Comparison of Collagen Cross-Linking and Amniotic Membrane Transplantation in an Experimental Alkali Burn Rabbit Model.

PURPOSE: To compare the effects of collagen cross-linking (CXL) and amniotic membrane transplantation (AMT) on acute corneal alkali burns. METHODS: After establishment of an alkali burn model, 32 rabbits were divided into 4 groups: control group, AMT group, CXL group, and AMT + CXL (combined) group. Clinical parameters, including epithelial wound, opacity, ulceration, and neovascularization, were evaluated on postinjury days 1, 7, 14, and 18. Histological parameters were examined in hematoxylin/eosin (H&E) and Masson trichrome-stained corneal sections. Immunohistochemical analyses, including a terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling assay and cluster of differentiation 68 (CD68) labeling, were performed to determine the apoptotic index and macrophage activation. RESULTS: On postinjury day 18, the epithelial wound of AMT {4.08% [interquartile range (IQR), 0.68%-5.22%]}, CXL [1.84% (IQR, 0.01%-3.89%)], and combined [3.44% (IQR, 0.01%-4.36%)] groups were significantly lower than the control [15.23% (IQR, 9.86%-23.06%)] group (P = 0.003). No significant difference was detected between the groups in terms of opacity (P = 0.303). Neovascularization was the least severe in the CXL group [16.18% (IQR, 8.39%-21.28%)] and the most severe in the AMT [34.47% (IQR, 17.71%-62.77%)] and combined [35.12% (IQR, 31.96%-59.98%)] groups on day 18 (P = 0.033). Significant increases in the apoptotic index and CD68 labeling were detected in the CXL and combined groups compared with those in the control group (P = 0.047 and P = 0.001, respectively). CONCLUSIONS: CXL treatment is an effective adjuvant treatment for promoting reepithelialization, reducing inflammation and neovascularization, and preventing ulceration in acute alkali burns. Providing AMT after suppressing inflammation may be a more effective treatment.

Comparison of hyperbaric oxygen versus iloprost treatment in an experimental rat central retinal artery occlusion model.

PURPOSE: Central retinal artery occlusion (CRAO) is one of the serious ophthalmological emergencies with poor visual prognosis. Iloprost is a stable prostacyclin analogue and has prominent anti-edema, anti-inflammatory, vasodilatory, and antiagregant effects. The main objective of this work was to investigate iloprost as an alternative agent versus hyperbaric oxygen (HBO) in the treatment of CRAO. METHODS: Twenty-eight healthy Wistar albino male rats were randomly assigned into control (n = 7, sham operation), HBO (n = 7), iloprost (n = 7), and sham groups (n = 7). CRAO model was created through optic nerve exploration and ligation. Full-thickness retina (FTR), outer nuclear layer (ONL), inner nuclear layer (INL) and ganglion cell layer (GCL) thickness were measured on Hematoxylin/Eosin (H&E) stained retinal sections and immunohistochemical analysis including terminal deoxynucleotidyl transferase-mediated biotindeoxyuridine triphosphate nick-end labeling (TUNEL) assay was performed to determine the apoptotic index (AI). RESULTS: AI values of HBO (0.204 ± 0.067) and iloprost (0.197 ± 0.052) groups were significantly lower than sham (0.487 ± 0.046) group (p < 0.001). Any significant difference was found between the HBO and iloprost groups in terms of AI (p = 0.514). A statistically significant increase in thickness of FTR, ONL, INL and GCL was detected in HBO, iloprost and sham groups compared to the control group (p = 0.002). FTR, ONL, INL and GCL thickness were significantly thinner in HBO and iloprost groups than in the sham group (p = 0.002). A significant lesser increase was observed in all the retinal layers thickness in iloprost group versus HBO group (p = 0.002) except for INL (p = 0.665). CONCLUSIONS: The study results demonstrated anti-edema, neuroprotective, and anti-apoptotic effects of iloprost quantitatively; thus, iloprost may be a beneficial alternative agent in the treatment of CRAO.

Protective effect of IGF-1 on experimental liver cirrhosis-induced common bile duct ligation.

BACKGROUND/AIMS: The causes of malnutrition in liver cirrhosis are multifactorial. Levels of IGF-1 (insulin like growth factor-1) that is a crucial regulator of intermediary metabolism decreases. The aim of this study was to analyze the effect of IGF-1 supplementation during liver cirrhosis induced by common bile duct ligation. METHODOLOGY: Rats were divided into five different groups: One sham and four experimental groups. Rats in three of four groups were treated with 2 micrograms/day IGF-1 with a different time of experiment in each group. Blood biochemical parameters, tissue malondialdehyde, glutathione levels and the activity of tissue antioxidant enzymes and conventional and immunohistochemical analysis of liver samples were studied for each group. RESULTS: Serum albumin, total protein, fibrinogen levels decreased and prothrombin time was prolonged in the bile duct ligated and transected experimental group but not in the IGF-I treated rats compared with the rats in sham group. Liver malondialdehyde levels significantly increased in control group but not in IGF-1 treated groups. The activities of antioxidant enzymes were decreased compared with the other groups. Histopathology findings of liver biopsy demonstrated intense degree fibrosis and overexpression of fibroblast growth factor and desmin in the control group but a lesser degree of those in the IGF-1 treated groups. CONCLUSIONS: IGF-1 treatment improves liver function and decreases oxidative liver damage and histopathological findings. Further studies are required to delineate the mechanisms of protective effects of IGF-1.