Imaging of pediatric head and neck rhabdomyosarcomas with emphasis on magnetic resonance imaging and a review of the literature

In the mouse, the initiation of the attachment reaction between the blastocyst trophectoderm and luminal epithelium of the receptive uterus occurs in the evening (2200-2300 h) of day 4 of pregnancy (day 1 = vaginal plug) and is followed by proliferation and differentiation of stromal cells into decidual cells at the sites of blastocyst attachment. This investigation demonstrates that an inappropriate expression of the human transforming growth factor alpha (hTGF-alpha) transgene in the uterus under the direction of a mouse metallothionein-I promoter downregulates uterine expression of TGF-beta receptor subtypes and delays the initiation of implantation (attachment reaction) resulting in delayed parturition. This delay in the attachment reaction is accompanied by deferred uterine expression of amphiregulin. The results suggest that a coordinated 'cross-talk' between the signaling pathways executed by epidermal growth factor-like growth factors and TGF-beta 5 is important for the normal implantation process.