Noise-induced duodenal lesions

Vibroacoustic disease (VAD) is a systemic diseasethat results from long-term exposure tolow-frequency noise (LFN). VAD can cause lesionsin several organs. Noise-exposed individualsfrequently present digestive symptoms, butonly a few studies have attempted to evaluategastrointestinal lesions. The aim of this studywas to investigate the duodenal alterations inVAD, using an animal model of the disease.Adult Wistar rats were exposed to continuousLFN. After five, nine and thirteen weeks theywere sacrificed. The duodenums were studiedby light microscopy and scanning electron microscopy,and compared with those of animalskept in silence. Superficial erosions and widespreadcell death with microvilli coalescence andfusion were observed, by light and electronmicroscopy. Erosion, cellular degeneration anddeath, and microvilli destruction, reflect noise-inducedduodenal alterations in rats which may beequivalent to the ulcers and dyspeptic symptomsreported in human VAD patients (AU)

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Experimental autotransplantation of the trachea: structural changes studied in the rabbit with a reference to human tracheal stenosis / Autotrasplante experimental de la tráquea: cambios estructurales estudiados en el conejo con referencia a la estenosis de la tráquea humana

Transplantation of the trachea is envisaged as the treatment of the future for severe cases of tracheal stenosis. In order to investigate the structural consequences of tracheal transplantation, we studied the adaptive changes of tracheal autografting in the rabbit. We found that auto-transplantation of long portions of the trachea (involving 10 cartilage rings) was not viable in the rabbit, in contrast with the complete success observed after grafting of 4-ring segments of trachea. We report here on the morphological modifications of the trachea in these successful 4-ring autograftings of the organ. Marked epithelial alterations were seen in the early stage (one week) of the tracheal autografting, consisting of the loss of cilia and increase in the number of mucous cells. Two weeks after surgery, there was evidence of partial recovery by the epithelium. At three months after autografting, the epithelium was almost completely covered with cilia, the submucosa was poor in elastic fibers and cartilage foci were found outside the rings. Six months after surgery, the entire luminal surface of the rabbit trachea was covered with cilia; these samples showed discontinuities in the basement membrane and a paucity in elastic fibers. Major alterations were detected in the cartilage components of the autografted trachea, consisting in the fusion of adjacent rings and, at the suture lines, partial superimposition of rings. We conclude that the epithelium and the cartilage components of the trachea show distinct responses to autografting: changes in the epithelium are severe in the acute phase but are transitory and disappear in the long run, whereas alterations of the cartilage are initially less conspicuous but slowly develop into the neoformation of cartilage tissue with fusion and superimposition of some tracheal rings, causing moderate tracheal stenosis (AU)

Se considera al trasplante de la tráquea como tratamiento del futuro para casos graves de estenosis traqueal. Para investigar las consecuencias estructurales del trasplante traqueal, en este trabajo estudiamos los cambios adaptativos del autotrasplante traqueal en el conejo. Observamos que el autotrasplante de porciones largas de la tráquea (implicando 10 segmentos de cartílago) no era viable en esta especie, a diferencia con el éxito rotundo observado tras el transplante de segmentos de tráquea de 4 anillos. Aquí describimos las modificaciones morfológicas de la tráquea en estos autotrasplantes exitosos de 4 anillos Se observaron alteraciones epiteliales pronunciadas en la fase temprana (una semana) después del autotrasplante traqueal; dichas alteraciones consistían en la pérdida de cilios y aumentos en el número de células mucosas. Dos semanas después de la intervención quirúrgica se apreciaron evidencias de una recuperación parcial del epitelio. A los tres meses del autotrasplante, el epitelio estaba casi completamente revestido de cilios, la submucosa estaba pobre en fibras elásticas y se encontraron focos de cartílago en el exterior de los anillos. A los seis meses, la superficie luminal entera de la tráquea del conejo estaba revestida de cilios: estas muestras exhibían discontinuidades en la membrana basal y una pobreza de fibras elásticas. Se detectaron alteraciones importantes en los componentes cartilaginosos de la tráquea autotrasplantada, consistiendo en la fusión de anillos adyacentes y -en las líneas de sutura- una superimposición parcial de los anillos. Concluimos que el epitelio y los componentes cartilaginosos de la tráquea muestran respuestas diferentes al autotrasplante: los cambios en el epitelio son pronunciados en la fase aguda pero a largo plazo son transitorios y desaparecen, mientras que las alteraciones en el cartílago son inicialmente menos conspicuas pero poco a poco se desarrollan en la neoformación de tejido cartilaginoso, con la fusión y superposición de algunos anillos traqueales, causando un grado moderado de estenosis traqueal (AU)