Renal Impairment and Cardiovascular Disease in HIV-positive Individuals; The D:A:D Study

BACKGROUND: While the association between renal impairment and cardiovascular disease (CVD) is well established in the general population, the association remains poorly understood in HIV-positive individuals. METHODS: Individuals with >2 estimated glomerular filtration rate (eGFRs) after 1/2/2004 were followed until CVD, death, last visit plus six months or 1/2/2015. CVD was defined as centrally validated myocardial infarction, stroke, invasive cardiovascular procedures or sudden cardiac death. RESULTS: During 8.0 years median follow-up (Interquartile range 5.4-8.9) 1,357 of 35,357 developed CVD (incidence 5.2/1000 person-years [95%confidence interval, CI [5.0-5.5]). Confirmed baseline eGFR and CVD were closely related with 1.8% [95%CI 1.6-2.0%] estimated to develop CVD at five years at eGFR>90 ml/min/1.73m(2), increasing to 21.1% [95%CI 6.6-35.6%] at eGFR<30 ml/min/1.73m(2) The strong univariate relationship between low current eGFR and CVD was primarily explained by increasing age in adjusted analyses, although all eGFRs<80 ml/min/1.73m(2) remained associated with 30-40% increased CVD rates and particular high rates at eGFR<30 ml/min/1.73m(2) (3.08 [95%CI 2.04-4.65]). CONCLUSIONS: Among HIV-positive individuals in a large contemporary cohort a strong relation between confirmed impaired eGFR and CVD was observed. This finding highlights the need for renal preventive measures and intensified monitoring for emerging CVD, in particular in older individuals with continuously low eGFR

Non-nucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy is associated with lower cell-associated hiv rna and dna levels as compared with therapy based on protease inhibitors

BACKGROUND: It remains unclear whether combination antiretroviral therapy (ART) regimens differ in their ability to fully suppress HIV replication. Here, we report the results of two crosssectional studies that compared levels of cell-associated (CA) HIV markers between individuals receiving suppressive ART containing either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI). METHODS: CA HIV unspliced RNA and total HIV DNA were quantified in two cohorts (n=100, n=124) of individuals treated with triple ART regimens consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) plus either a NNRTI or a PI. To compare CA HIV RNA and DNA levels between the regimens, we built multivariable models adjusting for age, gender, current and nadir CD4+ count, plasma viral load zenith, duration of virological suppression, NRTI backbone composition, low-level plasma HIV RNA detectability, and electronically-measured adherence to ART. RESULTS: In both cohorts, levels of CA HIV RNA and DNA strongly correlated (rho=0.70 and rho=0.54) and both markers were lower in NNRTI-treated than in PI-treated individuals. In the multivariable analysis, CA RNA in both cohorts remained significantly reduced in NNRTI-treated individuals (padj=0.02 in both cohorts), with a similar but weaker association between the ART regimen and total HIV DNA (padj=0.048 and padj=0.10). No differences in CA HIV RNA or DNA levels were observed between individual NNRTIs or individual PIs, but CA HIV RNA was lower in individuals treated with either nevirapine or efavirenz, compared to PI-treated individuals CONCLUSIONS: All current classes of antiretroviral drugs only prevent infection of new cells but do not inhibit HIV RNA transcription in long-lived reservoir cells. Therefore, these differences in CA HIV RNA and DNA levels by treatment regimen suggest that NNRTIs are more potent in suppressing HIV residual replication than PIs, which may result in a smaller viral reservoir size

Retinal glycoprotein enrichment by concanavalin a enabled identification of novel membrane autoantigen synaptotagmin-1 in equine recurrent uveitis.

Complete knowledge of autoantigen spectra is crucial for understanding pathomechanisms of autoimmune diseases like equine recurrent uveitis (ERU), a spontaneous model for human autoimmune uveitis. While several ERU autoantigens were identified previously, no membrane protein was found so far. As there is a great overlap between glycoproteins and membrane proteins, the aim of this study was to test whether pre-enrichment of retinal glycoproteins by ConA affinity is an effective tool to detect autoantigen candidates among membrane proteins. In 1D Western blots, the glycoprotein preparation allowed detection of IgG reactions to low abundant proteins in sera of ERU patients. Synaptotagmin-1, a Ca2+-sensing protein in synaptic vesicles, was identified as autoantigen candidate from the pre-enriched glycoprotein fraction by mass spectrometry and was validated as a highly prevalent autoantigen by enzyme-linked immunosorbent assay. Analysis of Syt1 expression in retinas of ERU cases showed a downregulation in the majority of ERU affected retinas to 24%. Results pointed to a dysregulation of retinal neurotransmitter release in ERU. Identification of synaptotagmin-1, the first cell membrane associated autoantigen in this spontaneous autoimmune disease, demonstrated that examination of tissue fractions can lead to the discovery of previously undetected novel autoantigens. Further experiments will address its role in ERU pathology

Relative role of short interfacial fingers and long internally driven streamers in convective flows below growing sea ice

Convective dynamics developing below growing sea ice are studied experimentally by freezing salt water from above in a quasi-two-dimensional Hele-Shaw cell. Observations of the convective processes are made with Schlieren and direct imaging systems, allowing visualization both under and within the growing ice. Buoyancy-driven flows are seen to develop under the ice layer via two different mechanisms: On one hand, brine diffuses out from the ice layer creating a denser boundary layer of enhanced salinity, which triggers boundary layer convection resulting in small-scale interfacial fingers. On the other hand, internal flow within brine drainage channels inside the ice is observed flushing out longer-scale convective streamers at given locations at the ice-water interface. Streamers descend in the bulk aqueous layer faster and for longer distances than fingers. Simulations confirm that, despite nonlinear interactions between fingers and streamers, the different speeds observed can be correlated to different density differences between the interfacial or internal rejection and the underlying bulk salt water. Estimates of relative mass fluxes through the interface by the two mechanisms suggest that, when streamers are active, the mass of salt rejected through the streamer pathway can be larger than the one expelled through the finger pathway. However, as fingers are maintained throughout the ice growth while the rejection from brine channels features an intermittent "on-off" behavior, there are certain periods of time when the mass flux of the two mechanisms is similar, but also some time intervals during which the flux due to interfacial short fingers becomes dominant.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Retrograde semaphorin-plexin signalling drives homeostatic synaptic plasticity.

Homeostatic signalling systems ensure stable but flexible neural activity and animal behaviour. Presynaptic homeostatic plasticity is a conserved form of neuronal homeostatic signalling that is observed in organisms ranging from Drosophila to human. Defining the underlying molecular mechanisms of neuronal homeostatic signalling will be essential in order to establish clear connections to the causes and progression of neurological disease. During neural development, semaphorin-plexin signalling instructs axon guidance and neuronal morphogenesis. However, semaphorins and plexins are also expressed in the adult brain. Here we show that semaphorin 2b (Sema2b) is a target-derived signal that acts upon presynaptic plexin B (PlexB) receptors to mediate the retrograde, homeostatic control of presynaptic neurotransmitter release at the neuromuscular junction in Drosophila. Further, we show that Sema2b-PlexB signalling regulates presynaptic homeostatic plasticity through the cytoplasmic protein Mical and the oxoreductase-dependent control of presynaptic actin. We propose that semaphorin-plexin signalling is an essential platform for the stabilization of synaptic transmission throughout the developing and mature nervous system. These findings may be relevant to the aetiology and treatment of diverse neurological and psychiatric diseases that are characterized by altered or inappropriate neural function and behaviour

Effect of Changes in Body Mass Index on the Risk of Cardiovascular Disease and Diabetes Mellitus in HIV-Positive Individuals: Results From the D:A:D Study

BACKGROUND: Weight gain is common among people with HIV once antiretroviral treatment (ART) is commenced. We assess the effect of changes in body mass index (BMI), from different baseline BMI levels, on the risk of cardiovascular disease (CVD) and diabetes mellitus (DM). METHODS: D:A:D participants receiving ART were followed from their first BMI measurement to the first of either CVD or DM event, or earliest of 1/2/2016 or 6 months after last follow-up. Participants were stratified according to their baseline BMI, and changes from baseline BMI were calculated for each participant. Poisson regression models were used to assess the effects of changes on BMI on CVD or DM events. RESULTS: There were 2,104 CVD and 1,583 DM events over 365,287 and 354,898 person years (rate: CVD 5.8/1000 (95% CI 5.5-6.0); DM 4.5/1000 (95% CI 4.2 - 4.7)). Participants were largely male (74%), baseline mean age of 40 years and median BMI of 23.0 (IQR: 21.0-25.3). Risk of CVD by change in BMI from baseline, stratified by baseline BMI strata showed little evidence of an increased risk of CVD with an increased BMI in any baseline BMI strata. An increase in BMI was associated with an increased risk of DM across all baseline BMI strata. CONCLUSIONS: While increases in BMI across all levels of baseline BMI were not associated with an increased risk of CVD, such changes were consistently associated with increased risk of DM. There was also some evidence of an increased risk of CVD with a decrease in BMI

Estimating the incidence of acute infectious intestinal disease in the community in the UK:A retrospective telephone survey

Objectives: To estimate the burden of intestinal infectious disease (IID) in the UK and determine whether disease burden estimations using a retrospective study design differ from those using a prospective study design. Design/Setting: A retrospective telephone survey undertaken in each of the four countries comprising the United Kingdom. Participants were randomly asked about illness either in the past 7 or 28 days. Participants: 14,813 individuals for all of whom we had a legible recording of their agreement to participate Outcomes: Self-reported IID, defined as loose stools or clinically significant vomiting lasting less than two weeks, in the absence of a known non-infectious cause. Results: The rate of self-reported IID varied substantially depending on whether asked for illness in the previous 7 or 28 days. After standardising for age and sex, and adjusting for the number of interviews completed each month and the relative size of each UK country, the estimated rate of IID in the 7-day recall group was 1,530 cases per 1,000 person-years (95% CI: 1135 – 2113), while in the 28-day recall group it was 533 cases per 1,000 person-years (95% CI: 377 – 778). There was no significant variation in rates between the four countries. Rates in this study were also higher than in a related prospective study undertaken at the same time. Conclusions: The estimated burden of disease from IID varied dramatically depending on study design. Retrospective studies of IID give higher estimates of disease burden than prospective studies. Of retrospective studies longer recall periods give lower estimated rates than studies with short recall periods. Caution needs to be exercised when comparing studies of self-reported IID as small changes in study design or case definition can markedly affect estimated rates

Non-nucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy is associated with lower cell-associated HIV RNA and DNA levels compared to protease inhibitor-based therapy

Background: It remains unclear whether combination antiretroviral therapy (ART) regimens differ in their ability to fully suppress human immunodeficiency virus (HIV) replication. Here, we report the results of two cross-sectional studies that compared levels of cell-associated (CA) HIV markers between individuals receiving suppressive ART containing either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI). Methods: CA HIV unspliced RNA and total HIV DNA were quantified in two cohorts (n = 100, n = 124) of individuals treated with triple ART regimens consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) plus either an NNRTI or a PI. To compare CA HIV RNA and DNA levels between the regimens, we built multivariable models adjusting for age, gender, current and nadir CD4+ count, plasma viral load zenith, duration of virological suppression, NRTI backbone composition, low-level plasma HIV RNA detectability, and electronically measured adherence to ART. Results: In both cohorts, levels of CA HIV RNA and DNA strongly correlated (rho = 0.70 and rho = 0.54) and both markers were lower in NNRTI-treated than in PI-treated individuals. In the multivariable analysis, CA RNA in both cohorts remained significantly reduced in NNRTI-treated individuals (padj = 0.02 in both cohorts), with a similar but weaker association between the ART regimen and total HIV DNA (padj = 0.048 and padj = 0.10). No differences in CA HIV RNA or DNA levels were observed between individual NNRTIs or individual PIs, but CA HIV RNA was lower in individuals treated with either nevirapine or efavirenz, compared to PI-treated individuals. Conclusions: All current classes of antiretroviral drugs only prevent infection of new cells but do not inhibit HIV RNA transcription in long-lived reservoir cells. Therefore, these differences in CA HIV RNA and DNA levels by treatment regimen suggest that NNRTIs are more potent in suppressing HIV residual replication than PIs, which may result in a smaller viral reservoir size

Reliance on habits at the expense of goal-directed control following dopamine precursor depletion

Rationale Dopamine is well known to play an important role in learning and motivation. Recent animal studies have implicated dopamine in the reinforcement of stimulus-response habits, as well as in flexible, goal-directed action. However, the role of dopamine in human action control is still not well understood. Objectives We present the first investigation of the effect of reducing dopamine function in healthy volunteers on the balance between habitual and goal-directed action control. Methods The dietary intervention of acute dietary phenylalanine and tyrosine depletion (APTD) was adopted to study the effects of reduced global dopamine function on action control. Participants were randomly assigned to either the APTD or placebo group (ns = 14) to allow for a between-subjects comparison of performance on a novel three-stage experimental paradigm. In the initial learning phase, participants learned to respond to different stimuli in order to gain rewarding outcomes. Subsequently, an outcome-devaluation test and a slips-of-action test were conducted to assess whether participants were able to flexibly adjust their behaviour to changes in the desirability of the outcomes. Results APTD did not prevent stimulus-response learning, nor did we find evidence for impaired response-outcome learning in the subsequent outcome-devaluation test. However, when goal-directed and habitual systems competed for control in the slips-of-action test, APTD tipped the balance towards habitual control. These findings were restricted to female volunteers. Conclusions We provide direct evidence that the balance between goal-directed and habitual control in humans is dopamine dependent. The results are discussed in light of gender differences in dopamine function and psychopathologies