RESUMEN
Musculotendinopathy at the origin of the gastrocnemius muscle is a rare disease mostly described in herding dogs. The etiology is based on repeated myotendinous strain of the muscle in athletic dogs. Clinically, the patient displays chronic pelvic limb lameness and pain at the lateral fabella during palpation of this area. There is no instability of the stifle present. Radiographic findings (osteophyte formation at the origin of the muscle and the lateral fabella) support the potential diagnosis. Magnetic resonance tomography shows edematous changes and enhancement after intravenous application of contrast agent in the area of the origin of the lateral gastrocnemius head. With conservative treatment (i. e. leash confinement, NSAID application and physiotherapy) the prognosis is good. This case report describes clinical findings, diagnostic imaging, therapy and long-term outcome of an athletic Labrador Retriever presented with this disease.
Asunto(s)
Enfermedades de los Perros/patología , Cojera Animal/patología , Músculo Esquelético/patología , Rodilla de Cuadrúpedos/patología , Tendinopatía/veterinaria , Animales , Enfermedades de los Perros/diagnóstico por imagen , Perros , Cojera Animal/diagnóstico por imagen , Masculino , Músculo Esquelético/diagnóstico por imagen , Radiografía , Rodilla de Cuadrúpedos/diagnóstico por imagen , Tendinopatía/diagnóstico por imagen , Tendinopatía/patologíaRESUMEN
BACKGROUND: Wilms tumors (WTs) are embryonic neoplasms of the kidney that are believed to arise from primitive metanephrogenic blastema. Our previous reports and those of others indicate that WTs show an increased expression of insulin-like growth factor II (IGF-II) mRNA. However, the precise role of IGF-II on Wilms tumorigenesis is not known. A central question is to determine whether the increased IGF-II expression in WTs simply reflects the fetal nature of WTs (effect), or is induced by specific changes in gene expression (cause). EXPERIMENTAL DESIGN: This study included 31 sporadic WTs, 7 fetal and 3 adult kidneys and 1 yolk sac tumor. Clinical and histologic summaries of WT cases are shown in Table 1. In WTs, the relative area of blastemal, epithelial, poorly differentiated spindle cell and heterologous cell components were assessed. Dot and Northern blot hybridization, using cDNA probes, were done to assess the level of IGF-II mRNA expression. In situ RNA hybridization was employed to localize IGF-II transcripts. Immunohistochemistry was applied to frozen sections to demonstrate cytokeratin and type-IV collagen. These results were then correlated with the histology of WTs and their precursor lesions, i.e., nephrogenic rests (NRs). RESULTS: Dot blot hybridization indicated that IGF-II transcripts were 32- to 64-fold more abundant in WTs than in the adjacent uninvolved kidneys. In situ hybridization showed that WTs, NRs, and fetal kidney shared a common feature in which IGF-II transcripts were predominantly associated with blastema. However, WTs and NRs differed from fetal kidney in that occasional epithelial structures and dense blastema showed aberrant, sustained IGF-II expression. CONCLUSIONS: The data indicate two points. 1) There is an inverse correlation between nephroblastic differentiation and IGF-II expression in developing fetal kidney. 2) The IGF-II expression in WTs and NRs does not simply reflect the embryonal nature of the tumor but is rather significantly altered, suggesting a role as a transforming growth factor in Wilms tumorigenesis.