ESR Essentials: pseudolesions in head and neck-practice recommendations by the European Society of Head and Neck Radiology.

The differentiation between pathological and physiological entities constitutes a fundamental aspect of daily radiological practice. Pseudolesions manifest as a transient phenomenon within this spectrum, displaying features of pathology within the context of normal or variant anatomy. A variety of structures, including vascular components, ectopic formations, or deviations from typical developmental patterns, can mimic pathological entities.

Gαs slow conformational transition upon GTP binding and a novel Gαs regulator.

G proteins are major signaling partners for G protein-coupled receptors (GPCRs). Although stepwise structural changes during GPCR-G protein complex formation and guanosine diphosphate (GDP) release have been reported, no information is available with regard to guanosine triphosphate (GTP) binding. Here, we used a novel Bayesian integrative modeling framework that combines data from hydrogen-deuterium exchange mass spectrometry, tryptophan-induced fluorescence quenching, and metadynamics simulations to derive a kinetic model and atomic-level characterization of stepwise conformational changes incurred by the β-adrenergic receptor (βAR)-Gs complex after GDP release and GTP binding.

Pathological tumor volume as a simple quantitative predictive factor of survival in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is the eighth most common type of cancer in the world. Knowledge of prognostic factors of survival in OSCC is key. Several clinical and pathological prognostic factors have been investigated to develop a prognostic model of survival for patients with oral cancer.

Structure-Based Discovery of a Novel Class of Small-Molecule Pure Antagonists of Integrin αVβ3.

Inhibitors of integrin αVβ3 have therapeutic promise for a variety of diseases. Most αVβ3-targeting small molecules patterned after the RGD motif are partial agonists because they induce a high-affinity, ligand-binding conformation and prime the receptor to bind the ligand without an activating stimulus, in part a charge-charge interaction between their aspartic acid carboxyl group and the metal ion in the metal-ion-dependent adhesion site (MIDAS). Building upon our previous studies on the related integrin αIIbβ3, we searched for pure αVβ3 antagonists that lack this typical aspartic acid carboxyl group and instead engage through direct binding to one of the coordinating residues of the MIDAS metal ion, specifically β3 E220.

Metastasis of the Mucionous adenocarcinoma of breast to the mandibular gingiva: Rare case report.

Introduction: Mucinous adenocarcinoma (MAC) is a rare type of cancer in which more than 50% of the tumor is composed of extracellular mucin and malignant epithelial cells. MACs account for only 1.8% of all breast cancer cases.

Imaging of acute pelvic pain.

Acute pelvic pain (APP) requires urgent medical evaluation and treatment. Differential diagnosis of APP is broad, including a variety of gynecologic and non-gynecologic/ urinary, gastrointestinal, vascular and other entities. Close anatomical and physiological relations of pelvic structures, together with similar clinical presentation of different disorders and overlapping of symptoms, especially in the emergency background, make the proper diagnosis of APP challenging.

Cryo-Electron Microscopy Structure of the αIIbβ3-Abciximab Complex.

Objective: The αIIbβ3 antagonist antiplatelet drug abciximab is the chimeric antigen-binding fragment comprising the variable regions of murine monoclonal antibody 7E3 and the constant domains of human IgG1 and light chain κ. Previous mutagenesis studies suggested that abciximab binds to the β3 C177-C184 specificity-determining loop (SDL) and Trp129 on the adjacent β1-α1 helix. These studies could not, however, assess whether 7E3 or abciximab prevents fibrinogen binding by steric interference, disruption of either the αIIbβ3-binding pocket for fibrinogen or the β3 SDL (which is not part of the binding pocket but affects fibrinogen binding), or some combination of these effects.

Systematic radiological approach to utero-ovarian pathologies.

Ultrasound is the first-line imaging modality for the evaluation of suspected adnexal masses, endometriosis and uterine tumors, whereas MRI is used as a secondary diagnostic tool to better characterize these lesions. The aim of this review is to summarize the latest advances in the imaging of these utero-ovarian pathologies.

Chemically Accurate Relative Folding Stability of RNA Hairpins from Molecular Simulations.

To benchmark RNA force fields, we compared the folding stabilities of three 12-nucleotide hairpin stem loops estimated by simulation to stabilities determined by experiment. We used umbrella sampling and a reaction coordinate of end-to-end (5' to 3' hydroxyl oxygen) distance to estimate the free energy change of the transition from the native conformation to a fully extended conformation with no hydrogen bonds between non-neighboring bases. Each simulation was performed four times using the AMBER FF99+bsc0+χ force field, and each window, spaced at 1 Å intervals, was sampled for 1 μs, for a total of 552 μs of simulation.

Improving RNA nearest neighbor parameters for helices by going beyond the two-state model.

RNA folding free energy change nearest neighbor parameters are widely used to predict folding stabilities of secondary structures. They were determined by linear regression to datasets of optical melting experiments on small model systems. Traditionally, the optical melting experiments are analyzed assuming a two-state model, i.

Molecular dynamics correctly models the unusual major conformation of the GAGU RNA internal loop and with NMR reveals an unusual minor conformation.

The RNA "GAGU" duplex, (5'GACGUCA), contains the internal loop (5'-GAGU-3') , which has two conformations in solution as determined by NMR spectroscopy. The major conformation has a loop structure consisting of -Watson-Crick/Hoogsteen GG pairs, A residues stacked on each other, U residues bulged outside the helix, and all sugars with a C2'- conformation. This differs markedly from the internal loops, (5'-GC-3'), (5'-AU-3'), and (5'-UAGG-3'), which all have -Watson-Crick/Watson-Crick AG "imino" pairs flanked by -Watson-Crick/Watson-Crick canonical pairs resulting in maximal hydrogen bonding.

Modeling RNA secondary structure folding ensembles using SHAPE mapping data.

RNA secondary structure prediction is widely used for developing hypotheses about the structures of RNA sequences, and structure can provide insight about RNA function. The accuracy of structure prediction is known to be improved using experimental mapping data that provide information about the pairing status of single nucleotides, and these data can now be acquired for whole transcriptomes using high-throughput sequencing. Prior methods for using these experimental data focused on predicting structures for sequences assuming that they populate a single structure.

Revised RNA Dihedral Parameters for the Amber Force Field Improve RNA Molecular Dynamics.

The backbone dihedral parameters of the Amber RNA force field were improved by fitting using multiple linear regression to potential energies determined by quantum chemistry calculations. Five backbone and four glycosidic dihedral parameters were fit simultaneously to reproduce the potential energies determined by a high-level density functional theory calculation (B97D3 functional with the AUG-CC-PVTZ basis set). Umbrella sampling was used to determine conformational free energies along the dihedral angles, and these better agree with the population of conformations observed in the protein data bank for the new parameters than for the conventional parameters.

Metastasis of Prostate Adenocarcinoma to the Testis.

Introduction: Prostate carcinoma is the most frequently diagnosed carcinoma in the male population. The most typical places of the metastases are pelvic lymphatic glands, bones and lungs, and very rarely it metastasizes into a testis. The prognostic importance of testicular metastasis of prostate cancer is not yet well-known, due to a very few published cases.

Gigantic spermatocytic seminoma: A rare tumor of germ cell origin.

Introduction: Spermatocytic seminoma represents a rare hystologic type of malignant testicular germ cell tumor with slow course and low malignant potential.

Case Report: We presented a 69-year-old patient with atypical clinical presentation of spermatocytic seminoma initially diagnosed as gigantic hydrocoellae which compromised walking. After long term evolution clincal picture presented with signs and symptoms of acute scrotum.

An Aggressive Retroperitoneal Fibromatosis.

Introduction: Aggressive fibromatosis (AF) is a heterogeneous group of mesenchymal tumors that have locally infiltrative growth and a tendency to relapse. The clinical picture is often conditioned by the obstruction of the ureter or small intestine. Diagnosis is based on clinical, radiological and histological parameters.

The clinical course of non-muscle invasive bladder cancer after transurethral resection of the tumor with or without subsequent intravesical application of bacillus Calmette-Guérin: The influence of patients gender and age.

Unlabelled: BACGROUND/AIM: The therapy with intravesical instillation of bacillus Calmette-Guérin (BCG) after transurethral resection (TUR) of tumor is the gold standard of treatment of non-muscle invasive bladder cancer (NMIBC). The role and importance of BCG intravesical therapy in various shape of tumors, were confirmed by our previous investigation. The aim of this study was to examine whether incidence of recurrence and tumor regression differs depending on sex and age of patients.

Difference in recurrence frequencies of non-muscle-invasive-bladder tumors depending on optimal usage of intravesical immunotherapy of bacillus Calmette-Guérin.

Background/aim: The therapy with intravesical instillation of bacillus Calmette-Guérin (BCG) after transurethral resection (ITJR) of the tumor is the gold standard of treatment of non-muscle invasive bladder cancer (NMIBC). The aim of this study was to compare the frequencies of reccurence between a group of patients submitted to TUR + BCG therapy (group I) and a group of patients submitted only to TUR (group II).

Methods: The patients with NMIBC, a total of 899, treated in our Institution from January 1, 2007 to March, 2013, were included in this study and divided into two groups: group I and group II.

Radical cystectomy in eldery.

Background/aim: Radical cystectomy is the method of choice for the treatment of muscle invasive bladder cancer. This major surgery is associated with many complications, especially in older patients. The aim of this study was to analyze preoperative comorbidity, and intraoperative and postoperative complicatons in patients older than 75 years.

DNA Duplex Formation with a Coarse-Grained Model.

A middle-resolution coarse-grained model of DNA is proposed. The DNA chain is built of spherical and planar rigid bodies connected by elastic virtual bonds. The bonded part of the potential energy function is fit to potentials of mean force of model systems.

Scoring system development for prediction of extravesical bladder cancer.

Background/aim: Staging of bladder cancer is crucial for optimal management of the disease. However, clinical staging is not perfectly accurate. The aim of this study was to derive a simple scoring system in prediction of pathological advanced muscle-invasive bladder cancer (MIBC).

Modified Amber Force Field Correctly Models the Conformational Preference for Tandem GA pairs in RNA.

Molecular mechanics with all-atom models was used to understand the conformational preference of tandem guanine-adenine (GA) noncanonical pairs in RNA. These tandem GA pairs play important roles in determining stability, flexibility, and structural dynamics of RNA tertiary structures. Previous solution structures showed that these tandem GA pairs adopt either imino (cis Watson-Crick/Watson-Crick A-G) or sheared (trans Hoogsteen/sugar edge A-G) conformations depending on the sequence and orientation of the adjacent closing base pairs.