68 research outputs found

    Intrauterine Growth Restriction Is a Direct Consequence of Localized Maternal Uropathogenic Escherichia coli Cystitis

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    Despite the continually increasing rates of adverse perinatal outcomes across the globe, the molecular mechanisms that underlie adverse perinatal outcomes are not completely understood. Clinical studies report that 10% of pregnant women will experience a urinary tract infection (UTI) and there is an association of UTIs with adverse perinatal outcomes. We introduced bacterial cystitis into successfully outbred female mice at gestational day 14 to follow pregnancy outcomes and immunological responses to determine the mechanisms that underlie UTI-mediated adverse outcomes. Outbred fetuses from mothers experiencing localized cystitis displayed intrauterine growth restriction (20–80%) as early as 48 hours post-infection and throughout the remainder of normal gestation. Robust infiltration of cellular innate immune effectors was observed in the uteroplacental tissue following introduction of UTI despite absence of viable bacteria. The magnitude of serum proinflammatory cytokines is elevated in the maternal serum during UTI. This study demonstrates that a localized infection can dramatically impact the immunological status as well as the function of non-infected distal organs and tissues. This model can be used as a platform to determine the mechanism(s) by which proinflammatory changes occur between non-contiguous genitourinary organ

    Characteristics of facilities with specialized programming for drinking drivers and for other criminal justice involved clients: analysis of a national database

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    <p>Abstract</p> <p>Background</p> <p>Offering specialized programming at substance abuse treatment facilities can help diversify clientele and funding sources, potentially enhancing the facilities' ability to survive and/or expand. Past research has shown that facilities only offering specialized programming for driving under the influence/driving while intoxicated offenders (DUI) are predominately private-for-profit owned. As criminal justice populations, both DUI and other criminal justice offenders, comprise a large proportion of those in community-based substance abuse treatment knowing facilities' characteristics would be important for administrators and policymakers to consider when updating programming, training staff or expanding capacity to ensure efficient use of scarce resources. However, while such characteristics are known for DUI programs, they are not known for facilities offering specialized programming for other criminal justice offenders.</p> <p>Methods</p> <p>Analysis of the 2004 US National Survey of Substance Abuse Treatment Facilities.</p> <p>Results</p> <p>Almost half the facilities (48.2%) offered either DUI or other criminal justice specialized programming. These facilities were divided between those offering DUI specialized programming (17.7%), other criminal justice specialized programming (16.6%) and both types of programming (13.9%). Certain characteristics were independently associated with offering DUI specialized programming (private ownership, rural location, for profit status) or other criminal justice specialized programming (receiving public funds, urban location, region of country).</p> <p>Conclusion</p> <p>Offering specialized programming for DUI or other criminal justice offenders was common and associated with distinct characteristics. These observed associations may reflect the positioning of the facility to increase visibility, or diversify clientele and possibly funding streams or the decision of policymakers. As the criminal justice populations show no sign of decreasing and resources are scarce, the efficient use of resources demands policymakers recognize the prevalence of these specialized programming, join forces to examine them for efficacy, and explicitly incorporate these characteristics into strategies for workforce training and plans for treatment expansion.</p

    Assembly of the FtsZ cell division ring and the action of cell division inhibitors of E. coli

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    Intermediates in the assembly of the machinery required for bacterial septation have not been defined. The earliest known step in the assembly of the septation machinery is the formation of an FtsZ ring at midcell. While it is believed that this ring is formed from polymerization of FtsZ into microtubule-like structures, nothing is known about the mechanism of FtsZ assembly at midcell. This study describes a new system to evaluate FtsZ polymerization in the presence of cytoplasmic proteins. Size exclusion chromatography was used to determine that the polymerization of endogenous FtsZ within cytoplasmic extracts proceeds by cooperative incorporation of an FtsZ dimer into the growing oligomer. These oligomers were stable in the absence of GTP, suggesting that cytoplasmic molecules may aid in the polymerization of FtsZ or may alter the GTPase activity of FtsZ. This hypothesis was supported by the observation that purified FtsZ displayed GTP-independent oligomerization when added to FtsZ-depleted cytoplasmic extracts. This assay can be used to identify and characterize molecules which regulate the assembly of the FtsZ ring at midcell. ^ SulA and MinCD are specific inhibitors of cell division in Eschehchia coli. In this study, size exclusion chromatography was used to determine the effect of the SulA and MinCD division inhibitors on the oligomerization state of endogenous FtsZ in cytoplasmic extracts, and immunofluorescence microscopy was used to determine the effect of SulA and MinCD on formation of FtsZ, FtsA and ZipA rings at potential division sites. SulA prevented formation of high molecular weight FtsZ polymers by interfering with FtsZ dimerization and subsequent oligomerization. In contrast, the MinCD division inhibitor did not prevent the oligomerization of FtsZ in cell extracts nor the formation of FtsZ and ZipA ring-structures in vivo. However, MinCD did prevent formation of FtsA rings. Increased expression of ftsA suppressed MinCD-induced division inhibition, but had no effect on SulA-induced division inhibition. These results indicate that MinCD blocks the assembly of the septation machinery at a later step than SulA, at the stage at which FtsA is added to the FtsZ ring.

    FIND: A new software tool and development platform for enhanced multicolor flow analysis

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    <p>Abstract</p> <p>Background</p> <p>Flow Cytometry is a process by which cells, and other microscopic particles, can be identified, counted, and sorted mechanically through the use of hydrodynamic pressure and laser-activated fluorescence labeling. As immunostained cells pass individually through the flow chamber of the instrument, laser pulses cause fluorescence emissions that are recorded digitally for later analysis as multidimensional vectors. Current, widely adopted analysis software limits users to manual separation of events based on viewing two or three simultaneous dimensions. While this may be adequate for experiments using four or fewer colors, advances have lead to laser flow cytometers capable of recording 20 different colors simultaneously. In addition, mass-spectrometry based machines capable of recording at least 100 separate channels are being developed. Analysis of such high-dimensional data by visual exploration alone can be error-prone and susceptible to unnecessary bias. Fortunately, the field of Data Mining provides many tools for automated group classification of multi-dimensional data, and many algorithms have been adapted or created for flow cytometry. However, the majority of this research has not been made available to users through analysis software packages and, as such, are not in wide use.</p> <p>Results</p> <p>We have developed a new software application for analysis of multi-color flow cytometry data. The main goals of this effort were to provide a user-friendly tool for automated gating (classification) of multi-color data as well as a platform for development and dissemination of new analysis tools. With this software, users can easily load single or multiple data sets, perform automated event classification, and graphically compare results within and between experiments. We also make available a simple plugin system that enables researchers to implement and share their data analysis and classification/population discovery algorithms.</p> <p>Conclusions</p> <p>The <b>FIND </b>(Flow Investigation using N-Dimensions) platform presented here provides a powerful, user-friendly environment for analysis of Flow Cytometry data as well as providing a common platform for implementation and distribution of new automated analysis techniques to users around the world.</p

    Maturation of Intracellular Escherichia coli Communities Requires SurA

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    Escherichia coli is the most common cause of community-acquired urinary tract infection (UTI). During murine cystitis, uropathogenic E. coli (UPEC) utilizes type 1 pili to bind and invade superficial bladder epithelial cells. UPEC then replicates within to form intracellular bacterial communities (IBCs), a process whose genetic determinants are as yet undefined. In this study, we investigated the role of SurA in the UPEC pathogenic cascade. SurA is a periplasmic prolyl isomerase/chaperone that facilitates outer membrane protein biogenesis and pilus assembly in E. coli. Invasion into bladder epithelial cells was disproportionately reduced when surA was genetically disrupted in the UPEC strain UTI89, demonstrating that binding alone is not sufficient for invasion. In a murine cystitis model, UTI89 surA::kan was unable to persist in the urinary tract. Complementation of UTI89 surA::kan with a plasmid (pDH15) containing surA under the control of an arabinose-inducible promoter restored in vivo binding and invasion events. However, the absence of arabinose within the mouse bladder resulted in depletion of SurA after invasion of the bacteria into the superficial epithelial cells. Under these conditions, invasion by UTI89/pDH15 surA::kan was normal, but in contrast to UTI89, UTI89/pDH15 surA::kan formed intracellular collections that contained fewer bacteria, were loosely organized, and lacked the normal transition to a densely packed, coccoid morphology. Our data argue that SurA is required within bladder epithelial cells for UPEC to undergo the morphological changes that underlie IBC maturation and completion of the UTI pathogenic cascade

    Suppression of Bladder Epithelial Cytokine Responses by Uropathogenic Escherichia coli

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    Urinary tract infections are most commonly caused by uropathogenic strains of Escherichia coli (UPEC), which invade superficial bladder epithelial cells via a type 1 pilus-dependent mechanism. Inside these epithelial cells, UPEC organisms multiply to high numbers to form intracellular bacterial communities, allowing them to avoid immune detection. Bladder epithelial cells produce interleukin-6 (IL-6) and IL-8 in response to laboratory strains of E. coli in vitro. We investigated the ability of UPEC to alter epithelial cytokine signaling by examining the in vitro responses of bladder epithelial cell lines to the cystitis strains UTI89 and NU14. The cystitis strains induced significantly less IL-6 than did the laboratory E. coli strain MG1655 from 5637 and T24 bladder epithelial cells. The cystitis strains also suppressed epithelial cytokine responses to exogenous lipopolysaccharide (LPS) and to laboratory E. coli. We found that insertional mutations in the rfa and rfb operons and in the surA gene all abolished the ability of UTI89 to suppress cytokine induction. The rfa and rfb operons encode LPS biosynthetic genes, while surA encodes a periplasmic cis-trans prolyl isomerase important in the biogenesis of outer membrane proteins. We conclude that, in this in vitro model system, cystitis strains of UPEC have genes encoding factors that suppress proinflammatory cytokine production by bladder epithelial cells
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