Mendoza C.S.,Polytechnic University of Valencia |
Acha B.,Polytechnic University of Valencia |
Serrano C.,Polytechnic University of Valencia |
Gomez-Cia T.,Hospitales Universitarios Virgen del Rocio
Machine Vision and Applications | Year: 2012
In this paper, we propose a self-assessed adaptive region growing segmentation algorithm. In the context of an experimental virtual-reality surgical planning software platform, our method successfully delineates main tissues relevant for reconstructive surgery, such as fat, muscle, and bone. We rely on a self-tuning approach to deal with a great variety of imaging conditions requiring limited user intervention (one seed). The detection of the optimal parameters is managed internally using a measure of the varying contrast of the growing region, and the stopping criterion is adapted to the noise level in the dataset thanks to the sampling strategy used for the assessment function. Sampling is referred to the statistics of a neighborhood around the seed(s), so that the sampling period becomes greater when images are noisier, resulting in the acquisition of a lower frequency version of the contrast function. Validation is provided for synthetic images, as well as real CT datasets. For the CT test images, validation is referred to manual delineations for 10 cases and to subjective assessment for another 35. High values of sensitivity and specificity, as well as Dice's coefficient and Jaccard's index on one hand, and satisfactory subjective evaluation on the other hand, prove the robustness of our contrast-based measure, even suggesting suitability for calibration of other region-based segmentation algorithms. © 2010 Springer-Verlag.
Aguilar Reina J.,Hospitales Universitarios Virgen del Rocio
Medicine (Spain) | Year: 2012
Hepatic encephalopathy is a neuropsychiatric complication of acute and chronic liver diseases with characteristics morphological changes in astrogial cells. Overt HE is a potencially reversible syndrome. Minimal hepatic encephalopathy is the mildest form of HE. Several scales facilitate monitoring and assessment of overt HE; neuropsychological and neurophysiological tests can establish the diagnosis of minimal HE. The general consensus is that these individuals are unable to remove toxic substances, especially ammonia, derived from the intestine. In patients with cirrhosis the accumulation of ammonia results mainly due to hepatocellular failure and portosystemic shunting. Current treatment is based on reduced intestinal ammonia load by antibiotics or disaccarides, nevertheless the actual efficacy of these treatment is to be thoroughly established.
Morris IV J.P.,University of California at San Francisco |
Cano D.A.,University of California at San Francisco |
Cano D.A.,Hospitales Universitarios Virgen del Rocio |
Sekine S.,University of California at San Francisco |
And 3 more authors.
Journal of Clinical Investigation | Year: 2010
Cellular plasticity in adult organs is involved in both regeneration and carcinogenesis. WT mouse acinar cells rapidly regenerate following injury that mimics acute pancreatitis, a process characterized by transient reactivation of pathways involved in embryonic pancreatic development. In contrast, such injury promotes the development of pancreatic ductal adenocarcinoma (PDA) precursor lesions in mice expressing a constitutively active form of the GTPase, Kras, in the exocrine pancreas. The molecular environment that mediates acinar regeneration versus the development of PDA precursor lesions is poorly understood. Here, we used genetically engineered mice to demonstrate that mutant Kras promotes acinar-to-ductal metaplasia (ADM) and pancreatic cancer precursor lesion formation by blocking acinar regeneration following acute pancreatitis. Our results indicate that β-catenin is required for efficient acinar regeneration. In addition, canonical β-catenin signaling, a pathway known to regulate embryonic acinar development, is activated following acute pancreatitis. This regeneration-associated activation of β-catenin signaling was not observed during the initiation of Kras-induced acinar-to-ductal reprogramming. Furthermore, stabilized β-catenin signaling antagonized the ability of Kras to reprogram acini into PDA preneoplastic precursors. Therefore, these results suggest that β-catenin signaling is a critical determinant of acinar plasticity and that it is inhibited during Kras-induced fate decisions that specify PDA precursors, highlighting the importance of temporal regulation of embryonic signaling pathways in the development of neoplastic cell fates.
Eslam M.,Hospital Universitario Of Valme |
Lopez-Cortes L.F.,Hospitales Universitarios Virgen del Rocio |
Romero-Gomez M.,Hospital Universitario Of Valme
Current Opinion in HIV and AIDS | Year: 2011
Purpose of review: Insulin resistance, HIV, antiviral drugs and hepatitis C virus (HCV) infection contribute to a complex interaction involving the metabolic syndrome. The objective of this review was to explore the meaning of insulin resistance in HIV-HCV-coinfected patients and how it may impact on sustained virological response (SVR) and disease progression. Recent findings: In the HIV/HCV coinfection setting, insulin resistance seems to be associated with a reduction in rapid virological response and SVR to pegylated interferon and ribavirin, both in naive and treatment experienced patients. A recent meta-analysis demonstrated insulin resistance impairs SVR rate with an odds ratio 0.47 (95% confidence interval 0.31-0.71). However, many confounding factors may promote contradictory results. Prevalence of insulin resistance depends on surrogate markers of insulin resistance and the threshold for defining impaired insulin sensitivity. For example, homeostasis model for the assessment of insulin resistance may be influenced by both methods of insulin measurement and interpretation. Insulin sensitizers, lifestyle changes and improvement in the use of protease inhibitors should be evaluated in the management of coinfected patients. Summary: Insulin resistance is common finding in patients with HIV/HCV coinfection, with wide clinical consequences including progression of hepatic fibrosis and reduction in the response to antiviral treatment. Our understanding of this relationship continues to improve. More prospective studies are required to improve future management. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.
Martinez-Maestre M.A.,Hospitales Universitarios Virgen del Rocio |
Gonzalez-Cejudo C.,Hospitales Universitarios Virgen del Rocio |
MacHuca G.,University of Seville |
Torrejon R.,Hospitales Universitarios Virgen del Rocio |
Castelo-Branco C.,University of Barcelona
Climacteric | Year: 2010
Background Osteoporosis and periodontitis are frequent disorders that affect aging populations. It has been hypothesized that both conditions may be related. Objective To determine whether dental osteoporosis is a local manifestation of systemic bone loss having similar etiology and risk factors, or whether it is an independent process depending primarily on factors that cause periodontitis. Methods A systematic review of clinical trials assessing the relationship between osteoporosis and periodontitis was carried out. An electronic search was made based on Internet search engines, MEDLINE (from 1966 to December 2009) and the Cochrane Controlled Clinical Trials Register. Results A total of 145 studies dealing with the relationship osteoporosisperiodontitis were identified. Of them, 35 were considered suitable for selection. Studies on maxillary and/or mandible radiological findings have a positive correlation in the majority of the cases (18 positive vs. three negative), whereas the findings on clinical periodontal examination are inconclusive (six positive vs. five negative). There were ten studies in which a diagnosis of osteoporosis was made, based on the existence of non-traumatic fracture, while there were nine studies using radiographs for diagnosis, of which six studies were found to have a positive correlation. There was only one study based on a clinical periodontal examination that found a positive correlation. Conclusions The majority of the studies suggested a relationship between osteoporosis and periodontitis. Further well-controlled studies are needed to better elucidate the inter-relationship between systemic and oral bone loss and to clarify whether dentists could usefully give an early warning for osteoporosis risk. © 2010 International Menopause Society.