Comparison of single layer staple closure versus double layer hand-sewn closure for equine pelvic flexure enterotomy.

Our objective was to compare thoracoabdominal (TA Premium™ 90) stapled enterotomy closure to traditional hand-sewn closure, using time to perform the technique, luminal diameter, and bursting pressure in ex-vivo specimens. The pelvic flexures of 13 client-owned horses were harvested. Each pelvic flexure had 1 enterotomy performed; 6 were closed via staples, 7 closures were hand-sewn. Luminal diameter at the enterotomy site was assessed via contrast radiography performed pre-and post-enterotomy. Bursting pressure of the closure was assessed by continuous manometry during rapid infusion. Time to perform stapled closure was significantly shorter than hand-sewn closure (P < 0.0001). Percent reduction of luminal diameters was significantly decreased in stapled specimens (P = 0.034). There was no significant difference in bursting strength between closure techniques (P = 0.196). In conclusion, stapled enterotomy closure offers statistically significant reduction in closure time and better maintains pre-enterotomy luminal diameter without reducing biomechanical strength, compared to a double layer hand-sewn closure.

Requirement for estrogen receptor alpha in a mouse model for human papillomavirus-associated cervical cancer.

The majority of human cervical cancers are associated with the high-risk human papillomaviruses (HPV), which encode the potent E6 and E7 oncogenes. On prolonged treatment with physiologic levels of exogenous estrogen, K14E7 transgenic mice expressing HPV-16 E7 oncoprotein in their squamous epithelia succumb to uterine cervical cancer. Furthermore, prolonged withdrawal of exogenous estrogen results in complete or partial regression of tumors in this mouse model. In the current study, we investigated whether estrogen receptor alpha (ERalpha) is required for the development of cervical cancer in K14E7 transgenic mice. We show that exogenous estrogen fails to promote either dysplasia or cervical cancer in K14E7/ERalpha-/- mice despite the continued presence of the presumed cervical cancer precursor cell type, reserve cells, and evidence for E7 expression therein. We also observed that cervical cancers in our mouse models are strictly associated with atypical squamous metaplasia (ASM), which is believed to be the precursor for cervical cancer in women. Consistently, E7 and exogenous estrogen failed to promote ASM in the absence of ERalpha. We conclude that ERalpha plays a crucial role at an early stage of cervical carcinogenesis in this mouse model.