Management of patients with Graves' disease and orbital involvement: role of spectral domain optical coherence tomography

PURPOSE: To investigate the role of choroidal thickness evaluation with spectral domain optical coherence tomography (SDOCT) and enhanced depth imaging (EDI) technique in the management of patients with Graves' disease and orbitopathy (GO). METHODS: Thirty-six eyes of 18 patients with GO and 36 eyes of 18 age-matched control subjects were included in this retrospective observational study. All the subjects underwent a complete ophthalmological evaluation, including clinical activity score (CAS) and exophthalmometry. The SDOCT images of the choroid were obtained by EDI modality. RESULTS: Choroidal thickness was significantly increased in GO than in control eyes (p < 0.01). A significant correlation was found between choroidal thickness and CAS, proptosis, and the duration of disease (p < 0.05). CONCLUSION: This study shows that choroidal thickness, evaluated with EDI-OCT, is significantly increased in patients with GO and correlates with the activity of the disease, proptosis, and duration of the disease. The choroidal thickening may reflect the ocular hemodynamic changes, and enhanced depth imaging optical coherence tomography may be a useful tool for the evaluation of orbital congestion and management of patients with Graves' disease and orbital involvement

Experimental characterization of the interaction between the n-terminal sh3 domain of crkl and c3g

Crkl is a protein involved in the onset of several cancer pathologies that exerts its function only through its protein–protein interaction domains, a SH2 domain and two SH3 domains. SH3 domains are small protein interaction modules that mediate the binding and recognition of proline-rich sequences. One of the main physiological interactors of Crkl is C3G (also known as RAPGEF1), an interaction with key implications in regulating cellular growth and differentiation, cell morphogenesis and adhesion processes. Thus, understanding the interaction between Crkl and C3G is fundamental to gaining information about the molecular determinants of the several cancer pathologies in which these proteins are involved. In this paper, through a combination of fast kinetics at different experimental conditions and site-directed mutagenesis, we characterize the binding reaction between the N-SH3 domain of Crkl and a peptide mimicking a specific portion of C3G. Our results show a clear effect of pH on the stability of the complex, due to the protonation of negatively charged residues in the binding pocket of N-SH3. Our results are discussed under the light of previous work on SH3 domains

Unveiling induced folding of intrinsically disordered proteins – Protein engineering, frustration and emerging themes

Intrinsically disordered proteins (IDPs) can be generally described as a class of proteins that lack a well-defined ordered structure in isolation at physiological conditions. Upon binding to their physiological ligands, IDPs typically undergo a disorder-to-order transition, which may or may not lead to the complete folding of the IDP. In this short review, we focus on some of the key findings pertaining to the mechanisms of such induced folding. In particular, first we describe the general features of the reaction; then, we discuss some of the most remarkable findings obtained from applying protein engineering in synergy with kinetic studies to induced folding; and finally, we offer a critical view on some of the emerging themes when considering the structural heterogeneity of IDPs vis-à-vis to their inherent frustration

Determining folding and binding properties of the C-terminal SH2 domain of SHP2

SH2 domains are a class of protein–protein interaction modules with the function to recognize and bind sequences characterized by the presence of a phosphorylated tyrosine. SHP2 is a protein phosphatase involved in the Ras-ERK1/2 signaling pathway that possess two SH2 domains, namely, N-SH2 and C-SH2, that mediate the interaction of SHP2 with various partners and determine the regulation of its catalytic activity. One of the main interactors of the SH2 domains of SHP2 is Gab2, a scaffolding protein with critical role in determining cell differentiation. Despite their key biological role and the importance of a correct native fold to ensure it, the mechanism of binding of SH2 domains with their ligands and the determinants of their stability have been poorly characterized. In this article, we present a comprehensive kinetic study of the folding of the C-SH2 domain and the binding mechanism with a peptide mimicking a region of Gab2. Our data, obtained at different pH and ionic strength conditions and supported by site-directed mutagenesis, highlight the role of electrostatic interactions in the early events of recognition. Interestingly, our results suggest a key role of a highly conserved histidine residue among SH2 family in the interaction with negative charges carried by the phosphotyrosine of Gab2. Moreover, the analysis of the equilibrium and kinetic folding data of C-SH2 describes a complex mechanism implying a change in rate-limiting step at high denaturant concentrations. Our data are discussed under the light of previous works on N-SH2 domain of SHP2 and other SH2 domains

Traumatic brain injury and suicide risk

Among the various consequences of traumatic brain injury (TBI), evidence supports the notion that individuals exposed to such events may be at higher risk of suicide. We therefore aim at reviewing the literature by focusing on possible association between TBI and features of the suicidal spectrum, such as suicidal ideation, suicide attempts and completed suicides. We carried out a computerized search for reports of studies involving TBI and suicide risk. A total of 35 reports provide data with preliminary support of this association. Seven articles showed a direct correlation between TBI and completed suicides. Thirteen articles have shown a direct relationship between TBI and suicide attempts; five articles demonstrated a positive correlation with suicidal ideation and suicidality. We also found negative results failing to show a correlation between TBI and completed suicides (one article), suicide attempts (one article) and suicidality (one article). In addition, one article showed that patients who received psychological treatment (CBT therapy) after suffering a head injury showed a significant reduction in suicidal ideation. These preliminary findings encourage further testing of the association between TBI and suicide risk regardless of the psychiatric history. Furthermore, those who have a history of psychiatric illness before the TBI present a greater risk of suicide than those who do not have psychiatric precedents

On the Effects of Disordered Tails, Supertertiary Structure and Quinary Interactions on the Folding and Function of Protein Domains

The vast majority of our current knowledge about the biochemical and biophysical properties of proteins derives from in vitro studies conducted on isolated globular domains. However, a very large fraction of the proteins expressed in the eukaryotic cell are structurally more complex. In particular, the discovery that up to 40% of the eukaryotic proteins are intrinsically disordered, or possess intrinsically disordered regions, and are highly dynamic entities lacking a well-defined three-dimensional structure, revolutionized the structure–function paradigm and our understanding of proteins. Moreover, proteins are mostly characterized by the presence of multiple domains, in-fluencing each other by intramolecular interactions. Furthermore, proteins exert their function in a crowded intracellular milieu, transiently interacting with a myriad of other macromolecules. In this review we summarize the literature tackling these themes from both the theoretical and experimental perspectives, highlighting the effects on protein folding and function that are played by (i) flanking disordered tails; (ii) contiguous protein domains; (iii) interactions with the cellular environment, defined as quinary structures. We show that, in many cases, both the folding and function of protein domains is remarkably perturbed by the presence of these interactions, pinpointing the importance to increase the level of complexity of the experimental work and to extend the efforts to characterize protein domains in more complex contexts

Mini-extracorporeal circulation minimizes coagulation abnormalities and ameliorates pulmonary outcome in coronary artery bypass grafting surgery

Hemostasis is impaired during CABG and coagulation abnormalities often result in clinically relevant organ dysfunctions, eventually increasing morbidity and mortality rates. Fifteen consecutive patients with coronary artery disease submitted to conventional extracorporeal circulation (cECC) have been compared with 15 matched patients, using mini-ECC (MECC). Postoperative lung function was evaluated according to gas exchange, intubation time and lung injury score. In the MECC group, thrombin-antithrombin complex levels (TaTc), prothrombin fragments (PF1+2) formation and thromboelastography (TEG) clotting times were lower compared to the cECC group (p=0.002 and p<0.001, respectively) whereas postoperative blood loss was higher in the cECC group (p=0.030) and more patients required blood transfusion (p=0.020). In the MECC group, postoperative gas exchange values were better, intubation time shorter and lung injury score lower (p<0.001 for all comparisons). Our study suggests that MECC induces less coagulation disorders, leading to lower postoperative blood loss and better postoperative lung function. This approach may be advantageous in high-risk patients. © The Author(s) 2013

Targeting PDZ domains as potential treatment for viral infections, neurodegeneration and cancer

The interaction between proteins is a fundamental event for cellular life that is generally mediated by specialized protein domains or modules. PDZ domains are the largest class of protein–protein interaction modules, involved in several cellular pathways such as signal transduction, cell–cell junctions, cell polarity and adhesion, and protein trafficking. Because of that, dysregulation of PDZ domain function often causes the onset of pathologies, thus making this family of domains an interesting pharmaceutical target. In this review article we provide an overview of the structural and functional features of PDZ domains and their involvement in the cellular and molecular pathways at the basis of different human pathologies. We also discuss some of the strategies that have been developed with the final goal to hijack or inhibit the interaction of PDZ domains with their ligands. Because of the generally low binding selectivity of PDZ domain and the scarce efficiency of small molecules in inhibiting PDZ binding, this task resulted particularly difficult to pursue and still demands increasing experimental efforts in order to become completely feasible and successful in vivo

Correlación entre la hiperuricemia y la fructosamina como indicadores tempranos de desórdenes metabólicos en adultos jóvenes

Los desórdenes metabólicos como la diabetes mellitus, dislipemias, cardiopatías, etc. tienen gran incidencia en la población mundial. El ácido úrico (ACU) plasmático se relaciona con factores de riesgo cardiovascular, con la hipertensión y la diabetes mellitus. El ACU está considerado como un marcador de riesgo de enfermedad cardiovascular, cerebrovascular e infarto de miocardio, al comparar a pacientes y sujetos con concentraciones normales de ACU y en aquéllos en el tercio más bajo del intervalo fisiológico. La Fructosamina (FRU) es un metabolito con elevado valor pronóstico de la diabetes. La correlación de estos valores se asociaría en un diagnóstico precoz de enfermedades metabólicas en adultos jóvenes. Nuestro objetivo de investigación es determinar si la hiperuricemia es un posible marcador precoz de desórdenes metabólicos, basado en la correlación con valores de fructosamina en una población de adultos jóvenes de las provincias de Cuyo. Desde el año 2013 y hasta finales del año 2014 se estudiaron 1.060 postulantes a cubrir vacantes de Soldados Voluntarios de Mendoza y provincias vecinas