Circulating serum fibroblast growth factor 21 as risk and prognostic biomarker of retinal artery occlusion.

To evaluate the predictive and prognostic value of fibroblast growth factor 21 (FGF21) levels in retinal artery occlusion (RAO) patients. In this case-control study, serum FGF21 levels were detected by using the ELISA method. Multivariable logistic regression analyses were performed to evaluate the significance of FGF21 in assessing the risk of developing RAO and its impact on vision and concurrent ischemic stroke. Compared with control group, serum FGF21 levels were significantly higher (median [IQR] = 230.90[167.40,332.20] pg/ml) in RAO patients. Multivariate logistic regression analysis showed that elevated serum FGF21 levels were associated with a higher risk of RAO occurrence (P = 0.025, OR [95%CI] = 9.672 [2.573, 36.359]) after adjustment for multiple confounding factors. Higher serum FGF21 levels were negatively associated with visual acuity improvement (P = 0.029, OR [95%CI] = 0.466[0.235, 0.925]) and positively correlated with concurrent ischemic stroke (P = 0.04, OR [95% CI] = 1.944[1.029, 3.672]) in RAO patients. Elevated serum FGF21 levels could promote the development of RAO and indicate worse visual prognosis and increase the risk of concurrent ischemic stroke, which might help clinicians early diagnose and treat RAO patients.

Clinical application of multicolor scanning laser ophthalmology in diagnosis and grading of central retinal artery occlusion.

Purpose: To characterize features of central retinal artery occlusion (CRAO) using multicolor (MC) imaging and to assess the differences in CRAO grading between color fundus photography (CFP) and MC image qualitatively and quantitatively. Methods: We conducted a prospective, cross-sectional study in the Department of Ophthalmology of Renmin Hospital of Wuhan University. In total, 86 acute CRAO patients were included. Spectral-domain optical coherence tomography (SD-OCT), CFP, and MC examinations were taken at baseline. Based on the findings of these three examinations, CRAO was divided into three grades (incomplete, subtotal, and total). Based on OCT grading criteria, we qualitatively compared the ability of grading CRAO by CFP and MC. CRAO patient's visual acuity (VA) was obtained from the initial visit. The retinal thickness was measured by SD-OCT. Superficial capillary plexus (SCP) and deep capillary plexus (DCP) were obtained from optical coherence tomography angiography (OCTA) examinations. Quantitative data were compared across the three acute CRAO subgroups and against three examination findings. Results: MC image had significantly higher power of acute CRAO detection than CFP (P = 0.03). In the same group of CRAO patients, there was no significant difference in VA when comparing OCT with the MC grading system or with the CFP grading system (all P > 0.05). Significant differences in VA were found between the three CRAO subgroups only under MC grading (P = 0.016). In incomplete CRAO patients, significant differences were found in central fovea thickness (CFT) when comparing OCT with the CFP grading system (P = 0.019). In the same group of CRAO patients, there was no significant difference in retinal thickness when comparing OCT with the MC grading system (All P > 0.05). Significance differences in CFT (P < 0.001), innermost retinal layer (IMRL; P < 0.01), middle retinal layer (MRL; P < 0.001), and outer retinal layer (ORL; P = 0.021) were found between the three CRAO subgroups by MC grading. Vessel density of SCP showed a statistically increased as the severity of three CRAO subgroups (P = 0.03), whereas DCP did not have significant differences (P = 0.745). Comparisons were made between the OCT grading method and the MC and CFP grading methods; there is no significant difference in vessel density of SCP and DCP (All P > 0.05). Conclusion: The images obtained by MC are superior to those obtained by CFP in CRAO grading, retinal thickness, and vessel density measurement. MC imaging may be more capable of CRAO grading than OCT. We recommend MC imaging to determine CRAO severity to guide disease treatment and predict visual prognosis.

Ochratoxin A induces mitochondrial dysfunction, oxidative stress, and apoptosis of retinal ganglion cells (RGCs), leading to retinal damage in mice.

PURPOSE: Ochratoxin A (OTA) contamination of food and feed is a serious problem worldwide. OTA is considered a carcinogen and immunotoxic, nephrotoxic, and neurotoxic mycotoxin. The present study aims to determine the toxic effects of OTA on retinal ganglion cells (RGCs) and assess the resulting impairment of retinal function in mice. METHODS: RGC-5 cells were exposed to OTA (100 and 200 µg/L) for 3 days, and the mice were fed OTA-contain (100 and 200 µg/kg) diets for 4 weeks. Antioxidant indices were detected by spectrophotometer. The apoptosis of RGC-5 cells was determined by flow cytometry. Mitochondrial morphology and mitochondrial membrane potential were detected by immunofluorescence. RGC survival was determined by immunofluorescence staining with Brn3a. Flash electroretinography (ERG) was conducted to assess visual function. RESULTS: The oxidative-antioxidant balance suggested that OTA-induced severe oxidative stress, including increased reactive oxygen species (ROS) and malondialdehyde (MDA) levels in the OTA-exposed RGC-5 cells, and the reduced activity of superoxide dismutase (SOD) and glutathione-S-transferase (GST) in the OTA exposed group. Furthermore, OTA exposure led to remarkable apoptosis in RGC-5 cells. The mitochondrial detection showed that OTA caused significant mitochondrial membrane potential reduction and mitochondrial fragmentation, which may be the cause of apoptosis of RGC-5 cells. Additionally, in vivo experiments demonstrated that OTA resulted in significant death of RGCs and subsequent retinal dysfunction in mice. CONCLUSION: Ochratoxin A induces mitochondrial dysfunction, oxidative stress, and RGCs death in mice.

Improved visual outcomes of central retinal artery occlusion with local intra-arterial fibrinolysis beyond the conventional time window.

Local intra-arterial fibrinolysis (LIF) is a promising therapeutic option for CRAO. However, the narrow time window of 6 h has greatly limited the application of LIF. In this study, we explored the efficacy of LIF beyond the conventional time windows and compared the result with conservative therapy. This prospective study included 179 CRAO patients with baseline visual acuity (VA) ≤ 20/400 treated at Renmin Hospital of Wuhan University. The mean time from vision loss to presentation was 5.5 days. 58 patients received conventional standard therapy (CST) alone.121 patients underwent LIF. Main outcome was VA improvement ≥ 0.3 logMAR. Secondary outcome was a favorable VA outcome of 20/200 or better. Logistic regressions were performed to identify predictors of visual improvement. 43% patients in the LIF group experienced VA improvement versus 19% with CST (P = 0.002). LIF was associated with 4.0-fold higher likelihood of visual improvement compared to CST (P = 0.001). Poor baseline VA (light perception or no light perception) and shortened prothrombin time (PT) were associated with greater chance of visual improvement with LIF. However, LIF showed no significant advantage over CST for favorable VA outcomes. No major complications occurred. LIF beyond the therapeutic time window improved vision in functionally blind CRAO patients and showed better efficacy when compared with CST. PT may be a potential predictor of visual outcome after LIF. Our findings could complement existing time-based treatment guidelines and potentially allow for personalized decisions on the use of LIF beyond time windows.

Application progress of human amniotic membrane in vitreoretinopathy: a literature review.

Recently, the application of the amniotic membrane (AM) in ophthalmology is gradually expanding from the anterior to the posterior segment of the eye. Its characteristics of anti-inflammation, anti-bacterial, anti-vascularization, immune regulation, anti-fibrosis, pro-epithelialization, and so forth have made it a hot topic in ophthalmic research. AM has been confirmed to repair photoreceptors, restore normal retinal structures, and close the abnormal structures in the optic disc. Currently, the application areas mainly include retinal hole, retinal detachment, optic disc pit, retinal degenerative diseases, and choroidal hole. This article reviews the current literature applying AM transplantation in the treatment of various posterior segment diseases while comparing the clinical outcomes with other techniques.

The diagnostic utility of nanopore targeted sequencing in suspected endophthalmitis.

PURPOSE: This paper aimed to assess the diagnostic utility of a newly developed gene-based technology-nanopore targeted sequencing (NTS) in suspected endophthalmitis patients. METHODS: This retrospective study included 43 patients (44 eyes) with suspected endophthalmitis. NTS was applied along with microbiological culture to detect unknown pathogens in intraocular fluid samples. The diagnostic utility of NTS was mainly evaluated from three aspects, including the positivity rate of bacterial/fungal presence, diagnostic turnaround time and the frequency of change in treatment based on etiology test results. Non-parametric, two-sided Wilcoxon rank sum test, the McNemar's test and the kappa statistic were used for statistical comparisons. RESULTS: NTS showed significant advantages over traditional culture in positivity rates and diagnostic time (P < 0.001, kappa = 0.082; Z = -5.805, P < 0. 001). As regards antibiotic strategy, 17 patients (39.53%) and 5 patients (11.63%) underwent medication change following NTS and culture results respectively (P < 0.001, kappa = 0.335). With reasonable use of antibiotic and surgical intervention, most patients responded favorably, judged by significantly improved visual acuity (Z = -4.249, P < 0.001). The mean duration of hospitalization was 8.49 ± 2.45 days (range, 1-16 days). CONCLUSION: The high efficiency feature of NTS in pathogen detection renders it a valuable supplementary to traditional culture. Additionally, it has facilitated patients' management for the early and precise diagnosis of endophthalmitis.

IDENTIFICATION OF PATHOGENS IN THE INTRAOCULAR FLUID SAMPLES OF PATIENTS WITH ENDOGENOUS ENDOPHTHALMITIS USING RAPID NANOPORE TARGETED SEQUENCING.

IN BRIEF: Nanopore targeted sequencing showed a higher positivity rate and a shorter turnaround time than did traditional culture in identifying pathogens in the intraocular fluid samples of patients with endogenous endophthalmitis. PURPOSE: To evaluate the feasibility of clinical application of nanopore targeted sequencing (NTS) for the identification of pathogens in patients with endogenous endophthalmitis, especially those with fungus-associated endophthalmitis. METHODS: In this retrospective study, medical records and etiological results of 27 patients (34 eyes) with endogenous endophthalmitis were reviewed. The intraocular fluid samples were examined using both NTS and microbial culture. The results included the differences in detection time, positivity rate of pathogen detection, and positivity rate of fungus identification between two methods. RESULTS: NTS and microbial culture enabled the detection of etiologic agents in 89.28% and 35.71% of the samples, respectively. The difference of positivity rate between these methods was statistically significant ( P < 0.001). NTS also showed high sensitivity in both culture-positive and culture-negative samples (100% and 83.33%, respectively). Regarding culture-positive samples, the NTS results displayed a strong match with culture results. NTS showed a significantly higher positivity rate for fungal infection than did microbial culture (46.43% vs. 7.14%, P = 0.002). The average detection time of NTS was 1.11 ± 0.31 days, which was shorter than that of microbial culture (2.50 ± 0.58 days, Z = -4.686, P < 0.001). NTS technology facilitated an informed switch of intravitreal antimicrobial agents in 13 eyes. CONCLUSION: NTS, as a sensitive, specific, and timely complementary method, can be used along with traditional methods for the identification of pathogenic microorganisms in the intraocular fluid of patients with endogenous endophthalmitis.

The involvement of ACO3 protein in diabetic retinopathy through the PI3k/Akt signaling pathway.

BACKGROUND: Diabetic retinopathy (DR) is one of the most common complications of diabetic microvascular disease and its pathogenesis is complicated. The PI3k/Akt signaling pathway plays an important role in the angiogenesis of DR. OBJECTIVES: To explore the molecular mechanisms of the ACO3 protein and related proteins in DR, in order to provide a scientific theoretical basis for the clinical treatment of this disease. MATERIAL AND METHODS: A DR rat model was used in this study. One group (anti-ACO3 group, n = 10) was injected with protein ACO3 antagonist; the 2nd study group (the DR group, n = 10) was injected with the same amount of normal saline; the control group (n = 10) did not undergo any procedures. We used hematoxylin and eosin (H&E) staining to observe the pathological features of the eye tissues. Immunohistochemistry was used to analyze the expression of ACO3 and AKT. Western blot was used to analyze the expression of ANGPT1, ANGPT4 and KDR; reverse transcription polymerase chain reaction (RT-PCR) was used to assess the mRNA expression of AKT, ACO3 and SMOX in the eye tissues of the rats. RESULTS: In the anti-ACO3 group, the results of H&E staining showed that there was a decrease in retinal edema and no obvious abnormality in the blood vessels. The immunohistochemistry analysis of proteins proved that ACO3 and AKT were strongly expressed in the DR group. The western blot analysis of ANGPT1, ANGPT4 and KDR expression showed that in the DR group, the expression of all 3 proteins was higher than in the anti-ACO3 group, and much higher than in the control group. CONCLUSIONS: The mRNA expression of AKT, ACO3 and SMOX was strong in the DR group, but decreased in the anti-ACO3 group.

Identification of Gene Changes Induced by Dexamethasone in the Anterior Segment of the Human Eye Using Bioinformatics Analysis.

BACKGROUND Glucocorticoids (GCs)-induced glaucoma is a common adverse effect of prolonged GCs use. To better understand the effects of GCs on aqueous humor (AH) outflow, we analyzed the dataset GSE37474 using bioinformatics analysis to identify gene changes and pathways in the anterior segment of the human eye induced by dexamethasone (DEX). MATERIAL AND METHODS The GSE37474 dataset downloaded from the Gene Expression Omnibus (GEO) database was examined in this study. GEO2R was utilized to analyze data and identify differentially expressed genes (DEGs). Gene Ontology (GO) enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were constructed using the DAVID database followed by construction of a protein-protein interaction (PPI) network performed using Cytoscape software. Finally, modules and hub genes were screened out using MCODE and cytoHubba plugin, respectively. RESULTS A set of 252 DEGs were screened. Among the DEGs, 143 genes were upregulated and 109 were downregulated. GO analysis indicated that some of the DEGs participated in extracellular matrix (ECM) organization and cholesterol homeostasis. Additionally, KEGG pathways were predominantly enriched in tyrosine metabolism and ECM-receptor interaction. From the PPI network, 2 modules were identified, and 10 hub genes were screened out, including CCL2, FOS, IGF1, PTGS2, CCL5, EDN1, IL11, F3, PMCH, and BDKRB1. The 2 module genes primarily participate in the TNF signaling pathway, cytokine-cytokine receptor interaction, and the Jak-STAT signaling pathway. CONCLUSIONS The present study identified some significant DEGs, hub genes, pathways, and modules in the human anterior segment induced by DEX. These results demonstrate that DEX changes the expression of certain genes and pathways to resist aqueous humor outflow, which could be new targets for developing novel and more effective approaches of diagnosis and therapy for GCs-induced glaucoma.

Catechin Weakens Diabetic Retinopathy by Inhibiting the Expression of NF-κB Signaling Pathway-Mediated Inflammatory Factors.

OBJECTIVE: The aim of the present study was to explore the role of catechin on the expression of heat shock protein 27 (HSP27), nuclear factor-kappa beta (NF-κB) and inflammatory factors IL-1ß, IL-6 and TNF-α in streptozotocin (STZ)-induced diabetic retinopathy (DR) rats. METHODS: A total of 150 rats were selected and randomly assigned to five groups: control group, STZ group, and three groups with different concentrations of catechin (low, middle and high concentrations). After STZ induction, DR rats were treated with different concentrations of catechin (50 mg/kg/day, low catechin group; 100 mg/kg/ day, middle catechin group; 200 mg/kg/day, high catechin group) by intravitreal injection for eight weeks. Hematoxylin and eosin (H&E) staining was used to observe the pathological changes in retinal tissues. The mRNA and protein levels of HSP27 in the retina were determined by RT-PCR and western blotting. Furthermore, the expression of NF-κB p65 and p-NF-κB p65 were determined by western blotting, while the expression of IL-1ß, IL-6, and TNF-α were determined by ELISA. RESULTS: HSP27 levels increased in STZ-induced DR rats, and became further upregulated after catechin treatment. Furthermore, IL-1ß, IL-6, and TNF-α levels were upregulated in the retinas of STZ-induced DR rats, but these changes were partially inhibited after treatment with catechin. Moreover, the application of catechin inhibited the activation of NF-κB, which was upregulated in STZ-induced DR. A negative correlation was observed between the concentrations of catechin and the expression of inflammatory factors. CONCLUSION: Catechin can weaken DR induced by STZ by increasing HSP27 levels and decreasing the production of associated inflammatory factors. This could help to treat DR in clinic.

Protective effects of ciliary neurotrophic factor on the retinal ganglion cells by injure of hydrogen peroxide.

AIM: To explore the effect of ciliary neurotrophic factor (CNTF) on retinal ganglion cell (RGC)-5 induced by hydrogen peroxide (H2O2). METHODS: After cell adherence, RGC-5 culture medium was changed to contain different concentrations of H2O2 from 50 to 150 µmol/L at four time points (0.5, 1, 1.5 and 2h) to select the concentration and time point for H2O2 induced model. Two different ways of interventions for injured RGC-5 cells respectively were CNTF as an addition in the culture medium or recombinant lentiviral plasmid carrying CNTF gene transfecting bone mesenchymal stem cells (BMSCs) for co-culture with RGC-5. RESULTS: Compared to the control group, H2O2 led to RGC-5 death closely associated with concentrations and action time of H2O2 and we chose 125 µmol/L and 2h to establish the H2O2-induced model. While CNTF inhibited the loss of RGC-5 cells obviously with a dose-dependent survival rate. Nevertheless two administration routes had different survival rate yet higher rate in recombinant lentiviral plasmid group but there were no statistically significant differences. CONCLUSION: Both the two administration routes of CNTF have effects on RGC-5 cells induced by H2O2. If their own advantages were combined, there may be a better administration route.

Efficacy and Safety of 23-Gauge Pars Plana Vitrectomy/Silicone Oil Tamponade Combination for Treatment of Pediatric Post-Traumatic Endophthalmitis.

PURPOSE: To determine (i) the etiology, epidemiology, mechanism of injury, and risk factors associated with open globe injuries (OGIs) in children and (ii) visual outcomes of pediatric patients with post-traumatic endophthalmitis following 23-gauge pars plana vitrectomy (PPV) combined with silicone oil tamponade (SOT). METHODS: A total of 107 consecutive patients, <15 years of age, who had been diagnosed with post-traumatic endophthalmitis between September 2009 and October 2015, were included in this 6-year retrospective study. All patients had undergone a combined PPV and SOT procedure. We reviewed records and analyzed several parameters, including age, gender, wound anatomy, intraocular foreign body characteristics, best-corrected visual acuity (BCVA), and anatomic re-attachment of the vitreous. Visual acuity (VA) was evaluated by comparing the Ocular Trauma Scores (OTS) system with BCVA (as assessed by Fisher's exact test). RESULTS: Patients included 70 (65.42%) boys and 37 (34.58%) girls (mean, 7.84 ± 2.31 years). Mean follow-up time was 13.31 ± 3.15 months. Zone-1 injuries accounted for 15 of 107 (14.02%) cases, while Zones-2 and -3 accounted for 69 of 107 (64.49%), and 23 of 107 (21.50%) cases, respectively. Lens trauma was noted in 53 of 107 (49.53%) eyes. Our analysis showed that the 6-month BCVA, as assessed by OTS, differed significantly between groups OTS-1 (p = 0.001) and OTS-2 (p = 0.012). No significant difference was observed in group OST-3 (p = 1.000). Total retinal attachment was achieved in 99 of 107 eyes (92.52%). CONCLUSIONS: Following combined PPV/SOT for post-traumatic endophthalmitis, VAs were not only favorable, but also often better than those predicted by OTS. Increased awareness of the very serious nature of endophthalmitis is expected to help in the development of a comprehensive strategy designed to educate both parents and children, and to minimize the number of preventable pediatric OGIs.

In vitro induction and differentiation of umbilical cord mesenchymal stem cells into neuron-like cells by all-trans retinoic acid.

AIM: To determine the optimal concentration for inducing the differentiation of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) into neuron-like cells, although it is understood that all-trans retinoic acid (ATRA) regulates cell proliferation in the nervous system by modulating the balance between mitosis and apoptosis. METHODS: The abilities of ATRA to promote apoptosis as well as neural differentiation were assessed in cultured hUC-MSCs by morphological observation, MTT assay, annexin V-FITC/PI flow cytometry and immunocytochemistry. RESULTS: The data showed that low concentrations of ATRA (0.5 µmol, 0.25 µmol) had no effect on the number of cells. However, treatment with 1.0 µmol or 2.0 µmol ATRA induced a 24.16% and 52.67% reduction in cell number, respectively, compared with vehicle-treated cultures. Further, 4.0 µmol ATRA had a potent effect on cell number, with almost no adherent cells recovered after 24h. We further showed that 0.5 µmol ATRA caused these cells to express characteristic markers of neuronal progenitor cells. CONCLUSION: Taken together, we conclude that ATRA has a dose-dependent influence on the neural differentiation and apoptosis of hUC-MSCs. These findings have implications on the use of ATRA-differentiated hUC-MSCs for the study of neural degeneration diseases.

Management of delayed suprachoriodal haemorrhage after intraocular surgery and trauma.

BACKGROUND: [corrected] To indentify surgical risk factors for delayed suprachoroidal haemorrhage (DSCH) and to report the outcomes of an effective intervention in a consecutive of patients. METHODS: The clinical data of ten patients diagnosed with DSCH in our hospital between July 2007 and December 2012 were extracted from hospital records and analyzed, including ophthalmologic examination, ophthalmologic ultrasonography, surgical procedures, and outcome measures including visual acuity and intraocular pressure. RESULTS: Ten eyes of ten patients including six men and four women with mean age of 56.6 ± 17.67 years, with DSCH, were enrolled. After diagnosis, drainage or/and pars plana vitrectomy were performed for eight patients; another two received conservative treatment. All the patients were followed up for 15.2 ± 4.3 months. Intraocular pressure decreased significantly (p < 0.001); the mean final visual acuity improved significantly after intervention (p < 0.001). CONCLUSIONS: We emphasized other great risk factors such as intraoperative mitomycin-C use, systemic anticoagulation or thrombolysis, and chronic kidney disease. It seems that earlier surgical intervention after the diagnosis of DSCH will be beneficial to patients by improving their final visual acuity.

c-Jun N-terminal kinase is involved in the regulation of proliferation and apoptosis by integrin-linked kinase in human retinoblastoma cells.

PURPOSE: To determine the presence of integrin-linked kinase (ILK) in tissue samples of retinoblastoma patients, and to explore the function of ILK in human Y79 retinoblastoma cells. METHODS: The expression of ILK was studied in samples of retinoblastoma patients by immunohistochemistry. In vitro, specific small interfering RNA (siRNA) targeting ILK was transfected into Y79 retinoblastoma cells using liposome. Silencing of ILK expression was measured by reverse transcription-polymerase chain reaction (RT-PCR), real-time PCR and Western blotting assays. Then the regulation of cell proliferation and apoptosis was assessed by Cell Counting Kit-8(CCK-8), Annexin V-FITC/ propidium iodide (PI) immunofluorescence, and flow cytometry assays. Furthermore, the involvement of c-Jun N-terminal kinase signal pathway was tested by JNK signal transduction inhibitor assay. RESULTS: Positive staining for ILK was detected in 15 of the 17 retinoblastoma tissue samples. Specific siRNA targeting ILK significantly silenced ILK expression in Y79 retinoblastoma cells, as confirmed by RT-PCR, real-time PCR and Western blotting assays (P < 0.01). This was accompanied by decreased cell proliferation (P < 0.05) and enhanced apoptosis (P < 0.01). The phosphorylation status of JNK and c-Jun was constitutively activated by ILK siRNA (P < 0.01), and JNK inhibitor simultaneously reversed the effects on cell proliferation and apoptosis induced by ILK siRNA. CONCLUSION: Our results demonstrated that ILK promoted proliferation and suppressed apoptosis via repressing phosphorylations of the JNK signal pathway in human retinoblastoma cells. This might provide a potential therapeutic target in the treatment of this deadly disease.

[anastomosis lacrimal sac conjunctival sac in severe laceration of lacrimal canaliculus].

PURPOSE: To investigate the clinical effect of anastomosis lacrimal sac conjunctival sac in the treatment of severe laceration of lacrimal canaliculus. METHODS: A total of 19 cases (19 eyes) with laceration of lacrimal canaliculus underwent anastomosis lacrimal sac conjunctival sac.All the patients were followed up for 3 to 24 months postoperatively. RESULTS: Among all the 19 patients (19 eyes), 14 cases were cured,3 cases wre markedly improved and 2 cases had no effect,and the effect rate was 89.47%. CONCLUSION: Anastomosis lacrimal sac conjunctival sac is an effective surgical technique in the management of severe laceration of lacrimal canaliculus.

[Differentiation and apoptosis effects of all-trans retinoic acid on inducing umbilical cord mesenchymal stem cells into neuron-like cells].

OBJECTIVE: To evaluate the role of different concentration of all-trans retinoic acid (ATRA) on the morphology, proliferation and apoptosis in inducing umbilical cord mesenchymal stem cells (MSC) into neuron-like cells in vitro, and screen the optimal concentration of ATRA. METHODS: It was an experimental study. The third passage of MSC was placed in 24-well cell culture plates at a density of 1 × 10(4)/well. After the adherent of cells, the medium was changed to DMEM/F-12 containing different concentration of ATRA (0.25 µmol/L, 0.5 µmol/L, 1.0 µmol/L, 2.0 µmol/L, 4.0 µmol/L) for 24 h respectively. The cells cultured without ATRA were taken as the control group. After another 24 h, the morphologic changes of induced cells were observed by inverted microscope and cell proliferation, apoptosis of ATRA was analyzed using the MTT colorimetric assay. We take another control group and ATRA groups to detect the apoptotic and positive stained percentage of induced cells by Annexin V-FITC/PI combining flow cytometry. The optimal concentration of ATRA was determined by all the above-mentioned index. According to the nature of the material, analysis of variance (ANOVA) was employed for absorption value and apoptosis rate in different concentration of ATRA for 24 h, t test for further comparison between two groups. T-test were also used between the positive expression of induced neuron-like cells and the control group. RESULTS: Compared to the control group, ATRA at the concentration of 0.25 µmol/L did not inhibit the proliferation of umbilical cord MSC obviously (t = 0.72, 1.32, P > 0.05). Part of MSC were floating instantly at the moment of adding ATRA of 4.0 µmol/L and no adherent cells were observed after 24 h' culture. Exposed to ATRA at the concentration of ≥ 1.0 µmol/L for 24 h, the proliferation of MSC were significantly inhibited, showing a dose-dependent manner (t = 8.8, 18.9, 22.1; P < 0.01). 0.5 µmol/L of ATRA did not affect the proliferation of cells and its morphology remained normal; 1.0 µmol/L of ATRA affected very few cells; but 2.0 µmol/L of ATRA cultured for 24 h inhibited the proliferation of cells obviously than 1 h, and the cells increased in size and became flattened. Flow cytometry showed that the rate of apoptosis between the control group and ≥ 1.0 µmol/L groups were significantly different (t = 9.88, 19.95, 31.61; P < 0.01). CONCLUSION: In the process of inducing umbilical cord MSC into neuron-like cells, 0.5 µmol/L ATRA was the optical concentration. ≥ 1.0 µmol/L ATRA can inhibit the cell proliferation, increase the apoptosis of cells significantly and caused obvious damages.

Epidermal growth factor promotes the differentiation of stem cells derived from human umbilical cord blood into neuron-like cells via taurine induction in vitro.

Results of recent investigations have demonstrated the plasticity of mesenchymal stem cells (MSC) can differentiate into neural lineages. In this study, we explored the experimental condition of differentiation into neuron-like cells or rhodopsin (RHOS)-positive cells induced by epidermal growth factor (EGF) and taurine in vitro and to investigate their biological characteristics. MSC were obtained from umbilical cord blood (UCB) of term deliveries. Cultured cells were treated with Dulbecco's modified Eagle's medium/F12 (pH 7.0-7.2) supplemented with 30 ng/ml EGF. After the third cell passage, the cells were trysinized and analyzed with a flow cytometer using the following monocloned antibodies: CD90, CD29, CD34, CD44, and CD45. Taking another MSC of the third passage, its basal medium was replaced with alpha minimum essential medium supplemented with taurine (50 micromol/L). Cells were cultured for an additional 8-10 d, fixed, and then immunocytochemically analyzed. Primary antibodies included the following: neuron-specific enolase (NSE), RHOS, and nestin. In our study, we isolated a cell population derived from UCB, which possesses morphological characteristics similar to those of MSC isolated from bone marrow. In the cytometric analysis, MSC did not present labeling for the hematopoietic line (CD34 and CD45) and were positive for CD29, CD44, and CD90. After induction by taurine, 80.5 +/- 16.2% of the cell population expressed NSE, 36.8 +/- 9.6% expressed RHOS, and 29.6 +/- 9.3% expressed Nestin, while only 7.9 +/- 3.5% expressed NSE in the control group. This study demonstrates that partial MSC induced by taurine and EGF can differentiate into neuron-like cells or RHOS-positive cells in vitro, which may provide a promising therapeutic strategy for the treatment of some forms of retinal degeneration.

Suprachoroidal hemorrhage during pars plana vitrectomy in traumatized eyes.

BACKGROUND: Suprachoroidal hemorrhage (SCH) is a rare but dangerous complication of intraocular surgery. There are some risk factors for this devastating complication during pars plana vitrectomy. In this case, we will report the intraoperative occurrence of SCH during pars plana vitrectomy in traumatized eyes. METHODS: Retrospective analysis of SCH during pars plana vitrectomy in five eyes with the history of blunt (n = 1) or penetrating (n = 4) trauma was made. Baseline systemic and ocular characteristics, surgical procedures, time point of SCH, management of SCH, and final visual outcomes were measured. RESULTS: One eye with associated myopia developed SCH during the time of producing vitreous posterior detachment under ocular hypotony. In other two eyes, SCH developed under ocular hypotony during fluid-gas exchange. The remaining two eyes got SCH when the depression of the area of pars plana occurred. Sclerotomy closure was performed immediately once SCH occurred. Vitrectomy and posterior sclerotomy were then performed between 8 and 12 days later. After a median follow-up of 12 months (range: 3-20 months), final visual acuity was above 20/400 in four eyes, no light perception in one eye, the best visual acuity was 20/60. CONCLUSIONS: Ocular trauma is one of the vital risk factors for the development of intraoperative SCH during pars plana vitrectomy. It is important to control effectively the intraocular inflammation preoperatively and avoid abrupt ocular hypotony and pressure on the area of pars plana intraoperatively to the limit.