RESUMO
Murine acquired immunodeficiency syndrome (MAIDS) is caused by exposure to murine leukemia virus and serves as a model to study human AIDS. In MAIDS-susceptible C57BL/6 mice, virus exposure leads to progressive immune deficiency, while resistant strains such as BALB/c recover from infection and develop protective immunity. The goal of this study was to identify early gene expression patterns that may be important in establishing this strain-specific differential response. Total RNA was isolated from spleens and pooled lymph nodes of both mouse strains at 3 and 7 days post virus infection. The complementary DNA generated from this RNA was hybridized to mouse oligonucleotide DNA microarrays using a strategy that controlled for inherent variability and highlighted only virus-induced changes. Fluorescent intensities were normalized and analyzed for statistically significant differential expression between strains across both time points and lymphoid organs. The majority of the resistance-associated genes was identified at day 3 post-infection and demonstrated the highest fold differences between strains, while more susceptibility-associated sequences were seen at 7 days post-infection. Among the most highly differentially expressed sequences seen at the earlier time point were genes related to protein metabolism, especially serine proteases. Differential patterns of chemokine-related genes were observed at the later time point. The overall pattern of expression suggests strain-specific differences in proteases and chemokines within secondary lymphoid organs shortly after infection influence the likelihood of disease progression.
Assuntos
Vírus da Leucemia Murina/fisiologia , Sistema Linfático/metabolismo , Síndrome de Imunodeficiência Adquirida Murina/metabolismo , Animais , Perfilação da Expressão Gênica , Vírus da Leucemia Murina/imunologia , Linfonodos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Síndrome de Imunodeficiência Adquirida Murina/imunologia , Síndrome de Imunodeficiência Adquirida Murina/virologia , Análise de Sequência com Séries de Oligonucleotídeos , Especificidade da Espécie , Baço/metabolismo , Fatores de Tempo , Replicação ViralRESUMO
The inability to consistently achieve a passive fit with screw-retained implant prostheses is well documented in the literature. Cement-retained implant frameworks have been advocated for implant-retained fixed partial dentures. However, cement retention has not been routinely advocated for fixed-detachable hybrid prostheses. This article describes a method for fabricating a cement-retained fixed-detachable hybrid prosthesis. The advantages and disadvantages are discussed.