MATERIAL AND METHODS: RIN-m5F cells were cultured in normal (5 mM) and high (25 mM) glucose to mimic diabetic conditions, followed by treatment with 5 µM, 10 µM and 20 µM of isoproterenol and isoproterenol + propranolol for 6, 12 and 24 h. Western blotting and reverse transcription analysis were performed to examine the expression of RAF-1 and PDX-1. Annexin-V-FITC and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays were used to investigate apoptosis. ELISA was used to measure insulin levels. Reverse transcription polymerase chain reaction was conducted to investigate the expression of genes.
RESULTS: Stimulation of β-adrenergic receptors with isoproterenol significantly induced RAF-1 and PDX-1 genes in a concentration-dependent and time-independent manner. Changes were significant both at protein and mRNA levels. Up-regulation of RAF-1 and PDX-1 was accompanied by improved insulin levels and reduced apoptosis. Concentrations of 10 µM and 20 µM for 12 and 24 h were more effective in achieving significant differences in the experimental and control groups. Propranolol reversed the effect of isoproterenol mostly at maximum concentrations and time periods.
CONCLUSIONS: A positive effect of a β-adrenergic agonist on RAF-1 and PDX-1, reduction in β-cell apoptosis and improved insulin contents can help to understand the pathogenesis of diabetes and to develop novel approaches for the β-cell dysfunction in diabetes.
METHODS: Human Müller cells were cultured in low and high glucose conditions. Cells were treated with xamoterol (selective agonist for β1-AR), salmeterol (selective agonist for β2-AR), isoproterenol (β-ARs agonist) and propranolol (β-ARs antagonist), at 20 µM concentration for 24 h. Western Blotting assay was performed for the gene expression analysis. DNA damage was evaluated by TUNEL assay. DCFH-DA assay was used to check the level of reactive oxygen species (ROS). Cytochrome C release was measured by ELISA.
RESULTS: Xamoterol, salmeterol and isoproterenol showed no effect on Caspase-8 but it reduced the apoptosis and increased the expression of BDNF in Müller cells. A significant change in the expression of caspase-3 was observed in cells treated with xamoterol and salmeterol as compared to isoproterenol. Xamoterol, salmeterol and isoproterenol significantly decreased the reactive oxygen species (ROS) when treated for 24 hours. Glucose-induced cytochrome c release was disrupted in Müller cells.
CONCLUSION: β-ARs, stimulated by agonist play a protective role in hyperglycemic Müller cells, with the suppression of glucose-induced caspase-3 and cytochrome c release. B-Ars may directly mediate the gene expression of BDNF.
METHODS: This was a retrospective cohort study of all patients treated between January 2005 and December 2010.
RESULTS: We included 163 patients with an age range of 6-59 years (median = 19). The median follow-up was 47 months (range 36-84). The overall survival in patients who completed chemotherapy and surgery (n = 117) was 72% at 2 years and 44% at 5 years. Histologically, 99 (85%) had osteoblastic, 6 (5%) had chondroblastic and 3 (2.5%) had telangiectatic osteosarcoma. Limb salvage surgery was performed in 80 (49%) and 41 (25%) underwent amputation. However, 46 patients (28%) underwent no surgical intervention and incomplete chemotherapy. In total, 38/79 patients had a good chemotherapy response. There was a significantly better survival rate for limb salvage versus amputation. Independent prognostic factors for survival are compliance to treatment and presence of lung metastasis.
CONCLUSION: The overall survival of osteosarcoma patients was influenced by the presence of pulmonary metastases and compliance to treatment. Histological subtype, different chemotherapy regimens and histological necrosis after chemotherapy did not significantly influence survival. The patients who did not complete treatment had significantly poorer survival.