Neurosarcoma of the face: MRI

Neurosarcoma is a rare tumour originating from the sheath of peripheral nerves. Facial lesions have been reported in about 20 patients. We describe the MRI appearances of neurosarcoma with histological correlation in three patients. The lesions lay in the submandibular region, the left parapharyngeal space and the right orbit. MRI showed a well-defined mass with mixed components. The lesions were moderately heterogeneous on T1-weighted images in two cases and on T2-weighted images in all cases. Gadolinium enhancement occurred in all cases to variable degrees. In two cases, small high signal foci were seen on T2-weighted sequences. MRI appearances of neurosarcoma are not specific. Received: 3 September 1996 Accepted: 26 November 1996     

S100 protein-immunoreactive primary sensory neurons in the trigeminal and dorsal root ganglia of the rat

The cell body size (cross-sectional area) of S100-immunoreactive (-ir) primary neurons was measured in the trigeminal (TG) and lumbar dorsal root ganglia (DRG). About a half of neurons exhibited S100-immunoreactivity (-ir) in the DRG (44.0%) and TG (59.0%). DRG neurons with cell bodies >1200 μm² mostly exhibited S100-ir (96.5%), whereas S100-ir DRG neurons <600 μm² were rare (8.0%). 36.6% of DRG neurons in the cell size range 600–1200 μm² showed the ir. TG neurons >800 μm² mostly exhibited S100-ir (93.1%), whereas those <400 μm² were devoid of it (positive cells 10.5%). 58.3% of TG cells in the range 400–800 μm² contained S100-ir. Double-immunofluorescence method revealed the co-expression of S100 and other calcium-binding proteins. Parvalbumin-ir neurons mostly exhibited S100-ir in the DRG (97.4%) and TG (97.0%). The co-expression of S100 and calbindin D-28k was very rare in the DRG, because the DRG contained few calbindin D-28k-ir neurons. Unlike in the DRG, numerous neurons co-expressed S100- and calbindin D-28k-ir in the TG. Most calbindin D-28k-ir TG neurons were also immunoreactive for S100 (90.7%). Sub-populations of calretinin (CR)-ir neurons co-expressed S100-ir in both the DRG (68%) and TG (50.0%). Virtually all CR-ir neurons >1400 μm² co-expressed S100-ir in the DRG (100%) and TG (95.9%). CR-ir neurons <800 μm² were rarely exhibited S100-ir (DRG 18.0%, TG 21.9%). 71.3 and 60.5% of CR-ir neurons in the range 800–1400 μm² co-expressed S100-ir in the DRG and TG, respectively. The present study indicates that S100 is closely correlated to the primary neuronal cell size in the DRG and TG.     

应用同种动脉治疗主动脉根部病变

报告５例采用同种动脉（ＨＡＶ）治疗５例主动脉根部病变（主动脉瓣狭窄１例，关闭不全４例）。男３例，女２例；年龄１３～４７岁。病因为细菌性心内膜炎２例（包括先天主动脉瓣二瓣化畸型１例），Ｍａｒｆａｎ综合征２例，风湿性主动脉瓣关闭不全１例。术中采用同种主动脉全根置换３例（Ｂｅｎｔａｌｌ手术），其中１例用ＨＡＶ上的二尖瓣前叶加宽主动脉瓣环（Ｍａｎｏｕｇｕｉａｎ手术），余２例用自体肺动脉移置主动脉根部，另取同种肺动脉做原位移置（Ｒｏｓｓ手术）。结果死亡１冽，４例存活，且无并发症发生。术后超声心动图提示主动脉根部良好，无主动脉瓣反流。随访２．５～３．５年疗效满意。     

血管植入神经移植段修复神经缺损的实验研究

54只大白鼠随机分三组，用不同方法修复坐骨神经缺损，术后60天和90天取材，作电生理、组织学和电镜观察的比较，结果表明：游离神经移植＋血管植入方法和带血管蒂神经移植效果同样好，二者均显著优于单纯游离神经移植。     

神经生长因子对小鼠突触体内Ca^2＋水平的调节作用

观察了多次海马内微注射ＮＧＦ对小鼠突触体内游离钙水平的影响，并在离体情况下观察ＮＧＦ对ＥＧＴＡ和ＣａＣｌ２分别造成突触体内低钙和高钙状态的调节作用。结果如下：（１）在体实验表明，一定剂量的ＮＧＦ可显著降低老年小鼠海马突触体内游离钙水平（Ｐ＜００５）；（２）离体实验表明，当突触体游离钙水平降低时，适当剂量的ＮＧＦ具有升高游离钙水平的作用；而突触体内游离钙水平升高时，则ＮＧＦ有降低游离钙水平的作用。提示ＮＧＦ对游离钙水平的双向调节作用可能是ＮＧＦ改善老年性记忆衰退的作用机制。     

门脉高压性胃病患者的胃壁血气变化

作者观测了４３例门脉高压症患者股动脉血ＰＯ２、胃网膜有动静脉胃壁支血ＰＯ２、胃壁支静脉及肘静脉血ｐＨ、ＨＣＯ３－和胃网膜右静脉压力，其中２３例并有非出血期门脉高压性胃病。结果表明：①门脉高压症患者的股动脉血ＰＯ２低于对照组；②门脉高压症患者胃网膜右动静脉胃壁支血氧分压差低于对照组，胃网膜右静脉压力高于对照组，胃壁支静脉血ｐＨ和ＨＣＯ３－低于对照组和同组肘静脉血。并有门脉高压性胃病者这些变化更为显著。提示门脉高压性胃病的发病机制在于门脉系压力增高、胃粘膜下动静脉短路开放、胃粘膜缺血缺氧和胃壁局部酸中毒。     

Comparative bactericidal exposures for selected oral bacteria using carbon dioxide laser radiation

Although relatively high CO2 laser energies have been shown to sterilize root canals, the response of several bacterial strains to decreasing exposures of CO2 laser energy remains unknown. Freshly grown bacterial cells were irradiated on glass microscope coverslips. A comparison of equivalent energy exposures with differing parameters was made on the bacterial viability. No statistically significant difference was found in the energy required to kill closely related bacterial species. However, the energy density required to kill greater than 99.5% of the bacteria is less than 200 J/cm2, much less than that shown to sterilize in a previous study.     

胎盘型谷胱甘肽S转移酶mRNA在大鼠肝癌癌前病变组织中的原位表达

应用原位杂交技术，观察了二乙基亚硝胺（ＤＥＮ）诱发大鼠肝癌前病变组织中胎盘型谷胱甘肽Ｓ转移酶（ＧＳＴ－Ｐ）ｍＲＮＡ的表达。结果显示，ＧＳＴ－ＰｍＲＮＡ主要在癌前病变肝组织中的变异灶及灶外卵圆形细胞内表达，且在变异灶间或和同一灶内阳性细胞间表达程度不尽一致，而正常肝、再生肝组织中未见其表达。提示在分子水平上变异灶细胞及卵圆型细胞可能成为实验性肝癌的癌前期细胞     

握力大小与前臂肌肉表面肌电活动模式的相关性研究

目的 研究手部握力大小与前臂肌肉表面肌电信号特征的相关性.方法 9名健康被试者参加了试验,包括最大自主收缩力(maximum volunteer contraction,MVC),80% MVC及40% MVC,记录指浅屈肌和腕长伸肌的表面肌电信号,并采用均方根和小波分析方法提取其特征参数;运用SPSS软件统计以被试者自身的MVC为基准的不同握力水平的相对特征值,使不同的被试者具有可比性.结果 对于单个被试者握力水平与表面肌电活动模式存在正相关性,即握力越大则对应的表面肌电信号的特征值也越大;对于所有的被试者这种正相关性也存在.结论 握力水平与肌肉活动模式具有相关性,这提示通过表面肌电信号的特征值不但可以预测握力的大小,还可用于运动功能测试及康复的评价.     

牛黄栀子配伍对大鼠局灶性脑缺血再灌注不同时段神经生长因子（NGF）含量的影响

目的:通过检测牛黄、栀子配伍对大鼠局灶性脑缺血再灌注不同时段神经生长因子(NGF)含量的影响,探讨治疗缺血性中风在该作用环节不同时段的作用特点,研究其配伍阻抑脑缺血级联反应的时序特征。方法:用线栓法建立大鼠大脑中动脉缺血再灌注模型,观察牛黄、栀子及二者配伍对缺血再灌注24小时和72小时两个时段大鼠脑组织NGF含量的影,响。结果:缺血再灌注损伤可明显抑制脑组织NGF的表达,从而削弱了机体的自身保护机制;再灌注24小时,牛黄、栀子均可促进NGF的表达,而二者配伍后作用明显降低:再灌注72小时,牛黄的作用不显著,栀子可明显增强NGF的表达,二者配伍与栀子的作用相当,未显示出明显的配伍效应。结论:中药配伍的作用不是简单的效应累加,而是依据作用环节及作用时间的不同表现为不同的时空特征。