Mathematical Connection between Short Telomere Induced Senescence Calculation and Mortality Rate Data.

The last 20 years have seen a surge in scientific activity and promising results in the study of aging and longevity. Many researchers have focused on telomeres, which are composed of a series of TTAGGG repeat nucleotide sequences at the ends of each chromosome. Measurements of the length of these telomere strands show that they decrease in length with increasing age, leading many authors to propose that when the length of these telomere strands decreases sufficiently, the cells enter into a state of replicative senescence, eventually leading to disease and death. These ideas are supported by evidence that short telomere length is correlated with increased mortality. In this paper, we extend this idea to make an actual calculation of the predicted mortality rate caused by short telomere length induced senescence (STLIS). We derive a simple equation for the mathematical relationship between telomere length and mortality rate. Using only three parameters based on telomere length measurement data of Canadians, we have calculated both the magnitude and the age dependence of the mortality rate for both men and women. We show that these calculated data are in good quantitative agreement with the actual number of Canadians that die. This agreement demonstrates the quantitative correlation between the mortality calculated by the STLIS model and the mortality of the major diseases of aging (e.g., cardiovascular disease, many cancers and diabetes mellitus), which dominate human mortality. This result represents significant progress in our understanding of the factors behind the cause of aging.

Randomized controlled trial of an interactive internet smoking cessation program with long-term follow-up.

BACKGROUND: Internet programs for smoking cessation are widely available but few controlled studies demonstrate long-term efficacy. PURPOSE: To determine the 13-month effectiveness of an Internet program presenting a set sequence of interactive steps, and the role of depressed affect. METHODS: In a randomized controlled trial sponsored by the American Cancer Society, a treatment condition (n = 1,106) was compared to a control site (n = 1,047). RESULTS: More treatment condition participants were abstinent (30-day point prevalence) than control site participants (12.9% vs. 10.1%, p < .05) at 13 months. This effect was greater among participants not reporting depressed affect (15.0% vs. 10.1%, p < .01). Among smokers who reported depressed affect, there was no difference in abstinence between the treatment and control conditions. CONCLUSIONS: Data support the long-term efficacy of an Internet intervention for cessation modeled on a structured, in-person treatment approach, especially for participants not experiencing daily depressed affect.