Options on fibroid morcellation: a literature review.

In laparoscopy, specimens have to be removed from the abdominal cavity. If the trocar opening or the vaginal outlet is insufficient to pass the specimen, the specimen needs to be reduced. The power morcellator is an instrument with a fast rotating cylindrical knife which aims to divide the tissue into smaller pieces or fragments. The Food and Drug Administration (FDA) issued a press release in April 2014 that discouraged the use of these power morcellators. This article has the objective to review the literature related to complications by power morcellation of uterine fibroids in laparoscopy and offer recommendations to laparoscopic surgeons in gynaecology. This project was initiated by the executive board of the European Society of Gynaecological Endoscopy. A steering committee on fibroid morcellation was installed and experienced ESGE members requested to chair an action group to address distinct clinical questions. Clinical questions were formulated with regards to the sarcoma risk in presumed uterine fibroids, diagnosis of sarcoma, complications of morcellation and future research. A literature review on the different subjects was conducted, systematic if appropriate and feasible. It was concluded that the true prevalence of uterine sarcoma in presumed fibroids is not known given the wide range of prevalences (0.45-0.014 %) from meta-analyses mainly based on retrospective trials. Age and certain imaging characteristics such as 'lacunes' suggesting necrosis and increased central vascularisation of the tumour are associated with a higher risk of uterine sarcoma, although the risks remain low. There is not enough evidence to estimate this risk in individual patients. Complications of morcellation are rare. Reported are direct morcellation injuries to vessels and bowel, the development of so-called parasitic fibroids requiring reintervention and the spread of sarcoma cells in the abdominal cavity, which may possibly or even likely upstaging the disease. Momentarily in-bag morcellation is investigated as it may possibly prevent morcellation complications. Because of lack of evidence, this literature review cannot give strong recommendations but offers only options which are condensed in a flow chart. Prospective data collection may clarify the issue on sarcoma risk in presumed fibroids and technology to extract tissue laparoscopically from the abdominal cavity should be perfected.

Structure of the retinoid X receptor α-liver X receptor ß (RXRα-LXRß) heterodimer on DNA.

Nuclear receptors (NRs) are conditional transcription factors with common multidomain organization that bind diverse DNA elements. How DNA sequences influence NR conformation is poorly understood. Here we report the crystal structure of the human retinoid X receptor α-liver X receptor ß (RXRα-LXRß) heterodimer on its cognate element, an AGGTCA direct repeat spaced by 4 nt. The complex has an extended X-shaped arrangement, with DNA- and ligand-binding domains crossed, in contrast to the parallel domain arrangement of other NRs that bind an AGGTCA direct repeat spaced by 1 nt. The LXRß core binds DNA via canonical contacts and auxiliary DNA contacts that enhance affinity for the response element. Comparisons of RXRα-LXRßs in the crystal asymmetric unit and with previous NR structures reveal flexibility in NR organization and suggest a role for RXRα in adaptation of heterodimeric complexes to DNA.