抗感染重组合异种骨对犬污染性桡骨缺损的一期植骨修复作用

目的探讨抗感染重组合异种骨(anti-infective reconstituted bone xenograft,ARBX)对犬污染性桡骨缺损的一期植骨修复的效果. 方法在重组合异种骨(reconstituted bone xenograft,RBX)基础上,结合抗生素局部缓释技术,制备具有较强抗感染能力和较高成骨作用的ARBX.取成年杂种犬8只,于双侧桡骨中上段制成15 mm节段性骨缺损,在缺损处注入5×106 CFU/ml金黄色葡萄球菌1 ml,静置15分钟后,于双侧缺损区分别植入ARBX、RBX,并用钢板固定.术后6个月对存活的6只犬进行取材,通过解剖学、X线片、组织学及细菌学检查,比较ARBX和RBX一期植骨修复犬污染性桡骨缺损的效果. 结果术后6个月,ARBX侧有5只完全修复,1只中央部3 mm缺损未修复,均无骨髓炎表现,标本细菌培养均为阴性.RBX侧有1只部分修复,5只未能修复,残留8～13 mm缺损,均有明显骨髓炎表现,标本细菌培养均为阳性. 结论 ARBX具有较高成骨活性和较强的抗菌能力,能够一期植骨修复细菌污染性骨缺损.     

胃癌单克隆抗体在裸鼠移植瘤中的免疫定位和显像

本文采用Ｉｏｄｏｇｅｎ法将鼠抗人胃癌单克隆抗体ＲＳＦ９（ＩｇＭ）予以１３１Ｉ标记，研究ＲＳＦ９在荷人胃癌裸鼠中的定位和显像能力。结果表明，ＲＳＦ９在体内能特异性地与肿瘤组织结合，Ｔ／ＮＴ比值随时间延长逐渐升高，９６ｈＴ／ＮＴ比值均大于２．５，瘤／血比值为２．６９，肿瘤定位指数达５．１８，ＳＰＥＣＴ得到清晰的肿瘤图像。ＲＳＦ９具有良好的体内导向定位能力。ＩｇＭ型单抗也可用于肿瘤显像。     

吲哚美辛对人结肠癌HCT116和SW480细胞的影响

目的：探讨吲哚美辛对人结肠癌HCT116和SW480细胞的影响。方法：体外培养细胞，采用MTT法分别检测吲哚美辛作用后两系细胞的生长情况，计算半抑浓度（IC50）；体内建立裸鼠皮下移植瘤模型，喂服吲哚美辛3 mg/(kg·d)共4周，隔日测瘤结节体积及鼠重，评价吲哚美辛的抑瘤效果。结果：吲哚美辛作用于结肠癌HCT116和SW480细胞48 h后，细胞的生长均受到明显抑制，呈剂量依赖效应，IC50分别为 (318.2±12.7) μmol/L和 (701.4±29.5) μmol/L；吲哚美辛显著减慢裸鼠皮下移植瘤的生长，用药4周后抑瘤率达44.6%，未见明显毒性反应。结论：吲哚美辛能抑制不表达环氧合酶的人结肠癌细胞（HCT116和SW480）生长，间接说明其抗癌作用不完全依赖环氧合酶途径，还存在其它的可能机制。     

Feeding NOD mice with pig splenocytes induces transferable mechanisms that modulate cellular and humoral xenogeneic reactions against pig spleen or islet cells

We have reported previously that oral administration of pig cells to NOD mice modified xenogeneic cellular response against pig islet cells (PICs), and hypothesized that it may have induced active suppression. This preliminary report evaluated only the effect of feeding pig cells by 'primary' proliferation, i.e. when splenocytes from fed mice are confronted with pig cells in vitro. The present study also considered 'secondary' proliferation and cytokine production after feeding and subsequent in vivo graft of pig cells. Additionally, serum IgM and IgG isotypes were quantified by ELISA using pig target cells. Induction of active mechanism by feeding was hypothetical, which led us here to transfer splenocytes from mice fed pig spleen cells (PSC) and evaluate 'primary' (after transfer) and 'secondary' (after transfer and subsequent graft of pig cells) proliferations and cytokine secretions in recipient mice. We also determined whether the effects of feeding pig cells persisted after depression of suppressor mechanisms by cyclophosphamide. Mice fed with PSC displayed increased 'primary' splenocyte proliferation to PSC or PIC (P < 0.0001), while 'secondary' responses were decreased (P < 0.03) in those fed PSC and subsequently grafted with PSC. The increased 'primary' and decreased 'secondary' proliferations were reduced (P < 0.04) by pretreatment with cyclophosphamide. The IL-10/ and IL-4/IFNgamma ratios produced in response to PSC increased (P < 0.04) in mice fed and grafted with PSC compared to those grafted only with PSC. IgM and IgG levels against pig cells were, respectively, increased (P < 0.04) and decreased (P < 0.04) in mice fed and grafted with PSC. IgG2a and IgG2b, but not IgG1, levels were lower (P < 0.01). These effects of feeding PSC on 'secondary' proliferation, cytokine and antibody productions, were not detected when mice were fed PSC only after graft with PSC. Transfer with splenocytes from mice fed PSC increased 'primary' proliferation of splenocytes from recipient mice in response to PSC (P < 0.02) or PIC (P < 0.05). After transfer with splenocytes from PSC-fed mice and graft with PSC, 'secondary' proliferation to pig cells were reduced (P < 0.04), and the IL-10/IFNgamma ratio produced in response to PSC was increased fourfold. Thus, oral administration of PSC induces active transferable mechanisms, characterized by a biphasic pattern with early increased 'primary' xenogeneic cellular reactions to both PSC and PIC, followed by decreased 'secondary' responsiveness and a concomitant shift of the Th1/Th2 balance towards greater Th2 influence. Decreased responsiveness may be due to active suppression, even though induction of anergy or deletion cannot be excluded.     

血红素加氧酶1延长异种心脏移植存活的机制研究

探讨血红素加氧酶1(heme oxygenase-1,HO-1)在器官移植中抗急性血管排斥反应的作用。通过建立豚鼠到SD大鼠异位心脏移植模型,用血红素(hemin)分别诱导供者和受者,上调HO-1基因表达;用眼镜蛇毒因子、环孢素A抑制超急性排斥反应;观测供者心脏存活时间,并分别检测心脏组织HO-1表达、受者血清异种抗体IgM的变化及异种抗体IgM和C3在血管内膜的沉积;采用TUNEL方法检测心脏组织细胞凋亡;RT-PCR方法测定组织CD40L mRNA表达水平。结果显示:上调HO-1表达能明显延长心脏移植存活时间,抑制异种抗体IgM表达和在血管内膜的沉积,减少心肌细胞的凋亡并且抑制CD40L mRNA的表达。该结论表明HO-1通过介导CD40-CD40L共刺激途径抑制大鼠异种心脏移植后急性血管排斥反应,延长心脏移植存活时间。     

复合rhBMP2的异种骨的研制及成骨活性

目的：研制新型具有诱导成骨活性的异种骨植骨材料。方法：在重组合异种骨（RBX）基础上,以基因重组人BMP2（rhBMP2）取代从牛皮质骨中提取的牛BMP,与去抗原牛松质骨载体（BCB）复合,制成复合rhBMP2的异种骨（rhBMP2/BCB）,并采用小鼠股部肌袋模型,通过组织学、骨计量学方法检测rhBMP2/BCB的诱导成骨活性。结果：实验组（rhBMP2/BCB组）术后7d在小鼠肌袋可诱导软骨生成,14d形成纺织骨,21d改建成板状骨并形成大量骨髓;对照组（BCB组）于术后各时间点均未见有软骨成骨形成。实验组的碱性磷酸酶活性和钙含量均高于对照组,有非常显性差异（P＜0．01）。结论：rhBMP2/BCB具有较好的骨诱导能力,是一种较理想的植骨材料。     

袖套法豚鼠至大鼠异种全胰十二指肠移植模型的建立

目的为研究超急性排斥反应及对策,建立异种胰腺移植模型。方法以豚鼠和大鼠为供受者,用袖套法吻合静脉建立异种全胰十二指肠移植模型。结果共行 ４２次手术,成功 ３８例,均有内分泌功能,移植有效率为 １００％。结论本模型具有操作简单,冷缺血及腹主动脉阻断时间短,不易形成血栓及吻合口漏等优点,为一较实用的研究异种胰腺移植模型。     

豚鼠至大鼠异种小肠移植超急性排斥的初步观察

目的 建立袖套法豚鼠至大鼠异种小肠移植模型,初步观察异种小肠移植超急性排斥反应的过程。方法 行异种异位全小肠移植,移植小肠脾性系膜上动脉（腹主动脉）与受体肾以下腹主动脉作端侧吻合,切除受体左肾,移植小肠肠系膜上静脉（门静脉）与受体左肾静脉行袖套吻合;在手术显策镜下观察超急性排斥的大体变化。结果 共实施异种小肠移植４０例,成功３４例,供受体手术时间平均１５０ｍｉｎ,血管吻合成功率达９０％。再灌流后１     

Inhibition of the epidermal growth factor receptor tyrosine kinase by PD153035 in human A431 tumors in athymic nude mice

Summary PD153035 is a potent (K_i=6 pm) and specific inhibitor of the epidermal growth factor (EOF) receptor tyrosine kinase that suppresses tyrosine phosphorylation of the EGF receptor in A431 cells at nanomolar concentrations in cell culture. We have examined the pharmacokinetics of this compound and its ability to rapidly suppress phosphorylation of the EGF receptor in A431 human epidermoid tumors grown as xenografts in immunodeficient nude mice. Following a single i.p. dose of 80 mg/kg, the drug levels in the plasma and tumor rose to 50 and 22 M within 15 minutes. While the plasma levels of PD153035 fell below 1 M by 3 hours, in the tumors it remained at micromolar concentrations for at least 12 hours. The tyrosine phosphorylation of the EGF receptor was rapidly suppressed by 80–90% in the tumors. However receptor phosphorylation returned to control levels after 3 hours despite the continued presence of the drug at concentrations which, based on previousin vitro results, were predicted to maintain inhibition. EGF-stimulated tyrosine kinase activity in tumor extracts was decreased and recovered in parallel with the effects of PD153035 on receptor phosphorylation though the activity had reached only about half of the control activity after three hours. These results demonstrate the potential for using small molecule inhibitors to inhibit the EGF receptor tyrosine kinasein vivo, though a fair evaluation of their potential anti-cancer activity will have to wait for solutions to problems with sustained delivery which may allow us to maintain suppression of EGF receptor phosphorylation.