视网膜黄斑部解剖特点及病变患者的表现

黄斑负责中心视力.它对日常生活起着重要作用,对于物体的颜色、精细形态、距离及运动速度等的判断都要借助于黄斑,在多种疾病的眼底检查中起着重要作用,而且黄斑结构上有异于其余地区视网膜,所以特此对黄斑及其作用进行简要综述.     

复方三芪提取物对NMDA致大鼠视网膜损伤的保护作用

目的:研究复方三芪提取物对由N-甲基-D天门冬氨酸(NMDA)诱导的大鼠视网膜损伤模型的保护作用.方法:20只SD大鼠随机分为5组:正常对照组、模型组、复方三芪提取物低、中、高剂量组.模型组和给药组大鼠于右眼玻璃体内注射2μL 40 nmol.L-1NMDA,制备视网膜神经元损伤模型.给药组在NMDA注射前7 d起给予复方三芪提取物灌胃(3.903,7.805,15.61 g.kg-1.B.W.);正常对照组和模型组则给予等剂量的生理盐水灌胃.注射NMDA 7 d后静脉取血,测定血清超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量,取眼球组织,切片HE染色,观察视网膜厚度,并对视网膜视神经节细胞层(RGCL)神经元进行计数.结果:模型组大鼠RGCL神经元个数为正常组大鼠的51±6%.同模型组相比,复方三芪提取物(3.903,7.805,15.61 g.kg-1.B.W.)能剂量依赖性地增加RGCL神经元个数(P<0.05),依次为正常组的69±6%,89±7%,103±7%.复方三芪提取物(7.805 g.kg-1.B.W.)显著提高大鼠血清SOD活性并降低MDA含量(P<0.001).结论:复方三芪提取物能抑制NMDA诱导的视网膜脂质过氧化,并能阻止大鼠视网膜神经元进行性丢失,对NMDA诱导损伤的大鼠视网膜有修复作用.提示复方三芪提取物可能具有促进神经元的再生作用.     

Representing the retinal line spread shape with mathematical functions

Objective： To report a mathematical function that characterizes the double-pass line spread function （LSF） of the human eye. Determining analytical functions that represent the double-pass LSF is important because it allows modeling the optical performance of the eye, Methods： Optical section retinal images, generated in normal human eyes using a modified slit-lamp biomicroscope, were analyzed to derive the double-pass LSF by plotting the intensity distribution of laser light reflected/ scattered from the vitreoretinal interface. Three mathematical functions （Lorentzian, Gaussian, exponential） were fitted to the double-pass LSF and the root mean square error （RMSE） was calculated to provide a measure of the goodness of fit. Results： The Lorentzian function provided the best representation of the double-pass LSF of normal human eyes. The full width at half maximum （FWHM） of the Lorentzian fitted curve was positively correlated with age, indicating that the double-pass LSF broadens with age. Furthermore, the goodness of fit of the Lorentzian function was significantly better in younger subjects as compared with older subjects, suggesting that the fitted function to the double-pass LSF may vary according to age. Conclusion： The results demonstrate an age-related change in the double-pass LSF width and the goodness of fit of the Lorentzian function.     

真鲷视网膜和视网膜运动反应的发育

真鲷仔鱼视网膜在孵后３ｄ功能化，变态以前，仔鱼眼睛为纯视锥视网膜，孵后２８ｄ，视杆细胞出现，单锥细胞开始融合为双锥细胞，同时，暗适应条件下的色素指数明显下降，视网膜运动反应出现，当发育到４６ｄ视网膜中单锥细胞和双锥细胞的排列已呈方形镶嵌，视锥细胞密度由３ｄ时的４４个／１００μｍ降为４６ｄ的１９个／１００μｍ，眼睛的焦距由３ｄ时的０．０５７ｍｍ增加到４６ｄ的０．６０ｍｍ，代表视敏度的最小分辨角由３ｄ     

中西医结合治疗中心性视网膜脉络膜炎

本文用祖国医学的观点阐述了中心性视网膜脉络膜炎的病理,讨论了治疗方案。采用中西医结合的方法进行治疗,其有效率达90%。     

The use of iodinated density gradient media for the isolation of rod outer segments

Summary Sucrose, nycodenz, metrizamide and a mixture of equal volumes of sucrose and metrizamide were used as density gradient media for the isolation of retinal rod outer segments. The high osmolarity of sucrose had a strongly negative effect on the nature of the rod outer segments, whereas they were much better preserved using iodinated density gradient media such as nycodenz and metrizamide for their isolation.     

The unique substrate specificity of human AOC2, a semicarbazide-sensitive amine oxidase

Semicarbazide-sensitive amine oxidases (SSAOs) catalyze oxidative deamination of primary amines, but the true physiological function of these enzymes is still poorly understood. Here, we have studied the functional and structural characteristics of a human cell-surface SSAO, AOC2, which is homologous to the better characterized family member, AOC3. The preferred in vitro substrates of AOC2 were found to be 2-phenylethylamine, tryptamine and p-tyramine instead of methylamine and benzylamine, the favored substrates of AOC3. Molecular modeling suggested structural differences between AOC2 and AOC3, which provide AOC2 with the capability to use the larger monoamines as substrates. Even though AOC2 mRNA was expressed in many tissues, the only tissues with detectable AOC2-like enzyme activity were found in the eye. Characterization of AOC2 will help in evaluating the contribution of this enzyme to the pathological processes attributed to the SSAO activity and in designing specific inhibitors for the individual members of the SSAO family. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

石鸡、灰椋鸟和家鸽视网膜结构的比较

对石鸡（Alectoris chukar）、灰椋鸟（Sturnus cineraceus）、家鸽（Columbiformes）的正常视网膜结构进行了形态学观察,且对其视网膜各层的厚度、各核层胞核的层数、大小、核的直径做了比较分析,结果表明：三种鸟类视网膜和其他脊椎动物一样,均为10层,石鸡、家鸽视网膜结构相似,为昼行性动物视网膜结构特征,灰椋鸟为晨昏性视网膜结构特征.说明结构的差异性与其生活习性的不同相一致.     

Short axon ganglion cells in the chick retina

Summary Using Golgi's staining technique, we investigated some ganglion cells whose axons do not project out of the retina area. These axons, after following a short trajectory through the optic nerve fiber layer or through the 5th stratum of the inner plexiform layer (IPL), change their direction and end in the inner stratum of the IPL.