Dendrobium nobile Lindley and its bibenzyl component moscatilin are able to protect retinal cells from ischemia/hypoxia by dowregulating placental growth factor and upregulating Norrie disease protein.

BACKGROUND: Presumably, progression of developmental retinal vascular disorders is mainly driven by persistent ischemia/hypoxia. An investigation into vision-threatening retinal ischemia remains important. Our aim was to evaluate, in relation to retinal ischemia, protective effects and mechanisms of Dendrobium nobile Lindley (DNL) and its bibenzyl component moscatilin. The therapeutic mechanisms included evaluations of levels of placental growth factor (PLGF) and Norrie disease protein (NDP). METHODS: An oxygen glucose deprivation (OGD) model involved cells cultured in DMEM containing 1% O2, 94% N2 and 0 g/L glucose. High intraocular pressure (HIOP)-induced retinal ischemia was created by increasing IOP to 120 mmHg for 60 min in Wistar rats. The methods included electroretinogram (ERG), histopathology, MTT assay and biochemistry. RESULTS: When compared with cells cultured in DMEM containing DMSO (DMSO+DMEM), cells subjected to OGD and pre-administrated with DMSO (DMSO+OGD) showed a significant reduction in the cell viability and NDP expression. Moreover, cells that received OGD and 1 h pre-administration of 0.1 µM moscatilin (Pre-OGD Mos 0.1 µM) showed a significant counteraction of the OGD-induced decreased cell viability. Furthermore, compared with the DMSO+OGD group (44.54 ± 3.15%), there was significant elevated NDP levels in the Pre-OGD Mos 0.1 µM group (108.38 ± 29.33%). Additionally, there were significant ischemic alterations, namely reduced ERG b-wave, less numerous retinal ganglion cells, decreased inner retinal thickness, and reduced/enhanced amacrine's ChAT/Müller's GFAP or vimentin immunolabelings. Moreover, there were significantly increased protein levels of HIF-1α, VEGF, PKM2, RBP2 and, particularly, PLGF (pg/ml; Sham vs. Vehicle: 15.11 ± 1.58 vs. 39.53 ± 5.25). These ischemic effects were significantly altered when 1.0 g/Kg/day DNL (DNL1.0 + I/R or I/R+ DNL1.0) was applied before and/or after ischemia, but not vehicle (Vehicle+I/R). Of novelty and significance, the DNL1.0 action mechanism appears to be similar to that of the anti-PLGF Eylea [PLGF (pg/ml); DNL1.0 vs. Eylea+I/R: 19.93 ± 2.24 vs. 6.44 ± 0.60]. CONCLUSIONS: DNL and moscatilin are able to protect against retinal ischemic/hypoxic changes respectively by downregulating PLGF and upregulating NDP. Progression of developmental retinal vascular disorders such as Norrie disease due to persistent ischemia/hypoxia might be thus prevented.

Aortic valve surgery: how reliable are health information websites?

BACKGROUND: Aortic valve replacement is one of the most common cardiac operations currently performed. Patients increasingly use the internet for information about their diagnosis and it would therefore be important to know how reliable this is. AIM: To determine the reliability of internet information on aortic valve replacement surgery. DESIGN & SETTING: This was a web-based project scoring sites that might be accessed by a patient. METHOD: The first 50 websites found on each of the four most popular search engines in the UK were viewed, as well as the first 50 videos found on the most popular video-host website. Eligible websites were assessed according to seven positive criteria and three negative criteria, giving a possible range of scores from -6 to 14. RESULTS: There were 79 sites and the median score was 5 (range -1 to 14). There were statistically significant differences between organisation/educational sites with score 7 (2 to 14), hospital sites with score 2 (-1 to 10), commercial sites with score 2.5 (0 to 9) and videos with score 5 (2 to 11). The highest scores went to three NHS sites (score 13 or 14), .gov sites (median score 8.5) and Health On the Net Foundation (HON) accredited sites (median score 7). CONCLUSION: Information on the internet about aortic valve replacement is variable but NHS sites provide the most reliable information.