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Chen C.-C.,National Chiao Tung University | Er T.-K.,Kaohsiung Medical University | Liu Y.-Y.,National Chiao Tung University | Hwang J.-K.,National Chiao Tung University | And 3 more authors.
PLoS ONE | Year: 2013

Background: The issue of whether patients diagnosed with metastatic colorectal cancer who harbor KRAS codon 13 mutations could benefit from the addition of anti-epidermal growth factor receptor therapy remains under debate. The aim of the current study was to perform computational analysis to investigate the structural implications of the underlying mutations caused by c.38G>A (p.G13D) on protein conformation. Methods: Molecular dynamics (MD) simulations were performed to understand the plausible structural and dynamical implications caused by c.35G>A (p.G12D) and c.38G>A (p.G13D). The potential of mean force (PMF) simulations were carried out to determine the free energy profiles of the binding processes of GTP interacting with wild-type (WT) KRAS and its mutants (MT). Results: Using MD simulations, we observed that the root mean square deviation (RMSD) increased as a function of time for the MT c.35G>A (p.G12D) and MT c.38G>A (p.G13D) when compared with the WT. We also observed that the GTP-binding pocket in the c.35G>A (p.G12D) mutant is more open than that of the WT and the c.38G>A (p.G13D) proteins. Intriguingly, the analysis of atomic fluctuations and free energy profiles revealed that the mutation of c.35G>A (p.G12D) may induce additional fluctuations in the sensitive sites (P-loop, switch I and II regions). Such fluctuations may promote instability in these protein regions and hamper GTP binding. Conclusions: Taken together with the results obtained from MD and PMF simulations, the present findings implicate fluctuations at the sensitive sites (P-loop, switch I and II regions). Our findings revealed that KRAS mutations in codon 13 have similar behavior as KRAS WT. To gain a better insight into why patients with metastatic colorectal cancer (mCRC) and the KRAS c.38G>A (p.G13D) mutation appear to benefit from anti-EGFR therapy, the role of the KRAS c.38G>A (p.G13D) mutation in mCRC needs to be further investigated. © 2013 Chen et al. Source

Rivero-Lezcano O.M.,Fundacion Institute Estudios Of Ciencias Of La Salud Of Castilla Y Leon | Diez-Tascon C.,Servicio de Anatomia Patologica
Clinical and Experimental Immunology | Year: 2010

CCL20 is a chemokine that attracts immature dendritic cells. We show that monocytes, cells characteristic of the innate immune response, infected with Mycobacterium tuberculosis express the CCL20 gene at a much higher level than the same cells infected with non-tuberculous mycobacteria. Interferon (IFN)-γ, a fundamental cytokine in the immune response to tuberculosis, strongly inhibits both the transcription and the translation of CCL20. We have also confirmed that dendritic cells are a suitable host for mycobacteria proliferation, although CCL20 does not seem to influence their intracellular multiplication rate. The chemokine, however, down-regulates the characteristic production of reactive oxygen species (ROS) induced by M. tuberculosis in monocytes,whichmay affect the activity of the cells.Apoptosis mediated by the mycobacteria, possibly ROS-dependent, was also inhibited by CCL20. © 2010 The Authors Clinical and Experimental Immunology © 2010 British Society for Immunology. Source

Galvan J.A.,Instituto Universitario Of Oncologia Del Principado Of Asturias | Astudillo A.,Hospital Universitario Central Of Asturias | Vallina A.,Instituto Universitario Of Oncologia Del Principado Of Asturias | Fonseca P.J.,Hospital Universitario Central Of Asturias | And 3 more authors.
American Journal of Clinical Pathology | Year: 2013

Objectives: To elucidate the role of epithelial-mesenchymal transition markers in gastroenteropancreatic neuroendocrine tumors (GEP NETs) and the potential usefulness in their clinical management. Methods: One hundred ten GEP NET paraffinembedded samples were immunohistochemically analyzed for E-cadherin, N-cadherin, β-catenin, vimentin, Snail1, Snail2, Twist, and Foxc2 protein expression. Results: The 5-year survival rate was reduced for those patients showing high Snail1 protein levels, a cytoplasmic E-cadherin pattern, reduced N-cadherin expression, and loss of E-cadherin/β-catenin adhesion complex integrity at the cell membrane. Interestingly, high β-catenin expression was useful in identifying a grade 1 NET subgroup with a favorable clinical course. Importantly, it also helped to discriminate small-cell vs large-cell grade 3 neuroendocrine carcinomas. Conclusions: β-Catenin and N-cadherin immunohistochemical detection might be a useful tool in the differential diagnosis of small-cell vs large-cell G3 neuroendocrine carcinomas. High Snail1 and Foxc2 expression is associated with the invasion and metastatic spread of GEP NETs. © 2013 American Society for Clinical Pathology. Source

Fernandez-Flores A.,Servicio de Anatomia Patologica
American Journal of Dermatopathology | Year: 2015

In this article, we present a compendium of the most relevant histological features of the skin in terms of their regional variations along with histological clues that facilitate the topographic identification of cutaneous biopsies. Copyright © 2015 Wolters Kluwer Health, Inc. Source

Lorenzo V.,Hospital Universitario Of Canarias | Torres A.,Hospital Universitario Of Canarias | Salido E.,Servicio de Anatomia Patologica
Nefrologia | Year: 2014

Primary hyperoxaluria (PH) occurs due to an autosomal recessive hereditary disorder of the metabolism of glyoxylate, which causes excessive oxalate production. The most frequent and serious disorder is due to enzyme deficit of alanine-glyoxylate aminotransferase (PH type I) specific to hepatic peroxisome. As oxalate is not metabolised in humans and is excreted through the kidneys, the kidney is the first organ affected, causing recurrent lithiasis, nephrocalcinosis and early renal failure. With advance of renal failure, particularly in patients on haemodialysis (HD), calcium oxalate is massively deposited in tissues, which is known as oxalosis. Diagnosis is based on family history, the presence of urolithiasis and/or nephrocalcinosis, hyperoxaluria, oxalate deposits in tissue forming granulomas, molecular analysis of DNA and enzyme analysis if applicable. High diagnostic suspicion is required; therefore, unfortunately, in many cases it is diagnosed after its recurrence following kidney transplantation. Conservative management of this disease (high liquid intake, pyridoxine and crystallisation inhibitors) needs to be adopted early in order to delay kidney damage. Treatment by dialysis is ineffective in treating excess oxalate. After the kidney transplant, we normally observe a rapid appearance of oxalate deposits in the graft and the results of this technique are discouraging, with very few exceptions. Pre-emptive liver transplantation, or simultaneous liver and kidney transplants when there is already irreversible damage to the kidney, is the treatment of choice to treat the underlying disease and suppress oxalate overproduction. Given its condition as a rare disease and its genetic and clinical heterogeneity, it is not possible to gain evidence through randomised clinical trials. As a result, the recommendations are established by groups of experts based on publications of renowned scientific rigour. In this regard, a group of European experts (OxalEurope) has drawn up recommendations for diagnosis and treatment, which were published in 2012. © 2014 Revista Nefrología. Source

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