ABSTRACT
RESUMEN Las células de la cresta neural son pluripotenciales y son llamadas la cuarta hoja germinativa del embrión. Con el objetivo de estructurar los referentes teóricos actualizados que sustenten la afirmación precedente y que constituirá material de estudio para los estudiantes de las Ciencias Médicas, se realizó la revisión de 28 referencias bibliográficas, de ellas 89% actualizadas. Estas células aparecen durante la neurulación y pasado este proceso transitan de epitelial a mesenquimatosa; migran siguiendo señales de la matriz extracelular a todo el cuerpo del embrión diferenciándose en tejidos disimiles. Muy vinculados en su evolución a mecanismos epigenéticos, hacen a esta población celular vulnerables a ser dañadas invocándose en la etiología de diferentes defectos congénitos y enfermedades crónicas no trasmisibles como cáncer. Como conclusión por su pluripotencialidad y por los mecanismos moleculares que distinguen su evolución son consideradas por muchos autores la cuarta hoja germinativa del embrión (AU).
SUMMARY Neural crest cells are pluripotentials, and are called the fourth germinative leaf of the embryo. With the objective of structuring the updated theoretical referents backing up the precedent affirmation that will be study material for the students of Medical Sciences, the authors reviewed 28 bibliographic references, 89 % of them updated. These cells appear during neurulation and after this process they transit from epithelial to mesenchymal; following extracellular matrix signals, they migrate to the whole embryo body differentiating themselves in dissimilar tissues. Tightly related in their evolution to epigenetic mechanisms, this cell population is very likely to be damaged and so they are invoked in the etiology of different congenital defects and noncommunicable chronic diseases like cancer. In conclusion, due to their pluripotentiality and the molecular mechanisms distinguishing their evolution, many authors consider them the embryo´s fourth germinative leaf (AU).
Subject(s)
Humans , Male , Female , Cells/metabolism , Neural Crest/pathology , Students, Medical , Vertebrates/genetics , Neurulation/physiology , Neural Crest/abnormalities , Neural Crest/physiology , Neural Crest/physiopathologyABSTRACT
Introducción: el Síndrome Neurocutáneo es el término general que se utiliza para referirse a determinados trastornos neurológicos. Constituye un grupo heterogéneo de desórdenes congénitos que afectan principalmente a las estructuras derivadas del neuroectodermo embrionario. Objetivo: caracterizar los hallazgos clínicos de los Síndromes Neurocutáneos identificables al examen físico por el Médico General Integral. Métodos: se realizó un trabajo de revisión donde se utilizaron métodos teóricos en el proceso de revisión de la bibliografía actualizada seleccionada, específicamente en el campo de la neurología, la dermatología y la genética. Resultados: las características clínicas de la Esclerosis Tuberosa, Neurofibromatosis Tipo 1, Tipo 2, Schwannomatosis y Enfermedad de Sturge-Weber (Sindromes Neurocutáneos) se pueden identificar durante el examen físico. Conclusiones: el adecuado conocimiento por el Médico General Integral, de las características clínicas del síndrome neurocutáneo, considerando su heterogeneidad y expresividad clínica, permite realizar al examen físico el diagnóstico oportuno de la enfermedad, lo que favorece el manejo del paciente...
Introduction: the neurocutaneous syndrome is the general term used to refer to certain neurological disorders. It is a heterogeneous group of congenital disorders that primarily affect structures derived from the embryonic neuroectoderm. Objectives: to characterize the clinical features of neurocutaneous syndromes that are identifiable at physical examination by the general comprehensive physician. Methods: a review of the selected current literature was performed for theoretical methods, specifically, in the field of neurology, dermatology and genetics. Results: the clinical characteristics of tuberous sclerosis, types 1and 2 neurofibromatosis, Schwannomatosis and Sturge-Weber disease (Neurocutaneous Syndromes) can be identified during the physical examination. Conclusions: knowledge of clinical features of the neurocutaneous syndrome, considering its clinical heterogeneity and expressiveness, physical examination allows early diagnosis of the disease by general comprehensive physician. This knowledge favors patient management...
Subject(s)
Humans , Male , Female , Health Knowledge, Attitudes, Practice , Physicians, Family , Neurocutaneous Syndromes/diagnosis , Neurocutaneous Syndromes/epidemiologyABSTRACT
The authors examined a case of Bednar tumor(pigmented dermatofibrosarcoma protuberans). A 35-year-old woman presented with protruding black back mass 3x2.5 cm in surface dimension and 1 cm in heigh, which has grown slowly for 30 years. Microscopically the lesion is characterized by spindle cells arranged in storiform pattern and admixed with melanin containing dendritic cells. Ultrastructural study revealed three cell populations: (1) cells resembling fibroblasts, (2) cells resembling perineural cells, and (3) melanocytes. The immunohistochemical study using S-100 protein alpha-1 antitrypsin, antichymotrypsin and EMA revealed negative reaction in spindle fibroblastic tumor cells. The histogenesis of this neoplasm remains controversial; neuroectoderm, perineural cell, fibroblast and histiocyte. Through the ultrastructural study and immunohistochemical study, the authors suggested that Bedner tumor arises form the neuroectoderm with bidirectional to perineural and fibroblastic differentiation.