Saturday, January 15, 2011

cytokines and fire-fighters

Yes, it was sunny. Ten degrees F (12 degrees C) but warm enough. I thought of what Pierre said. Pierre is from West Africa: Benin and Togo. He said, "Anyone can live in Maine. They just have to have the right clothes." I picture him fairly bundled up as he said this.

I was wearing 3 shirts, snowpants and jacket, wool and silk hijab scarf, boots, hat, thick gloves, and snowshoes. All quiet and no one else on the mountain. The snow was soft and dry.

So I snowshoed up, Fluff following happily in the windblown areas, more reluctantly where the snow was deep. I could see sled tracks and beer cans at the bottom; the students are back from Christmas break. We got above the tree line; the granite top was bare.

Sirens rang around the base of the mountain. I saw fire trucks. I started thinking about cytokines.

See, I taught inflammation and the immune response this week. A 5-hour lecture. Cytokines are messengers of the immune cascade. They're like fire alarms. They start the whole process of inflammation: the cascade of histamine, arachidonic acid, prostaglandins, and leukotriennes.

The cytokines have to get it right. Is it a 1-alarm fire or a 5-alarm fire? If the cytokines don't call enough fire-fighters, then the house burns down. The infection takes over, the person goes septic: they could die. They call in too many fire-fighters? The fire-fighters soak the house with water, chop holes everywhere, the house collapses. Too much of an immune response leads to autoimmune diseases like ulcerative colitis, ankylosing spondylitis, multiple sclerosis, or rheumatoid arthritis. The body attacks itself.

So cytokines have to get it just right. The right number of fire-fighters, with the right skills, and the house is saved. People go back in, the house hums with life.

Anyway. Those were my thoughts on top of Mt David this morning.