NADH inhibition of SIRT1 links energy state to transcription during time-restricted feeding.

In mammals, circadian rhythms are entrained to the light cycle and drive daily oscillations in levels of NAD, a cosubstrate of the class III histone deacetylase sirtuin 1 (SIRT1) that associates with clock transcription factors. Although NAD also participates in redox reactions, the extent to which NAD(H) couples nutrient state with circadian transcriptional cycles remains unknown. Here we show that nocturnal animals subjected to time-restricted feeding of a calorie-restricted diet (TRF-CR) only during night-time display reduced body temperature and elevated hepatic NADH during daytime.

Primum non nocere: Utility and outcomes of pediatric breast ultrasound.

Purpose: To assess the use and outcomes of ultrasound for the evaluation of breast signs and symptoms in pediatric females.

Methods: A retrospective database review identified all patients ≤18-years-old who underwent breast ultrasound at an academic institution over a 20-year period. Each symptomatic site was designated a case and analyses were performed on each case.