A new type of anti-ganglioside antibodies present in neurological patients

AbstractHigh titers of anti-GA1 antibodies have been associated with neurological syndromes. In most cases, these antibodies cross-react with the structurally related glycolipids GM1 and GD1b, although specific anti-GA1 antibodies have also been reported. The role of specific anti-GA1 antibodies is uncertain since the presence of GA1 in the human nervous system has not been clarified. A rabbit was immunized with GD1a and its sera were screened for antibody reactivity by standard immunoassay methods (HPTLC-immunostaining and ELISA). Anti-GD1a antibodies were not detected but, unexpectedly, anti-GA1 IgG-antibodies were found. Antibody binding to GA1 was inhibited by soluble GA1 but also by GD1a. These results indicate that the rabbit produced antibodies that recognize epitopes present on the glycolipids, that are absent or not exposed on solid phase adsorbed GD1a. We investigated the presence of these unusual anti-ganglioside antibodies in normal and neurological patient sera. Approximately, 10% of normal human sera contained low titer of specific anti-GA1 IgG-antibodies but none of them recognized soluble GD1a. High titers of IgG-antibodies reacting only with GA1 were detected in 12 patient sera out of 325 analyzed. Of these, 6 sera showed binding that was inhibited by soluble GD1a and four of them also by GM1. This new type of anti-ganglioside antibodies should be considered important elements for understanding of the pathogenesis of these diseases as well as their diagnosis

Caracterización biológica de un composite de Hidroxiapatita bovina sinterizada

El objetivo principal de este estudio fue evaluar la morfología y adhesión celular de dos líneas celulares cultivadas en presencia de un composites de hidroxiapatita bovina sinterizada preparada en nuestros laboratorios. Se utilizaron las líneas celulares NIH 3T3, de origen fibroblástico y VERO, de origen epitelial. Esta última es una de las líneas celulares recomendada por la norma ISO 10993 para la evaluación de la citotoxicidad de los dispositivos médicos. La morfología y adhesión celular se evaluó mediante la utilización de microscopía electrónica de barrido. Los resultados mostraron que ambas líneas celulares fueron capaces de proliferar en presencia de HA, sin embargo solo células NIH 3T3 fueron capaces de adherirse y proliferar sobre la superficie de HA. Por lo tanto, la HA utilizada en estos ensayos no mostró efectos citotóxicos e incluso fue un sustrato adecuado para esta línea celular constituyendo un insumo factible para la fabricación de implantes.Fil: Comín, Romina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química. Ingeniería Biomédica; Argentina.Fil: Comín, Romina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Investigación Aplicada y Desarrollo; Argentina.Fil: Cid, Mariana. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química. Ingeniería Biomédica; Argentina.Fil: Cid, Mariana. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina.Fil: Reyna Musso, Laura. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Investigación Aplicada y Desarrollo; Argentina.Fil: Grinschpun, Luciano. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Ensayos. Centro de Vinculación Materiales y Tecnología; Argentina.Fil: Taborda, Ricardo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Laboratorio de Investigación Aplicada y Desarrollo; Argentina.Fil: Salvatierra, Nancy. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química. Ingeniería Biomédica; Argentina.Fil: Salvatierra, Nancy. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina.Otras Ingeniería Médic

Preparation of a three-dimensional extracellular matrix by decellularization of rabbit livers

Introduction: the availability of transplantable livers is not sufficient to fulfill the current demand for grafts, with the search for therapeutic alternatives having generated different lines of research, one of which is the use of decellularized three-dimensional biological matrices and subsequent cell seeding to obtain a functional organ. Objective: to produce a decellularization protocol from rabbit liver to generate a three-dimensional matrix. Methods: a combination of physical, chemical (Triton X-100 and SDS) and enzymatic agents to decellularize rabbit livers was used. After 68 h of retrograde perfusion, a decellularized translucent matrix was generated. To evaluate if the decellularization protocol was successful, with the extracellular matrix being preserved, we carried out histological (light microscopy and scanning electron microscopy) and biochemical (DNA quantification) studies. Results: the decellularization process was verified by macroscopic observation of the organ using macroscopic staining, which revealed a correct conservation of bile and vascular trees. A microscopic observation corroborated these macroscopic results, with the hematoxylin-eosin staining showing no cells or nuclear material and the presence of a portal triad. Wilde's staining demonstrated the conservation of reticulin fibers in the decellularized matrix. In addition, scanning electron microscopy revealed a preserved Glisson's capsule and a decellularized matrix, with the DNA quantification being less than 10 % in the decellularized liver compared to control. Finally, the time taken to develop the decellularization protocol was less than 96 hours. Conclusions: the proposed decellularization protocol was correct, and was verified by an absence of cells. The hepatic matrix had preserved vascular and bile ducts with a suitable three-dimensional architecture permitting further cell seeding