Let's talk about the H1N1 virus. I know you haven't heard enough about it on the TV and the radio and the internet and the newspaper and Twitter and Facebook. (Did I leave anybody out?)
First, go read what I did at Boing-Boing about cytokines and a cytokine storm.
Then read what Older Son has to say on the subject.
Huh, she didn't actually say what a cytokine storm is. It's not that hard to explain. Cytokines are the chemical messengers of the immune system, the way that different kinds of white blood cellsB cells and T cells talk to each other over distances. The ones responsible for a cytokine storm are inflammatory cytokines, which, among other effects, make all your tiny little blood vessels
more permeable to everything. They open little windows in their
walls. The point of this is to let cells of the immune system leave
the blood and go into a particular tissue that has nasty microbes in
it, like for example because you fell down and cut your arm on a sharp
rock. The little blood vessels open to let the white blood cells into
the tissue, but the red blood cells
and the fluid of your blood (plasma) go along for the ride once holes
open up in the walls of the little vessels. This is why you get
redness and swelling, because there's blood loose in the tissue, and
it's fine and helpful if it just happens in one spot. But for somewhat
complicated technical reasons, some diseases are able to cause you to
secrete such a large quantity of inflammatory cytokines into your
bloodstream that all of your little blood vessels open windows in themselves. When you lose blood from every little blood vessel,
then you just don't have enough blood, it's as if you'd slit your
wrists or jugular and let all your blood run out. So you go into
shock, which just means that your blood can't adequately supply stuff
to your tissues systemically (as opposed to just in a particular spot,
locally, which is called ischemia). This includes your brain, and when
your brain goes without get glucose and oxygen for a few minutes you
die.
Also, that lady didn't make the point that for any bug, including
this one, your probability of developing the infection absolutely
depends on how much of it gets into your body. It also depends on how
good your immune system is and how few of this organism are able to
cause disease in a healthy person (the infectious dose). But you can't
control either of those, and if they're constant the thing you can have
some control over is how many of the things get into your system.
That's why even a mask that doesn't stop all of the virus can be a good
idea.
Andrew
The other thing The Boy told us on the phone last night was that the difference betweeen cytokines and hormones was that the former were discovered/studied by microbiologists (I think) and the latter were discovered/studied by endocrinologists. They do essentially the same thing, enable communication between cells. That is of course a cynical oversimplification of the sort that always appeals to me, so you may take it with however much salt you deem appropriate.
And now you know lots about virii and cytokines and such.
