Differential expression of cytokine genes and inducible nitric oxide synthase induced by opacity phenotype variants of Streptococcus pneumoniae during acute otitis media in the rat.

Phase variation in the colonial opacity phenotype of Streptococcus pneumoniae has been implicated as a factor in bacterial adherence, colonization, and invasion in the pathogenesis of pneumococcal otitis media (OM). The purpose of this study was to determine whether S. pneumoniae opacity variants influence the induction of gene expression for proinflammatory mediators in vivo using the rat model of OM. Both the opaque and transparent phenotype variants induced a significant up-regulation in gene expression for interleukin-1alpha (IL-1alpha), IL-1beta, IL-6, IL-10, tumor necrosis factor alpha, and inducible nitric oxide synthase (iNOS) compared to saline sham-inoculated controls at both 4 and 24 h postinoculation (P < 0.05 in all cases). Furthermore, whereas a significant difference in gene expression was evident for only IL-6 (greater following challenge with the opaque variant) and IL-1beta (greater following challenge with the transparent variant) at 4 h, by 24 h the opaque variant cohort demonstrated a significant increase in gene expression for IL-1alpha, IL-1beta, IL-6, IL-10, and iNOS relative to animals inoculated with the transparent phenotype variant (P < 0.05 in all cases). Enzyme-linked immunosorbent assay results confirmed the gene expression data as determined by real-time PCR. Moreover, the concentrations of the opaque variant in the middle ear lavage fluid were a full log higher than those of the transparent variant. The aforementioned results indicate that the opaque phenotype variant is more efficient at survival and multiplication within the middle ear space, resulting in the accumulation of more inflammatory cells and the enhanced expression and production of inflammatory mediators. However, when the data were normalized to account for differences in middle ear bacterial titers, it became apparent that the transparent variant of S. pneumoniae is a more potent inducer of inflammation, triggering the accumulation of more inflammatory cells and substantially greater fold increases in the expression and production of inflammatory mediators. Data from this study indicate that S. pneumoniae opacity variants influence the temporal mRNA expression of inflammatory mediators within the middle ear.

Expression of cytokine and chemokine genes by human middle ear epithelial cells induced by influenza A virus and Streptococcus pneumoniae opacity variants.

Real-time PCR and enzyme-linked immunosorbent assay were used to evaluate the ability of influenza A virus and Streptococcus pneumoniae opacity variants, either alone or in combination, to induce cytokine and chemokine genes in primary cultures of human middle ear epithelial (HMEE) cells. Following treatment with influenza A virus, the induction of gene expression, which occurred in a dose- and time-dependent manner, was strong for macrophage inflammatory protein 1 alpha (MIP-1 alpha) and MIP-1 beta; moderate for tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and IL-8; and weak for IL-1 beta and monocyte chemotactic peptide 1 (MCP-1). Except for TNF-alpha, all the gene products were detected in the cell culture supernatants. In contrast, infection of HMEE cells with S. pneumoniae alone induced low levels of mRNA expression of MIP-1 alpha and MIP-1 beta and did not significantly induce the transcription of the other cytokines and chemokines examined. However, both S. pneumoniae opacity variants increased mRNA expression of MIP-1 alpha, MIP-1 beta, IL-6, and MCP-1 in HMEE cells activated by a prior influenza A virus infection compared to levels in cells treated with either agent alone. Up-regulation of IL-6, IL-8, and MCP-1 mRNA expression and production by the virus in combination with opaque S. pneumoniae was two- to threefold higher than that induced by the virus combined with the transparent S. pneumoniae variant. These data indicate that the activation of HMEE cells by influenza A virus enhances the induction of cytokine and chemokine gene transcripts by S. pneumoniae and that this effect appears to be most pronounced when S. pneumoniae is in the opaque phase.

The crisis of the caregivers.

The crisis of near-drowning for the family and friends of the victim has been well documented. The emergency services personnel also are at risk for crisis as a result of the unique stressors they face because of their involvement with these critically injured young children. Mitchell's model for CISD is a pro-active and positive method for stress recognition, prevention, and reduction. It has particular application for those emergency services personnel who rescue and care for victims of water-related incidents, who are often young children. In this model, professionals are trained to recognize and respond to the stress-related needs of their colleagues. Through a combination of formal and informal sessions, a team of people assist the emergency services professional to explore their own thoughts and feelings toward a critical incident as a means of integrating those feelings into the person's repertoire of life experiences. This results in a reduction of stress and stress-related disorders and enables the emergency services professional to continue to function effectively and competently.