How many cigarettes is it safe to smoke?

ugg boots comparing the lung biopsies from regular smokers to those from nonsmokers, the researchers identified 372 genes whose expression was triggered by tobacco smoke. Then they checked to see what those genes were doing in the occasional smokers. It turned out that 128 of those genes (34%) had been activated -- presumably by cigarettes -- including 41 (11%) that were “significantly modified,” according to the study.

cheap ugg boots further, the researchers found that the two groups of genes that responded most strongly in the occasional smokers were the same two groups that are most active in regular smokers. “These changes in gene expression are likely the earliest biologic abnormalities in the small airway epithelium that lead to clinically detectable lung disease,” they wrote.

buy ugg boots the researchers checked to see how much nicotine and cotinine had to be in the urine before changes in the lung cell genes were noticeable. For nicotine, that level was a mere 1.8 nanograms per milliliter too low to be picked up in tests. In other words, of nicotine that was considered harmless, the researchers wrote. For cotinine, the threshold was 11 ng/ml, only slightly higher than the amount that the most sensitive tests can detect.