水通道蛋白与青光眼

水通道蛋白(Aquaporins,AQPs)是一种广泛分布于机体内的跨膜转运蛋白,它主要参与液体的分泌和吸收,在机体组织细胞液体的转运中起着至关重要的作用.目前已发现眼组织中液体的分泌和吸收与AQPs分布具有密切的相关性.本文就AQPs在眼组织的分布、与青光眼的可能关系以及某些抗青光眼药物的作用机制等方面进行综述.     

水通道蛋白与眼病

水通道蛋白 (aquaporin ,AQPs)是存在于动植物及微生物细胞膜上转运水的特异孔道。目前已鉴定出 8种水通道蛋白 ,不同水通道蛋白之间具有类似的特征。众多的研究证实这类蛋白质对维持机体的正常状态至关重要 ,且与水平衡紊乱所致的临床症状密切相关。本文综述了近年来水通道蛋白的研究进展 ,并重点讨论水通道蛋白在眼的分布及其与眼病的可能关系。     

水通道蛋白与眼病

水通道蛋白（aquaporin,AQPs)是存在于动植物及微生物细胞膜上转运水的特异孔道，目前已鉴定出8种水通道蛋白，不同水通道蛋白之间具有类似的特征，众多的研究证实这类蛋白质对维持机体的正常状态至关重要，且与水平衡紊乱所致的临床症状密切相关，本综述了近年来水通道蛋白的研究进展，并重点讨论水通道蛋白在眼的分布及其与眼病的可能关系。     

水通道蛋白与先天性白内障研究进展

水通道蛋白(aquaporins,AQPs)主要介导自由水沿渗透压梯度被动跨生物膜转运,水通道蛋白在保持细胞内外环境的稳态平衡,完成生理功能方面发挥着重要的作用。晶状体纤维细胞中只表达三种水通道蛋白：AQP1、AQP0和AQP5,三种AQPs的不同功能及空间差异表达促进产生和调节微循环系统。AQPs相关基因的改变可导致白内障的发生。本文综述了近年来对AQP1、AQP0和AQP5研究,并讨论了其与先天性白内障发生的关系。     

水通道蛋白1与角膜内皮

水通道蛋白(aquaporins，AQPs)是存在于动植物及微生物细胞膜上的一组与水通透有关的转运蛋白，参与许多生理过程，维持机体的正常状态。第一个水通道蛋白AQPl的cDNA序列是在1991年完成鉴定的，它存在于包括眼在内的多种组织和细胞中。角膜内皮细胞上也发现有AQPl的表达，随着对AQPl结构及功能认识的逐步深入，发现其跨膜水转运功能及其他的可能功能对角膜病变的阐明与角膜透明的维持至关重要。     

水通道蛋白与年龄相关性白内障关系的研究进展

水通道蛋白(AQPs)结构的研究进一步加深了人们对于这种小分子膜蛋白对水和溶质转运的认识。迄今,在晶状体中有两种AQPs表达被报道,即AQP0和AQP1。我们主要就AQPs在晶状体的分布、功能及与白内障形成的可能关系进行讨论。     

水通道蛋白-1的研究进展

近1O多年来大量研究证实机体内广泛存在着特异性水通道家族(aquaporins,AQPs).由于它们在生命活动中的重要性,对其发现及其结构、功能的研究一直是近年来生物学界的热点,其中对AQP-1的研究最深入.本文介绍水通道蛋白-1的发现,分子结构和遗传学特点,重点介绍水通道蛋白在眼科和耳鼻咽喉科领域内的研究进展.     

水通道蛋白与白内障研究进展

水通道蛋白(aquaporins,AQPs)主要介导自由水沿渗透压梯度的被动跨生物膜转运,对水有高度选择性。晶状体只有两种水通道蛋白,晶状体上皮细胞表达的AQP1和晶状体纤维细胞表达的AQP0,它们共同调节晶状体水代谢,维持晶状体生理功能及透明性,其异常表达可导致白内障的发生。术文综述了近年来对水通道蛋白0,1的研究,并讨论水通道蛋白与白内障发生的关系。     

眼与水通道蛋白的研究进展

水的跨膜转运有 2条基本途径 :跨越脂质双层的简单扩散和通道介导的水转运。不同组织扩散水通透性 (diffusionalwater permeability,Pd)不同 ,如果 Pf/ Pd≈ 1(渗透水通透性 :osm otic water perm eability,Pf,是反映水在跨膜梯度存在下的渗透情况 )表明水的跨膜运动是通过简单扩散完成的。而通道介导的水转运 ,不能仅用简单扩散来解释。其 Pf较高 ,而活化能较低 (Ea<5 kal· mol- 1 ) ,且 Pf/ Pd>1,可特异地介导大量的水向高渗方向移动。AQPs介导这一类水转运。1　水通道蛋白家族的结构、分布与功能目前的水通道蛋白家族包括 10个成员…     

胡臻主任应用升阳疗法治疗眼科疾病举隅

升阳疗法是治疗眼科疾病的常用治法，可配合益气、健脾、疏肝、活血、利水、清热、补肾等灵活应用。临床用药以升麻、葛根、羌活、防风、川芎、柴胡等最为多见。升阳疗法在干眼合并眼睑痉挛、中心性浆液性脉络膜视网膜病变、葡萄膜炎、动眼神经麻痹等疾病诊治中均获得较好疗效。现通过归纳总结胡臻主任升阳疗法理论及眼科疾病用药特点，并结合病案总结升阳疗法治疗眼科疾病经验。表明升阳疗法在治疗眼科疾病中应用广泛，疗效显著。     

Role of aquaporin water channels in eye function

The aquaporins (AQPs) are a family of more than 10 homologous water transporting proteins expressed in many mammalian epithelia and endothelia. At least five AQPs are expressed in the eye: AQP0 (MIP) in lens fiber, AQP1 in cornea endothelium, ciliary and lens epithelia and trabecular meshwork, AQP3 in conjunctiva, AQP4 in ciliary epithelium and retinal Müller cells, and AQP5 in corneal and lacrimal gland epithelia. This cell-specific expression pattern suggests involvement of AQPs in corneal and lens transparency, intraocular pressure (IOP) regulation, retinal signal transduction, and tear secretion. Indeed, humans with mutant AQP0 develop cataracts. Mice lacking AQP1 have reduced IOP and impaired corneal transparency after swelling, and mice lacking AQP4 have reduced light-evoked potentials by electroretinography. There is evidence for impaired cellular processing of AQP5 in lacrimal glands of humans with Sjogren's syndrome. AQPs facilitate fluid secretion and absorption in the eye, and hence are involved in the regulation of pressure, volume and tissue hydration. Pharmacological alteration of AQP function may provide a new approach for therapy of glaucoma, corneal edema, and other diseases of the eye associated with abnormalities in IOP or tissue hydration.     

外泌体及其与眼科疾病的免疫学关系

外泌体是细胞内多囊泡体与细胞膜融合后主动分泌到胞外的纳米级小囊泡。外泌体能够通过其携带的蛋白质或RNA影响免疫调控网络,进而影响眼内细胞的生理或病理过程。干细胞或眼内细胞分泌的外泌体在一些眼科疾病的发病及损伤修复机制中起重要的免疫调控作用。本文就外泌体的来源与特性、外泌体在眼科疾病中发挥的免疫学作用展开讨论,从而为进一步揭示外泌体免疫调节作用机制及治疗策略提供参考资料。     

工程技术在眼视光医疗器械的应用进展

眼睛既是复杂的生物器官,也是精密的光学器官。相较于其他临床专科,生物医学工程领域的相关技术在眼科的应用前景很大,眼科不断引进各种生物材料及新式医疗器械。现就眼科临床诊疗技术和器械中常用的生物医学工程技术进行系统的概括,以促进这类技术及器械在临床中更好地应用。     

长链非编码RNA在视网膜色素上皮相关视网膜疾病中的研究进展

视网膜色素上皮对维持光感受器及其他视网膜细胞的存活和正常生理功能具有重要意义,其病变可引起众多视网膜疾病的发生发展。近年来有研究表明,长链非编码RNA(LncRNA)在眼部相关疾病中存在差异表达,并对不同类型眼病的发生发展起调控作用。这提示LncRNA可以作为基因诊断和治疗眼科疾病的新靶点。视网膜色素上皮细胞对视网膜功能具有不可忽视的作用,若从LncRNA角度对其进行研究,将对视网膜疾病的诊断与治疗开辟新的道路。     

A Case of Reversed Ophthalmic Artery Flow without Occlusion of the Internal Carotid Artery

Background: We report a case of reversed ophthalmic artery (OA) flow showing neither occlusion of the internal carotid artery (ICA) nor ophthalmic symptoms.Case: An 82-year-old man had transient blindness in both eyes. After left carotid endarterectomy, ophthalmic symptoms improved in the right and left eyes. Afterwards, he had a relapse in the left eye.Results: There was no unusual impression in the ophthalmic examinations, but color Doppler imaging showed reduced flow in the left OA, reversal of flow direction in the right OA. The central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were not detected in the left eye but were detected in the right eye. Digital subtraction angiography demonstrated that the right OA was not contrasted with the right ICA, despite there being no stenosis or occlusion of the right ICA.Conclusions: We suggest that carotid surgery may affect the ocular circulation of the opposite side, and reversed OA flow as a collateral pathway from the external carotid artery may occur in the absence of carotid artery stenosis. Good circulation of the CRA and SPCA may preclude manifestation of ophthalmic symptoms even if the OA flow is reversed.     

A case of reversed ophthalmic artery flow without occlusion of the internal carotid artery

BACKGROUND: We report a case of reversed ophthalmic artery (OA) flow showing neither occlusion of the internal carotid artery (ICA) nor ophthalmic symptoms. CASE: An 82-year-old man had transient blindness in both eyes. After left carotid endarterectomy, ophthalmic symptoms improved in the right and left eyes. Afterwards, he had a relapse in the left eye. RESULTS: There was no unusual impression in the ophthalmic examinations, but color Doppler imaging showed reduced flow in the left OA, reversal of flow direction in the right OA. The central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were not detected in the left eye but were detected in the right eye. Digital subtraction angiography demonstrated that the right OA was not contrasted with the right ICA, despite there being no stenosis or occlusion of the right ICA. CONCLUSIONS: We suggest that carotid surgery may affect the ocular circulation of the opposite side, and reversed OA flow as a collateral pathway from the external carotid artery may occur in the absence of carotid artery stenosis. Good circulation of the CRA and SPCA may preclude manifestation of ophthalmic symptoms even if the OA flow is reversed.     

Potential systemic side effects of six common ophthalmic drugs

Drugs applied topically on the eye are partly absorbed into the eye (possibly 2 to 10%), the remainder can enter the systemic circulation through the conjuctival vessels or from the vessles of the nasolacrimal passages. Drug molecules which enter the stomach and are not transformed into inactive compounds may also enter the blood stream. Systemic reactions to topically applied ophthalmic drugs are shown to be rare and largely preventable.     

Potential Systemic Side Effects of Six Common Ophthalmic Drugs*

Drugs applied topically on the eye are partly absorbed into the eye (possibly 2 to 10%), the remainder can enter the systemic circulation through the conjuctival vessels or from the vessels of the nasolacrhnal passages. Drug molecules which enter the stomach and are not transformed into inactive compounds may also enter the blood stream. Systemic reactions to topically applied ophthalmic drugs are shown to be rare and largely preventable.     

Endothelin-1-mediated retinal artery vasospasm and the rabbit electroretinogram.

Electroretinogram (ERG) changes invariably accompany the selective interruption of the retinal circulation that occurs in human central retinal artery occlusion. Since arteriolar ligation or ocular hypertension in the rabbit eye is occasionally used to model human central retinal artery occlusion, we conducted the present study to determine whether selective interruption of the retinal circulation of the rabbit eye alters retinal function as measured by the ERG. The vasoconstrictor, endothelin-1, was injected into the vitreous of rabbits' eyes to induce complete vasospasm and selective interruption of the retinal circulation. This procedure was compared to vascular ligation of the ophthalmic and ciliary arteries in which both the retinal and choroidal circulations were interrupted. A total of 8 rabbits was studied. Circulation was monitored angiographically in half of the eyes, and retinal function was monitored by the ERG in the remaining eyes. Endothelin-1 obliterated retinal arteriolar blood flow without affecting choroidal blood flow for at least 1 hr. Although ERG a-wave amplitude showed a small decline over 2 hr, b-wave and oscillatory potential amplitudes (measures of inner retinal function) showed no loss over this period. In contrast, ligation of the ophthalmic and ciliary arteries produced complete obliteration of both retinal arteriolar and choroidal blood flow and complete loss of the ERG after 2 min. Endothelin-1 induces acute, selective interruption of retinal arteriolar blood flow which has no significant physiologic effect on inner retinal function of the rabbit as monitored by the ERG. The avascular rabbit retina appears to be a poor choice for modeling human retinal artery occlusion.