Cresta neural, cuarta hoja, germinativa embrionaria / Neural crest, fourth embryonary germinative leaf

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).

Células de la cresta neural y su relación con cardiopatía congénita: revisión sistemática de la literatura / Neural crest cells and their relation to congenital heart disease: systematic review of the literature

Las cardiopatías congénitas corresponden al grupo de anomalías del desarrollo que se presentan con mayor frecuencia. Durante el desarrollo cardíaco participan distintos linajes celulares, donde destacan las Células de la Cresta Neural (CCN) por su amplia gama de derivados embriológicos y la susceptibilidad de afectar a múltiples sistemas si su función es alterada. El objetivo fue determinar el rol que cumplen las CCN durante el desarrollo cardíaco y las cardiopatías congénitas asociadas. Se diseñó un estudio descriptivo en base a una revisión sistemática de la literatura de las bases de datos MEDLINE y Scopus, utilizando la combinación de términos MeSH: ("Heart Diseases/congenital" OR "Heart Diseases/embriology" OR "Heart Diseases/etiology" OR "Heart Disesaes/epidemiology") AND ("Neural Crest/abnormalities"). Se restringió la búsqueda a artículos de los últimos 10 años. De un total de 35 artículos obtenidos, 22 fueron incluidos para su revisión por estar relacionados con los objetivos de este estudio, excluyéndose duplicados entre bases de datos. Posteriormente se hizo un análisis individual y en conjunto de la información obtenida de los artículos seleccionados. La evidencia indica la participación directa o indirecta de las CCN durante la formación de las estructuras derivadas del polo arterioso del corazón en desarrollo, los grandes vasos arteriales y sus ramas colaterales, así como en su inervación y sistema de conducción. La alteración del funcionamiento normal de las CCN produce fenotipos cardíacos alterados, siendo la persistencia del tronco arterioso, doble salida ventricular derecha, defectos septales interventriculares y malformación de los aparatos valvares aórtico y pulmonar, los más frecuentes.

Congenital heart defects are the group of most frequent anomalies of development. Cardiac development in different cell lines, which include the Neural crest cells (NCC) for their wide range of embryological derivatives and susceptibility to affect multiple systems if their function is altered participate. The objective was to determine the role of the NCC during heart development and associated congenital heart disease. A descriptive study was designed based on a systematic review of the literature from the MEDLINE and Scopus data, using a combination of MeSH terms ("Heart Diseases / congenital" OR "Heart Diseases / Embryology" OR "Heart Diseases/etiology "OR" Heart Diseases/epidemiology ") AND ("Neural Crest/abnormalities"). Search for articles in the last 10 years was restricted. From a total of 35 articles retrieved, 22 were included related to the objectives of this study for review, excluding duplicated between databases. Subsequently, an individual and joint analysis was realized with the information from the selected items. Evidence indicates the direct or indirect involvement of NCC during the formation of the structures derived from arterial pole of the developing heart, the large arterial vessels and their collateral branches, as well as its innervation and conduction system. The disruption of normal operation of the NCC produces altered cardiac phenotypes, with the Persistence Truncus Arteriosus, Double-Outlet Right Ventricle, ventricular Septal Defects and malformation of the most common valvular aortic and pulmonary devices.

Tumor indiferenciado da lâmina fusca / Undifferentiated tumor of the lamina fusca

Na reunião da Associação Pan-americana de Patologia Oftálmica, realizada em Los Angeles CA, 10 de Outubro de 1991, no DOHENY EYE INSTITUTE, C.O. Degrazia propôs o nome de LOFONEUROGONIOMA para um tumor solitário intra-ocular, indiferenciado, originado nas células da lâmina fusca, com células indiferenciadas de expressiva diferenciação para a linhagem schwannocítica, melanocítica e neuroendócrina. Em face do trimorfismo, o patologista pode ser conduzido para os diagnósticos de melanoma, schwannoma maligno ou outro tipo de tumor. O exaustivo estudo do tumor apresentado, através da microscopia eletrônica, da histoquímica e da imunohistoquímica permitiu a formulação da seguinte hipótese: uma célula indiferenciada em repouso, a lofoneurogô- nia, segue as linhagens melanocítica, schwannocítica e neuroendócrina. A diversidade de células dentro de um tumor, o continuus intratumor, responsável pela estrutura em mosaico de muitas neoplasias, além da multiclonalidade resultante de mitoses atípicas, pode ser explicada por essa hipótese. É dessa maneira que se torna compreensível a classificação de Callender para os melanomas intra-oculares nos tipos celulares fusiforme A, fusiforme B, epitelióide, fasciculado e misto, num verdadeiro continuus intertumores. Para justificar a designação proposta, e para enquadrar o caso num grupo taxonômico, foram usadas duas bases classificatórias: 1o ­ histogênica, isto é, correlacionar as células do tumor com as células normalmente existentes nas membranas oculares, no caso, a lâmina fusca; 2o ­ embriogênica isto é, delimitar um grupo de tumores cuja base, no desenvolvimento do embrião, é a crista neural (AU)

In the meeting of the Panamerican Association of Ophtalmic Pathology, held in the Doheny Eye Institute in Los Angeles, CA on Oct 10 1991, C.O. Degrazia proposed the name LOPHONEUROGONIOMA for an undifferentiated intraocular solitary tumor, originating from the cells of the lamina fusca, with undifferentiated cells of expressive differentiation for the schwannian, melanocitic and neuroendocrine lines. Because of the trimorphism, the pathologist may be led to the diagnosis of melanoma, malignant schwannoma or other type of tumor. The exhaustive investigation of the presented tumor through electronmicroscopy, histochemistry, and immunohistochemistry allowed the formulation of the following hypothesis: an undifferentiated cell at rest, the lophoneurogonia, follows the melanocitic, schwannian, and neuroendocrine lines. The diversity of cells inside a tumor responsible for the mosaic structure of many neoplasias, besides the multiclonality resulting from atypical mitoses, can be explained by this hypothesis. This also elucidates Callender's classification of intraocular melanomas in cell types fusiform A, fusiform B, epithelioid, fasciculated and mixed, in a true intertumor continuum. In order to justify the proposed designation, and to fit the case into a taxonomic group, two classificatory bases were used: first, a histogenic one, correlating tumor cells with normally existing cells; and second, embriogenic which bases is the neural crest (AU)

Associated developmental anomalies of the anterior end of the neural crest: Hirschprung's disease/Waadrenburg syndrome

Three patients are described in whom Hirschsprung's disease was associated, in varying degree, with deafness, disturbance of facial configuration and deficient pigmentation of the skin and its appendages; expressing developmental defects of the anterior end of the neural crest. The anomalies described are seen, not as separate and fortuitously associated lesions, but rather as different aspects of a single developmental disturbance of the anterior end of the neural crest. In sporadic reports[14-17] [as shown in text] a substantial experience of such patients is recorded, though texts on pediatric surgery rarely quote this