ABSTRACT
OBJECTIVES: To evaluate the histological changes of tracheal cartilage and epithelium caused by tracheal occlusion at different gestational ages in a fetal rat model. METHODS: Rat fetuses were divided into two groups: a) External control, composed of non-operated rats, and b) Interventional group, composed of rats operated upon on gestational day 18.5 (term = 22 days), divided into triads: 1) Tracheal occlusion, 2) Internal control and 3) Sham (manipulated but not operated). Morphological data for body weight, total lung weight and total lung weight/body weight ratio were collected and measured on gestational days 19.5, 20.5 and 21.5. Tracheal samples were histologically processed, and epithelial, chondral and total tracheal thicknesses were measured on each gestational day. RESULTS: The tracheal occlusion group exhibited an increase in total lung weight/body weight ratio (p<0.001). Histologically, this group had a thicker epithelial thickness (p<0.05) and thinner chondral (p<0.05) and total tracheal thicknesses (p<0.001). These differences were more prominent on gestational days 20.5 and 21.5. CONCLUSION: Tracheal occlusion changed tracheal morphology, increased epithelial thickness and considerably decreased total tracheal thickness. These changes in the tracheal wall could explain the development of tracheomegaly, recently reported in some human fetuses subjected to tracheal occlusion.
Subject(s)
Animals , Rats , Fetus/surgery , Gestational Age , Models, Animal , Therapeutic Occlusion/methods , Trachea/surgery , Age Factors , Body Weight , Fetus/anatomy & histology , Fetus/embryology , Lung/anatomy & histology , Lung/embryology , Organ Size , Reproducibility of Results , Time Factors , Therapeutic Occlusion/adverse effects , Trachea/anatomy & histology , Trachea/embryologyABSTRACT
The extracellular matrix is a key element in the tracheal morphology and physiology, both in normal and pathological states, yet little is known regarding its composition and organization. Herein we carried out a detailed study of the morphological organization and volumetric density of elastic system fibers in the trachea of Wistar rats. Six Wistar rats at the age of 45 days were used. The trachea was excised following anesthesia with Thiopental and perfusion through the left ventricle with buffered saline followed by formalin solution. Samples were fixed in formaline, embedded in paraffin, and histologically processed. The elastic system fibers were evaluated at light microscopy by using Weigert's resorcin-fuchsin technique after oxidation with oxone. Morphometric studies were performed by the point-counting method. Quantities were expressed ( percent, mean) as volumetric densities and were determined on 25 random fields for each animal. Elastic system fibers were identified beneath the tracheal mucosa showing mainly a longitudinal profile. There were also some bundles of oblique fibers in this region, forming an irregular network of elastic tissue. Close to the inner surface of the cartilaginous ring, a well defined circular layer is present. The volumetric density of the elastic system fibers in the trachea of Wistar rats is 2.46 +/- 0.99 percent. The data in the present study provides original information regarding the elastic system fibers of the rat trachea, which might be used as a model for studying human major airway morphology. The results reported herein provide the basis for continuous investigations on tracheal extracellular matrix by stereology.
La matriz extracelular es un elemento clave en la morfología y fisiología de la tráquea, tanto en estados normales como patológicos. Sin embargo, poco se sabe acerca de su composición y organización. Se llevó a cabo un estudio detallado de la organización morfológica y la densidad volumétrica de fibras del sistema elástico en la tráquea de ratas Wistar. Se utilizaron seis ratas Wistar edad de 45 días de vida. La tráquea fue extraída después de anestesia con tiopental y la perfusión a través del ventrículo izquierdo con solución salina tamponada seguido de solución de formalina. Las muestras fueron fijadas en formalina e incluidas en parafina y se procesaron histológicamente. Las fibras del sistema elástico fueron evaluadas en microscopía de luz utilizando la técnica de Weigert, resorcina-fucsina después de la oxidación con Oxone. Los estudios morfométricos fueron realizados por el método de conteo de puntos. Las cantidades se expresaron ( por ciento, media) como la densidad volumétrica y se determinaron en 25 campos al azar para cada animal. Las fibras elásticas del sistema fueron identificadas por bajo la mucosa traqueal que muestra principalmente un perfil longitudinal. También se encontraron algunos haces de fibras oblicuas en esta región, formando una red irregular de tejido elástico. Cerca de la superficie interna del anillo cartilaginoso, una capa bien definida circular está presente. La densidad volumétrica de las fibras del sistema elástico en la tráquea de ratas Wistar fue de 2,46 +/- 0,99 por ciento. Los datos del presente estudio proporcionan información inicial sobre las fibras del sistema elástico de la tráquea de rata, que puede ser utilizado como un modelo para el estudio de la morfología de las vías respiratorias humanas. Los resultados reportados en este documento constituyen la base de investigaciones continuas en la tráquea de la matriz extracelular por estereología.
Subject(s)
Adult , Rats , Trachea/anatomy & histology , Trachea/embryology , Trachea/innervation , Trachea/blood supply , Trachea , Trachea/ultrastructure , Evaluation Studies as Topic/methods , Rats, Wistar/anatomy & histologyABSTRACT
The three vessel and three vessels and trachea views are reliable method with which to determine abnormalities in the upper mediastinum. Both have proved to be efficient in identifying an important group of major and critical heart defects involving the outflows tracts and the aortic arch. It also provides important clues to diagnose minor anomalies considered as markers of other congenital heart defect. Moreover, detection of reverse flow in a this transverse views is associated with complex heart defects, with major diminution of forward flow to the corresponding great vessels. A reverse shunt at this level allows the selection of a group of fetuses t risk of sudden rapid deterioration in early neonatal period.
Las visiones de 3 vasos y 3 vasos- tráquea son simples y confiables planos de visión del mediastino superior fetal. Han demostrado ser eficaces para identificar un grupo importante de defectos mayores y críticos relacionados con los tractos de salida y el arco aórtico. También entrega claves para el diagnóstico de lesiones menores, consideradas marcadores de cardiopatías congénitas. Más aún, el uso de color y la visualización de un flujo reverso en estas secciones transversas se asocian a anomalías complejas, que determinan una marcada disminución del flujo sanguíneo a través del vaso correspondiente. La detección de un flujo reverso a este nivel selecciona a fetos en riesgo genuino de presentar un deterioro brusco en el periodo neonatal inmediato.
Subject(s)
Humans , Female , Pregnancy , Heart Defects, Congenital , Fetal Heart , Ultrasonography, Prenatal , Aorta/embryology , Aorta , Pulmonary Artery/embryology , Pulmonary Artery , Heart Defects, Congenital/embryology , Mediastinum , Trachea/embryology , Trachea , Vena Cava, Superior/embryology , Vena Cava, SuperiorABSTRACT
We described the macroscopic and quantitative anatomy of the trachea of the Giraffe (Giraffa camelopardalis rothschildi). The trachea of one juvenile male giraffe (25 months of age) weighing 754 kg was used in this study. The length of the neck was 125 cm. The trachea had 107 cm in length on its cervical part and 18 cm on its thoracic part. The total number of cartilage was 87.74 at the neck and 13 at the thorax. The general shape of the duct was mostly circular. The separation of the dorsal ends of the tracheal cartilages was pronounced in the first half of the cervical trachea, reducing caudally and overlapping in the thoracic trachea. In the caudal part the trachea had a tracheal bronchus for the cranial lobe of the right lung and the end of the trachea was divided into two main bronchi, where the left was larger in diameter.
Describimos la anatomía macroscópica y cuantitativa de la tráquea de la jirafa (Giraffa camelopardalis rothschildi). La tráquea de una jirafa macho joven (25 meses de edad), con un peso 754 kg fue utilizada en este estudio. La longitud del cuello era de 125 cm. La tráquea tuvo 107 cm de longitud en su parte cervical y 18 cm en su parte torácica. El número total de cartílagos fue de 87,74 en el cuello y 13 en el tórax. La forma general de la vía fue principalmente circular. La separación de los extremos dorsales de los cartílagos traqueales se pronunció en la primera mitad de la tráquea cervical, reduciéndose caudalmente y superponiéndose en la tráquea torácica. En la parte caudal la tráquea tenía un bronquio traqueal para el lobo craneal del pulmón derecho y el final de la tráquea se dividió en dos bronquios principales, donde el izquierdo fue de mayor diámetro.