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1.
Infect Dis Now ; 54(2): 104863, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38340891

ABSTRACT

OBJECTIVES: To evaluate current organization of infection prevention for immunocompromised patients (ICP) at a countrywide level. METHODS: Nationwide cross-sectional multicenter study based on an online survey disseminated in 2022 to physicians invested with preventive healthcare missions. RESULTS: A total of 341 physicians (96% graduates, 32% infectious disease specialists), participated in the survey, with a median age of 40 [35-51] years. On-site access to infection prevention consultations for ICP was reported by 30%, dedicated pre-travel consultations for ICPs by 29%, consultations for infection prevention in solid organ transplant candidates by 16% and return-to-work consultations for ICPs by 6%. Most participants (73%) were aware of nationwide vaccination guidelines for ICP, while 50% felt comfortable using them. Tools for infection prevention advice and ICP vaccination had been developed by 10%, while 89% would have appreciated access to tools developed by others. CONCLUSIONS: Infection prevention for ICPs remains neglected. Guidelines covering all fields of prevention for ICPs would be more than welcome.


Subject(s)
Health Facilities , Immunocompromised Host , Humans , Adult , Middle Aged , Cross-Sectional Studies , France , Vaccination
2.
Eur J Med Genet ; 68: 104919, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38355093

ABSTRACT

Hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber disease, is a dominant inherited vascular disorder. The clinical diagnosis is based on the Curaçao criteria and pathogenic variants in the ENG and ACVRL1 genes are responsible for most cases of HHT. Four families with a negative targeted gene panel and selected by a multidisciplinary team were selected and whole-genome sequencing was performed according to the recommendations of the French National Plan for Genomic Medicine. Structural variations were confirmed by standard molecular cytogenetic analysis (FISH). In two families with a definite diagnosis of HHT, we identified two different paracentric inversions of chromosome 9, both disrupting the ENG gene. These inversions are considered as pathogenic and causative for the HHT phenotype of the patients. This is the first time structural variations are reported to cause HHT. As such balanced events are often missed by exon-based sequencing (panel, exome), structural variations may be an under-recognized cause of HHT. Genome sequencing for the detection of these events could be suggested for patients with a definite diagnosis of HHT and in whom no causative pathogenic variant was identified.


Subject(s)
Telangiectasia, Hereditary Hemorrhagic , Humans , Telangiectasia, Hereditary Hemorrhagic/diagnosis , Telangiectasia, Hereditary Hemorrhagic/genetics , Telangiectasia, Hereditary Hemorrhagic/pathology , Mutation , Endoglin/genetics , Base Sequence , Chromosomes, Human, Pair 9/genetics , Activin Receptors, Type II/genetics
3.
Pediatr Res ; 95(4): 865-866, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38297155

Subject(s)
Career Choice
4.
Pediatr Res ; 2023 Dec 08.
Article in English | MEDLINE | ID: mdl-38066248

ABSTRACT

BACKGROUND: Lung inflammation and impaired alveolarization precede bronchopulmonary dysplasia (BPD). Glucocorticoids are anti-inflammatory and reduce ventilator requirements in preterm infants. However, high-dose glucocorticoids inhibit alveolarization. The effect of glucocorticoids on lung function and structure in preterm newborns exposed to antenatal inflammation is unknown. We hypothesise that postnatal low-dose dexamethasone reduces ventilator requirements, prevents inflammation and BPD-like lung pathology, following antenatal inflammation. METHODS: Pregnant ewes received intra-amniotic LPS (E.coli, 4 mg/mL) or saline at 126 days gestation; preterm lambs were delivered 48 h later. Lambs were randomised to receive either tapered intravenous dexamethasone (LPS/Dex, n = 9) or saline (LPS/Sal, n = 10; Sal/Sal, n = 9) commencing <3 h after birth. Respiratory support was gradually de-escalated, using a standardised protocol aimed at weaning from ventilation towards unassisted respiration. Tissues were collected at day 7. RESULTS: Lung morphology and mRNA levels for inflammatory mediators were measured. Respiratory support requirements were not different between groups. Histological analyses revealed higher tissue content and unchanged alveolarization in LPS/Sal compared to other groups. LPS/Dex lambs exhibited decreased markers of pulmonary inflammation compared to LPS/Sal. CONCLUSION: Tapered low-dose dexamethasone reduces the impact of antenatal LPS on ventilation requirements throughout the first week of life and reduces inflammation and pathological thickening of the preterm lung IMPACT: We are the first to investigate the combination of antenatal inflammation and postnatal dexamethasone therapy in a pragmatic study design, akin to contemporary neonatal care. We show that antenatal inflammation with postnatal dexamethasone therapy does not reduce ventilator requirements, but has beneficial maturational impacts on the lungs of preterm lambs at 7 days of life. Appropriate tapered postnatal dexamethasone dosing should be explored for extuabtion of oxygen-dependant neonates.

5.
Arch Pediatr ; 30(6): 366-371, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37188563

ABSTRACT

BACKGROUND: Infantile hemangiomas (IHs) can be part of PHACE (posterior fossa anomalies, hemangioma, arterial anomalies, cardiac anomalies, eye anomalies) syndrome when they are segmental, extensive, and located on the face or neck. The initial assessment is codified and well known, but there are no recommendations for the follow-up of these patients. The aim of this study was to assess the long-term prevalence of different associated abnormalities. METHODS: Patients with a history of large segmental IHs of the face or neck. diagnosed between 2011 and 2016 were included in the study. Each patient underwent an ophthalmological, dental, ENT (ear, nose, and throat), dermatological, neuro-pediatric, and radiological assessment at inclusion. Eight patients including five with PHACE syndrome were prospectively evaluated. RESULTS: After a mean follow-up of 8.5 years, three patients presented with an angiomatous aspect of the oral mucosa, two with hearing loss, and two with otoscopic abnormalities. No patients developed ophthalmological abnormalities. The neurological examination was altered in three cases. Brain magnetic resonance imaging follow-up was unchanged in three out four patients and revealed atrophy of the cerebellar vermis in 1 patient. Neurodevelopmental disorders were found in five of the patients and learning difficulties were observed in five patients. The S1 location appears to be associated with a higher risk of neurodevelopmental disorders and cerebellar malformations, while the S3 location was associated with more progressive complications, including neurovascular, cardiovascular, and ENT abnormalities. CONCLUSION: Our study reported late complications in patients with a large segmental IH of the face or neck, whether associated with PHACE syndrome or not, and we proposed an algorithm to optimize the long-term follow-up.


Subject(s)
Aortic Coarctation , Eye Abnormalities , Hemangioma , Neurocutaneous Syndromes , Humans , Child , Infant , Prospective Studies , Follow-Up Studies , Eye Abnormalities/diagnosis , Eye Abnormalities/complications , Eye Abnormalities/pathology , Aortic Coarctation/complications , Aortic Coarctation/diagnosis , Aortic Coarctation/pathology , Neurocutaneous Syndromes/diagnosis , Neurocutaneous Syndromes/complications , Neurocutaneous Syndromes/pathology , Hemangioma/diagnosis , Hemangioma/pathology , Syndrome
6.
Infect Dis Now ; 52(8): 447-452, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36108975

ABSTRACT

OBJECTIVES: To estimate the SARS-CoV-2 IgG seroprevalence rate in healthcare workers (HCWs) from Western France after the first 2020 wave, its determinants and the kinetics of total SARS-CoV-2 antibodies. PATIENTS AND METHODS: Overall, 9,453 HCWs responded to a self-questionnaire and underwent a lateral flow immunoassay to assess SARS-CoV-2 IgG presence. For 72 HCWs who tested positive, total anti-nucleocapsid antibodies were assessed at day 0, 30, and 90. RESULTS: SARS-CoV-2 IgG seroprevalence rate was 1.06 % [0.86 %-1.27 %]. Factors associated with IgG presence were gender, performing upper respiratory tract samples, contact with HCWs or household members diagnosed with COVID-19. Total antibodies decreased between day 0 and day 90, with anosmia or ageusia, and were higher in HCWs older than 50 years. CONCLUSION: We reported a low prevalence rate of IgG and identified several risk factors associated with its presence and persistence of total antibodies. Additional studies are needed to confirm these observations.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Seroepidemiologic Studies , COVID-19/epidemiology , Antibodies, Viral , Health Personnel , Immunoglobulin G , Hospitals
7.
J Appl Physiol (1985) ; 133(4): 959-969, 2022 10 01.
Article in English | MEDLINE | ID: mdl-36074925

ABSTRACT

Abnormalities of the airway smooth muscle (ASM) layer in asthma may develop before birth. We hypothesize that antenatal inflammation causes physiological abnormalities of the ASM that predisposes asthma. This study determined the short-term effects of antenatal inflammation on the developing ASM. Fourteen pregnant ewes were randomly assigned to one of three groups. Fetal lambs were exposed to intra-amniotic injections of lipopolysaccharide (LPS, n = 4) or saline (controls; n = 5) at 127 days' gestational age (GA). Preterm lambs were surgically delivered at 129 days' GA and received intensive care for 7 days before euthanasia. Naïve fetal controls (n = 5) were delivered and euthanized at 136 days' GA. ASM force to acetylcholine was measured in bronchial rings and normalized to ring length (tension) and ASM cross-sectional area (stress). Airway narrowing (% volume) to acetylcholine was assessed in bronchial segments. Fetal controls were structurally and functionally similar to saline-exposed lambs. Compared with saline, LPS-exposed lambs had increased macrophages in lung tissue (P = 0.0002) and interleukin-8 in alveolar wash (P = 0.003). LPS exposure increased ASM thickness (P = 0.005), airway narrowing (P = 0.003), ASM tension (P = 0.0002), and contractile stress (P < 0.0001). Notably, LPS-exposed lambs were more dependent on mechanical ventilation, and both LPS (P < 0.001) and ventilation (P = 0.012) were independent factors in increasing ASM stress. Only LPS independently increased ASM thickness (P = 0.045). Results indicate that antenatal exposure to LPS and subsequent mechanical ventilation promotes intrinsic changes to the ASM that enhances bronchoconstriction. If persistent into postnatal life, these developmental abnormalities may contribute to the known association between chorioamnionitis and asthma.NEW & NOTEWORTHY Abnormalities of the airway smooth muscle (ASM) layer in asthma may develop before birth. Using an ovine model of antenatal inflammation, we demonstrate thickening and increased contraction of the premature ASM layer. If such physiological abnormalities persist throughout postnatal life, this represents a predisposition to an asthma diagnosis.


Subject(s)
Asthma , Pregnancy Complications , Premature Birth , Acetylcholine/pharmacology , Animals , Female , Inflammation , Interleukin-8 , Lipopolysaccharides/pharmacology , Muscle Contraction , Muscle, Smooth , Pregnancy , Premature Birth/veterinary , Sheep
8.
Sci Rep ; 12(1): 14662, 2022 08 29.
Article in English | MEDLINE | ID: mdl-36038621

ABSTRACT

Ancient charcoal fragments, produced by the use of wood as fuel in archaeological contexts or during natural or anthropic forest fires, persist in soil and sediments over centuries to millennia. They thus offer a unique window to reconstruct past climate, especially palaeo-precipitation regimes thanks to their stable carbon isotope composition. However, the initial δ13C of wood is slightly modified as a function of the carbonisation temperature. Carbonisation-induced 13C fractionation is classically investigated through a transfer function between experimental carbonisation temperatures and the carbon content. This approach assumes that the carbon content is conservative through time in ancient charcoals and neglects the potential impact of post-depositional oxidation occurring in soils and sediments. In the present study, we first show that post-depositional oxidation can lead to a large underestimation of past carbonisation temperatures, thereby minimising the estimation of carbonisation-induced 13C fractionations and possibly biasing δ13C-based climate reconstructions. Secondly, by combining carbon content, Fourier-transform infrared and Raman spectroscopy, we propose a new framework to assess the carbonisation temperatures registered in ancient charcoals. This new framework paves the way to reassessing δ13C-based climate reconstruction.


Subject(s)
Charcoal , Soil , Carbon , Carbon Isotopes/analysis , Charcoal/chemistry , Climate , Temperature
9.
Front Physiol ; 13: 904144, 2022.
Article in English | MEDLINE | ID: mdl-35860659

ABSTRACT

Initiation of respiratory support in the delivery room increases the risk and severity of brain injury in preterm neonates through two major pathways: an inflammatory pathway and a haemodynamic pathway. The relative contribution of each pathway on preterm brain injury is not known. We aimed to assess the role of the inflammatory and haemodynamic pathway on ventilation-induced brain injury (VIBI) in the preterm lamb. Fetal lambs (125 ± 1 day gestation) were exteriorised, instrumented and ventilated with a high tidal-volume (VT) injurious strategy for 15 min either with placental circulation intact to induce the inflammatory pathway only (INJINF; n = 7) or umbilical cord occluded to induce both the inflammatory and haemodynamic pathways (INJINF+HAE; n = 7). Sham controls were exteriorised but not ventilated (SHAM; n = 5) while unoperated controls (UNOP; n = 7) did not undergo fetal instrumentation. Fetuses were returned in utero following intervention and the ewe allowed to recover. Arterial blood gases and plasma were sampled periodically. Twenty-four hours following intervention, lambs were delivered and maintained on non-injurious ventilation for ∼40 min then brains were collected post-mortem for immunohistochemistry and RT-qPCR to assess inflammation, vascular pathology and cell death within white matter regions. Compared to INJINF lambs, INJINF+HAE lambs achieved a consistently higher VT during injurious ventilation and carotid blood flow was significantly lower than baseline by the end of ventilation. Throughout the 24 h recovery period, systemic arterial IL-6 levels of INJINF+HAE lambs were significantly higher than SHAM while there was no difference between INJINF and SHAM animals. At 24 h, mRNA expression levels of pro-inflammatory cytokines, tight junction proteins, markers of cell death, and histological injury indices of gliosis, blood vessel protein extravasation, oligodendrocyte injury and cell death were not different between groups. Injurious ventilation, irrespective of strategy, did not increase brain inflammation or injury 24 h later when compared to control animals. However, the haemodynamic pathway did influence carotid blood flow adaptations during injurious ventilation and increased systemic arterial IL-6 that may underlie long-term pathology. Future studies are required to further characterise the pathways and their long-term effects on VIBI.

10.
Infect Dis Now ; 52(4): 223-226, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35513223

ABSTRACT

OBJECTIVE: To characterize the willingness to get the third COVID-19 vaccine dose among health care workers (HCWs). METHODS: A cross-sectional study using a self-administered questionnaire proposed on a voluntary basis to all HCWs of a French teaching hospital in October and November 2021. RESULTS: Of 1,655 HCWs who completed the questionnaire, 64.2% were willing to receive the third dose, 20.1% were hesitant, and 15.7% were reluctant. On multivariate analysis, older age (P<0.0001), medical and executive staff, willingness to receive the flu vaccine (OR=5.72 [4.24-7.64]), previous vaccine scheme with ChAdOx1 nCoV-19 (AstraZeneca) (OR=2.13 [1.58-2.87]), and history of COVID-19 with a complete COVID-19 vaccine scheme (OR=2.77 [1.04-7.41]) were independent predictors of HCWs' willingness to get the third dose. CONCLUSIONS: One third of HCWs were hesitant or opposed to a third COVID-19 vaccine dose. Better knowledge of determinants of the willingness to get this third dose may improve communication and vaccine strategy.


Subject(s)
COVID-19 , Influenza, Human , Attitude of Health Personnel , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , ChAdOx1 nCoV-19 , Cross-Sectional Studies , Health Personnel , Humans , Influenza, Human/prevention & control , Patient Acceptance of Health Care
11.
Front Pharmacol ; 13: 870156, 2022.
Article in English | MEDLINE | ID: mdl-35401240

ABSTRACT

There is an urgent need to develop effective therapeutic strategies including immunomodulators to combat influenza A virus (IAV) infection. Influenza A viruses increase ROS production, which suppress anti-viral responses and contribute to pathological inflammation and morbidity. Two major cellular sites of ROS production are endosomes via the NOX2-oxidase enzyme and the electron transport chain in mitochondria. Here we examined the effect of administration of Cgp91ds-TAT, an endosome-targeted NOX2 oxidase inhibitor, in combination with mitoTEMPO, a mitochondrial ROS scavenger and compared it to monotherapy treatment during an established IAV infection. Mice were infected with IAV (Hkx31 strain; 104PFU/mouse) and 24 h post infection were treated with Cgp91ds-TAT (0.2 mg/kg), mitoTEMPO (100 µg) or with a combination of these inhibitors [Cgp91ds-TAT (0.2 mg/kg)/mitoTEMPO (100 µg)] intranasally every day for up to 2 days post infection (pi). Mice were euthanized on Days 3 or 6 post infection for analyses of disease severity. A combination of Cgp91ds-TAT and mitoTEMPO treatment was more effective than the ROS inhibitors alone at reducing airway and neutrophilic inflammation, bodyweight loss, lung oedema and improved the lung pathology with a reduction in alveolitis following IAV infection. Dual ROS inhibition also caused a significant elevation in Type I IFN expression at the early phase of infection (day 3 pi), however, this response was suppressed at the later phase of infection (day 6 pi). Furthermore, combined treatment with Cgp91ds-TAT and mitoTEMPO resulted in an increase in IAV-specific CD8+ T cells in the lungs. In conclusion, this study demonstrates that the reduction of ROS production in two major subcellular sites, i.e. endosomes and mitochondria, by intranasal delivery of a combination of Cgp91ds-TAT and mitoTEMPO, suppresses the severity of influenza infection and highlights a novel immunomodulatory approach for IAV disease management.

12.
Inorg Chem ; 61(12): 5048-5059, 2022 Mar 28.
Article in English | MEDLINE | ID: mdl-35286077

ABSTRACT

In an effort to develop precursors for the production of lanthanide silicate (LnSiOx) materials, the reactions of [Ln(NR2)3] (R = SiMe3) with three equivalents of tris(trimethylsilyl)silanol (H-OSi(SiMe3)3) or H-SST) in tetrahydrofuran (THF) were undertaken. The products were crystallographically characterized as [Ln(SST)3(THF)2] (where Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu). In general, these compounds are similar to the previously reported [Gd(SST)3(THF)2] complex, where each metal center of the monomeric species is found to adopt a trigonal bipyramidal (TBP; τ = av 0.95) geometry; however, the crystallographic structure solutions for these crystals invoke a much larger unit cell that reveals the complex disorder of the axial THF ligands. Using incompletely washed H-SST, the tetrahedrally (T-4) bound [Ln(SST)3(NEt3)] (Ln-NEt3 = Pr-NEt3, Ho-NEt3; NEt3 = triethylamine) compounds were isolated from the same reaction run in toluene. Rational syntheses of amine derivatives were realized by performing the same reaction with pure H-SST in toluene containing the appropriate amine and [Ln(NR2)3] with the final products identified as [Tm(SST)3(NEt3)] (Tm-NEt3) or [Tm(SST)3(NHPr2i)] (NHPr2i = di-iso-propylamine; Tm-NHPr2i). The products isolated from reactions undertaken in pyridine (py) were identified as [Ln(SST)3(py)2] (Ln-py = Ce-py, Eu-py, and Tm-py). The Ln-py structures exhibit the larger unit cell noted for the THF derivatives with each Ln adopting a TBP (τ = av 0.98) metal center possessing equatorial SST and axial py ligands. The same reaction run in toluene led to the isolation of [(η6-tol)Tm(SST)3] (Tm-tol). Multinuclear NMR (1H and 29Si) data support the retention of the solid-state structures of all of these compounds in solution. Photoluminescent measurements of Tb, Sm, Dy, and Eu were found to display emission and lifetime profiles in the visible range due to f-f transitions, consistent with trivalent lanthanide metal centers.

13.
Proc Natl Acad Sci U S A ; 117(40): 24964-24973, 2020 10 06.
Article in English | MEDLINE | ID: mdl-32958663

ABSTRACT

Influenza A virus (IAV) infection during pregnancy causes severe maternal and perinatal complications, despite a lack of vertical transmission of IAV across the placenta. Here, we demonstrate a significant alteration in the maternal vascular landscape that underpins the maternal and downstream fetal pathology to IAV infection in mice. In IAV infection of nonpregnant mice, the local lung inflammatory response was contained to the lungs and was self-resolving, whereas in pregnant mice, virus dissemination to major maternal blood vessels, including the aorta, resulted in a peripheral "vascular storm," with elevated proinflammatory and antiviral mediators and the influx of Ly6Clow and Ly6Chigh monocytes, plus neutrophils and T cells. This vascular storm was associated with elevated levels of the adhesion molecules ICAM and VCAM and the pattern-recognition receptors TLR7 and TLR9 in the vascular wall, resulting in profound vascular dysfunction. The sequalae of this IAV-driven vascular storm included placental growth retardation and intrauterine growth restriction, evidence of placental and fetal brain hypoxia, and increased circulating cell free fetal DNA and soluble Flt1. In contrast, IAV infection in nonpregnant mice caused no obvious alterations in endothelial function or vascular inflammation. Therefore, IAV infection during pregnancy drives a significant systemic vascular alteration in pregnant dams, which likely suppresses critical blood flow to the placenta and fetus. This study in mice provides a fundamental mechanistic insight and a paradigm into how an immune response to a respiratory virus, such as IAV, is likely to specifically drive maternal and fetal pathologies during pregnancy.


Subject(s)
Adaptive Immunity/genetics , Immunity, Innate/genetics , Inflammation/genetics , Influenza A virus/genetics , Animals , Blood Vessels/metabolism , Blood Vessels/pathology , Female , Fetus/immunology , Humans , Inflammation/immunology , Inflammation/pathology , Inflammation/virology , Influenza A virus/pathogenicity , Influenza, Human/genetics , Influenza, Human/immunology , Influenza, Human/virology , Membrane Glycoproteins/genetics , Mice , Monocytes/metabolism , Monocytes/pathology , Placenta/blood supply , Placenta/immunology , Placenta/virology , Pregnancy , T-Lymphocytes/immunology , T-Lymphocytes/virology , Toll-Like Receptor 7/genetics , Toll-Like Receptor 9/genetics
14.
Rev Mal Respir ; 36(8): 924-936, 2019 Oct.
Article in French | MEDLINE | ID: mdl-31522950

ABSTRACT

INTRODUCTION: In France, long-term follow-up after occupational exposure to asbestos is recommended. This study looked at the psychological consequences in the longer term following a CT-scan, in particular the impact of having received compensation for an occupational disease. METHODS: As part of an asbestos post-exposure survey study (APExS), volunteers from Normandy were asked to complete self-assessment questionnaires about their psychological condition at different points during follow-up, including a psychological questionnaire before, then 6 months, and finally 18 to 24 months after their chest CT-scan. Information collected from 622 individuals were analyzed based on information provided as to the result of the screening and whether they had received compensation for having an occupational disease. RESULTS: The identification of an occupational disease eligible for compensation is associated with a long term increase in psychological distress. The impact of psychological state during follow-up is greater in men who reported receiving occupational disease compensation. The discovery of an asbestos-related disease during the screening is associated with a negative perception of general health and an increase in psychological distress. CONCLUSION: The receipt of compensation of an occupational disease does not seem to compensate for the negative psychological impact related to the discovery of a disease during the asbestos post-exposure follow-up.


Subject(s)
Asbestos/toxicity , Asbestosis/psychology , Occupational Exposure/adverse effects , Stress, Psychological/etiology , Workers' Compensation , Adult , Aged , Aged, 80 and over , Asbestosis/diagnosis , Cohort Studies , Female , France , Health Status , Humans , Male , Middle Aged , Radiography, Thoracic , Surveys and Questionnaires
15.
Paediatr Respir Rev ; 30: 34-41, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30201135

ABSTRACT

Inflammation of the preterm lungs is key to the pathogenesis of bronchopulmonary dysplasia (BPD), whether it arises as a consequence of intrauterine inflammation or postnatal respiratory management. This review explores steroidal and non-steroidal therapies for reducing neonatal pulmonary inflammation, aimed at treating or preventing BPD.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Bronchopulmonary Dysplasia/drug therapy , Bronchopulmonary Dysplasia/immunology , Glucocorticoids/therapeutic use , Bronchopulmonary Dysplasia/physiopathology , Chorioamnionitis/immunology , Dexamethasone/therapeutic use , Female , Fetal Organ Maturity , Humans , Infant, Extremely Premature , Infant, Newborn , Infant, Premature , Inflammation , Interleukin 1 Receptor Antagonist Protein/therapeutic use , NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors , Neonatal Sepsis/immunology , Pentoxifylline/therapeutic use , Pregnancy , Prenatal Care
16.
Open Biol ; 8(9)2018 09 19.
Article in English | MEDLINE | ID: mdl-30232099

ABSTRACT

Cells interact with the extracellular environment by means of receptor molecules on their surface. Receptors can bind different ligands, leading to the formation of receptor-ligand complexes. For a subset of receptors, called receptor tyrosine kinases, binding to ligand enables sequential phosphorylation of intra-cellular residues, which initiates a signalling cascade that regulates cellular function and fate. Most mathematical modelling approaches employed to analyse receptor signalling are deterministic, especially when studying scenarios of high ligand concentration or large receptor numbers. There exist, however, biological scenarios where low copy numbers of ligands and/or receptors need to be considered, or where signalling by a few bound receptor-ligand complexes is enough to initiate a cellular response. Under these conditions stochastic approaches are appropriate, and in fact, different attempts have been made in the literature to measure the timescales of receptor signalling initiation in receptor-ligand systems. However, these approaches have made use of numerical simulations or approximations, such as moment-closure techniques. In this paper, we study, from an analytical perspective, the stochastic times to reach a given signalling threshold for two receptor-ligand models. We identify this time as an extinction time for a conveniently defined auxiliary absorbing continuous time Markov process, since receptor-ligand association/dissociation events can be analysed in terms of quasi-birth-and-death processes. We implement algorithmic techniques to compute the different order moments of this time, as well as the steady-state probability distribution of the system. A novel feature of the approach introduced here is that it allows one to quantify the role played by each kinetic rate in the timescales of signal initiation, and in the steady-state probability distribution of the system. Finally, we illustrate our approach by carrying out numerical studies for the vascular endothelial growth factor and one of its receptors, the vascular endothelial growth factor receptor of human endothelial cells.


Subject(s)
Receptor Protein-Tyrosine Kinases/chemistry , Receptor Protein-Tyrosine Kinases/metabolism , Algorithms , Humans , Kinetics , Ligands , Markov Chains , Phosphorylation , Receptors, Vascular Endothelial Growth Factor/chemistry , Receptors, Vascular Endothelial Growth Factor/metabolism , Signal Transduction , Stochastic Processes , Vascular Endothelial Growth Factor A/chemistry , Vascular Endothelial Growth Factor A/metabolism
17.
Rev Mal Respir ; 35(7): 759-775, 2018 Sep.
Article in French | MEDLINE | ID: mdl-30097294

ABSTRACT

Bronchial challenge with the direct bronchoconstrictor agent methacholine is commonly used for the diagnosis of asthma. The "Lung Function" thematic group of the French Pulmonology Society (SPLF) elaborated a series of guidelines for the performance and the interpretation of methacholine challenge testing, based on French clinical guideline methodology. Specifically, guidelines are provided with regard to the choice of judgment criteria, the management of deep inspirations, and the role of methacholine bronchial challenge in the care of asthma, exercise-induced asthma, and professional asthma.


Subject(s)
Asthma/diagnosis , Bronchial Provocation Tests/methods , Bronchial Provocation Tests/standards , Bronchoconstrictor Agents/pharmacology , Methacholine Chloride/pharmacology , Asthma, Exercise-Induced/diagnosis , Bronchial Hyperreactivity/diagnosis , France , Humans , Plethysmography/methods , Plethysmography/standards , Respiratory Function Tests/methods , Respiratory Function Tests/standards , Spirometry/methods , Spirometry/standards
18.
Nat Commun ; 9(1): 2618, 2018 07 05.
Article in English | MEDLINE | ID: mdl-29976994

ABSTRACT

The T-cell antigen receptor (TCR) is pre-organised in oligomers, known as nanoclusters. Nanoclusters could provide a framework for inter-TCR cooperativity upon peptide antigen-major histocompatibility complex (pMHC) binding. Here we have used soluble pMHC oligomers in search for cooperativity effects along the plasma membrane plane. We find that initial binding events favour subsequent pMHC binding to additional TCRs, during a narrow temporal window. This behaviour can be explained by a 3-state model of TCR transition from Resting to Active, to a final Inhibited state. By disrupting nanoclusters and hampering the Active conformation, we show that TCR cooperativity is consistent with TCR nanoclusters adopting the Active state in a coordinated manner. Preferential binding of pMHC to the Active TCR at the immunological synapse suggests that there is a transient time frame for signal amplification in the TCR, allowing the T cells to keep track of antigen quantity and binding time.


Subject(s)
Histocompatibility Antigens/immunology , Peptides/immunology , Receptors, Antigen, T-Cell/immunology , T-Lymphocytes/immunology , Animals , Binding Sites , Histocompatibility Antigens/chemistry , Histocompatibility Antigens/metabolism , Humans , Immunological Synapses/immunology , Immunological Synapses/metabolism , Mice, Transgenic , Models, Molecular , Peptides/chemistry , Peptides/metabolism , Protein Binding , Protein Conformation , Protein Multimerization , Receptors, Antigen, T-Cell/chemistry , Receptors, Antigen, T-Cell/metabolism , Signal Transduction/immunology , T-Lymphocytes/metabolism
19.
J Thromb Haemost ; 16(3): 481-489, 2018 03.
Article in English | MEDLINE | ID: mdl-29274254

ABSTRACT

Essentials An immediate supply of plasma in case of trauma-induced coagulopathy is required. The Traucc trial compared French Lyophilised Plasma (FLyP) and Fresh Frozen Plasma (FFP). FLyP achieved higher fibrinogen concentrations compared with FFP. FLyP led to a more rapid coagulopathy improvement than FFP. SUMMARY: Background Guidelines recommend beginning hemostatic resuscitation immediately in trauma patients. We aimed to investigate if French lyophilized plasma (FLyP) was more effective than fresh frozen plasma (FFP) for the initial management of trauma-induced coagulopathy. Methods In an open-label, phase 3, randomized trial (NCT02750150), we enrolled adult trauma patients requiring an emergency pack of 4 plasma units within 6 h of injury. We randomly assigned patients to receive 4-FLyP units or 4-FFP units. The primary endpoint was fibrinogen concentration at 45 min after randomization. Secondary outcomes included time to transfusion, changes in hemostatic parameters at different time-points, blood product requirements and 30-day in-hospital mortality. Results Forty-eight patients were randomized (FLyP, n = 24; FFP, n = 24). FLyP reduced the time from randomization to transfusion of first plasma unit compared with FFP (median[IQR],14[5-30] vs. 77[64-90] min). FLyP achieved a higher fibrinogen concentration 45 min after randomization compared with FFP (baseline-adjusted mean difference, 0.29 g L-1 ; 95% confidence interval [CI], 0.08-0.49) and a greater improvement in prothrombin time ratio, factor V and factor II. The between-group differences in coagulation parameters remained significant at 6 h. FLyP reduced fibrinogen concentrate requirements. Thirty-day in-hospital mortality rate was 22% with FLyP and 29% with FFP. Conclusion FLyP led to a more rapid, pronounced and extended increase in fibrinogen concentrations and coagulopathy improvement compared with FFP in the initial management of trauma patients. FLyP represents an attractive option for trauma management, especially when facing logistical issues such as combat casualties or mass casualties related to terror attacks or disasters.


Subject(s)
Blood Coagulation Disorders/therapy , Blood Transfusion/methods , Fibrinogen/chemistry , Plasma/chemistry , Wounds and Injuries/therapy , Adult , Blood Coagulation , Blood Coagulation Disorders/etiology , Emergency Medicine/methods , Female , Fibrinogen/biosynthesis , France , Freeze Drying , Hemostatics , Humans , Male , Middle Aged , Resuscitation , Wounds and Injuries/complications
20.
Int J Tuberc Lung Dis ; 21(11): 1194-1200, 2017 11 01.
Article in English | MEDLINE | ID: mdl-29037302

ABSTRACT

BACKGROUND: Atopy has emerged as a major determinant of airway inflammation. OBJECTIVE: To examine whether early markers of occupational asthma increase with degree of sensitisation. METHOD: This study was a prospective follow-up study of apprentices in baking, pastry-cooking and hairdressing during their 2-year apprenticeship. Four visits were conducted to administer a standardised questionnaire, a methacholine challenge test to assess bronchial hyperresponsiveness (BHR) and to measure fractional exhaled nitric oxide (FeNO). Degree of sensitisation was estimated based on the number of positive skin prick tests (SPTs) for 12 common allergens. Mixed-effect models were applied to examine the association between the degree of sensitisation and FeNO levels, BHR and eosinophilic status (more than 3% of cells in nasal lavage fluid). RESULTS: Of the 441 apprentices who agreed to take part in the study, 417 had at least one SPT session providing usable results. Degree of sensitization was related to BHR and FeNO levels. Compared to non-sensitised subjects, FeNO levels were 83% higher (P < 0.01) in highly sensitised subjects and 30% higher (P < 0.01) in weakly sensitised subjects. However, the degree of sensitisation was not predictive of the evolution of these markers. CONCLUSION: Degree of sensitisation is related to early markers of airway inflammation.


Subject(s)
Asthma, Occupational/diagnosis , Bronchial Hyperreactivity/diagnosis , Inflammation/diagnosis , Nitric Oxide/metabolism , Adolescent , Allergens/immunology , Asthma, Occupational/epidemiology , Asthma, Occupational/immunology , Biomarkers/metabolism , Bronchial Hyperreactivity/epidemiology , Bronchial Hyperreactivity/immunology , Bronchial Provocation Tests , Female , Follow-Up Studies , Humans , Inflammation/epidemiology , Inflammation/immunology , Male , Prospective Studies , Skin Tests , Surveys and Questionnaires
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