Journal: Life Sciences
Publication Date: 12/2018
Summary: The circadian rhythm orchestrates many cellular functions, such as cell division, cell migration, metabolism and numerous intracellular biological processes. The physiological changes during sleep are believed to promote a suitable microenvironment for stem cells to proliferate, migrate and differentiate. These effects are mediated either directly by circadian clock genes or indirectly via hormones and cytokines. Hormones, such as melatonin and cortisol, are secreted in response to neural optic signals and act in harmony to regulate many biological functions during sleep. Herein, we correlate the effects of the main circadian genes on the expression of certain stem cell genes responsible for the regeneration of different tissues, including bone, cartilage, skin, and intestine. We also review the effects of different hormones and cytokines on stem cell activation or suppression and their relationship to the day/night cycle. The correlation of circadian rhythm with tissue regeneration could have implications in understanding the biology of sleep and tissue regeneration and in enhancing the efficacy and timing of surgical procedures.
URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6371871/Journal: Canadian Family PhysicianPublication Date: 12/2018Summary: Ketogenic diets can help patients lose about 2 kg more than low-fat diets do at 1 year, but higher-quality studies show no difference. Weight loss peaks at about 5 months but is often not sustained. Individual weight change can vary from losing 30 kg to gaining 10 kg