Pelvic fistulas complicating pelvic surgery or diseases: spectrum of imaging findings.

Pelvic fistulas may result from obstetric complications, inflammatory bowel disease, pelvic malignancy, pelvic radiation therapy, pelvic surgery, or other traumatic causes, and their symptoms may be distressing. In our experience, various types of pelvic fistulas are identified after pelvic disease or pelvic surgery. Because of its close proximity, the majority of such fistulas occur in the pelvic cavity and include the vesicovaginal, vesicouterine, vesicoenteric, ureterovaginal, ureteroenteric and enterovaginal type. The purpose of this article is to illustrate the spectrum of imaging features of pelvic fistulas.

Polycomb group repression is blocked by the Drosophila suppressor of Hairy-wing [su(Hw)] insulator.

The suppressor of Hairy-wing [SU(HW)] binding region disrupts communication between a large number of enhancers and promoters and protects transgenes from chromosomal position effects. These properties classify the SU(HW) binding region as an insulator. While enhancers are blocked in a general manner, protection from repressors appears to be more variable. In these studies, we address whether repression resulting from the Polycomb group genes can be blocked by the SU(HW) binding region. The effects of this binding region on repression established by an Ultrabithorax Polycomb group Response Element were examined. A transposon carrying two reporter genes, the yellow and white genes, was used so that repression and insulation could be assayed simultaneously. We demonstrate that the SU(HW) binding region is effective at preventing Polycomb group repression. These studies suggest that one role of the su(Hw) protein may be to restrict the range of action of repressors, such as the Polycomb group proteins, throughout the euchromatic regions of the genome.