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PURPOSE: One of the most common malformations of the central nervous system is related to embryonic neural tube alterations. We hypothesized that anencephaly affects the development of the vagina during the human second trimester of pregnancy. Our study compared the biometric parameters of the vagina in human female fetuses with neural tube defects. METHODS: In our study, 34 female fetuses were analyzed, 22 normal and 12 anencephalic, aged between 12 and 22 weeks post conception (WPC). After dissection of the pelvis and individualization of the genital tract, we evaluated the length and width of the vagina using the Image J software. We compared the means statistically using the Wilcoxon-Mann-Whitney test and performed linear regression. RESULTS: We do not identify statistical significance between the groups for the measurements of vaginal length (Control 3.12-18.33 mm/mean = 9.08 mm/SD +  - 3.77 vs. Anencephalic 2.91-13.10 mm/mean = 7.24 mm/SD +  - 2.28, p = 0.3469) and vaginal width (Control 1.04-4.86 mm/mean = 2.71 mm/SD + - 0.94 vs. Anencephalic 1.35-3.17 mm/mean = 2.13 mm/SD + - 0.65; p = 0.2503). The linear regression analysis indicated that 78.57% significance was found in the correlations in normocephalic fetuses and 57.14% significance in anencephalic fetuses (12.3-18.6 WPC). CONCLUSIONS: We do not find differences in the length and width of the vagina in anencephalic fetuses but the vaginal length and width shows a lesser tendency of growth in the anencephalic fetuses during the second trimester suggesting that anencephaly can impact the development of the vagina.

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The internalization of multi-cellular tissues is a key morphogenetic process during animal development and organ formation. A good example of this is the initial stages of vertebrate central nervous system formation whereby a transient embryonic structure called the neural plate is able to undergo collective cell rearrangements within the dorsal midline. Despite the fact that defects in neural plate midline internalization may result in a series of severe clinical conditions, such as spina bifida and anencephaly, the biochemical and biomechanical details of this process remain only partially characterized. Here we review the main cellular and molecular mechanisms underlying midline cell and tissue internalization during vertebrate neural tube formation. We discuss the contribution of collective cell mechanisms including convergence and extension, as well as apical constriction facilitating midline neural plate shaping. Furthermore, we summarize recent studies that shed light on how the interplay of signaling pathways and cell biomechanics modulate neural plate internalization. In addition, we discuss how adhesion-dependent cell-cell contact appears to be a critical component during midline cell convergence and surface cell contraction via cell-cell mechanical coupling. We envision that more detailed high-resolution quantitative data at both cell and tissue levels will be required to properly model the mechanisms of vertebrate neural plate internalization with the hope of preventing human neural tube defects.

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BACKGROUND: The high-density lipoprotein receptor SR-B1 mediates cellular uptake of several lipid species, including cholesterol and vitamin E. During early mouse development, SR-B1 is located in the maternal-fetal interface, where it facilitates vitamin E transport towards the embryo. Consequently, mouse embryos lacking SR-B1 are vitamin E-deficient, and around half of them fail to close the neural tube and show cephalic neural tube defects (NTD). Here, we used transcriptomic profiling to identify the molecular determinants of this phenotypic difference between SR-B1 deficient embryos with normal morphology or with NTD. RESULTS: We used RNA-Seq to compare the transcriptomic profile of three groups of embryos retrieved from SR-B1 heterozygous intercrosses: wild-type E9.5 embryos (WT), embryos lacking SR-B1 that are morphologically normal, without NTD (KO-N) and SR-B1 deficient embryos with this defect (KO-NTD). We identified over 1000 differentially expressed genes: down-regulated genes in KO-NTD embryos were enriched for functions associated to neural development, while up-regulated genes in KO-NTD embryos were enriched for functions related to lipid metabolism. Feeding pregnant dams a vitamin E-enriched diet, which prevents NTD in SR-B1 KO embryos, resulted in mRNA levels for those differentially expressed genes that were more similar to KO-N than to KO-NTD embryos. We used gene regulatory network analysis to identify putative transcriptional regulators driving the different embryonic expression profiles, and identified a regulatory circuit controlled by the androgen receptor that may contribute to this dichotomous expression profile in SR-B1 embryos. Supporting this possibility, the expression level of the androgen receptor correlated strongly with the expression of several genes involved in neural development and lipid metabolism. CONCLUSIONS: Our analysis shows that normal and defective embryos lacking SR-B1 have divergent expression profiles, explained by a defined set of transcription factors that may explain their divergent phenotype. We propose that distinct expression profiles may be relevant during early development to support embryonic nutrition and neural tube closure.

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SR-BI is the main receptor for high density lipoproteins (HDL) and mediates the bidirectional transport of lipids, such as cholesterol and vitamin E, between these particles and cells. During early development, SR-BI is expressed in extraembryonic tissue, specifically in trophoblast giant cells in the parietal yolk sac. We previously showed that approximately 50% of SR-BI-/- embryos fail to close the anterior neural tube and develop exencephaly, a perinatal lethal condition. Here, we evaluated the role of SR-BI in embryonic vitamin E uptake during murine neural tube closure. Our results showed that SR-BI-/- embryos had a very low vitamin E content in comparison to SR-BI+/+ embryos. Whereas SR-BI-/- embryos with closed neural tubes (nSR-BI-/-) had high levels of reactive oxygen species (ROS), intermediate ROS levels between SR-BI+/+ and nSR-BI-/- embryos were detected in SR-BI-/- with NTD (NTD SR-BI-/-). Reduced expression of Pax3, Alx1 and Alx3 genes was found in NTD SR-BI-/- embryos. Maternal α-tocopherol dietary supplementation prevented NTD almost completely (from 54% to 2%, p < 0.001) in SR-BI-/- embryos and normalized ROS and gene expression levels. In sum, our results suggest the involvement of SR-BI in the maternal provision of embryonic vitamin E to the mouse embryo during neural tube closure.

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The development of a vertebrate neural epithelium with well-organized apico-basal polarity and a central lumen is essential for its proper function. However, how this polarity is established during embryonic development and the potential influence of surrounding signals and tissues on such organization has remained less understood. In recent years the combined superior transparency and genetics of the zebrafish embryo has allowed for in vivo visualization and quantification of the cellular and molecular dynamics that govern neural tube structure. Here, we discuss recent studies revealing how co-ordinated cell-cell interactions coupled with adjacent tissue dynamics are critical to regulate final neural tissue architecture. Furthermore, new findings show how the spatial regulation and timing of orientated cell division is key in defining precise lumen formation at the tissue midline. In addition, we compare zebrafish neurulation with that of amniotes and amphibians in an attempt to understand the conserved cellular mechanisms driving neurulation and resolve the apparent differences among animals. Zebrafish neurulation not only offers fundamental insights into early vertebrate brain development but also the opportunity to explore in vivo cell and tissue dynamics during complex three-dimensional animal morphogenesis.

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El síndrome de Wiskott-Aldrich es una inmunodeficiencia primaria; con una incidencia de 3,5 a 5,2 por cada millón de recién nacidos masculinos. Se caracteriza por tener un patrón de herencia recesiva ligada al cromosoma X. En estos pacientes; se ha descrito la tríada clásica de inmunodeficiencia; microtrombocitopenia y eczema. Presentamos un paciente de 5 años de edad; hispánico; con antecedentes de numerosas infecciones desde el primer año de vida. Actualmente; presenta desnutrición crónica; talla baja secundaria y retraso en el desarrollo del lenguaje. Se diagnosticó una mutación poco frecuente del gen asociado al síndrome de Wiskott-Aldrich.

The Wiskott-Aldrich syndrome is a rare X-linked recessive immunodeficiency, with an estimated incidence of 3.5 to 5.2 cases per million males. It is characterizedby immunodeficiency, microthrombocytopenia and eczema. We present a 5-year-old Hispanic male, with a medical history of numerous infectious diseases, compromised health, chronic malnutrition, language delay and failure to thrive. An infrequent mutation in the Wiskott-Aldrich syndrome gene was found.

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El síndrome de Wiskott-Aldrich es una inmunodeficiencia primaria; con una incidencia de 3,5 a 5,2 por cada millón de recién nacidos masculinos. Se caracteriza por tener un patrón de herencia recesiva ligada al cromosoma X. En estos pacientes; se ha descrito la tríada clásica de inmunodeficiencia; microtrombocitopenia y eczema. Presentamos un paciente de 5 años de edad; hispánico; con antecedentes de numerosas infecciones desde el primer año de vida. Actualmente; presenta desnutrición crónica; talla baja secundaria y retraso en el desarrollo del lenguaje. Se diagnosticó una mutación poco frecuente del gen asociado al síndrome de Wiskott-Aldrich.(AU)

The Wiskott-Aldrich syndrome is a rare X-linked recessive immunodeficiency, with an estimated incidence of 3.5 to 5.2 cases per million males. It is characterizedby immunodeficiency, microthrombocytopenia and eczema. We present a 5-year-old Hispanic male, with a medical history of numerous infectious diseases, compromised health, chronic malnutrition, language delay and failure to thrive. An infrequent mutation in the Wiskott-Aldrich syndrome gene was found.(AU)

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BACKGROUND: The peripheral olfactory sensory system arises from morphologically identifiable structures called placodes. Placodes are relatively late developing structures, evident only well after the initiation of somitogenesis. Placodes are generally described as being induced from the ectoderm suggesting that their development is separate from the coordinated cell movements generating the central nervous system. RESULTS: With the advent of modern techniques it is possible to follow the development of the neurectoderm giving rise to the anterior neural tube, including the olfactory placodes. The cell movements giving rise to the optic cup are coordinated with those generating the olfactory placodes and adjacent telencephalon. The formation of the basal lamina separating the placode from the neural tube is coincident with the anterior migration of cranial neural crest. CONCLUSIONS: Olfactory placodes are transient morphological structures arising from a continuous sheet of neurectoderm that gives rise to the peripheral and central nervous system. This field of cells is specified at the end of gastrulation and not secondarily induced from ectoderm. The separation of olfactory placodes and telencephalon occurs through complex cell movements within the developing neural plate similar to that observed for the developing optic cup.

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Durante el desarrollo embrionario, las células de muchos tejidos se diferencian de acuerdo con la información de posición que se establece por las gradientes de concentración de morfógenos. Estas son moléculas de señalización secretadas en una región restringida de un tejido y se difunden lejos de su fuente para formar una gradiente de concentración. La molécula de un mismo morfógeno actúa generalmente en distintas etapas de desarrollo de un organismo y puede provocar reacciones muy diferentes en las células en función de su historia de diferenciación. Los morfógenos más conocidos son miembros del factor de crecimiento beta (TGF-b), Hedgehog (Hh), familias Wnt y los microRNAs.

During embryonic development, cells in many tissues differ according to the positional information that is set by the concentration of morphogen gradients. These are signaling molecules that are secreted in a restricted region of a tissue and diffuse away from their source forming a concentration gradient. Morphogens generally act at different development stages in an organism and cause different reactions in cells depending on their history of differentiation. The best known example of morphogens are members of growth factor beta (TGF-beta), Hedgehog(Hh), and Wnt families or microRNAs.

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En la presente revisión bibliográfica se hace referencia del ácido fólico, vitamina perteneciente al complejo B,cuya ingestión en etapa preconcepcional contribuye a la prevención de defectos congénitos y otros problemas relacionados con la salud del ser humano. El Ácido Fólico (AF) es necesario para la formación de proteínas estructurales y hemoglobina. La deficiencia de AF es la condición en que cuerpo carece de reservas adecuadas de vitamina B9. Durante toda la gestación se debe ingerir AF, debido al continuo proceso de crecimiento y desarrollo del embrión y feto, donde el AF participa en la metilación del ADN, proceso imprescindible para la constante división y crecimiento celular. El cierre de neuroporos del tubo neural ocurre antes que finalice el primer mes de embarazo. Cuando la mujer se da cuenta que está embarazada, las consecuencias de una dieta deficiente en AF ya habrán mostrado sus consecuencias, provocando varias deformaciones congénitas denominadas malformaciones por Defectos de cierre del Tubo Neural (DTN). La ingesta de AF debe recomendarse en toda la vida reproductiva de la mujer (pubertad-antes de menopausia), esto evita el aumento de la homocisteína; productor importante de DTN...

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