RESUMEN
BACKGROUND: Many reports have described tracheal replacement using aortic allografts, with varying results and minimal understanding of the mechanism of tracheal regeneration. The present study attempted tracheal regeneration in adult dogs using fresh aortic allografts (FAA) and cryopreserved aortic allografts (CAA). MATERIALS AND METHODS: Twelve adult beagles underwent tracheal resection and were transplanted with FAA (n = 5) or CAA (n = 7). Animals were followed-up with serial radiography and magnetic resonance imaging, and were euthanized at predetermined times up to 16 mo post-surgery. RESULTS: There were no procedural deaths, but two animals died due to stent migration. Stent migration occurred in seven of the 12 animals. Evidence of regeneration of tracheal epithelium was observed in the surviving animals, with the transformation of squamous metaplasia to mucociliary epithelium being time-dependent. Islet of cartilage were observed in animals after 6 mo, but ring-like cartilage structures were absent, even after 16 mo. During autopsy, axial graft contractions up to 68% were observed. Serial radiographs show that most of the contraction occurred within 1 mo. The results of the MRI showed that the graft area was strongly enhanced for up to 2 mo, but was clearly reduced after 3 mo. CONCLUSIONS: Tracheal replacement in adult dogs using FAA or CAA is feasible. However, immaturity of the neotracheal cartilage did not allow the tissue to function as native tracheal tissue. Prolonged stenting should be considered in adult if the procedure is to be clinically contemplated.
Asunto(s)
Aorta/trasplante , Criopreservación , Tráquea/fisiología , Tráquea/cirugía , Trasplantes , Animales , Aorta/patología , Perros , Imagen por Resonancia Magnética , Modelos Animales , Radiografía Torácica , Regeneración/fisiología , Stents , Tráquea/patología , Trasplante Homólogo , Resultado del TratamientoRESUMEN
We induced percutaneous spinal cord injuries (SCI) using a balloon catheter in 45 rats and transplanted human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) at the injury site. Locomotor function was significantly improved in hUCB-MSCs transplanted groups. Quantitative ELISA of extract from entire injured spinal cord showed increased expression of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and neurotrophin-3 (NT-3). Our results show that treatment of SCI with hUCB-MSCs can improve locomotor functions, and suggest that increased levels of BDNF, NGF and NT-3 in the injured spinal cord were the main therapeutic effect.
Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/genética , Trasplante de Células Madre de Sangre del Cordón Umbilical , Regulación de la Expresión Génica , Traumatismos de la Médula Espinal/terapia , Animales , Ensayo de Inmunoadsorción Enzimática , Perfilación de la Expresión Génica , Humanos , Locomoción , Factor de Crecimiento Nervioso/genética , RatasRESUMEN
Here, percutaneous spinal cord injury (SCI) methods using a balloon catheter in adult rats are described. A balloon catheter was inserted into the epidural space through the lumbosacral junction and then inflated between T9-T10 for 10 min under fluoroscopic guidance. Animals were divided into three groups with respect to inflation volume: 20 µL (n = 18), 50 µL (n = 18) and control (Fogarty catheter inserted but not inflated; n = 10). Neurological assessments were then made based on BBB score, magnetic resonance imaging and histopathology. Both inflation volumes produced complete paralysis. Gradual recovery of motor function occurred when 20 µL was used, but not after 50 µL was applied. In the 50 µL group, all gray and white matter was lost from the center of the lesion. In addition, supramaximal damage was noted, which likely prevented spontaneous recovery. This percutaneous spinal cord compression injury model is simple, rapid with high reproducibility and the potential to serve as a useful tool for investigation of pathophysiology and possible protective treatments of SCI in vivo.
Asunto(s)
Embolectomía con Balón/métodos , Compresión de la Médula Espinal/terapia , Animales , Modelos Animales de Enfermedad , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
The use of human umbilical cord blood-derived mesenchymal stem cells for cell transplantation therapy holds great promise for repairing spinal cord injury. Here we report the first clinical trial transplantation of human umbilical cord (hUCB)-derived mesenchymal stem cells (MSCs) into the spinal cord of a dog suspected to have fibrocartilaginous embolic myelopathy (FCEM) and that experienced a loss of deep pain sensation. Locomotor functions improved following transplantation in a dog. Based on our findings, we suggest that transplantation of hUCB-derived MSCs will have beneficial therapeutic effects on FCEM patients lacking deep pain sensation.