VEP及ERG联合检查1456例患者的临床分析

目的：分析视觉电生理检查病例，探讨该检查技术在视觉功能评定中的作用。方法：对2004年10月-2006年10月接受VEP及ERG检查的病例资料进行回顾性分析，以临床第一诊断为依据进行统计。结果：共1456例患者接受检查，年龄分布在4岁-87岁之间。疾病分类表明本组病例主要集中于白内障、眼外伤、视力下降原因待查、青光眼、视网膜脱离、视神经疾病及其他视网膜疾病等方面，占总数的91．28％。电生理检查结果主要表现为幅值降低或（和）潜伏期延迟。结论：视觉电生理学检查能够客观反映视觉功能，适用于临床诊断、术前预测、疗效评价、疾病预后、医学鉴定。但也有一定的局限性，须联合检查多项电生理指标并结合临床情况才能够作出正确结论。     

Defective ceramide synthases in mice cause reduced amplitudes in electroretinograms and altered sphingolipid composition in retina and cornea

Complex sphingolipids are strongly expressed in neuronal tissue and contain ceramides in their backbone. Ceramides are synthesized by six ceramide synthases (CerS1–6). Although it is known that each tissue has a unique profile of ceramide synthase expression and ceramide synthases are implicated in several neurodegenerative disorders, the expression of ceramide synthase isoforms has not been investigated in the retina. Here we demonstrate CerS1, CerS2 and CerS4 expression in mouse retina and cornea, with CerS4 ubiquitously expressed in all retinal neurons and Müller cells. To test whether ceramide synthase deficiency affects retinal function, we compared electroretinograms and retina morphology between wild‐type and CerS1‐, CerS2‐ and CerS4‐deficient mice. Electroretinograms were strongly reduced in amplitude in ceramide synthase‐deficient mice, suggesting that signalling in the outer retina is affected. However, the number of photoreceptors and cone outer segment length were unaltered and no changes in retinal layer thickness or synaptic structures were found. Mass spectrometric analyses of ceramides, hexosyl‐ceramides and sphingomyelins showed that C20 to C24 acyl‐containing species were decreased whereas C16‐containing species were increased in the retina of ceramide synthase‐deficient mice. Similar but smaller changes were also found in the cornea. Thus, we hypothesize that the replacement of very long‐chain fatty acyl residues by shorter C16 residues may affect the electrical properties of retina and cornea, and alter receptor‐mediated signal transduction, vesicle‐mediated synaptic transmission or corneal light transmission. Future studies need to identify the molecular targets of ceramides or derived sphingolipids in light signal transduction and transmission in the eye.     

糖尿病早期视网膜神经组织病理性改变研究进展

糖尿病视网膜病变（DR）是主要的致盲眼病。一直认为，视网膜微血管在糖尿病视网膜病理改变中发挥了主导作用。最近研究显示，在DR过程中有神经元的凋亡、神经胶质细胞功能障碍及视觉电生理等改变且先于视网膜微血管病变。本文综述近年来DR视网膜神经组织的国内外研究进展。     

局部应用医用生物蛋白胶释放NGF治疗大鼠视神经不完全损伤

目的研究局部应用医用生物蛋白胶释放神经生长因子(NGF)对大鼠视神经不完全损伤的治疗作用。方法将含有NGF生物蛋白胶放入培养基,于不同时间检测培养基中NGF的活性。将24只SD雄性大鼠随机分为假手术组(第1组),空白对照组(第2组),NGF肌注组(第3组)和实验组(第4组);每组6只。用手术造成左侧视神经不完全性损伤。第3组术后肌注NGF450U/d,共10d;第4组术中于损伤视神经局部注入生物蛋白胶0.2m(l含NGF450U),分别于术后第14、28天进行闪光视觉诱发电位(F-VEP)检测和视网膜节细胞(RGC)计数。结果 NGF在10h内逐渐从生物蛋白胶中释放至培养基。与第1组相比,第2、3、4组在术后第14天受损视神经的F-VEPP1潜伏期分别延长100%、45.5%和13.6%,波幅分别下降58.6%、44.6%和21.4%。术后第28天第2组受损视神经无电活动;与第1组相比,第3、4组P1潜伏期分别延长95.9%和34.9%,波幅分别下降60.9%和38.2%。各组不同时间F-VEPP1潜伏期和波幅均有明显差异(P0.05)。与第1组相比,第2、3、4组术后第14天受损侧RGC计数分别减少50.5%、34.4%和21.3%,第28天分别减少64.7%、47.6%和29.6%。各组之间受损侧RGC计数差异显著(P0.01)。结论医用生物蛋白胶可释放NGF。局部应用医用生物蛋白胶释放NGF对大鼠视神经不完全损伤疗效优于NGF肌肉注射。     

Flash扫描模式在儿童胸部检查中的应用研究

目的探讨双源CT Flash扫描模式在儿童胸部扫描中的应用价值。方法回顾性分析行胸部CT检查儿童患者60例,常规组及实验组各30例,分别从主观及客观两方面评价图像质量并进行比较,记录每例患者检查过程中接受的辐射剂量。结果两组的图像质量差异无统计学意义,实验组患者接受的辐射剂量远低于常规组。结论 CTFlash扫描模式在儿童胸部CT扫描中具有较大临床应用价值。     

运用Flash AS＋XML制作网络版《人体骨骼肌图解使用手册》

结合彩图和线图,介绍了利用Flash AS＋XML制作网络版《人体骨骼肌图解使用手册》,只要学习者输入正确的骨骼肌名称,便会立即呈现相关的图片、动画及文字说明的过程。该图解手册可使教学活动灵活方便,也便于学生复习使用,具有较高的使用推广价值。     

Conserved Modules Required for Drosophila TRP Function in Vivo

Transient receptor potential (TRP) channels are broadly required in animals for sensory physiology. To provide insights into regulatory mechanisms, the structures of many TRPs have been solved. This has led to new models, some of which have been tested in vitro. Here, using the classical TRP required for Drosophila visual transduction, we uncovered structural requirements for channel function in photoreceptor cells. Using a combination of molecular genetics, field recordings, protein expression analysis, and molecular modeling, we interrogated roles for the S4–S5 linker and the TRP domain, and revealed mutations in the S4–S5 linker that impair channel opening or closing. We also uncovered differential requirements for the two highly conserved motifs in the TRP domain for activation and protein stability. By performing genetic complementation, we found an intrasubunit interaction between the S4–S5 linker and the S5 segment that contributes to activation. This analysis highlights key structural requirements for TRP channel opening, closing, folding, and for intrasubunit interactions in a native context—Drosophila photoreceptor cells.SIGNIFICANCE STATEMENT The importance of TRP channels for sensory biology and human health has motivated tremendous effort in trying to understand the roles of the structural motifs essential for their activation, inactivation, and protein folding. In the current work, we have exploited the unique advantages of the Drosophila visual system to reveal mechanistic insights into TRP channel function in a native system–photoreceptor cells. Using a combination of electrophysiology (field recordings), cell biology, and molecular modeling, we have revealed roles of key motifs for activation, inactivation and protein folding of TRP in vivo.     

近视性豹纹状眼底改变的影像及功能学评估进展

近视已成为全球性视觉损伤及致盲的严重负担,世界卫生组织已经将近视的防治列入全球防盲计划之中。随着近视病程进展,会出现多种眼部病理性改变,从而导致视力损害,严重者甚至致盲。目前,近视患病率有增加和年轻化趋势,病理性近视导致的社会问题也日益受到重视。其中豹纹状眼底是近视性眼底病变自然病程的最早期病变,也是视网膜病变发展的一个重要临床标志。目前,有几种不同的豹纹状眼底分级方法,均是通过眼底彩照进行主观分级。通过检眼镜、眼底照相、光学相干断层扫描、视网膜电图及微视野等模式影像可联合观察豹纹状眼底的形态学特征和功能状况。本文将综述豹纹状眼底的影像学特征及常见应用,以期对眼科临床提供相关参考。     

模拟失重对成年小鼠闪光视网膜电图和视网膜微循环的影响

目的:小鼠通过悬尾来模拟失重状态下体液头向重分布,然后观察视网膜电图(ERG)和视网膜微循环的变化。方法:正常成年雄性C57BL/6J小鼠随机分到3个实验组和3个对照组,最终每组6只。具体分组如下:实验1组(尾悬15d),实验2组(尾悬30d),实验3组(悬吊30d后恢复体位30d);对照1组(正常饲养15d),对照2组(正常饲养30d),对照3组(正常饲养60d)。时间满足后马上检测暗适应闪光ERG,记录混合反应和振荡电位(OPs),并进行荧光素眼底血管造影(FFA)。然后提取视网膜组织,用免疫组化法检测感光细胞视色素或视蛋白的表达,用TUNEL试剂盒检测视网膜组织细胞的凋亡情况。结果:悬吊15d组,暗适应ERG的混合反应,b波较大而OPs振幅明显降低,后者第二个子波(O 2)幅值197±33μV,15d未悬吊组336±47μV(t=-5.938,P<0.001)。悬吊30d组,小鼠ERG恢复,O 2幅值264±39μV,与30d未悬吊组308±41μV无差异(t=-1.887,P>0.05)。悬吊15d组FFA,视网膜微血管较对照组更密集,呈迂曲扩张的表现,其他实验组基本正常。各实验组感光细胞视色素或视蛋白的表达未见明显异常,视网膜未见凋亡阳性细胞。结论:模拟失重状态下体液头向重分布,短期内小鼠ERG和视网膜微循环可能受到影响,但未对视网膜产生明显的永久性损伤。