People have known for a long time that stress is bad for you. Having good social support isn’t just, you know, the reason to live, it’s also good for your health. The guy who did this study worked out a link in the biological chain between stress and death.

The molecule he was looking at is called a transcription factor. A transcription factor is a little protein that grabs onto a strand of DNA near a gene and says, “Hey, transcribe this gene!” In this case, the transcription factor is activated by a stress hormone and turns on a gene that makes a protein involved in inflammation, part of the immune response. Inflammation is fantastic for, like, healing cuts, but we modern humans tend to turn it on and leave it on, which leads to heart disease and other nasty stuff.

So that’s what the story’s about. This was my first time writing for the Chronicle – my editor there is a former colleague from U.S. News & World Report, and it was fun to be reunited for this story.

At the very least, you should look at the great portrait they took of the scientist. He works at UCLA, but he happened to be on campus at Stanford (my first grad school alma mater) the week they needed to take a picture of him, so this is a picture of him with one of the many Rodins that litter campus. Anyone recognize the sculpture? It’s reasonably famous.

Yes, your pets are trying to kill you. Ok, not kill you, and they mostly don’t do it on purpose, but they really are dangerous. Researchers at the CDC analyzed emergency room data and came up with estimates for how many injuries caused by falls are related to pets. A lot, it turns out. This weekend I met someone who’d gotten pretty banged up by falling over cats on the stairs. Yikes. Here’s the story.

The other story is about dogs, but it’s also about a theory in evolutionary biology. The question is how personalities evolved – all kinds of animals have them, and some biologists think they may have come about along with a few different life plans. One is sort of the “live fast, die young” plan, where you live like a pop star, reproduce early, take risks, and die young. This is thought to be associated with bolder personalities. The other is a more cautious, longer life. The guy in my story thought he’d look at dogs to see if these relationships are true across breeds with different personalities.

photo: by me

This is related to a shift in how people think about biology. For decades after DNA was discovered, everyone was really worked up about the genetic code, and how genes are a blueprint for everything. But the truth is, of course, much more complicated. Just because you have a gene doesn’t mean that it’s being expressed. It might be turned off entirely, or only weakly expressed, or only expressed in some cells and not others. Epigenetics is about looking at differences in how genes are expressed (turned into proteins).

You can understand the blog post even if that doesn’t make sense

Fun fact: They aren’t test tube babies, they’re actually petri dish babies.

Another fun fact: The picture with my story is of an egg being fertilized by intracytoplasmic sperm injection (ICSI) (“icksee”). While in vitro fertilization was developed to get around female infertility, ICSI is for male infertility. As long as the guy is still making some sperm, you can fish them out and inject one right into the egg.

The thinking on tooth decay has changed a lot in the last few decades. The people who study oral health used to focus on one organism, Streptococcus mutans, as the culprit in cavities, churning out the acid that destroys enamel.

But now they realize that tons of microbes, from hundreds of species, live in your mouth. Your mouth is like a tropical rainforest, but with Streptococcus and Bifidobacterium and Lactobacillus instead of fig trees and monkeys and toucans. People who study dental disease – and intestinal disease, too – have realized they need to think about the mouth and gut like an ecological system.

The advances in molecular biology in the last couple decades have totally revolutionized the study of microorganisms. In the old days, if you wanted to know what was growing in someone’s mouth, you had to take a sample of goo, then grow it up in the lab to see what you had. The problem is, a lot of bacteria are hard to culture. They’re finicky eaters. Some won’t grow in the presence of oxygen. But now, scientists can take that goo, extract DNA, and census the bugs without having to culture them.

That means scientists are getting more of a handle on all the different jungles in your body. You are so majorly outnumbered by bacteria. There’s one of you and a bazillion of them. They live in your intestines, in your nose, in your mouth, on your skin. You’re even outnumbered at the cell level. There are more bacterial cells in and on your body than human cells. Don’t worry, you’re still mostly human if you measure by volume; bacterial cells are much, much smaller than mammal cells.

Photo: Bifidobacterium dentium, courtesy of the Ventura Lab

This was in front of a teaching hospital. My guess is they’re for people to practice doing intubations. (Anybody know for sure?)

Today I wrote for ScienceNOW about a new study on arsenic in Bangladesh. Some researchers from MIT think they’ve figured out why some water has more arsenic than other water. Special microbes dissolve the arsenic from the sediment into the water, and they need a carbon source – so the scientists who study arsenic in Southeast Asia are arguing over where that carbon comes from. The new study gives one answer to that question. Read my story here.

In the meantime, people in Bangladesh need low-arsenic water. Filters work, but they’re expensive and need maintenance. Deeper wells tap into deeper aquifers with less arsenic, but they’re also expensive, and as water is sucked out of the deep aquifer, higher-arsenic water could sink down from above.

I thought it was fascinating that the people of Bangladesh have traded deaths from water-borne disease for long-term cancer risks, but I talked to an epidemiologist, Allan Smith at Berkeley, who figures it’s not worth arguing over which was worse. “For me, it’s not something I’ve ever cared to try to quantify. Clearly we want to reduce the deaths from gastroenteritis and clearly we want to reduce the deaths from arsenic. We should just move forward.”

The secretary calls and says, “Frau Fields? Do you speak German?” And I said, “More or less.” She said, “I have a reader on the line, I’ll transfer you.” And I was like, uhh, uhh, and there he was. Yesterday the 19-year-old intern and I co-wrote a story about chronic kidney disease and kidney failure. (Really, it was mostly her – she’s young, but she’s good. Also, she speaks German and can interview people.)

The nice man told me he’d read my article in today’s paper about kidney disease, and I’d mentioned a test to detect protein in the urine. Well, yesterday his wife had a blood test at the hospital, and he had the test results, and could I tell him what the line about protein meant?

Uhhhhh….no. No, I could not tell him that. We chatted a bit about tests for kidney function, agreed that it was best to talk to the doctor (he relayed this to his wife) and he thanked me for such an informative article and told me to keep up the good work.

I pretty much feel like now I am a German superstar, although I didn’t understand everything he said, I stumbled a bit while talking, and, yeah, I totally couldn’t answer his question. Man, I haven’t gotten a call from a reader in forever. It’s the last day of my fellowship – not a bad way to end.

There it is, my friends. This is the value of life overseas: learning that, whatever ails your digestive system, what you really need is pretzel sticks and coke. Two doctors did ask me if I was drinking coke and seemed a little surprised that I wasn’t. I look forward to trying the local folk remedy this afternoon.