Hémosidérose pulmonaire indiopathique et trisomie 21

ANGERS-BU Médecine-Pharmacie (490072105) / SudocSudocFranceF

Pratique du vaccin antituberculeux intradermique, chez l'enfant, par les médecins généralistes (Enquête auprès de 135 praticiens du Maine et Loire)

La vaccination antituberculeuse généralisée est obligatoire en France. L'incidence de la maladie y est faible et cette politique vaccinale est discutée. Depuis janvier 2006, seul est disponible le vaccin BCG (Bacille de Calmette et Guérin) intradermique (ID), délicat à réaliser. Notre enquête, de mai/juin 2006, auprès de 135 généralistes du Maine et Loire, évaluait leur pratique du BCG, leurs réticences et leur formation. Un généraliste sur deux avait abandonné l'usage du BCG depuis le retrait de la forme multipuncture. Pour 59,5 % d'entre eux, l'influence des publications en faveur d'une possible levée de l'obligation était un motif de non réalisation du BCG. A 78,5 %, ils n'adhéraient pas au principe de la vaccination généralisée. Par contre, 83 % estimaient que le vaccin était nécessaire pour les populations plus exposées à la tuberculose, et 44,8 % pensaient suivre de tels patients. Les praticiens ont mis en avant la difficulté de la technique ID chez l'enfant à 77,5 % et la crainte des effets indésirables à 73 %. Ces réticences révélaient que la balance bénéfice/risque du BCG ID ne paraissait plus favorable à la population générale. Leur formation, souvent ancienne, peu mise en pratique, montrait quelques insuffisances. Le manque d'adhésion à la vaccination antituberculeuse généralisée semblait participer à son recul. Néanmoins, le vaccin a prouvé son efficacité pour la protection des enfants à risque, définis essentiellement par leurs origines géographiques ou un possible contage. La vaccination ciblée basée sur l'évaluation individuelle systématique de sa pertinence, associant la famille à la décision, semblerait plus conforme aux pratiques médicales actuelles.ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

In vitro study of RNA encapsidation by the nucleoprotein of human Respiratory Syncytial Virus

Respiratory syncytial virus (RSV) has a negative-sense single-stranded RNA genome constitutively encapsidated by the viral nucleoprotein N, forming a helical nucleocapsid which is the template for viral transcription and replication by the viral polymerase L. Recruitment of L onto the nucleocapsid depends on the viral phosphoprotein P, which is an essential L cofactor. A prerequisite for genome and antigenome encapsidation is the presence of the monomeric, RNA-free, neosynthesised N protein, named N 0. Stabilisation of N 0 depends on the binding of the N-terminal residues of P to its surface, that prevents N oligomerisation. However, the mechanism involved in the transition from N 0-P to nucleocapsid assembly, and thus in the specificity of viral genome encapsidation, is still unknown. Furthermore, although the interaction between P and N complexed to RNA has been shown to be responsible for the morphogenesis of viral factories, where viral transcription and replication occur, the specific role of N oligomerisation and RNA in this process has not been elucidated. In the present study, using a chimeric protein between N and the first 40 N-terminal residues of P, we succeeded in purifying a recombinant N 0-like protein competent for RNA encapsidation in vitro. Our results showed the importance of RNA length for stable encapsidation and revealed differences in encapsidation depending on the nature of the 5' end, without any specificity for RNA sequence. Finally, we showed that RNA encapsidation is crucial for the in vitro reconstitution of pseudo-viral factories

In vitro study of RNA encapsidation by the nucleoprotein of human Respiratory Syncytial Virus

Respiratory syncytial virus (RSV) has a negative-sense single-stranded RNA genome constitutively encapsidated by the viral nucleoprotein N, forming a helical nucleocapsid which is the template for viral transcription and replication by the viral polymerase L. Recruitment of L onto the nucleocapsid depends on the viral phosphoprotein P, which is an essential L cofactor. A prerequisite for genome and antigenome encapsidation is the presence of the monomeric, RNA-free, neosynthesised N protein, named N 0. Stabilisation of N 0 depends on the binding of the N-terminal residues of P to its surface, that prevents N oligomerisation. However, the mechanism involved in the transition from N 0-P to nucleocapsid assembly, and thus in the specificity of viral genome encapsidation, is still unknown. Furthermore, although the interaction between P and N complexed to RNA has been shown to be responsible for the morphogenesis of viral factories, where viral transcription and replication occur, the specific role of N oligomerisation and RNA in this process has not been elucidated. In the present study, using a chimeric protein between N and the first 40 N-terminal residues of P, we succeeded in purifying a recombinant N 0-like protein competent for RNA encapsidation in vitro. Our results showed the importance of RNA length for stable encapsidation and revealed differences in encapsidation depending on the nature of the 5' end, without any specificity for RNA sequence. Finally, we showed that RNA encapsidation is crucial for the in vitro reconstitution of pseudo-viral factories

In vitro study of RNA encapsidation by the nucleoprotein of human Respiratory Syncytial Virus

Respiratory syncytial virus (RSV) has a negative-sense single-stranded RNA genome constitutively encapsidated by the viral nucleoprotein N, forming a helical nucleocapsid which is the template for viral transcription and replication by the viral polymerase L. Recruitment of L onto the nucleocapsid depends on the viral phosphoprotein P, which is an essential L cofactor. A prerequisite for genome and antigenome encapsidation is the presence of the monomeric, RNA-free, neosynthesised N protein, named N 0. Stabilisation of N 0 depends on the binding of the N-terminal residues of P to its surface, that prevents N oligomerisation. However, the mechanism involved in the transition from N 0-P to nucleocapsid assembly, and thus in the specificity of viral genome encapsidation, is still unknown. Furthermore, although the interaction between P and N complexed to RNA has been shown to be responsible for the morphogenesis of viral factories, where viral transcription and replication occur, the specific role of N oligomerisation and RNA in this process has not been elucidated. In the present study, using a chimeric protein between N and the first 40 N-terminal residues of P, we succeeded in purifying a recombinant N 0-like protein competent for RNA encapsidation in vitro. Our results showed the importance of RNA length for stable encapsidation and revealed differences in encapsidation depending on the nature of the 5' end, without any specificity for RNA sequence. Finally, we showed that RNA encapsidation is crucial for the in vitro reconstitution of pseudo-viral factories

Selective IgG subclass deficiency in children with recurrent infections : clinical, biological and therapeutic relevance

Date du colloque&nbsp;: 10/2008</p

New insights into pediatric idiopathic pulmonary hemosiderosis: the French RespiRare(R) cohort.

International audienceBACKGROUND: Idiopathic pulmonary hemosiderosis (IPH) is a rare cause of alveolar hemorrhage in children and its pathophysiology remains obscure. Classically, diagnosis is based on a triad including hemoptysis, diffuse parenchymal infiltrates on chest X-rays, and iron-deficiency anemia. We present the French pediatric cohort of IPH collected through the French Reference Center for Rare Lung Diseases (RespiRare(R), www.respirare.fr). METHODS: Since 2008, a national network/web-linked RespiRare(R) database has been set up in 12 French pediatric respiratory centres. It is structured as a medical recording tool with extended disease-specific datasets containing clinical information relevant to all forms of rare lung diseases including IPH. RESULTS: We identified 25 reported cases of IPH in children from the database (20 females and 5 males). Among them, 5 presented with Down syndrome. Upon diagnosis, median age was 4.3 [0.8-14.0] yrs, and the main manifestations were: dyspnea (n = 17, 68%), anemia (n = 16, 64%), cough (n = 12, 48%), febrile pneumonia (n = 11, 44%) and hemoptysis (n = 11, 44%). Half of the patients demonstrated diffuse parenchymal infiltrates on chest imaging, and diagnosis was ascertained either by broncho-alveolar lavage indicating the presence of hemosiderin-laden macrophages (19/25 cases), or lung biopsy (6/25). In screened patients, initial auto-immune screening revealed positive ANCA (n = 6, 40%), ANA (n = 5, 45%) and specific coeliac disease antibodies (n = 4, 28%). All the patients were initially treated by corticosteroids. In 13 cases, immunosuppressants were introduced due to corticoresistance and/or major side effects. Median length of follow-up was 5.5 yrs, with a satisfactory respiratory outcome in 23/25 patients. One patient developed severe pulmonary fibrosis, and another with Down syndrome died as a result of severe pulmonary hemorrhage. CONCLUSION: The present cohort provides substantial information on clinical expression and outcomes of pediatric IPH. Analysis of potential contributors supports a role of auto-immunity in disease development and highlights the importance of genetic factors

Long-Term Rasamsonia argillacea Complex Species Colonization Revealed by PCR Amplification of Repetitive DNA Sequences in Cystic Fibrosis Patients

International audienc