靶向血管内皮生长因子治疗眼新生血管的研究进展

眼新生血管的形成严重破坏眼的结构和功能,引起不同程度的视力障碍,因此研究新生血管的生成机制并寻找有效的治疗方案是目前急需攻克的研究课题.血管内皮生长因子(vascular endothelial growth factor,VEGF)是目前发现的最为强大和专一的刺激内皮细胞增生的因子,在新生血管生成中起着中心作用.通过眼内注射VEGF 受体嵌合蛋白、抗VEGF单克隆抗体、靶向VEGF 小干扰RNA均可不同程度地抑制眼内新生血管生成.本文就靶向VEGF治疗眼新生血管的研究进展进行综述.     

特发性脉络膜新生血管患者血清中血管内皮生长因子和色素上皮衍生因子的表达

脉络膜新生血管(CNV)的形成受多种细胞因子调控.血管内皮生长因子(VEGF)可促进血管内皮细胞分裂生长,导致血管增生和渗透性增加,是最重要的新生血管促进因子之一[1].色素上皮衍生因子(PEDF)是一种内生新生血管抑制因子,可以同时抑制血管内皮细胞的迁移和增生[2].已有研究表明,VEGF和PEDF表达水平失衡与CNV形成密切相关[3].但有关VEGF和PEDF在特发性CNV (ICNV)患者血清中的表达研究还较为少见.为此,我们对一组ICNV患者血清中VEGF和PEDF的表达水平进行了检测,以期探讨VEGF和PEDF与CNV形成的关系.现将结果报道如下.     

血管内皮生长因子和眼内新生血管

八十年代末分离提纯的血管内皮生长因子(vascular endothelial growth factor,VEGF)是一种可溶性糖蛋白，具有促血管内皮细胞分裂、增生和提高血管通透性等作用。越来越多的证据表明，VEGF在生理性和病理性的血管新生过程中起着关键性的作用，对VEGF的研究引发了基础、临床多个学科的突破性进展。VEGF很可能就是眼科界寻找了半个世纪的“视网膜未知因子”。VEGF的发现和认识以及VEGF与眼内新生血管关系的阐明对于人眼新生血管的基础和临床研究具有重要意义。 (中华眼底病杂志,1999,15:62-64)     

VEGF与眼内血管新生

眼内新生血管是很多眼病致盲的重要原因,例如糖尿病视网膜病变、年龄相关性黄斑变性、早产儿视网膜病变、视网膜中央或分支静脉阻塞、角膜炎和眼外伤等.生长因子中的血管内皮生长因子(vascular endothelial growth factor,VEGF)家族是眼内血管新生的关键因素.在一些眼病中,它通过调控病理性血管发生和增加血管通透性而起作用.本文我们主要阐述眼内新生血管的形成机制和治疗方面的新进展,对VEGF 家族的结构、理化特性、VEGF及受体在眼内血管新生中的作用以及针对血管新生的防治措施进行综述.     

糖尿病视网膜病变患者血清中血管内皮生长因子和色素上皮衍生因子水平的变化

糖尿病视网膜病变(DR)基本病理改变是血视网膜屏障破坏,新生血管形成.血管内皮生长因子(VEGF)是促进血管生成的重要因子之一,通过促进内皮细胞增生,改变细胞外基质及增加血管通透性促进血管新生.色素上皮衍生因子(PEDF)可以通过抑制炎症以及氧化应激反应,促进内皮细胞凋亡等抑制新生血管形成.为了解VEGF与PEDF水平在DR发生发展过程中的变化,我们对一组糖尿病患者和DR患者的血清VEGF与PEDF进行了测定,现将结果报道如下.     

血管内皮生长因子及其受体与眼内新生血管性疾病

眼内新生血管性疾病是致盲的主要原因之一，vEGF是主要的血管生成因子，许多生长因子是通过诱导vEGF的表达而起作用的。对vEGF及其受体与眼内新生血管性疾病的关系和针对其作用机制采取的抗眼内新生血管形成的措施进行综述。     

β肾上腺素能受体拮抗剂治疗眼部新生血管疾病的研究进展

眼部新生血管形成是糖尿病视网膜病变、早产儿视网膜病变、视网膜中央静脉阻塞和老年性黄斑变性等多种眼部疾病的病理学改变, 严重影响患者视力。β受体在结膜、角膜上皮细胞、角膜内皮细胞、眼外肌、小梁网、睫状肌、晶状体和视网膜中均有表达。β肾上腺素能受体拮抗剂与β受体结合, 通过抑制血管内皮生长因子(VEGF)、缺氧诱导因子-1、白细胞介素-6等促血管生成细胞因子, 降低巨噬细胞相关炎症反应, 增加抗血管生成因子表达来发挥抗血管生成作用。其在治疗角膜新生血管、脉络膜新生血管、早产儿视网膜病变时, 可显著减少新生血管面积, 延缓疾病进展, 联合应用抗VEGF药物可减少抗VEGF药物的给药频率。在有效的治疗浓度下, β肾上腺素能受体拮抗剂表现出良好的耐受性;且其较抗VEGF药物有更广泛的靶点, 为角膜、脉络膜和视网膜新生血管等眼部新生血管性疾病提供了新的治疗策略。     

β肾上腺素能受体拮抗剂治疗眼部新生血管疾病的研究进展

眼部新生血管形成是糖尿病视网膜病变、早产儿视网膜病变、视网膜中央静脉阻塞和老年性黄斑变性等多种眼部疾病的病理学改变,严重影响患者视力。β受体在结膜、角膜上皮细胞、角膜内皮细胞、眼外肌、小梁网、睫状肌、晶状体和视网膜中均有表达。β肾上腺素能受体拮抗剂与β受体结合,通过抑制血管内皮生长因子（VEGF）、缺氧诱导因子-1、白...     

血管内皮生长因子受体与眼新生血管及增生性病变

血管内皮生长因子（VEGF）是一种特异性刺激血管内皮细胞增殖和新生血管形成的生长因子,是最直接的血管内皮细胞促分裂素,与血管内皮生长因子受体（VEGFR）结合而发挥各项功能。在视网膜细胞、色素上皮细胞、表皮细胞、M(?)ller细胞内均有VEGFR表达。缺氧可上调其基因表达,直接造成视网膜新生血管形成及增生性玻璃体视网膜病变。对VEGFR结构、功能、与新生血管的关系,VEGFR表达增高所导致的病理变化,VEGFR高表达的调节因素,如何抑制VEGFR阻断VEGF/VEGFR信号传导途径抑制VEGF作用等方面进行了较为全面的综述。     

RNA干扰治疗脉络膜新生血管

脉络膜新生血管(CNV)是许多威胁视力的眼病的主要并发症。血管内皮生长因子(VEGF)是功能最强的血管形成促进因子,能促进CNV的形成。VEGF抑制因子成为目前抑制CNV的研究重点。RNA干扰(RNA interfering,RNAi)可抑制VEGF表达,从而抑制CNV。本文对CNV目前治疗现状、存在的问题和RNAi通过抑制VEGF表达对CNV的治疗作用及其机制作一综述。     

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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Effects of Adenosine Agonists on Intraocular Pressure and Aqueous Humor Dynamics in Cynomolgus Monkeys

The effects of single or multiple topical doses of the relatively selective A₁adenosine receptor agonists (R)-phenylisopropyladenosine (R-PIA) and N⁶-cyclohexyladenosine (CHA) on intraocular pressure (IOP), aqueous humor flow (AHF) and outflow facility were investigated in ocular normotensive cynomolgus monkeys. IOP and AHF were determined, under ketamine anesthesia, by Goldmann applanation tonometry and fluorophotometry, respectively. Total outflow facility was determined by anterior chamber perfusion under pentobarbital anesthesia. A single unilateral topical application of R-PIA (20–250 μg) or CHA (20–500 μg) produced ocular hypertension (maximum rise=4.9 or 3.5 mmHg) within 30 min, followed by ocular hypotension (maximum fall=2.1 or 3.6 mmHg) from 2–6 hr. The relatively selective adenosine A₂antagonist 3,7-dimethyl-1-propargylxanthine (DMPX, 320 μg) inhibited the early hypertension, without influencing the hypotension. Neither 100 μg R-PIA nor 500 μg CHA clearly altered AHF. Total outflow facility was increased by 71% 3 hr after 100 μg R-PIA. In conclusion, the early ocular hypertension produced by topical adenosine agonists in cynomolgus monkeys is associated with the activation of adenosine A₂receptors, while the subsequent hypotension appears to be mediated by adenosine A₁receptors and results primarily from increased outflow facility.