Browsing by Autor "Nelva Deyanira Lara"

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Biomarcadores de metabolismo óseo y su utilidad en la osteoporosis
(2019) José Ramón Vielma Guevara; David Picón-Borregales; Nelva Deyanira Lara; Luis Vicente Gutiérrez-Peña
The aim of the work is to describe the main biomarkers of bone metabolism, grouped as: classical (specific, mineralization, formation, and resorption), oxidative stress, and new biomarkers or biomarkers under study, and their usefulness in osteoporosis and other bone diseases. These biomarkers are chemicals secreted primarily by bone cells (osteoblasts and osteoclasts) that are released into the bloodstream and can be determined primarily in the blood and/or urine. Other cells, and even endocrine glands, can produce these substances or compounds. Biomarkers of bone metabolism are the reflection of the dynamics of every bone in our body, as well as the bone turnover. This feature gives them added value and differentiates them from bone densitometry and x-ray, as they provide a static picture of a specific site of the skeleton, for example hip, femur, spine.
Fisiopatología de la osteoporosis: genes, estrés oxidativo e inmunopatogenia. Una revisión sistemática cualitativa
(Universidad de Los Andes, 2018) José Ramón Vielma Guevara; David Picón; Luis Vicente Gutiérrez; Nelva Deyanira Lara
The aim of this qualitative systematic review is to describe the most important pathophysiological factors related with genes, oxidative stress, immunophatogeny and others aspects in osteoporosis. We selected Pubmed, Scielo and Google Scholar databases. A total of 7,730 documents were returned, based on different combinations of keywords in English and Spanish. We use the quick reading of titles and abstracts to eliminate the articles unrelated to the proposed expository scheme. A total of 152 papers fulfilled the following validation criteria: descriptive clinical studies, comparative with control group, analytical studies of random assignment, and studies in experimental animals. To evaluate the methodological quality of the clinical studies, the Sackett evidence scale was used, and the list of criteria of Sniekers to analyze the quality of the animal studies were used. A major challenge is the integration of a multitude of signaling pathways and redundant cytokines, oxidative stress, chronic stress, genes, among others, apparently capable of playing an important role, in trying to establish a complete model of the pathophysiology of postmenopausal osteoporosis.
Metales pesados en tejidos blandos de cangrejo azul (Callinectes sapidus) de Puerto Concha, municipio Colón, estado Zulia
(Universidad de Los Andes, 2018) Luís Vicente Gutiérrez Peña; David Picón; Iserslis A. Gutiérrez; Milton Prada; Pablo Carrero; Yelitza Josefina Delgado Cayama; Ever O. Gutiérrez; Miguel Ángel Morón; Carlos E. González; Nelva Deyanira Lara
To aim was determine the concentrations of heavy metals in soft tissues of blue crab (Callinectes sapidus) in Puerto Concha, Colon municipality, Zulia state. The study was descriptive and experimental. For this, a sampling consisting of 37 catches were taken during almost three years, from April 2007 to February 2010. Determinations of heavy metals: lead (Pb), cadmium (Cd), nickel (Ni), chromium (Cr), cobalt (Co), arsenic (As), manganese (Mn), copper (Cu), vanadium (V) and thallium (Tl) by electrothermal atomic absorption spectrophotometry (ETAAS) were quantified. The results were expressed in mg/kg dry mass. The average concentrations of heavy metals did not exceed the permitted limits, however the presence of highly toxic metals such as Pb, Cd, As and Cr with unknown biological function is cause for concern and alert. The presence of toxic metals in soft tissues of blue crab, leads us to propose the study of these metals in living organisms, water and sediments near the affluent of the rivers, to detect the possible sources of pollution and take correctives to curb the entry of these elements into the environment (avoiding progressive deterioration of Maracaibo Lake). Callinectes sapidus is a key species in the studied ecosystem and could play an important role in transferring contaminants to higher trophic levels and the presence of these elements may raise concern for local biota.