Peña Melián, Ángel

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First Name
Last Name
Peña Melián
Universidad Complutense de Madrid
Faculty / Institute
Anatomía y Embriología Humana
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Now showing 1 - 4 of 4
  • Publication
    Ciliary muscle in avian is derived from mesenchymal and epithelial cells
    (Elsevier, 2002-06) Barrio Asensio, María del Carmen; Peña Melián, Ángel; Puerta Fonollá, Javier; Vázquez Osorio, María Teresa; Murillo González, Jorge Alfonso
    It has long been maintained that the ciliary muscle derives from mesenchymal cells. The embryonic development of the avian ciliary muscle was studied in chick embryos from stage 25 HH to the time of hatching. Serial sections of the eye were stained routinely or immunocytochemically using the monoclonal antibody 13F4, which recognizes a cytoplasmic antigen specific for all types of muscle cells. We found that the mesenchymal immunoreactive cells, at stage 37 HH, are arranged in two distinct orientations forming the anterior and posterior portions of the ciliary muscle. At stages 38 and 39 HH the pigmented epithelium contained 13F4 positive cells, which detach from the epithelium and apparently migrate into stroma. These epithelial cells may differentiate into muscle cells. Within this same time period a progressive accumulation of myoblasts was detected between the pigmented epithelium and the ciliary muscle. Some myoblasts containing melanin were also observed. At stage 40 HH the internal portion of the ciliary muscle was visible. These findings indicate that the immunopositive epithelial cells participate in the formation of the internal portion of the muscle. We conclude that the ciliary muscle derives not only from the mesenchymal cells but also from the pigmented epithelium.
  • Publication
    Low and high dietary folic acid levels perturb postnatal cerebellar morphology in growing rats
    (Cambridge University Press, 2016-06-14) Partearroyo Cediel, Teresa; Pérez Miguelsanz, Juliana; Peña Melián, Ángel; Maestro de las Casas, Carmen; Úbeda Martín, Natalia; Valera Moreiras, Gregorio
    The brain is particularly sensitive to folate metabolic disturbances, because methyl groups are critical for brain functions. This study aimed to investigate the effects of different dietary levels of folic acid (FA) on postnatal cerebellar morphology, including the architecture and organisation of the various layers. A total of forty male OFA rats (a Sprague–Dawley strain), 5 weeks old, were classified into the following four dietary groups: FA deficient (0 mg/kg FA); FA supplemented (8 mg/kg FA); FA supra-supplemented (40 mg/kg FA); and control (2 mg/kg FA) (all n 10 per group). Rats were fed ad libitum for 30 d. The cerebellum was quickly removed and processed for histological and immunohistochemical analysis. Slides were immunostained for glial fibrillary acidic protein (to label Bergmann glia), calbindin (to label Purkinje cells) and NeuN (to label post-mitotic neurons). Microscopic analysis revealed two types of defect: partial disappearance of fissures and/or neuronal ectopia, primarily in supra-supplemented animals (incidence of 80 %, P≤0·01), but also in deficient and supplemented groups (incidence of 40 %, P≤0·05), compared with control animals. The primary fissure was predominantly affected, sometimes accompanied by defects in the secondary fissure. Our findings show that growing rats fed an FA-modified diet, including both deficient and supplemented diets, have an increased risk of disturbances in cerebellar corticogenesis. Defects caused by these diets may have functional consequences in later life. The present study is the first to demonstrate that cerebellar morphological defects can arise from deficient, as well as high, FA levels in the diet.
  • Publication
    Immunocytochemical study on the triple origin of the sphincter iris in the chick embryo
    (Springer-Verlag, 1999-10) Barrio Asensio, María del Carmen; Murillo González, Jorge Alfonso; Peña Melián, Ángel; Puerta Fonollá, Javier
    The ontogenic development of the sphincter iris has been studied by immunocytochemistry and standard staining on chick embryos from stage 25 HH to the time of hatching. We have used the monoclonal antibody 13F4, a highly specific marker of muscular cells. We have observed three different regions in the iris. Tn the pupillary region, immunoreactive cells are in continuous contact with the inner epithelium of the pupillary margin. In the intermediate region, the outer epithelium forms buds of pigmented cells that emigrate toward the stroma. In this epithelium cells that are totally or partially unpigmented exist, and they are 13F4 positive. In the sphincter we have observed 13F4 positive cells with melanin granules. In the ciliary region, the immunoreactivity appears in dispersed mesenchymal cells. The present findings are consistent with a triple origin of the sphincter iris in the chick embryo. This muscle is derived from the inner epithelium of the pupillary margin, the intermediate region of the outer epithelium, and from the mesenchymal cells. The cells of the inner epithelium of the pupillary margin are differentiated into smooth muscle cells, and the remaining cells form striated muscle cells.
  • Publication
    Desarrollo de un espacio web de prácticas de neuroanatomía y embriología humanas
    (Editorial Complutense, 2007) Peña Melián, Ángel; Pérez de Miguelsanz, Julia; Maestro de Las Casas, María del Carmen; Blanco Fernández de Valderrama, María Jose; Cabrera Parra, Walter; Fernández-Valmayor Crespo, Alfredo; Fernández-Pampillón Cesteros, Ana María; Merino Granizo, Jorge
    Presentamos dos proyectos que se relacionan, el primero con la mejora en las prácticas de neuroanatomía para alumnos de segundo de medicina, y el segundo con la enseñanza de la embriología humana, un proyecto bastante complejo del que presentamos aquí su inicio, pero que deseamos convertirlo a medio plazo en una asignatura virtual.