Co-operative University of Colombia
Bogota, Colombia

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Hernandez J.C.,Co-operative University of Colombia | Giraldo D.M.,University of Antioquia | Paul S.,Jean Monnet University | Urcuqui-Inchima S.,University of Antioquia
PLoS ONE | Year: 2015

Objectives: Neutrophils contribute to pathogen clearance through pattern recognition receptors (PRRs) activation. However, the role of PRRs in neutrophils in both HIV-1-infected [HIV-1(+)] and HIV-1-exposed seronegative individuals (HESN) is unknown. Here, a study was carried out to evaluate the level of PRR mRNAs and cytokines produced after activation of neutrophils from HIV-1(+), HESN and healthy donors. Methods: The neutrophils were stimulated with specific agonists for TLR2, TLR4 and TLR9 in the presence of HIV-1 particles. Pro-inflammatory cytokine production, expression of neutrophil activation markers and reactive oxygen species (ROS) production were analyzed in neutrophils from HESN, HIV-1(+) and healthy donors (controls). Results: We found that neutrophils from HESN presented reduced expression of PRR mRNAs (TLR4, TLR9, NOD1, NOD2, NLRC4 and RIG-I) and reduced expression of cytokine mRNAs (IL-1β, IL-6, IL-18, TNF-α and TGF-β ). Moreover, neutrophils from HESN were less sensitive to stimulation through TLR4. Furthermore, neutrophils from HESN challenged with HIV-1 and stimulated with TLR2 and TLR4 agonists, produced significantly lower levels of reactive oxygen species, versus HIV-1(+). Conclusions: A differential pattern of PRR expression and release of innate immune factors in neutrophils from HESN is evident. Our results suggest that lower neutrophil activation can be involved in protection against HIV-1 infection. © 2015 Hernandez et al.

The following article shows the process of building and validating a framework for the management of consistencies in class diagrams in UML, operating specifically on class diagrams, through the application of transformation rules, using both graph grammar and OCL (Object Constraint Language). The proposed framework, after examining the techniques of consistency management, operates on a class diagram, since this constitutes a structural diagram. This is even more important when modeling, and it facilitates the application of rules based on the treated techniques, thus contributing to provide the community of analysts and modelers with a support tool for the refinement and quality improvement of the diagrams. It also operates on a typical case of application to show the tool's advantages, thus making it easier to comprehend and understand. © The authors; licensee Universidad Nacional de Colombia.

Contreras Salas O.L.,Co-operative University of Colombia
IMSCI 2012 - 6th International Multi-Conference on Society, Cybernetics and Informatics, Proceedings | Year: 2012

Traditionally, multimedia systems have been used in teaching English, but the introduction of Information and Communication Technology, or ICT, in a "massive" way has provided the teachers with a powerful tool to motivate students. However, this has become an issue in schools of the state due to the absence of concepts and methods. In short, it is stated that the advance was obtained when Information and Communication Technology was suddenly introduced into the educational system, so this proposal was emphasized only in Web 2.0 specifically developing the work platform of the Inglés y Virtualidad program at the Universidad National Distance Education University Florida with YouTube and blogs as educational tools. This paper describes the results of a research project that shows how to integrate Web 2.0 technologies into the teaching of English in order to contribute to the formation of updated, collaborative and creative instructors. Hence, what is truly relevant in the process is to get teachers to make pedagogical use of new technologies.

Giraldo D.M.,University of Antioquia | Hernandez J.C.,Co-operative University of Colombia | Inchima S.U.,University of Antioquia
Intervirology | Year: 2015

Objective: HIV-1 infects several immune cells including dendritic cells (DCs) and monocytes, which contributes in both to dissemination of HIV-1 infection and induction of antiviral immunity. These cells produce high amounts of type I IFN and proinflammatory cytokines upon Toll-like receptor (TLR) stimulation. During HIV-1 infection, an altered production of proinflammatory cytokines has been reported. However, the mechanisms underlying cytokine modulation have not been well described. Here, we evaluated the production of proinflammatory cytokines and activation of myeloid and plasmacytoid DCs and monocytes costimulated in vitro with TLR agonists and HIV-1. Methods: Changes in cytokine expression by real-time PCR and activation of DCs and monocytes by flow cytometry were evaluated after costimulation with HIV-1 and TLR agonists. Results: We observed an upregulation of TNF-α expression after TLR4 stimulation, but a downregulation of IL-6 when TLR2/TLR9 were stimulated. Interestingly, the expression of CD80 and CD86 costimulatory molecules in monocytes and DCs were significantly increased in cells challenged with HIV-1 and TLR2/TLR4/TLR9 agonists. Conclusion: This regulation of TNF-α and IL-6 production and changes in the expression of costimulatory molecules can be critical in the context of HIV-1 infection, by favoring the antigen-presenting cell activation through the stimulation of TLRs. © 2015 S. Karger AG, Basel.

Diaz L.G.,Co-operative University of Colombia
International Journal of Pavement Research and Technology | Year: 2016

Cold Mix Asphalt (CMA) is commonly used in lieu of typical Hot Mix Asphalt (HMA) for localized pavement patching due to the quantities, intermittent locations and times when repairs need to be executed. The objective of this investigation was to evaluate the resistance of CMA to accumulate permanent deformation under cyclic loading, and to present an alternative to assess stability potential from a portable device. Considering CMA is at its weakest state right after placement, and that its resistance to creep improves with curing, the study focused on evaluating the rutting performance of uncured CMA materials at different compaction levels in the laboratory by means of parameters b and FN from a Modified Cyclic Creep Test (MCCT) and by their resistance to penetration with a Light Cone Penetrometer (LCP), defined by the LCP penetration rate (LPR). Based on the experimental results, acceptable laboratory stability can be expected when values below 0.5 με/load and over 1000 load cycles are observed for b and FN, respectively. Considering the potential use of the LCP as a field-friendly quality control tool, models to estimate parameters b and FN from the MCCT as a function of LPR and other CMA characteristics were developed using Multiple Linear Regression Analysis (MLRA). The results suggest that when LPR values are limited to 0.50 mm/blow, CMA materials can be expected to show acceptable stability levels. © 2016.

Hernandez J.C.,Co-operative University of Colombia | Latz E.,University of Massachusetts Medical School | Latz E.,University of Bonn | Urcuqui-Inchima S.,University of Antioquia
Intervirology | Year: 2013

Background/Aims: Inflammasomes are multimolecular complexes that regulate caspase-1. They act as sensors for endogenous and exogenous signals, and mediate the processing of pro-IL-1β into its secreted, biologically active form. The NLRP3 inflammasome and IL-1β are particularly interesting because they are required for efficient control of viral infections. Indeed, HIV-1 induces expression of NLRP3 and IL-1β in healthy controls, but not in HIV-1-infected patients. Here we evaluate whether HIV-1 can induce activation of the NLRP3 inflammasome. Methods: Human primary monocyte-derived macrophages were infected with HIV-1 in the absence or presence of classical NLRP3 inflammasome activators, and IL-1β release was assessed by ELISA. Results: HIV-1 initiates the priming signal for NLRP3 inflammasome activation through the NF-κB-associated pathway in human primary monocyte-derived macrophages. Furthermore, priming of NLRP3 activation in response to HIV-1 was independent of the viral envelope, since similar results were observed with HIV-1 and pseudotyped HIV-1 lacking the env gene. Conclusion: Our findings suggest that HIV-1 infection promotes IL-1β secretion by inducing the first signal for NLRP3 inflammasome activation, a phenomenon that may contribute to AIDS progression. Copyright © 2013 S. Karger AG, Basel.

Objective Describing the Emberá-Chamí Indians' traditional medical system (Caldas Department, Colombia). Methods This was an ethnographic study which involved 4 traditional doctors, 2 midwives, 3 healers, a faith-healer (medicine man) and 10 community members who were selected by theoretical sampling. Interviews, field diaries and participant observation were used in line with credibility, auditability and transferability criteria, and category saturation and methodological and theoretical triangulation. Results Traditional medicine, health, disease and healing were conceptualised, describing the system's therapeutic resources, links with biomedicine, spiritual domain components, the relevance of the Guardians and holy sites, the major rituals and roles of family, native physiotherapists, healers, medicine men/women, midwives and traditional faith-healing doctors. Conclusion Indigenous people have valuable knowledge about practices involving the body, social interactions, coexistence with nature and spiritual beings which is based on harmony and integral worldviews.

With the purpose of measuring production yields at a meat production farm, technical records for 597 crossbred Zebu steers fattened were examined in the period from 2006 to 2009 in municipality of Tame, in the department of Arauca, Colombia. Indicators of average daily gain (ADG), efficiency of production (EP), meat yield (R), meat yield per year (kg / animal / year) and of meat yield per hectare per year (kg / ha / year) were calculated. The data was analyzed using descriptive statistics. Year 2009 showed the best performance for GDP and kg / day / year yield was shown in year 2009 with 905 g and 330.3 kg and the lowest R 70.2% R, however, it was offset by efficiency production of meat / animal / year (365,5 kg). Meat production per area with 375 kg / ha / year excelled in 2007. The EP showed similar production for all years. It is concluded that in each period there is a wide variation in production due to initial weight and environmental conditions of each year. © 2014,Instituto Nacional de Investigaciones Agricolas (INIA). All rights reserved.

Martignon S.,El Bosque University | Chavarria N.,Co-operative University of Colombia | Ekstrand K.R.,Copenhagen University
Clinical Oral Investigations | Year: 2010

Studies have indicated that many initial proximal caries lesions progress and are eventually restored even if the patients have been under comprehensive preventive programmes. The objectives of the study were (1) to describe the 1996-year baseline caries status of male Danish conscripts and (2) to assess their early proximal lesions 6-year behaviour. In 1996, all 20-year-old conscripts at Central Barrack Birkerød (n = 115) went through an oral examination, including visual surface-level fillings' recording and a radiographic examination with bitewing radiographs that assessed the proximal-surface caries and restoration patterns. After 6 years, the behaviour of proximal lesions was studied in 73 of these subjects, and oral health habits were assessed through a questionnaire. Mean number of filled surfaces was 7.5, of which 23% were posterior proximal. Radiographically, the mean number of proximal lesions was 5. 5. Over the 6-year period, there was progression of lesions into deeper radiolucencies or fillings in 57% of cases. The questionnaire showed a poor compliance with regular flossing/tooth-stick use (18%). Based on these results, more efficacious preventive measures seem to be needed for proximal surfaces. © 2009 Springer-Verlag.

Hernandez J.C.,University of Antioquia | Hernandez J.C.,Co-operative University of Colombia | Stevenson M.,University of Miami | Latz E.,University of Bonn | And 2 more authors.
AIDS Research and Human Retroviruses | Year: 2012

Toll-like receptors (TLRs) play a critical role in innate immunity against pathogens. Their stimulation induces the activation of NF-κB, an important inducer of HIV-1 replication. In recent years, an increasing number of studies using several cells types from HIV-infected patients indicate that TLRs play a key role in regulating the expression of proinflammatory cytokines and viral pathogenesis. In the present study, the effect of HIV-1 stimulation of monocyte-derived macrophage (MDM) and peripheral blood mononuclear cell (PBMC) subpopulations from healthy donors on the expression and functions of TLR2 and TLR4 was examined. In addition, and to complete the in vitro study, the expression pattern of TLR2 and TLR4 in 49 HIV-1-infected patients, classified according to viral load and the use of HAART, was determined and compared with 25 healthy subjects. An increase of TLR expression and production of proinflammatory cytokines were observed in MDMs and PBMCs infected with HIV-1 in vitro and in response to TLR stimulation, compared to the mock. In addition, an association between TLR expression and up-regulation of CD80 in plasmacytoid dendritic cells (pDCs) was observed. The ex vivo analysis indicated increased expression of TLR2 and TLR4 in myeloid dendritic cells (mDCs), but only of TLR2 in monocytes obtained from HIV-1-infected patients, compared to healthy subjects. Remarkably, the expression was higher in cells from patients who do not use HAART. In monocytes, there was a positive correlation between both TLRs and viral load, but not CD4+ T cell numbers. Together, our in vitro and ex vivo results suggest that TLR expression and function can be up-regulated in response to HIV-1 infection and could affect the inflammatory response. We propose that modulation of TLRs represents a mechanism to promote HIV-1 replication or AIDS progression in HIV-1-infected patients. © 2012, Mary Ann Liebert, Inc.

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