Proposal of a quantitative PCR-based protocol for an optimal Pseudomonas aeruginosa detection in patients with cystic fibrosis

BACKGROUND: The lung of patients with cystic fibrosis (CF) is particularly sensitive to Pseudomonas aeruginosa. This bacterium plays an important role in the poor outcome of CF patients. During the disease progress, first acquisition of P. aeruginosa is the key-step in the management of CF patients. Quantitative PCR (qPCR) offers an opportunity to detect earlier the first acquisition of P. aeruginosa by CF patients. Given the lack of a validated protocol, our goal was to find an optimal molecular protocol for detection of P. aeruginosa in CF patients. METHODS: We compared two formerly described qPCR formats in early detection of P. aeruginosa in CF sputum samples: a qPCR targeting oprL gene, and a multiplex PCR targeting gyrB and ecfX genes. RESULTS: Tested in vitro on a large panel of P. aeruginosa isolates and others gram-negative bacilli, oprL qPCR exhibited a better sensitivity (threshold of 10 CFU/mL versus 730 CFU/mL), whereas the gyrB/ecfX qPCR exhibited a better specificity (90% versus 73%). These results were validated ex vivo on 46 CF sputum samples positive for P. aeruginosa in culture. Ex vivo assays revealed that qPCR detected 100 times more bacterial cells than culture-based method did. CONCLUSION: Based on these results, we proposed a reference molecular protocol combining the two qPCRs, which offers a sensitivity of 100% with a threshold of 10 CFU/mL and a specificity of 100%. This combined qPCR-based protocol can be adapted and used for other future prospective studies

HALESIS-Sat : Physical And Technical Feasibility To Observe Infrared Vibrational Signatures Of TLEs From Space.

International audienceImpact of Transient luminous phenomena (TLEs) on the local atmospheric composition, the vibrational chemistry they induce, and the associated energy deposition remain open questions. A number of studies, validated by ground, airborne and space observation campaigns, attribute the radiation of the sprites to the excitation of the electronic levels of N2 and N2+. However, the radiation due to the excited levels of CO2 molecules, envisioned by various authors and which would persist much longer after the advent of the sprite has never been measured to date. The thesis work of Frédéric Romand (Sorbonne Université) demonstrated that the infrared signature of CO2 could be observed either from a stratospheric balloon or from space. This open the way to observe influence of sprites on CO2 by spectroscopy. Since this influence can itself be a function of space, we would also like to spatially resolve the signature, which directs the choice of instrumentation towards a spectro-imager. As the observed phenomenon evolves rapidly, it is necessary to have a "snapshot" acquisition, that is to say that the hyperspectral cube (2 dimensions for space, one spectral dimension) can be taken instantaneously. Most spectro-imagers are scanning and therefore not suitable for the needs of the experiment. However, ONERA is currently developing a new type of spectro-imager called ImSpoc that would meet these needs. The sprite observation can be done from two angles: aiming at the horizontal limb, or aiming, vertically downwards. We will discuss a satellite approach and the main advantages (longer mission, global coverage), and we will present the feasibility of such an experiment, on two major aspects: Physical feasibility: is the phenomenon observable from space for the proposed instrumentation? (Frequency of events, signal-to-noise ratio, sensitivity of measuring devices, etc.) Technical feasibility: can a satellite fulfill this mission? (Energy consumption, data transmission, etc.

HALESIS-Sat : Physical And Technical Feasibility To Observe Infrared Vibrational Signatures Of TLEs From Space.

International audienceImpact of Transient luminous phenomena (TLEs) on the local atmospheric composition, the vibrational chemistry they induce, and the associated energy deposition remain open questions. A number of studies, validated by ground, airborne and space observation campaigns, attribute the radiation of the sprites to the excitation of the electronic levels of N2 and N2+. However, the radiation due to the excited levels of CO2 molecules, envisioned by various authors and which would persist much longer after the advent of the sprite has never been measured to date. The thesis work of Frédéric Romand (Sorbonne Université) demonstrated that the infrared signature of CO2 could be observed either from a stratospheric balloon or from space. This open the way to observe influence of sprites on CO2 by spectroscopy. Since this influence can itself be a function of space, we would also like to spatially resolve the signature, which directs the choice of instrumentation towards a spectro-imager. As the observed phenomenon evolves rapidly, it is necessary to have a "snapshot" acquisition, that is to say that the hyperspectral cube (2 dimensions for space, one spectral dimension) can be taken instantaneously. Most spectro-imagers are scanning and therefore not suitable for the needs of the experiment. However, ONERA is currently developing a new type of spectro-imager called ImSpoc that would meet these needs. The sprite observation can be done from two angles: aiming at the horizontal limb, or aiming, vertically downwards. We will discuss a satellite approach and the main advantages (longer mission, global coverage), and we will present the feasibility of such an experiment, on two major aspects: Physical feasibility: is the phenomenon observable from space for the proposed instrumentation? (Frequency of events, signal-to-noise ratio, sensitivity of measuring devices, etc.) Technical feasibility: can a satellite fulfill this mission? (Energy consumption, data transmission, etc.

Naturally occurring substitutions conferring resistance to hepatitis C virus polymerase inhibitors in treatment-naive patients infected with genotypes 1-5

International audienceBACKGROUND: The hepatitis C virus (HCV) RNA-dependent RNA polymerase, NS5B, is essential for virus RNA replication. It is thus an attractive therapeutic target. Several compound nucleoside analogues, non-nucleoside inhibitors and cyclosporine analogues are being developed to inhibit NS5B activity. However, nucleotide changes in the NS5B gene can confer resistance to them.METHODS: We investigated the prevalence of known substitutions conferring resistance in HCV polymerase in 124 treatment-naive French patients infected with HCV genotypes 1, 2, 3, 4 or 5 by sequencing the NS5B gene. RESULTS: None of the 124 HCV NS5B sequences analysed contained substitutions conferring resistance to nucleoside analogues; however, NS5B polymerases containing substitutions conferring resistance to non-nucleoside inhibitors were frequent within genotype 1 strains (17%) and very common in non-genotype 1 strains. Similarly, substitutions conferring resistance to cyclosporine analogues were more prevalent within the various genotypes. CONCLUSIONS: Naturally occurring substitutions conferring resistance to NS5B inhibitors are common in treatment-naive patients infected with HCV genotype 1, 2, 3, 4 or 5. Their influence on treatment outcome should be assessed.</p

NS3 protease polymorphism and resistance profile to protease inhibitors in French patients infected with Hepatitis C Virus (HCV) genotypes 1 to 5

Date du colloque&nbsp;: 09/2009</p

NS3 protease polymorphism and resistance profile to protease inhibitors in French patients infected with Hepatitis C Virus (HCV) genotypes 1 to 5

Date du colloque&nbsp;: 09/2009</p

NS3 protease polymorphism and natural resistance to protease inhibitors in French patients infected with HCV genotypes 1–5

International audienc

Expertise en vue de la fixation de valeurs limites d’exposition à des agents chimiques en milieu professionnel. Évaluation des indicateurs biologiques d’exposition en vue de la recommandation de valeurs biologiques de référence pour le 2-méthoxy-1-propanol (n° CAS 1589-47-5) et l’acétate de 2-méthoxypropyle (n° CAS 70657-70-4).: Avis de l’AnsesRapport d’expertise collective

Anses. (2022). Expertise en vue de la fixation de valeurs limites d’exposition à des agents chimiques en milieu professionnel. Évaluation des indicateurs biologiques d’exposition en vue de la recommandation de valeurs biologiques de référence pour le 2-méthoxy-1-propanol (n° CAS 1589-47-5) et l’acétate de 2-méthoxypropyle (n° CAS 70657-70-4). (saisine 2012-SA-0073). Maisons-Alfort : Anses, 56 p.On 3 February 2012, Anses received a formal request from the French Directorate General for Labour (DGT) to conduct the expert appraisal work required for recommending biological monitoring in the workplace for 2-methoxy-1-propanol and its acetate, 2-methoxypropyl acetate. There are two isomers of propylene glycol monomethyl ether (PGME): 1-methoxy-2-propanol (2PG1ME or PGMEα, CAS No. 107-98-2) and 2-methoxy-1-propanol (1PG2ME or PGMEβ, CAS No. 1589-47-5); the respective acetates are 1-methoxy-2-propanol acetate (2PG1MEA or PGMAα, CAS No. 108-65-6) and 2-methoxypropyl acetate (1PG2MEA or PGMAβ, CAS No. 70657-70-4). In this report, 1-methoxy-2-propanol and its acetate will be referred to respectively as PGMEα and PGMAα while 2-methoxy-1-propanol and its acetate will be referred to as PGMEβ and PGMAβ.Since PGMEβ and its acetate are classified as reprotoxic (Category 1B) under the CLP Regulation, a concentration of at least 0.3% PGMEβ and/or PGMAβ in the commercial form of PGME results in a 1B reprotoxic classification. France does not currently have any occupational exposure limits for PGMEβ and its acetate. However, since 2007, PGMEα, as well as its acetate, have binding limit values, i.e. an 8h-OEL of 50 ppm and a 15min-STEL of 100 ppm.In an opinion published in 2008 (AFSSET 2008), AFSSET recommended, to “limit the risk of occupational exposure, strengthening biological surveillance in the workplace by developing markers for 2-methoxypropionic acid (2-MPA), the main metabolite of 1PG2ME and its acetate, and by systematically measuring urinary levels, instead of atmospheric levels, to be able to assess the overall exposure of workers”. The DGT thus asked ANSES to assess the relevance of recommending monitoring one or more biomarkers and the elaboration of biological limit values for the selected biomarker(s).L’Anses a été saisie le 3 février 2012 par la direction générale du travail (DGT) afin de mener les travaux d’expertise nécessaires à la fixation de valeurs limites d’exposition professionnelle (VLEP) pour une dizaine de substances dont le 2-méthoxy-1-propanol et son acétate, l’acétate de 2-méthoxypropyle. Il existe deux isomères du propylène glycol monométhyléther (PGME) : le 1-méthoxy-2-propanol (2PG1ME ou PGMEα, CAS no 107-98-2) et le 2-méthoxy-1-propanol (1PG2ME ou PGMEβ, CAS no 1589-47-5), les acétates respectifs étant l’acétate de 1-méthoxy-2-propanol (2PG1MEA ou PGMAα, CAS no 108-65-6) et l’acétate de 2-méthoxypropyle (1PG2MEA ou PGMAβ, CAS no 70657-70-4). Le 1-méthoxy-2-propanol et son acétate seront désignés respectivement par les abréviations PGMEα et PGMAα, tandis que le 2-méthoxy-1-propanol et son acétate seront désignés respectivement par les abréviations PGMEβ et PGMAβ.Le PGMEβ et son acétate étant classés reprotoxiques (catégorie 1B) par le règlement CLP, la présence de PGMEβ et/ou PGMAβ dans la forme commerciale du PGME entraîne une classification reprotoxique 1B lorsque sa concentration est au moins égale 0,3 %. La France ne dispose à ce jour d’aucune valeur limite d’exposition professionnelle pour le PGMEβ et son acétate. Cependant, le PGMEα et son acétate disposent depuis 2007 de valeurs limites contraignantes, à savoir une VLEP-8h de 50 ppm et une VLCT-15 min de 100 ppm. Dans un avis publié en 2008 (AFSSET 20084 ), l’AFSSET a recommandé, pour « limiter le risque d’exposition en milieu professionnel, de renforcer la surveillance professionnelle biologique par le développement d’indicateurs pour l’acide 2-méthoxypropionique (2-MPA), métabolite principal du 1PG2ME et de son acétate, et par sa mesure urinaire systématique, à la place de la mesure atmosphérique, pour pouvoir évaluer les expositions globales des travailleurs ». Aussi la DGT a demandé à l’Anses d’évaluer le 2-méthoxy-1-propanol et son acétate afin d’établir la pertinence de recommander le suivi d’un ou plusieurs indicateurs biologiques et l’établissement de valeurs limites biologiques pour l’(les) indicateur(s) retenu(s)

Automated Categorization of Parkinsonian Syndromes Using Magnetic Resonance Imaging in a Clinical Setting

International audienceBackgroundMachine learning algorithms using magnetic resonance imaging (MRI) data can accurately discriminate parkinsonian syndromes. Validation in patients recruited in routine clinical practice is missing.ObjectiveThe aim of this study was to assess the accuracy of a machine learning algorithm trained on a research cohort and tested on an independent clinical replication cohort for the categorization of parkinsonian syndromes.MethodsThree hundred twenty‐two subjects, including 94 healthy control subjects, 119 patients with Parkinson's disease (PD), 51 patients with progressive supranuclear palsy (PSP) with Richardson's syndrome, 35 with multiple system atrophy (MSA) of the parkinsonian variant (MSA‐P), and 23 with MSA of the cerebellar variant (MSA‐C), were recruited. They were divided into a training cohort (n = 179) scanned in a research environment and a replication cohort (n = 143) examined in clinical practice on different MRI systems. Volumes and diffusion tensor imaging (DTI) metrics in 13 brain regions were used as input for a supervised machine learning algorithm. To harmonize data across scanners and reduce scanner‐dependent effects, we tested two types of normalizations using patient data or healthy control data.ResultsIn the replication cohort, high accuracies were achieved using volumetry in the classification of PD–PSP, PD–MSA‐C, PSP–MSA‐C, and PD‐atypical parkinsonism (balanced accuracies: 0.840–0.983, area under the receiver operating characteristic curves: 0.907–0.995). Performances were lower for the classification of PD–MSA‐P, MSA‐C–MSA‐P (balanced accuracies: 0.765–0.784, area under the receiver operating characteristic curve: 0.839–0.871) and PD–PSP–MSA (balanced accuracies: 0.773). Performance using DTI was improved when normalizing by controls, but remained lower than that using volumetry alone or combined with DTI.ConclusionsA machine learning approach based on volumetry enabled accurate classification of subjects with early‐stage parkinsonism, examined on different MRI systems, as part of their clinical assessment