x(t) = x0*exp(k*t)

Day +15 (D 153)

I'd like to start off today's blog with a bit of a rant about Google. I know that blogger is technically a "open beta", which means that the software is continuously evolving...but come on! They had a perfectly simple way of uploading photos and integrating them with text. Apparently it was just too easy so they decided to change it, I guess just to see who can keep up. My Father has often uttered the vilest insults at Microsoft whenever they introduced a new version of Windows or Excel, and I always found it a bit on the amusing side. I guess today is my day for payback, or perhaps my level of patience with software is just not what it used to be...

...Picasa sucks.

Anyway, you are probably wondering what the heck the title of today's blog post is right? It's a mathematical expression of exponential growth as a function of time. It basically means that over a period of time a population will expand according to its growth constant (k), initial population (x0) and the amount of time (t) it grows.

I spent some time working out a very simple growth model for Ann's new white cells with a few basic assumptions. x0 = 0.1 K/uL, r=14 hours, k=ln(1+r/100) and t ranging from 0 to 500 hours. I was going to publish the really neat chart from Excel and compare it to Ann's actual counts but no such luck (thanks Google). Everyone will just have to use their imaginations.

The model is not perfect because it doesn't accurately predict the lifespan of a white blood cell. However, I think it's good enough to give me an educated guess as to how long it will take to get Ann's WBC count up to 1.0 K/uL. The magic date for which will be on or around 6/20/07 according to my calcs.

Now that I have bored almost everyone but the engineers and scientists in our audience to tears I'll recap the events of today.

Without either of us knowing it Ann has gathered quite a following here. According to the visiting physician, Ann is the "star of the floor". Meaning that Ann's counts are recovering much faster than they expected after a cord blood transplant. The general thinking is that this is because she is part of the expanded arm of the transplant study. The quick response is most likely the cells that where nucleated prior to transplant.

These nucleated cells should be more mature than the ones harvested directly from the cords. So they will have be able to colonize Ann's bones more quickly and provide immune coverage while the two plain cords take hold and grow to maturity. Ann based on today's blood results I would have to say it appears to be working. Ann's WBC count was at 0.5 K/uL and her RBC count didn't fall for the first time in a week.

In non medical news we got word today that we will have to move out of the apartment we have been staying at. The church charity we have been renting from has been absolutely great, but our lease was limited to 6 months total and it runs out in July. Luckily I managed to find a newly renovated place that is a comparable price and actually closer to MDA. On the down side we will have to furnish it, but I think we can do that with a trip or two to target and maybe the salvation army.

Hopefully I will get Google's Picasa working and we will be able to post pictures again.