16 research outputs found

    MASSIV: Mass Assembly Survey with SINFONI in VVDS. V. The major merger rate of star-forming galaxies at 0.9 < z < 1.8 from IFS-based close pairs

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    We aim to measure the major merger rate of star-forming galaxies at 0.9 < z <1.8, using close pairs identified from integral field spectroscopy (IFS). We use the velocity field maps obtained with SINFONI/VLT on the MASSIV sample, selected from the star-forming population in the VVDS. We identify physical pairs of galaxies from the measurement of the relative velocity and the projected separation (r_p) of the galaxies in the pair. Using the well constrained selection function of the MASSIV sample we derive the gas-rich major merger fraction (luminosity ratio mu = L_2/L_1 >= 1/4), and, using merger time scales from cosmological simulations, the gas-rich major merger rate at a mean redshift up to z = 1.54. We find a high gas-rich major merger fraction of 20.8+15.2-6.8 %, 20.1+8.0-5.1 % and 22.0+13.7-7.3 % for close pairs with r_p <= 20h^-1 kpc in redshift ranges z = [0.94, 1.06], [1.2, 1.5) and [1.5, 1.8), respectively. This translates into a gas-rich major merger rate of 0.116+0.084-0.038 Gyr^-1, 0.147+0.058-0.037 Gyr^-1 and 0.127+0.079-0.042 Gyr^-1 at z = 1.03, 1.32 and 1.54, respectively. Combining our results with previous studies at z < 1, the gas-rich major merger rate evolves as (1+z)^n, with n = 3.95 +- 0.12, up to z = 1.5. From these results we infer that ~35% of the star-forming galaxies with stellar masses M = 10^10 - 10^10.5 M_Sun have undergone a major merger since z ~ 1.5. We develop a simple model which shows that, assuming that all gas-rich major mergers lead to early-type galaxies, the combined effect of gas-rich and dry mergers is able to explain most of the evolution in the number density of massive early-type galaxies since z ~ 1.5, with our measured gas-rich merger rate accounting for about two-thirds of this evolution.Comment: Published in Astronomy and Astrophysics, 24 pages, 30 figures, 2 tables. Appendix with the residual images from GALFIT added. Minor changes with respect to the initial versio

    Inflammation gene variants and susceptibility to albuminuria in the U.S. population: analysis in the Third National Health and Nutrition Examination Survey (NHANES III), 1991-1994

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    <p>Abstract</p> <p>Background</p> <p>Albuminuria, a common marker of kidney damage, serves as an important predictive factor for the progression of kidney disease and for the development of cardiovascular disease. While the underlying etiology is unclear, chronic, low-grade inflammation is a suspected key factor. Genetic variants within genes involved in inflammatory processes may, therefore, contribute to the development of albuminuria.</p> <p>Methods</p> <p>We evaluated 60 polymorphisms within 27 inflammatory response genes in participants from the second phase (1991-1994) of the Third National Health and Nutrition Examination Survey (NHANES III), a population-based and nationally representative survey of the United States. Albuminuria was evaluated as logarithm-transformed albumin-to-creatinine ratio (ACR), as ACR ≥ 30 mg/g, and as ACR above sex-specific thresholds. Multivariable linear regression and haplotype trend analyses were conducted to test for genetic associations in 5321 participants aged 20 years or older. Differences in allele and genotype distributions among non-Hispanic whites, non-Hispanic blacks, and Mexican Americans were tested in additive and codominant genetic models.</p> <p>Results</p> <p>Variants in several genes were found to be marginally associated (uncorrected P value < 0.05) with log(ACR) in at least one race/ethnic group, but none remained significant in crude or fully-adjusted models when correcting for the false-discovery rate (FDR). In analyses of sex-specific albuminuria, <it>IL1B </it>(rs1143623) among Mexican Americans remained significantly associated with increased odds, while <it>IL1B </it>(rs1143623), <it>CRP </it>(rs1800947) and <it>NOS3 </it>(rs2070744) were significantly associated with ACR ≥ 30 mg/g in this population (additive models, FDR-P < 0.05). In contrast, no variants were found to be associated with albuminuria among non-Hispanic blacks after adjustment for multiple testing. The only variant among non-Hispanic whites significantly associated with any outcome was <it>TNF </it>rs1800750, which failed the test for Hardy-Weinberg proportions in this population. Haplotypes within <it>MBL2</it>, <it>CRP</it>, <it>ADRB2, IL4R</it>, <it>NOS3</it>, and <it>VDR </it>were significantly associated (FDR-P < 0.05) with log(ACR) or albuminuria in at least one race/ethnic group.</p> <p>Conclusions</p> <p>Our findings suggest a small role for genetic variation within inflammation-related genes to the susceptibility to albuminuria. Additional studies are needed to further assess whether genetic variation in these, and untested, inflammation genes alter the susceptibility to kidney damage.</p

    Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

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    Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

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    Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

    Predictors of Progression in Albuminuria in the General Population:Results from the PREVEND Cohort

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    <p>Background: Urinary albumin excretion is known to be independently associated with progression of renal and cardiovascular disease. The aim of this study was to identify predictors for progression in albuminuria in the general population.</p><p>Methods: Data were used of the first 4 screening rounds of a community-based prospective cohort study (PREVEND). Included were 5,825 subjects that at baseline had no known renal disease or macroalbuminuria. Subjects were defined as having progressive albuminuria when they belonged to the quintile of subjects with highest absolute increase in urinary albumin excretion per year and a urinary albumin excretion during the last screening in which they participated of >= 150 mg/24 h. Change in urinary albumin excretion per year was calculated as last available urinary albumin excretion minus baseline UAE divided by follow-up time.</p><p>Results: During 9.3 years follow-up 132 subjects had progressive albuminuria. These subjects were significantly older, more often of male gender and had a worse cardiovascular risk profile. In a multivariable model, testing baseline values, significant predictors of progressive albuminuria were male gender (OR 2.23; p <0.001), age (OR 1.03; p <0.001), BMI (OR 1.06; p = 0.02) and baseline albuminuria (OR 5.71; p <0.001). Based on these findings a risk score was made to estimate a subject's risk for progressive albuminuria.</p><p>Conclusion: A high baseline albuminuria is by far the most important predictor of progressive albuminuria. Thus, screening for baseline albuminuria will be more important than screening for cardiovascular risk factors in order to identify subjects at risk for progressive albuminuria.</p>

    The effects of cannabidiolic acid and cannabidiol on contractility of the gastrointestinal tract of Suncus murinus

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    Cannabidiol (CBD) has been shown to inhibit gastrointestinal (GI) transit in pathophysiologic in vivo models, while having no effect in physiologic controls. The actions of the precursor of CBD, cannabidiolic acid (CBDA), have not been investigated in the GI tract. The actions of these phytocannabinoids on the contractility of the GI tract of Suncus murinus were investigated in the current study. The effects of CBDA and CBD in resting state and pre-contracted isolated intestinal segments, and on the contractile effects of carbachol and electrical field stimulation (EFS) on the intestines of S. murinus were examined. CBDA and CBD induced a reduction in resting tissue tension of isolated intestinal segments which was not blocked by the cannabinoid CB1 receptor antagonist, AM251, the CB2 receptor antagonist AM630, or tetrodotoxin. CBDA and CBD reduced the magnitude of contractions induced by carbachol and the tension of intestinal segments that were pre-contracted with potassium chloride. In tissues stimulated by EFS, CBDA inhibited contractions induced by lower frequencies (0.1–4.0 Hz) of EFS, while CBD inhibited contractions induced by higher frequencies (4.0–20.0 Hz) of EFS. The data suggest that CBDA and CBD have inhibitory actions on the intestines of S. murinus that are not neuronallymediated or mediated via CB1 or CB2 receptors

    Predictive Performance of Cardiovascular Disease Risk Prediction Algorithms in People Living With HIV

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    Immunogenetics and cellular immunology of bacterial infectious disease

    Factors associated with presenting late or with advanced HIV disease in the Netherlands, 1996 2014: Results from a national observational cohort

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    Objectives: Early testing for HIV and entry into care are crucial to optimise treatment outcomes of HIV-infected patients and to prevent spread of HIV. We examined risk factors for presentation with late or advanced disease in HIV-infected patients in the Netherlands. Methods: HIV-infected patients registered in care between January 1996 and June 2014 were selected from the ATHENA national observational HIV cohort. Risk factors for late presentation and advanced disease were analysed by multivariable logistic regression. Furthermore, geographical differences and time trends were examined. Results: Of 20 965 patients, 53% presented with latestage HIV infection, and 35% had advanced disease. Late presentation decreased from 62% (1996) to 42% (2013), while advanced disease decreased from 46% to 26%. Late presentation only declined significantly among men having sex with men (MSM; p <0.001), but not among heterosexual males (p=0.08) and females (p=0.73). Factors associated with late presentation were: heterosexual male (adjusted OR (aOR), 1.59; 95% CI 1.44 to 1.75 vs MSM), injecting drug use (2.00; CI 1.69 to 2.38), age .50 years (1.46; CI 1.33 to 1.60 vs 30.49 years), region of origin (South-East Asia 2.14; 1.80 to 2.54, sub-Saharan Africa 2.11; 1.88 to 2.36, Surinam 1.59; 1.37 to 1.84, Caribbean 1.31; 1.13 to 1.53, Latin America 1.23; 1.04 to 1.46 vs the Netherlands), and location of HIV diagnosis (hospital 3.27; 2.94 to 3.63, general practitioner 1.66; 1.50 to 1.83, antenatal screening 1.76; 1.38 to 2.34 vs sexually transmitted infection clinic). No association was found for socioeconomic status or level of urbanisation. Compared with Amsterdam, 2 regions had higher adjusted odds and 2 regions had lower odds of late presentation. Results were highly similar for advanced disease. Conclusions: Although the overall rate of late presentation is declining in the Netherlands, targeted programmes to reduce late HIV diagnoses remain needed for all risk groups, but should be prioritised for heterosexual males, migrant populations, people aged ≥50 years and certain regions in the Netherlands
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