4 6 % ;ELISA -IgM方法 :阳性 34例 ,阳性率6 16 %。结论　PENA方法操作简便 ,与ELISA方法相比较 ,可对CMV感染进行早期测定及诊断 ,并可区分既往感染和即时感染 ,具有敏感性和稳定性 ,是测定小儿CMV感染的一种较好的方法     

肺腺癌细胞微环境及转移与黏附分子表达的关系

目的研究肺腺癌细胞生长环境及转移性与黏附分子CD44v6和CD29的表达关系。方法将起源相同、转移性不同的两个肺腺癌细胞系AGZY和Anip分别用简便肿瘤多细胞球体(MTS)培养法培养，并设常规单层贴壁细胞培养对照。通过倒置显微镜、扫描及透射电镜观察MTS形成情况，并用免疫组化法分别对MTS及贴壁细胞上CD44v6和CD29表达进行检测。结果MTS培养成功，贴壁细胞与MTS在细胞结构及细胞连接结构上相似，两种MTS在形态及结构上差异无显著性。免疫组化结果显示，CD29在高转移性的Anip细胞及其MTS上呈阳性表达；在低转移性的AGZY细胞及其MTS上阴性表达。CD44v6在Anip和AGZY细胞及MTS上均呈阳性表达，差异无显著性。贴壁细胞与MTS上两种黏附分子表达均无差异。结论成功建立了一种简易制备MTS的方法。细胞生长方式(单层贴壁与MTS)可能不影响CD44v6和CD29的表达。CD29表达可能与肺腺痛转移性相关；CD44v6表达可能与肺腺癌转移无关。     

腰骶部SPR术中脊神经前后根定位的应用解剖

目的：为ＳＰＲ提供可靠的术中脊神经前、后根鉴别的解剖学依据。方法：在２０例成人脊柱标本上,去除后部结构,暴露整个马尾神经,对Ｌ１～Ｓ２节段的前后根进行形态学观察和测量。结果：脊神经后根位于马尾的后半部,前根则位于前半部。脊神经后根较相应的前根粗大,后根从Ｌ１～Ｓ１逐渐增大,以Ｓ１为最粗大;前根则以Ｌ３最粗大。相应前后根出硬脊膜前,有一段相互贴附并紧贴硬脊膜侧壁。结论：在多椎板切除ＳＰＲ术中前、后根的定位及鉴别,暴露时可根据前、后根出硬脊膜前的相互贴附;在限制性椎板切除时则可通过脊髓外侧索和Ｌ１前、后根之间的最下端的齿状韧带加以鉴别