Mémoire sur les ville et tour de Crest

Ancien possesseur : Argenson, Antoine-René de Voyer (1722-1787 ; marquis de Paulmy d')

Dragon (Jean). Album des amis de Jean Dragon, professeur à l'académie de Die et pasteur de Crest.

Il contient des inscriptions et des signatures recueillies entre les années 1599 et 1615 à Genève et dans le Dauphiné. On y remarque celles qui émanent des personnages suivants : " Is. Casaubonus (fol. 17), Theodorus Beza (fol. 112), Joannes Vulso Columberius (fol. 142), Joannes Leslaeus a Crychy Scotus (fol. 144), Jacobus Goulartius Genevensis (fol. 175), Johannes Goulartius Genevensis (fol. 175 v°). " Petit volume de 181 feuillets, hauts de 153 millimètres et larges de 98. On a fait servir à la composition de cet album : 1° 96 feuillets appartenant à douze cahiers signés A-M, ornés d'encadrements variés et sur les rectos desquels avaient été imprimés les médaillons de personnages célèbres, et des devises en grec, en latin, en allemand, en français, en italien et en espagnol ; 2° 85 feuillets à encadrements variés.

Virus del sindrome de Taura (STV), y virus del sindrome de la mancha blanca (WSSV), agentes causantes de Epizootias en la camaronicultura mexicana ( 1996-1999)

[Tesis] ( Doctor en Ciencias con Especialidad en Biología) U.A.N.L.

Caracterización de las alteraciones en la función renal, la presión arterial y las malformaciones anatómicas renales- urinarias y cardiovasculares en pacientes con Sindrome de Turner en la Fundación Cardioinfantil entre 1999 y 2009

Se caracterizan las malformaciones renales y urinarias (MRU), y cardiovasculares (CV), así como la función renal (FR) y la presión arterial (PA) en pacientes con Sindrome de Turner (ST) mediante un estudio retrospectivo entre 1999 y 2009 en Bogotá. Se encontró 10 pacientes con algún grado de insuficiencia renal crónica (IRC). Además 4 pacientes presentaron prehipertensión arterial, y 5 (HTA); en ellos se encontró hidronefrosis y riñón poliquístico. Las MRU más frecuentes fueron únicas; en ellas las mayores alteraciones cromosómicas son la monosomía y el mosaicismo. La mayor malformación CV fué la válvula aórtica bicúspide. El ST amerita seguimiento de FR y PA para prevenir complicaciones a largo plazo por IRC e HTA.

Sindrome de burnout y factores asociados en personal de salud de tres instituciones de Bogotá en diciembre de 2010

Introducción: El síndrome de burnout (SB) ha tomado relevancia clínica y social a nivel mundial, estudiado bajo variadas metodologías con resultados no comparables, con algunas aproximaciones en Colombia, que justifican profundizar su conocimiento en el contexto de Bogotá. Metodología: Estudio de corte transversal, con el objetivo de identificar la prevalencia de SB, dimensiones que lo componen y factores asociados. Se utilizó cuestionario de variables socio demográficas y cuestionario Maslach Burnout Inventory (MBI), con análisis descriptivo, bivariado y multivariado en SPSS. Resultados: Se encuestaron 184 trabajadores de la salud -médicos, enfermeras y personal auxiliar-, 139 mujeres (75,5%) y 45 hombres (24,5%), con una prevalencia del 2,2% para SB. En modelo de regresión logística multinomial se encontró asociación significativa (p<0.05) para baja realización personal y despersonalización. Prevalencia para agotamiento emocional 20,6%, despersonalización 16,8% y baja realización personal 7,6%. Discusión: La comparación de los resultados es compleja de acuerdo a las diferentes escalas de mediciones utilizadas en otros estudios. Es importante resaltar el papel protagónico del las mujeres en la muestra, lo cual puede influir en la presentación del burnout bajo la perspectiva de la ambigüedad de roles. Conclusiones: Una prevalencia del 2,2% para síndrome de burnout, niveles de agotamiento emocional y despersonalización de 20,6% y 16,8% en el grupo estudiado hacen preciso profundizar el estudio, con inclusión de factores transculturales y características particulares relacionadas con el oficio del personal de salud en grandes ciudades, que puede afectarse con variables del entorno que generan estrés y pueden influir en la presentación del síndrome.

Trombosis venosa obstetrica no neurologica en Lupus y Sindrome Antifosfolipido

El Lupus Eritematoso Sistémico y Síndrome Antifosfolípido son condiciones que asociadas al embarazo aumentan el riesgo de eventos trombóticos, hasta en un 40%. Metodología: Se realizó una revisión sistemática de literatura para identificar la mejor evidencia relacionada con eventos trombóticos obstétricos no neurológicos en un periodo de 10 años; con lectura crítica de la totalidad de artículos encontrados. Resultados: Se encontraron un total de 1340 artículos, de los cuales 7 y 14 artículos respectivamente para LES y SAAF cumplieron criterios para su selección. La evidencia fue en su mayoría nivel III. El LES muestra una tendencia como factor de riesgo para ETV (OR 8,05 IC95% 0,23 – 276), al igual que el SAAF pero con mayor peso estadístico (OR 23.9 IC95% 5,12- 111). Discusión: No se encuentra evidencia en la literatura que caracterice integralmente los eventos trombóticos venosos en las pacientes obstétricas con SAAF y LES. Las gestantes con SAAF presentan mayor riesgo para eventos trombóticosque las pacientes con LES pese a ser mayor que en la población general. Esta tendencia se asoció con AAF altos positivos, triple positividad para AAF, ANA- positivo y LES asociado a SAAF, con resultados marcados durante el puerperio, e influencia en resultados obstétricos relacionada con variables inmunológicas (títulos AAF altos positivos y positividad para ACL, AL, B2GP), edad y antecedentes trombóticos. Conclusión: Existe mayor riesgo de presentar ETV en pacientes obstétricas con SAAF más que con LES, con una tendencia protrombóticasignificativa en el puerperio.

Sindrome de Rett

Neste Projecto de Investigação proponho abordar questões relacionadas com o Síndrome de Rett, pois é uma temática pouco estudada e consequentemente, a bibliografia é escassa. Tendo um grande interesse pela Deficiência Mental e sabendo que há muitas coisas, e algumas muito boas, pretendo com este estudo saber mais acerca das necessidades e das competências da criança com Síndrome de Rett. A experiência profissional, por opção própria e consciente, relaciona-se com crianças portadoras de deficiências. Os profissionais que trabalham nesta área gostam do que fazem, do qual os professores de Ensino Especial e, por isso, há o intuito de ter possibilidades em compreender todas as vontades e desejos, alegrias e tristezas, conforto e desconforto que as nossas crianças nos comunicam, muitas vezes com um simples olhar. Sabemos que podemos trabalhar juntos, de mãos dadas, para que isso aconteça, como dizia Carl Sandburg: "Enquanto há vida, há esperança". É emocionante quando nos encontramos a caminho de novas descobertas que nos tragam respostas às nossas questões e à esperança de tratamentos que ajudarão as crianças com Síndrome de Rett. Nas palavras de Eleanor Roosevelt, “nunca duvide que o comprometimento de um pequeno grupo de pessoas dedicadas possa mudar o mundo. Na verdade é a única coisa que pode”. Flocos de neve são uma das coisas mais frágeis da natureza... mas veja só o que eles podem fazer quando se juntam! Por outro lado pretende-se planear Programas de Intervenção apropriados. Com base nestes pressupostos aceitei o desafio e encaro o tema pelo que tem de novidade e, aprofundar os conhecimentos na área da deficiência mental. O Projecto encontra-se organizado em duas partes. Na primeira parte, proceder-se-á à análise da literatura onde se fará a apresentação da problemática e dos conceitos fundamentais do trabalho. Tentar-se-á fazer uma abordagem a vários aspectos que se consideram de grande importância para a compreensão desta deficiência. Assim, nesta parte I caracterizar-se-á o Síndrome de Rett, analisar-se-ão as suas causas, o diagnóstico e medidas de intervenção médica, terapêutica, educativa, pedagógica, psicológica e social. Parte II, apresentar-se-á o objecto de estudo, de acordo com a pergunta de partida. Especificar-se-ão as hipóteses teóricas que estão na base desta pesquisa e as respectivas variáveis dependentes e independentes que visarão estabelecer elos de ligação causa e efeito. Apresentar-se-á os instrumentos de pesquisa e os aspectos metodológicos respeitantes ao estudo de uma criança com Síndrome de Rett sobre a qual serão colhidos dados para a elaboração deste trabalho. Surgem as considerações finais e conclusão onde se colocarão questões e pistas sobre a importância do conhecimento das dificuldades e competências adquiridas pela criança para a elaboração de um Projecto de Intervenção. Faz-se também referência à bibliografia consultada para recolha de dados necessários à realização deste estudo. Os anexos constarão de um glossário.

The role of Wnt signalling in the development of somites and neural crest

The Wnt family of secreted signalling molecules controls a wide range of developmental processes in all metazoans. In this investigation we concentrate on the role that members of this family play during the development of (1) the somites and (2) the neural crest. (3) We also isolate a novel component of the Wnt signalling pathway called Naked cuticle and investigate the role that this protein may play in both of the previously mentioned developmental processes. (1) In higher vertebrates the paraxial mesoderm undergoes a mesenchymal-to-epithelial transformation to form segmentally organised structures called somites. Experiments have shown that signals originating from the ectoderm overlying the somites or from midline structures are required for the formation of the somites, but their identity has yet to be determined. Wnt6 is a good candidate as a somite epithelialisation factor from the ectoderm since it is expressed in this tissue. In this study we show that injection of Wnt6-producing cells beneath the ectoderm at the level of the segmental plate or lateral to the segmental plate leads to the formation of numerous small epithelial somites. We show that Wnts are indeed responsible for the epithelialisation of somites by applying Wnt antagonists which result in the segmental plate being unable to form somites. These results show that Wnt6, the only member of this family to be localised to the chick paraxial ectoderm, is able to regulate the development of epithelial somites and that cellular organisation is pivotal in the execution of the differentiation programmes. (2) The neural crest is a population of multipotent progenitor cells that arise from the neural ectoderm in all vertebrate embryos and form a multitude of derivatives including the peripheral sensory neurons, the enteric nervous system, Schwann cells, pigment cells and parts of the craniofacial skeleton. The induction of the neural crest relies on an ectodermally derived signal, but the identity of the molecule performing this role in amniotes is not known. Here we show that Wnt6, a protein expressed in the ectoderm, induces neural crest production. (3) The intracellular response to Wnt signalling depends on the choice of signalling cascade activated in the responding cell. Cells can activate either the canonical pathway that modulates gene expression to control cellular differentiation and proliferation, or the non-canonical pathway that controls cell polarity and movement (Pandur et al. 2002b). Recent work has identified the protein Naked cuticle as an intracellular switch promoting the non-canonical pathway at the expense of the canonical pathway. We have cloned chick Naked cuticle-1 (cNkd1) and demonstrate that it is expressed in a dynamic manner during early embryogenesis. We show that it is expressed in the somites and in particular regions where cells are undergoing movement. Lastly our study shows that the expression of cNkd1 is regulated by Wnt expression originating from the neural tube. This study provides evidence that non-canonical Wnt signalling plays a part in somite development.

Wnt6 controls amniote neural crest induction through the non-canonical signaling pathway

The neural crest is a multipotent embryonic cell population that arises from neural ectoderm and forms derivatives essential for vertebrate function. Neural crest induction requires an ectodermal signal, thought to be a Writ ligand, but the identity of the Wnt that performs this function in amniotes is unknown. Here, we demonstrate that Wnt6, derived from the ectoderm, is necessary for chick neural crest induction. Crucially, we also show that Wnt6 acts through the non-canonical pathway and not the beta-catenin-dependant pathway. Surprisingly, we found that canonical Wnt signaling inhibited neural crest production in the chick embryo. In light of studies in anamniotes demonstrating that canonical Wnt signaling induces neural crest, these results indicate a significant and novel change in the mechanism of neural crest induction during vertebrate evolution. These data also highlight a key role for noncanonical Wnt signaling in cell type specification from a stem population during development.

Protochordate Zic genes define primitive somite compartments and highlight molecular changes underlying neural crest evolution

The vertebrate Zic gene family encodes C2H2 zinc finger transcription factors closely related to the Gli proteins. Zic genes are expressed in multiple areas of developing vertebrate embryos, including the dorsal neural tube where they act as potent neural crest inducers. Here we describe the characterization of a Zic ortholog from the amphioxus Branchiostoma floridae and further describe the expression of a Zic ortholog from the ascidian Ciona intestinalis. Molecular phylogenetic analysis and sequence comparisons suggest the gene duplications that formed the vertebrate Zic family were specific to the vertebrate lineage. In Ciona maternal CiZic/Ci-macho1 transcripts are localized during cleavage stages by asymmetric cell division, whereas zygotic expression by neural plate cells commences during neurulation. The amphioxus Zic ortholog AmphiZic is expressed in dorsal mesoderm and ectoderm during gastrulation, before being eliminated first from midline cells and then from all neurectoderm during neurulation. After neurulation, expression is reactivated in the dorsal neural tube and dorsolateral somite. Comparison of CiZic and AmphiZic expression with vertebrate Zic expression leads to two main conclusions. First, Zic expression allows us to define homologous compartments between vertebrate and amphioxus somites, showing primitive subdivision of vertebrate segmented mesoderm. Second, we show that neural Zic expression is a chordate synapomorphy, whereas the precise pattern of neural expression has evolved differently on the different chordate lineages. Based on these observations we suggest that a change in Zic regulation, specifically the evolution of a dorsal neural expression domain in vertebrate neurulae, was an important step in the evolution of the neural crest.

Adult palatum as a novel source of neural crest-related stem cells

Somatic neural and neural crest stem cells are promising sources for cellular therapy of several neurodegenerative diseases. However, because of practical considerations such as inadequate accessibility of the source material, the application of neural crest stem cells is strictly limited. The secondary palate is a highly regenerative and heavily innervated tissue, which develops embryonically under direct contribution of neural crest cells. Here, we describe for the first time the presence of nestin-positive neural crest-related stem cells within Meissner corpuscles and Merkel cell-neurite complexes located in the hard palate of adult Wistar rats. After isolation, palatal neural crest-related stem cells (pNC-SCs) were cultivated in the presence of epidermal growth factor and fibroblast growth factor under serum-free conditions, resulting in large amounts of neurospheres. We used immunocytochemical techniques and reverse transcriptase-polymerase chain reaction to assess the expression profile of pNC-SCs. In addition to the expression of neural crest stem cell markers such as Nestin, Sox2, and p75, we detected the expression of Klf4, Oct4, and c-Myc. pNC-SCs differentiated efficiently into neuronal and glial cells. Finally, we investigated the potential expression of stemness markers within the human palate. We identified expression of stem cell markers nestin and CD133 and the transcription factors needed for reprogramming of somatic cells into pluripotent cells: Sox2, Oct4, Klf4, and c-Myc. These data show that cells isolated from palatal rugae form neurospheres, are highly plastic, and express neural crest stem cell markers. In addition, pNC-SCs may have the ability to differentiate into functional neurons and glial cells, serving as a starting point for therapeutic studies.

Isolation of novel multipotent neural crest-derived stem cells from adult human inferior turbinate

Adult human neural crest-derived stem cells (NCSCs) are of extraordinary high plasticity and promising candidates for the use in regenerative medicine. Here we describe for the first time a novel neural crest-derived stem cell population within the respiratory epithelium of human adult inferior turbinate. In contrast to superior and middle turbinates, high amounts of source material could be isolated from human inferior turbinates. Using minimally-invasive surgery methods isolation is efficient even in older patients. Within their endogenous niche, inferior turbinate stem cells (ITSCs) expressed high levels of nestin, p75(NTR), and S100. Immunoelectron microscopy using anti-p75 antibodies displayed that ITSCs are of glial origin and closely related to nonmyelinating Schwann cells. Cultivated ITSCs were positive for nestin and S100 and the neural crest markers Slug and SOX10. Whole genome microarray analysis showed pronounced differences to human ES cells in respect to pluripotency markers OCT4, SOX2, LIN28, and NANOG, whereas expression of WDR5, KLF4, and c-MYC was nearly similar. ITSCs were able to differentiate into cells with neuro-ectodermal and mesodermal phenotype. Additionally ITSCs are able to survive and perform neural crest typical chain migration in vivo when transplanted into chicken embryos. However ITSCs do not form teratomas in severe combined immunodeficient mice. Finally, we developed a separation strategy based on magnetic cell sorting of p75(NTR) positive ITSCs that formed larger neurospheres and proliferated faster than p75(NTR) negative ITSCs. Taken together our study describes a novel, readily accessible source of multipotent human NCSCs for potential cell-replacement therapy.

Adult craniofacial stem cells: sources and relation to the neural crest

During the process of development, neural crest cells migrate out from their niche between the newly formed ectoderm and the neural tube. Thereafter, they give rise not only to ectodermal cell types, but also to mesodermal cell types. Cell types with neural crest ancestry consequently comprise a number of specialized varieties, such as ectodermal neurons, melanocytes and Schwann cells, as well as mesodermal osteoblasts, adipocytes and smooth muscle cells. Numerous recent studies suggest that stem cells with a neural crest origin persist into adulthood, especially within the mammalian craniofacial compartment. This review discusses the sources of adult neural crest-derived stem cells (NCSCs) derived from the cranium, as well as their differentiation potential and expression of key stem cell markers. Furthermore, the expression of marker genes associated with embryonic stem cells and the issue of multi- versus pluripotency of adult NCSCs is reviewed. Stringent tests are proposed, which, if performed, are anticipated to clarify the issue of adult NCSC potency. Finally, current pre-clinical and clinical data are discussed in light of the clinical impact of adult NCSCs.