105 research outputs found

    Complete genome sequence of a Circovirus pigeon strain in lymphocyte-depleted bursa of Fabricius of a Common Raven (Corvus corax)

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    A necropsy was performed on a Common Raven (Corvus corax) presenting an opportunistic fungal respiratory infection and a bursal lymphoid depletion with inclusion bodies, suggestive of a circovirus infection. High-throughput sequencing of circular DNA in the bursa of Fabricius revealed a complete genome sequence of a Circovirus pigeon strain

    Risk of death among those awaiting treatment for HIV infection in Zimbabwe: adolescents are at particular risk.

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    INTRODUCTION: Mortality among HIV-positive adults awaiting antiretroviral therapy (ART) has previously been found to be high. Here, we compare adolescent pre-ART mortality to that of adults in a public sector HIV care programme in Bulawayo, Zimbabwe. METHODS: In this retrospective cohort study, we compared adolescent pre-ART outcomes with those of adults enrolled for HIV care in the same clinic. Adolescents were defined as those aged 10-19 at the time of registration. Comparisons of means and proportions were carried out using two-tailed sample t-tests and chi-square tests respectively, for normally distributed data, and the Mann-Whitney U-tests for non-normally distributed data. Loss to follow-up (LTFU) was defined as missing a scheduled appointment by three or more months. RESULTS: Between 2004 and 2010, 1382 of 1628 adolescents and 7557 of 11,106 adults who registered for HIV care met the eligibility criteria for ART. Adolescents registered at a more advanced disease stage than did adults (83% vs. 73% WHO stage III/IV, respectively, p<0.001), and the median time to ART initiation was longer for adolescents than for adults [21 (10-55) days vs. 15 (7-42) days, p<0.001]. Among the 138 adolescents and 942 adults who never commenced ART, 39 (28%) of adolescents and 135 (14%) of adults died, the remainder being LTFU. Mortality among treatment-eligible adolescents awaiting ART was significantly higher than among adults (3% vs. 1.8%, respectively, p=0.004). CONCLUSIONS: Adolescents present to ART services at a later clinical stage than adults and are at an increased risk of death prior to commencing ART. Improved and innovative HIV case-finding approaches and emphasis on prompt ART initiation in adolescents are urgently needed. Following registration, defaulter tracing should be used, whether or not ART has been commenced

    Carbonyl sulfide : comparing a mechanistic representation of the vegetation uptake in a land surface model and the leaf relative uptake approach

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    Land surface modellers need measurable proxies to constrain the quantity of carbon dioxide (CO2) assimilated by continental plants through photosynthesis, known as gross primary production (GPP). Carbonyl sulfide (COS), which is taken up by leaves through their stomates and then hydrolysed by photosynthetic enzymes, is a candidate GPP proxy. A former study with the ORCHIDEE land surface model used a fixed ratio of COS uptake to CO2 uptake normalised to respective ambient concentrations for each vegetation type (leaf relative uptake, LRU) to compute vegetation COS fluxes from GPP. The LRU approach is known to have limited accuracy since the LRU ratio changes with variables such as photosynthetically active radiation (PAR): while CO2 uptake slows under low light, COS uptake is not light limited. However, the LRU approach has been popular for COS-GPP proxy studies because of its ease of application and apparent low contribution to uncertainty for regional-scale applications. In this study we refined the COS-GPP relationship and implemented in ORCHIDEE a mechanistic model that describes COS uptake by continental vegetation. We compared the simulated COS fluxes against measured hourly COS fluxes at two sites and studied the model behaviour and links with environmental drivers. We performed simulations at a global scale, and we estimated the global COS uptake by vegetation to be -756 Gg S yr(-1) , in the middle range of former studies (-490 to -1335 Gg S yr(-1)). Based on monthly mean fluxes simulated by the mechanistic approach in ORCHIDEE, we derived new LRU values for the different vegetation types, ranging between 0.92 and 1.72, close to recently published averages for observed values of 1.21 for C-4 and 1.68 for C-3 plants. We transported the COS using the monthly vegetation COS fluxes derived from both the mechanistic and the LRU approaches, and we evaluated the simulated COS concentrations at NOAA sites. Although the mechanistic approach was more appropriate when comparing to high-temporal-resolution COS flux measurements, both approaches gave similar results when transporting with monthly COS fluxes and evaluating COS concentrations at stations. In our study, uncertainties between these two approaches are of secondary importance compared to the uncertainties in the COS global budget, which are currently a limiting factor to the potential of COS concentrations to constrain GPP simulated by land surface models on the global scale.Peer reviewe

    High prevalence of SARS-CoV-2 antibodies and low prevalence of SARS-CoV-2 RNA in cats recently exposed to human cases

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    Background The primary objective of this cross-sectional study, conducted in Québec and Bristish Columbia (Canada) between February 2021 and January 2022, was to measure the prevalence of viral RNA in oronasal and rectal swabs and serum antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) amongst cats living in households with at least one confirmed human case. Secondary objectives included a description of potential risk factors for the presence of SARS-CoV-2 antibodies and an estimation of the association between the presence of viral RNA in swabs as well as SARS-CoV-2 antibodies and clinical signs. Oronasal and rectal swabs and sera were collected from 55 cats from 40 households at most 15 days after a human case confirmation, and at up to two follow-up visits. A RT-qPCR assay and an ELISA were used to detect SARS-CoV-2 RNA in swabs and serum SARS-CoV-2 IgG antibodies, respectively. Prevalence and 95% Bayesian credibility intervals (BCI) were calculated, and associations were evaluated using prevalence ratio and 95% BCI obtained from Bayesian mixed log-binomial models. Results Nine (0.16; 95% BCI = 0.08–0.28) and 38 (0.69; 95% BCI = 0.56–0.80) cats had at least one positive RT-qPCR and at least one positive serological test result, respectively. No risk factor was associated with the prevalence of SARS-CoV-2 serum antibodies. The prevalence of clinical signs suggestive of COVID-19 in cats, mainly sneezing, was 2.12 (95% BCI = 1.03–3.98) times higher amongst cats with detectable viral RNA compared to those without. Conclusions We showed that cats develop antibodies to SARS-CoV-2 when exposed to recent human cases, but detection of viral RNA on swabs is rare, even when sampling occurs soon after confirmation of a human case. Moreover, cats with detectable levels of virus showed clinical signs more often than cats without signs, which can be useful for the management of such cases

    Heat shock protein 70-mediated sensitization of cells to apoptosis by Carboxyl-Terminal Modulator Protein

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    <p>Abstract</p> <p>Background</p> <p>The serine/threonine protein kinase B (PKB/Akt) is involved in insulin signaling, cellular survival, and transformation. Carboxyl-terminal modulator protein (CTMP) has been identified as a novel PKB binding partner in a yeast two-hybrid screen, and appears to be a negative PKB regulator with tumor suppressor-like properties. In the present study we investigate novel mechanisms by which CTMP plays a role in apoptosis process.</p> <p>Results</p> <p>CTMP is localized to mitochondria. Furthermore, CTMP becomes phosphorylated following the treatment of cells with pervanadate, an insulin-mimetic. Two serine residues (Ser37 and Ser38) were identified as novel <it>in vivo </it>phosphorylation sites of CTMP. Association of CTMP and heat shock protein 70 (Hsp70) inhibits the formation of complexes containing apoptotic protease activating factor 1 and Hsp70. Overexpression of CTMP increased the sensitivity of cells to apoptosis, most likely due to the inhibition of Hsp70 function.</p> <p>Conclusion</p> <p>Our data suggest that phosphorylation on Ser37/Ser38 of CTMP is important for the prevention of mitochondrial localization of CTMP, eventually leading to cell death by binding to Hsp70. In addition to its role in PKB inhibition, CTMP may therefore play a key role in mitochondria-mediated apoptosis by localizing to mitochondria.</p

    Integrative genomic and proteomic analyses identify targets for Lkb1 deficient metastatic lung tumors

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    SummaryIn mice, Lkb1 deletion and activation of KrasG12D results in lung tumors with a high penetrance of lymph node and distant metastases. We analyzed these primary and metastatic de novo lung cancers with integrated genomic and proteomic profiles and have identified gene and phosphoprotein signatures associated with Lkb1 loss and progression to invasive and metastatic lung tumors. These studies revealed that SRC is activated in Lkb1 deficient primary and metastatic lung tumors and that the combined inhibition of SRC, PI3K and MEK1/2 resulted in synergistic tumor regression. These studies demonstrate that integrated genomic and proteomic analyses can be used to identify signaling pathways that may be targeted for treatment
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