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Morales-Ovalles Y, Miranda-Contreras L, Peña-Contreras Z, Dávila-Vera D, Balza-Quintero A, Sánchez-Gil B, Mendoza-Briceño RV. Developmental exposure to mancozeb induced neurochemical and morphological alterations in adult male mouse hypothalamus. Environ Toxicol Pharmacol 2018; 64:139-146. [PMID: 30391875 DOI: 10.1016/j.etap.2018.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 10/11/2018] [Accepted: 10/16/2018] [Indexed: 06/08/2023]
Abstract
Mancozeb, a dithiocarbamate widely used in agriculture, is considered a developmental hazard in humans; however, more evidences are still needed concerning the consequences of chronic exposure to this pesticide. Mancozeb neurotoxicity in developing mouse hypothalamus was evaluated by subchronic exposure of male Mus musculus mice to low and high doses of mancozeb (30 and 90 mg/kg body weight, respectively) from late neonatal until adolescence. Variations in hypothalamic amino acid neurotransmitter levels and changes in histological as well as cytological characteristics were analyzed in young adult experimental mice and compared with control. A dose-dependent increase in excitation/ inhibition ratio was observed in mancozeb-exposed hypothalamus, indicating an overall state of excitoxicity. Histopathological and ultrastructural studies showed increased apoptosis, neuroinflammation and demyelination, demonstrating mancozeb-induced cytotoxicity in hypothalamic neurosecretory cells. In summary, both neurochemical and morphological data revealed mancozeb-induced alterations during development of hypothalamic circuitry that are critical for maturation of the neuroendocrine system.
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Affiliation(s)
- Yasmin Morales-Ovalles
- Electron Microscopy Center "Dr. Ernesto Palacios Prü", University of Los Andes, Mérida, Venezuela
| | | | - Zulma Peña-Contreras
- Electron Microscopy Center "Dr. Ernesto Palacios Prü", University of Los Andes, Mérida, Venezuela
| | - Delsy Dávila-Vera
- Electron Microscopy Center "Dr. Ernesto Palacios Prü", University of Los Andes, Mérida, Venezuela
| | - Alirio Balza-Quintero
- Electron Microscopy Center "Dr. Ernesto Palacios Prü", University of Los Andes, Mérida, Venezuela
| | - Beluardi Sánchez-Gil
- Electron Microscopy Center "Dr. Ernesto Palacios Prü", University of Los Andes, Mérida, Venezuela
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Rondón J, Gómez W, Ball MM, Melfo A, Rengifo M, Balcázar W, Dávila-Vera D, Balza-Quintero A, Mendoza-Briceño RV, Yarzábal LA. Diversity of culturable bacteria recovered from Pico Bolívar's glacial and subglacial environments, at 4950 m, in Venezuelan tropical Andes. Can J Microbiol 2016; 62:904-917. [PMID: 27564086 DOI: 10.1139/cjm-2016-0172] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Even though tropical glaciers are retreating rapidly and many will disappear in the next few years, their microbial diversity remains to be studied in depth. In this paper we report on the biodiversity of the culturable fraction of bacteria colonizing Pico Bolívar's glacier ice and subglacial meltwaters, at ∼4950 m in the Venezuelan Andean Mountains. Microbial cells of diverse morphologies and exhibiting uncompromised membranes were present at densities ranging from 1.5 × 104 to 4.7 × 104 cells/mL in glacier ice and from 4.1 × 105 to 9.6 × 105 cells/mL in subglacial meltwater. Of 89 pure isolates recovered from the samples, the majority were eurypsychrophilic or stenopsychrophilic, according to their temperature range of growth. Following analysis of their 16S rDNA nucleotidic sequence, 54 pure isolates were assigned to 23 phylotypes distributed within 4 different phyla or classes: Beta- and Gammaproteobacteria, Actinobacteria, and Bacteroidetes. Actinobacteria dominated the culturable fraction of glacier ice samples, whereas Proteobacteria were dominant in subglacial meltwater samples. Chloramphenicol and ampicillin resistance was exhibited by 73.07% and 65.38%, respectively, of the subglacial isolates, and nearly 35% of them were multiresistant. Considering the fast rate at which tropical glaciers are melting, this study confirms the urgent need to study the microbial communities immured in such environments.
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Affiliation(s)
- Johnma Rondón
- a Laboratorio de Microbiología Molecular y Biotecnología, Facultad de Ciencias, Núcleo de La Hechicera, Universidad de Los Andes, Av. Alberto Carnevalli, Mérida 5101, Estado Mérida, Venezuela
| | - Wileidy Gómez
- a Laboratorio de Microbiología Molecular y Biotecnología, Facultad de Ciencias, Núcleo de La Hechicera, Universidad de Los Andes, Av. Alberto Carnevalli, Mérida 5101, Estado Mérida, Venezuela
| | - María M Ball
- a Laboratorio de Microbiología Molecular y Biotecnología, Facultad de Ciencias, Núcleo de La Hechicera, Universidad de Los Andes, Av. Alberto Carnevalli, Mérida 5101, Estado Mérida, Venezuela
| | - Alejandra Melfo
- b Centro de Física Fundamental, Facultad de Ciencias, Núcleo de La Hechicera, Universidad de Los Andes, Av. Alberto Carnevalli, Mérida 5101, Estado Mérida, Venezuela
| | - Marcos Rengifo
- a Laboratorio de Microbiología Molecular y Biotecnología, Facultad de Ciencias, Núcleo de La Hechicera, Universidad de Los Andes, Av. Alberto Carnevalli, Mérida 5101, Estado Mérida, Venezuela
| | - Wilvis Balcázar
- a Laboratorio de Microbiología Molecular y Biotecnología, Facultad de Ciencias, Núcleo de La Hechicera, Universidad de Los Andes, Av. Alberto Carnevalli, Mérida 5101, Estado Mérida, Venezuela
| | - Delsy Dávila-Vera
- c Centro de Microscopía Electrónica Dr. Ernesto Palacios Prü, Vicerrectorado Académico, Universidad de Los Andes, Av. Tulio Febres Cordero, Mérida 5101, Estado Mérida, Venezuela
| | - Alirio Balza-Quintero
- c Centro de Microscopía Electrónica Dr. Ernesto Palacios Prü, Vicerrectorado Académico, Universidad de Los Andes, Av. Tulio Febres Cordero, Mérida 5101, Estado Mérida, Venezuela
| | - Rosa Virginia Mendoza-Briceño
- c Centro de Microscopía Electrónica Dr. Ernesto Palacios Prü, Vicerrectorado Académico, Universidad de Los Andes, Av. Tulio Febres Cordero, Mérida 5101, Estado Mérida, Venezuela
| | - Luis Andrés Yarzábal
- a Laboratorio de Microbiología Molecular y Biotecnología, Facultad de Ciencias, Núcleo de La Hechicera, Universidad de Los Andes, Av. Alberto Carnevalli, Mérida 5101, Estado Mérida, Venezuela.,d Laboratorio de Biología Molecular, Carrera de Ingeniería Agronómica, Facultad de Ciencias Agropecuarias, Universidad de Cuenca, Av. 12 de Octubre, Cuenca, Ecuador
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Flores-García ME, Molina-Morales Y, Balza-Quintero A, Benítez-Díaz PR, Miranda-Contreras L. [Pesticide residues in drinking water of an agricultural community in the state of Mérida, Venezuela]. Invest Clin 2011; 52:295-311. [PMID: 22523840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The aim of this study was to determine the presence of pesticides in drinking water from six aqueducts in a region of intense agricultural activity in the state of Merida, Venezuela. The study was conducted for four continuous weeks, between May and June 2008. Pesticide residues were analyzed by solid phase extraction (SPE) and liquid chromatography (HPLC) with diode array detector (DAD). The method SPE-HPLC-DAD met the criteria of analytical validation, with good linearity (R2: 0.9840 to 0.9999), precision (coefficient of inter-day variability from 1.47 to 6.25%), accuracy (relative standard deviation 0.9 to 9.20%) and sensitivity (LOD < or = 0.012 microg/L; LOQ < or = 0.030 microg/L, except mancozeb with 0.400 microg/L). Seven of the thirteen selected pesticides have a recovery rate between 100% and 70%, the rest between 61% and 37%. Ten pesticides of the following chemical groups, were detected in 72 samples analyzed: organophosphates, carbamates, triazines and urea derivatives. The pesticides with the highest frequency of detection were: carbofuran and atrazine (39%), malathion (25%), dimethoate and metribuzin (19%). The pesticides found at high levels were diazinon (26.31 microg/L), methamidophos (10.99 microg/L), malathion (2.03 microg/L) and mancozeb (1.27 microg/L). Pesticide levels did not exceed the maximum allowed by Venezuelan law, however, according to international standards (EU and EPA-USA) values were above the maximum permissible levels. This study demonstrates the urgent need for systematic monitoring of the quality of water for human consumption in regions of high agricultural productivity.
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Affiliation(s)
- Mery Elisa Flores-García
- Centro de Microscopía Electrónica "Dr Ernesto Palacios Prü", Universidad de Los Andes, Mérida, Venezuela
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