ABSTRACT
Global surgery is an emerging academic discipline that is developing in tandem with numerous policy and advocacy initiatives. In this regard, academic global surgery will be crucial for measuring the progress toward improving surgical care worldwide. However, as a nascent academic discipline, there must be rigorous standards for the quality of work that emerges from this field. In this white paper, which reflects the opinion of the Global Academic Surgery Committee of the Society for University Surgeons, we discuss the importance of research in global surgery, the methodologies that can be used in such research, and the challenges and benefits associated with carrying out this research. In each of these topics, we draw on existing examples from the literature to demonstrate our points. We conclude with a call for continued, high-quality research that will strengthen the discipline's academic standing and help us move toward improved access to and quality of surgical care worldwide.
Subject(s)
General Surgery/organization & administration , Internationality , Research/standardsABSTRACT
Obesity is a multi-organ system disease with underlying metabolic abnormalities and chronic systemic inflammation. Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of obesity metabolic dysfunction and its associated cardiovascular- and liver-related morbidities and mortality. Our current understanding of NAFLD pathogenesis, disease characteristics, the role of insulin resistance, chronic inflammation, gut-liver and gut-brain crosstalk and the effectiveness of pharmacotherapy is still evolving. Bariatric surgery significantly improves metabolic and NAFLD histology in severely obese patients, although its positive effects on fibrosis are not universal. Bariatric surgery benefits NAFLD through its metabolic effect on insulin resistance, inflammation, and insulinotropic and anorexinogenic gastrointestinal hormones. Further studies are needed to understand the natural course of NAFLD in severely obese patients and the role of weight loss surgery as a primary treatment for NAFLD.
ABSTRACT
Pancreatic ductal adenocarcinoma (PDAC) is almost always lethal. One of the underlying reasons for this lethality is believed to be the presence of cancer stem cells (CSC), which impart chemoresistance and promote recurrence, but the mechanisms responsible are unclear. Recently the poor prognosis of PDAC has been correlated with increased expression of urokinase plasminogen activator (uPA). In the present study we examine the role of uPA in the generation of PDAC CSC. We observe a subset of cells identifiable as a side population (SP) when sorted by flow cytometry of MIA PaCa-2 and PANC-1 pancreatic cancer cells that possess the properties of CSC. A large fraction of these SP cells are CD44 and CD24 positive, are gemcitabine resistant, possess sphere-forming ability, and exhibit increased tumorigenicity, known characteristics of cancer stemness. Increased tumorigenicity and gemcitabine resistance decrease after suppression of uPA. We observe that uPA interacts directly with transcription factors LIM homeobox-2 (Lhx2), homeobox transcription factor A5 (HOXA5), and Hey to possibly promote cancer stemness. uPA regulates Lhx2 expression by suppressing expression of miR-124 and p53 expression by repressing its promoter by inactivating HOXA5. These results demonstrate that regulation of gene transcription by uPA contributes to cancer stemness and clinical lethality.
