Surgical robotics instructors provide an essential service in improving the competency of novice gynecologic surgeons learning robotic surgery and advancing surgical skills on behalf of patients. However, despite best intentions, robotics instructors and the gynecologists who use their services expose themselves to liability. The fear of litigation in the event of a surgical complication may reduce the availability and utility of robotics instructors. A better understanding of the principles of duty of care and the physician-patient relationship, and their potential applicability in a court of law likely will help to dismantle some concerns and uncertainties about liability. This commentary is not meant to discourage current and future surgical instructors but to raise awareness of liability issues among robotics instructors and their students and to recommend certain preventive measures to curb potential liability risks.

BACKGROUND & AIMS: The exocrine portion of the pancreas functions in digestion and preserves pancreatic homeostasis. Learning how this tissue forms during embryogenesis could improve our understanding of human pancreatic diseases. Expression of the homeobox gene Prox1 in the exocrine pancreas changes throughout development in mice. We investigated the role of Prox1 in development of the exocrine pancreas in mice. METHODS: Mice with pancreas-specific deletion of Prox1 (Prox1ΔPanc) were generated and their pancreatic tissues were analyzed using immunohistochemistry, transmission-electron microscopy, histologic techniques, quantitative real-time PCR, immunoblotting, and morphometric analysis. RESULTS: Loss of Prox1 from the pancreas led to multiple exocrine alterations, most notably premature acinar cell differentiation, increased ductal cell proliferation, altered duct morphogenesis, and imbalanced expression of claudin proteins. Prox1ΔPanc mice also had some minor alterations in islet cells, but β-cell development was not affected. The exocrine congenital defects of Prox1ΔPanc pancreata appeared to initiate a gradual process of deterioration that resulted in extensive loss of acinar cells, lipomatosis, and damage to ductal tissue in adult mice. CONCLUSIONS: Pancreas-specific deletion of Prox1 causes premature differentiation of acinar cells and poor elongation of epithelial branches; these defects indicate that Prox1 controls the expansion of tip progenitors in the early developing pancreas. During later stages of embryogenesis, Prox1 appears to regulate duct cell proliferation and morphogenesis. These findings identify Prox1 as an important regulator of pancreatic exocrine development.

BACKGROUND: Neoplasms of the pancreas during pregnancy are rare, with less than 25 cases of benign and malignant tumors reported in the literature. METHODS: We present three unique cases of pancreatic tumors occurring during pregnancy-one mucinous cystic neoplasm and two adenocarcinomas. We review the literature regarding pancreatic neoplasms during pregnancy and discuss the diagnosis, complications, and management of these tumors. RESULTS: Magnetic resonance imaging and ultrasound are the imaging modalities of choice in pregnancy. In patients with benign or premalignant tumors, surgical resection may be postponed until the second trimester. In symptomatic patients, or if there is a concern for intrauterine growth restriction, urgent surgical intervention should be performed. With malignant tumors, the benefit of delaying surgery must be balanced with the risk of maternal disease progression. Termination of the pregnancy should be discussed when a malignant tumor is diagnosed during the first trimester. Pancreatic tumors diagnosed during the third trimester may be resected after delivery. If malignant, early delivery of the fetus and subsequent maternal operation can be considered at appropriate fetal maturity. CONCLUSION: When these tumors occur during pregnancy, they present a diagnostic and treatment dilemma, with variation in treatment based on gestational age and patient preference.

Extracellular ATP regulates many important cellular functions in the liver by stimulating purinergic receptors. Recent studies have shown that rapid exocytosis of ATP-enriched vesicles contributes to ATP release from liver cells. However, this rapid ATP release is transient, and ceases in ~30 s after the exposure to hypotonic solution. The purpose of these studies was to assess the role of vesicular exocytosis in sustained ATP release. An exposure to hypotonic solution evoked sustained ATP release that persisted for more than 15 min after the exposure. Using FM1-43 (N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl)pyridinium dibromide) fluorescence to measure exocytosis, we found that hypotonic solution stimulated a transient increase in FM1-43 fluorescence that lasted ~2 min. Notably, the rate of FM1-43 fluorescence and the magnitude of ATP release were not correlated, indicating that vesicular exocytosis may not mediate sustained ATP release from liver cells. Interestingly, mefloquine potently inhibited sustained ATP release, but did not inhibit an increase in FM1-43 fluorescence evoked by hypotonic solution. Consistent with these findings, when exocytosis of ATP-enriched vesicles was specifically stimulated by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), mefloquine failed to inhibit ATP release evoked by NPPB. Thus, mefloquine can pharmacologically dissociate sustained ATP release and vesicular exocytosis. These results suggest that a distinct mefloquine-sensitive membrane ATP transport may contribute to sustained ATP release from liver cells. This novel mechanism of membrane ATP transport may play an important role in the regulation of purinergic signaling in liver cells.

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Purinergic P2Y(2) G-protein coupled receptors play a key role in the regulation of hepatic Ca(2+) signaling by extracellular ATP. The concentration of copper in serum is about 20muM. Since copper accumulates in the liver in certain disease states, the purpose of these studies was to assess the effects of copper on P2Y(2) receptors in a model liver cell line. Exposure to a P2Y(2) agonist UTP increased [Ca(2+)](i) by stimulating Ca(2+) release from thapsigargin-sensitive Ca(2+) stores. Pretreatment of HTC cells for several minutes with copper did not affect cell viability, but potently inhibited increases in [Ca(2+)](i) evoked by UTP and thapsigargin. During this pretreatment, copper was not transported into the cytosol, and inhibited P2Y(2) receptors in a concentration-dependent manner with the IC(50) of about 15muM. These results suggest that copper inhibits P2Y(2) receptors through the effects on thapsigargin-sensitive Ca(2+) stores by acting from an extracellular side. Further experiments indicated that these effect of copper may lead to inhibition of regulatory volume decrease (RVD) evoked by hypotonic solution. Thus, copper may contribute to defective regulation of purinergic signaling and liver cell volume in diseases associated with the increased serum copper concentration.

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We examined whether the GRIK3 (T928G) polymorphic variants in patients with schizophrenia are different from those of their first-degree relatives and healthy controls. The study population was composed of 256 patients with schizophrenia, 305 first-degree relatives of schizophrenia patients and 242 healthy control subjects. The GRIK3 (T928G) polymorphism was determined by restriction fragment length polymorphism. The frequency of the TT genotype was predominant, whereas the GG genotype was rare among all groups. The frequencies of GRIK3 (T928G) genotype distributions in the patients with schizophrenia were similar to those of their relatives. The frequency of the GG genotype was significantly higher in patients than in healthy controls. Similarly, GG genotype distribution in relatives was elevated compared with that in controls, but this value did not reach statistical significance. On the other hand, the subgroups of schizophrenia patients did not show a significant association with the GRIK3 (T928G) gene. It appears that the patients share the same (GRIK3) T928G gene variants with their relatives. One interpretation of our findings is that the relatives are at risk for the development of schizophrenia in the future.