Hirschsprung disease (HSCR) is a partially penetrant oligogenic birth defect that occurs when enteric nervous system (ENS) precursors fail to colonize the distal bowel during early pregnancy. Genetic defects underlie HSCR, but much of the variability in the occurrence and severity of the birth defect remain unexplained. We hypothesized that nongenetic factors might contribute to disease development. Here we found that mycophenolate, an inhibitor of de novo guanine nucleotide biosynthesis, and 8 other drugs identified in a zebrafish screen impaired ENS development. In mice, mycophenolate treatment selectively impaired ENS precursor proliferation, delayed precursor migration, and induced bowel aganglionosis. In 2 different mouse models of HSCR, addition of mycophenolate increased the penetrance and severity of Hirschsprung-like pathology. Mycophenolate treatment also reduced ENS precursor migration as well as lamellipodia formation, proliferation, and survival in cultured enteric neural crest-derived cells. Using X-inactivation mosaicism for the purine salvage gene Hprt, we found that reduced ENS precursor proliferation most likely causes mycophenolate-induced migration defects and aganglionosis. To the best of our knowledge, mycophenolate is the first medicine identified that causes major ENS malformations and Hirschsprung-like pathology in a mammalian model. These studies demonstrate a critical role for de novo guanine nucleotide biosynthesis in ENS development and suggest that some cases of HSCR may be preventable.

Hirschsprung Disease (HSCR) is a potentially deadly birth defect characterized by the absence of the enteric nervous system (ENS) in distal bowel. Although HSCR has clear genetic causes, no HSCR-associated mutation is 100% penetrant, suggesting gene-gene and gene-environment interactions determine HSCR occurrence. To test the hypothesis that certain medicines might alter HSCR risk we treated zebrafish with medications commonly used during early human pregnancy and discovered that ibuprofen caused HSCR-like absence of enteric neurons in distal bowel. Using fetal CF-1 mouse gut slice cultures, we found that ibuprofen treated enteric neural crest-derived cells (ENCDC) had reduced migration, fewer lamellipodia and lower levels of active RAC1/CDC42. Additionally, inhibiting ROCK, a RHOA effector and known RAC1 antagonist, reversed ibuprofen effects on migrating mouse ENCDC in culture. Ibuprofen also inhibited colonization of Ret+/− mouse bowel by ENCDC in vivo and dramatically reduced bowel colonization by chick ENCDC in culture. Interestingly, ibuprofen did not affect ENCDC migration until after at least three hours of exposure. Furthermore, mice deficient in Ptgs1 (COX 1) and Ptgs2 (COX 2) had normal bowel colonization by ENCDC and normal ENCDC migration in vitro suggesting COX-independent effects. Consistent with selective and strain specific effects on ENCDC, ibuprofen did not affect migration of gut mesenchymal cells, NIH3T3, or WT C57BL/6 ENCDC, and did not affect dorsal root ganglion cell precursor migration in zebrafish. Thus, ibuprofen inhibits ENCDC migration in vitro and bowel colonization by ENCDC in vivo in zebrafish, mouse and chick, but there are cell type and strain specific responses. These data raise concern that ibuprofen may increase Hirschsprung disease risk in some genetically susceptible children.

Uterine myomas are the most common type of benign tumor in women of reproductive age and are commonly associated with menorrhagia, dysmenorrhea, dyspareunia, and urinary symptoms. Uterine fibroids have been also linked to infertility and pregnancy loss. Women wishing to preserve or restore their fertility are best treated by myomectomy. Robotic-assisted laparoscopic myomectomy is one of the latest technological applications of minimally invasive surgery. Limited data exist regarding the feasibility of robotic-assisted laparoscopic myomectomy (RALM) in terms of pregnancy and surgical outcomes, and more studies are needed. The goal of this study is to assess reproductive outcomes following RALM in a private practice setting. The study was performed in the form of a retrospective chart review. Female patients 22-44 years old diagnosed with intramural myoma were eligible for inclusion. Presence of a myoma was a necessary but not necessarily the presenting symptom. All patients underwent RALM between January 2006 and May 2009 under the care of one surgeon at two clinical sites. Patients were selected postsurgically via chart review based on inclusion parameters outlined above. Median values for pregnancy rate, number of myomas, diameter of largest myoma, surgery duration, and blood loss were calculated and used for subsequent statistical analysis. Clinically useful markers for pregnancy outcomes evaluation following RALM were identified. Thirty patients were enrolled, of whom 16 were interested in conception due to infertility. A pregnancy rate of 75 % was recorded. Among those who conceived, eight patients (67 %) reported natural conception within 6 months of unprotected intercourse, while four patients (33 %) utilized assisted reproductive technologies to conceive. One patient (8 %) miscarried. Two patients (17 %) experienced premature delivery, at 28 and 32 weeks, respectively. All deliveries were performed via Cesarean section. No surgical complications were reported following RALM. There were no cases of scar dehiscence or rupture. The median number of myomas in those who delivered was estimated at 1.0 compared with 3.5 in those unable to conceive (p < 0.05). In addition, median age was 34 compared with 42.5 years, respectively (p < 0.05). This retrospective study assessed pregnancy outcomes following RALM. Our pregnancy rate of 75 % combined with a low incidence of complications contributes to the limited pool of data available on this topic, and supports the need for a multicenter trial to further evaluate effectiveness and safety of RALM in terms of pregnancy outcomes.

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