Impossible science: Zombie DNA and how you're safer in a city

Whenever something goes wrong in my daily Johannesburg life, my mother — who I misguidedly call for words of comfort and solace — tells me that that’s what I get for “living in a place of wickedness”. (She harbours not-so-secret hopes of getting me to move to her bucolic paradise in deepest darkest Eastern Cape.)

However, I now have a trump card in my pocket: science, with a bit of hand-waving.

A study published in the Annals of Emergency Medicine on Wednesday shows that risk of injury-related death are significantly higher in the country/small towns than in a large city. I may be unfairly extrapolating conditions in the United States to South Africa, but I’m going to run with it any way.

“Cars, guns and drugs are the unholy trinity causing the majority of injury deaths in the US,” said lead study author Sage Myers from the University of Pennsylvania. “Although the risk of homicide is higher in big cities, the risk of unintentional injury death is 40% higher in the most rural areas than in the most urban. And overall, the rate of unintentional injury dwarfs the risk of homicide, with the rate of unintentional injury more than 15 times that of homicide among the entire population.

“This has important implications about staffing of emergency departments and trauma-care systems in rural areas, which tend to be underserved as it is.”

The researchers analysed the data of nearly 1.3-million people who died between 1999 and 2006, and found that your risk of death-by-injury was 22% higher in the sticks than in the city.

It would be difficult to extend this research into a South African context, and would require a similar study of our statistics. But I still think it is a worthy argument in defence of the city … especially if you’re accident prone.

Zombie DNA
Now, this is one of the strangest papers I’ve come across in while, and possibly the best quote from a scientist to date. Stanford University researchers have found zombie DNA — yes, zombies. Pseudogenes are considered the mutated and somewhat useless cousin of genes, the family member that you try not to make eye contact with. Although they resemble DNA sequences, they don’t make proteins (like “normal” DNA). Some people kindly refer to them as “junk DNA”.

However a team, led by Stanford professor of dermatology Howard Chang, is trying to uncover what happens in cells during inflammation. “Inflammation tells your body something is wrong,” he said. “But after it does its job of alerting immune cells to a viral or bacterial infection or spurring them to remove debris from a wound site, it has to get turned off before it causes harm to healthy tissue.”

While I’ve joked about pseudogenes being the family member avoided at parties, in reality that appears to be the case.

“Pseudogenes have been considered to be completely silent, ignored by cells’ DNA-reading machinery,” Chang said. “But we got a real surprise. When a cell is subjected to an inflammatory stress signal, it’s like Night of the Living Dead.”

That’s right — when you get inflammation in your body, a signal is sent into your cells and these zombies rise from the dead. In their droves! An army of zombies.

Although, disappointingly, the researchers have not named this flavour of pseudogene the zombie gene. More’s the pity. They have, rather whimsically, named it Lethe, after the river of forgetfulness in the underworld of Greek mythology.

And now for the practical part — the researchers found that anti-inflammatory steroid drugs, such as dexamethasone, activated Lethe, while other steroid hormones that did not contain anti-inflammatory agents, such as vitamin D and oestrogen, did not raise the zombie pseudogenes from the dead.