白内障患者晶状体上皮细胞中Fas蛋白的表达

目的:了解不同类型白内障患者晶状体上皮细胞(lens epi-thelial cell,LECs)的凋亡情况及其与Fas蛋白(CD95)的关系。方法:取年龄相关性白内障、糖尿病性白内障及高度近视并发性白内障患者超声乳化手术中取下的前囊膜标本共73例。应用光镜、透射电镜及TUNEL标记法观察LECs的凋亡情况。同时应用免疫组化和流式细胞分别定性、定量检测Fas蛋白(CD95)在LECs中的表达。结果:光镜下3种白内障患者的LECs都呈透明样变性,细胞内有空泡。电镜下可见正常以及变性、坏死的LECs。部分LECs细胞内染色质凝集并边缘化,呈早期细胞凋亡改变。TUNEL检测发现3种白内障患者的LECs中均有TUNEL阳性细胞存在,LECs的凋亡率分别为(32.20±7.91)%、(31.00±9.43)%、(28.20±8.04)%,3种白内障间未见统计学差异。免疫组化结果表明在3种白内障患者的LECs中均有Fas蛋白(CD95)表达。流式细胞定量检测年龄相关性、糖尿病性及高度近视并发性白内障患者LECs中Fas蛋白(CD95)的表达量分别为(65.72±9.95)%、(63.46±13.30)%、(31.46±17.25)%,高度近视并发性白内障LECs中Fas蛋白(CD95)的表达与其他两种白内障间存在统计学差异(t检验,P<0.05)。结论:年龄相关性白内障、糖尿病性白内障及高度近视并发性白内障患者的LECs均出现凋亡,LECs的凋亡很可能是非先天性白内障发病的细胞病理学基础。Fas蛋白(CD95)介导的LECs的凋亡在年龄相关性白内障及糖尿病性白内障的形成中起重要的作用,而在高度近视并发性白内障LECs凋亡中可能存在其他通路。     

P53基因及P53蛋白与人晶状体上皮细胞的增殖和凋亡的关系

目的 研究抑癌基因P53及其表达产物P53蛋白在不同年龄组的晶状体上皮细胞(LECs)中的表达与晶状体上皮细胞凋亡和增殖的关系。方法 收集手术切除的不同年龄组的晶状体前囊膜或晶状体标本42例,应用链霉菌亲生物素蛋白-过氧化物酶免疫组织化学染色测定P53蛋白和细胞增殖核抗原的表达;应用DNA末端转移酶介导的Bio-duTP原位末端标记技术作凋亡细胞的定量检测;应用核酸分子原位杂交法检测P53 mRNA的表达,并分别定义凋亡指数和增殖指数。结果 (1)正常胚胎组LECs中P53蛋白阳性率<0.01％,在儿童白内障组和老年白内障组的LECs中其阳性表达率分别为1.21％~3.25％和12.83％~19.15％,两组之间有显著性差异(P<0.01)。(2)正常胚胎组和儿童白内障组的LECs中PCNA的表达显著高于老年白内障组(P<0.01)。(3)正常胚胎组的LECs中几乎未见凋亡细胞,老年白内障组的LECs中凋亡细胞阳性检出率为26.16％~27.80％,显著高于儿童组的1.52％-3.36％(P<0.01)。(4)正常胚胎组的LECs中P53mRNA阳性表达率<0.01％,老年白内障组阳性表达率为18.44％~20.10％,明显高于儿童白内障组的2.89％-5.05％(P<0.01)。(5)人LECs中凋亡指数AI和增殖指数PI之间无明显相关性,P53蛋白与AI呈显著正相关(γ=0.900,P<0.01),与PI呈显著负相关(γ=-0.807,P<0.01)。     

剥脱综合征晶状体上皮细胞凋亡与增生特性的研究

目的 探讨剥脱综合征眼中剥脱碎屑来源以及剥脱综合征性白内障与晶状体上皮细胞凋亡的关系.方法 应用免疫组织化学SP法检测Caspase-3、 c-fos、c-jun在剥脱综合征性白内障以及单纯老年性白内障(各15例)晶状体上皮细胞中的表达.结果 Caspase-3、 c-fos、c-jun 在剥脱综合征性白内障晶状体上皮细胞中的表达呈强阳性分别为15例、10例、15例,c-fos表达阳性5例;在单纯老年性白内障晶状体上皮细胞中的表达呈强阳性分别为4例、8例、11例;表达阳性为11例、7例、4例.结论 剥脱综合征性白内障与老年性白内障相同也与晶状体上皮细胞凋亡有关,同时剥脱综合征眼中剥脱碎屑的来源可能也与晶状体上皮细胞凋亡和增生特性相关.     

白内障手术摘出前囊下晶状体上皮细胞中β1整联蛋白、Fas蛋白的表达

目的了解糖尿病性白内障及并发性(高度近视)白内障晶状体上皮细胞(LECs)中β1整联蛋白与Fas蛋白的表达情况,以探讨其与LECs凋亡的关系。方法应用免疫组化、流式细胞仪和共聚焦显微镜对52例白内障手术患者术中取出的前囊下LECs分别定性、定量及定位检测β1整联蛋白和Fas蛋白的表达。结果糖尿病性及并发性(高度近视)白内障患者免疫组化结果表明在其LECs中均有β1整联蛋白、Fas蛋白表达;流式细胞定量检测其LECs中β1整联蛋白的表达量分别为68.41±16.98%、39.22±21.18%,Fas蛋白的表达量分别为63.46±13.30%、31.46±17.25%。LECs中β1整联蛋白、Fas蛋白的表达在两种白内障间存在统计学差异(P<0.05)。β1整联蛋白与Fas蛋白在LECs中的表达具有正相关性。共聚焦显微镜观察发现β1整联蛋白与Fas蛋白大部分共同定位于LECs的细胞膜上。结论Fas蛋白介导的LECs的凋亡在糖尿病性白内障的形成中起重要的作用,而在并发性(高度近视)白内障LECs凋亡中可能存在其他通路。β1整联蛋白的作用很可能是一种促进LECs凋亡的蛋白,它与Fas蛋白一起促进LECs凋亡。     

SIRT1基因在糖尿病性白内障患者晶状体上皮细胞表达的初步研究

目的:探讨SIRT1基因在糖尿病性白内障晶状体上皮细胞的表达.方法:选取2012-01/2014-10来我院治疗的糖尿病性白内障患者、年龄相关性白内障患者和外伤性白内障患者各20例,采用RT-PCR法检测各组患者晶状体上皮细胞中SIRT1基因含量,Western blot法检测晶状体上皮细胞中SIRT1蛋白含量,TUNEL法检测晶状体上皮细胞的凋亡率.结果:RT-PCR检测结果显示,外伤性白内障患者组SIRT1 mRNA相对含量最高为1.000±0.078,其次为年龄相关性白内障患者组为0.427±0.067,糖尿病性白内障组为0.389±0.112,与外伤性白内障组比较,差异有统计学意义(P＜0.05);Western blot检测显示,外伤性白内障患者晶状体上皮细胞中SIRT1蛋白的表达量最高,其次是年龄相关性白内障组,糖尿病性白内障组SIRT1蛋白的表达量最低;TUNEL法检测结果显示,外伤性白内障组和年龄相关性白内障组患者LECs细胞凋亡率分别为(4.5±2.3)％和(8.7±4.1)％,差异无统计学意义;而糖尿病性白内障组LECs凋亡率为(24.3±6.1)％,与外伤性白内障组及年龄相关性白内障组比较差异有统计学意义(P＜0.05).结论:糖尿病性白内障患者晶体上皮细胞中SIRT1基因及蛋白表达下降,提示该基因参与了糖尿病性白内障的发生,这为我们今后进一步的研究提供了可靠的理论依据.探索调节SIRT1基因在晶状体上皮细胞中表达的有效途径,将为糖尿病性白内障的早期干预治疗提供新的思路.     

不同类型年龄相关性白内障晶状体上皮细胞衰老标记蛋白30的表达及与细胞凋亡的关系

背景 随着人口的老龄化,白内障的发病率逐年上升,研究表明,衰老标记蛋白30( SMP-30)与白内障的发生发展关系密切. 目的 了解不同类型白内障晶状体上皮细胞( LECs)中SMP-30的表达及LECs的凋亡情况,探讨不同类型年龄相关性白内障的发病机制. 方法 收集2010年3-10月在武汉大学中南医院眼科行白内障超声乳化摘出术的年龄相关性皮质性白内障59例80眼和核性白内障53例70眼,2个组患者年龄匹配(P＞0.05).白内障手术中环形撕取晶状体前囊膜,应用免疫组织化学法和实时荧光定量聚合酶链反应( real-time PCR)技术分别定性、定量检测SMP-30蛋白及其mRNA在2个组白内障LECs中的表达.用TUNEL标记法观察LECs的凋亡情况,对比分析两种类型白内障晶状体前囊膜中SMP-30的表达及细胞凋亡的差异.结果 免疫组织化学法检测表明,SMP-30主要表达于晶状体囊膜的细胞质中,在晶状体囊膜中央部表达较弱,越近周边表达越强,差异均有统计学意义(核性:45.21±2.79 vs 76.42±11.21,P=0.042;皮质性:108.32±4.32 vs 206.34±15.67,P=0.037).核性白内障LECs中SMP-30 mRNA的表达少于皮质性,差异有统计学意义(60.02±9.08 vs 157.33±13.01,P=0.034).TUNEL染色显示,2个组白内障LECs凋亡百分率中央部明显高于周边部,差异均有统计学意义(核性:19.34％±0.11％vs 8.32％±0.57％,P=0.025;皮质性:42.07％±0.86％vs 13.55％±0.64％,P=0.010),细胞凋亡百分率低于皮质性,差异有统计学意义(14.05％±0.22％vs 27.70％±0.81％,P=0.007). 结论 两种类型年龄相关性白内障的发生均与LECs凋亡有关,SMP-30的表达与其密切相关.     

c—myc反义寡核苷酸抑制半乳糖性白内障晶状体上皮细胞凋亡的机制

目的研究c-myc反义寡核苷酸（ASODN）对半乳糖性白内障晶状体上皮细胞（LECs）凋亡的影响。方法将Wistar大鼠按随机数字表法分为生理盐水组、半乳糖组和半乳糖＋c-myc ASODN组,每组36只。半乳糖组及半乳糖＋c—mycASODN组每日球后注射O．2mL20％半乳糖,制作大鼠半乳糖性白内障模型,半乳糖＋c—mycASODN组球后注射半乳糖4h后加注Lipo—mycASODN复合液0．2mL,隔日1次。分别于给药后7、14、24d处死动物,取出晶状体,检测LECs的凋亡情况,采用TUNEL法检测c—mycASODN对半乳糖诱导LECs凋亡的影响,透射电镜下观察LECs超微结构的改变。结果各组在7、14、24d的LECs凋亡率比较,差异均有统计学意义（F7 days=3418．495,P〈0．01;F14 days=1137．555,P〈0．01;F14 days=2198．871,P〈0．01）;24d时半乳糖组LECs的凋亡率为56．57±3．20,生理盐水组为0．37±0．11,差异有统计学意义（P〈0．01）;半乳糖＋c．mycASODN组细胞凋亡率为29．35±1．63,较半乳糖组明显降低（P〈0．05）。透射电镜下观察发现,半乳糖组可见LECs呈凋亡细胞的早期改变;随着高糖诱导时间的延长,凋亡细胞逐渐增多;生理盐水组几乎未见到凋亡细胞;半乳糖＋c—mycASODN组凋亡细胞数量较同期半乳糖组少。结论在白内障形成过程中半乳糖能诱导LECs凋亡,c．mycASODN能够抑制半乳糖诱导的LECs凋亡。     

年龄相关性白内障晶状体上皮细胞的Smac、caspase-3表达及死亡方式

目的探讨年龄相关性白内障晶状体上皮细胞（LECs）中Smac、caspase-3的表达和LECs超微结构变化及死亡方式。方法收集皮质性（30例）、核性（24例）、后囊下性（28例）年龄相关性白内障患者晶状体前囊片,以12例高度近视摘出的透明晶状体的晶状体前囊片为对照,应用免疫组织化学链酶菌抗生素蛋白-过氧化物酶法检测Smac、caspase-3蛋白在LECs中的表达,并采用透射电镜观察LECs超微结构的改变及死亡方式。结果Smac、caspase-3蛋白在年龄相关性白内障组LECs中的阳性表达率分别为81.71%、78.05%,与透明晶状体组比较染色阳性率及染色强度差异均有统计学意义（P〈0.05）。3种类型年龄相关性白内障透射电镜下均可见LECs多表现为肿胀,线粒体嵴缺失、空泡变、髓样化,粗面内质网扩张、颗粒融合和脱颗粒现象,仅1例核性白内障中可见到核膜皱缩向外呈锐角凸起,部分双层核膜融合,模糊不清,细胞核内染色质浓缩,未见凋亡小体。结论Smac、caspase-3蛋白可能参与了年龄相关性白内障的形成。年龄相关性白内障LECs存在凋亡、胀亡等多种细胞死亡方式,细胞凋亡与细胞胀亡的发生可能存在部分分子机制的重叠。LECs超微结构的改变表明线粒体形态改变和功能异常在年龄相关性白内障发生中起重要作用。     

P53和bcl-2在老年性白内障晶体上皮细胞中蛋白表达的研究

目的：研究P53，Bcl-2基因在老年性白内障晶体上皮细胞中的蛋白表达。探讨P53，bcl-2在老年性白内障晶体上皮细胞凋亡中的作用。方法：应用免疫组织化学方法，对30例老年性白内障及10例正常透明晶体上皮细胞进行P53，bcl-2基因蛋白表达的检测，计算P53，bcl-2基因蛋白表达阳性细胞百分率。结果：P53在正常晶体上皮细胞中无蛋白表达，在老年性白内障晶体上皮细胞中蛋白表达率为16.9-19.1%,bcl-2在两组中均无蛋白表达。结论：P53在老年性白内障晶体上皮细胞中蛋白高表达，P53可能促进了老年性白内障中晶体上皮细胞的凋亡。     

人及小鼠白内障晶状体上皮细胞凋亡的超微结构

目的 探讨人老年性白内障及小鼠先天性白内障与其晶状体上皮细胞凋亡的关系。方法 用透射电镜观察４例老年性白内障患者及２例先天性白内障小鼠晶状体上皮细胞凋亡的超微结构,并分别与同类正常晶状体上皮细胞超微结构进行比较。结果 老年性白内障患者及先天性白内障小鼠晶状体上皮细胞中均可见凋亡细胞,而正常晶状体未见凋亡细胞。结论 人老年性白内障及小鼠先天性白内障的发生均与其晶体上皮细胞的凋亡有关。     

Paraneoplastic and non-paraneoplastic retinopathy and optic neuropathy: Evaluation and management

Paraneoplastic syndromes involving the visual system are a heterogeneous group of disorders occurring in the setting of systemic malignancy. Timely recognition of one of these entities can facilitate early detection and treatment of an unsuspected, underlying malignancy, sometimes months before it would have otherwise presented, and gives the patient an increased chance at survival. We outline the clinical features, pathogenesis, and treatment strategies for the retinal- and optic nerve–based paraneoplastic syndromes: cancer-associated retinopathy; melanoma-associated retinopathy; paraneoplastic vitelliform maculopathy; bilateral diffuse uveal melanocytic proliferation; paraneoplastic optic neuropathy; and polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome. Distinguishing these disorders from their non-paraneoplastic counterparts (e.g., autoimmune-related retinopathy and optic neuropathy, and acute zonal occult outer retinopathy) and determining appropriate systemic evaluation for the responsible tumor can be challenging. In addition, we discuss the utility and interpretation of autoantibody testing.     

Segmentation and accuracy in copying and drawing: Experts and beginners

As part of an ongoing investigation into real-world copying and drawing, I recorded the eye-hand drawing strategies of 16 subjects with drawing experiences ranging from expert to novice while they copied a line drawing of a standing nude. The experts produced accurate copies whereas all the beginners produced marked inaccuracies of overall scaling, proportion and shape. Analysis of eye and hand movements showed that the experts alone segmented the original drawing into simple line sections that were copied one at a time using a direct eye-hand strategy not requiring intermediary encoding to visual memory. The results suggest that segmentation into simple lines defines the task-specific process of accurate copying, and that this process is restricted to experts, i.e. acquired through training and practice. Additional preliminary tests also suggest that a similar process may apply to drawing a model from life.     

Nodes and nodal points and lines in eyes and other optical systems

The typical stigmatic optical system has two nodal points: an incident nodal point and an emergent nodal point. A ray through the incident nodal point emerges from the system through the emergent nodal point with its direction unchanged. In the presence of astigmatism nodal points are not possible in most cases. Instead there are structures, called nodes in this paper, of which nodal points are special cases. Because of astigmatism most eyes do not have nodal points a fact with obvious implications for concepts, such as the visual axis, which are based on nodal points. In order to gain insight into the issues this paper develops a general theory of nodes which holds for optical systems in general, including eyes, and makes particular allowance for astigmatism and relative decentration of refracting elements in the system. Key concepts are the incident and emergent nodal characteristics of the optical system. They are represented by 2 × 2 matrices whose eigenstructures define the nature and longitudinal position of the nodes. If a system's nodal characteristic is a scalar matrix then the node is a nodal point. Otherwise there are several possibilities: Firstly, a node may take the form of a single nodal line. Second, a node may consist of two separated nodal lines reminiscent of the familiar interval of Sturm although the nodal lines are not necessarily orthogonal. Third, a node may have no obvious nodal line or point. In the second and third of these classes one can define mid-nodal ellipses. Astigmatic systems exist with nodal points and stigmatic systems exist with no nodal points. The nodal centre may serve as an approximation for a nodal point if the node is not a point. Examples in the Appendix , including a model eye, illustrate the several possibilities.     

Sensitivity to first- and second-order motion and form in children and adults

We compared the sensitivity of adults and children aged 3-10 years to first- and second-order motion and form. For first-order stimuli, at all ages sensitivity was better for motion than form, and motion thresholds were better at 6 Hz than at 1.5 Hz. For second-order stimuli, at all ages sensitivity was better for form than motion, and motion thresholds were better at 0.25 cyc/deg than at 1 cyc/deg. Thresholds became adult-like later for motion than for form and later for first-order than second-order stimuli. For first-order stimuli, the changes with age were larger and more protracted.     

Ethics and optometry: concepts and applications

Ethics refers both to the study of behaviour, and moral principals. The related concepts of justice and law are also relevant to optometry. A profession typically claims specialist knowledge and ethical behaviour – putting the interests of clients above its own. However, professional codes fail as ethical directives, and their goals are questioned. Beginning with broad principles, institutional ethics and issues of general health care provision are considered, and applications to optometry are made. Ethical theory can guide us in interacting with our patients, utilising resources and ordering priorities. The conservative approach to consumerism and advertising is defended on the basis of protecting public and professional interests. Ethical behaviour can be fostered, and this process should begin in undergraduate education.     

Nutritional antioxidants and age-related cataract and maculopathy

Loss of vision is the second greatest, next to death, fear among the elderly. Age-related cataract (ARC) and maculopathy (ARM) are two major causes of blindness worldwide. There are several important reasons to study relationships between risk for ARC/ARM and nutrition: (1) because it is likely that the same nutritional practices that are associated with prolonged eye function will also be associated with delayed age-related compromises to other organs, and perhaps, aging in general, (2) surgical resources are insufficient to provide economic and safe surgeries for cataract and do not provide a cure for ARM, and (3) there will be considerable financial savings and improvements in quality of life if health rather than old age is extended, particularly given the rapidly growing elderly segment of our population. It is clear that oxidative stress is associated with compromises to the lens and retina. Recent literature indicates that antioxidants may ameliorate the risk for ARC and ARM. Given the association between oxidative damage and age-related eye debilities, it is not surprising that over 70 studies have attempted to relate antioxidant intake to risk for ARC and ARM. This article will review epidemiological literature about ARC and ARM with emphasis on roles for vitamins C and E and carotenoids. Since glycation and glycoxidation are major molecular insults which involve an oxidative stress component, we also review new literature that relates dietary carbohydrate intake to risk for ARC and ARM. To evaluate dietary effects as a whole, several studies have tried to relate dietary patterns to risk for ARC. We will also give some attention to this emerging research. While data from the observational studies generally support a protective role for antioxidants in foods or supplements, results from intervention trials are less encouraging with respect to limiting risk for ARC/ARM prevalence or progress through antioxidant supplementations, or maintaining higher levels of antioxidants either in diet or blood. Without more information it is difficult to parse these results. It would be worthwhile to determine why the various types of studies are not yielding similar results. However, there are many common insults and mechanistic compromises that are associated with aging, and proper nutrition early in life may address some of these compromises and provide for extended youthful function later in life. Indeed, proper nutrition, possibly including use of antioxidant supplements for the nutritionally impoverished, along with healthy life styles may provide the least costly and most practical means to delay ARC and ARM. Further studies should be devoted to identifying the most effective strategy to prevent or delay the development and progress of ARC/ARM. The efforts should include identifying the right nutrient(s), defining useful levels of the nutrient(s), and determining the age when the supplementation should begin.     

Exogenous attention and color perception: performance and appearance of saturation and hue

Exogenous covert attention is an automatic, transient form of attention that can be triggered by sudden changes in the periphery. Here we test for the effects of attention on color perception. We used the methodology developed by Carrasco, Ling, and Read [Carrasco, M., Ling, S., & Read, S. (2004). Attention alters appearance. Nature Neuroscience, 7 (3) 308-313] to explore the effects of exogenous attention on appearance of saturation (Experiment 1) and of hue (Experiment 2). We also tested orientation discrimination performance for single stimuli defined by saturation or hue (Experiment 3). The results indicate that attention increases apparent saturation, but does not change apparent hue, notwithstanding the fact that it improves orientation discrimination for both saturation and hue stimuli.     

Clinical and experimental links between diabetes and glaucoma

Glaucoma is a leading cause of blindness. It is a multifactorial condition, the risk factors for which are increasingly well defined from large‐scale epidemiological studies. One risk factor that remains controversial is the presence of diabetes. It has been proposed that diabetic eyes are at greater risk of injury from external stressors, such as elevated intraocular pressure. Alternatively, diabetes may cause ganglion cell loss, which becomes additive to a glaucomatous ganglion cell injury. Several clinical trials have considered whether a link exists between diabetes and glaucoma. In this review, we outline these studies and consider the causes for their lack of concordant findings. We also review the biochemical and cellular similarities between the two conditions. Moreover, we review the available literature that attempts to answer the question of whether the presence of diabetes increases the risk of developing glaucoma. At present, laboratory studies provide robust evidence for an association between diabetes and glaucoma.