192 research outputs found

    The sustainability challenge of meeting carbon dioxide targets in Europe by 2020

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    Final draft version (post-refereeing). Archived with permission from Elsevier.Following the Kyoto Protocol, the European Union obligated itself to lower its greenhouse gas (GHG) emissions 20% below their 1990 level, by the year 2020. Carbon dioxide is the major GHG. To fulfill this obligation, the nations must meet the sustainability challenge of countering rising population plus affluence with the dematerialization of less energy per GDP plus the decarbonization of less carbon per energy. To test the feasibility of meeting the challenge, we analyzed carbon dioxide emission during 1993–2004. Although emissions in the entire Union grew only by an average of 0.31% per year, emissions and their drivers varied markedly among the 27 member states. Dematerialization and decarbonization did occur, but not enough to offset the slight population growth plus rapidly increasing affluence. To fulfill its obligation in the next 12 years, the EU27 would have to counter its increasing population and affluence by a combined dematerialization and decarbonization 1.9–2.6 times faster than during 1993–2004. Hence, fulfilling its obligation by addressing fossil carbon emissions alone is very unlikely

    Evaluation and optimization of a commercial enzyme linked immunosorbent assay for detection of Chlamydophila pneumoniae IgA antibodies

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    <p>Abstract</p> <p>Background</p> <p>Serologic diagnosis of <it>Chlamydophila pneumoniae </it>(Cpn) infection routinely involves assays for the presence of IgG and IgM antibodies to Cpn. Although IgA antibodies to Cpn have been found to be of interest in the diagnosis of chronic infections, their significance in serological diagnosis remains unclear. The microimmunofluorescence (MIF) test is the current method for the measurement of Cpn antibodies. While commercial enzyme linked immunosorbent assays (ELISA) have been developed, they have not been fully validated. We therefore evaluated and optimized a commercial ELISA kit, the SeroCP IgA test, for the detection of Cpn IgA antibodies.</p> <p>Methods</p> <p>Serum samples from 94 patients with anti-Cpn IgG titers ≥ 256 (study group) and from 100 healthy blood donors (control group) were tested for the presence of IgA antibodies to Cpn, using our in-house MIF test and the SeroCP IgA test. Two graph receiver operating characteristic (TG-ROC) curves were created to optimize the cut off given by the manufacturer.</p> <p>Results</p> <p>The MIF and SeroCP IgA tests detected Cpn IgA antibodies in 72% and 89%, respectively, of sera from the study group, and in 9% and 35%, respectively, of sera from the control group. Using the MIF test as the reference method and the cut-off value of the ELISA test specified by the manufacturer for seropositivity and negativity, the two tests correlated in 76% of the samples, with an agreement of Ƙ = 0.54. When we applied the optimized cut-off value using TG-ROC analysis, 1.65, we observed better concordance (86%) and agreement (0.72) between the MIF and SeroCP IgA tests.</p> <p>Conclusion</p> <p>Use of TG-ROC analysis may help standardize and optimize ELISAs, which are simpler, more objective and less time consuming than the MIF test. Standardization and optimization of commercial ELISA kits may result in better performance.</p

    Tissue MicroArray (TMA) analysis of normal and persistent Chlamydophila pneumoniae infection

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    BACKGROUND: Chlamydophila pneumoniae infection has been implicated as a potential risk factor for atherosclerosis, however the mechanism leading to persistent infection and its role in the disease process remains to be elucidated. METHODS: We validated the use of tissue microarray (TMA) technology, in combination with immunohistochemistry (IHC), to test antibodies (GroEL, GroES, GspD, Ndk and Pyk) raised against differentially expressed proteins under an interferon-gamma (IFN-γ) induced model of chlamydial persistence. RESULTS: In the cell pellet array, we were able to identify differences in protein expression patterns between untreated and IFN-γ treated samples. Typical, large chlamydial inclusions could be observed in the untreated samples with all antibodies, whereas the number of inclusions were decreased and were smaller and atypical in shape in the IFN-γ treated samples. The staining results obtained with the TMA method were generally similar to the changes observed between normal and IFN-γ persistence using proteomic analysis. Subsequently, it was shown in a second TMA including archival atheromatous heart tissues from 12 patients undergoing heart transplantation, that GroEL, GroES, GspD and Pyk were expressed in atheromatous heart tissue specimens as well, and were detectable morphologically within lesions by IHC. CONCLUSION: TMA technology proved useful in documenting functional proteomics data with the morphologic distribution of GroEL, GroES, GspD, Ndk and Pyk within formalin-fixed, paraffin-embedded cell pellets and tissues from patients with severe coronary atherosclerosis. The antibodies GroEL and GroES, which were upregulated under persistence in proteomic analysis, displayed positive reaction in atheromatous heart tissue from 10 out of 12 patients. These may be useful markers for the detection of persistent infection in vitro and in vivo

    Pathogen Sensing Pathways in Human Embryonic Stem Cell Derived-Endothelial Cells: Role of NOD1 Receptors.

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    Human embryonic stem cell-derived endothelial cells (hESC-EC), as well as other stem cell derived endothelial cells, have a range of applications in cardiovascular research and disease treatment. Endothelial cells sense Gram-negative bacteria via the pattern recognition receptors (PRR) Toll-like receptor (TLR)-4 and nucleotide-binding oligomerisation domain-containing protein (NOD)-1. These pathways are important in terms of sensing infection, but TLR4 is also associated with vascular inflammation and atherosclerosis. Here, we have compared TLR4 and NOD1 responses in hESC-EC with those of endothelial cells derived from other stem cells and with human umbilical vein endothelial cells (HUVEC). HUVEC, endothelial cells derived from blood progenitors (blood outgrowth endothelial cells; BOEC), and from induced pluripotent stem cells all displayed both a TLR4 and NOD1 response. However, hESC-EC had no TLR4 function, but did have functional NOD1 receptors. In vivo conditioning in nude rats did not confer TLR4 expression in hESC-EC. Despite having no TLR4 function, hESC-EC sensed Gram-negative bacteria, a response that was found to be mediated by NOD1 and the associated RIP2 signalling pathways. Thus, hESC-EC are TLR4 deficient but respond to bacteria via NOD1. This data suggests that hESC-EC may be protected from unwanted TLR4-mediated vascular inflammation, thus offering a potential therapeutic advantage

    Association of circulating Chlamydia pneumoniae DNA with cardiovascular disease: a systematic review

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    BACKGROUND: Chlamydia pneumoniae antigens, nucleic acids, or intact organisms have been detected in human atheroma. However, the presence of antibody does not predict subsequent cardiovascular (CV) events. We performed a systematic review to determine whether the detection of C. pneumoniae DNA in peripheral blood mononuclear cells (PBMC) was associated with CV disease. METHODS: We sought studies of C. pneumoniae DNA detection in PBMC by polymerase chain reaction (PCR) among patients with CV disease or other clinical conditions. We pooled studies in which CV patients were compared with non-diseased controls. We analyzed differences between studies by meta-regression, to determine which epidemiological and technical characteristics were associated with higher prevalence. RESULTS: Eighteen relevant studies were identified. In nine CV studies with control subjects, the prevalence of circulating C. pneumoniae DNA was 252 of 1763 (14.3%) CV patients and 74 of 874 (8.5%) controls, for a pooled odds ratio of 2.03 (95% CI: 1.34, 3.08, P < 0.001). Prevalence was not adjusted for CV risk factors. Current smoking status, season, and age were associated with C. pneumoniae DNA detection. High prevalence (>40%) was found in patients with cardiac, vascular, chronic respiratory, or renal disease, and in blood donors. Substantial differences between studies were identified in methods of sampling, extraction, and PCR targets. CONCLUSIONS: C. pneumoniae DNA detection was associated with CV disease in unadjusted case-control studies. However, adjustment for potentially confounding measures such as smoking or season, and standardization of laboratory methods, are needed to confirm this association

    Rac1 Regulates the NLRP3 Inflammasome Which Mediates IL-1beta Production in Chlamydophila pneumoniae Infected Human Mononuclear Cells

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    Chlamydophila pneumoniae causes acute respiratory tract infections and has been associated with development of asthma and atherosclerosis. The production of IL-1β, a key mediator of acute and chronic inflammation, is regulated on a transcriptional level and additionally on a posttranslational level by inflammasomes. In the present study we show that C. pneumoniae-infected human mononuclear cells produce IL-1β protein depending on an inflammasome consisting of NLRP3, the adapter protein ASC and caspase-1. We further found that the small GTPase Rac1 is activated in C. pneumoniae-infected cells. Importantly, studies with specific inhibitors as well as siRNA show that Rac1 regulates inflammasome activation in C. pneumoniae-infected cells. In conclusion, C. pneumoniae infection of mononuclear cells stimulates IL-1β production dependent on a NLRP3 inflammasome-mediated processing of proIL-1β which is controlled by Rac1

    The importance of disease associations and concomitant therapy for the long-term management of psoriasis patients

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    It is well established that several inflammatory-type conditions, such as arthritis, diabetes, cardiovascular disease, and irritable bowel disease exist comorbidly and at an increased incidence in patients with psoriasis. Psoriasis and other associated diseases are thought to share common inflammatory pathways. Conditions such as these, with similar pathogenic mechanisms involving cytokine dysregulation, are referred to as immune-mediated inflammatory diseases (IMIDs). Considerable evidence for the genetic basis of cormobidities in psoriasis exists. The WHO has reported that the occurrence of chronic diseases, including IMIDs, are a rising global burden. In addition, conditions linked with psoriasis have been associated with increasing rates of considerable morbidity and mortality. The presence of comorbid conditions in psoriasis patients has important implications for clinical management. QoL, direct health care expenditures and pharmacokinetics of concomitant therapies are impacted by the presence of comorbid conditions. For example, methotrexate is contraindicated in hepatic impairment, while patients on ciclosporin should be monitored for kidney function. In addition, some agents, such as beta blockers, lithium, synthetic antimalarial drugs, NSAIDs and tetracycline antibiotics, have been implicated in the initiation or exacerbation of psoriasis. Consequently, collaboration between physicians in different specialties is essential to ensuring that psoriasis treatment benefits the patient without exacerbating associated conditions

    Seroprevalence of 13 common pathogens in a rapidly growing U.S. minority population: Mexican Americans from San Antonio, TX

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    <p>Abstract</p> <p>Background</p> <p>Infection risks vary among individuals and between populations. Here we present information on the seroprevalence of 13 common infectious agents in a San Antonio-based sample of Mexican Americans. Mexican Americans represent the largest and most rapidly growing minority population in the U.S., and they are also considered a health disparities population.</p> <p>Methods</p> <p>We analyzed 1227 individuals for antibody titer to <it>Chlamydophila pneumoniae, Helicobacter pylori, Toxoplasma gondii</it>, cytomegalovirus, Epstein-Barr virus, herpes simplex virus-1, herpes simplex virus-2 (HSV-2), human herpesvirus-6 (HHV-6), varicella zoster virus (VZV), adenovirus-36, hepatitis A virus, and influenza A and B. Seroprevalence was examined as a function of sex, age, household income, and education.</p> <p>Results</p> <p>Seroprevalence estimates ranged from 9% for <it>T. gondii</it> to 92% for VZV, and were similar in both sexes except for HSV-2, which was more prevalent in women. Many pathogens exhibited a significant seroprevalence change over the examined age range (15-94 years), with 7 pathogens increasing and HHV-6 decreasing with age. Socioeconomic status significantly correlated with serostatus for some pathogens.</p> <p>Conclusions</p> <p>Our findings demonstrate substantial seroprevalence rates of these common infections in this sample of Mexican Americans from San Antonio, Texas that suffers from high rates of chronic diseases including obesity and type-2 diabetes.</p

    The Chlamydia psittaci Genome: A Comparative Analysis of Intracellular Pathogens

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    Chlamydiaceae are a family of obligate intracellular pathogens causing a wide range of diseases in animals and humans, and facing unique evolutionary constraints not encountered by free-living prokaryotes. To investigate genomic aspects of infection, virulence and host preference we have sequenced Chlamydia psittaci, the pathogenic agent of ornithosis.A comparison of the genome of the avian Chlamydia psittaci isolate 6BC with the genomes of other chlamydial species, C. trachomatis, C. muridarum, C. pneumoniae, C. abortus, C. felis and C. caviae, revealed a high level of sequence conservation and synteny across taxa, with the major exception of the human pathogen C. trachomatis. Important differences manifest in the polymorphic membrane protein family specific for the Chlamydiae and in the highly variable chlamydial plasticity zone. We identified a number of psittaci-specific polymorphic membrane proteins of the G family that may be related to differences in host-range and/or virulence as compared to closely related Chlamydiaceae. We calculated non-synonymous to synonymous substitution rate ratios for pairs of orthologous genes to identify putative targets of adaptive evolution and predicted type III secreted effector proteins.This study is the first detailed analysis of the Chlamydia psittaci genome sequence. It provides insights in the genome architecture of C. psittaci and proposes a number of novel candidate genes mostly of yet unknown function that may be important for pathogen-host interactions
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