视网膜特异性表达人血管内皮生长因子 基因载体的构建

目的构建在视网膜组织特异性表达的人血管内皮生长因子（VEGF）₁₆₅基因。方法用聚合酶链反应(PCR)方法从BLAB/C鼠全基因组扩增能在视网膜组织特异性表达的rho启动子，经限制性内切酶纯化后克隆于质粒pcDNA^3.1+-VEGF₁₆₅中，建立重组质粒pcDNA^3.1+-rho-VEGF₁₆₅，通过限制性内切酶酶切分析及PCR鉴定筛选出正确重组质粒pcDNA^3.1+-rho-VEGF₁₆₅,由jetPEI介导转染人视网膜色素上皮细胞和人脐静脉内皮细胞，并通过免疫组织化学染色以及绘制细胞生长曲线检测在人视网膜色素上皮细胞和人脐静脉内皮细胞中VEGF蛋白的表达。结果在人视网膜色素上皮细胞中，重组质粒pcDNA^3.1+-rho-VEGF₁₆₅比质粒pcDNA^3.1+-rho-VEGF₁₆₅的VEGF蛋白表达强，在人脐静脉内皮细胞，两者的表达量无明显差别。结论pcDNA^3.1+-rho-VEGF₁₆₅载体的构建为进一步研究VEGF在视网膜新生血管形成中的致病机理提供基础材料，并为进一步建立视网膜特异性表达VEGF转基因鼠模型建立了基础。(中华眼底病杂志,2005,21:106-109)     

Effect of morphological abnormalities on blood retinal barrier permeability in diabetic retinopathy

The morphological base for the impaired function of the blood retinal barrier was studied in 50 eyes of 10 insulin dependent and 21 non-insulin dependent patients with various levels of diabetic retinopathy. The permeability of the blood retinal barrier (P_BRB) was determined by vitreous fluorophotometry with correction for autofluorescence, lenstransmission and non-protein bound plasma fluorescein concentration. Morphological abnormalities of diabetic retinopathy assessed by fundus photography and fluorescein angiography were individually scored on a decimal scale and related to the P_BRB by multiple regression analysis. The P_brb was not correlated to morphological abnormalities of non-proliferative retinopathy [(1) microaneurysms, (2) hard exudates, (3) soft exudates, (4) intraretinal hemorrhages, (5) fluorescein leakage, and (6) capillary closure, p > 0.3]. The P_BRB was correlated to morphological abnormalities of (pre)proliferative retinopathy [(1) intraretinal microvascular abnormalities (S_irma) and (2) new vessels (S_neo): p_brb = A – B.S_IRMA – C.S_neo with P_BRB in nm/sec, A = 1.5 ± 0.5, B = 0.9 ± 0.2 and C = 1.7 ± 0.4, R² = 0.65, p < 0.0001]. It can be concluded that the increased blood retinal barrier permeability in diabetic patients is mainly due to (pre)proliferative abnormalities and not to non-proliferative abnormalities.     

血管内皮生长因子在糖尿病大鼠视网膜中的表达

目的 :利用糖尿病大鼠动物模型 ,通过大鼠视网膜中血管内皮生长因子 ( vascular en-dothelial growth factor,VEGF)的表达情况 ,探讨 VEGF在糖尿病视网膜病变 ( diabetic retinopa-thy,DR)发展过程中作用机理。方法 :复制链脲佐菌素 ( streptozocin,STZ)糖尿病大鼠动物模型 ,取不同组、不同时期大鼠视网膜 ,利用免疫组织化学及原位杂交方法 ,检测 VEGF蛋白质及 m RNA的表达情况。结果 :1正常对照组 ( M)、血糖恢复组及糖尿病 1个月组 ( M1)大鼠视网膜均无 VEGF蛋白质及 m RNA的阳性表达 ;2糖尿病 3个月组 ( M3 )未见 VEGF m RNA表达 ,而在内核层及节细胞层有 VEGF蛋白表达阳性 ( 34%) ,此表达与胶质纤维酸性蛋白 ( GFAP)染色阳性细胞相同 ;3糖尿病 5个月组 ( M5) VEGF m RNA表达阳性率为 67%,表达位于视网膜各层 ,内界膜中的表达与 GFAP免疫组化阳性分布相同 ,VEGF蛋白质表达强阳性 ( 89%) ,主要位于内核层、节细胞层的细胞及血管上。结论 :VEGF在 STZ大鼠视网膜中的表达与病程相关 ,而且 VEGF的产生存在着自分泌和旁分泌多种途径     

Pathogenesis of diabetic retinopathy and the renin-angiotensin system.

Despite the beneficial effects of good glycaemic control, loss of vision because of diabetic retinopathy (DR) still occurs. Recent studies have suggested that hypertension is a risk factor for the development and progression of DR and that blood pressure reduction can delay the progression of retinopathy. The renin-angiotensin system is activated by chronic hyperglycaemia, and the vitreous fluid level of angiotensin II (AII) is elevated in patients with proliferative diabetic retinopathy and diabetic macular oedema. AII increases vascular permeability and promotes neovascularization. It has been suggested that an autocrine-paracrine relationship may exist between AII and vascular endothelial growth factor in the ocular tissues. Accordingly, angiotensin-converting enzyme inhibitors or AII Type 1 (AT1) receptor blockers may be useful therapeutic agents for preventing the progression of DR.     

急进性后极部早产儿视网膜病变的临床进程及疗效观察

目的 描述急进性后极部早产儿视网膜病变(AP-ROP)的临床进程及特征,评价视网膜光凝及冷凝对急进性后极部早产儿视网膜病变的治疗效果.方法 前瞻性、非对比性、连续性病例.2006年1月至2008年6月经检查确诊为急进性后极部ROP的患儿8例16只眼.确诊后24h内行间接眼底镜下行视网膜光凝治疗联合或不联合直视下冷凝治疗.结果 急进性后极部早产儿视网膜病变以病变大部分位于后极部1区,所有象限视网膜血管扩张迂曲,病程进展快,若不及时治疗,迅速发生视网膜漏斗状全脱离为临床特征.本组8例16只眼视网膜光凝和(或)冷凝治疗后,9只眼病变完全退化或控制,占56.2%.7只眼病情未能控制,最终发展为4b至5期视网膜病变.结论 AP-ROP进展快,预后不良,部分患儿虽经严密观察和治疗,病情仍进展.视网膜光凝和(或)冷凝治疗能控制大部分AP-ROP患儿视网膜病变的发展,挽救患儿视功能.临床上需要加强观察和随访,早发现、早诊断、早治疗是减低该病致盲率的惟一方法.     

以新生儿重症监护病房为中心的早产儿视网膜病变筛查模式

目的：介绍一种较为完善的早产儿视网膜病变（ROP）筛查模式。方法：建立基本完善的ROP登记、会诊、筛查、转诊等制度,所有工作均在新生儿重症监护病房（N ICU）完成,形成以NICU为中心的ROP筛查模式,并按此模式开展筛查工作。结果：登记符合ROP筛查标准的患儿239例,其中接受至少一次筛查的患儿222例（占应筛查总数的92.89%）,按要求完成筛查的患儿176例（占应筛查总数的73.64%）。发现ROP患儿39例（占实际筛查数的17.57%）,其中阈值前期1型或阈值期病变11例（占实际筛查数的4.96%）。结论：这种以NICU为中心的ROP筛查模式,制度较为完善,临床中易于操作,能有效节约医疗资源,适合在中小城市中推广。     

Measuring oscillatory potentials: Fourier analysis

Studying the oscillatory potentials in diabetic retinopathy, the authors experienced several problems interpreting results of digital filtering. The main problem was the separation of the first potential from the a-wave, since their frequencies are within the same range. To improve the procedure of measuring implicit times and of calculating amplitudes, the filtering was started with a finite impulse response filter and followed by a fast Fourier transform. The power of the oscillatory potential was calculated by determining the dominant frequency in the Fourier transformed response and expressed in microwatts. A group of normal subjects was compared with a group of early diabetic retinopathy patients. It appears that even in pathological circumstances a quantitative expression of the oscillatory potential is possible.     

裂隙灯致视网膜损伤的眼底实验观察与阈值探讨

本文用苏州产裂隙灯对3只猕猴双眼黄斑周围视网膜共36个部位进行随机持续光照,视网膜辐照度为226.8mW/cm~2。照射时间分别为30、45、60、90、120、150、180min。用检眼镜、眼底荧光血管造影对光照即刻到2个月的受照区视网膜进行观察。结果:持续光照120min以上,出现视网膜损伤。经统计学计算,本文提出:裂隙灯使用的相对安全时间阈值为98min。并提出多部位投照方法。