Free-grazing ducks in rice paddies are a critical factor in the spread and persistence of avian influenza.

The results demonstrate an association between EBV reactivation and disease activity in MS patients over time, and suggest that EBV might play an indirect role in MS as an activator of the underlying disease process.

Transforming growth factor ␤ (TGF-␤), a pleiotropic cytokine that regulates cell growth and differentiation, is secreted by many human tumors and markedly inhibits tumor-specific cellular immunity. Tumors can avoid the differentiating and apoptotic effects of TGF-␤ by expressing a nonfunctional TGF-␤ receptor. We have determined whether this immune evasion strategy can be manipulated to shield tumor-specific cytotoxic T lymphocytes (CTLs) from the inhibitory effects of tumor-derived TGF-␤. As our model we used Epstein-Barr virus (

Graft-versus-host disease (GVHD