Radioprotective effect of melatonin on radiation-induced lung injury and lipid peroxidation in rats.

Objective: Free radicals generated by ionizing radiation attack various cellular components such as lipids. The lung is a very radiosensitive organ and its damage is a doselimiting factor in radiotherapy treatments. Melatonin (MLT), the major product of the pineal gland acts as a radioprotective agent.

Treatment of human embryonic stem cells with different combinations of priming and inducing factors toward definitive endoderm.

Despite the enormous progress in studying definitive endoderm (DE) differentiation from human embryonic stem cells (hESCs), none of the reported protocols have produced a universal, cost-effective, and competent DE with the capability to further differentiate into endodermal derivatives. In this study, by using a 2-step differentiation strategy, we have treated hESCs for 1 day with "priming" small molecules (SM), [stauprimide, NSC-308848, rapamycin (Rapa), and/or CHIR] and for the next 3 days with "inducing" SM (LY294002, cymarin, IDE1, and/or IDE2) in conjunction with activin A. In the positive control group, we treated hESCs with Wnt3a (25 ng/mL) for 1 day and activin A (100 ng/mL; W/A100-A100) for the next 3 days.