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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.

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.

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.

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.

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.

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