Lines of Murine Oligodendroglial Precursor Cells Immortalized by an Activated neu Tyrosine Kinase Show Distinct Degrees of Interaction with Axons In Vitro and In Vivo

Replication-defective retroviruses expressing the t- neu oncogene, or a hybrid protein with the neu tyrosine kinase linked to the external region of the human epidermal growth factor receptor ( egfr-neu ), were used to establish lines of murine oligodendroglial precursor cells. Differentiation of the t- neu lines into myelin-associated glycoprotein (MAG)-positive oligodendrocytes was induced by dibutyryl cAMP, and the egfr-neu line showed limited differentiation in vitro upon withdrawal of epidermal growth factor. Cerebellar granule cell neurons expressed mitogens for the cell lines. Upon transplantation into demyelinated lesions, t- neu line cells engaged with the demyelinated axons whereas the egfr-neu line cells differentiated further and ensheathed the axons. These cell lines thus interact with neurons in vitro and in vivo and can be used as tools to define the molecules involved in different stages of neuron-glia interaction.     

Cannabinoid receptor down-regulation without alteration of the inhibitory effect of CP 55,940 on adenylyl cyclase in the cerebellum of CP 55,940-tolerant mice

The objective of this study was to determine whether the development of tolerance to CP 55,940, a potent cannabinoid agonist, was due to changes in the receptor or second messenger system. ICR mice treated with CP 55,940 (2 mg/kg) twice a day for 6 and one-half days developed a high degree of tolerance to the pharmacological effects of CP 55,940. The ability of CP 55,940 to produce motor hypoactivity, hypothermia and immobility was reduced 163-, 97- and 19-fold, respectively. Evaluation of 3H-CP 55,940 binding to rat brain membranes indicated no difference in receptor affinity between the vehicle- and CP 55,940-treated animals. However, these binding studies revealed a 50% decrease in receptor number in the cerebellum of the CP 55,940-tolerant mice. Although cAMP is generally considered to be the second messenger for cannabinoid receptors, little difference was observed in the inhibitory effects of CP 55,940 on adenylyl cyclase activity in cerebellum between vehicle and drug-treated mice. However, there was an increase in receptor mRNA which suggests a compensation for receptor loss. There are several possible explanations for these results. There may be sufficient spare receptors such that CP 55,940-tolerant mice are capable of producing a maximal effect on the second messenger system. On the other hand, one could conclude that cannabinoid receptor down-regulation does not account for the development of tolerance to all of the effects of CP 55,940 in mice.     

10Gyγ线照射后小鼠两相邻肠段运动变化

本文用同时记录两相邻空肠段的收缩活动来观察经10Gyγ线照射后小肠运动的变化,以了解照射后是否出现逆蠕动,以便进一步分析肠套叠形成的原因.结果表明,照射后两相邻肠段出现强度不一的收缩活动,并且可以产生逆蠕动;但是这种逆蠕动发生的机率是不大的.本实验未观察到逆蠕动发生的规律性.因此,逆蠕动的产生可能是照射后发生肠套叠的部分原因.     

腺嘌呤核苷酸载体的功能和表达与心力衰竭

腺嘌呤核苷酸载体（ANT）是一种位于线粒体内膜上的转运蛋白，它在组织细胞能量产生和消耗的耦联中起关键性作用。作者就ANT的功能和表达情况及其与心力衰竭之间的关系作一综述。     

金丹肝泰1号对大鼠急性肝损伤防治作用的实验研究

用D-氨基半乳糖（D-GaIN）制备大鼠急性肝损伤模型。方法：检测血清丙氨酸氨基转氨酶（ALT）和血清天门冬氨酸氨基转氨酶（AST）的活性，观察光镜下肝组织的病理学改变，探讨对急性肝损伤的保护作用。结果：口服浸膏可显降低急性肝损伤大鼠血清ALT和AST水平，减轻肝细胞的变性坏死，其作用强度与肝炎宁相当，但弱于联苯双酯。     

股骨颈骨折粗细双螺钉内固定生物力学研究

股骨颈骨折内固定方法繁多。本文采用一粗一细加压螺纹钉，采用先进电阻应变仪方法，对股骨颈的应力分布规律在中立、外展、内收不同位置上施加50kg荷载压力．通过电阻应变计测定一耗一细两钉所承受拉、压应力优于其它内固定形式。     

近节指骨段屈肌腱鞘不同范围损伤对肌腱功能的影响

目的 探索手指屈肌腱在近节指骨段不同范围损伤时对屈指肌腱功能的影响。方法 采用12只成人尸体手指。实验分为:第一阶段屈指肌腱完整,以后四个阶段依次沿近节指骨掌侧小线闭开小央1/4、1/2、3/4及全长。在掌指关节被动屈80°和掌指关节屈80°同时近侧指关节屈100°时,测量指浅屈肌腱(FDS)和指深屈肌腱(FDP)的滑动距离。根据肌腱力臂和滑动距离的关系,得出屈指肌腱在掌指关节处和近侧指间关节及肌腱在近节指骨段的弓弦畸形程度。结果 腱鞘中央1/4切开时,指屈肌腱的滑动距离、力臂均无显著变化;1/2切开后,单纯屈曲掌指关节时的FDS腱和掌指、近节指间关节屈曲时的FDS、HDP腱的滑动距离和力臂较腱鞘完整时显苫增大(P<0.05);切开3/4长度后,FDS、FDP腱滑动距离均有统计学意义变化,FDS、FDP腱力臂平均增加8～9％;全切开腱鞘,FDS、FDP腱滑动距离变化正统计学上有高度显著性(P<0.01),两腱力臂分别增加16％和15％。随腱鞘切开范围增大,FDS、FDP在近节指骨段的弓弦畸形程度也越来越大。结论 从肌腱的生物力学变化可见,近节指骨段腱鞘的小范围损伤如中间1/4以内损伤时,对肌腱功能影响小,可以不予修复;若损伤超过1/2长度,尤其对腱鞘全长损伤,应予以修复以恢复肌腱功能。     

小儿先天性髋关节脱位近年来应用术式的演变及其评估

本文介绍本院近４年来小儿先天性髋脱位治疗应用术式的演变。由２０多年来一直喜欢用骨盆截骨术演变为近１年来用得最多的是造盖术。近４年共手术４６３例，５６５髋。实践证明：比起骨盆截骨术，造盖术显得更简便，侵袭小，不需二次手术拔除内固定针。因在我国大龄髋脱位偏多，造盖术更适合我国国情。经过一些改进，可以克服造盖折断和吸收问题。     

Observation on 108 Normal Ophthalmic Arteries in 80 Patients by Digital Subtraction Angiography

By digital subtraction angiography(DSA), the authors made observations on 108 normal ophthalmic arteries in 80 patients with regard to the origins, courses, branching, morphology and anastomoses of the vessels. The merits and demerits of DSA in observing the ophthalmic artery were discussed. Eye Science 1994; 10: 157- 162.     

胼胝体发育不全的MRI表现

对６例胼胝体发育不全的ＭＲＩ表现进行了分析。矢位像可清楚显示胼胝体的形态学变化，冠位或矢位像较轴拉像更易确认三脑室的移位。ＭＲＩ的多方向成像和高组织分辩率较ＣＴ更有利于对胼胝体发育不全及所合并的其他中枢神经系统异常的诊断，故可做为首选的影像学检查方法。