Masses and masslike lesions of the pancreas are uncommon in the pediatric population. However, owing to overlapping clinical and imaging features, it can be challenging to differentiate the various causes of pediatric pancreatic masses at initial patient presentation. Clinical data such as patient age, signs and symptoms at presentation, laboratory test results, and potential underlying cancer predisposition syndrome can be helpful when formulating a differential diagnosis. US may be the first imaging study to depict a pancreatic mass in a child, as this examination is frequently performed in children with nonspecific abdominal signs and symptoms because of its wide availability and relatively low cost and the lack of a need for sedation or anesthesia. CT or MRI is typically required for more thorough characterization of the mass and surgical planning. Complete characterization of pancreatic masses includes assessment of vascular involvement, local invasion, and extrapancreatic spread of tumor. The authors provide an up-to-date comprehensive review of the clinical manifestations, histopathologic features, and imaging findings of primary and secondary tumors of the pancreas in children and young adults. Advances in imaging, current prognostic information, and treatment paradigms also are highlighted. Finally, nontumorous masslike lesions of the pediatric pancreas, including vascular malformations, cystic disorders (eg, von Hippel-Lindau syndrome, cystic fibrosis), intrapancreatic accessory spleen, and autoimmune pancreatitis, are discussed.
We report the reactions of several heteroallenes (carbon disulfide, carbonyl sulfide, and phenyl isocyanate) and carbon monoxide with a three-coordinate, bis(phosphine)-supported Rh(I) disilylamide (1). Carbon disulfide reacts with 1 to afford a silyltrithiocarbonate complex similar to an intermediate previously invoked in the deoxygenation of CO2 by 1, and prolonged heating affords a structurally unusual μ-κ(2)(S,S'):κ(2)(S,S')-trithiocarbonate dimer. Carbonyl sulfide reacts with 1 to afford a structurally unique Rh(SCNCS) metallacycle derived from two insertions of OCS and N-to-O silyl-group migrations. Phenyl isocyanate reacts with 1 to afford a dimeric bis(phenylcyanamido)-bridged complex resulting from multiple silyl-group migrations and nitrogen-for-oxygen metathesis, akin to reactivity previously observed with carbon dioxide. The ability of 1 to activate carbon-chalcogen multiple bonds via silyl-group migration is further supported by its reactivity with carbon monoxide, where a nitrogen-for-oxygen metathesis is also observed with expulsion of hexamethyldisiloxane. For all reported reactions, intermediates are observable under appropriate conditions, allowing the formulation of mechanisms where insertion of the unsaturated substrate is followed by one or more silyl-group migrations to afford the observed products. This rich variety of reactivity confirms the ability of metal silylamides to activate exceptionally strong carbon-element multiple bonds and suggests that silylamides may be useful intermediates in nitrogen-atom and nitrene-group-transfer schemes.
Clinically significant endemic mycoses (fungal infections) in the United States (U.S.) include Blastomyces dermatitidis, Histoplasma capsulatum, and Coccidioides immitis/posadasii. While the majority of infections go clinically unnoticed, symptomatic disease can occur in immunocompromised or hospitalized patients, and occasionally in immune-competent individuals. Clinical manifestations vary widely and their diagnosis may require fungal culture, making the rapid diagnosis a challenge. Imaging can be helpful in making a clinical diagnosis prior to laboratory confirmation, as well as assist in characterizing disease extent and severity. In this review, we discuss the three major endemic fungal infections that occur in the U.S., including mycology, epidemiology, clinical presentations, and typical imaging features with an emphasis on the pediatric population.
Current models governing how boards of medicine regulate the practice of medicine rely heavily on concepts from the past. Changes in our understanding of how medical errors occur, as well as in the organization and delivery of health care, have created challenges for boards when addressing medical errors. We conducted a qualitative study to explore the principles that boards use to respond to medical errors and to identify opportunities for improvement. Twenty key informant interviews were conducted with board members and staff, followed by two focus group discussions with 16 participants who actively participate in the process of medical regulation. Our results show that the major principles guiding boards of medicine in regulation around medical errors include fairness, consistency, efficiency and transparency. Implementation of these principles proved difficult, partly because of boards’ lack of authority over health care institutions. We recommend the development of a broader array of tools for boards to use in response to medical errors. Increased efforts are also needed to strengthen communication and collaboration among boards, physicians and health care organizations. Additionally, we suggest that boards implement and report performance metrics to promote public engagement and enhance trust in them.
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