IL-1ra和CsA对大鼠角膜移植物TRAIL及DR4表达的影响

目的 比较研究白细胞介素-1受体拮抗剂(IL-1ra)和环孢素A(CsA)对急性排斥期角膜移植物肿瘤坏死因子相关凋亡诱导配体(TRAIL)及其死亡受体4(DR4)表达的影响.方法 建立大鼠同种异体穿透角膜移植模型,设生理盐水处理组、CsA治疗组和IL-1ra治疗组.免疫组织化学法检测急性排斥期角膜植片TRAIL及DR4的表达,并以正常大鼠角膜作为对照.结果 TRAIL及DR4在正常角膜中均有表达,主要分布于上皮层,基质层及内皮层有少量表达.急性排斥期角膜植片各层TRAIL及DR4表达均增高;与正常大鼠相比,生理盐水组TRAIL及DR4蛋白表达增高最为明显,CsA组次之,IL-1ra组TRAIL及DR4蛋白表达轻度增高.结论 IL-1ra、CsA均可通过调节TRAIL及DR4的表达抑制角膜移植排斥反应,且IL-1ra的效果优于CsA.     

共刺激分子Tim-1在角膜移植排斥反应中的作用

背景 角膜移植是目前临床上治疗角膜盲可靠且有效的复明手段,角膜移植术后的免疫排斥反应是角膜移植失败的主要原因. 目的 研究共刺激分子Tim-1在大鼠角膜组织中的表达及其在角膜移植排斥反应发生和发展过程中的作用.方法 40只清洁级成年雌性Wistar大鼠随机分为正常对照组、自体角膜移植组和同种异体角膜移植组.正常对照组大鼠未行任何手术,自体角膜移植组分别以Wistar大鼠作为供体和受体施行穿透角膜移植术,而同种异体角膜移植组以SD大鼠角膜作为供体,Wistar大鼠作为受体行穿透角膜移植术,各组供体角膜植片均为3.5mm,植床直径为3.0 mm.分别于术后7d、14d在裂隙灯显微镜下观察术眼角膜炎症反应情况,按照Larkin的标准进行排斥反应评分,计算排斥反应指数（RI）,观察各组角膜植片的平均存活时间和植片存活率.术后7d、14d,3个组各取3只大鼠眼球制备角膜组织切片,分别行组织病理学检查和免疫组织化学检测,观察角膜组织的炎症反应和共刺激分子Tim-1蛋白在角膜组织中的表达;此外分别于术后7d、14d各组取5只大鼠角膜制备组织匀浆,采用实时荧光定量PCR法检测共刺激分子Tim-1 mRNA在大鼠角膜植片中表达量（吸光度,A）的变化.结果 术后7d,自体角膜移植组和同种异体角膜移植组大鼠角膜植片均出现轻度水肿;术后14 d,自体角膜移植组角膜植片水肿消失,植片透明,而同种异体角膜移植组大鼠角膜植片水肿增厚,呈灰白色混浊,可见新生血管形成.自体角膜移植组植片的存活率为100％,同种异体角膜移植组植片存活率为0,平均生存时间为（9.8±1.2）d.组织病理学检查表明,术后7d自体角膜移植组植片基质层可见炎性细胞浸润,但术后14d炎性细胞明显减少;同种异体角膜移植组术后7d植片水肿,基质层可见炎性细胞浸润,术后14 d阳性细胞大量增加,可见新生血管.免疫?     

白细胞介素1受体拮抗剂对急性排斥期大鼠角膜移植物Fas/FasL表达的影响

目的 研究白细胞介素-1受体拮抗剂(IL-1 ra)对急性排斥反应期角膜移植物Fas／FasL蛋白表达的影响。方法 建立大鼠同种异体穿透角膜移植模型，设生理盐水组和IL-1 ra治疗组。急性排斥期随机取角膜植片，用免疫组织化学(SABC)法检测植片Fas／FasL蛋白表达。并以正常大鼠角膜作对照。结果 在正常角膜，Fas和FasL蛋白主要表达于上皮层及内皮层；基质层中仅有少量Fas蛋白表达，未见FasL蛋白表达。急性排斥期角膜植片全层Fas和FasL蛋白表达增高，且植片周边(距伤口边缘0．5mm范围内)增高显著；IL-1 ra治疗组Fas和FasL蛋白表达均低于生理盐水组。结论 IL-1 ra可通过调节Fas／FasL蛋白的表达抑制角膜移植免疫排斥反应的发生。     

核因子-κB在大鼠角膜移植排斥反应中的表达

目的了解核因子-κB(NF-κB)在大鼠同种异体角膜移植排斥反应中的表达,探讨其在角膜移植免疫排斥反应中的作用。方法在异体大鼠间建立角膜移植动物模型。免疫组化法检测移植后不同时间段NF-κB在角膜不同组织层次的表达;免疫印迹法检测移植后NF-κB蛋白在角膜中的表达。结果免疫组化显示:正常大鼠仅角膜上皮及内皮层表达NF-κB:异体移植组术后3d角膜上皮及基质层NF-κB表达增高,5～7d呈强阳性,后逐渐减弱。免疫印迹提示:正常大鼠角膜未见明显NF-κB蛋白表达;异体移植组术后1d即可检测出NF-κB表达,随时间推移其蛋白量逐渐增加,5～7d达高峰,10d后下降,14d接近正常水平。自体移植组7d所检测到NF-κB的表达较异体移植组明显减弱。结论NF-κB在角膜移植中的表达,可能与角膜移植免疫排斥反应有关。     

可诱导的共刺激分子在大鼠角膜中的表达

目的 探讨可诱导的共刺激分子(ICOS)在大鼠角膜移植排斥反应中角膜上的表达和意义.方法 采用逆转录-聚合酶链反应(RT-PCR)、蛋白免疫印迹分析检测大鼠角膜移植后角膜中ICOS mRNA和蛋白的表达;免疫组织化学方法 检测ICOS蛋白在角膜中的表达部位.结果 ICOS在正常的角膜中无表达;同种异体角膜移植组术后角膜中的ICOS mRNA转录及蛋白的表达从第1 d起即呈明显上升趋势,第7 d达高峰;免疫组织化学显示同种异体角膜移植术后ICOS阳性表达见于角膜基质层浸润的淋巴细胞.结论 同种异体角膜移植术后ICOS在角膜中表达较对照组明显升高,可能在同种异体角膜术后的免疫排斥反应中起重要作用.     

免疫赦免在小鼠角膜移植排斥中的作用研究

目的:阐明同种异体小鼠角膜移植术后免疫排斥反应及免疫赦免的相关性。方法:建立小鼠原位角膜移植及同种异体小鼠角膜移植实验模型。观察原位移植与同种异体移植术后角膜植片发生排斥的情况,对比两种移植术后植片的存活率,了解小鼠角膜移植术后发生排斥反应与免疫赦免反应之间的关系。结果:小鼠原位角膜移植术后植片100%存活;同种异体小鼠角膜移植术后存活率为25%。结论:小鼠角膜移植术后免疫排斥并非绝对,免疫赦免在角膜移植术中发挥重要作用。     

ICOS共刺激通路参与角膜移植免疫排斥反应的研究

目的研究可诱导共刺激分子（ICOS）共刺激通路与角膜移植急性免疫排斥反应的关系。方法建立大鼠同种异体穿透角膜移植模型,分别于术后7d、14d取植片进行病理学观察,采用RT-PCR法检测植片组织ICOS mRNA的表达情况,免疫组织化学法检测植片组织淋巴细胞ICOS蛋白水平;同时采用流式细胞术检测外周血CD3^＋ICOS^＋T／CD3^＋T的表达情况。均以正常大鼠作为正常对照。结果正常大鼠角膜组织未检测到ICOS蛋白及ICOS mRNA的表达,移植术后植片组织可以检测到ICOS蛋白及ICOS mRNA的表达,且术后14d高于术后7d（P=0．000）;与正常大鼠外周血CD3^＋ICOS^＋T／CD3^＋T的表达相比术后表达皆升高（方差齐性,P=0．156）,且术后14d外周血CD3^＋ICOS^＋T／CD3^＋T的表达高于术后7d的表达（P=0．000）。结论共刺激分子ICOS与角膜移植急性免疫排斥反应密切相关。     

CD86在排斥反应和前房相关免疫偏离过程中的作用

目的检测大鼠角膜共刺激分子CD86（B7—2）的原位表达,探讨CD86分子与角膜移植排斥反应和前房相关免疫偏离（ACAID）过程的关系。方法制作穿透角膜移植排斥反应和同一供体前房内注射脾细胞诱导ACAID的大鼠模型;角膜移植组进行排斥反应指数（RI）评分;ACAID组进行迟发型超敏反应（DTH）评价;采用免疫组织化学的方法检测CD86在角膜中的原位表达（以脾脏的表达为阳性对照）。结果角膜移植组植片均出现不同程度的新生血管、角膜水肿、混浊、增厚;ACAID组角膜透明,房水清,DTH评价术后2周及4周诱导成功率100％;免疫组织化学检测CD86在正常大鼠角膜组织全层无阳性表达,在移植后出现急性排斥反应的大鼠角膜上皮层中有大量阳性细胞表达,在ACAID诱导成功的大鼠角膜中未见阳性细胞表达。结论共刺激分子CD86参与移植后的急性排斥反应,但可能不参与免疫赦免过程。     

核因子-κB参与角膜移植排斥反应的实验研究

目的 研究核因子-κB(nuclear factor-κB,NF-κB)在角膜移植急性免疫排斥反应中的作用.方法 建立大鼠角膜移植模型90只,同基因移植组Wistar鼠供体10只,受体20只;同种异体移植组及同种异体移植 环孢霉素A(ciclosporin A,CsA)治疗组,均为Wistar大鼠10只为供体,SD大鼠20只为受体.各组术后不同时间点(3 d、7 d、12 d、18 d)测定角膜移植排斥反应指数评分,并于各时间点观察角膜植片病理学变化,检测NF-κB与细胞间黏附分子-1(intercellular adhesion molecule 1,ICAM-1)、血管内皮生长因子(vascular endothelial growth factor,VEGF)的表达.结果 角膜移植大鼠模型中,在观察期18 d 内,同基因组无1例出现排斥反应,同种异体组在各时间点的排斥反应指数显著高于同基因组(P＜0.05),而同种异体移植 CsA治疗组排斥反应较同种异体移植组明显受到抑制(P＜0.05).免疫组织化学结果显示NF-κB与ICAM-1、VEGF分布角膜上皮层、基质层及新生血管内皮细胞.在各时间点,同种异体移植组角膜中NF-κB与ICAM-1、VEGF的表达高于同基因移植组(P＜0.05),而低于同种异体移植 CsA治疗组(P＜0.05).对比观察发现NF-κB表达强度与排斥反应指数成正相关(r=0.901,P=0.000),且与下游基因ICAM-1(r=0.833,P=0.000)、VEGF(r=0.935,P=0.000)的表达强度成正相关.结论 NF-κB的激活参与角膜移植排斥反应的发生.CsA通过减弱NF-κB核转位和发挥活性,抑制受其调控的多种细胞因子、黏附分子等移植排斥相关因子的表达,从而抑制角膜移植排斥反应的发生发展.     

来氟米特活性代谢物A771726对大鼠角膜移植排斥反应的影响

目的探讨来氟米特活性代谢物A771726对大鼠角膜移植排斥反应的抑制作用。方法建立SD-Wistar大鼠同种异体穿透角膜移植模型,随机分组。A组为空白对照组;B、C、D组分别为0．5％、1．0％及2．0％A771726滴眼液组;E组为Wistar大鼠自体移植对照组。术后比较各组角膜植片排斥指数（RI）及植片存活时间,并对植片进行组织学及免疫组织化学染色观察。结果A组角膜植片存活时间为（9．38±2．26）d,B组（10．13±2．41）d,C组（17．57±1．72）d,D组（17．50±2．14）d,E组（〉28．00）d。A组、B组分别与C组、D组植片存活时间差异有统计学意义（P〈0．01）。移植术后10d,A组、B组角膜植片发生排斥反应,植片高表达IFN-γ及ICAM-1;术后20d,C组、D组植片发生排斥反应,植片IFN-γ及ICAM-1表达增高。结论局部应用A771726滴眼液能有效抑制角膜移植排斥反应。     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

Aberration and contrast sensitivity comparison of aspherical and monofocal and multifocal intraocular lens eyes

BACKGROUND: Higher-order aberrations and contrast sensitivity were evaluated in patients who underwent phacoemulsification cataract extraction followed by implantation of aspherical, monofocal or multifocal intraocular lens (IOL) replacements. METHODS: In this comparative trial, 124 patients with an average age of 66.8+/-5.2 years and their 124 eyes were randomly divided into three surgical implantation groups to receive one of three types of IOLs in replacement of cataract lenses. The patients of group 1 were given an aspherical IOL Z9001 (AMO, Santa Ana, CA, USA) replacement, and group 2 was implanted a monofocal IOL SA60AT (Alcon, Fort Worth, TX, USA) and group 3 the multifocal IOL SA40N (AMO). Post-surgical best-corrected visual acuity, corneal aberrations, total ocular aberrations, pupil diameters, capsulorhexsis sizes and contrast sensitivity were measured and compared. RESULTS: There was no statistical difference for mean best-corrected visual acuity, pupil diameter, curvilinear capsulorhexis size and corneal aberration among the three groups. For the spherical aberration, fourth-order higher-order aberration and total ocular higher-order aberration, the SA40N group was higher than the SA60AT group and the SA60AT group was higher than the Z9001 group, and the differences between the three groups were statistically significant for these measurements. Contrast sensitivity was higher for the Z9001 group than the SA60AT group and the SA60AT group was higher than the SA40N group, and the difference was statistically significant in all the spatial frequencies of 3, 6, 12 and 18. CONCLUSIONS: Although the multifocal IOL can provide near vision, it can increase higher-order aberration and negatively influence contrast sensitivity. However, the aspherical IOL can reduce aberration and improve contrast sensitivity as compared with the monofocal IOL.