Fas和FasL在鼻息肉组织中的表达

目的探讨Fas和FasL在鼻息肉组织中的表达情况以及这二种凋亡相关蛋白在鼻息肉发病中的关系.方法应用S-P免疫组化法检测35例鼻息肉组织及15例下鼻甲组织中Fas和FasL的表达情况.结果(1)Fas在鼻息肉上皮及腺上皮的表达弱于对照组(P＜0.05),在嗜酸性粒细胞中表达广泛.(2)FasL在鼻息肉上皮及腺上皮的表达强于对照组(P＜O.05),未见FasL在嗜酸性粒细胞中表达.(3)鼻息肉上皮细胞中Fas和FasL蛋白的表达无相关性(P＞0.05).结论(1)Fas和FasL在鼻息肉发生发展中起一定的作用.(2)Fas、FasL在鼻息肉上皮细胞的凋亡过程中各自独立起作用.     

增生性玻璃体视网膜病变玻璃体切割液内的细胞凋亡

目的检测增生性玻璃体视网膜病变(proliferative vitreoretinopathy,PVR)玻璃体切割液标本内是否存在细胞凋亡,观察Fas抗原(Fas)和Fas配体(Fas ligand,FasL)与细胞凋亡的关系。方法11例PVR新鲜玻璃体 切割液标本细胞离心涂片,末端标记(terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labelling,TUNEL)染色检测凋亡细胞,以及Fas、FasL和细胞类型特异抗原细胞角蛋白(cytokeratin,CK)免疫组织化学检测, 并与2例角膜移植后的供体眼正常对照标本的上述检查结果相对比。　结果正常人视网膜Fas和FasL弱表达。Fas、FasL、CK和凋亡见于所有PVR玻璃体切割液标本。TUNEL阳性细胞占总细胞数的20.53%。70.35%、51.58%和82.97%的细胞分别高表达Fas、FasL和CK。Fas和凋亡的直线相关系数为0.99(P<0.001)。结论PVR眼玻璃体切割液标本可见Fas、FasL的表达和细胞凋亡。Fas和FasL的高表达可能与PVR中增生的视网膜色素上皮细胞凋亡有关。(中华眼底病杂志,1999,15:78-80)     

大鼠角膜碱烧伤后视网膜细胞凋亡的研究

目的研究严重眼前段碱烧伤后视网膜组织内的细胞凋亡情况,以及Fas抗原(Fas)和Fas配体(Fas ligand,FasL)表达与细胞凋亡的关系。方法制作大鼠角膜严重碱烧伤模型。在烧伤的不同阶段,应用TUNEL法检测凋亡细胞、免疫组织化学法检测Fas、FasL在视网膜组织中的表达和变化,并与正常大鼠相对照。结果正常视网膜中基本未见TUNEL阳性细胞,碱烧伤3d后在视网膜神经节细胞、内核层细胞和内层血管内皮细胞中均可见不同程度的TUNEL阳性细胞。正常视网膜未见Fas表达,实验各组中均可见不同程度的Fas表达;正常视网膜FasL弱表达,实验各组FasL表达显著增强,与正常对照组比较差异有显著性(P<0.01)。Fas和FasL表达与凋亡之间具有较好的相关性,相关系数分别为0.899(P<0.01)和0.504(P<0.01)。结论严重眼前段碱烧伤后视网膜组织细胞存在异常凋亡,凋亡可能与Fas/FasL系统有关。     

增生性玻璃体视网膜病变增殖膜的免疫组织化学及细胞凋亡研究

目的　检测增生性玻璃体视网膜病变 (PVR)增殖膜标本中细胞Fas、Fas配体 (Fasligand ,FasL)的表达和凋亡 ,并探讨Fas/FasL与凋亡的关系。方法　通过免疫组织化学的方法检测 12例增殖膜标本Fas和FasL的表达 ,TUNEL技术检测凋亡细胞。结果　PVR增殖膜标本中Fas和FasL阳性细胞百分率分别为 60 6%和 43 75 % ,偶见两者同时表达的细胞。 5例前膜和 2例下膜标本可见TUNEL染色阳性细胞核。凋亡与Fas、FasL相关系数均为 0 77(t =3 82 ,P <0 0 5 ) ,PVR病程与凋亡的r值为 0 74(t =3 11,P <0 0 1)。结论　Fas、FasL高表达与凋亡的正相关性提示 ,通过Fas/FasL系统诱导增殖细胞及炎症细胞凋亡 ,可能成为临床防治PVR的新策略     

α-硫辛酸治疗大鼠视网膜缺血再灌注损伤Fas/FasL的表达与细胞凋亡的关系

目的:探讨Fas/FasL在大鼠视网膜缺血再灌注损伤(retinal ischemia reperfusion injury,RIRI)中的表达与细胞凋亡的关系及α-硫辛酸(α-LA)的治疗作用。方法:采用升高眼内压的方法建立RIRI模型,将54只SD大鼠随机分为正常组、缺血再灌注(IR)组和α-LA干预组,IR组及α-LA干预组在12,24,48,72h光镜观察视网膜内层厚度及神经节细胞丢失,TUNEL法检测视网膜神经细胞凋亡,免疫组织化学法检测视网膜组织Fas/FasL蛋白的表达。结果:IR组视网膜内层变薄,神经节细胞数目减少。细胞凋亡出现于再灌注后12h,并逐渐递增,24h达到高峰,48h开始下降。Fas/FasL表达与凋亡的神经细胞改变基本一致。α-LA干预组视网膜内层厚度和神经节细胞数目有一定恢复。凋亡细胞在12,24,48h组明显低于IR组(P<0.05);Fas表达在12,24h组较IR组显著下降(P<0.05);FasL表达在12,24,48h组较IR组明显下降(P<0.05)。结论:Fas/FasL系统参与RIRI,导致神经节细胞凋亡;α-LA可下调Fas/FasL表达,减少神经节细胞凋亡。     

果糖二磷酸镁对大鼠视网膜缺血再灌注损伤的保护作用

目的 探讨果糖二磷酸镁(magnesium fructose diphosphata,FDPMg)时实验性大鼠视网膜缺血再灌注损伤的影响及其作用机制.方法 通过升高眼压的方法,制作大鼠实验性视网膜缺血再灌注损伤的模型.将66只SD大鼠随机分为正常组、缺血再灌注模型组、FDPMg干预组.后两组各分为6 h、12 h、24 h、48 h、72 h 5个时间段.采用DNA原位末端标记法检测凋亡的视网膜细胞;免疫组织化学法检测视网膜组织中Fas/FasL蛋白的表达变化.结果 正常组大鼠视网膜未见凋亡细胞.缺血再灌注模型组再灌注6 h可观察到凋亡细胞;12 h凋亡细胞逐渐增加;24 h细胞凋亡达高峰;48 h凋亡细胞减少;72 h视网膜仍可见凋亡细胞.各组Fas/FasL表达情况与视网膜细胞凋亡情况基本一致.FDPMg干预组各时段各观察指标表达均较缺血再灌注模型组明显下降,两组间比较差异均有显著统计学意义(均为P＜0.01).结论 FDPMg明显抑制Fas/FasL蛋白在视网膜缺血再灌注损伤中的表达,进而抑制细胞凋亡来实现其对视网膜缺血再灌注损伤的保护作用.     

胎儿角膜深低温保存对FAS/FASL蛋白表达的影响

目的:研究细胞凋亡信号分子Fas和细胞凋亡因子FasL在新鲜及深低温保存后胎儿角膜的表达情况。方法:应用免疫组织化学SABC法对33例不同胎龄(5mo至足月)胎儿角膜石蜡标本切片后,分别进行了Fas和FasL蛋白染色。结果:胎儿角膜细胞Fas蛋白及FasL蛋白全为胞质和/或胞膜着色。33/33例角膜上皮细胞、基质细胞及内皮细胞Fas蛋白阳性表达,经统计学分析,未发现不同月龄间有差异。33/33角膜上皮细胞及内皮细胞FasL蛋白阳性表达,经统计学分析,未发现不同月龄间有差异,角膜基质细胞FasL蛋白的表达为0/33。新鲜角膜和冷冻保存后角膜的Fas,FasL蛋白阳性表达量经统计学分析无差别。结论:新鲜和深低温保存后的5mo至足月龄胎儿角膜均可见Fas,FasL蛋白的表达。其中Fas在角膜上皮、基质和内皮细胞均表达,FasL在角膜上皮、内皮细胞表达,而基质细胞不表达。深低温保存对胎儿角膜Fas/FasL蛋白表达无影响。     

辅酶Q10对大鼠紫外线光损伤角膜上皮细胞凋亡相关基因表达的影响

目的 研究辅酶Q10对紫外线所致角膜上皮细胞光损伤防护作用.方法 36只wistar雄性大鼠随机分为正常对照组、阳性对照组与辅酶Q10治疗组.紫外线连续照射24 h建立角膜上皮紫外线光损伤模型.治疗组于光照前3周每天辅酶Q10灌胃.观察角膜组织病理学改变并用免疫组化染色观察凋亡相关基因蛋白Bcl-2、Bax、Fas和FasL的表达,进行细胞计数与统计学检验.结果 正常对照组角膜上皮可以见到Bcl-2、Fas和FasL的阳性表达,很少见到Bax的阳性表达.阳性对照组和辅酶Q10治疗组均可以见到Bcl-2、Bax、Fas和FasL的表达.与正常组比较,阳性组Bcl-2表达阳性的角膜上皮细胞数显著减少,Bax表达阳性的角膜上皮细胞数显著增多(P＜0.01);治疗组Bcl-2、Bax表达阳性的细胞数与正常组相比无明显变化(P＞0.05);而阳性组Fas和FasL表达阳性的角膜上皮细胞数明显增多(P＜0.01),治疗组Fas和FasL表达阳性细胞数明显少于阳性组(P＜0.05).结论 辅酶Q10通过上调Bcl-2的表达,下调Bax、Fas和FasL的表达,能够阻抑凋亡过程和细胞的死亡.     

维生素A缺乏兔干眼病模型角膜上皮细胞凋亡及相关蛋白表达的关系

目的 探讨维生素A缺乏兔干眼病模型角膜上皮细胞凋亡与相关蛋白表达的关系.方法 制作维生素A缺乏兔干眼病模型,采用原位末端标记及免疫组织化学法,对兔模型组及对照组各12只24眼角膜上皮细胞中的凋亡细胞及Fas、FasL、Bax和bcl-2等相关蛋白的表达进行检测.结果 兔干眼病模型组每高倍视野角膜上皮细胞凋亡数为4.69±1.06,对照组为0.25±0.13,差异有统计学意义(P＜0.01).模型组角膜上皮细胞中,每1 000个细胞阳性蛋白表达的细胞数分别为Fas 207.67±56.17、FasL 228.33 4±61.09、Bax 175.03±43.23,均明显高于对照组Fas 64.45±37.23、FasL68.35±35.88、Bax47.77±29.32(P＜0.01),与凋亡细胞数呈正相关(r:0.87,0.94,0.90);bcl-2阳性表达的细胞数为56.19±36.67,明显低于对照组190.83±52.07(P＜0.01),与凋亡细胞数呈负相关(r=-0.81).结论 维生素A缺乏兔角膜组织上皮细胞Fas、FasL及Bax增加及bcl-2的减少均可促进细胞凋亡.     

干燥综合征泪腺组织中细胞凋亡及相关基因表达的研究

目的　探讨干燥综合征 (Sj gren′ssyndrome,SS)患者泪腺组织上皮细胞凋亡及其相关基因表达与SS组织损伤的关系。方法　采用原位末端标记及免疫组织化学的方法 ,对 12例SS患者及7例对照泪腺组织上皮细胞中的凋亡细胞及Fas、FasL、bcl 2和Bax等相关基因蛋白的表达进行检测。结果　 12例SS患者泪腺组织中上皮细胞凋亡数为 (8 83± 3 2 7)个 /高倍视野 ;对照为 (0 88± 0 5 2 )个 /高倍视野 (P =0 0 0 0 )。SS患者泪腺导管及腺泡上皮细胞中 ,Fas、FasL及Bax阳性表达的细胞数均明显高于对照组 (P =0 0 0 0 ) ,与凋亡细胞数呈正相关 (R =0 83,0 88,0 8;P =0 0 0 0 ) ;bcl 2阳性表达的细胞数明显低于对照组 ,与凋亡细胞数呈负相关 (R =- 0 6 9,P =0 0 0 1)。结论　SS患者泪腺组织中上皮细胞凋亡可能是导致腺体破坏进而功能丧失的原因之一 ;Fas、FasL及Bax增加以及bcl 2的减少皆与促进细胞凋亡有关     

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.     

Proximal and accommodative convergence and age

The authors have estimated the phoria for distant and near fixation in two groups of subjects (mean age 27.5 ± 4.4 and 59.2 ± 8.2 years). Different accommodative stimuli were induced by adding minus lenses for distant fixation and plus lenses for near fixation. Statistical analysis of the experimental data indicates that, for distant fixation, the value of phoria per unit of accommodative stimulus is significantly lower in presbyopic than in nonpresbyopic subjects. Also, during near fixation, the accommodative convergence (AC/A ratio) is more reliable in the presbyopic subjects when the accommodative stimulus is progressively reduced. This varying behavior indicates in presbyopic subjects that proximal convergence is of greater relative importance in the determination of the fusion-free position. In nonpresbyopic subjects, accommodative convergence is the more important component.     

Anesthesia and preoperative and postoperative medications

Although certain methods such as retrobulbar blocks are used extensively, improvements in procedure can always be implemented. The use of ultrasound, low concentrations of anesthesia, careful monitoring, and, in the case of risk patients, anesthesia standby are all important considerations to ensure uneventful treatments. Topical anesthesia eliminates needle risk as well as risk of ptosis and bruising. Because it has been demonstrated that bacteria routinely enter the anterior chamber during uncomplicated cataract surgery, certain irrigation solutions are helpful, but still debatable. Postoperatively, diclofenac, flurbiprofen, and timolol have all been proven to be effective in reducing ocular inflammation, reducing incidence of CME, and controlling pressure increase, respectively.     

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.     

Anesthesia and preoperative and postoperative medications

Retrobulbar blocks, although widely used, still have potentially serious complications. Topical anesthesia presents less risk of injury to the globe and less pain but requires careful usage and an experienced surgeon. New techniques, however, allow for an increase in the percentage of patients able to have topical anesthesia. Preoperatively, 2.5% phenylephrine is found to be just as effective as 10% phenylephrine, and, when compared with wound closure and surgeon's experience, the effect of prophylactic medications was found to be negated. Postoperatively, diclofenac is found to be as effective an anti-inflammatory agent as prednisolone. Also, the addition of 10% phenylephrine to 4% pilocarpine drops enhances the effectiveness of pharmacologic treatment of postoperative iridocorneal adhesions. In addition, ophthalmologists should be aware of emerging antibiotic resistance.     

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.     

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.