Shoulder Dystocia and Neonatal Resuscitation: An Integrated Obstetrics and Neonatology Simulation Case for Medical Students.

INTRODUCTION: The new model in medical education of longitudinal clinical clerkships can be complemented by high-technology simulation, which provides a safe space for learners to consolidate clinical knowledge and practice decision-making skills, teamwork, and communication. We developed an interdisciplinary training intervention including a simulation case and structured debriefing to link clinical content between pediatrics and obstetrics at a major academic medical center. METHODS: In this case, a 38-year-old female at 38 weeks gestation presents with onset of labor complicated by shoulder dystocia. After the appropriate maneuvers, a depressed neonate is delivered and requires resuscitation. Major equipment needed includes a high- or low-technology birthing mannequin and an infant mannequin. RESULTS: Fifty-four third-year medical students participated in this simulation-based intervention at the completion of their integrated pediatrics and obstetrics clerkship. Ninety-one percent of students agreed that the shoulder dystocia simulation was designed appropriately for their learning level and enhanced their ability to handle a risky delivery. Ninety-four percent agreed that the neonatal resuscitation simulation was designed appropriately for their learning level, and 89% reported an enhanced ability to handle a similar situation in the clinic following the intervention. The average overall ratings were 4.24 (SD = 0.61) and 4.06 (SD = 0.89) on a 5-point scale (1 = poor, 5 = excellent) for the obstetrics and pediatrics simulations, respectively. DISCUSSION: The integrated obstetrics and pediatrics scenario is feasible to run and clinically accurate. Two distinct areas of medicine in the third-year curriculum are logically incorporated into one cohesive simulation-based training intervention that students found positive and realistic.

Human adipose tissue expansion in pregnancy is impaired in gestational diabetes mellitus.

AIMS/HYPOTHESIS: During pregnancy, adipose tissue (AT) must expand to support the growing fetus and the future nutritional needs of the offspring. Limited expandability of AT is associated with insulin resistance, attributed to ectopic lipid deposition. This study aimed to investigate human AT expandability during pregnancy and its role in the pathogenesis of gestational diabetes mellitus (GDM). METHODS: This cross-sectional study of omental (OM) and subcutaneous (SQ) AT collected at Caesarean delivery included 11 pregnant and three non-pregnant women with normal glucose tolerance (NGT), five with GDM, three with type 2 diabetes mellitus. Adipocyte size, capillary density, collagen content and capillary growth were measured. Affymetrix arrays and real-time PCR studies of gene expression were performed. RESULTS: Mean OM adipocyte size was greater in women with GDM than in those with NGT (p = 0.004). Mean OM and SQ capillary density was lower in GDM compared with NGT (p = 0.015). Capillary growth did not differ significantly between groups. The most differentially expressed AT transcript when comparing non-pregnant and pregnant women corresponded to the IGF binding protein (IGFBP)-5, the expression levels of which was found by subsequent quantitative real-time PCR to be lower in women with GDM vs women with NGT (p < 0.0001). CONCLUSIONS/INTERPRETATION: The relative OM adipocyte hypertrophy and decreased OM and SQ capillary density are consistent with impaired AT expandability in GDM. The induction of adipose tissue IGFBP5 in pregnancy and its decrease in GDM point to the importance of the IGF-1 signalling pathway in AT expansion in pregnancy and GDM susceptibility.

A role for uric acid and the Nalp3 inflammasome in antiphospholipid antibody-induced IL-1ß production by human first trimester trophoblast.

Women with antiphospholipid syndrome (APS) are at risk of recurrent pregnancy loss and obstetrical disorders, such as preeclampsia and intrauterine growth restriction (IUGR). Antiphospholipid antibodies (aPL) directly target the placenta by binding beta2-glycoprotein I (ß2GPI) expressed on the trophoblast. We recently demonstrated in human first trimester trophoblast cells that anti-ß2GPI antibodies (Abs) induce the secretion of IL-1ß in a Toll-like receptor 4 (TLR4)-dependent manner. IL-1ß secretion requires processing of pro-IL-1ß and this is mediated by the inflammasome, a complex of Nalp3, apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1. The objective of this study was to determine if aPL induce IL-1ß production in trophoblast via the inflammasome. Using a human first trimester trophoblast cell line, we demonstrated that a mouse anti-ß2GPI mAb and human polyclonal aPL-IgG induce IL-1ß processing and secretion, which was partially blocked upon caspase-1 inhibition. Nalp3 and ASC knockdown also attenuated anti-ß2GPI Ab-induced IL-1ß secretion. Furthermore, aPL stimulated the production of uric acid in a TLR4-dependent manner; and inhibition of uric acid prevented aPL-induced IL-1ß production by the trophoblast. These findings demonstrate that aPL, via TLR4 activation, induce a uric acid response in human trophoblast, which in turn activates the Nalp3/ASC inflammasome leading to IL-1ß processing and secretion. This novel mechanism may account for the inflammation at the maternal-fetal interface, which causes placental dysfunction and increases the risk of adverse pregnancy outcome in patients with APS.

Heat-shock-mediated conditional regulation of hedgehog/gli signaling in zebrafish.

BACKGROUND: Hedgehog (Hh) signaling is required for embryogenesis and continues to play key roles postembryonically in many tissues, influencing growth, stem cell proliferation, and tumorigenesis. Systems for conditional regulation of Hh signaling facilitate the study of these postembryonic Hh functions. RESULTS: We used the hsp70l promoter to generated three heat-shock-inducible transgenic lines that activate Hh signaling and one line that represses Hh signaling. Heat-shock activation of these transgenes appropriately recapitulates early embryonic loss or gain of Hh function phenotypes. Hh signaling remains activated 24 hr after heat shock in the Tg(hsp70l:shha-EGFP) and Tg(hsp70l:dnPKA-BGFP) lines, while a single heat shock of the Tg(hsp70l:gli1-EGFP) or Tg(hsp70l:gli2aDR-EGFP) lines results in a 6- to 12-hr pulse of Hh signal activation or inactivation, respectively. Using both in situ hybridization and quantitative polymerase chain reaction, we show that these lines can be used to manipulate Hh signaling through larval and juvenile stages. A ptch2 promoter element was used to generate new reporter lines that allow clear visualization of Hh responding cells throughout the life cycle, including graded Hh responses in the embryonic central nervous system. CONCLUSIONS: These zebrafish transgenic lines provide important new experimental tools to study the embryonic and postembryonic roles of Hh signaling.

Uric acid induces trophoblast IL-1ß production via the inflammasome: implications for the pathogenesis of preeclampsia.

PROBLEM: Preeclampsia is associated with hyperuricemia, which correlates with the disease severity. Levels of circulating uric acid increase before the clinical manifestations, suggesting that they may be causally related. Uric acid, or monosodium urate (MSU), activates the Nod-like receptor, Nalp3, leading to inflammasome activation and IL-1ß processing. Because preeclampsia is associated with placental immune/ inflammatory dysregulation, we sought to determine in the trophoblast, the presence of the Nalp3 inflammasome, and the effect of MSU on its activation. METHOD OF STUDY: Isolated first- and third-trimester trophoblasts were assessed for expression of the inflammasome components, Nalp1, Nalp3, and ASC. First-trimester trophoblast cells were incubated with or without MSU, and after which, IL-1ß secretion and processing and caspase-1 activation were determined. RESULTS: Trophoblast cells expressed Nalp1, Nalp3, and ASC under basal conditions. Following incubation with MSU, first-trimester trophoblast IL-1ß secretion was upregulated. This correlated with increased expression levels of active IL-1ß and active caspase-1. ASC knockdown reduced MSU-induced IL-1ß secretion. CONCLUSION: These findings demonstrate that uric acid activates the inflammasome in the trophoblast, leading to IL-1ß production. This may provide a novel mechanism for the induction of inflammation at the maternal­fetal interface leading to placental dysfunction and adverse pregnancy outcome, including preeclampsia.