Standardized Quantification of Mast Cells in the Gastrointestinal Tract in Adults.

Background: Current data on the normal quantity of mast cells throughout the adult gastrointestinal tract are limited in several domains. These include microanatomic localization of mast cells, standardization of staining and counting methods, and reporting of microscope field of view.

Objective: To address this lack of reliable reference ranges to facilitate the study of and diagnosis of emerging mast cell-mediated diseases.

Natural Antioxidants: Multiple Mechanisms to Protect Skin From Solar Radiation.

Human skin exposed to solar ultraviolet radiation (UVR) results in a dramatic increase in the production of reactive oxygen species (ROS). The sudden increase in ROS shifts the natural balance toward a pro-oxidative state, resulting in oxidative stress. The detrimental effects of oxidative stress occur through multiple mechanisms that involve alterations to proteins and lipids, induction of inflammation, immunosuppression, DNA damage, and activation of signaling pathways that affect gene transcription, cell cycle, proliferation, and apoptosis.