Tuesday, January 29, 2008

We're all gonna die.

Title: Good Germs, Bad Germs: Health and Survival in a Bacterial World
Author: Jessica Snyder Sachs

This book was both fantastic and terrifying. It's kindof like an intro course on bacteria, slightly helped by my prior scientific knowledge, but it definitely wasn't required.

The various sections in the book include one discussing the normal bacteria that live in and on the human body, most of which are helpful, and how when we take antibiotics that are (1) too broad, or (2) not even needed (I'm sure you know someone who insisits on telling the doctor what's wrong with them, and insisting on what they need - say, antibiotics when they have a cold, which is caused by a virus) even worse things can happen. I've seen it - there's one known as C. diff. that causes severe diarrhea and usually is picked up during a hospital visit, because if all the good bacteria in your body are wiped out, the bad ones can take up residence. You want to talk scary, there's all kinds of infections running rampant in nursing homes. Apparently someone died of GANGRENE FROM A BEDSORE in the one where my grandmother lives last week.

There's so many problems in our world involving bacteria and antibiotics. For example, farmers discovered a few decades ago that several antibiotics promote growth of animals. So they feed their livestock high doses of these antibiotics solely for growth purposes (!!!), in addition to the numerous antibiotics they're fed for "prevention" of infections (which of course means that any infections that set in will be resistant to all the drugs the farmers are already providing).

Bacteria are incredibly versatile. If one has a slight evolutionary advantage allowing it to survive a course of antibiotics, it'll populate and, before long, render that particular antibiotic obsolete. Entire classes of antibiotics have become useless since the 1950's. The practice of giving animals antibiotics that could also be used for human treatments means that by the time we try to use them on humans they're useless (this happened in Europe in the 1990's).

Big drug companies aren't too enthusiastic about researching new antibiotics, since as soon as they're put into use, they're on a course for obsolesence, meaning no more profits. And then there's the big scare stories in the news about MRSA (methicillin-resistant Staphlococcus aureus), which isn't actually resistant to everything, but definitely resistant to the most common treatments for infection, and by the time they figure out what's going on, you're dead.

I kept flagging pages as interesting while reading this. A few examples:

Recent research suggests that in an environment where deadly infections remain rare, natural seelction favors a mild, or tolerant, immuine response - because it decrease a woman's risk of miscarriage up to sisteenfold. A budding embryo, after all, is the ultimate "foreign" invader and demans enormous tolerance from the immune system if a pregnancy is to succeed. By contrast, life in communities that are plagued by infection strongly favors the survival of babies who are genetically equipped for a brutally strong inflammatory response. the increased risk of miscarriage becomes a small price to pay for higher odds that a child will at least survive to reach reproductive age. (p. 153)

For oral antibiotics, which get absorbed through the intestinal tract, the challenge is the opposite: to keep the drugs inactive until after they get absorbed. Drugs that can pull off this trick are known as "prodrugs," and familiar nonantibiotic examples include Levodopa, a Parkinson's drug that begins working only after it crosses into the brain, and cancer chemotherapies that become toxic only after entering tumors. Some of the first prodrug antibiotics came about itn the early 1990s, whieh biochemists began tinkering with the powerful new cephalosporin drugs to improve their absorption so they could be taken in pill form instead of injected. The chemists found they could greatly improve absorption by attaching a small compound (an ester) to a piece of the latger cephalosporin molecule. Further tinkering produced esters that conveniently fell away again as soon as the drug passed into the intestinal tissue, so as not to interfere with its action.
The fortuitous side effect was a group of drugs that did not produce intestinal "upset" - that is, the kind of diarrhea that antibiotics provoke when they raze our digestive bacteria. Some prodrug antibiotics turned out to have the additional advantage of being excreted primarily in urine rather than in intestinal bile, so they bypassed the intestinal tract on the way out as well as the way in. ... But prodrug antibiotics have yet to be introduced in the United States, where few physicians have heard of them. (pp. 164-165)

All those commericals for cheese and yogurts that help your digestion? They're probiotics, intended to increase the populations of the good bacterial in your intestines. Even though people aren't being properly educated as to how they work, it's nice to see the increase in their use. For quite a while now other probiotics have been available OTC in health food/supplement stores (The C. diff. I mentioned earlier? The grandma in a nursing home has gotten it pretty much each time she's been hospitalized; my mom did some research, found out about probiotics, and very effectively supplemented the prescribed treatments with probiotics.)

In case you didn't figure it out, I really enjoyed this book, even though I'm now afraid to eat pretty much any processed foods. And I plan to track down the author's earlier book, which appears to be about forensics and corpses (yay!).

And now to take things back to a more familiar (ket-type) level:

A while ago (before this blog got started) I started reading a book. Yes, it was a trashy novel. But the tie-in here is that the heroine's late husband, the father of her twin boys, had died of a random staph infection he picked up at his rock climbing gym. See, they had met through climbing, but once their sons were born, she thought it was too dangerous to go to the gym and climb, and he wanted to go one last time, and she was right! (That was my first problem with the book. Any book that suggests that rock climbing will kill you is not appealing to me, especially when the author obviously knows nothing more than how to insert climbing terms into a sentence). And then somehow seven years later this powerful-corporate-type woman is running a B&B in the middle of nowhere so she can be with the kids all the time, and somehow there's a hitman staying there, and other people trying to kill him, and somehow the local handyman comes to the rescue, and that's about when I gave up. Not on the contrived plot, though that wasn't helping things, but because there was all this talk about how he didn't need a secondary education, that being blue-colar was so admirable, and she needs to realize that, and so on. The sentiment is fine, but the way the author was so heavy-handed about it really killed the book. That, and killing off a perfectly nice-sounding climber. And no, there's no good reason for me to still remember even this much about the story.

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posted by ket at 3:39 PM


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