Tuesday, October 17, 2006

Staph in the Brain: Part 2

Well, that headache went away. I guess that means I dont have a colony of Staph eating my brain. **sigh** Oh well. hehehehehe!

As promised, I read through one of Dr. Kielians papers:

The role of Toll-like receptors in CNS response to microbial challenge

Sure they do a better job of explaining their research than I can, but heres my summary anyway--
There are these great cells in your brain-- astrocytes and microglia, that act as 'gatekeepers.' They keep bad stuff out. But sometimes, despite their best efforts, something does get through. So theyve got these receptors in their membrane that detect 'bad' stuff floating around called 'Toll like receptors.' Lots of families and lots of kinds of these receptors that non-specifically detect foreign stuff floating around your brain: Double stranded RNA (a virus got in!), PGN (a bacteria got in!), that sort of thing.

They then proceed to freak out.

When they detect something foreign has gotten past the blood-brain barrier, they start the inflammatory response, releasing cellular messengers that call white blood cells to the brain (thats why the ball of bacteria in your brain will also be filled with puss. YEAH!). One of the problems with a Staph infection in the brain (other than the fact Staph is in your brain), is that long after the bacteria are dead, their body parts are still floating around. The astrocytes and glial cells think that means there is still bacteria eating your brain, and they call up MORE white blood cells. This causes 'bystander injury,' where normal neurons are killed because of an over-active inflammatory response.

Dr. Kielian is hoping that their characterization of this pathway with Staph can help us better understand other diseases like HIV dementia and MS, which might be caused or propogated by this Toll receptor response.

Im going to think of this every time I get a headache now. Ugh.

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