RESUMEN
Ossicular graft is usually considered as the reference for surgical substitution in ossiculoplasties. Nevertheless, according to the infectious risks, nothing but autografts or synthetic prosthetic substitutes should be used nowadays. Authors compare hearing results for 100 patients after ossiculoplasty with either ossicular autograft or calcium-phospathe chain reconstruction. Audiometric results were retreived using both Glasgow Benefit Plot study and post-operative air-bone gap thresholds closure. Significant hearing improvement was statistically demonstrated in both conditions, and 60% of the patients had a post-operative hearing gain. Autograft ossicular reconstructions did not show to provide higher results. Biocompatibility and functionnal properties of calcium-phosphate materials retreived in this study, indicate that those ceramic substitutes should be considered as the best alternative to autografts.
Asunto(s)
Materiales Biocompatibles , Osículos del Oído/cirugía , Prótesis Osicular , Reemplazo Osicular , Adolescente , Adulto , Audiometría , Trasplante Óseo , Fosfatos de Calcio , Cartílago/trasplante , Niño , Preescolar , Interpretación Estadística de Datos , Femenino , Estudios de Seguimiento , Audición , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Trasplante AutólogoRESUMEN
Calcium phosphate ceramics are synthetic bone substitutes that promote bone formation by osteoconduction. However, they have shown an osteogenic potential in vivo in animal models when associated with bone marrow cells. In order to develop an osteogenic human "hybrid material," we studied the in vitro osteogenic potential of human bone marrow cells cultured on macroporous biphasic calcium phosphate (BCP) pellets in the presence of dexamethasone with or without 1alpha,25 dihydroxyvitamin D3. We were examining, in particular, their mesenchymal stem cell proliferation and hematopoietic potential. Osteogenic differentiation was evaluated in terms of alkaline phosphatase activity and immunological characterization of the extracellular matrix formed by these cells. The specimens were observed by scanning and transmission electron microscopy. Human mesenchymal stem cells proliferated on macroporous BCP ceramic, with a doubling time delayed at the beginning of the culture as compared to the cultures realized on plastic. These cells maintained a hematopoietic activity identical to that of cultures performed in plastic wells. The proliferating mesenchymal stem cells expressed an osteoblastic phenotype, as shown by alkaline phosphatase activity and the synthesis in ceramic macropores of an extracellular matrix composed of fibronectin, osteocalcin, and collagen I (but not collagen III). In addition, numerous microcrystals of apatite precipitated on the extracellular matrix, producing a mineralized fibrillar network within the ceramic not observed with cell cultures realized on plastic. These results demonstrate that human mesenchymal stem cells cultured on macroporous BCP ceramic express and conserve their osteoblastic phenotype even after one month of culture and that these osteogenic cells are able to form new bone matrix in a BCP ceramic in vitro.
Asunto(s)
Células de la Médula Ósea/citología , Osteocitos/citología , Osteogénesis , Células Madre/citología , Materiales Biocompatibles , Células de la Médula Ósea/efectos de los fármacos , Calcitriol/farmacología , Fosfatos de Calcio/química , Células Cultivadas , Cerámica/química , Técnicas de Cultivo/instrumentación , Técnicas de Cultivo/métodos , Dexametasona/farmacología , Humanos , Mesodermo/citología , Microscopía Electrónica de Rastreo , Osteocitos/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Células Madre/efectos de los fármacosRESUMEN
The diagnosis of cerebrospinal fluid (CSF) fistula may require invasive techniques. Detection of CSF and perilymph-specific beta 2 transferrin and MR cisternography which greatly enhances the CSF signal are sensitive and noninvasive techniques which allowed a precise diagnosis in seven patients with suspected CSF fistula. We review the different diagnostic techniques used for CSF fistula, beta 2 transferrin analysis and MR cisternography appear to provide accurate and noninvasive methods for investigating CSF fistulae. They should replace invasive techniques such as CT cisternography.