75 research outputs found

    Comparative analysis of the growth and biological activity of a respiratory and atheroma isolate of reveals strain-dependent differences in inflammatory activity and innate immune evasion

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    En el año 2010, como contraparte de los festejos del centenario de la Revolución mexicana, el poeta Jorge Esquinca invitó a treinta y cuatro poetas a participar en una antología titulada País de sombra y fuego. La relevancia de este ejercicio poético proviene de la pregunta que lo estructura: ¿Existe todavía en el vocablo Patria un núcleo generador de significado?A través del análisis de estos poemas y de los tópicos que prevalecen en ellos, es posible conocer el doloroso México que perciben los poetas mexicanos y la forma en que la poesía mexicana contemporánea del siglo XXI lo nombra.In 2010, as a counterpart to the festivities related to the 100th anniversary of the Mexican Revolution, the poet Jorge Esquinica invited thirty-four poets to participate in an anthology titled País de sombra y fuego. The relevance of this poetic exercise stems from the very question which gives it structure. Is the word Motherland still relevant in today's world?Through an analysis of these poems and the themes that prevail in them, it is possible to discover how these anthologized Mexican poets view their country nowadays and how they address its main issues.A l’any 2010, com a contrapart dels festejos del centenari de la Revolució mexicana, el poeta Jorge Esquinca va convidar trenta-quatre poetes a participar en una antologia titulada País de sombra y fuego. La rellevància d’aquest exercici poètic prové de la pregunta que l’estructura: existeix encara en el terme Pàtria un nucli generador de significat? A través de l’anàlisi d’aquests poemes i dels tòpics que prevalen en ells, és possible conèixer el dolorós Mèxic que perceben els poetes mexicans i la forma en què la poesia mexicana contamporània del segle XXI ho nombra

    Weekly SARS-CoV-2 screening of asymptomatic kindergarten to grade 12 students and staff helps inform strategies for safer in-person learning

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in K-12 schools was rare during in 2020-2021; few studies included Centers for Disease Control and Prevention (CDC)-recommended screening of asymptomatic individuals. We conduct a prospective observational study of SARS-CoV-2 screening in a mid-sized suburban public school district to evaluate the incidence of asymptomatic coronavirus disease 2019 (COVID-19), document frequency of in-school transmission, and characterize barriers and facilitators to asymptomatic screening in schools. Staff and students undergo weekly pooled testing using home-collected saliva samples. Identification of \u3e 1 case in a school prompts investigation for in-school transmission and enhancement of safety strategies. With layered mitigation measures, in-school transmission even before student or staff vaccination is rare. Screening identifies a single cluster with in-school staff-to-staff transmission, informing decisions about in-person learning. The proportion of survey respondents self-reporting comfort with in-person learning before versus after implementation of screening increases. Costs exceed $260,000 for assays alone; staff and volunteers spend 135-145 h per week implementing screening

    Specific Inflammatory Stimuli Lead to Distinct Platelet Responses in Mice and Humans

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    INTRODUCTION: Diverse and multi-factorial processes contribute to the progression of cardiovascular disease. These processes affect cells involved in the development of this disease in varying ways, ultimately leading to atherothrombosis. The goal of our study was to compare the differential effects of specific stimuli - two bacterial infections and a Western diet - on platelet responses in ApoE-/- mice, specifically examining inflammatory function and gene expression. Results from murine studies were verified using platelets from participants of the Framingham Heart Study (FHS; n = 1819 participants). METHODS: Blood and spleen samples were collected at weeks 1 and 9 from ApoE-/- mice infected with Porphyromonas gingivalis or Chlamydia pneumoniae and from mice fed a Western diet for 9 weeks. Transcripts based on data from a Western diet in ApoE-/- mice were measured in platelet samples from FHS using high throughput qRT-PCR. RESULTS:At week 1, both bacterial infections increased circulating platelet-neutrophil aggregates. At week 9, these cells individually localized to the spleen, while Western diet resulted in increased platelet-neutrophil aggregates in the spleen only. Microarray analysis of platelet RNA from infected or Western diet-fed mice at week 1 and 9 showed differential profiles. Genes, such as Serpina1a, Ttr, Fgg, Rpl21, and Alb, were uniquely affected by infection and diet. Results were reinforced in platelets obtained from participants of the FHS. CONCLUSION: Using both human studies and animal models, results demonstrate that variable sources of inflammatory stimuli have the ability to influence the platelet phenotype in distinct ways, indicative of the diverse function of platelets in thrombosis, hemostasis, and immunity

    Distinct gene signatures in aortic tissue from ApoE-/- mice exposed to pathogens or Western diet

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    BACKGROUND: Atherosclerosis is a progressive disease characterized by inflammation and accumulation of lipids in vascular tissue. Porphyromonas gingivalis (Pg) and Chlamydia pneumoniae (Cp) are associated with inflammatory atherosclerosis in humans. Similar to endogenous mediators arising from excessive dietary lipids, these Gram-negative pathogens are pro-atherogenic in animal models, although the specific inflammatory/atherogenic pathways induced by these stimuli are not well defined. In this study, we identified gene expression profiles that characterize P. gingivalis, C. pneumoniae, and Western diet (WD) at acute and chronic time points in aortas of Apolipoprotein E (ApoE-/-) mice. RESULTS: At the chronic time point, we observed that P. gingivalis was associated with a high number of unique differentially expressed genes compared to C. pneumoniae or WD. For the top 500 differentially expressed genes unique to each group, we observed a high percentage (76%) that exhibited decreased expression in P. gingivalis-treated mice in contrast to a high percentage (96%) that exhibited increased expression in WD mice. C. pneumoniae treatment resulted in approximately equal numbers of genes that exhibited increased and decreased expression. Gene Set Enrichment Analysis (GSEA) revealed distinct stimuli-associated phenotypes, including decreased expression of mitochondrion, glucose metabolism, and PPAR pathways in response to P. gingivalis but increased expression of mitochondrion, lipid metabolism, carbohydrate and amino acid metabolism, and PPAR pathways in response to C. pneumoniae; WD was associated with increased expression of immune and inflammatory pathways. DAVID analysis of gene clusters identified by two-way ANOVA at acute and chronic time points revealed a set of core genes that exhibited altered expression during the natural progression of atherosclerosis in ApoE-/- mice; these changes were enhanced in P. gingivalis-treated mice but attenuated in C. pneumoniae-treated mice. Notable differences in the expression of genes associated with unstable plaques were also observed among the three pro-atherogenic stimuli. CONCLUSIONS: Despite the common outcome of P. gingivalis, C. pneumoniae, and WD on the induction of vascular inflammation and atherosclerosis, distinct gene signatures and pathways unique to each pro-atherogenic stimulus were identified. Our results suggest that pathogen exposure results in dysregulated cellular responses that may impact plaque progression and regression pathways

    Enhanced Virulence of Chlamydia muridarum Respiratory Infections in the Absence of TLR2 Activation

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    Chlamydia trachomatis is a common sexually transmitted pathogen and is associated with infant pneumonia. Data from the female mouse model of genital tract chlamydia infection suggests a requirement for TLR2-dependent signaling in the induction of inflammation and oviduct pathology. We hypothesized that the role of TLR2 in moderating mucosal inflammation is site specific. In order to investigate this, we infected mice via the intranasal route with C. muridarum and observed that in the absence of TLR2 activation, mice had more severe disease, higher lung cytokine levels, and an exaggerated influx of neutrophils and T-cells into the lungs. This could not be explained by impaired bacterial clearance as TLR2-deficient mice cleared the infection similar to controls. These data suggest that TLR2 has an anti-inflammatory function in the lung during Chlamydia infection, and that the role of TLR2 in mucosal inflammation varies at different mucosal surfaces

    Plasmid-Cured Chlamydia caviae Activates TLR2-Dependent Signaling and Retains Virulence in the Guinea Pig Model of Genital Tract Infection

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    Loss of the conserved “cryptic” plasmid from C. trachomatis and C. muridarum is pleiotropic, resulting in reduced innate inflammatory activation via TLR2, glycogen accumulation and infectivity. The more genetically distant C. caviae GPIC is a natural pathogen of guinea pigs and induces upper genital tract pathology when inoculated intravaginally, modeling human disease. To examine the contribution of pCpGP1 to C. caviae pathogenesis, a cured derivative of GPIC, strain CC13, was derived and evaluated in vitro and in vivo. Transcriptional profiling of CC13 revealed only partial conservation of previously identified plasmid-responsive chromosomal loci (PRCL) in C. caviae. However, 2-deoxyglucose (2DG) treatment of GPIC and CC13 resulted in reduced transcription of all identified PRCL, including glgA, indicating the presence of a plasmid-independent glucose response in this species. In contrast to plasmid-cured C. muridarum and C. trachomatis, plasmid-cured C. caviae strain CC13 signaled via TLR2 in vitro and elicited cytokine production in vivo similar to wild-type C. caviae. Furthermore, inflammatory pathology induced by infection of guinea pigs with CC13 was similar to that induced by GPIC, although we observed more rapid resolution of CC13 infection in estrogen-treated guinea pigs. These data indicate that either the plasmid is not involved in expression or regulation of virulence in C. caviae or that redundant effectors prevent these phenotypic changes from being observed in C. caviae plasmid-cured strains

    Binding of Cryptococcus neoformans to heterologously expressed human complement receptors.

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    Previously, we demonstrated that monoclonal antibodies (MAb) directed against any of the three defined complement receptors (CR) for the third component of complement (CR1, CR3, and CR4) profoundly inhibited the binding of serum-opsonized Cryptococcus neoformans to monocyte-derived macrophages. These studies suggested either that a synergistic interaction between multiple CR was required for optimal binding of C. neoformans or that the MAb were exerting nonspecific effects (such as receptor coassociation). In the present studies, we took a novel approach to dissecting out the contributions of individual receptors to binding of a microbial pathogen. Chinese hamster ovary (CHO) cells stably transfected with human CR1, CR3, or CR4 were challenged with serum-opsonized C. neoformans. We found that CHO cells transfected with any of the three receptors bound C. neoformans, with the avidity of binding to CR3 being the greatest followed in decreasing order by CR1 and CR4. Following binding of C. neoformans to transfected CHO cells, most organisms remained surface attached only, although for each receptor a significant percentage (18.5 to 27.3%) of C. neoformans was internalized. Both C. neoformans and sheep erythrocytes that were selectively opsonized with the fragments of the third component of complement, C3b and iC3b, were bound preferentially by CHO cells transfected with CR1 and CR3, respectively. These data establish CR1, CR3, and CR4 as receptors independently capable of binding C. neoformans opsonized with fragments of C3. Moreover, our study demonstrates the usefulness of transfected cell lines as a powerful tool for identifying the contribution of individual receptors to the binding of a microbial pathogen

    Plasmid-Deficient Chlamydia muridarum

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    Response to Neisseria gonorrhoeae

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    Treatment of <i>Acanthamoeba</i> cysts with alcohols reduces excystation and trophozoite growth.

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    <p>Log plots of excystation and growth of <i>A</i>. <i>castellanii</i> MEI 0184 strain (A), <i>Acanthamoeba spp</i>. Shi (B) and Esbc4 (C) strains, and <i>A</i>. <i>byersi</i> (D). Compared to killing of trophozoites (<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005382#pntd.0005382.g002" target="_blank">Fig 2</a>), killing of cysts was much slower with 63% ethanol and much less effective with isopropanol. However, all four sets of <i>Acanthamoeba</i> cysts were rapidly killed by 80% ethanol.</p
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