A critical review finds styrene lacks direct endocrine disruptor activity.

The European Commission lists styrene (S) as an endocrine disruptor based primarily on reports of increased prolactin (PRL) levels in S-exposed workers. The US Environmental Protection Agency included S in its list of chemicals to be tested for endocrine activity. Therefore, the database of S for potential endocrine activity is assessed. In vitro and in vivo screening studies, as well as non-guideline and guideline investigations in experimental animals indicate that S is not associated with (anti)estrogenic, (anti)androgenic, or thyroid-modulating activity or with an endocrine activity that may be relevant for the environment. Studies in exposed workers have suggested elevated PRL levels that have been further examined in a series of human and animal investigations. While there is only one definitively known physiological function of PRL, namely stimulation of milk production, many normal stress situations may lead to elevations without any chemical exposure. Animal studies on various aspects of dopamine (DA), the PRL-regulating neurotransmitter, in the central nervous system did not give mechanistic explanations on how S may affect PRL levels. Overall, a neuroendocrine disruption of PRL regulation cannot be deduced from a large experimental database. The effects in workers could not consistently be reproduced in experimental animals and the findings in humans represented acute reversible effects clearly below clinical and pathological levels. Therefore, unspecific acute workplace-related stress is proposed as an alternative mode of action for elevated PRL levels in workers.

Epidural Interlay Graft for Pituitary Surgery: A 4-Year Institutional Experience.

Objective Sellar repair techniques with varying complexity and effectiveness have been employed to reduce the incidence of postoperative cerebrospinal fluid (CSF) leaks following endoscopic transsphenoidal pituitary surgery. This study describes our institutional experience with a minimalistic, highly effective approach to sellar repair. Methods The authors performed a retrospective review of consecutive cases of transsphenoidal pituitary surgery performed at our institution. All included subjects underwent sellar repair with an epidural interlay graft. Relationships between patient and tumor characteristics, incidence of CSF leak, adjunct repair techniques, and endocrine outcomes were examined. Results Three hundred and thirty-four (334) cases were included. Intraoperative CSF leak was encountered in 116 cases (34.7%), and postoperative CSF leak occurred only once (0.3%) early in the series. Seventy intraoperative CSF leaks were successfully repaired with an epidural interlay alone, including 13 high-flow leaks. Our rate of fat graft use (1.2%), nasoseptal flap (3.0%), and lumbar drain placement (6.6%) in the second half of the series showed a significant decline compared with the first half, indicating increased reliance on the interlay graft over time. Our 65% functional macroadenoma remission rate compares favorably with large historical series. Conclusion Simple sellar repair using an epidural interlay graft is highly effective in preventing postoperative CSF leaks, including cases of high-flow intraoperative leaks. More complex repair techniques are reserved for select high-risk cases or those with inadequate sellar bony ledges. With this technique, there has been no postoperative CSF leak at our institution in over 300 consecutive transsphenoidal pituitary surgeries.