ABSTRACT
RESUMEN: Para que se desarrolle el iris, se requiere una especificación de la capa periférica de la copa óptica a un destino no neuronal y además la migración de células mesenquimales perioculares. Nuestro objetivo fue reconocer los cambios histológicos de los derivados periféricos de la copa óptica y mesénquima periocular, como también reconocer la presencia del morfógeno Sonic hedgehog (Shh) en las capas que constituyen el esbozo de iris. Se utilizaron 15 ratones hembras (Mus musculus) adultas jóvenes gestantes. Se realizó eutanasia con tiopental sódico. Los embriones y fetos de 12, 14,5 y 17 días post-coital (dpc) fueron procesados con técnica histológica e inmunohistoquímica con anticuerpo anti-Shh (scbt, H-160, conejo) con dilución 1:100 en PBS. A los 12 dpc, se observa una cópa óptica que presenta capas retinianas interna y externa, y el iris no se observa. Entre el cristalino y el ectodermo superficial se identifican 4 capas de células mesenquimales. A los 14,5 dpc, el iris contiene dos capas epiteliales (interna y externa) que se continúan con las capas neural y pigmentaria de la retina. Se observan 8 capas de células mesenquimales. A los 17 dpc, la capa epitelial interna del iris presenta un segmento más elongado con inmunotinción positiva a Shh y otra parte que constituye un epitelio de células cilíndricas simples negativas a este anticuerpo. La capa epitelial externa presenta el mismo epitelio inmunonegativo. Las capas de la retina también son positivas, como también la periferia del cristalino. No esta formado el iris ni tampoco el cuerpo ciliar. La inmunopositividad en el cristalino, en el primer segmento de la capa interna del esbozo del iris y en la capa ganglionar retinal a los 17 dpc, se relaciona con la diferenciación tardía del iris y con los ojos cerrados de las crías al nacimiento.
SUMMARY: In order for the iris to develop, a specification of the peripheral layer of the optic cup to a non-neuronal target is required, as well as the migration of periocular mesenchymal cells. Our aim was to recognize the histological changes of peripheral derivatives of the optic cup and periocular mesenchyme, as well as recognize the presence of the morphogen Sonic hedgehog (Shh) in the layers constituting the outline of the iris. 15 female mice (Mus musculus) pregnant young adults were used. Euthanasia was performed with sodium thiopental. Embryos and fetuses of 12, 14.5 and 17 days post-coital (dpc) were processed with histological and immunohistochemical technique with anti-Shh antibody (scbt, H 160, rabbit) with dilution 1:100 in PBS. At 12 dpc, an optic cup showing internal and external retinal layers is observed, and the iris is not observed. Between the lens and the superficial ectoderm, 4 layers of mesenchymal cells are identified. At 14.5 dpc, the iris contains two epithelial layers (internal and external) that are continued with the neural and pigmentary layers of the retina. 8 layers of mesenchymal cells are observed. At 17 dpc, the inner epithelial layer of the iris presents a more elongated segment with positive immunostaining to Shh and another part that constitutes an epithelium of simple cylindrical cells negative to this antibody. The outer epithelial layer presents the same immunonegative epithelium. The layers of the retina are also positive, as well as the periphery of the lens. The iris is not formed nor is the ciliary body.The immunopositivity in the lens, in the first segment of the inner layer of the iris outline and in the retinal ganglion layer at 17 dpc, is related to the late differentiation of the iris and the closed eyes of the offspring at birth.
Subject(s)
Animals , Female , Mice , Iris/embryology , Eye/embryology , Hedgehog Proteins , Iris/anatomy & histology , Eye/anatomy & histology , MorphogenesisABSTRACT
Neural tube defects, growth retardation and nail hypoplasia are most common features of teratogenic effects of carbamazepine. This study was done to determine the effects of carbomazepine on eye development in Mice fetuses. In this experimental study 40 BALB/c pregnant Mice were divided into four groups. Experimental groups I and II received 15 mg/kg daily 6-15 GD [gestational days] and 30 mg/kg daily 6-15 GD intraperitoneal of carbamazepine, respectively. All drugs recolved in Tween20. Two control groups received normal saline or Tween 20. Dams were dissected on GD18 and embryos were collected. After observation of eye malformation in fetuses, we employed routine histological processes to stain the samples and also skeletal staining was performed. Calvaria deformations, finger anomalies, brachygnathia and short tail in experimental groups I and II were 7% and 10.8%, 13.3% and 16.6%, 7.8% and 11.7%, 10.2% and 9.2% respectively. Ten of fetuses [8.6%] in experimental group I and nine of fetuses [7.5%] in the experimental group II had eye malformations. Premature opening of one or both eyes with mild to severe exophthalmos occurred in both of the experimental groups. Also, histological examination showed deformed lens, retinal folds with undeveloped layers, corneal fold with absence of surface epithelium. This study revealed that administration of carbamazepine during embryunic period can induce eye malformations in Mice fetuses
Subject(s)
Female , Animals, Laboratory , Eye/embryology , Mice , Neural Tube Defects , Fetal Growth Retardation , Gestational Age , Teratogens , Congenital Abnormalities/etiology , Abnormalities, Drug-Induced , Eye/growth & developmentABSTRACT
The dorsoventral axis of the eye is determined prior to optic cup invagination. A variety of signaling pathways have been implicated in the maintenance of the optic dorsoventral axis, including, but not limited to, bone morphogenetic protein 4, Sonic Hedgehog and retinoic acid. Here, we investigated the possible contribution of Wnt ligands to the establishment or maintenance of the optic axis by analyzing their expression pattern during early chick optic development. We performed in situ hybridization of Wnt-1, Wnt-3a, Wnt-4, and Wnt-5a during the optic vesicle, early optic cup and established optic cup stages and focused our analysis on the optic region. Our data showed that Wnt-5a, but none of the others, is expressed in the dorsal region of the eye starting from the Hamburger and Hamilton stage 14 (HH14). These results are supported by cryosections of the labeled optic region, which further reveal that Wnt-5a is expressed only in the dorsal retinal pigmented epithelium. Thus, we propose that Wnt-5a is a marker for dorsal retinal pigmented epithelium in chick embryos from HH14 to HH19.
Subject(s)
Animals , Chick Embryo , Female , Body Patterning , Eye/embryology , Wnt Proteins/metabolism , Eye/metabolism , In Situ Hybridization , Ligands , Signal TransductionABSTRACT
O estudo avaliou a possível ação teratogênica do aldrin sobre o olho. O lote era constituído de 13 ratas (8 receberam aldrin e 5 foram controles), que foram sacrificadas no vigésimo dia de gestação. Os fetos retirados foram estudados por técnicos estereológicos, usando-se a grade de Haug modificada. Naquelas cujas mães receberam inalação de aldrin houve interferência na formação das pálpebras, que ficaram mais espessas, e na câmara anterior, que teve seu volume aumentado
Subject(s)
Rats , Female , Pregnancy , Animals , Aldrin/toxicity , Eye/drug effects , Eye/embryology , Fetal Development/drug effects , Rats, WistarABSTRACT
En este trabajo se analizaron las variaciones de la matriz extracelular en distintas etapas del desarrollo ocular del ratón. Cabezas de embriones de 11, 13, 14, 17 días de gestación y de término se fijaron en Dubosq-Brasil, se incluyeron en parafina y se realizaron cortes seriados transversales de 6 *m que se tiñeron con hematoxilina-eosina, azul Alcián (pH 2,5), PAS, Gomori y Picrosirius. Además se hicieron los tratamientos enzimáticos correspondientes con diastasa, hialuronidasa testicular y papaína. Aunque las técnicas utilizadas no son cuantitativas, evidenciaron que la tinción de la membrana basal del estrato pigmentario de la retina va aumentando. Las membranas basales del epitelio anterior del lente y del extremo anterior del bulbo óptico están íntimamente adosadas, destacándose por su grosor y por la intensidad de la tinción con las técnicas de PAS y azul de Alcián. Probablemente, esto podría estar relacionado con la formación del iris, procesos ciliares y zónula. Nuestras observaciones sugieren que las variaciones de los componentes de la matriz extracelular de las membranas basales del esbozo del ojo, jugarían un rol en las interacciones que son determinantes en el desarrollo de las estructuras oculares
Subject(s)
Extracellular Matrix/physiology , Eye/embryologyABSTRACT
Se estudió la aplicación de un caso de síndrome de Goldenhar's'', el cual presentó después de haber confirmado su diagnóstico por historia clínica, biomicroscopia, oftalmoscopia directa e indirecta, ecografía, RX cráneo, órbita y columna vertebral, TAC, exámenes de gabinete, etc. Este caso ha sido estudiado en conjunto por los servicios de pediatría, neurocirugía, oftalmología, cardiología, cirugía plástica y radiología. Llegando a resolver su neuroquirúrgico, quedando por solucionar la ciruga del quiste dermoide y del mamelón preuricular
Subject(s)
Child, Preschool , Humans , Female , Eye/embryology , Eye/pathology , Ear/embryology , Ear/pathology , Goldenhar Syndrome/diagnosis , Goldenhar Syndrome/pathologyABSTRACT
Foram realizadas mediçöes do diâmetro transversal equatorial ocular em 224 fetos de gestantes normais utilizando-se um ecógrafo Toshiba equipado com transdutor de 2,4 MHz. A idade gestacional dos fetos oscilou entre 12 e 19 semanas. O diâmetro ocular médio variou de 3,3 mm na 12ª semana até 18,9 mm na 39ª. O crescimento ocular mostrou-se mais rápido na primeira metade da gestaçäo diminuindo paulatinamente até chegar a um mínimo nas últimas semanas. Com os dados obtidos foi posssivel construir nomogramas aplicáveis ao nosso meio, que poderäo auxiliar na detecçäo intra-uterina de diversas patologias
Subject(s)
Pregnancy , Humans , Female , Eye/embryology , Prenatal Diagnosis , Ultrasonography , Gestational AgeABSTRACT
Se ha realizado un analisis de transmision genetica del caracter ojo rojo en T.infestans recolectados en Tatarenda, Prov. Cordillera, Departamento Santa Cruz. Los datos obtenidos de las dos primeras generaciones nos hacen concluir que este caracter (o.r) es recesivo autoosomico, confirmando los trabajos de Wygodzinsky y Briones. No esta ligado alsexo como concluyeron Noe y Silva
Subject(s)
Animals , Eye/embryology , Triatoma/genetics , Bolivia , Genes, Recessive , PhenotypeABSTRACT
Entre o olho da criança e o adulto existem peculiaridades e diferenças que explicam certas patologias específicas e permitem certas indagaçöes sobre sua natureza. O Autor demonstra as diferenças embriológicas e de desenvolvimento e tece consideraçöes sobre estas diferenças