Examinando por Autor "Gómez-Ramírez, Edwin"

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  • Publicación
    Acceso abierto
    Anatomía general, histología y morfometría del sistema digestivo del pez pterophyllum scalare (Perciformes: cichlidae)
    (2020-12-05) Ramírez-Espitia, Edith Juliana; Hurtado-Giraldo, Hernan; Gómez-Ramírez, Edwin; Neurociencias
    Introduction: Ornamental Angel fish (Pterophyllum scalare) is one of the main commercialized species from South America, with an important number of national and international dealers. Objective: To make a histological and morphometric description of P. scalare digestive tract. Methods: Nineteen adult individuals were used. Intestinal coefficient values were obtained, and a macroscopic and microscopic description of esophagus, stomach, and intestine (anterior, middle and posterior) was carried out. Samples were processed for paraffin embedding, and 5 µm sections were stained with H&E and P.A.S. Positive P.A.S. cells were counted. Lumen area and tissue area were measured in representative digitalized sections from each region. Results: P. scalare exhibited a short esophagus, followed by a blind bag shaped, scarcely muscular stomach, and a short intestine (intestinal coefficient 1.66 +/- 0.52). Four constitutive tissue layers were identified: mucosa, submucosa, muscular and in some areas also a serosa layer. Esophagus exhibit abundant globet P.A.S. + cells and shows the larger tisular area was observed. Luminal area and perimeter are larger in anterior intestinal region. Conclusions: the intestinal coefficient value (1.66 +/- 0.52), and the histological and morphometric characteristics of the evaluated organs, suggest that P. scalare is omnivorous with soft prey preferences.
  • Publicación
    Acceso abierto
    Glyphosate commercial formulation effects on preoptic area and hypothalamus of cardinal neon paracheirodon axelrodi (Characiformes: Characidae)
    (2019-12-13) Riaño-Quintero, Camilo; Gómez-Ramírez, Edwin; Hurtado-Giraldo, Hernan; Nuero Ciencias
    In Colombia the use of glyphosate commercial formulations (Roundup™) for spraying have left deleterious effects on animals and humans. Much of this spraying takes place at the Orinoco basin, habitat of one of the most exported ornamental fish in Colombia, Cardinal neon. To evaluate the effect of Roundup Activo™ four experimental treatments were carried out with 0 mg/L (T1), 0.1 mg/L (T2), 1 mg/L (T3) and 5 mg/L (T4) during 30 days of exposure. The fishes were processed for highresolution optical microscopy. The main finding of Roundup Activo™ exposure was an increase in mast cells number in brain blood vessels and some neuronal nuclei of the preoptic and posterior diencephalic areas, including hypothalamus. A correlation between concentrations and mast cells number was observed, with the largest mast cells number in T4 treatment. Mast cells presence is a stress benchmark, suggesting the beginning of allergic, inflammatory and apoptotic events. Presence of mast cells in these brain areas may lead to alterations on reproduction, visual and olfactory information integration among other processes. These alterations may result in diminished survival, affecting the conservation of this species in its natural habitat.