立体着床模型--小鼠囊胚与子宫内膜的共培养

目的:建立小鼠囊胚体外着床的三维模型,为着床机制的研究提供重要工具.方法:将小鼠囊胚与其自身子宫内膜分别共培养在空气、含500,750和950 mL/L O2的混合气体与组织培养液的气液界面上,比较不同O2浓度下小鼠囊胚的贴附率,确定体外共培养的最佳O2浓度;同时将确认有囊胚贴附的子宫内膜取出作HE染色.结果:不同O2浓度下,囊胚的贴附率分别为64.75%,47.86%,42.37%和30.97%,x2检验提示其差异有显著性(x2=28.145,P=0.000);且随着混合气体中O2浓度的逐渐升高,囊胚贴附率呈逐渐降低趋势.因此50 mL/L CO2 950 mL/L空气对囊胚与子宫内膜的共培养是最有利的;同时,囊胚贴附子宫内膜后并无扩展行为而是直接侵入子宫内膜.结论:50 mL/L CO2 950 mL/L空气最有利于囊胚与子宫内膜的共培养;且囊胚贴附子宫内膜后不发生外延生长,而是直接侵入子宫内膜.本实验成功地建立了小鼠囊胚体外着床的三维模型.     

“Chain-link” combined tissue transfer for the reconstruction of the mandible

We describe a procedure for “chain-link” combined tissue transfer connecting the vascular pedicle of a deep circumflex iliac flap with that of a forearm flap after wide resection of the mandible. Combination of these flaps facilitated the reconstruction of the defect in both intra- and extraoral soft tissue and the mandibular bone. This method is useful when cervical recipient blood vessels are limited due to the wide resection of the primary tumor and radical neck dissection.     

金属换热器传热过程的数学模型及应用

应用蒙特卡洛法仿真辐射式金属换热器内的辐射传热过程，建立了换热器综合传热的数学模型，利用概率论原理，把辐射能迁移过程仿真为一定累积概率分面下的随机过程，该模型能较好地反映换热器内传热过程的真实情况，可以计算出换热器内烟气、筒壁、空气的温度和壁面热流分布，以及研究烟气进口温度、换热器筒径和狭逢宽度对换热效果的影响。     

逆转录病毒载体介导的外源性主要组织相容性抗原复合体基因转移及其在T细胞的表达

目的 建立一个在胸腺内表达外源性主要组织相容性抗原复合体(MHC)抗原的实验模型,为下一步研究作准备。方法 应用逆转录病毒载体介导的基因转移技术,首次将外源性MHC基因转移到T淋巴表达并应用聚合酶链反应(PCR)及反转录聚合酶链反应(RT-PCR)检测转染T细胞DNA及mRNA。结果 外源性MHC基因已整合到靶细胞染色体DNA并有效地转录;单克隆抗体免疫荧光染色流式细胞仪检测显示在转染T细胞膜有外源性MHC分子表达;转染效率为46.2％。结论 外源性MHC基因可以转移到T细胞稳定表达,为今后的研究提供了经验。     

Transitional progressive multiple sclerosis: MRI and MTI findings

Transitional progressive multiple sclerosis (MS) is quite an unusual form of presentation and course of the disease. A case with this progressive form is presented and brain MRI and MTI findings are discussed in relation to the possible insight they may provide for understanding the mechanisms that determine progressive disability in MS.     

Spectrum of looping disturbances in stage 34 chicken hearts after retinoic acid treatment

Background: In a recently developed chick model the teratogen retinoic acid has appeared to induce a spectrum of double outlet right ventricle, which needs further detailed evaluation. It is known that retionic acid is able to induce cardiac malformations. Although the exact mechanism is not known, an interaction with neural crest cell function is thought to exist. Methods: After treatment with 1 μg all-trans retinoic acid at Hamburger and Hamilton stage 15 and reincubation until stage 34 of development 41 chicken embryos were evaluated macroscopically and microscopically, supported by graphic reconstructions. These retinoic acid treated embryos were compared with a control group (n = 8). Results: The retinoic acid treated embryos could be divided in three groups. Group 1 (23/41) had an intact septum, group 2 (11/41) had an isolated ventricular septal defect (VSD), and group 3 (7/41) had a double outlet right ventricle (DORV). Besides, in the group with an intact septum 11 hearts showed an abnormal course of the subaortic outflow tract. In the group with DORV a straddling tricuspid orifice (7/8) and a double inlet left ventricle (1/8) could be distinguished. Considering the external contour, the hearts in the DORV group all showed a dextroposed arterial pole. Malformed pharyngeal arch arteries were found in all three groups (11/41) and with a great diversity. Conclusions: The present cardiac malformations in the chicken as a result of retinoic acid treatment are part of a continuous spectrum, varying from hearts with an intact ventricular septum and a normal course of the subaortic outflow tract to a double outlet right ventricle with a straddling tricuspid orifice or even a double inlet left ventricle. A remarkable observation in this spectrum concerns the correlation of malformations of the inflow and outflow tracts, which is explained as a cardiac looping disturbance. The disturbance of the looping process seems to lead to malalignment of septal components, although, in the chick, retinoic acid does not in general interfere with the formation of these septal components themselves. © 1995 Wiley-Liss, Inc.     

囊胚期冷冻胚胎移植的临床应用探讨

目的探讨囊胚期冷冻胚胎移植的临床应用价值.方法对2002年10月～2003年12月在湘雅医院生殖医学中心接受囊胚培养并行囊胚期冷冻胚胎移植的病例进行分析,了解囊胚期与卵裂期冷冻胚胎解冻后的胚胎成活率、植入率及妊娠率.结果冷冻囊胚解冻后胚胎数、胚胎成活率、植入率和妊娠率与卵裂期冷冻胚胎无显著差别(P＞0.05),囊胚解冻后经15 h过夜培养,42枚中有22枚成活,其中8枚Ⅰ,Ⅱ级继续发育或囊胚腔扩张,3例获得妊娠,妊娠率为37.5%.结论囊胚期冷冻胚胎移植同样能达到卵裂期冷冻胚胎移植的临床效果,同时增加解冻与移植间隔时间可更好地选择冻融囊胚移植,对提高妊娠率可能有一定意义.     

胚胎玻璃化冷冻技术的临床应用(附成功分娩1例报道)

目的 探讨胚胎玻璃化冷冻技术的临床应用效果。方法 运用玻璃化冷冻技术保存75例患者的397个胚胎，复苏13例69个胚胎，并根据患者的情况进行胚胎移植。结果 69个胚胎中，丢失3个，存活26个，存活率为39，4％。复苏后8例患者因胚胎质量差未移植，另外5例患者共移植了14个胚胎，其中1例获得单胎妊娠，分娩1名健康女要。结论 玻璃化冷冻技术简便、经济，并能够有效地冻存人类早期胚胎，可成为胚胎冷冻方法的另一个选择。     

垃圾转运站液压设备液压缸密封结构的改进

分析了压缩式垃圾转运站液压设备中常见的液压缸漏油原因,通过改进密封结构使液压缸的泄漏降低到最低限度,密封效果良好.