725 research outputs found

    Challenges in predicting the change in the cumulative exposure of new tobacco and related products based on emissions and toxicity dose–response data

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    Funding: This work was funded by the Netherlands Food and Consumer Product Safety Authority (NVWA), Utrecht, the Netherlands. Project number 9.7.1Many novel tobacco products have been developed in recent years. Although many may emit lower levels of several toxicants, their risk in the long term remains unclear. We previously published a method for the exposure assessment of mixtures that can be used to compare the changes in cumulative exposure to carcinogens among tobacco products. While further developing this method by including more carcinogens or to explore its application to non-cancer endpoints, we encountered a lack of data that are required for better-substantiated conclusions regarding differences in exposure between products. In this special communication, we argue the case for more data on adverse health effects, as well as more data on the composition of the emissions from tobacco products. Such information can be used to identify significant changes in relevance to health using the cumulative exposure method with different products and to substantiate regulatory decisions.Publisher PDFPeer reviewe

    Olfactomedin 4 Serves as a Marker for Disease Severity in Pediatric Respiratory Syncytial Virus (RSV) Infection

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    Funding: Statement of financial support: The study was financially supported by the VIRGO consortium, an Innovative Cluster approved by the Netherlands Genomics Initiative and partially funded by the Dutch Government (BSIK 03012). The authors have indicated they have no personal financial relationships relevant to this article to disclose. Data Availability Statement: The data is accessible at http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE69606.Peer reviewedPublisher PD

    Different carbon isotope fractionation patterns during the development of phototrophic freshwater and marine biofilms

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    Natural phototrophic biofilms are influenced by a broad array of abiotic and biotic factors and vary over temporal and spatial scales. Different developmental stages can be distinguished and growth rates will vary due to the thickening of the biofilm, which is expected to lead to a limitation of light or mass transport. This study shows that variation in CO<sub>2(aq)</sub> availability leads to a fractionation shift and thereby affects δ<sup>13</sup>C signatures during biofilm development. For phototrophic freshwater biofilms it was found that the δ<sup>13</sup>C value became less negative with the thickening of the biofilm, while the opposite trend was found in marine biofilms. Modeling and pH profiling indicated that the trend in the freshwater system was caused by an increase in CO<sub>2(aq)</sub> limitation resulting in an increase of HCO<sub>3</sub><sup>−</sup> as C-source. The opposite trend in the marine system could be explained by a higher heterotrophic biomass and activity causing a higher carbon recycling and thereby lower δ<sup>13</sup>C values. We conclude that δ<sup>13</sup>C was more related to the net areal photosynthesis rate and carbon recycling, rather than to the growth rate of the biofilms

    The effects of treatment with chemotherapy on energy metabolism and inflammatory mediators in small-cell lung carcinoma.

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    A disturbed energy balance has been demonstrated in lung cancer patients. Both an enhanced resting energy expenditure (REE) and a decreased energy intake contribute to weight loss. Enhanced systemic levels of inflammatory mediators were found to be related to the enhanced REE in lung cancer. The aim of the present study was to investigate energy metabolism and systemic levels of inflammatory mediators in small-cell lung carcinoma (SCLC) patients before and after treatment with chemotherapy. Hypermetabolism and an enhanced inflammatory response have already been demonstrated in SCLC by our group before. Twelve newly diagnosed SCLC patients were consecutively included in the study. REE was measured by indirect calorimetry and body composition was determined by bioelectrical impedance (BIA) before and 1 month after treatment. To assess the inflammatory state the acute-phase proteins, C-reactive protein (CRP) and lipopolysaccharide-binding protein (LBP), both soluble tumour necrosis factor (TNF) receptors, (sTNF-R)-55 and sTNF-R75, and soluble intercellular adhesion molecule (sICAM)-1 were measured in plasma before and 1 month after treatment. CRP was assessed by turbidemetry, whereas the other inflammatory parameters were measured by enzyme-linked immunosorbent assay (ELISA). A significant reduction in REE was found irrespective of therapeutic outcome, whereas body weight and body composition remained stable. The acute-phase proteins CRP and LBP were reduced significantly after treatment with chemotherapy, whereas both sTNF receptors and sICAM-1 remained enhanced. No correlation, however, existed between the decrease in REE and the decrease in the acute-phase proteins. In conclusion, chemotherapeutic treatment attenuates the tumour-related metabolic derangements and acute-phase response

    Blockade of T-cell activation by dithiocarbamates involves novel mechanisms of inhibition of nuclear factor of activated T cells.

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    Dithiocarbamates (DTCs) have recently been reported as powerful inhibitors of NF-kappaB activation in a number of cell types. Given the role of this transcription factor in the regulation of gene expression in the inflammatory response, NF-kappaB inhibitors have been suggested as potential therapeutic drugs for inflammatory diseases. We show here that DTCs inhibited both interleukin 2 (IL-2) synthesis and membrane expression of antigens which are induced during T-cell activation. This inhibition, which occurred with a parallel activation of c-Jun transactivating functions and expression, was reflected by transfection experiments at the IL-2 promoter level, and involved not only the inhibition of NF-kappaB-driven reporter activation but also that of nuclear factor of activated T cells (NFAT). Accordingly, electrophoretic mobility shift assays (EMSAs) indicated that pyrrolidine DTC (PDTC) prevented NF-kappaB, and NFAT DNA-binding activity in T cells stimulated with either phorbol myristate acetate plus ionophore or antibodies against the CD3-T-cell receptor complex and simultaneously activated the binding of AP-1. Furthermore, PDTC differentially targeted both NFATp and NFATc family members, inhibiting the transactivation functions of NFATp and mRNA induction of NFATc. Strikingly, Western blotting and immunocytochemical experiments indicated that PDTC promoted a transient and rapid shuttling of NFATp and NFATc, leading to their accelerated export from the nucleus of activated T cells. We propose that the activation of an NFAT kinase by PDTC could be responsible for the rapid shuttling of the NFAT, therefore transiently converting the sustained transactivation of this transcription factor that occurs during lymphocyte activation, and show that c-Jun NH2-terminal kinase (JNK) can act by directly phosphorylating NFATp. In addition, the combined inhibitory effects on NFAT and NF-KB support a potential use of DTCs as immunosuppressants

    A novel germline mutation of PTEN associated with brain tumours of multiple lineages

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    We have identified a novel germline mutation in the PTEN tumour suppressor gene. The mutation was identified in a patient with a glioma, and turned out to be a heterozygous germline mutation of PTEN (Arg234Gln), without loss of heterozygosity in tumour DNA. The biological consequences of this germline mutation were investigated by means of transfection studies of the mutant PTEN molecule compared to wild-type PTEN. In contrast to the wild-type molecule, the mutant PTEN protein is not capable of inducing apoptosis, induces increased cell proliferation and leads to high constitutive PKB/Akt activation, which cannot be increased anymore by stimulation with insulin. The reported patient, in addition to glioma, had suffered from benign meningioma in the past but did not show any clinical signs of Cowden disease or other hereditary diseases typically associated with PTEN germline mutations. The functional consequences of the mutation in transfection studies are consistent with high proliferative activity. Together, these findings suggest that the Arg234Gln missense mutation in PTEN has oncogenic properties and predisposes to brain tumours of multiple lineages

    Rapid automatic assessment of microvascular density in sidestream dark field images

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    The purpose of this study was to develop a rapid and fully automatic method for the assessment of microvascular density and perfusion in sidestream dark field (SDF) images. We modified algorithms previously developed by our group for microvascular density assessment and introduced a new method for microvascular perfusion assessment. To validate the new algorithm for microvascular density assessment, we reanalyzed a selection of SDF video clips (n = 325) from a study in intensive care patients and compared the results to (semi-)manually found microvascular densities. The method for microvascular perfusion assessment (temporal SDF image contrast analysis, tSICA) was tested in several video simulations and in one high quality SDF video clip where the microcirculation was imaged before and during circulatory arrest in a cardiac surgery patient. We found that the new method for microvascular density assessment was very rapid (<30 s/clip) and correlated excellently with (semi-)manually measured microvascular density. The new method for microvascular perfusion assessment (tSICA) was shown to be limited by high cell densities and velocities, which severely impedes the applicability of this method in real SDF images. Hence, here we present a validated method for rapid and fully automatic assessment of microvascular density in SDF images. The new method was shown to be much faster than the conventional (semi-)manual method. Due to current SDF imaging hardware limitations, we were not able to automatically detect microvascular perfusion
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