Originally posted by Dr Deco
There does not exist any specificity of the immune system for dissolved gas. Whatever reactions occur, these are directed at the gas phase. Some have even claimed specificity. I once heard a presentation by Dr. Ward at an Undersea and Hyperbaric Medical Society meeting in which he found a difference in complement activation between bubbles of helium versus bubbles on nitrogen. I asked him then if that implied that had indeed found a chemical test, at room temperature, for an inert gas. He indicated that he thought so - - - I expressed doubt.
For those of you that don't know (I can't remember if I ever said) I reached the dizzy heights (or doubious station) in life as a vaccine / immunology bod via a degree in chemistry, and then a PhD in Pharmacy (vaccine delivery mechanisms) so........
As a chemist -- This test for a noble gas is bollocks!
Simple chemistry should immediately tell us that helium, which has a full, complete, and nice and happy set of molecular orbitals has never been made to react with ANYTHING at any temperature anywhere near RT.
Similarly, N2, which although is not a noble gas, is a very nice and inert gas. There are very few (if any) reactions of gaseous nitrogen. Without a textbook here to look things up in, I don't know of any, and I suspect that gaseous N2 is about as inert as helium.
If he has a simple chemical test for these two, then it isn't just time for a paper or two in nature, this is nobel prize type work (certainly one in chemistry, and probably a second for physics) as it is overturning the vast majority of theoretical chemistry research for the last 100 years or so (plus invalidating the whole of quantum mechanics, all chemical bonding theory etc.....)
As an immunologist............ someone posted a link to an article about DCS and the immune system, (I printed it and didn't keep the link). My opinion was that this article was pretty much wishfull thinking with minimum scientific evidence to support it.
The article described most of the key areas of the immune system, and tried to apply them to DCS. Unfortunately, the authors also failed to put everything into perspective as to where everything fitted into the grand scale of things. certain mechanisms they quoted, for example protein denaturation, don't just occur in DCS, but occur all the time, and there are specific (and highly successfull) mechanisms for dealing with them.
They also considered the raising of antibodies to N2, and other disolved (and bubbles of) gasses (the humoral response). Unfortunately (as Dr Deco points out) disolved gasses can't induce an immune response. They fail to mention in the article processes such as antigen presentation which are necessary to induce a humoral response. Basically antigen presentation only works for proteins, although there are other (not humoral, but innate) mechanisms that can induce an immune response. But, if you think that even at ambient pressure we are saturated with dissolved N2 (don't forget saturation level is dependent upon the partial pressure of the gas we breath). As this is the case, if it was possible to raise antibodies to N2 we would have been doing so ever since birth, and would have some pretty nasty reactions every time we breath. Something that is evolutionarily negative!
What I concluded from the article was that bubbles caused minor MECHANICAL damage, and the body mounted a NORMAL immune response to minor damage - in essense the same reaction as to a minor insult such as a cut.
I wasn't impressed by the article, neither am I impressed by the idea that someone can readily distinguish between bubbles of different inert gasses, unless they have spent a
lot of money attaching their experiment to something like a MALDI-TOF-MS. In the past identifying inert gasses has been the work of nobel prizes, and it is still not the easiest of things to do.
.02 as always
Jon T
