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Bogotá, Colombia

Iris Suarez M.,University of Antioquia | Uribe D.,University of Antioquia | Jaramillo C.M.,University of Antioquia | Osorio G.,University of Antioquia | And 6 more authors.
Annals of Hepatology

Background and aim: Hepatocellular carcinoma (HCC) is the most common primary liver cancer diagnosed worldwide. Deregulation of Wnt/β-catenin pathway has been associated with the development of HCC in a substantial number of cases in Europe and far less in Asia. Nothing is known about this pathway in HCC cases from South America. This study aimed to investigate the frequency of mutations in β-catenin gene (CTNNB1) and the subcellular localization of β-catenin in HCC cases from Colombia.Material and methods: We determine by direct sequencing the frequency of mutations in exon 3 of CTNNB1 gene and by immunohistochemistry the subcellular localization of β-catenin in 54 samples of HCC obtained from three pathology units in Bogota and Medellin cities.Results: Only three HCC cases (5.6%) were found mutated at residues (G34E, S45P, P44S, T41I) important for phosphorylation and ubiquitination of β-catenin protein. Strikingly, nuclear or cytoplasmic accumulation of β-catenin, hallmark of Wnt pathway activation, was found in 42.6% HCC cases (23/54). Interestingly, β-catenin accumulation was significantly more frequent in young patients and hepatitis B virus-related HCC.Conclusions: Although, CTNNB1 exon 3 mutations are not frequent in HCC from Colombian patients, our findings indicate that Wnt/β-catenin signaling is activated in 42.6% of HCC samples. Furthermore, Wnt signaling was demonstrated in HCC cases associated of HBV infection, one of the most important HCC risk factors in Colombia. © 2014 Annals of Hepatology. All rights reserved. Source

Park S.K.,University of Michigan | Auchincloss A.H.,Drexel University | O'Neill M.S.,University of Michigan | Prineas R.,Wake forest University | And 6 more authors.
Environmental Health Perspectives

Background: Cardiac autonomic dysfunction has been suggested as a possible biologic pathway for the association between fine particulate matter ≤ 2.5 μm in diameter (PM 2.5) and cardiovascular disease (CVD). We examined the associations of PM 2.5 with heart rate variability, a marker of autonomic function, and whether metabolic syndrome (MetS) modified these associations. Methods: We used data from the Multi-Ethnic Study of Atherosclerosis to measure the standard deviation of normal-to-normal intervals (SDNN) and the root mean square of successive differences (rMSSD) of 5,465 participants 45-84 years old who were free of CVD at the baseline examination (2000-2002). Data from the U.S. regulatory monitor network were used to estimate ambient PM 2.5 concentrations at the participants' residences. MetS was defined as having three or more of the following criteria: abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol, high blood pressure, and high fasting glucose. Results: After controlling for confounders, we found that an interquartile range (IQR) increase in 2-day average PM 2.5 (10.2 μg/m 3) was associated with a 2.1% decrease in rMSSD [95% confidence interval (CI), -4.2 to 0.0] and nonsignificantly associated with a 1.8% decrease in SDNN (95% CI, -3.7 to 0.1). Associations were stronger among individuals with MetS than among those without MetS: an IQR elevation in 2-day PM 2.5 was associated with a 6.2% decrease in rMSSD (95% CI, -9.4 to -2.9) among participants with MetS, whereas almost no change was found among participants without MetS (p-interaction = 0.005). Similar effect modification was observed in SDNN (p-interaction = 0.011). Conclusion: These findings suggest that autonomic dysfunction may be a mechanism through which PM exposure affects cardiovascular risk, especially among persons with MetS. Source

Solano M.E.,El Rosario University | Castillo I.,University of La Sabana | Nino De Mejia M.C.,Fundacion Santa Fe de Bogota
Revista Colombiana de Anestesiologia

in neurosurgical procedures. A few years back there used to be some medical skepticism about the potential of cerebral ischemia and today we know that it is detrimental and worsens the patient's condition and prognosis. Objective: To review the adverse effects of hypocapnia on various organs -mainly the brain- and to identify the current recommendations about its use. Methodology: We conducted a PubMed literature search using MeSH terminology including the key words. The search was expanded to include a review of several texts and the bibliography of the most relevant articles. Results: The literature review showed that hypocapnia is harmful for the brain and for other tissues and the current recommendation is to use it for two situations only: in case of imminent herniation and to improve the surgical field, limited to 20 minutes. Conclusions: Hyperventilation should not be a routine anesthetic intervention for the management of the neurosurgical patient; there must be a precise indication and once the situation is corrected, the intervention must be immediately withdrawn. © 2011 Sociedad Colombiana de Anestesiología y Reanimación. Source

Yepes S.,National University of Colombia | Torres M.M.,National University of Colombia | Torres M.M.,University of Los Andes, Colombia | Saavedra C.,Fundacion Santa Fe de Bogota | And 2 more authors.
World Journal of Gastroenterology

AIM: To assess the significance of chromosome translocation t(11;18)(q21;q21), B-cell lymphoma 10 (BCL-10) protein and Helicobacter pylori (H. pylori) infection in gastric mucosa-associated lymphoid tissue (MALT) lymphoma in Colombia. METHODS: Fifty cases of gastric MALT lymphoma and their respective post-treatment follow-up biopsies were examined to assess the presence of the translocation t(11;18)(q21;q21) as identified by fluorescence in situ hybridization; to detect protein expression patterns of BCL10 using immunohistochemistry; and for evaluation of tumor histology to determine the correlation of these factors and resistance to H. pylori eradication. RESULTS: Infection with H. pylori was confirmed in all cases of gastric MALT lymphoma in association with chronic gastritis. Bacterial eradication led to tumor regression in 66% of cases. The translocation t(11;18)(q21;q21) was not present in any of these cases, nor was there evidence of tumor transformation to diffuse large B-cell lymphoma. Thirty-four percent of the patients showed resistance to tumor regression, and within this group, 7 cases, representing 14% of all those analyzed, were considered to be t(11;18)(q21;q21)-positive gastric MALT lymphomas. Protein expression of BCL10 in the nucleus was associated with the presence of translocation and treatment resistance. Cases that were considered unresponsive to therapy were histologically characterized by the presence of homogeneous tumor cells and a lack of plasmacytic differentiation. Responder cases exhibited higher cellular heterogeneity and a greater frequency of plasma cells. CONCLUSION: Both t(11;18)(q21;q21)-positive MALT lymphoma cases and those with nuclear BCL10 expression are considered resistant to H. pylori eradication. It is suggested that chronic antigenic stimulation is not a dominant event in resistant cases. © 2012 Baishideng. All rights reserved. Source

Salazar A.J.,University of Los Andes, Colombia | Camacho J.C.,Fundacion Santa Fe de Bogota | Aguirre D.A.,Fundacion Santa Fe de Bogota
Telemedicine and e-Health

Objective: Film digitizers are a specialized technology that is available for scanning X-ray radiographs; however, their cost makes them unaffordable for developing countries. Thus, less expensive alternatives are used. The purpose of this study was to compare three devices for digital capture of X-ray films: a film digitizer (US $15,000), a flatbed scanner (US $1800), and a 10-megapixel digital camera (US $450), in terms of diagnostic accuracy, defined as the area under the receiver operating characteristic curves and computed tomography as the gold standard. Materials and Methods: The sample included 136 chest X-ray cases with computed tomography confirmation of the presence or absence of pneumothorax, interstitial opacities, or nodules. The readers were six radiologists who made observations of eight variables for each digital capture of the X-ray films: three main variables to determine the accuracy in the detection of the above-mentioned pathologies, four secondary variables to categorize other pathological classifications, and one variable regarding digital image quality. Results: The receiver operating characteristic curves for each device and pathology were very similar. For the main variables, there was no significant statistical difference in diagnostic accuracy between the devices. For the secondary variables, >84% of cases were correctly classified, even those that were classified with the lowest image quality. High accuracy was determined for the three main variables (0.75 to 0.96), indicating good performance for all tested devices, despite their very different prices. Conclusions: Choosing a device for a teleradiology service should involve additional factors, such as capture time, maintenance concerns, and training requirements. © 2011, Mary Ann Liebert, Inc. Source

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