Beta1 integrin and VEGF expression in an experimental model of brain tissue heterotopia in the lung.

INTRODUCTION: Integrins and vascular endothelial growth factor (VEGF) are crucially involved in interaction, proliferation, migration, and survival of the cells. However, there is no report in the literature about beta1 integrin and VEGF expression in heterotopic brain tissue. PURPOSE: The aim of this study was to assess beta1 integrin and VEGF expression in experimental brain tissue heterotopia in the lung during both fetal and neonatal periods. MATERIALS AND METHODS: Twenty-four pregnant female Swiss mice were used to induce brain tissue heterotopia on the 15th gestational day. Briefly, the brain of one fetus of each dam was extracted, disaggregated, and injected into the right hemithorax of siblings. Six of these fetuses with pulmonary brain tissue implantation were collected on the 18th gestational day (group E18) and six other on the eighth postnatal day (group P8). RESULTS: Immunohistochemistry of the fetal trunks showed implantation of glial fibrillary acidic protein- and neuronal nuclei-positive heterotopic brain tissue, which were also positive for beta1 integrin and VEGF in both groups E18 and P8. CONCLUSION: These results indicate that brain tissue heterotopia during fetal and postnatal period is able to complete integration with the lung tissue as well as to induce vascular proliferation which are the necessary steps for a successful implantation.

Effect of rehabilitation protocols on muscle function and morphology following hindlimb disuse in weanling rats.

BACKGROUND: Primary or secondary disorders in developing skeletal muscles are prevalent in physical therapy practice. Assessment of gait functional changes and morphological aspects of hindlimb muscles of weanling rats have not been reported simultaneously in the literature. Rehabilitation by active (eccentric training) and passive (stretching) exercises after hypomobility needs to be investigated. METHODS: After ten days of immobilisation in a plantar flexion-shortened position, animals underwent eccentric training on treadmills, intermittent (a single series of ten exercises of 30 seconds each, with a 30-s interval) or continuous stretching protocols for 40 minutes, or had free cage activity for three days. Analysis of gait variables and muscle morphology (immunohistochemical staining of soleus and plantar muscles for fibronectin and types I and III collagen and immunofluorescence staining for dystrophin, laminin, Pax-7, and CD68) were performed. RESULTS: On the third day, the rehabilitated animals touched the ground surface with their toes, except for the group undergoing continuous stretching. The total amount of extracellular macrophages was higher in the rehabilitated animals. The number of satellite cells was not significantly different between groups. CONCLUSION: Three days of active training (eccentric exercise) showed greater effectiveness compared to the other rehabilitation programs. Weanling rats seem to respond differently to external stimuli such as disuse and remobilisation.