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).

La singularidad de los maxilares dentro del sistema esquelético / Singularity of the jaws within the skeletal system

En la odontología es frecuente que se describa la peculiaridad de los huesos maxilares en cuanto a la resistencia a las infecciones en comparación con otros huesos de la economía. O que se plantée un desafío cuando es necesario tomar una decisión acerca de aplicar diferentes conductas terapéuticas en pacientes con patologías óseas sistémicas. Por ello, esta actualización tuvo como objetivo realizar una revisión de la bibliografía para integrar y evidenciar las diferencias y similitudes entre los diferentes huesos de la economía haciendo hincapié en los huesos maxilares. Si bien éstos poseen una gran cantidad de similitudes con el resto de los huesos, también presentan diferencias que los hacen entidades únicas dentro del sistema esquelético como el origen embriológico en las células de las crestas neurales, su alta tasa de remodelación, sin olvidar que estos huesos alojan a órganos que poseen una parte de su estructura en el medio interno y otra porción en medio externo de la cavidad bucal: las piezas dentarias (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.

Is there a relationship between complaints of impaired balance and postural control disorder in community-dwelling elderly women? A cross-sectional study with the use of posturography

Background: Risk of falls increases as age advances. Complaints of impaired balance are very common in the elderly age group. Objectives: The objective of this study was to investigate whether the subjective perception of impaired balance was associated with deficits in postural control (objective analysis) in elderly community-dwelling women. Method: Static posturography was used in two groups: elderly women with (WC group) and without (NC group) complaints of impaired balance. The area, mean sway amplitude and mean speed of the center of pressure (COP) in the anterior-posterior (AP) and medial-lateral (ML) directions were analyzed in three stances: single-leg stance, double-leg stance and tandem stance, with eyes open or closed on two different surfaces: stable (firm) and unstable (foam). A digital chronometer was activated to measure the time limit (Tlimit) in the single-leg stance. Kruskal-Wallis tests followed by Mann-Whitney tests, Friedman analyses followed by post hoc Wilcoxon tests and Bonferroni corrections, and Spearman statistical tests were used in the data analysis. Differences of p<0.05 were considered statistically significant. Results: The results of posturography variables revealed no differences between groups. The timed single-leg stance test revealed a shorter Tlimit in the left single-leg stance (p=0.01) in WC group compared to NC group. A negative correlation between posturography variables and Tlimit was detected. Conclusions: Posturography did not show any differences between the groups; however, the timed single-leg stance allowed the authors to observe differences in postural control performance between elderly women with and those without complaints of impaired balance. .

Paraganglioma gangliocítico en la tercera porción del duodeno / Gangliocytic paraganglioma in the third portion of the duodenum

El paraganglioma gangliocítico es un tumor neuroendocrino no epitelial, originado de la cresta neural, que afecta en la gran mayoría de los casos la segunda porción del duodeno, sin embargo puede presentarse en cualquiera de sus porciones e inclusive originarse en el yeyuno proximal, en el apéndice y en otros sitios menos frecuentes. Por su localización y la tendencia a ulcerarse, estas lesiones pueden manifestarse por sangrado digestivo, ictericia, obstrucción o anemia como en el caso que describiremos más adelante, y muchas veces son encontradas de forma incidental durante procedimientos endoscópicos o autopsias. El paraganglioma gangliocítico es un tumor benigno de pronóstico favorable, aunque se han reportado algunos casos de recurrencia, invasión linfática o metástasis a distancia. Histológicamente el paraganglioma gangliocítico está compuesto por varios patrones celulares, los cuales pueden ser corroborados mediante inmunohistoquímica y su tratamiento debe ir dirigido a la resección local o radical en algunos casos.

Gangliocytic paraganglioma is a non-epithelial, neuroendocrine tumor that originates from the neural crest. In the majority of cases, it affects the second part of the duodenum, however it may occur in any of its parts and even originate in the proximal jejunum, the appendix and other less frequent places. Because of its location and high tendency to ulcerate, these lesions can appear as gastrointestinal bleeding, jaundice, obstruction and anemia, as in the case described herein. Also, many times they are found incidentally during endoscopy or autopsy. Gangliocytic paraganglioma is a benign tumor, with a favorable prognosis, but some cases of recurrence, lymphatic invasion and metastasis have been reported. Histologically gangliocytic paraganglioma is composed by various cell patterns which can be found by immunohistochemistry and in some cases its treatment consists of radical or local resection.

Células de la cresta neural: Evolución, bases embrionarias y desarrollo cráneo-facial. Revisión sistemática de la literatura / Neural crest cells: Evolution, embryonic bases and craniofacial development. Systematic literature review

Las células de la cresta neural constituyen una población de células embrionarias - pluripotenciales que se diferencian desde el neuro-ectodermo y cuya aparición se constituye en una innovación evolutiva que le permitió a los vertebrados desarrollar una serie de estructuras morfo-funcionales para adaptarse de un estilo de alimentación suspensívora-filtradora a una predadora activa mucho mas eficiente. Esta revisión sistemática de la literatura describe el papel fundamental de las células de la cresta neu - ral en el desarrollo evolutivo y embrionario de las estructuras cráneo-faciales. Con este propósito se realizó una búsqueda en PubMed a través del descriptor en salud (MeSh) "neural crest" combinado con las expresiones "neurulation, evolution, embryonic and fetal development, craniofa - cialdevelopment" a través de los conectores boleanos "AND" y "+". Palabras claves: Neurulación, placa neu- ral, cresta neural, células de la cresta neural, desarrollo embrionario y fetal, desarrollo cráneo-facial.

The neural crest cells are a population of embryonic stem cells that differentiate from the neuro-ectoderm and whose appearance constitutes an evolutionary innovation allowed vertebrates develop different morpho-functional structures to adapt from asuspensivorous eating style to a predatory style, much more efficient. This systematic literature review describes the essential role of neural crest cells in the evolutionary and embryonic development of the craniofa - cial structures of the vertebrates.For this purpose we searched PubMed through the Medical Subject Headings (MeSh) "neural crest" combined with the terms "neurula - tion, evolution, embryonic and fetal develo - pment, craniofacial development" through the Boolean connectors"AND" y "+".

Primitive tumor of lamina fusca: original findings

In a meeting of the Pan-American Association of Ophthalmic Pathology, held in Los Angeles, CA, on October 10, 1991, at the Doheny Eye Institute, C.O. Degrazia proposed the name LOFONEUROGONIOMA for a single undifferentiated intraocular tumor originated in the cells of lamina fusca, with undifferentiated cells of expressive differentiation into Schwann cell, melanoblast and neuroendocrine cell lineages. In view of trimorphism, a pathologist may be led to a diagnosis of malignant melanoma, schwannoma or endocrine cell tumor. After this date, an article was published in Revista da AMRIGS, Porto Alegre, 52 (4): 261-272, oct-dec 2008, with collaboration of experts from the fields of Immunohistochemistry and electron microscopy. The current publication is the third one and its main purpose is to highlight the original characteristics of such a tumor.

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 intraocular, indiferenciado, originado nas células da lâmina fusca, com células indiferenciadas de expressiva diferenciação para a linhagem schwannoblástica, melanoblástica e neuroendócrina. Em face do trimorfismo, o patologista pode ser conduzido para os diagnósticos de melanoma, schwannoma malignos, ou tumor de células endócrinas. Foi feita após essa data uma publicação na Revista da AMRIGS. Porto Alegre, 52 (4): 261-272, out.-dez 2008, na qual consta a lista dos colaboradores. A publicação atual é a terceira, tendo como finalidade principal colocar em relevo as originalidades de semelhante tumor.

Origen y Migración de Células Troncales / Stem Cells Origin and Migration

La generación de progenitores celulares, su migración y distribución a través del organismo, es determinante en la generación de divergencia morfológica y evolución de las distintas especies de vertebrados. Las células progenitoras transitan por diferentes compartimentos durante el desarrollo embrionario y su exposición a diferentes medioambientes tisulares estimula la activación de programas específicos de diferenciación. En este capítulo discutiremos el origen de diferentes poblaciones de células migratorias, tales como las células madre embrionarias, las células germinales primordiales y las células de la cresta neural, con un enfoque en los distintos factores moleculares activados durante la migración hacia distintos compartimientos embrionarios.

Generation, migration and distribution of stem cells throughout the body are a major process in the generation of morphological divergence and evolution in different species of vertebrates. Progenitor cells pass through different compartments during embryonic development and the exposition to different tissue environments stimulates the activation of specific differentiation programs. In this chapter we discuss the origin of different migratory cell populations, such as embryonic stem cells, primordial germ cells and neural crest cells, with focus on the different molecular factors activated during migration to different embryonic compartments.

Desarrollo de Cara y Cuello en Vertebrados / Face and Neck Development in Vertebrates

El desarrollo embrionario de las regiones facial, del cuello, cavidades nasales y oral en conjunto con las glándulas asociadas, involucra el crecimiento y fusión tridimensional de múltiples procesos. Existe participación de elementos derivados de las 3 capas embrionarias locales y adicionalmente de células derivas de la cresta neural, procedentes de los rombómeros vecinos. Estas últimas se ven involucradas en la formación del esqueleto local, entre otras estructuras. El estudio evolutivo desde los vertebrados sin mandíbula nos enseña como se expresan los genes Hox en las diferentes especies, y como esto determina la formación de diferentes estructuras. En la siguiente revisión contemplamos algunos aspectos morfológicos, moleculares y evolutivos básicos del desarrollo facial y cervical, con énfasis en mamíferos con un epílogo referente a las malformaciones de la región en humanos.

The embryonic development of the facial area, neck, nasal, oral and pharyngeal cavities with glands, involves growth and fusion of multi-dimensional processes. There is involvement of elements from the embryo-derived local 3 layers cells further neural crest derived cells from the neighbors rhombomeres. The neural crest cells are involved in the formation of local skeleton, among other structures. The study of evolution from jawless vertebrates shows us how Hox genes are expressed in different species, and how this determines the formation of different structures. The following review contemplate some morphological, molecular and evolutionary basis of facial and neck development, with emphasis on mammals with an epilogue concerning to the face and neck malformations in humans.

Estado del arte tumores de cresta neural, neurblastoma fisiopatología, diagnóóstico y tratamiento / State of art: neuural crest tumors, neuroblastoma (nb) pathophsiology, diagnoosis and treatment / Estado de arte: ttumores de cresta neural, neuroblastoma fisiopatologia, diagnóstico e tratamento

El neuroblastoma es el tumor sólido extracraneal más frecuente en la infancia, con incidencia de 650 casos al año en los Estados Unidos de America y 100 casos por año en Italia y España. Se trata de un tumor que evoluciona de forma variable, desde la regresión espontánea hasta un comportamiento muy maligno, sobre todo en niños en edades mayores y con la existencia de enfermedad diseminada. Los signos y síntomas de presentación del neuroblastoma reflejan la localización del tumor y debido a las múltiples presentaciones clínicas, puede confundirse con gran variedad de patologías. Su tratamiento incluye la cirugía, la quimioterapia, la radioterapia y la terapia inmunológica. El papel de cada uno se determina anticipando el comportamiento clínico del tumor en cada caso, considerando la edad, el estadio y determinados parámetros biológicos. En los últimos 10 años, la estratificación por grupos de riesgo de los pacientes con neuroblastoma, basada en el análisis de un panel amplio de variables clínicas y biológicas, entre las que destacan la edad, el estadio y la amplificación del N-MYC, ha permitido un diagnóstico temprano y nuevas pautas para una mejoría importante en su tratamiento. El tratamiento del neuroblastoma se diseña hoy en día según grupos de riesgo, que se definen por parámetros clínicos y biológicos cada vez más sofisticados. El mejor conocimiento de la biología del neuroblastoma ha permitido distinguir entre aquellos tumores que pueden curarse con un tratamiento mínimo y los que requieren de un tratamiento multidisciplinario y complejo para tener posibilidades de curación. Es fundamental realizar al diagnóstico temprano con indicaciones de estadio y desarrollo de una terapia oportuna.

Neuroblastoma (NB) is the most common extracranial solid cancer in childhood and the most common cancer in infancy, with an annual incidence of about 650 cases per year in the US, and 100 cases per year in Italy and Spain. Roughly 50 percent of neuroblastoma cases occur in children younger than two years of age. It is a neuroendocrine tumor, arising from neural crest cells of the sympathetic nervous system (SNS). It most frequently originates in one of the adrenal glands, but can also develop in nerve tissues located in the neck, chest, abdomen, and pelvis. It is a highly variable tumor that can spontaneously regress or have highly malignant behavior, especially in older children with disseminated disease. Signs and symptoms of neuroblastoma reflect the presentation of tumor location and because of the multiple clinical presentations, can be confused with a variety of pathologies. Treatment modalities include surgery, chemotherapy, radiotherapy and immunotherapy. The role of each method is determined in advance of the clinical behavior of the tumor on a case specific basis, consideration of the age, stage and biological parameters. Over the past decade, stratification of patients with risk factors for neuroblastoma based on the analysis of a large panel of clinical and biological variables, among which are age, stage and N-MYC amplification, has allowed for early diagnosis and the generation of new guidelines for major advancements in treatment. Today, treatment of neuroblastoma has become increasingly sophisticated and is influenced by risk factors as well as clinical and biological parameters. A better understanding of the biology of neuroblastoma has allowed for the differentiation between tumors that can be cured with minimal treatment and those requiring a multidisciplinary and complex approach in order to have a chance of cure. Early diagnosis with staging is essential in the development of an appropriate therapy.

O neuroblastoma é o tumor sólido extra-craneal mais frequente na infância, com incidência de 650 casos por ano nos Estados Unidos da América e 100 casos por ano na Itália e Espanha. Trata-se de um tumor que evolui de forma variável, desde a regressão espontânea até um comportamento muito maligno, sobretudo em crianças com idades maiores e com a existência de doença disseminada. Os sinais e sintomas de apresentação do neuroblastoma refletem a localização do tumor e devido as múltiplas apresentações clínicas, pode ser confundido com uma grande variedade de patologias. Seu tratamento inclui a cirurgia, a quimioterapia, a radioterapia e a terapia imunológica. O papel de cada um é determinado antecipando o comportamento clínico do tumor em cada caso, considerando a idade, o estádio e determinados parâmetros biológicos. Nos últimos 10 anos, a estratificação por grupos de risco dos pacientes com neuroblastoma, baseada na análise de um painel amplo de variáveis clínicas e biológicas, entre as que destacam a idade, o estádio, e a amplificação do N-MYC, permitem um diagnostico precoce e novas pautas para uma melhoria importante no seu tratamento. O tratamento do neuroblastoma é feito hoje em dia de acordo com grupos de risco, que são definidos por parâmetros clínicos e biológicos cada vez mais sofisticados. O melhor conhecimento da biologia do neuroblastoma permitiu distinguir entre os tumores que podem ser curados com um tratamento mínimo e os que requerem um tratamento multidisciplinar e complexo para ter possibilidades de cura. É fundamental realizar o diagnóstico precoce com indicações de estádio e desenvolvimento de uma terapia oportuna.

Evolución y desarrollo facial: perspectiva molecular / Facial evolution and development: from a molecular perspective

El desarrollo facial es uno de los eventos más complejos de la embriogénesis, coordinado por un gran número de moléculas que actúan de manera regulada en diversos estadios del desarrollo. Uno de los eventos tempranos más importantes en la formación facial es la generación y migración de las células de la cresta neural, las cuales son consideradas un grupo celular único en los vertebrados, que aporta información para el establecimiento del patrón facial, gracias a su interacción con otros tejidos, así como nuevos tipos celulares. Una vez las células de la cresta han llegado a su destino en los arcos branquiales y se forman las diferentes prominencias faciales, el desarrollo depende del crecimiento, la ex¬pansión y la fusión de dichas prominencias. En esta revisión se aportan hallazgos recientes relacionados con la base molecular de estos procesos de desarrollo, así como nuevas ideas sobre la evolución de esta región.

Facial development is one of the most complex events of embryogenesis. It is coordinated by a great number of molecules that act in a regulated manner at different stages of de¬velopment. One of the most important early events in facial development is the generation and migration of neural crest cells, which are considered a cell group apparently unique to vertebrates. Neural crest cells give rise to a wide variety of cell types and tissues and serve as a source of patterning information, due to their interaction with other tissues. Once neural crest cells have reached the branchial archs and the facial prominences are formed, development relies on the growth, expansion and fusion of those prominences. This review of literature presents recent findings related to the molecular base of those developmental processes as well as new ideas about the evolution of this anatomical part.

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)

Neurofibromas do complexo aréolo-mamilar: relato de caso / Nipple-areolar complex neurofibromas: case report

Neurofibromas são neoplasias benignas originadas de elementos celulares derivados da crista neural e, geralmente, associados a neurofibromatose. A ocorrência destes tumores no complexo aréolo-mamilar é rara. Os autores apresentam relato de caso de neurofibromatose e neurofibramas do complexo aréole-mamilar e fazem uma revisão da forma de apresentação, diagnóstico e tratamento da doença e desta lesão.

Ganglioneuroma no interior de um névus melanocítico gigante: um mero achado acidental? / Cutaneous ganglioneuroma within giant congenital nevus: mere coincidence?

Ganglioneuromas cutâneos são lesões raramente descritas na literatura médica e, deforma ainda mais especial, em associação com outras lesões. Relatamos o achado de umamassa cervical detectada por exame de ultra-som pré-natal, que regrediu no decorrer dagravidez. Após o nascimento, extensa área pigmentada foi observada na mesma localizaçãoda massa, além de um tumor sólido palpável no seu interior. O diagnóstico diferencialcom outros tumores derivados de células da crista neural é importante, assim como acorrelação entre o névus piloso e o ganglioneuroma cutâneo.

Cutaneous ganglioneuroma have been occasionally reported in the literature. We describea case in which a cervical mass firstly detected by routine prenatal ultrasound examinationregressed throughout the months until delivery. After birth, an extensive area ofpigmentation was found at the same location, with a solid mass was perceptible within.The differential diagnosis between other neural crest tumors should be established, aswell the correlation between congenital nevus and cutaneous ganglioneuroma.

Tumor neuroectodérmico melanocítico da infância (progonoma): relato de caso enfatizando os aspectos tomográficos e revisão da literatura / Melanotic neuroectodermal tumor of infancy (progonoma): a case report emphasizing the computed tomography findings and literature review

O tumor neuroectodérmico melanocítico da infância, também conhecido como progonoma, é uma enfermidade rara, benigna, originária da crista neural e que aparece no primeiro ano de vida, acometendo preferencialmente a maxila. Os autores relatam um caso raro deste tumor na maxila de uma criança de dez meses de idade, dando ênfase aos aspectos diagnósticos na tomografia computadorizada, e fazem uma revisão da literatura.

Melanoma maligno: tipo lentiginoso acral: a propósito de un caso / Malignant melanoma: type acral lentiginous: a purpose of a casE

El melanoma maligno es un tumor maligno de los melanocitos. La mayoría de los melanomas se localizan en la piel y menos frecuentemente en mucosas, pero dado el origen de los melanocitos, derivan de las células de la cresta neural. En etapas tempranas el melanoma es curable, pero una vez que ha hecho metátasis, el pronóstico es malo, con una sobrevida de sólo 6 a 9 meses. Hay cinco diversas formas, pero el caso que se presenta a continuación es del tipo lentiginoco acral, en una paciente femenina de 34 años quién consulta por presentar de 6 meses de evolución aumento de volumen y necrosis de hallux de pie izquierdo, este tipo de tumor afecta por igual a ambos sexos, es frecuente de dedos, pies y mucosas. Aparece como mácula pigmentada con o sin nódulos. Por ello, en vista de que esta patología es poco frecuente decidimos este caso y hacer una revisión detallada de la literatura internacional actual

Extracellular signals, cell interactions and transcription factors involved in the induction of the neural crest cells

The neural crest is induced at the border between the neural plate and the epidermis. A complex set of signals is required for the specification of the crest cells between the epidermis and the neural plate. Here we discuss evidence supporting a model for neural crest induction in which different signals contribute in a sequential order. First, a gradient of bone morphogenic proteins (BMPs) is established in the ectoderm that results in segregation into neural plate, neural folds and epidermis at increasing levels of BMP activity. Thus, the neural folds are induced at a precise threshold concentration of BMP, but this neural fold has an anterior character. In a second step, these anterior neural folds are transformed into prospective neural crest by posteriorizing signals due to fibroblast growth factor, Wnts and retinoic acid. Finally, the induced cells interact to complete neural crest induction by a process that requires Notch/Delta signaling. Once neural crest formation has been induced by this combination of extracellular and intracellular signals, a cascade of transcription factors is activated in these cells that culminates in the ultimate steps of neural crest differentiation (AU)#SP#

The neural crest stem cells: control of neural crest cell fate and plasticity by endothelin-3

How the considerable diversity of neural crest (NC)-derived cell types arises in the vertebrate embryo has long been a key question in developmental biology. The pluripotency and plasticity of differentiation of the NC cell population has been fully documented and it is well-established that environmental cues play an important role in patterning the NC derivatives throughout the body. Over the past decade, in vivo and in vitro cellular approaches have unravelled the differentiation potentialities of single NC cells and led to the discovery of NC stem cells. Although it is clear that the final fate of individual cells is in agreement with their final position within the embryo, it has to be stressed that the NC cells that reach target sites are pluripotent and further restrictions occur only late in development. It is therefore a heterogenous collection of cells that is submitted to local environmental signals in the various NC-derived structures. Several factors were thus identified which favor the development of subsets of NC-derived cells in vitro. Moreover, the strategy of gene targeting in mouse has led at identifying new molecules able to control one or several aspects of NC cell differentiation in vivo. Endothelin peptides (and endothelin receptors) are among those. The conjunction of recent data obtained in mouse and avian embryos and reviewed here contributes to a better understanding of the action of the endothelin signaling pathway in the emergence and stability of NC-derived cell phenotypes

Neurocristopatia no diagnóstico diferencial das apnéias do recém nascido: relato de caso / Neurochristopathy in the differential diagnosis of newborn's apnea: case report

OBJETIVO: incluir a neurocristopatia na investigaçäo etiológica das apnéias refratárias do recém nascido e discutir o valor diagnóstico da polissonografia. MÉTODO: relato de caso e discussäo crítica da literatura. RESULTADOS: relatamos o caso de um recém-nascido que apresentou disfunçäo ventilatória nas primeiras horas de vida associada a distensäo abdominal, necessitando de ventilaçäo mecânica contínua com piora do quadro respiratório durante o sono. Após o diagnóstico polissonográfico de hipoventilaçäo foi investigado com exames de neuroimagem e biópsia de cólon, positiva para doença de Hirschprung. CONCLUSÄO: a neurocristopatia é uma síndrome neonatal que por vezes pode ter o seu reconhecimento dificultado pelo amplo espectro clínico associado. A polissonografia foi fundamental nesta investigaçäo confirmando a hipoventilaçäo. Este diagnóstico etiológico deve ser considerado na investigaçäo de recém-nascidos com apnéias persistentes durante o sono

Transformación epitelio mesenquimática durante el desarrollo embrionario / Epithelial mesenchymal transformation during embryonic development

La transformación entre un epitelio y un mesénquima es un proceso celular crítico que cumple una importante función en la morfogénesis de diferentes órganos, como la desaparición del epitelio palatino medio que permite la fusión del paladar; el epitelio del conducto de Müller que está destinado a desaparecer en el macho; la formación del mesoderma durante la gastrulación; el desarrollo de la cresta neural; la formación de las válvulas y tabiques que dividen el corazón embrionario, etc. Durante este proceso, las células epiteliales pierden sus uniones celulares, dejan de expresar citoqueratinas y empiezan a sintetizar vimentina. Además, degradan la lámina basal y extienden filopodios a través de ella hacia el mesénquima subyacente, adoptando una morfología de fibroblasto. El control molecular de este proceso está asociado a factores de crecimiento, especialmente TGF-ß3 y a la proteína zinc finger Slug