Objective To observe the effect of panretinal photocoagulation (PRP) on the expression of cyclooxygenase-2 (COX-2),vascular endothelial cell growth factor (VEGF) in epiretinal membrane of proliferative diabetic retinopathy (PDR).Methods A total of 35 patients (35 eyes) with PDR and underwent plana vitrectomy were enrolled in this study.The patients were divided into non-PRP group (19 patients,19 eyes) and PRP group (16 patients,16 eyes) depends on if they had received PRP before surgery.The epiretinal membranes stripped during operation were collected for pathological examination.The histopathological features was observed by haematoxylin and eosin stain.The expression of CD34,COX-2 and VEGF,and microvessel density (MVD) were measured by immunohistochemistry method.Results Many new dispersed capillary blood vessels were found in the thick epiretinal membranes of nonPRP group,while scattered small blood vessels were found in the relatively thin epiretinal membranes of PRP group.MVD value was (7.42± 1.39) in the non-PRP group and (4.56± 1.22) in the PRP group,which was lower than the non-PRP group (t=6.41,P＜0.01).The expression of CD34,COX-2 and VEGF in the tissues of epiretinal membrane in PRP group were obviously lower than the non-PRP group (t=6.147,5.944,7.445;P＜0.01).Conclusion PRP can effectively inhibit the expression of COX-2 and VEGF in epiretinal membrane of PRP patients.

Background and purpose: Pancreatic intraepithelial neoplasia (PanIN) is thought to be a precursor lesion of infiltrating pancreatic ductal adenocarcinoma. The mutation of the phenotypic impact of K-ras G12D alone, silencing of p53 and p16 could promote this process. The role of Smad4 in this progression was poorly understood. In the present study, we investigated the role of Smad4 in the development of pancreatic tumor, based on PanIN cell line from mice with K-ras G12D mutation in order to investigate the effect of Smad4 silencing on PanIN cells in the development and malignant transformation in nude mice. Methods: Smad4 knock-down PanIN cells (PanIN-S) were established by stable transfeetion with lentiviral-mediated Smad4 RNA interference (RNAi). In xenograft model experiments, BALB/c nude mice were randomly divided into 2 groups (5 mice per group) implanted with PanIN or PanlN-S cells subcutaneously. Two weeks after tumor cells inoculation, tumor volume and weight were estimated. PCNA staining was used to evaluate cell proliferation and CD31 polyclonal antibody was used to assess micro-vessel density (MVD) in tumors. Results: Effect of siRNA of Smad4 gene in PanlN cells was confirmed by RT-PCR and Western blot. Compared with PanlN groups, there was a dramatic increase in tumor volume and weight in PanIN-S groups (P<0.05). Furthermore, immunohistochemical analysis of the harvested tumors suggested that Smad4 silencing was associated with 'increased tumor cell proliferation (PCNA reactivity) and angiogenesis (micro-vessel density, MVD). The percentage of PCNA-positive cells in the PanlN-S groups were significantly increased than PanIN groups (P<0.05). CD31 staining revealed a significant increase in the PanlN-S groups compared to the PanlN groups (P<0.05). Conclusion: Silencing of Smad4 in PanlN cells with endogenous expression of K-ras G12D, enhanced progression to invasive adenocarcinomas. Cell proliferation and vascularization may be its important mechanisms.

Objective To investigate the nature of the suprachoroidal fluid by detecting the concentration of total protein (TP), lactate dehydrogenase (LDH), albumin (ALB), total cholesterol (CHOL), total bilirubin (TBIL) in suprachoroidal liquid of patients who have rhegmatogenous retinal detachment with choroid detachment (RRDCD). Methods Eighteen RRDCD patients (18 eyes) who underwent vitrectomy were enrolled in this study. There were 10 males (10 eyes) and 8 females (8 eyes), 8 right eyes and 10 left eyes. There were 8 patients with age of ≤55 years, 10 patients with age of >55 years. There were 7 patients with duration of≤30 days, 11 patients with duration of >30 days. There were 7 eyes with diopters of ≥-6.0 D, 11 eyes with diopters of <-6.0 D. There were 11 eyes with class C proliferative vitreoretinopathy (PVR), 7 eyes with class D PVR. Suprachoroidal fluid samples were collected from all the patients, and took preoperative serum samples as RRDCD group. Ten serum samples of normal people were set as control group. The concentration of TP, LDH, ALB, CHOL, TBIL in all the subjects were measured. The properties of the suprachoroidal fluid were identified by Light standard and concentration standard of ALB, CHOL, TBIL. Results There was no difference on the concentration of TP, LDH, ALB, CHOL, TBIL from suprachoroidal fluid samples in the patients with different age, sex, eyes, diopter, PVR grade (P>0.05). There was no difference on the concentration of TP, LDH, ALB, CHOL, TBIL from preoperative serum samples in the patients between RRDCD group and control group (P>0.05). There was no difference on the concentration of ALB and CHOL from suprachoroidal fluid samples and preoperative serum samples in the RRDCD patients (P>0.05), but there were significant differences on the concentration of TP, LDH, TBIL (P<0.05). According to the Light standard, there were 17 cases of exudates and 1 case of transudate. According to the concentration standard of ALB, CHOL and TBIL, there were 14, 18, and 16 cases of exudates, and 4, 0, and 2 cases of transudate, respectively. There was no difference on the identification result of Light standard and concentration standard of ALB, CHOL, TBIL (χ2=2.090, 1.029, 0.364;P>0.05). Conclusion The suprachoroidal fluid of RRDCD patients composed of TP, LDH, CHOL and TBIL. The suprachoroidal fluid is more likely to be exudate.