Analysis of telomere lengths in cloned sheep

Telomere dynamics in induced pluripotent stem cells: Potentials for human disease modeling

Recent advances in reprograming somatic cells from normal and diseased tissues into induced pluripotent stem cells (iPSCs) provide exciting possibilities for generating renewed tissues for disease modeling and therapy. However, questions remain on whether iPSCs still retain certain markers (e.g. aging) of the original somatic cells that could limit their replicative potential and utility. A reliable biological marker for measuring cellular aging is telomere length, which is maintained by a specialized form of cellular polymerase known as telomerase. Telomerase is composed of the cellular reverse transcriptase protein, its integral RNA component, and other cellular proteins (e.g. dyskerin). Mutations in any of these components of telomerase can lead to a severe form of marrow deficiency known as dyskeratosis congenita (DC). This review summarizes recent findings on the effect of cellular reprograming via iPS of normal or DC patient-derived tissues on telomerase function and consequently on telomere length maintenance and cellular aging. The potentials and challenges of using iPSCs in a clinical setting will also be discussed.

Human Health, Well-Being, and Global Ecological Scenarios

This article categorizes four kinds of adverse effects to human health caused by ecosystem change: direct, mediated, modulated, and systems failure. The effects are categorized on their scale, complexity, and lag-time. Some but not all of these can be classified as resulting from reduced ecosystem services. The articles also explores the impacts that different socioeconomic-ecologic scenarios are likely to have on human health and how changes to human health may, in turn, influence the unfolding of four different plausible future scenarios. We provide examples to show that our categorization is a useful taxonomy for understanding the complex relationships between ecosystems and human well-being and for predicting how future ecosystem changes may affect human health.