视网膜微血管周细胞ET-1的分泌及影响

目的观察糖基化终产物(Advanced glycation end products,AGE)及低氧对培养的牛视网膜微血管周细胞(Bovine retinal microvascular pericytes,BRPs)内内皮素-1(Endothelin-1,ET-1)产生的影响.方法培养的BRPs分别与不同浓度的AGE(8,32,125μg/ml)共同培养4 d;低氧(10%O2,5%CO2,85%N2)条件下培养12、24、48 h;与不同浓度的AGE作用2 d后,再低氧培养48 h;培养结束后,分别收集培养液,离心,取上清液测定ET-1的含量.结果低氧能以时间依赖的方式促进BRPs分泌ET-1(γ=0.943,P＜0.01).AGE虽能使BRPs分泌ET-1轻微增加,但与对照组相比,差异无显著性(P＞0.05),而AGE能明显增强低氧对BRPs内ET-1分泌的诱导作用,两者具有协同效应.结论AGE和低氧能影响培养的BRPs内ET-1的产生,ET-1的产生异常可能是糖尿病视网膜病变中视网膜微循环血流动力学异常的原因之一.     

培养的牛视网膜毛细血管周细胞产生一氧化氮的影响

目的 观察糖基化终产物(ACE)、脂多糖(LPS)及低氧对培养的牛视网膜毛细血管周细胞(BRPs)内一氧化氮(NO)产生的影响。方法 培养的BRPs分别与不同质量浓度的AGE(8、32、125、500μg/ml)共同培养4d;LPS(10、20、40μg/ml)共同培养24h;低氧(5％O_2、5％CO_2、90％N_2)条件下培养12、24、48h。培养结束后,分别收集培养液,离心取上清液,用硝酸还原酶法检测其NO的浓度。结果 基础状态下,BRPs上清液中NO浓度为(37.25±4.37)μmol/L。低剂量的AGE(8μg/ml)与BRPs共同培养4d后,其上清液中NO的浓度为(68.37±9.92)μmol/L,是基础状态下BRPs上清液中NO浓度的1.8倍,随着AGE质量浓度的增加,BRPs上清液中NO的浓度迅速减少(r=0.835,P<0.01)。LPS及低氧能使BRPs产生NO明显增加(t=2.88,P<0.05及t=4.56,P<0.01),随着LPS质量浓度的增加和低氧时间的延长,BRPs上清液中NO的浓度也迅速上升(r=0.951,P<0.01和r=0.955,P<0.01)。结论 AGE、LPS和低氧能调节BRPs中NO的产生,NO与视网膜微循环血流动力学的调节有关。     

糖基化终产物诱导牛视网膜毛细血管周细胞凋亡及凋亡调节基因的表达

目的　研究糖基化终产物 (advancedglycosylationendproducts,AGE)对培养的牛视网膜毛细血管周细胞凋亡及凋亡调节基因Bax、bcl 2表达的影响 ,以探讨糖尿病视网膜病变的发病机制。方法　在体外培养 3～ 6代近融合的视网膜毛细血管周细胞中加入不同浓度的AGE(8、32、12 5、5 0 0及2 0 0 0mg/L)液 ,于 4d后检测不同浓度AGE对牛视网膜毛细血管周细胞凋亡及凋亡调节基因Bax、bcl 2表达的影响。结果　周细胞与AGE作用 4d后 ,呈现出典型的细胞凋亡特征 ;AGE促周细胞凋亡(r=0 878,P <0 0 1)和凋亡调节基因Bax的表达 (r=0 85 5 ,P <0 0 1)及抑制凋亡调节基因bcl 2的表达 (r=- 0 85 0 ,P <0 0 1)呈剂量依赖性 ;而周细胞凋亡率与Bax/bcl 2的比率呈正相关 (r=0 80 8,P<0 0 1)。结论　AGE能以剂量依赖的方式促进周细胞的凋亡 ,周细胞的凋亡率取决于凋亡调节基因Bax/bcl 2的比率。细胞凋亡是糖尿病视网膜病变中毛细血管周细胞早期丧失的一种方式。     

超氧化物歧化酶在视网膜毛细血管周细胞凋亡中的活性及意义

目的通过检测糖基化终产物（AGE）诱导培养的牛视网膜毛细血管周细胞凋亡及凋亡周细胞中超氧化物歧化酶（SOD）的活性及意义，进一步探讨糖尿病视网膜病变（DR）的发生机制。方法周细胞分别与不同浓度的AGE（0．47、1．88、7．5μmol／L）共同培养4d后，分别检测细胞凋亡、SOD活性，以及SOD对细胞凋亡及凋亡调节基因Bcl-2／Bax比率的影响。结果AGE能以浓度依赖的方式诱导周细胞凋亡（r=0．878，P〈0．01）、降低细胞内SOD的活性（r=-0．878，P〈0．01），而应用SOD能明显抑制AGE作用下的周细胞凋亡及提高凋亡调节基因Bcl-2／Bax的比率.结论凋亡及氧化应激的增加是DRP中周细胞选择性丧失的主要原因，SOD活性的下降是AGE诱导周细胞发生凋亡的关键因素。     

体外孵育的非酶糖基化终产物诱导正常大鼠类糖尿病性视网膜血管病变研究

目的　探讨外源性非酶糖基化终产物 (advancednon enzymaticglycationendproducts ,AGE)在血管壁的沉积与糖尿病性视网膜血管病变之间的关系。方法　将 16只健康两月龄SD大鼠 ,随机分为 4组 ,每组 4只鼠。正常对照组不做任何处理 ;糖尿病对照组应用AGE制作糖尿病模型 ;血清白蛋白 (ratserumalbumin ,RSA)组每日自鼠尾静脉注射RSA(4 0mg kg体重 ) ,连续注射 2周 ;AGE RSA组注射AGE RSA ,注射方法、剂量与RSA组相同。 2周后观察各组鼠视网膜毛细血管周细胞密度变化。结果　注射RSA组鼠视网膜毛细血管周细胞数平均为 (5 80± 0 4 8)个 每油镜视野 ,注射AGE组为(4 31± 0 34)个 每油镜视野 ,显示实验组毛细血管周细胞密度低于对照组 ,差异有显著意义 (F =7 16 4 ,P <0 0 1)。结论　外源性AGE注入正常大鼠会引起类糖尿病性视网膜血管病变 ,AGE可能是糖尿病性视网膜血管病变的独立致病因素之一。     

半胱氨酸天冬氨酸蛋白酶在视网膜毛细血管周细胞凋亡中的活性及意义

目的探讨糖基化终产物（AGE）在糖尿病视网膜病变（DR）发生中的作用。方法培养的牛视网膜毛细血管周细胞分别与不同浓度（0．47、1．88、7．50μmol／L）的AGE共同培养4d后,分别检测细胞凋亡、半胱氨酸天冬氨酸蛋白酶（caspase-3）活性及caspase-3抑制剂Z—DEVD-fmk对周细胞凋亡及凋亡调节基因Bcl-2／Bax比率的影响。结果AGE能以剂量依赖的方式诱导培养的牛视网膜毛细血管周细胞凋亡（r=0．867,P〈0．01）、增加细胞内caspase-3的活性,而选择性caspase-3抑制剂Z—DEVD—fmk能明显抑制AGE作用下的周细胞凋亡及提高凋亡调节基因Bcl-2／Bax的比率。结论凋亡是DR中视网膜毛细血管周细胞选择性丧失的机制之一,caspase-3活性的增加是AGE诱导周细胞发生凋亡的关键因素。     

视网膜血管内皮细胞和周细胞在酸性环境中的增生和凋亡

目的 探索酸中毒在视网膜新生血管生长的细胞机制中的作用.方法 原代培养获取牛视网膜血管内皮细胞(BRECs)和周细胞(BRPs);将传代后的细胞暴露在酸性环境中,通过细胞活力、细胞周期和细胞凋亡检测,观察细胞的增生和凋亡状况.结果 细胞培养得到纯化的BRECs和BRPs;酸中毒明显抑制BRECs和BRPs的生长(P<0.01);使处于S期的BRECs和BRPs减少(P<0.01),DNA合成受抑制.重度酸中毒抑制BRECs凋亡(P<0.05),引起BRPs凋亡(P<0.01).结论 酸中毒引起BRPs凋亡而抑制BRECs凋亡.提示视网膜酸中毒参与了糖尿病视网膜病变(DR)的新生血管生长过程.     

视网膜脱离复位术前后中心视野的对比研究

目的　探讨裂孔性视网膜脱离复位手术前后中心视野的改变 ,确定中心视野检查对评价视网膜脱离患者视功能恢复的意义。方法　选择临床确诊的裂孔性视网膜脱离患者 15例 15只眼 ,均采用巩膜扣带术使视网膜复位。手术前、术后分别采用瑞士Interzeag公司生产的Octopus 10 1型自动视野计进行视野检查。结果　手术前脱离区、非脱离区的平均光敏感度分别为 6 42 8± 8 2 2 8dB、17 0 2 0± 8 44 4dB ,两者差异有显著性 (t=4 3 0 0 ,P =0 0 1) ,而手术后脱离与非脱离区的光敏感度分别为 2 0 5 2 6± 4 191dB和 2 1 72 3± 3 82 5dB ,差异无显著性 (t =1 14 8,P =0 2 73 ) ;手术后脱离区、中心 10°视野的光敏感度分别由 6 42 9± 8 2 2 8dB提高至 2 0 5 2 6± 4 191dB和由 13 5 60± 10 614dB提高至2 5 5 40± 18 816dB ,较手术前都有明显提高 (t1=6 842 ,t2 =7 419,P <0 0 1) ;手术前后非脱离区的光敏感度分别为 2 0 0 92± 6 2 3 2dB和 2 1 72 3± 3 82 5dB ,差异无显著性 (t=1 2 63 ,P =0 2 3 11) ;手术前后的中心 10°视野平均光敏感度与视力呈正相关 (r1=0 5 3 7,r2 =0 5 5 1,P <0 0 5 )。结论　自动视野检查能定量地反映视网膜复位后视功能恢复 ,它具有方便、稳定、能定位等优点 ,是评价裂     

高级糖基化终末产物与糖尿病视网膜病变的关系

高级糖基化终末产物(advanced glycation end products,AGE)的堆积是糖尿病视网膜病变(diabetic retinopathy,DR)主要的致病因素,其可促进视网膜色素上皮(retinal pigment epithelium,RPE)细胞AGE受体(receptor of AGE,RAGE)的表达、血管内皮生长因子(vascular endothelial growth factor,VEGF)的分泌及细胞凋亡损伤.RPE细胞参与构成视网膜的外屏障,具有屏障、滤过、吞噬和分泌等作用,在维持视网膜正常生理功能方面具有重要作用,RPE细胞的功能损害会导致多种视网膜疾病.通过研究AGE对RPE细胞的损伤,探讨AGE在DR发生发展中的作用,有利于寻找有效防治DR的新途径.     

明胶酶A及血管内皮细胞生长因子在翼状胬肉组织中的表达

目的探讨血管内皮细胞生长因子(vascularendothelialgrowthfactor,VEGF)、明胶酶A与翼状胬肉发生、浸润的关系。方法术中切除的31例翼状胬肉标本制成冰冻切片,经免疫组织化学方法检测翼状胬肉组织中VEGF、明胶酶A的表达,并与正常结膜组织中VEGF、明胶酶A的表达对比,以半定量分法评价并统计其结果。结果正常结膜组织与翼状胬肉上皮组织VEGF表达阴性、弱阳性、强阳性例数分别为6、2、0和0、8、23(χ2=29.187),明胶酶A表达阴性、弱阳性、强阳性例数分别为8、0、0和0、8、23(χ2=39·00),差异都有极显著意义(P<0.001)。静止期与进展期翼状胬肉上皮组织VEGF表达弱阳性、强阳性例数分别为4、19和4、4(χ2=4.216,P<0.05),明胶酶A表达弱阳性、强阳性例数分别为2、21和6、2(χ2=12.816,P<0.001),差异有显著意义。结论VEGF、明胶酶A在翼状胬肉组织中过度表达,其表达量与翼状胬肉的病理分期密切相关,提示二者在翼状胬肉的形成和浸润过程中起重要作用。     

Strabisme Alternant - Etude clinique - traitement

The author defines motor and sensory alternation: the term alternation should not be used in isolation, it should always be accompanied by the name of the parameter concerned. Sensory alternation is always found together with motor alternation but the reverse is not true.The examining criteria for a diagnosis of sensory alternation are given, sensory alternation must not be confused with alternating inhibition. Working from clinical observations of cases of motor alternating strabismus, the author selects 2 types of binocular sensory relations which allow one to differentiate between:- cases of primary alternating strabismus- cases of secondary alternating strabismusThese forms will develop in different ways; in both cases a cure is possible providing that the right treatment is prescribed and once prescribed carefully followed, etc. It is always a case of serious forms of strabismus whose developmental period is spread over several years.According to the authors, the frequency of cases of true primary strabismus is from 1–3%, the frequency of cases of secondary alternating strabismus varies according to the type of therapy practised on cases of monocular strabismus with amblyopia. These latter will become cases of alternating strabismus under the influence of certain types of therapy carried out over several years (penalization, rocking, alternated occlusion, etc...).Experimental data on kittens confirm clinical data; kittens placed in abnormal environments during the sensitive period will show modification in the distribution of cortical cells and the absence of binocular cells (either because the excitation of the two eyes was not simultaneous, or not identical: artificial strabismus, occlusion, opaque glasses). This disturbances become irreversible after a certain period of exposure (a function of age, length of exposure, etc...).It is thus necessary to bear in mind: 1) the iatrogenic risks of certain orthoptic treatments, 2) the necessity for a binocular form of treatment as soon as possible, as once a certain stage is passed, cortical plasticity diminishes and the elaboration of normal binocular relations becomes impossible.

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Current Thoughts on the Aetiology of Ocular Changes during Contact Lens Wear

ABSTRACT: Contact lenses are known to produce changes to the ocular tissues, and this review attempts to give a comprehensive assemblage of the knowledge on the aetiology of such changes. To achieve this result, the changes are categorized by structure and function, and discussed according to the temporal nature of occurrence where appropriate. Although assessment of the importance of a particular tissue change is difficult, this overview enables some degree of judgement to be made on the aetiology of the major side-effects of contact lens wear. This gives a basis on which to modify aspects of contact lens wear to ultimately increase the success rate.     

The detection of motion in chromatic stimuli: first-order and second-order spatial structure

This study provides evidence for the existence of a low-level chromatic motion mechanism and further elucidates the conditions under which its operation becomes measurable in an experimental stimulus. Observers discriminated the direction of motion of amplitude modulated (AM) gratings that were defined by luminance or chromatic variation and masked with spatiotemporally broadband luminance or chromatic noise. The size and retinal location of the stimuli were varied and the effects of broadband noise and grating masks were both compared with the cohort of stimuli. Some significant disparities in the published literature were well explained by the results. In conclusion, evidence for a chromatically sensitive motion mechanism that evades the, detrimental effects of a luminance mask was found only at the fovea and only when the stimulus was small and centrally placed.     

Local chemotherapeutic agents for the treatment of ocular malignancies

We critically analyze available peer-reviewed literature, including clinical trials and case reports, on local ocular cancer treatments. Recent innovations in many areas of ocular oncology have introduced promising new therapies, but, for the most part, the optimal treatment of ocular malignancies remains elusive.