INTERESTING TIMES

"The search for unpolluted drinking water is as old as civilization itself. As soon as there were mass human settlements, waterborne diseases like dysentery became a crucial population bottleneck. For much of human history, the solution to this chronic public-health issue was not purifying the water supply. The solution was to drink alcohol. In a community lacking pure-water supplies, the closest thing to "pure" fluid was alcohol. Whatever health risks were posed by beer (and later wine) in the early days of agrarian settlements were more than offset by alcohol's antibacterial properties. Dying of cirrhosis of the liver in your forties was better than dying of dysentery in your twenties. Many genetically minded historians believe that the confluence of urban living and the discovery of alcohol created a massive selection pressure on the genes of all humans who abandoned the hunter-gatherer lifestyle. Alcohol, after all, is a deadly poison and notoriously addictive. To digest large quantities of it, you need to be able to boost production of enzymes called alcohol dehydrogenases, a trait regulated by a set of genes on chromosome four in human DNA. Many early agrarians lacked that trait, and thus were genetically incapable of "holding their liquor." Consequently, many of them died childless at an early age, either from alcohol abuse or from waterborne diseases. Over generations, the gene pool of the first farmers became increasingly dominated by individuals who could drink beer on a regular basis. Most of the world population today is made up of descendants of those early beer drinkers, and we have largely inherited their genetic tolerance for alcohol. (The same is true of lactose tolerance, which went from a rare genetic trait to the mainstream among descendants of the herders, thanks to domestication of livestock.) The descendants of hunter gatherers--like many Native Americans or Australian Aborigines--were never forced through this genetic bottleneck, and so today they show disproportionate rates of alcoholism. The chronic drinking problem in Native American populations has been blamed on everything from the weak "Indian constitution" to the humiliating abuses of the U.S. reservation system. But their alcohol intolerance most likely has another explanation: their ancestors didn't live in towns."
--Steven Johnson, in The Ghost Map, pages 103-4.

and including Persistent Organic Pollutants and Plastics
Kids with exposure to nature have less ADHD
( notes )

Funny how exciting a revelation like this can be to me. I finally understand why in alcoholic liver disease the AST is often elevated more than the ALT. Also the GGT may be normal. Why? Because both AST and GGT are dependent on vitamin B6 for their manufacture, and that particular nutrient is depleted by heavy drinking. Ha. Why didn't somebody tell me that years ago?

Methotraxate is one of the drugs often used in chemotherapy. It interferes with folate metabolism by acting as a competitive inhibitor of the enzyme dihydrofolate reductase. Without this enzyme, the cells are starved for tetrahydrofolate, and unable to make purines (adenine, guanine) and dTPM. This is especially toxic to fast-growing cells, like cancer cells.

How does a cancer become resistant to this drug?
( answer )

1. Vitamins: small, low molecular weight, organic mols required for normal function, most we don't synthesize, classified as fat or water soluble.

Which vitamins are derived from isopentenyl pyrophosphate? Vitamin A (terpene), D, E, K, cholesterol
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These notes were posted friends-only until the night before the assignment is due.
( Timothy Vail's Chem 360 Take Home Quiz #3 Spring 2007 )