Monte Carlo simulation of irradiation and killing in three-dimensional cell populations with lognormal cellular uptake of radioactivity.

Purpose: The biological response of tissue exposed to radiations emitted by internal radioactivity is often correlated with the mean absorbed dose to a tissue element. However, experimental studies show that even when the mean absorbed dose to the tissue element is constant, the response of the cell population within the tissue element can vary significantly depending on the distribution of radioactivity at the cellular and multicellular levels. The present work develops theoretical models to simulate these observations.

Redox regulatory mechanism of transnitrosylation by thioredoxin.

Transnitrosylation and denitrosylation are emerging as key post-translational modification events in regulating both normal physiology and a wide spectrum of human diseases. Thioredoxin 1 (Trx1) is a conserved antioxidant that functions as a classic disulfide reductase. It also catalyzes the transnitrosylation or denitrosylation of caspase 3 (Casp3), underscoring its central role in determining Casp3 nitrosylation specificity.