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F Leclerc

Publications and source records attributed to F Leclerc.

At least 19 recordsLinked to original sources
PubMed2006

Analysis of sequence and structural features that identify the B/C motif of U3 small nucleolar RNA as the recognition site for the Snu13p-Rrp9p protein pair.

The eukaryal Snu13p/15.5K protein binds K-turn motifs in U4 snRNA and snoRNAs. Two Snu13p/15.5K molecules bind the nucleolar U3 snoRNA required for the early steps of preribosomal processing. Binding of one molecule on the C'/D motif allows association of proteins Nop1p, Nop56p, and Nop58p, whereas binding of the second molecule on the B/C motif allows Rrp9p recruitment. To understand how the Snu13p-Rrp9p pair recognizes the B/C motif, we first improved the identification of RNA determinants required for Snu13p binding by experiments using the systematic evolution of ligands by exponential enrichment. This demonstrated the importance of a U.U pair stacked on the sheared pairs and revealed a direct link between Snu13p affinity and the stability of helices I and II. Sequence and structure requirements for efficient association of Rrp9p on the B/C motif were studied in yeast cells by expression of variant U3 snoRNAs and immunoselection assays. A G-C pair in stem II, a G residue at position 1 in the bulge, and a short stem I were found to be required. The data identify the in vivo function of most of the conserved residues of the U3 snoRNA B/C motif. They bring important information to understand how different K-turn motifs can recruit different sets of proteins after Snu13p association.

Base Pairing↗
PubMed2006

[Evaluation of the antibiotic prescription in a paediatric intensive care unit].

UNLABELLED: The antibiotic prescription in intensive care units is frequent using often broad-spectrum antibiotics; its quality has never been evaluated in paediatric intensive care units. OBJECTIVES: To describe the modalities of antibiotic prescriptions in a paediatric intensive care unit and confront them to the literature guidelines and bacteriological data. METHODS: From January 1st to March 31st 2005, 52 consecutive prescriptions regarding 45 children, with a total of 47 hospitalisations were prospectively analysed. RESULTS: Confirmed diagnosis of bacterial infection was retained for 50 of the 52 patients: community acquired infection in 35 cases (70%) and a nosocomial infection in 15 cases. Ten children died during the antibiotic treatment (22%), with 5 deaths related to the infection (11%). Monotherapy represented 56% of the prescriptions of antibiotics. The initial antibiotic treatment was empirical in 42 of 52 cases (81%). The empirical prescriptions were documented afterward in 48% of cases. One or more microorganisms were isolated for 60% of the initial prescriptions. Misuses in antibiotic doses (in excess [10%] or by insufficiency [13%]), number of daily administration (4%), and way of administration and/or length of treatment were observed. Seventy-seven percent of the initial prescriptions seemed to be adapted to the identified or suspected bacteria, but only 63% adequate to recommendations. CONCLUSION: Almost 2/3rd of the antibiotic prescriptions were adequate to the recommendations. The implementation of standardized and specific protocols should contribute to improve the quality of these prescriptions.

Anti-Bacterial Agents↗
PubMed2006

[Non-invasive ventilation in infants with severe infection presumably due to respiratory syncytial virus: feasibility and failure criteria].

UNLABELLED: Beneficial effect of continuous positive airway pressure (CPAP) during non invasive ventilation (NIV) has been reported in infants with respiratory syncytial virus (RSV) infection, but no study has analyzed the predictors of its failure. OBJECTIVE: To evaluate the feasibility of NIV and to determine NIV failure criteria. POPULATION AND METHODS: All infants hospitalized in one PICU with presumed RSV infection between 2002 and 2006 were prospectively included. When respiratory support was needed, NIV was first started according to a pre-established protocol. RESULTS: One hundred and one infants, 43 females, 58 males, median age 49 days (range: 10-334), median weight 3.9 kg (range: 2,4-12) were included. RSV infection was confirmed in 84/101. Sixty-seven infants were transported by the paediatric medical transport system, 27 with NIV and 15 with invasive ventilation (IV). Fifteen infants were in IV at admission, 69 received NIV during their PICU stay (12 secondarily requiring IV) and 17 were never ventilated. A significant decrease in PCO2 with increase in pH was observed within 2 hours of NIV. Parameters associated with NIV failure were apneas, high values of admission PCO2 and H24 PRISM score. The 17 non-ventilated infants were older and had a lower severity score than those who were ventilated. CONCLUSION: In infants with RSV and needing respiratory support, NIV represented the sole method of respiratory support in 68% of cases. NIV failure criteria were apneas, high values of admission PCO2 and H24 PRISM score.

Child↗
PubMed2005

[Withholding or withdrawing life saving treatment in pediatric intensive care unit: GFRUP guidelines].

Several recent French studies have revealed that 40% of death in pediatric intensive care units are associated with withdrawal or limitation of life saving treatments. Because such decisions are common, the Groupe francophone de réanimation et urgences pédiatriques (GFRUP) has decided to publish recommendations in order to help paediatricians dealing with those difficult issues and to improve their decisions. In a first part of the document the ethical principles that imply those guidelines are recalled, followed by definitions of the terms currently employed. The second part contains guidelines regarding decision making process, the way it is applied and organisation of relatives as well as paramedical and medical staff support when the death of a child occurs.

Child↗
PubMed2004

Reproducibility of the respiratory dead space measurements in mechanically ventilated children using the CO2SMO monitor.

OBJECTIVES: To assess the reproducibility of respiratory dead space measurements in ventilated children. DESIGN: Prospective study. SETTING: University pediatric intensive care unit. PATIENTS: Thirty-two mechanically ventilated children (0.13-15.4 years) who were clinically stable. METHODS: The single-breath CO(2) test (SBT-CO(2)) was recorded using the CO(2)SMO Plus from the mean of 30 ventilatory cycles during 1 h (at T0, T15, T30, T45, and T60). Airway dead space was determined automatically (Novametrix Medical Systems, USA), and manually by Bohr- Enghoff equations using data obtained by SBT-CO(2). At the end of the study period, arterial blood gas was sampled in order to calculate alveolar and physiologic dead space. Intrasubject reproducibility of measurements was evaluated by the intraclass correlation coefficient. Two-way analysis of variance was used to evaluate the relationships between time and measurements. The two methods for calculating airway dead space were compared by using two-tailed Student's t-test and Bland-Altman analysis. RESULTS: Airway dead space measurement had a good reproducibility during the 1-h period, whatever the method used (intraclass correlation coefficient: 0.84 to 0.87). No significant difference was observed with time. Airway dead space values from the SBT-CO(2) method were smaller than those from Bohr-Enghoff equations. Physiologic dead space values from the SBT-CO2 method were similar to those from Bohr-Enghoff equations. CONCLUSION: The measurement of airway dead space by the CO(2)SMO Plus was reproducible over a 1-h period in children requiring mechanical ventilation, provided ventilatory parameters were constant throughout the study. SBT-CO(2) analysis may provide a bedside non-invasive monitoring of volumetric capnography.

Adolescent↗
PubMed2004

[Does selective digestive decontamination prevent nosocomial infections?].

Paediatric intensive care and haematological units are ideal sites for the development of nosocomial infections. These infections remain a significant source of mortality and morbidity and increase length of stay and costs. Selective digestive decontamination (SDD) includes topical antibiotics during the entire intensive care unit (ICU) stay, parenteral antibiotic administered for three to five days, hand hygiene and surveillance cultures of throat and rectum. Its use is based on the observation that resistant bacteria are often imported by the patients themselves, and the fact that transmission via the hands of carers could be responsible only for infections occurring after one week. In adult patients, seven meta-analyses have demonstrated that SDD reduces the odds ratio for lower airway infections, and sometimes mortality (particularly in surgical and trauma patients). The main criticism against SDD is the possible emergence of antibiotic resistant bacteria, which is a growing problem in Europe and United States of America. Only four studies on SDD in children have been reported in the literature: due to methodological weaknesses and small size of samples, definitive conclusion cannot be drawn. However, one study in a 20 bed paediatric intensive care unit has demonstrated that SDD prevent both infections and the emergence of resistant bacteria. Furthermore, it has been demonstrated that more than 50% of children carrying resistant bacteria are detected within 24 hours of admission, suggesting that they import the resistant strains onto the intensive care unit. Factors that predict facility, administration of i.v. antibiotics within the past 12 months, previous intensive care unit admission and hospitalization of a household contact within the past 12 months. As suggested by several authors, the term selective should mean selection of appropriate patient groups (those at high risk of nosocomial infection, e.g. patients mechanically ventilated for at least 48 hours) and units (excluding those where multiresistance is endemic). Obviously, surveillance of patient and unit bacterial ecology and improvement of antibiotic policy must be reinforced.

Anti-Bacterial Agents↗
PubMed2003

Admission plasma vasopressin levels in children with meningococcal septic shock.

OBJECTIVE: Vasopressin (AVP) response has been reported to be inappropriately low in adult established septic shock. We studied admission AVP levels in children with meningococcal septic shock (MSS). PATIENTS AND METHODS: All children with meningococcal infection admitted to our PICU between May 2001 and August 2002 were classified as MSS (persistent hypotension despite fluid therapy, with perfusion abnormalities and the need for vasoactive drug infusion for at least 24 h or until death), or meningococal infection without shock (fever and purpura, with or without meningitis). Blood samples were collected at admission and AVP levels were subsequently determined using Nichols Institute Diagnostics vasopressin assay. Eighteen of 19 children with MSS (7 deaths) and 15 without shock (no death) were included. RESULTS: In children with MSS median admission AVP level was 41.6 pg/ml (1.4-498.9) and in those without 3.3 pg/ml (1.6-63.8). In children with MSS the AVP level was not correlated with duration of shock and fluid expansion prior to AVP sampling, or with age-adjusted blood pressure and natremia at the time of blood sampling. AVP levels were higher in nonsurvivors, but not significantly so. Only one nonsurvivor had an admission AVP level below 30 pg/ml. CONCLUSIONS: In our children with established MSS who died the admission AVP level Delta were not inappropriately low. Further studies including serial AVP level assessments are needed before concluding that AVP administration is of little interest in children with MSS.

Child, Preschool↗
PubMed2003

Plastic bronchitis mimicking foreign body aspiration that needs a specific diagnostic procedure.

OBJECTIVE: To report two children admitted to our emergency department with respiratory failure, one for status asthmaticus with pneumomediastinum and requiring mechanical ventilation and the other for high suspicion of foreign body aspiration. INTERVENTIONS: Bronchoscopy revealed obstructive plugs and permitted their extraction and their identification as bronchial casts after the immersion in normal saline. Allergy was suspected in the first one, and Hemophilus influenzae infection was present in the second. The outcome was favorable. CONCLUSIONS: Plastic bronchitis is an infrequent cause of acute life-threatening respiratory failure that can mimic foreign body aspiration or status asthmaticus. Bronchoscopic extraction must be performed urgently in the case of severe obstruction. This entity is probably underestimated as the casts with their specific ramifications are difficult to recognize. We recommend the immersion in normal saline of all plugs discovered in children with predisposing diseases mainly represented by infections, allergy, acute chest syndrome, and congenital cardiopathies.

Acute Disease↗
PubMed2003

Role of viruses and atypical bacteria in exacerbations of asthma in hospitalized children: a prospective study in the Nord-Pas de Calais region (France).

We studied the role of viruses and atypical bacteria in children hospitalized with exacerbated asthma by a prospective study of children with acute asthma admitted to the Department of Pediatrics in Lille, and to 15 hospitals in the Nord-Pas de Calais region, from October 1, 1998-June 30, 1999. We included children aged 2-16 years with active asthma, defined as three or more recurrent episodes of reversible wheezing. The severity of asthma and of asthmatic exacerbations was recorded. Immunofluorescence assays (IFA) on nasopharyngeal secretions (NPS), serological tests, or both, were used for detection of influenza virus, respiratory syncytial virus (RSV), adenovirus, parainfluenza virus, and coronavirus. Polymerase chain reaction (PCR) assays on NPS were used for rhinovirus and enterovirus. Serological tests for Chlamydia pneumoniae and Mycoplasma pneumoniae were performed. A control group of asymptomatic asthmatic outpatients was examined for respiratory viruses (using IFA and PCR). Eighty-two symptomatic children (mean age, 7.9 years) were examined. Viruses were detected in 38% (enterovirus, 15.8%; rhinovirus, 12%; RSV, 7.3%). Serological tests for atypical bacteria were positive in 10% of patients (C. pneumoniae, 5%; M. pneumoniae, 5%). Among the 27 control subjects (mean age, 7.9 years), one PCR was positive for enterovirus. There was no correlation between severity of chronic asthma or asthmatic exacerbations and the diagnosis of infection. Atypical bacterial pathogen infections were linked with prolonged asthmatic symptoms. In conclusion, we confirmed the high incidence of viral infection in acute exacerbations of asthma, especially enteroviruses or rhinoviruses. Persistent clinical features were more frequently associated with atypical bacterial infections, suggesting that these infections should be investigated and treated in cases of persistent asthmatic symptoms.

Adolescent↗
PubMed2003

[Subcutaneous fat necrosis in the newborn: a risk for severe hypercalcemia].

Hypercalcemia associated with subcutaneous fat necrosis (SCN) is a well known but rare event in the newborn. A newborn infant with a history of SCN was admitted because of anorexia, adynamia, polyuria and polydipsia at 6 weeks of age. Serum calcium was markedly increased on admission, while it was normal on the first day of life. Evolution was favourable after treatment including isotonic saline solution, furosemide, corticosteroids, calcitonin and a low calcium and vitamin D diet. Hypercalcemia was severe enough to potentially induces fatal complications in this case. Neonates who develop skin lesions consistent with SCN should be followed-up for possible onset of hypercalcemia and treated in due time. The treatment of hypercalcemia in SCN is reviewed.

Fat Necrosis↗
PubMed2002

[Chiari type I malformation in children: presentation in 34 cases].

UNLABELLED: Incidental diagnoses of Chiari I malformation are more and more frequent in pauci or asymptomatic children. The value of neurophysiological investigations for surgical indications is discussed. OBJECTIVE: To determine clinical presentations of Chiari I malformation and relative frequencies of severe and incidental forms, and to evaluate the usefulness of neurophysiological investigations for surgical indications. METHODS: This retrospective study included 34 patients admitted from 1984 to 2000, with Chiari I malformation diagnosis in different pediatric (intensive care, neurology and neurosurgery) units of a university hospital. RESULTS: The clinical presentation was severe (two children died) in four cases (12%). Signs of brain stem compression were found in 41% of cases, scoliosis in 21%, and incidental diagnosis in 26%. The polysomnography, performed in 12 cases, showed sleep-apneas in six cases. One child with an incidental diagnosis of Chiari I malformation had many sleep-apneas which required a surgical treatment. A surgical decompression was performed in 69% of cases, with clinical improvement in 77%. CONCLUSION: The high incidence (12%) of severe forms revealing Chiari I malformations justifies systematic neurophysiological investigations for the initial evaluation and the follow-up of Chiari 1 malformations, including the less symptomatic forms.

Adolescent↗
PubMed2002

[Life-threatening Plasmodium falciparum parasitemia, in an infant returning from the tropics].

INTRODUCTION: Severe falciparum malaria is a polymorphous life-threatening disease. Hyperparasitemia is rare among non-immune children returning from tropical areas. CARE REPORT: We report a case of an infant returning from Ivory Coast who presented with fever, prostration and marked thrombocytopenia (22,000 platelets/mm(3)). Blood slide showed Plasmodium falciparum ring forms. Parasite density dramatically increased from 1.7% to 45%, and the child developed several features of severe malaria, according to WHO definition. CONCLUSION: In this non-immune infant, prostration and thrombopocytopenia seemed to be earlier predictors of severity than hyperparasitemia and other WHO criteria, which have not been yet validated in travelling children.

Animals↗
PubMed2002

[Fatal intoxication after accidental ingestion of viscous 2% lidocaine in a young child].

We report a case of fatal intoxication with 2% viscous lidocaine. A 18 month old infant was admitted after malaise and cardiorespiratory arrest at home. He was resuscitated, then seizures appeared before arrival at the hospital. Treatment was symptomatic, including cardiorespiratory resuscitation and administration of anticonvulsants. Identification of lidocaine and its metabolite monoethylglycinexylidide (MEGX) MEGX was performed after organic extraction by High Performance Liquid Chromatography (HPLC) with Diode Array Detection (DAD); the serum concentrations, determined by Fluorescence Polarisation Immuno Assay (FPIA), were: 1.1 micrograms/ml for lidocaine and 0.94 microgram/ml for MEGX (H + 7) and 0.30 microgram/ml for the lidocaine (Day + 1). Neurotoxic manifestations appear at lower concentrations than cardiotoxic symptoms which are correlated with plasma levels of lidocaine. The toxic symptoms begin with headache, hallucinations, seizure, coma, respiratory arrest and circulatory collapse. The toxic symptoms can persist even after the decrease of lidocaine concentration under therapeutic levels. There is no antidote and acute lidocaine toxicity is managed with supportive therapy (diazepam for seizures, intubation, chronotropic agents). Considering the gravity of these poisonings which remain rare, the 2% viscous lidocaine prescription is forbidden for children under 6 years old.

Administration, Oral↗
PubMed2001

[Purpura fulminans and coxsackie B2 co-infection].

INTRODUCTION: During septic shock in children, myocardial deficiency usually lasts 3 to 6 days. When prolonged, an other etiology should be looked for. OBSERVATION: A 29 month-old child presented with purpura fulminans, probably due to Neisseria meningitidis. Positivity of the serodiagnostic for coxsackie B2, performed because of persisting myocardial deficiency, evoked diagnosis of a coxsackie B2 co-infection. DISCUSSION: Abnormally prolonged myocardial deficiency during purpura fulminans must lead to the search for a congenital, metabolic or infectious cardiomyopathy.

Child, Preschool↗