Cartagena, Colombia
Cartagena, Colombia

The University of Cartagena , also called Unicartagena, is a public, departmental, coeducational, research university based primarily in the city of Cartagena, Bolívar, Colombia. The university offers education at undergraduate and postgraduate levels, which includes 2 doctorates.The university is member of the Association of Colombian Universities , the Iberoamerican Association of Postgraduate Universities , and the State University System . Wikipedia.

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Ion mobility spectrometry (IMS) is an analytical technique that separates ions in the gas phase under the influence of an electric field according to their size to charge ratio. We used electrospray ionization IMS-quadrupole mass spectrometry to study the mobility shifts of 2,4-lutidine with temperature or the introduction of several contaminants in the drift gas. We found the reduced mobility (K0) of 2,4-lutidine to decrease up to 24% when contaminants were introduced into the drift gas. We also show the significant variation of 2,4-lutidine's K0 with the drift tube temperature, 8.5% from 100 to 322 °C. These changes in 2,4-lutidine's mobility were due to variations in clustering by changes in temperature or contaminant concentration. This dependence of 2,4-lutidine's K0 with temperature and contamination in the drift gas makes this chemical standard unsuitable to calibrate the mobility scale. Despite these findings, 2,4-lutidine is still used for this purpose. The shortcomings of the IMS two-standard calibration and the incorrect use of the drift tube temperature for calibration are also discussed. We suggest that accurate reduced mobilities must be determined for small ions only in a highly purified drift gas using calibrants with a well determined K0 such as di tert-butyl pyridine at high temperatures, where clustering is low, and the drift gas temperature is measured instead of the drift tube temperature. © 2017 The Royal Society of Chemistry.

Fernandez-Maestre R.,University of Cartagena
International Journal of Mass Spectrometry | Year: 2017

Ion mobility spectrometry (IMS) separates gas-phase ions drifting under an electric field according to their size to charge ratio. We used electrospray ionization-drift tube IMS coupled to quadrupole mass spectrometry to obtain the mobilities of common amino acids, amines, valinol, atenolol, and the chemical standards tetramethylammonium ion (TMA), tetraethylammonium ion (TEA), tetrapropylammonium ion (TPA), and tetrabutylammonium (TBA) ions, 2,4-lutidine and 2,6-di-tert-butyl pyridine (DTBP). The mobilities were obtained in pure nitrogen or when shift reagents (SR) such as ammonia, 2-butanol, ethyl lactate, methanol, methyl 2-chloropropionate, nitrobenzene, 1-phenyl ethanol, trifluoromethyl benzyl alcohol, and water were introduced in the buffer gas. We found important differences in the buffer gas temperature between different regions of the drift tube and differences between the buffer gas and drift tube temperatures, which is normally used instead of the buffer gas temperature in reduced mobility calculations. Therefore, we used the buffer gas temperature instead of the drift tube temperature and a calibration method with two types of chemical standards, finding excellent precision, reproducibilities from 0.3 to 0.6% for reduced mobilities (K0 ) of the chemical standards during nine months. Repeatability during this period was 0.17% for the drift times of all the analytes. We also show that the changes in instrumental parameters such as temperature, pressure and voltage that produce important variations in drift times are small; for this, we recommend to calculate K0 from calibration with chemical standards instead of replacing instrumental parameters in the IMS fundamental equations. © 2017 Elsevier B.V.

Fernandez-Maestre R.,University of Cartagena
International Journal for Ion Mobility Spectrometry | Year: 2017

Electrospray ionization IMS coupled to quadrupole mass spectrometry was used to calculate the reduced ion mobilities of aspartame, cortisone, betamethasone, butylparaben, propylparaben and vanillin, a set of organic compounds used as drugs or food additives using 2,6-ditert-butylpyridine (DTBP) as a chemical standard. The K0’S of these compounds in the literature are either unavailable or unreliable. The importance of using chemical standards to calibrate the ion mobility scale and the use of correct experimental temperatures to calculate ion mobilities are stressed. © 2017 Springer-Verlag Berlin Heidelberg

News Article | November 18, 2016

Water is vital for our survival. However, water quality is always a concern for public health authorities as it may contain diverse environmental pollutants, including endocrine disrupting chemicals (EDCs). Endocrine disrupting chemicals are one group of potentially hazardous substances that comprise natural and synthetic chemicals, with the ability to mimic endogenous hormones or interfere with their biosynthesis, metabolism, and normal functions. Common examples are bisphenol A, triclosan, phthalates, lead, mercury, nickel and polychlorinated biphenyls, among others. Fish are known to be quite sensitive to the effects of EDCs and therefore, are employed as research models to study the possible impacts of these chemicals in humans. In a review led by Purdue University (USA) and the University of Cartagena (Colombia), a team of researchers has proposed the zebrafish as a model to predict the effects of EDCs on humans using toxicogenomic tools, such as microarrays or whole-genome sequencing. This is possible due to the fact that zebrafish genes that have significantly altered expression after exposure to EDCs are very similar to those found in humans. In addition, many of the glandular system found in zebrafish have similarities with those in humans, making this fish model suitable to study alterations on the endocrine system. According to the authors, vitellogenin and aromatase cytochrome P450 are key genes that can be monitored in zebrafish to detect the presence of EDCs in water samples, especially at environmentally relevant concentrations. Toxicogenomic tools also offer the possibility to find new mechanisms by which EDCs alter the reproductive status of zebrafish, allowing its use to test the safety of new products entering the market. The possibilities are immense and the goal is to continue finding new markers of toxicity, and therefore alternative bridges to link EDC exposure to common diseases in humans. Co-authors of the paper include Karina Caballero-Gallardo, Jesus Olivero-Verbel (University of Cartagena, Cartagena, Colombia) and Jennifer L. Freeman (Purdue University, USA). For more information about the article, please visit http://benthamscience. Reference: Caballero-Gallardo, K.; et al (2016). Toxicogenomics to Evaluate Endocrine Disrupting Effects of Environmental Chemicals Using the Zebrafish Model., DOI: 10.2174/1389202917666160513105959

Olivero-Verbel J.,University of Cartagena
Reviews of Environmental Contamination and Toxicology | Year: 2011

The hexachlorocyclohexanes (HCHs) are synthetic compounds that have been widely used for the control of pests. The most common HCH isomers are the α-, β, δ-, and γ-HCH. Although they have the same chlorine substitution pattern, the spatial orientation of chlorine atoms is different on each one of them, resulting in unique structures that have distinct molecular properties. Humans are exposed to individual HCH isomers through various routes, including ingestion of contaminated water or food, absorbed through the skin or by inhalation, and because of their liposolubility, these chemicals are mostly stored in fat-containing tissues. The isomer-specific spectrum of biochemical actions for these compounds has been well characterized for different endpoints such as enzyme activation, calcium homeostasis, gap junctional intercellular communication, endocrine disruption, and cancer, among others. The interaction with the GABA receptor has been one of the most extensively studied properties of the HCHs. For instance, γ-HCH acts as a GABA A channel blocker, whereas α-and β-HCH potentiate GABA-activated currents, all working as allosteric modulators of the receptor. The changes in calcium homeostasis elicited by HCHs are both isomer and cell-type specific. For example, in neurons, both the δ-and γ-isomers of HCH stimulate Ca 2+ influx through different voltage-gated Ca 2+ channels. In human neutrophils, α-, δ-, and γ-HCH, but not b-HCH, increase intracellular Ca 2+ concentrations. This isomer-dependent behavior is also similar to that observed for phospholipase A 2 activation and also correlates with oxidative stress generation. On the other hand, there are several lines of evidence suggesting that HCHs alter genomic integrity, and, therefore, these compounds have been classified as possibly carcinogenic to humans. Finally, HCHs have been reported to be endocrine disrupters. In fact, γ-and β-HCH have been shown to have weak estrogenic activity, and together with the α-and the δ-isomer, also interfere with steroidogenesis. In short, the HCH isomers are good examples of structurally related chemicals, for which the geometrical patterns present in each one of the different conformers create structures that possess specific mechanisms of action and toxicological properties. © 2011 Springer Science+Business Media, LLC.

Montes-Grajales D.,University of Cartagena | Olivero-Verbel J.,University of Cartagena
Toxicology Letters | Year: 2013

The xenoestrogen bisphenol A (2,2-bis-(p-hydroxyphenyl)-2-propane, BPA) is a known endocrine-disrupting chemical used in the fabrication of plastics, resins and flame retardants, that can be found throughout the environment and in numerous every day products. Human exposure to this chemical is extensive and generally occurs via oral route because it leaches from the food and beverage containers that contain it. Although most of the effects related to BPA exposure have been linked to the activation of the estrogen receptor (ER), the mechanisms of the interaction of BPA with protein targets different from ER are still unknown. Therefore, the objective of this work was to use a bioinformatics approach to identify possible new targets for BPA. Docking studies were performed between the optimized structure of BPA and 271 proteins related to different biochemical processes, as selected by text-mining. Refinement docking experiments and conformational analyses were carried out using LigandScout 3.0 for the proteins selected through the affinity ranking (lower than -8.0. kcal/mol). Several proteins including ERR gamma (-9.9. kcal/mol), and dual specificity protein kinases CLK-4 (-9.5. kcal/mol), CLK-1 (-9.1. kcal/mol) and CLK-2 (-9.0. kcal/mol) presented great in silico binding affinities for BPA. The interactions between those proteins and BPA were mostly hydrophobic with the presence of some hydrogen bonds formed by leucine and asparagine residues. Therefore, this study suggests that this endocrine disruptor may have other targets different from the ER. © 2013 Elsevier Ireland Ltd.

Colina-Marquez J.,University of Cartagena | MacHuca-Martinez F.,University of Valle | Puma G.L.,University of Nottingham
Environmental Science and Technology | Year: 2010

This study provides a systematic and quantitative approach to the analysis and optimization of solar photocatalytic reactors utilized in environmental applications such as pollutant remediation and conversion of biomass (waste) to hydrogen. Ray tracing technique was coupled with the six-flux absorption scattering model (SFM) to analyze the complex radiation field in solar compound parabolic collectors (CPC) and tubular photoreactors. The absorption of solar radiation represented by the spatial distribution of the local volumetric rate of photon absorption (LVRPA) depends strongly on catalyst loading and geometry. The total radiation absorbed in the reactors, the volumetric rate of absorption (VRPA), was analyzed as a function of the optical properties (scattering albedo) of the photocatalyst. The VRPA reached maxima at specific catalyst concentrations in close agreement with literature experimental studies. The CPC has on average 70% higher photon absorption efficiency than a tubular reactor and requires 39% less catalyst to operate under optimum conditions. The "apparent optical thickness" is proposed as a new dimensionless parameter for optimization of CPC and tubular reactors. It removes the dependence of the optimum catalyst concentration on tube diameter and photocatalyst scattering albedo. For titanium dioxide (TiO2) Degussa P25, maximum photon absorption occurs at apparent optical thicknesses of 7.78 for CPC and 12.97 for tubular reactors. © 2010 American Chemical Society.

Gomez-Estrada H.,University of Cartagena
Journal of ethnobiology and ethnomedicine | Year: 2011

Traditional remedies are an integral part of Colombian culture. Here we present the results of a three-year study of ethnopharmacology and folk-medicine use among the population of the Atlantic Coast of Colombia, specifically in department of Bolívar. We collected information related to different herbal medicinal uses of the local flora in the treatment of the most common human diseases and health disorders in the area, and determined the relative importance of the species surveyed. Data on the use of medicinal plants were collected using structured interviews and through observations and conversations with local communities. A total of 1225 participants were interviewed. Approximately 30 uses were reported for plants in traditional medicine. The plant species with the highest fidelity level (Fl) were Crescentia cujete L. (flu), Eucalyptus globulus Labill. (flu and cough), Euphorbia tithymaloides L. (inflammation), Gliricidia_sepium_(Jacq.) Kunth (pruritic ailments), Heliotropium indicum L. (intestinal parasites) Malachra alceifolia Jacq. (inflammation), Matricaria chamomilla L. (colic) Mentha sativa L. (nervousness), Momordica charantia L. (intestinal parasites), Origanum vulgare L. (earache), Plantago major L. (inflammation) and Terminalia catappa L. (inflammation). The most frequent ailments reported were skin affections, inflammation of the respiratory tract, and gastro-intestinal disorders. The majority of the remedies were prepared from freshly collected plant material from the wild and from a single species only. The preparation of remedies included boiling infusions, extraction of fresh or dry whole plants, leaves, flowers, roots, fruits, and seeds. The parts of the plants most frequently used were the leaves. In this study were identified 39 plant species, which belong to 26 families. There was a high degree of consensus from informants on the medical indications of the different species. This study presents new research efforts and perspectives on the search for new drugs based on local uses of medicinal plants. It also sheds light on the dependence of rural communities in Colombia on medicinal plants.

The present invention refers to recombinant DNA molecules codifying fused peptides from different allergens from Blomia tropicalis and Dermatophagoides pteronyssinus having potential usefulness in prevention and treatment of allergies caused by domestic mites. Specifically, the invention discloses fusion proteins composed by different fragments of allergens Der p 1, Der p 2, Der p 7, Der p 8, Blo t 5, Blo t 8, Blo t 18, Blo t 12 and Blo t 13 with reduced serum IgE reactivity in allergic and non allergic individuals. It also discloses methods for production of these molecules in an expression system based on E. coli and purification. The invention refers also to effective and safe vaccines.

The present invention refers to recombinant DNA molecules codifying fused peptides from different allergens from Blomia tropicalis and Dermatophagoides pteronyssinus having potential usefulness in prevention and treatment of allergies caused by domestic mites. Specifically, the invention discloses fusion proteins composed by different fragments of allergens Der p 1, Der p 2, Der p 7, Der p 8,Blo t 5, Blo t 8, Blo t 18, Blo t 12 and Blo t 13 with reduced serum IgE reactivity in allergic and non allergic individuals. It also discloses methods for production of these molecules in an expression system based on E. coli and purification. The invention refers also to effective and safe vaccines.

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