What Did Van Learn Today? ... Hayflick Limit

Ever heard of the Hayflick Limit? I hadn't, until I watched a B-movie the other night on the SyFy channel named "Anacondas: The Hunt for the Blood Orchid". The premise of the movie was that they had found this flower in Borneo called a blood orchid that contained a naturally occurring chemical that was able to "work around" the Hayflick Limit. So of course they set out in search of this orchid and - given the nature of the movie - almost everyone in the movie died in the process.


What's the Hayflick Limit you ask?

The Hayflick Limit is a theory that human cells only have the ability to reproduce 40-60 times. Once the limit is reached, cell replication stops. It has been theorized that this is why people die.

So, you can imagine that if a chemical was found in the blood orchid that would work around this limit, there would be a lot of people in the scientific community clamoring to obtain it. It would be marketed as a fountain of youth and would probably be very expensive.



Well, back in reality, there is some serious interest in this theory. The limit is apparently directly linked to telomeres found at the end of our DNA strands. Every time a cell replicates, its associated telomeres are shortened by a fraction. Theoretically once your telomeres reach a certain length, this is what controls the life or death of a cell.

Interestingly, cancer cells have the ability to lengthen telomeres. Cancer cells turn on an enzyme called telomerase which rather than shorten telomeres actually lengthens them - essentially having the effect of making them "immortal". Scientists are now looking into the possibility of using this enzyme to extend life.

It's interesting what you can learn from cheesy movies.

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What did Van learn today?

There apparently is a difference between chiggers and jiggers. Jiggers are the ones that burrow into your skin. Chiggers do not, but they do bite. Jiggers are only found in the tropical regions. Chiggers are found in cooler regions - like in the US.


Both blemishes itch.

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What Sweetens Toothpaste?

Today, I called to reschedule a dentist appointment that I would have had to miss for being on vacation. Oddly, the office had had two cancellations today and so they were able to fit me in today (within 2 hours of my call). That's Frederick for you. We have lots of medical professionals and - I guess - not as many patients to go around. It is much easier to get into see a doctor in Frederick than it was when I lived in Alexandria, VA.


Anyway ... I was sitting in the chair and I asked the dentist something that I had personally been curious about for a while. What do the toothpaste companies use to sweeten their product? Surely, it must not be sugar, since dentists have always said how bad it is for your teeth. I have looked on toothpaste tubes at home for the ingredients, but I guess since it is not a food product, there is no requirement to reveal the ingredients. They do often go out of their way to tell you that it contains fluoride, however.

The dentist had no answer for me, though she was reasonably sure that they use some form of artificial sweetener. It seems to me that this should be disclosed. What if you are allergic to whatever they are using?

It turns out there is quite a lot in toothpaste. Wikipedia lists toothpaste as potentially having: Abrasives, Fluorides, Surfactants, Antibacterial agents, Flavorants, Remineralizers and Miscellaneous components (which can include: glycerol, sorbitol, xylitol, or related derivatives, such as 1,2-propylene glycol and polyethyleneglycol). I would assume from the names of those last ingredients that those are the sweeteners.

So there you have it. Maybe it's possible that the reason they don't list the ingredients is because there is no room on the tube!

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Trying to blog from my iPad

You may have noticed that I don't blog very much. This is mostly due to the fact that when I get home at night I feel more like playing games or doing some other leisurely activity then anything serious. Writing falls into that "serious" category. So ... I thought I would give this a shot. I downloaded this cool app for my iPad that allows me to compose a blog - say, while my computer is processing or when I have more energy at lunch. I can save drafts to work on it later, post pictures from my iPad photo gallery and do special formatting, things I could not do as easily through an email post.

So, here ya go. Here's a picture from my iPad that I downloaded from a science article I read elsewhere (credit goes to ElectronCafe). I liked it so much, I made it my main page on my iPad.






It illustrates the true nature of science versus the public perception of science as seen through for example MythBusters.

So long for now.

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