Activated protein C increases sensitivity to vasoconstriction in rabbit Escherichia coli endotoxin-induced shock

INTRODUCTION: The aim of this study was to investigate the effects of activated protein C (aPC) on vascular function, endothelial injury, and haemostasis in a rabbit endotoxin-induced shock model. METHOD: This study included 22 male New Zealand rabbits weighing 2.5 to 3 kg each. In vitro vascular reactivity, endothelium CD31-PECAM1 immunohistochemistry, plasma coagulation factors and monocyte tissue factor (TF) expression were performed 5 days (D5) after onset of endotoxic shock (initiated by 0.5 mg/kg intravenous bolus of Escherichia coli lipopolysaccharide (LPS)) with or without treatment with aPC injected as an intravenous 2 mg/kg bolus 1 hour after LPS (LPS+aPC group and LPS group, respectively). RESULTS: LPS decreased the sensitivity to phenylephrine (PE) in aortic rings without endothelium (E-) when compared to E- rings from the control group (p < 0.05). This was abolished by N(G)-nitro-L-arginine methyl ester and not observed in E- rings from aPC-treated rabbits. Although aPC failed to decrease monocyte TF expression in endotoxinic animals at D5, aPC treatment restored the endothelium-dependent sensitivity in response to PE (2.0 ± 0.2 μM in rings with endothelium (E+) versus 1.0 ± 0.2 μM in E- rings (p < 0.05) in the LPS+aPC group versus 2.4 ± 0.3 μM in E+ rings versus 2.2 ± 0.2 μM in E- rings (p value not significant), in the LPS group). Endotoxin-induced de-endothelialisation was reduced by aPC at D5 (28.5 ± 2.3% in the LPS+aPC group versus 40.4 ± 2.4% in the LPS group, p < 0.05). CONCLUSION: These data indicate that aPC increased the sensitivity to a vasoconstrictor agent (PE) associated with restoration of endothelial modulation, and protected against endothelial histological injury in endotoxin-induced shock. It failed to inhibit TF expression at D5 after LPS injection

0312: Characterization of human valvular interstitial cells isolated from normal and fibrocalcified aortic valves

PurposeAortic Valve Stenosis (AVS) affects 2% to 6% of population over 65 years in industrialized countries. This atherosclerosis-like pathology involves Valve Interstitial Cell (VIC) proliferation and commitment to osteoblast- like cells. This prevalent cell type of aortic valve presents five identifiable phenotypes: embryonic progenitor endothelial/mesenchymal cells, progenitor, quiescent, activated and osteoblastic VICs. To study the pathophysiology of AVS, their in vitro cultures are frequently used. Our purpose is to characterize VICs isolated from normal and fibrocalcified human aortic valves and analyze their in vitro behavior.MethodsWe collected 5 normal and 5 fibrocalcified human aortic valves. VICs were isolated by collagenase digestion. Characterization is assessed at different passages (2 to 5) by immunofluorescence. Analyzed markers consist of progenitor cell markers (SSEA4, ABCG2, CD90, NG2 and OsteoBlast CaDHerin (OB-CDH)), fibroblast markers (vimentin and HSP47) and smooth muscle cell (SMC) marker (α-actin). By blue trypan and MTS, we compared the viability and proliferation of VICs in standard and starvation medium at 48 hours.ResultsIndependently of their origin, VICs express all progenitor cell markers. Fibroblasts markers are expressed twice more by pathological VICs and four times more for SMC marker. In standard medium, VICs viability is similar (96,7±2,4% vs 96,4±2,3% ; normal vs pathological ± SEM). Pathological VICs proliferate more than normal VICs (2,2±0,7 vs 1,6±0,4 ; OD/OD control). In starvation medium, viability is significantly reduced for pathological VICs (89,6±7,9% vs 76,5±5,3%) but still proliferate in opposition with normal VICs (1,7±0,6 vs 1,2±0,3).ConclusionAll VICs phenotypes are found in vitro with no culture selection but in different ratios according to their origin. These new data in VICs isolated from normal or pathological human aortic valves allow us to approve their use in vitro

060 Plasma aldosterone levels predict long-term clinical outcome after percutaneous coronary revascularization

The renin-angiotensin-aldosterone system is a major therapeutic target in coronary artery disease (CAD). Recent data suggest that plasma aldosterone has a high prognostic value in acute coronary syndrome (ACS). We tested whether plasma aldosterone could predict clinical outcome in patients undergoing scheduled percutaneous coronary revascularization (PCR).MethodsFrom June 2001 to September 2002, we included all consecutive patients referred to Lille's University Hospital for scheduled PCR. Blood samples were taken during the PCR. The primary endpoint was cardiac death throughout at least 12 months of follow-up.Results807 patients were included, with a mean age of 61 years. Most were men (78%), smokers (71%). 32% were diabetics, mean LVEF was 58±15% and 93% received stents. 50% had stable angina. The mean plasma aldosterone level was 25(13-45)pg/mL. BMI (p=0.003), NYHA class>1 (p=0.0001) and elevated baseline troponine (p=0.01) were associated with increased aldosterone level. Old age (p=0.0001), normal GFR (p=0.01) and betablockers (p=0.01) were associated with decreased aldosterone level. The mean follow-up was 14.9 months and there were 40 cardiac deaths during this period. In multivariate analysis, old age (HR=1.42, p=0.04), low LVEF (HR=1.58, p=0.001), diabetes mellitus (HR=2.2, p=0.04), a recent history of ACS (HR=3.23, p=0.02), high usCRP (HR=2.59, p=0.004) and high plasma aldosterone (HR=3.48, p=0.004) were independent predictors of cardiac mortality.ConclusionPlasma aldosterone level seems to have an independent prognostic value in patients referred for PCR and could be useful in determining the individual cardiovascular risk. Whether this is the result of direct deleterious effects (promotion of endothelial dysfunction, pro-fibrotic, pro-inflammatory and pro-thrombotic effects) or the marker of a global activation of the neuroendocrine system remains to be determined. However plasma aldosterone appears to be an attractive risk marker in CAD

Higher placental anti-inflammatory IL-10 cytokine expression in HIV-1 infected women receiving longer zidovudine prophylaxis associated with nevirapine

Placental cytokine balance may be critical for the control of mother-to-child transmission (MTCT) of HIV. We assessed whether the type and duration of antiretrovirals used for prevention of HIV-1-MTCT modified the inflammatory cytokine profile. We investigated the levels of cytokine expression in the placentas of 61 HIV-1-infected women who received zidovudine (ZDV) plus single dose nevirapine (SD-NVP) or ZDV only for prevention of MTCT. Placentas of 38 HIV-1-uninfected women were included as controls. All placentas were obtained after vaginal delivery. Levels of mRNA and cytokine expression were quantified using real-time PCR and ELISA, respectively, in placental explants and 24-hour culture supernatants and analyzed in relation to the women's characteristics and the type and duration of antiretroviral prophylaxis. HIV-1-infected and uninfected women did not show any differences in the expression of placental cytokine secretion except for a trend toward lower TNF-10 mRNA levels in HIV-1-infected women. Within the HIV-1-infected group, women who were exposed to a long duration of ZDV (>72 days) or received SD-NVP less than 5h prior to delivery, more frequently expressed detectable levels of IL-10 in their placentas (32% versus 7% (p = 0.01) and 32% versus 5% (p = 0.02), respectively). No infant was found to be HIV-1-infected. Our results showed a normalization of the placental cytokine balance in HIV-1-infected women receiving antiretroviral prophylaxis. Furthermore, the type and duration of antiretroviral prophylaxis have an impact on the placental anti-inflammatory IL-10 expression level, which may contribute to controlling HIV replication at the placental level, thus reducing MTCT of HIV-1.Fil: Pornprasert, Sakorn. Chiang Mai University; TailandiaFil: Mary, Jean-Yves. Université Paris Diderot - Paris 7; FranciaFil: Faye, Albert. Institut National de la Santé et de la Recherche Médicale; FranciaFil: Leechanachai, Pannee. Chiang Mai University; TailandiaFil: Limtrakul, Aram. Health Promotion Center Region; TailandiaFil: Rugpao, Sungwal. Chiang Mai University; TailandiaFil: Sirivatanapa, Pannee. Chiang Mai University; TailandiaFil: Gomuthbutra, Vorapin. Nakornping Hospital; TailandiaFil: Matanasaravoot, Wanmanee. Lamphun Hospital; TailandiaFil: Le Coer, Sophie. Institut National d’Etudes Démographiques; FranciaFil: Lallemant, Marc. Centre National de la Recherche Scientifique. Institut de Recherche pour le Développement; FranciaFil: Barré-Sinoussi, Françoise. Instituto Pasteur; FranciaFil: Menu, Elisabeth. Instituto Pasteur; FranciaFil: Ngo Giang Huong, Nicole. Centre National de la Recherche Scientifique. Institut de Recherche pour le Développement; FranciaFil: Ayouba, Ahidjo. Instituto Pasteur; FranciaFil: Chailert, Sanupong. Chiang Mai University; Tailandia. Instituto Pasteur; FranciaFil: Chaouat, Gérard. Institut National de la Santé et de la Recherche Médicale; FranciaFil: Derrien, Muriel. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Dolcini, Guillermina Laura. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Sanidad Animal y Medicina Preventiva. Laboratorio de Virología; Argentina. Instituto Pasteur; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Eteki, Nicole. Hôpital Central de Yaoundé. Maternité Principale; CamerúnFil: Kfutwah, Anfumbom Jude. Instituto Pasteur; FranciaFil: Kouo, Odette. Instituto Pasteur; FranciaFil: Lemen, Brigitte. Instituto Pasteur; FranciaFil: Abal, Facundo Juan Pablo. Instituto Pasteur; FranciaFil: Nerrienet, Eric. Instituto Pasteur; FranciaFil: Njinku, Bernadette. Instituto Pasteur; FranciaFil: Scarlatti, Gabriella. Suan Dok Hospital; TailandiaFil: Tejiokem, Mathurin. Centre Pasteur du Cameroun; CamerúnFil: Téné, Gilbert. No especifíca

Increasing crop heterogeneity enhances multitrophic diversity across agricultural regions

International audienceAgricultural landscape homogenization has detrimental effects on biodiversity and key ecosystem services. Increasing agricultural landscape heterogeneity by increasing seminatural cover can help to mitigate biodiversity loss. However, the amount of seminatural cover is generally low and difficult to increase in many intensively managed agricultural landscapes. We hypothesized that increasing the heterogeneity of the crop mosaic itself (hereafter “crop heterogeneity”) can also have positive effects on biodiversity. In 8 contrasting regions of Europe and North America, we selected 435 landscapes along independent gradients of crop diversity and mean field size. Within each landscape, we selected 3 sampling sites in 1, 2, or 3 crop types. We sampled 7 taxa (plants, bees, butterflies, hoverflies, carabids, spiders, and birds) and calculated a synthetic index of multitrophic diversity at the landscape level. Increasing crop heterogeneity was more beneficial for multitrophic diversity than increasing seminatural cover. For instance, the effect of decreasing mean field size from 5 to 2.8 ha was as strong as the effect of increasing seminatural cover from 0.5 to 11%. Decreasing mean field size benefited multitrophic diversity even in the absence of seminatural vegetation between fields. Increasing the number of crop types sampled had a positive effect on landscape-level multitrophic diversity. However, the effect of increasing crop diversity in the landscape surrounding fields sampled depended on the amount of seminatural cover. Our study provides large-scale, multitrophic, cross-regional evidence that increasing crop heterogeneity can be an effective way to increase biodiversity in agricultural landscapes without taking land out of agricultural production

Quantitative Mass Spectrometry Analysis Using PAcIFIC for the Identification of Plasma Diagnostic Biomarkers for Abdominal Aortic Aneurysm

BACKGROUND: Abdominal aortic aneurysm (AAA) is characterized by increased aortic vessel wall diameter (>1.5 times normal) and loss of parallelism. This disease is responsible for 1-4% mortality occurring on rupture in males older than 65 years. Due to its asymptomatic nature, proteomic techniques were used to search for diagnostic biomarkers that might allow surgical intervention under nonlife threatening conditions. METHODOLOGY/PRINCIPAL FINDINGS: Pooled human plasma samples of 17 AAA and 17 control patients were depleted of the most abundant proteins and compared using a data-independent shotgun proteomic strategy, Precursor Acquisition Independent From Ion Count (PAcIFIC), combined with spectral counting and isobaric tandem mass tags. Both quantitative methods collectively identified 80 proteins as statistically differentially abundant between AAA and control patients. Among differentially abundant proteins, a subgroup of 19 was selected according to Gene Ontology classification and implication in AAA for verification by Western blot (WB) in the same 34 individual plasma samples that comprised the pools. From the 19 proteins, 12 were detected by WB. Five of them were verified to be differentially up-regulated in individual plasma of AAA patients: adiponectin, extracellular superoxide dismutase, protein AMBP, kallistatin and carboxypeptidase B2. CONCLUSIONS/SIGNIFICANCE: Plasma depletion of high abundance proteins combined with quantitative PAcIFIC analysis offered an efficient and sensitive tool for the screening of new potential biomarkers of AAA. However, WB analysis to verify the 19 PAcIFIC identified proteins of interest proved inconclusive save for five proteins. We discuss these five in terms of their potential relevance as biological markers for use in AAA screening of population at risk

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century