HIF-1-dependent stromal adaptation to ischemia mediates in vivo tumor radiation resistance.

Purpose: Hypoxia-inducible factor 1 (HIF-1) promotes cancer cell survival and tumor progression. The specific role played by HIF-1 and tumor-stromal interactions toward determining tumor resistance to radiation treatment remains undefined. We applied a multimodality preclinical imaging platform to mechanistically characterize tumor response to radiation, with a focus on HIF-1-dependent resistance pathways.

Successful incorporation of tissue-engineered porcine small-intestinal submucosa as substitute flexor tendon graft is mediated by elevated TGF-beta1 expression in the rabbit.

Purpose: Ideal tendon repair materials combine minimal donor-site morbidity and ready availability with excellent healing and postoperative function. Bioengineered porcine small-intestinal submucosa (SIS) was compared with tendon autografts as a potential human flexor tendon graft substitute.

Methods: Rabbit zone II flexor digitorum profundus segments were excised in 40 rabbits.