1,558 research outputs found

    Comparison of Niskin vs. in situ approaches for analysis of gene expression in deep Mediterranean Sea water samples

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    Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 129 (2016): 213-222, doi:10.1016/j.dsr2.2014.10.020.Obtaining an accurate picture of microbial processes occurring in situ is essential for our understanding of marine biogeochemical cycles of global importance. Water samples are typically collected at depth and returned to the sea surface for processing and downstream experiments. Metatranscriptome analysis is one powerful approach for investigating metabolic activities of microorganisms in their habitat and which can be informative for determining responses of microbiota to disturbances such as the Deepwater Horizon oil spill. For studies of microbial processes occurring in the deep sea, however, sample handling, pressure, and other changes during sample recovery can subject microorganisms to physiological changes that alter the expression profile of labile messenger RNA. Here we report a comparison of gene expression profiles for whole microbial communities in a bathypelagic water column sample collected in the Eastern Mediterranean Sea using Niskin bottle sample collection and a new water column sampler for studies of marine microbial ecology, the Microbial Sampler – In Situ Incubation Device (MS-SID). For some taxa, gene expression profiles from samples collected and preserved 33 in situ were significantly different from potentially more stressful Niskin sampling and 34 preservation on deck. Some categories of transcribed genes also appear to be affected by sample 35 handling more than others. This suggests that for future studies of marine microbial ecology, 36 particularly targeting deep sea samples, an in situ sample collection and preservation approach 37 should be considered.This research was funded by NSF OCE-1061774 to VE and CT, NSF DBI-0424599 to CT and NSF OCE-0849578 to VE and colleague J. Bernhard. Cruise participation was partially supported by Deutsche Forschungsgemeinschaft (DFG) grant STO414/10-1 to T. Stoeck

    Orbit structure and (reversing) symmetries of toral endomorphisms on rational lattices

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    We study various aspects of the dynamics induced by integer matrices on the invariant rational lattices of the torus in dimension 2 and greater. Firstly, we investigate the orbit structure when the toral endomorphism is not invertible on the lattice, characterising the pretails of eventually periodic orbits. Next we study the nature of the symmetries and reversing symmetries of toral automorphisms on a given lattice, which has particular relevance to (quantum) cat maps.Comment: 29 pages, 3 figure

    Lung Function and Risk of Type 2 Diabetes and Fatal and Nonfatal Major Coronary Heart Disease Events: Possible Associations With Inflammation

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    OBJECTIVE - We prospectively examined the relationship between lung function and risk of type-2 diabetes and fatal and nonfatal coronary heart disease (CHD) events and investigated the hypothesis that inflammation may underlie these associations. RESEARCH DESIGN AND METHODS - A prospective study of 4,434 men aged 40-59 years with no history of cardiovascular disease (CHD or stroke) or diabetes drawn from general practices in 24 British towns and followed up for 20 years. RESULTS - There were 680 major CHD events (276 fatal, 404 nonfatal) and 256 incident type 2 diabetes during the 20 years follow-up. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEY1) but not FEV1-to-FVC ratio were significantly and inversely associated with incident type 2 diabetes and fatal CHD events (not nonfatal events) after adjustment for age, potential confounders, and metabolic risk factors. The adjusted relative risk (RR) for type 2 diabetes (Quartile 1 vs. Quartile 4) were 1.59 (1.07-2.56) and 1.74 (1.16-2.61) for FVC and FEV1, respectively (P = 0.03 and P = 0.04 for trend). The corresponding RR for fatal CHD were 1.48 (1.00-2.21) and 1.81 (1.19-2.76) (P = 0.002 and P = 0.0003 for trend). Lung function was significantly and inversely associated with C-reactive protein and interleukin-6; the inverse associations with type 2 diabetes for FVC and FEV1 were attenuated after further adjustment for these factors (P = 0.14 and P = 0.11 for trend) but remained significant for fatal CHD (P = 0.03 and P = 0.01, respectively). CONCLUSIONS - Restrictive rather than obstructive impairment of lung function is associated with incident type 2 diabetes (and fatal CHD) with both associations partially explained by traditional and metabolic risk factors and inflammation

    Mortality in GOLD stages of COPD and its dependence on symptoms of chronic bronchitis

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    BACKGROUND: The GOLD classification of COPD severity introduces a stage 0 (at risk) comprising individuals with productive cough and normal lung function. The aims of this study were to investigate total mortality risks in GOLD stages 0–4 with special focus on stage 0, and furthermore to assess the influence of symptoms of chronic bronchitis on mortality risks in GOLD stages 1–4. METHOD: Between 1974 and 1992, a total of 22 044 middle-aged individuals participated in a health screening, which included a spirometry as well as recording of respiratory symptoms and smoking habits. Individuals with comorbidity at baseline (diabetes, stroke, cancer, angina pectoris, or heart infarction) were excluded from the analyses. Hazard ratios (HR 95% CI) of total mortality were analyzed in GOLD stages 0–4 with individuals with normal lung function and without symptoms of chronic bronchitis as a reference group. HR:s in smoking individuals with symptoms of chronic bronchitis within the stages 1–4 were calculated with individuals with the same GOLD stage but without symptoms of chronic bronchitis as reference. RESULTS: The number of deaths was 3674 for men and 832 for women based on 352 324 and 150 050 person-years respectively. The proportion of smokers among men was 50% and among women 40%. Self reported comorbidity was present in 4.6% of the men and 6.6% of the women. Among smoking men, Stage 0 was associated with an increased mortality risk, HR; 1.65 (1.32–2.08), of similar magnitude as in stage 2, HR; 1.41 (1.31–1.70). The hazard ratio in stage 0 was significantly higher than in stage 1 HR; 1.13 (0.98–1.29). Among male smokers with stage 1; HR: 2.04 (1.34–3.11), and among female smokers with stage 2 disease; HR: 3.16 (1.38–7.23), increased HR:s were found in individuals with symptoms of chronic bronchitis as compared to those without symptoms of chronic bronchitis. CONCLUSION: Symptoms fulfilling the definition of chronic bronchitis were associated with an increased mortality risk among male smokers with normal pulmonary function (stage 0) and also with an increased risk of death among smoking individuals with mild to moderate COPD (stage 1 and 2)

    Marital status and occupation in relation to short-term case fatality after a first coronary event - a population based cohort

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    <p>Abstract</p> <p>Background</p> <p>Although marital status and low occupation level has been associated with mortality, the relationship with case fatality rates (CFR) after a coronary event (CE) is unclear. This study explored whether incidence of CE and short-term CFR differ between groups defined in terms of marital status and occupation, and if this could be explained by biological and life-style risk factors.</p> <p>Methods</p> <p>Population-based cohort study of 33,224 subjects (67% men), aged 27 to 61 years, without history of myocardial infarction, who were enrolled between 1974 and 1992. Incidence of CE, and CFR (death during the first day or within 28 days after CE, including out-of-hospital deaths) was examined over a mean follow-up of 21 years.</p> <p>Results</p> <p>A total of 3,035 men (6.0 per 1000 person-years) and 507 women (2.4 per 1000) suffered a first CE during follow-up. CFR (during the 1<sup>st </sup>day) was 29% in men and 23% in women. After risk factor adjustments, unmarried status in men, but not in women, was significantly associated with increased risk of suffering a CE [hazard ratios (HR) 1.10, 95% CI: 0.97-1.24; 1.42: 1.27-1.58 and 1.77: 1.31-2.40 for never married, divorced and widowed, respectively, compared to married]. Unmarried status, in both gender, was also related with an increased CFR (1<sup>st </sup>day), taking potential confounders into account (odds ratio (OR) 2.14, 95% CI: 1.63-2.81; 1.91: 1.50-2.43 and 1.49: 0.77-2.89 for never married, divorced and widowed, respectively, compared to married men. Corresponding figures for women was 2.32: 0.93-5.81; 1.87: 1.04-3.36 and 2.74: 1.03-7.28. No differences in CFR (1<sup>st </sup>day) were observed between occupational groups in neither gender.</p> <p>Conclusions</p> <p>In this population-based Swedish cohort, short-term CFR was significantly related to unmarried status in men and women. This relationship was not explained by biological-, life-style factors or occupational level.</p

    Immunoblot analysis of the seroreactivity to recombinant Borrelia burgdorferi sensu lato antigens, including VlsE, in the long-term course of treated patients with Erythema migrans

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    Objective: We evaluated whether immunoblotting is capable of substantiating the posttreatment clinical assessment of patients with erythema migrans ( EM), the hallmark of early Lyme borreliosis. Methods: In 50 patients, seroreactivity to different antigens of Borrelia burgdorferi sensu lato was analyzed by a recombinant immunoblot test (IB) in consecutive serum samples from a minimum follow-up period of 1 year. Antigens in the IgG test were decorin- binding protein A, internal fragment of p41 (p41i), outer surface protein C (OspC), p39, variable major protein-like sequence expressed (VlsE), p58 and p100; those in the IgM test were p41i, OspC and p39. Immune responses were correlated with clinical and treatment-related parameters. Results: Positive IB results were found in 50% before, in 57% directly after therapy and in 44% by the end of the follow-up for the IgG class, and in 36, 43 and 12% for the IgM class. In acute and convalescence phase sera, VlsE was most immunogenic on IgG testing 60 and 70%), and p41i (46 and 57%) and OspC (40 and 57%) for the IgM class. By the end of the follow-up, only the anti-p41i lgM response was significantly decreased to 24%. Conclusions: No correlation was found between IB results and treatment-related parameters. Thus, immunoblotting does not add to the clinical assessment of EM patients after treatment. Copyright (c) 2008 S. Karger AG, Basel

    Radiosensitising effect of electrochemotherapy with bleomycin in LPB sarcoma cells and tumors in mice

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    BACKGROUND: Bleomycin is poorly permeant but potent cytotoxic and radiosensitizing drug. The aim of the study was to evaluate whether a physical drug delivery system – electroporation can increase radiosensitising effect of bleomycin in vitro and in vivo. METHODS: LPB sarcoma cells and tumors were treated either with bleomycin, electroporation or ionizing radiation, and combination of these treatments. In vitro, response to different treatments was determined by colony forming assay, while in vivo, treatment effectiveness was determined by local tumor control (TCD(50)). Time dependence of partial oxygen pressure in LPB tumors after application of electric pulses was measured by electron paramagnetic oxyimetry. RESULTS: Electroporation of cells in vitro increased radiosensitising effect of bleomycin for 1.5 times, in vivo radiation response of tumors was enhanced by 1.9 fold compared to response of tumors that were irradiated only. Neither treatment of tumors with bleomycin nor application of electric pulses only, affected radiation response of tumors. Application of electric pulses to the tumors induced profound but transient reduction of tumor oxygenation. Although tumor oxygenation after electroporation partially restored at the time of irradiation, it was still reduced at the level of radiobiologically relevant hypoxia. CONCLUSION: Our study shows that application of electric pulses to cells and tumors increases radiosensitising effect of bleomycin. Furthermore, our results demonstrate that the radiobiologically relevant hypoxia induced by electroporation of tumors did not counteract the pronounced radiosensitising effect of electrochemotherapy with bleomycin

    Inflammation, insulin resistance, and diabetes-mendelian randomization using CRP haplotypes points upstream

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    Background Raised C-reactive protein (CRP) is a risk factor for type 2 diabetes. According to the Mendelian randomization method, the association is likely to be causal if genetic variants that affect CRP level are associated with markers of diabetes development and diabetes. Our objective was to examine the nature of the association between CRP phenotype and diabetes development using CRP haplotypes as instrumental variables. Methods and Findings We genotyped three tagging SNPs (CRP + 2302G &gt; A; CRP + 1444T &gt; C; CRP + 4899T &gt; G) in the CRP gene and measured serum CRP in 5,274 men and women at mean ages 49 and 61 y (Whitehall II Study). Homeostasis model assessment-insulin resistance (HOMA-IR) and hemoglobin A1c (HbA1c) were measured at age 61 y. Diabetes was ascertained by glucose tolerance test and self-report. Common major haplotypes were strongly associated with serum CRP levels, but unrelated to obesity, blood pressure, and socioeconomic position, which may confound the association between CRP and diabetes risk. Serum CRP was associated with these potential confounding factors. After adjustment for age and sex, baseline serum CRP was associated with incident diabetes (hazard ratio = 1.39 [95% confidence interval 1.29-1.51], HOMA-IR, and HbA1c, but the associations were considerably attenuated on adjustment for potential confounding factors. In contrast, CRP haplotypes were not associated with HOMA-IR or HbA1c (p=0.52-0.92). The associations of CRP with HOMA-IR and HbA1c were all null when examined using instrumental variables analysis, with genetic variants as the instrument for serum CRP. Instrumental variables estimates differed from the directly observed associations (p=0.007-0.11). Pooled analysis of CRP haplotypes and diabetes in Whitehall II and Northwick Park Heart Study II produced null findings (p=0.25-0.88). Analyses based on the Wellcome Trust Case Control Consortium (1,923 diabetes cases, 2,932 controls) using three SNPs in tight linkage disequilibrium with our tagging SNPs also demonstrated null associations. Conclusions Observed associations between serum CRP and insulin resistance, glycemia, and diabetes are likely to be noncausal. Inflammation may play a causal role via upstream effectors rather than the downstream marker CRP
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