Retroperitoneal Fibrosis: Role of Imaging in Diagnosis and Follow-Up.
Retroperitoneal Fibrosis: Role of Imaging in Diagnosis and Follow-up.
Radiographics. 2013 Mar; 33(2): 535-52
Caiafa RO, Vinuesa AS, Izquierdo RS, Brufau BP, Ayuso Colella JR, Molina CN
Retroperitoneal fibrosis (RPF) encompasses a range of diseases characterized by proliferation of aberrant fibroinflammatory tissue, which usually surrounds the infrarenal portion of the abdominal aorta, inferior vena cava, and iliac vessels. This process may extend to neighboring structures, frequently entrapping and obstructing the ureters and eventually leading to renal failure. The idiopathic form of RPF accounts for more than two-thirds of cases; the rest are secondary to factors such as drug use, malignancies, or infections. If promptly diagnosed and treated, idiopathic and most other benign forms of RPF have a good prognosis. In contrast, malignant RPF, which accounts for up to 10% of cases, has a poor prognosis. Therefore, the most important diagnostic challenge is differentiation of benign from malignant RPF. Imaging plays a key role in diagnosis of RPF. Cross-sectional imaging studies, particularly multidetector computed tomography (CT) and magnetic resonance (MR) imaging, are considered the imaging modalities of choice. Imaging features may help distinguish between benign and malignant RPF, but in some cases histopathologic examination of the retroperitoneal tissue is needed for definitive diagnosis. CT and MR imaging, along with positron emission tomography with fluorine 18 fluorodeoxyglucose, also play an important role in management and follow-up of idiopathic RPF. © RSNA, 2013. HubMed – drug
A decade of the Common Drug Review.
CMAJ. 2013 Mar 11;
Spitz S
Polar transmembrane interactions drive formation of ligand-specific and signal pathway-biased family B G protein-coupled receptor conformations.
Proc Natl Acad Sci U S A. 2013 Mar 11;
Wootten D, Simms J, Miller LJ, Christopoulos A, Sexton PM
Recently, the concept of ligand-directed signaling-the ability of different ligands of an individual receptor to promote distinct patterns of cellular response-has gained much traction in the field of drug discovery, with the potential to sculpt biological response to favor therapeutically beneficial signaling pathways over those leading to harmful effects. However, there is limited understanding of the mechanistic basis underlying biased signaling. The glucagon-like peptide-1 receptor is a major target for treatment of type-2 diabetes and is subject to ligand-directed signaling. Here, we demonstrate the importance of polar transmembrane residues conserved within family B G protein-coupled receptors, not only for protein folding and expression, but also in controlling activation transition, ligand-biased, and pathway-biased signaling. Distinct clusters of polar residues were important for receptor activation and signal preference, globally changing the profile of receptor response to distinct peptide ligands, including endogenous ligands glucagon-like peptide-1, oxyntomodulin, and the clinically used mimetic exendin-4. HubMed – drug