阿糖胞苷纳米粒的制备及其释药规律研究

采用乳化聚合法制备阿糖胞苷纳米粒，研究其体内外释药特性。结果表明阿糖胞苷纳米粒体外释药规律符合双指数方程，有明显的缓释作用。在家兔体内的药物动力学过程符合二室模型，与阿糖胞苷注射剂相比，t1／2β和MRT延长，CL降低，表明阿糖胞苷纳米粒可显著延长阿糖胞苷在体内存留时间，具有明显的缓释特征。     

大鼠肝移植排斥反应期一氧化氮合酶的动力学变化

目的 探讨供体特异性输血（DST）预处理后大鼠同种肝移植物一氧化氮合酶（NOS）的动力学变化。方法 观察同基因肝移植（Ⅰ组），同种肝移植（Ⅱ组），DST预处理的同种肝移植（Ⅲ组）术后NOS的表型及亚硝酸盐/硝酸盐，细胞因子的动态变化。结果 Ⅱ组血中亚硝酸盐/硝酸盐，INF-α，TNF-α浓度明显增高，免疫组化显示，Ⅱ组移植物中macNOS^ 及ED1^ ,ED2^ 细胞数明显增多，Northern blot分析，Ⅲ组移植物中IL-10和TGF-BmRNA呈高水平表达；Ⅱ组移植物的iNOS和IL-12mRNA水平明显高于其他组。结论 DST预处理的移植物处于免疫无应答状态，NOS被抑制与TH2及TH3类细胞因子高表达有关。     

Peripheral nerve regeneration by microbraided poly(L-lactide-co-glycolide) biodegradable polymer fibers

Tiny tubes with fiber architecture were developed by a novel method of fabrication upon introducing some modification to the microbraiding technique, to function as nerve guide conduit and the feasibility of in vivo nerve regeneration was investigated through several of these conduits. Poly(L-lactide-co-glycolide) (10:90) polymer fibers being biocompatible and biodegradable were used for the fabrication of the conduits. The microbraided nerve guide conduits (MNGCs) were characterized using scanning electron microscopy to study the surface morphology and fiber arrangement. Degradation tests were performed and the micrographs of the conduit showed that the degradation of the conduit is by fiber breakage indicating bulk hydrolysis of the polymer. Biological performances of the conduits were examined in the rat sciatic nerve model with a 12-mm gap. After implantation of the MNGC to the right sciatic nerve of the rat, there was no inflammatory response. One week after implantation, a thin tissue capsule was formed on the outer surface of the conduit, indicating good biological response of the conduit. Fibrin matrix cable formation was seen inside the MNGC after 1 week implantation. One month after implantation, 9 of 10 rats showed successful nerve regeneration. None of the implanted tubes showed tube breakage. The MNGCs were flexible, permeable, and showed no swelling apart from its other advantages. Thus, these new poly(L-lactide-co-glycolide) microbraided conduits can be effective aids for nerve regeneration and repair and may lead to clinical applications.     

A Strain Device Imposing Dynamic and Uniform Equi-Biaxial Strain to Cultured Cells

The objective of this study is to design a new apparatus to allow the control of the magnitude and frequency of dynamic stretch applied uniformly to cells cultured on a silicon elastic membrane. The apparatus is designed to produce equi-biaxial dynamic stretches with area changes ranging from 0% to 55% and frequencies ranging from 0 to 2 Hz. Homogeneous finite strain analysis using triangles of markers was performed to compute the symmetric two-dimensional Lagrangian strain tensor on the membrane. Measurements of strain in both static and dynamic conditions showed that the shear component of the strain tensor (E_rc) was near zero, and that there was no significant difference between radial (E_rr) and circumferential (E_cc) components, indicating the attainment of equi-biaxial strain. Bovine aortic endothelial cells were transiently transfected with a chimeric construct in which the luciferase reporter is driven by TPA-responsive elements (TRE). The transfected cells cultured on the membrane were stretched. The luciferase activity increased significantly only when the cells were stretched by 15% or more in area. Cells in different locations of the membrane showed similar induction of luciferase activities, confirming that strain is uniform and equi-biaxial across the membrane. © 1998 Biomedical Engineering Society. PAC98: 8780+s, 8745-k, 8722-q     

大鼠咽肌前运动神经元的跨突触定位

支配咽肌的运动神经元位于疑核，控制凝核的前运动神经元位于孤束核。孤束核中的前运动神经元在控制吞咽运动中起着重要作用。但支配咽肌的前运动神经元位于孤束核的什么部位还不清楚。文内用假狂犬病毒研究字大鼠咽肌前运动神经元在孤束核中的定位。     

Endometrial and subendometrial blood flow measured during early luteal phase by three-dimensional power Doppler ultrasound in excessive ovarian responders

BACKGROUND: Impaired implantation in assisted reproduction cycles with high serum estradiol (E(2)) concentrations may be related to suboptimal endometrial perfusion. Endometrial and subendometrial blood flow were compared between excessive responders (serum E(2) on the day of HCG >20 000 pmol/l) and moderate responders (E(2) < or =20 000 pmol/l). METHODS: Three-dimensional (3D) ultrasound examination with power Doppler was performed 2, 4 and 7 days after HCG in 32 patients who did not have embryo transfer in order to measure endometrial thickness, pulsatility index (PI)/resistance index (RI) of uterine vessels, and endometrial volume, vascularization index (VI)/flow index (FI)/vascularization flow index (VFI) of endometrial and subendometrial regions. RESULTS: Excessive responders tended to have lower endometrial and subendometrial VI/VFI on HCG +2 and more absent endometrial/subendometrial blood flow. They had significantly higher endometrial FI and subendometrial VFI than moderate responders on HCG +7. Only in the excessive responder group, uterine PI/RI declined significantly from HCG +2 to HCG +7 and endometrial VI/VFI increased significantly from HCG +4 to HCG +7. CONCLUSION: Changes in uterine Doppler flow indices, and endometrial and subendometrial 3D power Doppler flow indices during the early luteal phase were significantly different between moderate and excessive responders.     

大鼠小脑皮质内突触素P38免疫反应产物的分布及年龄变化

用免疫组织化学方法结合图像分析研究突触素Ｐ３８免疫反应产物在Ｗｉｓｔａｒ大鼠小脑皮质的分布及年龄变化，结果显示：小脑皮质内的突触素Ｐ３８免疫反应产物呈板层分布，各层之间的 产物密度差异很大；在三个年龄组，小脑Ｖ，Ⅶ叶分子层突触素Ｐ３８免疫反应产物校正光密度值以青年组最大，成年组次之，老年组最小，各组间差异显著。     

氧分压在体监测仪的研制

作者报道一种稳定性较高的氧分压在体监测，为医学研究、临床诊断提供一种新的可靠的测试方法及设备，具有较大的应用价值。     

Non-invasive imaging of adaptive immunity using positron emission tomography

Summary: Non-invasive monitoring of adaptive immunity in infection, cancer, and autoimmunity remains a major challenge. Current techniques to monitor lymphocytes involve numeric and functional determinations of immune cells isolated from the peripheral blood (most often) and tissue (rarely). Invasive measurements are prone to sampling errors and are poorly reflective of the dynamic changes in the location, number, and movement of lymphoid cells. These limitations indicate the need for non-invasive whole-body imaging methodologies that allow longitudinal, quantitative, and functional analyses of the immune system in vivo . Positron emission tomography (PET), a clinically based whole-body imaging modality, has the potential to revolutionize diagnostics and therapeutic monitoring in both clinical and pre-clinical settings. This review discusses studies using PET to image adaptive immune responses in small animal models. We address the challenges inherent in assessing whole-body immunity with PET and recent developments that can improve its performance. Finally, we discuss work to translate PET immune imaging into clinical practice.