Want to make a few notes on flow-mediated dilation and this thread seemed as good a place as any! 1. The Youtube video where Mella talks about flow-mediated dilation is now online here. (This is the November talk where he gives the bad news on Rituximab.) It is a good talk with english subtitles. Gives a sense of the work they are still doing. The graphics are covered up in the talk. But you can find one of them if you want to see the data. 2. I found this study gave me a good sense for what flow mediated dilation problems are. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2014404/ It suggests high doses of L-arginine and says even vitamin C has been shown to help a little. -- 3. I have grown increasingly interested in the theory me/cfs is partly endothelial and there is mounting evidence. Here's something I wrote a couple of years ago: My personal experience is that two seemingly distinct things trigger fatigue attacks. Alcohol and Exercise. Recently I realised that what links them is vascular dilation. This presentation by Professor Chris Callaghan was pretty important in shaping my thinking too. http://emerge.org.au/mr-chris-ocallaghan-disorders-blood-pressure-connective-tissue-elasticity/ I now wear compression pants all the time, eat a lot more salt, drink a lot of water and I have stopped worrying about my caffeine intake. I now suspect the reason I'm so mad for coffee is its vasoconstricting effects! But how to integrate this with the perception that CFS is an immune disorder? Perhaps an autoimmune response is attacking the cells responsible for vasoconstriction and dilation (the endothelium ?). If the immune system is attacking other kinds of epithelial cells too this could explain a wider set of symptoms. Prof Callaghan believes that CFS is correlated with joint hypermobility (where connective tissue is degraded by autoimmune) and that CFS and hypermobility could be different manifestations of a broader autoimmune response. -- 4. I am probably now less obsessed with the idea the problems with the endothelium need to be about antibodies. Could be anything, but a failure to ship blood and oxygen round the body can explain almost all our symptoms from cog fog to lactic acid, as well as providing an explanation for exercise intolerance and PEM.