Intercomparison of methods of coupling between convection and large-scale circulation: 2. Comparison over nonuniform surface conditions.

As part of an international intercomparison project, the weak temperature gradient (WTG) and damped gravity wave (DGW) methods are used to parameterize large-scale dynamics in a set of cloud-resolving models (CRMs) and single column models (SCMs). The WTG or DGW method is implemented using a configuration that couples a model to a reference state defined with profiles obtained from the same model in radiative-convective equilibrium. We investigated the sensitivity of each model to changes in SST, given a fixed reference state. We performed a systematic comparison of the WTG and DGW methods in different models, and a systematic comparison of the behavior of those models using the WTG method and the DGW method. The sensitivity to the SST depends on both the large-scale parameterization method and the choice of the cloud model. In general, SCMs display a wider range of behaviors than CRMs. All CRMs using either the WTG or DGW method show an increase of precipitation with SST, while SCMs show sensitivities which are not always monotonic. CRMs using either the WTG or DGW method show a similar relationship between mean precipitation rate and column-relative humidity, while SCMs exhibit a much wider range of behaviors. DGW simulations produce large-scale velocity profiles which are smoother and less top-heavy compared to those produced by the WTG simulations. These large-scale parameterization methods provide a useful tool to identify the impact of parameterization differences on model behavior in the presence of two-way feedback between convection and the large-scale circulation.

Intercomparison of methods of coupling between convection and large-scale circulation: 1. Comparison over uniform surface conditions.

As part of an international intercomparison project, a set of single-column models (SCMs) and cloud-resolving models (CRMs) are run under the weak-temperature gradient (WTG) method and the damped gravity wave (DGW) method. For each model, the implementation of the WTG or DGW method involves a simulated column which is coupled to a reference state defined with profiles obtained from the same model in radiative-convective equilibrium. The simulated column has the same surface conditions as the reference state and is initialized with profiles from the reference state. We performed systematic comparison of the behavior of different models under a consistent implementation of the WTG method and the DGW method and systematic comparison of the WTG and DGW methods in models with different physics and numerics. CRMs and SCMs produce a variety of behaviors under both WTG and DGW methods. Some of the models reproduce the reference state while others sustain a large-scale circulation which results in either substantially lower or higher precipitation compared to the value of the reference state. CRMs show a fairly linear relationship between precipitation and circulation strength. SCMs display a wider range of behaviors than CRMs. Some SCMs under the WTG method produce zero precipitation. Within an individual SCM, a DGW simulation and a corresponding WTG simulation can produce different signed circulation. When initialized with a dry troposphere, DGW simulations always result in a precipitating equilibrium state. The greatest sensitivities to the initial moisture conditions occur for multiple stable equilibria in some WTG simulations, corresponding to either a dry equilibrium state when initialized as dry or a precipitating equilibrium state when initialized as moist. Multiple equilibria are seen in more WTG simulations for higher SST. In some models, the existence of multiple equilibria is sensitive to some parameters in the WTG calculations.

Analytical methods for measuring collagen XIX in human cell cultures, tissue extracts, and biological fluids.

Type XIX collagen is a minor collagen associated with basement membranes in vascular, neuronal, mesenchymal, and epithelial tissues. We demonstrated that the NC1, C-terminal, domain of collagen XIX inhibits the migration capacities of tumor cells and exerts a strong inhibition of tumor growth. Other basement membrane collagens or derived fragments were measured in biological fluids such as blood and urine of patients and appeared to be useful for diagnosis, prognosis, or treatment monitoring. The aim of this study was to develop and validate methods to measure collagen XIX and its fragments in human cell cultures, tissue extracts, and human biological fluids. For that purpose, we developed real-time PCR, Western blot, and competitive enzyme-linked immunosorbent assays. We demonstrated that the methods developed in this paper are specific for collagen XIX. We showed that it is expressed in human cell cultures, tissue extracts, and various biological fluids. These methods may be used in various human tissue extracts and biological fluids such as serum, amniotic fluid, cord blood, and many other fluids. Collagen XIX or its fragments could constitute new biomarkers for human diseases as well as for diagnosis and/or prognosis.

[Late onset Ondine syndrome: literature review on a case report]. / Syndrome d'Ondine à révélation tardive : revue de la littérature à propos d'un cas.

Ondine syndrome is the central congenital hypoventilation syndrome (CCHS) caused by the mutation of the PHOX2B gene. In late onset cases, the symptomatology often appears after an acute event (infection, general anesthesia, drug intake), increasing hypoventilation. We report a case of late onset Ondine curse in a 9-year-old girl. The diagnosis was made based on a hypercapnic coma complicating a respiratory infection caused by Mycoplasma pneumoniae and was confirmed by genetic testing. In the patient's history we found symptoms that had not been noted (e.g., enuresis, morning headache, adynamia), attesting to chronic hypoventilation. Through this observation, we review the literature on CCHS, notably late onset cases, which are rare and insidious, emphasizing the pre-existing hypoventilation symptoms in this child. This case underlines the need for all practitioners not to trivialize these symptoms so as to decrease the current delay in diagnosis for late onset CCHS and to introduce optimal care as soon as possible.

[Cystic fibrosis: centers and care networks organization]. / Mucoviscidose: organisation de la prise en charge.

More than 20 years after the gene discovery, without specific treatment, the observed improvement of the cystic fibrosis prognosis appears due to management's organization as well as early diagnosis (neonatal screening) or progress in symptomatic treatment. The CF Centers (CRCM) official recognition was a necessary step before generalization of routine neonatal screening (October, 2002). Actually French CF management relies on three levels of organization: CF centers, regional care networks and French CF Society, in close relationship with patients association (Vaincre la Mucoviscidose).

[Intrafamilial transmission of Staphylococcus aureus Panton-Valentine leukocidin responsible for two cases of neonatal necrotizing pneumonia]. / Transmission intrafamiliale de Staphylococcus aureus sécréteur de toxine leucocidine Panton-Valentine responsable de deux cas de pneumopathies nécrosantes néonatales.

Necrotizing Staphylococcus aureus Panton-Valentine leukocidin (SA-PLV+) accounts for less than 1% of community-acquired lung diseases in children and young adults. Neonatal cases are exceptional. We report the observations of two newborn female twins, who were not breastfed, presenting a necrotizing lung disease due to the same strain of SA-PVL+ despite nasal decolonization measures taken. These two cases are informative and bring to light (1) the possibility of severe SA-PVL+ lung infections in young infants and (2) their strictly intrafamilial mode of transmission for which eradication measures were ineffective.

[Granulomatous pulmonary involvement preceding diagnosis of Crohn disease: a pediatric case report]. / Atteinte granulomateuse pulmonaire précédant le diagnostic de maladie de Crohn: à propos d'un cas pédiatrique.

Crohn disease (CD) is a chronic bowel disorder that may affect many other organs such as the eyes, hepatobiliary system, skin, and joints. Pulmonary involvement in association with CD is a classic but uncommon manifestation. It can be primitive with granulomas or secondary to treatments. We report on the case of a teenager in whom the onset of CD was dominated by respiratory symptoms. Because of this presentation, we also suspected opportunistic infections such as tuberculosis and other granulomatous pulmonary diseases such as sarcoidosis or hypersensitivity pneumonitis.

The very low penetrance of cystic fibrosis for the R117H mutation: a reappraisal for genetic counselling and newborn screening.

BACKGROUND: Cystic fibrosis (CF) is caused by compound heterozygosity or homozygosity of CF transmembrane conductance regulator gene (CFTR) mutations. Phenotypic variability associated with certain mutations makes genetic counselling difficult, notably for R117H, whose disease phenotype varies from asymptomatic to classical CF. The high frequency of R117H observed in CF newborn screening has also introduced diagnostic dilemmas. The aim of this study was to evaluate the disease penetrance for R117H in order to improve clinical practice. METHODS: The phenotypes in all individuals identified in France as compound heterozygous for R117H and F508del, the most frequent CF mutation, were described. The allelic prevalences of R117H (p(R117H)), on either intron 8 T5 or T7 background, and F508del (p(F508del)) were determined in the French population, to permit an evaluation of the penetrance of CF for the [R117H]+[F508del] genotype. RESULTS: Clinical details were documented for 184 [R117H]+[F508del] individuals, including 72 newborns. The disease phenotype was predominantly mild; one child had classical CF, and three adults' severe pulmonary symptoms. In 5245 healthy adults, p(F508del) was 1.06%, p(R117H;T7) 0.27% and p(R117H;T5)<0.01%. The theoretical number of [R117H;T7]+[F508del] individuals in the French population was estimated at 3650, whereas only 112 were known with CF related symptoms (3.1%). The penetrance of classical CF for [R117H;T7]+[F508del] was estimated at 0.03% and that of severe CF in adulthood at 0.06%. CONCLUSIONS: These results suggest that R117H should be withdrawn from CF mutation panels used for screening programmes. The real impact of so-called disease mutations should be assessed before including them in newborn or preconceptional carrier screening programmes.

RISA-HPLC analysis of lung bacterial colonizers of cystic fibrosis children.

Microbiological analysis of sputum samples, from children affected by cystic fibrosis (CF) and showing signs of acute or chronic infections, is routinely performed by culture-dependent approaches involving selective media and biochemical tests. These identification schemes are time-consuming, and may lead to false negative results. The aim of this work was to evaluate the efficacy of a Ribosomal Intergenic Spacer Analysis (RISA) coupled to high performance liquid chromatography (HPLC) for the detection and monitoring of CF lung microbial colonizers including Staphylococcus aureus, Haemophilus influenzae, Pseudomonas aeruginosa, the Burkholderia cepacia complex, Stenotrophomonas maltophilia, and Achromobacter xylosoxidans. These RISA-HPLC analyses were performed over a 10-months period on infants (below 18 months) and children that were or were not yet known to be colonised by P. aeruginosa. The RISA-HPLC profiles were found specific of the patients' microbial communities. A specific P. aeruginosa RISA-HPLC peak corresponding to 550 bp PCR products was recorded, and used to investigate P. aeruginosa persistence through time and after various therapeutic treatments. The RISA-HPLC profiles showed the CF children to be colonized by few bacterial species, and sometimes revealed peaks corresponding to bacterial species that were not detected by the selective plating approaches. Significant RISA-HPLC infra-specific variations were observed for most bacterial colonizers of CF lungs except P. aeruginosa. These species could yield as much as 5 distinct RISA-HPLC peaks, with some of these profiles being strain-specific. RISA-HPLC shows a great potential for revealing colonization by novel emerging pathogens, and for evaluating the efficacy of therapeutic treatments on the global bacterial community of CF lungs.

[Capnocytophaga sputigena pleuropneumonitis: a case report]. / Pleuropneumopathie àCapnocytophaga sputigena : à propos d'un cas.

Community-acquired pneumonia is complicated by purulent pleural effusion in approximately 28% of affected children. Its incidence has increased over the last decade. Streptococcus pneumoniae is the most frequent causal microorganism, encountered in roughly 80% of cases. We report the case of an immunocompetent 13-year-old teenager wearing orthodontic braces who suffered from pleuropneumonia due to Capnocytophaga sputigena. To date, this Gram-negative bacillus, a commensal of the buccal cavity, had never been reported to be responsible for pleural or lung infection. The clinical presentation is similar to that observed with usual bacteria, while bacterial sensitivity to betalactam antibiotics is excellent.

Effectiveness of home treatment for patients with cystic fibrosis: the intravenous administration of antibiotics to treat respiratory infections.

Patients with cystic fibrosis (CF) experience repeated infectious respiratory exacerbations leading to a continuous decline in lung function. The exacerbations are treated in hospital or at home. Our aim was to compare the clinical outcome for patients undergoing intravenous antibiotic treatment either in hospital or at home. A retrospective 10-year study was performed in four regional CF Centers. The outcome measures were percentage changes in forced expiratory volume in 1 sec (FEV(1)), forced vital capacity (FVC) and weight for age z-score (WZS). FEV(1), FVC, and WZS changes were calculated for the entire study period and for each course. A total of 1,164 courses were analyzed. For each course, the mean improvement in FEV(1) and FVC was significantly higher when performed in hospital than when performed at home (P < 0.05). FEV(1) and FVC values were 10.2%, 9.5% respectively in the hospital group and 7.3%, 6.8% in the home group. A total of 153 patients were analyzed (51 inpatients matched to 102 patients treated at home). The two groups had no significant differences in any outcome variable at baseline. The mean variation per year in FEV(1) was greater in the hospital group versus the home group (-0.4% vs. -1.8%; P = 0.03). The mean variation per year in WZS was greater in the hospital group versus the home group (P < 0.01). Clinical outcome, as defined by spirometric parameters and body weight, was better after a course of treatment in hospital than after a home treatment. This benefit was maintained throughout of the study period.

Elastokine-mediated up-regulation of MT1-MMP is triggered by nitric oxide in endothelial cells.

Membrane-type I matrix metalloproteinase (MT1-MMP) has been previously reported to be up-regulated in human microvascular endothelial cell-1 line (HMEC) by elastin-derived peptides (elastokines). The aim of the present study was to identify the signaling pathways responsible for this effect. We showed that elastokines such as (VGVAPG)(3) peptide and kappa elastin induced nitric oxide (NO) production in a time-, concentration- and receptor-dependent manner as it could be abolished by lactose and a receptor-derived competitive peptide. As evidenced by the use of NO synthase inhibitors, elastokine-mediated up-regulation of MT1-MMP and pseudotube formation on Matrigel required NO production through activation of the PI(3)-kinase/Akt/NO synthase and NO/cGMP/Erk1/2 pathways. Elastokines induced both PI(3)-kinase p110gamma sub-unit, Akt and Erk1/2 activation, as shown by a transient increase in phospho-Akt and phospho-Erk1/2, reaching a maximum after 5 and 15 min incubation, respectively. Inhibitors of PI(3)-kinase and MEK1/2 suppressed elastokine-mediated MT1-MMP expression at both the mRNA and protein levels, and decreased the ability of elastokines to accelerate pseudotube formation. Besides, elastokines mediated a time- and concentration-dependent increase of cGMP, suggesting a link between NO and MT1-MMP expression. This was validated by the use of a guanylyl cyclase inhibitor, a NO donor and a cGMP analog. The guanylyl cyclase inhibitor abolished the stimulatory effect of elastokines on MT1-MMP expression. Inversely, the cGMP analog, mimicked the effect of both elastokines and NO donor in a concentration- and time-dependent manner. Overall, our results demonstrated that such elastokine properties through NO and MT1-MMP may be of importance in the context of tumour progression.

Contribution of CT-assisted navigation and microdebriders to endoscopic sinus surgery in cystic fibrosis.

OBJECTIVE: To demonstrate the interest of CT-assisted navigation and the microdebrider in rhino-sinus surgery for cystic fibrosis. METHODS: A retrospective study included 20 patients with cystic fibrosis who had undergone endoscopic sinus surgery using CT-assisted navigation and microdebrider between 1998 and 2006. RESULTS: Surgery was indicated for the following symptoms resistant to medical management: incapacitating nasal obstruction (n=18, 90%) and headache or periorbital pain (n=14, 70%). At 3 years follow-up, six patients (30%) were symptom-free, six (30%) had required re-operation, and symptoms were well controlled by medication in the other eight (40%). Mean initial bilateral surgery time was 61 min. There were no complications. CONCLUSION: The advent of microdebriders and CT-based navigation has improved endoscopic sinus surgery in cystic fibrosis. It has permitted the control of medication-resistant symptoms, especially nasal obstruction and pain. Precision is satisfactory, with reduced surgery time. No major complications have been observed. Two- or three-step surgery is possible where endoscopic anatomic landmarks have suffered alteration. The resultant control of symptoms encourages extending indications, with repeat procedures, in view of improving patients' quality of life. Further assessment on a larger series will be needed.

Plasma fatty acids and lipid hydroperoxides increase after antibiotic therapy in cystic fibrosis.

The present authors investigated whether cystic fibrosis is linked to a defect in fatty acids and assessed the impact of the main patients' characteristics on the levels of several fatty acids, mostly during respiratory exacerbation and after antibiotic therapy. Fatty acid phospholipid and cholesteryl ester levels were measured in stable-state patients and controls. No differences were found concerning either the fractions of palmitic and oleic acids or the cholesteryl esters of alpha-linolenic and arachidonic acids. However, phospholipids of alpha-linolenic and arachidonic acids, as well as cholesteryl esters and phospholipids of stearic and linoleic acids, were lower in patients than in controls, but fractions of dihomo-gamma-linolenic, docosatetraenoic, docosapentaenoic, palmitoleic and eicosatrienoic acids were higher. Fatty acid levels, oxidative stress markers, nutrients, body mass index and forced expiratory volume in one second (FEV(1)) were measured in patients before and after antibiotic courses for bronchial exacerbation. After adjustments, palmitic, stearic, alpha-linolenic, linoleic, arachidonic, palmitoleic and oleic acids generally decreased during exacerbation but almost all increased after antibiotic courses. Nearly all fractions increased along with FEV(1) and a positive relationship linked fatty acids to lipid hydroperoxides. There was no general drop in fatty acids. Patients' fatty acid profiles depended on the pulmonary function and the inflammation state.

Streptococcus pneumoniae thoracic empyema in children: rapid diagnosis by using the Binax NOW immunochromatographic membrane test in pleural fluids.

AIM: To evaluate an immunochromatographic membrane test for Streptococcus pneumoniae antigen (Binax NOW, Inverness medical France) applied to pleural fluid samples. METHODS: Binax NOW was applied to the pleural fluids of 69 children with thoracic empyema, in comparison with conventional culture and molecular techniques. RESULTS: Binax NOW was positive on all 15 pleural fluid samples that yielded S. pneumoniae in culture, on two samples that yielded S. oralis and S. salivarius in culture and on 34 culture-negative samples. Fifteen of these 34 culture-negative samples were retrospectively tested by PCR methods, and 14 were shown to contain S. pneumoniae DNA. Thus, S. pneumoniae was identified by culture in 22% of samples and by Binax NOW in 69% of samples. CONCLUSION: Binax NOW may thus be useful for rapid diagnosis of S. pneumoniae thoracic empyema.

[Rib fractures after chest physiotherapy: a report of 2 cases]. / Fractures costales au cours des bronchiolites aiguës virales: à propos de 2 cas.

The 2000 French consensus conference for acute viral bronchiolitis management underlined the fundamental role of chest physiotherapy. According to Chalumeau and al., rib fractures were found out in 1/1000 children hospitalized for bronchiolitis or pneumonia. However, such complication of chest physiotherapy is exceptional. We report 2 cases with third to sixth lateral rib fractures after chest physiotherapy in infants with bronchiolitis. Despite the rarity of these complications, clinicians must keep in mind this etiology while facing rib fractures in infants.

Macroscopic-microscopic characterization of the passive mechanical properties in rat soleus muscle.

The purpose of the study was to investigate changes in passive mechanical properties of the soleus muscle of the rat during the first year of life. These mechanical changes were quantified at a macroscopic (whole muscle) and a microscopic level (fiber) and were correlated with biochemical and morphological properties. Three passive mechanical tests (a relaxation test, a ramp stretch test and a stretch release cycle test) with different amplitudes and velocities were performed on isolated soleus muscles and fibers in rats at ages 1 (R1), 4 (R4) and 12 (R12) months. Mechanical parameters (dynamic and static forces, stresses and normalized stiffness) were recorded and measured. The morphological properties (size of fibers and muscles) for the three groups of rats were assessed by light microscopy which allowed us to observe the evolution of the fiber type (I, IIc and IIa) in the belly region and along the longitudinal axis of the muscle. In addition, biochemical analyses were performed at the level of the whole muscle in order to determine the collagen content. The results of the passive mechanical properties between the macroscopic (muscle) and microscopic (fiber) levels showed a similar evolution. Thus, an increase of the dynamic and static forces appeared between 1 and 4 months while a decrease of the passive tension occurred between 4 and 12 months. These mechanical changes were correlated to the morphological properties. In addition, the size of the three fibers type which grew with age could explain the increase of forces between 1 and 4 months. Furthermore, the biochemical analysis showed an increase of the collagen content during the same period which could also be associated with the increase of the passive forces. After 4 months, the passive tension decreased while the size of the fiber continued to increase. The biochemical analysis showed a decrease of the collagen content after 4 months, which could explain the loss of passive tension in the whole muscle. Concerning the similar loss at the fiber level, other assumptions are required such as a myofibril loss process and an increase of intermyofibrillar spaces. The originality of this present study was to compare the passive mechanical properties between two different levels of anatomical organization within the soleus muscle of the rat and to explain these mechanical changes in terms of biochemical and morphological properties.

Fibronectin type II (FnII)-like modules regulate gelatinase A activity.

Gelatinase A, a member of the matrix metalloproteinase family, contains three fibronectin type II (FnII)-like modules that are inserted within its catalytic domain. These FnII modules, defined as exosites, play an essential role in targeting the enzyme to matrix macromolecules, a process which can down-regulate membrane-type metalloproteinase-driven progelatinase A activation. The exosite/substrate-directed gelatinase inhibitors has been proposed as an alternative approach to disappointing active site-directed inhibitors, to control gelatinase A activity. In preliminary experiments, we evidenced that long-chain unsaturated fatty acids could bind preferentially to the first FnII module of gelatinase A. This interaction inhibits the activity of this enzyme towards proteins (type I gelatin and collagen) and an octapeptide substrate, with K(i) in the micromolar range. Since gelatinase A-catalyzed matrix proteolysis might display a positive or negative influence (depending on the substrate cleaved), the design of exosite-specific compounds for noncatalytic targeting of gelatinase A would necessitate an extensive degradomic analysis.