视网膜是一种高度专业化的组织,具有独特的结构及适应性,在所有不同类型的视网膜细胞中保持动态平衡对于维持视力至关重要.视网膜可能会暴露在各种环境损伤中,如光诱导的损伤,在进化过程中,视网膜细胞对各种损伤产生了适应性反应,这些反应共同恢复了细胞的动态平衡,并增加了组织对进一步损伤的抵抗力.然而过度光照则会导致视网膜组织内光感受器细胞、视网膜神经节细胞(RGC)、视网膜神经胶质细胞及视网膜色素上皮细胞(RPE)发生一系列病理改变,包括线粒体内活性氧(ROS)和Ca2+浓度增加、细胞凋亡、内质网应激、细胞自噬和炎症等,从而导致视网膜发生不可逆损伤.本文将对视网膜光损伤的发病机制和相关研究进展进行详细阐述,为未来防治视网膜光损伤提供研究方向.

突发事件会打乱人们的学习、工作和生活节奏,同时也给医学留学生的教育及临床培训带来了严峻的挑战.在这种情况下,医学远程教育的应用改善了教学过程,提供了更多学习医学课程的机会,扩大了临床实践,对医学生有极大的益处.医学远程教育模式的探索中需要针对目前存在的问题不断改革、完善与创新,开发和使用基于技术及模拟的创新教育模式及方法,提高留学生感知度、易用性以及参与积极性,从而进一步提升教学质量和学习效果,培养合格的医学人才.

Background: Diabetic retinopathy (DR) is a serious complication of diabetes that can lead to blindness. This study aimed to identify the core genes and molecular functions involved in DR through multiple bioinformatics analyses. Material/Methods: The mRNA gene profiles of human DR tissues from the GSE60436 and GSE53257 datasets were assessed with R software and integrated to identify the co-expressed differentially expressed genes (DEGs). Multiple bioinformatics analyses were used: Gene Ontology (GO) analysis, signaling pathway analysis, and hub gene prediction. Quantitative reverse transcription-PCR (qRT-PCR) was used to verify the hub genes. Results: The Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool suggested that the biological processes of the DEGs focused on mitochondrial transport, the cellular components focused on mitochondria, and molecular functions focused on catalytic activity. The results provided by DAVID were consistent with those provided by STRING and the GeneMANIA online database. All the DEGs function in metabolic pathways, consistent with the g: Profiler online analysis results. The protein-protein interaction (PPI) networks forecasted by STRING and GeneMANIA were entered into Cytoscape for cytoHubba degree analysis. The hub genes predicted by cytoHubba suggested that fumarate hydratase (FH) might be relevant to DR. qRT-PCR suggested that the expression of FH was higher in DR retinal tissues than in normal control tissues. Conclusions: Multiple bioinformatics analyses verified that FH could be used as a potential diagnostic marker and new therapeutic target of DR.

INTRODUCTION:Retinitis pigmentosa (RP) caused by the photoreceptor cell degeneration is currently incurable and leads to partial or complete blindness eventually. 3,5-dimethoxy-4-hydroxy myricanol (DM) is a novel compound isolated from the leaves of Micromelum integerrimum, with proliferative activities on NIH3T3 cells. This study was to investigate whether DM could mitigate retinal degeneration of rd10 mice, a well-characterized mouse model of RP.MATERIALS AND METHOD:Rd10 mice were treated with DM daily by intraperitoneal injection from postnatal day 12 (P12) to P26. Electroretinography (ERG) reflects the mass response of photoreceptor cells and was used to test the outer retinal function after DM treatment. Haematoxylin and Eosin staining was used to show the retinal morphology and evaluate the rod photoreceptor cell loss. TUNEL assay was used to detect the apoptosis-positive cells. Inflammatory factors were measured by ELISA to show the inflammatory response. Real-time PCR and western blot were applied to measure the gene and protein change to explore the underlying mechanisms.RESULTS:Results showed that DM significantly improved the retinal function by increasing the ERG amplitude, preserving the retinal morphology, reducing photoreceptor cell apoptosis, decreasing inflammatory response, and inhibiting endoplasmic reticulum stress in rd10 mice.CONCLUSION:This is the first time when the protective effects of DM against photoreceptor cell degeneration of rd10 mice have been demonstrated, providing scientific rationale to develop DM as a potential agent to treat RP.

目的观察蛋白质粒转染大鼠视网膜干细胞后蛋白的表达及细胞生长、分化情况。方法应用机械-酶消化法将出生10d大鼠的睫状体组织制成单细胞悬液,并应用含20μg/L表皮生长因子、20μg/L碱性成纤维细胞生长因子和1×B27添加剂在无血清DMEM/F12培养基中培养。取第2代细胞应用免疫细胞化学染色检测神经干细胞特异性抗原神经巢蛋白（nestin）及细胞分裂增殖标志物5-溴脱氧尿核苷（5-bromodeoxyuridine,BrdU）的表达。应用脂质体转染法将含有绿色荧光蛋白（green fluorescent protein,GFP）的质粒pGCsilencerTM U6/Neo/GFP转染到RSCs内,转染后应用荧光显微镜观察细胞生长情况,转染后应用G418筛选,一周后对转染后的细胞应用含50ml/L的胎牛血清的培养基进行诱导分化,并应用免疫细胞化学染色方法对于分化后的细胞进行神经元标志物神经元特异性烯醇酶（neurone specific enolase,NSE）、神经胶质细胞标志物神经胶质酸性蛋白（glial fibrillary acidic protein,GFAP）检测。结果原代细胞培养2d后在培养基内可以观察到悬浮的折光性强的小细胞团,4-5d后细胞团数量增多且体积变大,7-9d后细胞传代,应用免疫细胞化学方法可检测到细胞表达神经标志物nestin及增殖标志BrdU,基因转染1d后即可在细胞内观察到荧光的表达,于转染2-3d后荧光逐渐增强并可维持较长时间。筛选一周时细胞基本均表达GFP。转染后细胞的生长特性未发生明显变化,在以血清为诱导条件下仍可分化出神经样细胞。诱导第7日免疫化学染色分别检测出神经元及胶质细胞标志物NSE及GFAP的表达。结论来源于睫状区的大鼠视网膜干细胞经基因转染后可在一定时间内稳定表达,并且细胞增殖及分化未受到明显影响,实验为下一步进行RSCs内表达或抑制特定的目的基因的实验研究奠定了基础。

AIM:To observe the efficiency of cultivation of retinal stem cells (RSC)in vitro by tissue cultivation method. ·METHODS:The tissue of ciliary body of postnatal 10 days rat was isolated and divided into small bits,then cultivated with non-serum DMEM/F12 medium,20μg/L bFGF,20μg/L EGF and 1×B27 supplement at the same time,the embryonic brain derived neural stem cells (NSC) were isolated and cultivated with routine method as positive control. These two kinds of cells were identified by detection of nestin with immunofluorescence method,which was known as a marker of neural stem cells. The characteristic of differentiation of RSC was identified in the induced condition of 100mL/L FBS medium. ·RESULTS:In the primary cultivation,cell spheres with high refraction were observed 48 hours after isolation and cultivation. The cell spheres enlarged and the amount increased gradually in the fourth or fifth day of cultivation. The passage of the cells occurred in the seventh day of cultivation,and the cells of the next passage can also formed the sphere shape. The marker nestin was detected both in RSC and NSC by immunofluorescence method. The RSC became adherent with the bottom of the culture dish in the induced condition with serum,and some of the cells differentiated into cells with neural cell shapes. The characteristics of the shape,proliferation and differentiation of RSC were similar with NSC. ·CONCLUSION:Tissue cultivation has the characteristics of less damage and convenience,which can be used in the isolation and cultivation of RSC successfully.

Objective To study the effect of growth associated protein -43(GAP-43) expression in retinal development of neonate rat and differentiation of bone marrow mesenchymal stem cells(BMSC) to retinal ganglion-like cells induced by retinal cells in vitro.Methods Retinal cells of neonate rat with 3 days old were cultivated to detect GAP-43 expression by immunocytochemistry,the total RNA of retinal cells were extracted and GAP-43 mRNA expression were detected by RT-PCR.BMSC were cultivated in vitro and passaged to the 3rd generation,the surface maker of BMSC were identified by flow cytometer.BMSC were induced and differentiated by co-cultivation with retinal cells of neonate rat.Morphological changes of induced cells were observed,and NSE,nestin,GAP-43,and thy1.1 of induced cells were detected by immunocytochemistry after co-cultivation on the 5th day.Results Positive expression of GAP-43 could be detected by immunocytochemistry in cultivated retinal cells of neonate rat,and GAP-43 mRNA expression also could be found in retina of neonate rat by RT-PCR.The 3rd generation of BMSC were identified with CD71(+),CD29(+),CD34(-),and CD45(-) by flow cytometer.BMSC could be induced and differentiated into retinal ganglion-like cells by co-cultivation with retinal cells of neonate rat,which was proved that the expression of NSE,thy1.1,nestin and GAP-43 were positive.The positive expression of GAP-43 mRNA could be detected in retinal ganglion-like cells after differentiation.Conclusion GAP-43 not only participates in the retinal development of neonate rat,but also plays an important role in the differentiation of BMSC to retinal ganglion-like cells induced by the retinal cells of neonate rat.

Objective To summarize therapeutic efficacy of scleral buckling with optical fiber in retinal detachment of silicone oil-filled eyes.Methods we retrospectively studied the clinical materials of 12 patients(12 eyes)who suffered retinal detachment in their silicone oil-filled eyes and undergone scleral buckling with optical fiber in the second hospital.Results retina were re-attachment in 11eyes(91.7%)after scleral buckling operation with optical fiber.There were 8 eyes in our cases maintained retina attachment even after silicone oil was taken out.All the eyes maintained visual acuity in some degree,the visual acuity of 4 eyes(33.3%1 were above 0.1.Conclusions scleral buckling therapy with optical fiber can be effective to retinal detachment of silicone oil-filled eyes in such cases as localized detachment,slight anterior PVR,defined retinal hole,retinal hole before scleral equator,inferior hole,superior retinal hole with hard rim.

Objective To observe growth associated protein-43(GAP-43) expression on the differentiation of bone marrow mesenchymal stem cells(BMSCs) to neuron-like cells in vitro in order to understand it's effect on this process.Methods BMSCs of rat were isolated and cultivated in vitro,the purified BMSCs of the third generation were identificated by flow cytometer.BMSCs were induced and differentiated by beta mercaptoethanol(BME) and brain-derived neurotrophic factor(BDNF),respectively.Morphological changes of induced cells were observed,and GAP43,nestin,NSE and NF of induced cells in two groups were detected by immunocytochemistry.The positive rates of GAP-43 staining in two groups were compared by statistic method on 2,4,6,8 hours after induction respectively.Results The third generation BMSCs were identificated with CD90(+),CD71(+),CD29(+),and CD45(-) by flow cytometer.BMSCs can be induced to differentiate into neuronlike cells by BME and BDNF respectively.The induced cells expressed GAP-43、nestin、NSE、NF.On 2,4,6,8 hours after induction,the positive rates of GAP-43 were 77.1%,83.4%,87.0%,82.5% in BME group,and 69.3%,78.1%,82.2%,86.8% in BDNF group respectively.BMSCs expressed GAP-43 persistently after induction in both two groups.There were no significant differences between two groups in positive rates of GAP-43 staining(P 0.05).Conclusion GAP-43 can express persistently in the process that BMSCs are induced to differentiate into neuron-like cells by either chemical inducer or neurotrophic factor,and play a important role in this process.

Objective To discuss the clinical therapeutic effect of acute retinal necrosis(ARN) after integrated therapy.Method We reviewed retrospectively the clinical materials of 15 patients(17 eyes) with ARN who underwent integrated therapy(drugs,laser and vitrectomy).Results Out of the 17 eyes,5 eyes showed stability after drugs and laser therapy,while retinal detachment was found in other 12 eyes and vitrectomy was carried out on 10 eyes and 8 eyes obtained anatomic success after surgery.40.7% eyes with ARN maintained ambulatory vision(0.1 or better) finally after integrated therapy.Conclusion Immediate integrated therapy can effectively control the procession of the disease and rescue the visual function.

Objective To explore the causes, method selection and effects of reoperation about failed operation and recurrence of rhegmatogenous retinal detachment. Method We analyzed 59 cases(60 eyes) of RRD retrospectively, whose retina couldn't be retached or redetached after episcleral buckling surgery, and needed reoperation. Results The visual acuity showed no significant differences after first and second surgery(P0.05), and the grades of proliferative vitreoretinopathy (PVR) before second surgery were significantly severer than that of first surgery(P0.05). The reasons that caused failed operation and early recurrent retinal detachment of RRD were progressive vitreoretinal traction with PVR, formation of new retinal breaks, reopening of original breaks, and the reasons that lead to later recurrent retinal redetachment were the vitreoretinal traction of vitreous bases. Conclusion The key to operative success are searching ocular fundus carefully before operation and buckling all of the retinal breaks during operation. Episcleral buckling surgery is also the main method of reoperation. Vitrectomy should be applied when PVR is seriously. The majority of patients' retina could be retached after reoperation.