Growth factor expression after supraspinatus tear: a quantitative polymerase chain reaction (PCR) study in rats.

INTRODUCTION: The objective of this study was to evaluate the temporal expression pattern of three different growth factors (VEGF, IL-1ß, and TGF-1ß) in a supraspinatus tendon lesion in an animal model. The hypothesis of this study is that there are variations in the expression of these factors in the first 8 weeks after injury. MATERIALS AND METHODS: A full thickness defect was made in the supraspinatus tendon of 40 rat shoulders. The animal were sacrificed at 0, 3, 7, 14 and 56 days after injury and three tissue samples were obtained: bone from the tendon footprint; the supraspinatus tendon stump, and a fragment of the myotendinous junction. After mRNA extraction, quantitative PCR analysis was performed, and the expression of three different growth factors were evaluated in each zone. RESULTS: There was an increased expression of IL-1ß during the first week after injury at all levels evaluated with a clear peak in the first day after injury. There was also a significant increase in TGF-1ß expression levels all along the first week in the three zones. There were no variations in VEGF expression in the three zones along the 8 weeks. CONCLUSION: IL-1ß was expressed predominantly in the initial stages after injury; TGF initiated its expression after the initial phase since day three, whereas VEGF remained basically unchanged during the entire process.

Osteosarcomas parostales: resultados infrecuentes / Parosteal osteosarcomas: unusual findings

Objetivo. Estudiar y evaluar los hallazgos poco frecuentes en la historia natural de los osteosarcomas parostales. Los osteosarcomas parostales son tumores bien diferenciados de bajo grado de malignidad. La desdiferenciación en una lesión más agresiva. Material y método. Se revisaron una serie de 7 osteosarcomas parostales tratados en el Hospital la Paz entre 2005 y 2009 (tres fueron osteosarcoma parostales desdiferenciados). Los autores analizaron las características clínicas y radiológicas, la histología, tratamiento y resultados en este grupo de pacientes. Resultados. La distribución por sexos fueron: 5 varones y dos mujeres. La edad media de los pacientes fue: 32,14 años; rango: 24-47 años. Tres tumores de 7 (42,8%) fueron osteosarcomas desdiferenciados. Los tres pacientes recibieron quimioterapia. Un paciente debutó con metástasis pulmonares. Ningún paciente falleció. Conclusiones. Es importante la comprensión que el fenómeno biológico de la desdiferenciación puede ocurrir en los osteosarcomas parostales. El pronóstico, tratamiento y supervivencia cambia radicalmente (AU)

Objective. To study and evaluate the unusual findings in the natural history of parosteal osteosarcomas. Parosteal osteosarcomas are well-differentiated tumours of low grade malignancy, but may dedifferentiate into a more aggressive lesion. Material and methods. We reviewed 7 parosteal osteosarcomas treated in La Paz Hospital between 2005 and 2009 (3 were dedifferentiated parosteal osteosarcomas). The authors analysed the clinical and radiological features, histology, treatment and outcomes in this patient group. Results. There were 5 men and 2 women, with a mean age of 32.14 years, range 24-47 years. Three of seven tumours (42.8%) were dedifferentiated osteosarcomas. All three patients received chemotherapy. One patient presented with pulmonary metastases. No patient died. Conclusions. It is important to understand that the biological phenomenon of dedifferentiation can occur in parosteal osteosarcomas. The prognosis, treatment and survival changes radically (AU)

[Parosteal osteosarcomas: unusual findings]. / Osteosarcomas parostales: resultados infrecuentes.

OBJECTIVE: To study and evaluate the unusual findings in the natural history of parosteal osteosarcomas. Parosteal osteosarcomas are well-differentiated tumours of low grade malignancy, but may dedifferentiate into a more aggressive lesion. MATERIAL AND METHODS: We reviewed 7 parosteal osteosarcomas treated in La Paz Hospital between 2005 and 2009 (3 were dedifferentiated parosteal osteosarcomas). The authors analysed the clinical and radiological features, histology, treatment and outcomes in this patient group. RESULTS: There were 5 men and 2 women, with a mean age of 32.14 years, range 24-47 years. Three of seven tumours (42.8%) were dedifferentiated osteosarcomas. All three patients received chemotherapy. One patient presented with pulmonary metastases. No patient died. CONCLUSIONS: It is important to understand that the biological phenomenon of dedifferentiation can occur in parosteal osteosarcomas. The prognosis, treatment and survival changes radically.