Sargassum polyceratium (Phaeophyceae, Fucaceae) surface molecule activity towards fouling organisms and embryonic development of benthic species

International audienceCoral reefs have undergone profound ecological changes over recent decades. Areas formerly covered by scleractinian coral species are now often overgrown by macroalgae. In Martinique (West Indies), this phenomenon has lead to the colonisation of numerous coral reefs by algae, amongst which Sargassum is one of the most prominent. This study focuses on potential defence molecules produced by Sargassum polyceratium. The hexane dipping method was employed to extract surface molecules on fresh material, and their bioactivities were assessed against bacteria (marine and estuarine), and marine tropical invertebrates wan annelid (Pseudonereis sp.), a bivalve (Codakia orbicularis) and a sea urchin (Diadema antillarum)x. Extracts were active against all microorganisms tested (MICs150 or 300 mg ml-1), early stages of development in Pseudonereis sp. (MICs100 mg ml-1) and embryos of C. orbicularis and D. antillarum (MICs5 mg ml-1), suggesting the production of defence compounds by S. polyceratium

Diagnostic du Covid-19 en milieu ambulatoire [COVID-19 Diagnosis]

The need to curb the circulation of SARS-CoV-2 virus in the community and to diagnose those at risk of developing complications implies that an appropriate test should be chosen according to the epidemiological and clinical context. Rapid antigen tests, either nasopharyngeal or nasal, have the advantage of reflecting contagiousness better than PCR and giving an immediate result, reason why they are used as first-line for community diagnosis and screening. A rapid test allows immediate management of outpatients and does not falsely attribute the current acute episode to a previous SARS-CoV-2 infection. PCR, whether nasopharyngeal or buccosalivary, is useful for epidemiological surveillance, including that of new variants, as well as identification of severe COVID in the post-infectious phase

Prevalence of SARS-CoV-2 in Household Members and Other Close Contacts of COVID-19 Cases: A Serologic Study in Canton of Vaud, Switzerland.

Research on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission within households and other close settings using serological testing is scarce. We invited coronavirus disease 2019 (COVID-19) cases diagnosed between February 27 and April 1, 2020, in Canton of Vaud, Switzerland, to participate, along with household members and other close contacts. Anti-SARS-CoV-2 immunoglobulin G antibodies were measured using a Luminex immunoassay. We estimated factors associated with serological status using generalized estimating equations. Overall, 219 cases, 302 household members, and 69 other close contacts participated between May 4 and June 27, 2020. More than half of household members (57.2%; 95% CI, 49.7%-64.3%) had developed a serologic response to SARS-CoV-2, while 19.0% (95% CI, 10.0%-33.2%) of other close contacts were seropositive. After adjusting for individual and household characteristics, infection risk was higher in household members aged ≥65 years than in younger adults (adjusted odds ratio [aOR], 3.63; 95% CI, 1.05-12.60) and in those not strictly adhering to simple hygiene rules like hand washing (aOR, 1.80; 95% CI, 1.02-3.17). The risk was lower when more than 5 people outside home were met during semiconfinement, compared with none (aOR, 0.35; 95% CI, 0.16-0.74). Individual risk of household members to be seropositive was lower in large households (22% less per each additional person). During semiconfinement, household members of a COVID-19 case were at very high risk of getting infected, 3 times more than close contacts outside home. This highlights the need to provide clear messages on protective measures applicable at home. For elderly couples, who were especially at risk, providing external support for daily basic activities is essential

PKCα and PKCδ Regulate ADAM17-Mediated Ectodomain Shedding of Heparin Binding-EGF through Separate Pathways

Epidermal growth factor receptor (EGFR) signalling is initiated by the release of EGFR-ligands from membrane-anchored precursors, a process termed ectodomain shedding. This proteolytic event, mainly executed by A Disintegrin And Metalloproteases (ADAMs), is regulated by a number of signal transduction pathways, most notably those involving protein kinase C (PKC). However, the molecular mechanisms of PKC-dependent ectodomain shedding of EGFR-ligands, including the involvement of specific PKC isoforms and possible functional redundancy, are poorly understood. To address this issue, we employed a cell-based system of PMA-induced PKC activation coupled with shedding of heparin binding (HB)-EGF. In agreement with previous studies, we demonstrated that PMA triggers a rapid ADAM17-mediated release of HB-EGF. However, PMA-treatment also results in a protease-independent loss of cell surface HB-EGF. We identified PKCα as the key participant in the activation of ADAM17 and suggest that it acts in parallel with a pathway linking PKCδ and ERK activity. While PKCα specifically regulated PMA-induced shedding, PKCδ and ERK influenced both constitutive and inducible shedding by apparently affecting the level of HB-EGF on the cell surface. Together, these findings indicate the existence of multiple modes of regulation controlling EGFR-ligand availability and subsequent EGFR signal transduction

Données de santé : le nouvel or numérique, mais pour qui ? [Health data: the new digital gold, but for whom?]

Rapidly growing health-related data have the potential to improve health and healthcare, as well as to make health systems more efficient and focused on patients' needs. Their efficient and secure management represents major technological, organizational and societal challenges. Currently too compartmentalized and insufficiently accessible, these data are often in the hands of private providers and their collection does not necessarily guarantee data security and privacy protection. Professionals as well as some private for-profit companies are on the lookout for this new digital "gold". It is therefore urgent to define a democratic and legal framework for the governance, collection and use of health data in the highly decentralized and fragmented Swiss context

A digital health algorithm to guide antibiotic prescription in pediatric outpatient care: a cluster randomized controlled trial.

Excessive antibiotic use and antimicrobial resistance are major global public health threats. We developed ePOCT+, a digital clinical decision support algorithm in combination with C-reactive protein test, hemoglobin test, pulse oximeter and mentorship, to guide health-care providers in managing acutely sick children under 15 years old. To evaluate the impact of ePOCT+ compared to usual care, we conducted a cluster randomized controlled trial in Tanzanian primary care facilities. Over 11 months, 23,593 consultations were included from 20 ePOCT+ health facilities and 20,713 from 20 usual care facilities. The use of ePOCT+ in intervention facilities resulted in a reduction in the coprimary outcome of antibiotic prescription compared to usual care (23.2% versus 70.1%, adjusted difference -46.4%, 95% confidence interval (CI) -57.6 to -35.2). The coprimary outcome of day 7 clinical failure was noninferior in ePOCT+ facilities compared to usual care facilities (adjusted relative risk 0.97, 95% CI 0.85 to 1.10). There was no difference in the secondary safety outcomes of death and nonreferred secondary hospitalizations by day 7. Using ePOCT+ could help address the urgent problem of antimicrobial resistance by safely reducing antibiotic prescribing. Clinicaltrials.gov Identifier: NCT05144763

ePOCT+ and the medAL-; suite; : development of an electronic clinical decision support algorithm and digital platform for pediatric outpatients in low- and middle-income countries

Electronic clinical decision support algorithms (CDSAs) have been developed to address high childhood mortality and inappropriate antibiotic prescription by helping clinicians adhere to guidelines. Previously identified challenges of CDSAs include their limited scope, usability, and outdated clinical content. To address these challenges we developed ePOCT+, a CDSA for the care of pediatric outpatients in low- and middle-income settings, and the medical algorithm suite (medAL-suite), a software for the creation and execution of CDSAs. Following the principles of digital development, we aim to describe the process and lessons learnt from the development of ePOCT+ and the medAL-suite. In particular, this work outlines the systematic integrative development process in the design and implementation of these tools required to meet the needs of clinicians to improve uptake and quality of care. We considered the feasibility, acceptability and reliability of clinical signs and symptoms, as well as the diagnostic and prognostic performance of predictors. To assure clinical validity, and appropriateness for the country of implementation the algorithm underwent numerous reviews by clinical experts and health authorities from the implementing countries. The digitalization process involved the creation of medAL-creator, a digital platform which allows clinicians without IT programming skills to easily create the algorithms, and medAL-reader the mobile health (mHealth) application used by clinicians during the consultation. Extensive feasibility tests were done with feedback from end-users of multiple countries to improve the clinical algorithm and medAL-reader software. We hope that the development framework used for developing ePOCT+ will help support the development of other CDSAs, and that the open-source medAL-suite will enable others to easily and independently implement them. Further clinical validation studies are underway in Tanzania, Rwanda, Kenya, Senegal, and India

ePOCT+ and the medAL-suite: Development of an electronic clinical decision support algorithm and digital platform for pediatric outpatients in low- and middle-income countries.

Electronic clinical decision support algorithms (CDSAs) have been developed to address high childhood mortality and inappropriate antibiotic prescription by helping clinicians adhere to guidelines. Previously identified challenges of CDSAs include their limited scope, usability, and outdated clinical content. To address these challenges we developed ePOCT+, a CDSA for the care of pediatric outpatients in low- and middle-income settings, and the medical algorithm suite (medAL-suite), a software for the creation and execution of CDSAs. Following the principles of digital development, we aim to describe the process and lessons learnt from the development of ePOCT+ and the medAL-suite. In particular, this work outlines the systematic integrative development process in the design and implementation of these tools required to meet the needs of clinicians to improve uptake and quality of care. We considered the feasibility, acceptability and reliability of clinical signs and symptoms, as well as the diagnostic and prognostic performance of predictors. To assure clinical validity, and appropriateness for the country of implementation the algorithm underwent numerous reviews by clinical experts and health authorities from the implementing countries. The digitalization process involved the creation of medAL-creator, a digital platform which allows clinicians without IT programming skills to easily create the algorithms, and medAL-reader the mobile health (mHealth) application used by clinicians during the consultation. Extensive feasibility tests were done with feedback from end-users of multiple countries to improve the clinical algorithm and medAL-reader software. We hope that the development framework used for developing ePOCT+ will help support the development of other CDSAs, and that the open-source medAL-suite will enable others to easily and independently implement them. Further clinical validation studies are underway in Tanzania, Rwanda, Kenya, Senegal, and India

Antifouling compounds from the sub-arctic ascidian Synoicum pulmonaria: synoxazolidinones A and C, pulmonarins A and B, and synthetic analogues.

International audienceThe current study describes the antifouling properties of four members belonging to the recently discovered synoxazolidinone and pulmonarin families, isolated from the sub-Arctic sessile ascidian Synoicum pulmonaria collected off the Norwegian coast. Four simplified synthetic analogues were also prepared and included in the study. Several of the studied compounds displayed MIC values in the micro-nanomolar range against 16 relevant marine species involved in both the micro- and macrofouling process. Settlement studies on Balanus improvisus cyprids indicated a deterrent effect and a low toxicity for selected compounds. The two synoxazolidinones displayed broad activity and are shown to be among the most active natural antifouling bromotyrosine derivatives described. Synoxazolidinone C displayed selected antifouling properties comparable to the commercial antifouling product Sea-Nine-211. The pulmonarins prevented the growth of several bacterial strains at nanomolar concentrations but displayed a lower activity toward microalgae and no effect on barnacles. The linear and cyclic synthetic peptidic mimics also displayed potent antifouling activities mainly directed against bacterial adhesion and growth

Molecular characterization and expression analysis of the putative interleukin 6 receptor (IL-6Rα and glycoprotein-130) in rainbow trout (Oncorhynchus mykiss): salmonid IL-6Rα possesses a polymorphic N-terminal Ig-domain with variable numbers of two repeats

16 páginas, 6 figuras, 3 tablas.-- The final publication is available at www.springerlink.comInterleukin (IL)-6, the founding member of IL-6 family cytokines, plays non-redundant roles in hematopoiesis and acute phase responses. IL-6 signals via a specific private IL-6Rα and a common beta chain gp130. In this study, we sequence analysed both IL-6Rα and gp130 in rainbow trout. The trout gp130 cDNA encodes 906 aa and is similar in size, extracellular domain structure (D1-6) and presence of intracellular motifs important for signal transduction to tetrapod gp130. The trout IL-6Rα cDNA encodes for 834 aa and is larger compared to tetrapod IL-6Rαs, as are other fish IL-6Rα molecules due to a large D1 domain. However, the cytokine binding domain is well conserved across vertebrates, with four conserved cysteine residues in the N-terminal FNIII domain and a WSXWS motif in the C-terminal FNIII domain. Furthermore, phylogenetic tree analysis confirmed that the reported fish IL-6Rα and gp130 molecules are orthologues to their tetrapod counterparts. The extra-large D1 domain of the salmonid IL-6Rα molecules results from the insertions of two repetitive sequences of [TS]-[TF]-VSTTT-[ND]-TTSNG and TTVS-[AT]-IKD-[DG]-S-[KD]-N-[GR], respectively. Furthermore the numbers of repetitions of the two motifs were variable in different individuals and cell lines, and even in the same fish allelic polymorphism exists. Trout IL-6Rα was expressed at higher levels than gp130 in a number of tissues examined and the expression of both IL-6Rα and gp130 could be modulated by LPS and Poly I:C in four trout cell lines studied. The expression patterns of the receptors suggest that high level expression of IL-6Rα is critical for IL-6 responsiveness.The work was supported by a European Community project IMAQUANIM (FOOD-CT-2005-007103). M.M.C. thanks the Consejo Superior de Investigaciones Científicas (CSIC, Spain) and the Xunta de Galicia for her “Ángeles Alvariño” postdoctoral contract. M.M.M. thanks the FCT (Foundation for Science and Technology, Portugal) and POPH/FSE for her PhD studentship (Grant no. SFRH/ BD/ 38236/ 2007).Peer reviewe