RESUMEN
The CD19/CD21 complex is an essential B cell coreceptor that functions synergistically to enhance signaling through the B cell Ag receptor in response to T cell-dependent, complement-tagged Ags. In this study, we use a recombinant protein containing three tandemly arranged copies of C3d and the Ag hen egg lysozyme, shown to be a highly effective immunogen in vivo, to evaluate the role of the CD19/CD21 complex in Ag processing in B cells. Evidence is provided that coengagement of the CD19/CD21 complex results in more rapid and efficient production of antigenic peptide/class II complexes as compared with B cell Ag receptor-mediated processing alone. The CD19/CD21 complex does not itself target complement-tagged Ags for processing, but rather appears to influence B cell Ag processing through its signaling function. The ability of the CD19/CD21 complex to augment processing may be an important element of the mechanism by which the CD19/CD21 complex functions to promote B cell responses to T cell-dependent complement-tagged Ags in vivo.
Asunto(s)
Presentación de Antígeno/inmunología , Antígenos CD19/fisiología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Complemento C3d/metabolismo , Receptores de Complemento 3d/fisiología , Adyuvantes Inmunológicos/fisiología , Animales , Femenino , Antígenos de Histocompatibilidad Clase II/metabolismo , Ligandos , Sustancias Macromoleculares , Masculino , Ratones , Ratones Endogámicos CBA , Ratones Transgénicos , Muramidasa/metabolismo , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/metabolismo , Fosforilcolina/metabolismo , Pinocitosis/inmunología , Receptores de Antígenos de Linfocitos B/inmunología , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal/inmunología , Células Tumorales CultivadasRESUMEN
A confocal image analysis system is developed for automatic extraction of surface representation of biological structures. A visualization system is also developed to manipulate these surface representations and to obtain morphometrical parameters and provides a powerful tool for biomedical research such as microstructural characterization, morphogenesis, cell differentiation, tissue organization, and embryo development.
Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Rayos Láser , Microscopía Electrónica/métodos , Ultrasonografía , Células 3T3/citología , Algoritmos , Animales , Presentación de Datos , Sistemas de Administración de Bases de Datos , Aumento de la Imagen/métodos , Ratones , Redes Neurales de la Computación , Polen/ultraestructuraRESUMEN
The relative efficacies of cilofungin, amphotericin B and fluconazole were compared in the treatment of systemic Candida albicans infection in neutropenic mice. Thirty-one day survival rates were lowest for cilofungin (14.6%), intermediate for amphotericin B (37.6%) and highest for fluconazole (50.5%). Residual tissue infection in surviving animals was observed with all agents, but was heaviest with fluconazole, especially in the kidneys.
Asunto(s)
Anfotericina B/uso terapéutico , Antifúngicos/uso terapéutico , Candidiasis/tratamiento farmacológico , Fluconazol/uso terapéutico , Fungemia/tratamiento farmacológico , Péptidos Cíclicos , Anfotericina B/farmacocinética , Anfotericina B/farmacología , Animales , Antifúngicos/farmacocinética , Antifúngicos/farmacología , Candidiasis/mortalidad , Candidiasis/patología , Recuento de Colonia Microbiana , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Equinocandinas , Femenino , Fluconazol/farmacocinética , Fluconazol/farmacología , Fungemia/mortalidad , Fungemia/patología , Riñón/microbiología , Hígado/microbiología , Pulmón/microbiología , Ratones , Neutropenia/complicaciones , Péptidos/farmacocinética , Péptidos/farmacología , Péptidos/uso terapéutico , Bazo/microbiología , Tasa de SupervivenciaRESUMEN
An in vitro study was performed to determine the optimum amphotericin B concentration and exposure time required to kill various strains of Candida albicans in urine. This is a preliminary study to assess the feasibility of using amphotericin B bladder washout for localization of the site of candiduria. In broth kinetic killing studies, amphotericin B at a concentration of greater than 100 micrograms/ml produced almost complete killing of 5 x 10(5) CFU of C. albicans per ml within 1.5 to 2 h. In urine studies (with various pH values, osmolalities, and electrolyte concentrations), amphotericin B at a concentration of 200 micrograms/ml with a 2-h exposure time decreased fungal counts of 21 strains of C. albicans from 5 x 10(6) to less than 200 CFU/ml. Bladder washout with greater than or equal to 200 micrograms of amphotericin B per ml and a dwell time of 2 h can therefore sufficiently sterilize the bladder of yeasts and may be a useful localization test.