Role of gelatinase B and elastase in human polymorphonuclear neutrophil migration across basement membrane

Polymorphonuclear neutrophil (PMN) migration across basement membrane is thought to be dependent on the degradation of membrane constituents. PMN gelatinase B, a metalloproteinase able to degrade type IV collagen, may be involved in this phenomenon. PMN gelatinase B is released in the extracellular medium as a latent proform and then activated, mainly by PMN elastase. We investigated the role of gelatinase B in PMN migration across a Matrigel basement membrane matrix coated onto a filter, in a Boyden chamber. The effects of gelatinase and elastase inhibitors on PMN migration in this system were tested. Chemokinesis of PMN was tested in the same Boyden chamber across a filter free of basement membrane. The agarose method was used to test the same inhibitors for effects on PMN chemotaxis. In both systems, FMLP 10(-7)M was used as a chemoattractant. Addition of 10(-8)M TIMP-1 (the preferential gelatinase B inhibitor) inhibited trans-basement membrane PMN migration by 52 +/- 6% (P<0.05), without affecting PMN chemokinesis, chemotaxis, or degranulation. Also, (Ala)(2) Pro Val chloromethyl ketone (AAPVCK) 100 micron, a specific elastase inhibitor, inhibited trans-basement membrane PMN migration by 51 +/- 8% (P<0.05), without affecting PMN chemokinesis, chemotaxis, or degranulation. The AAPVCK-TIMP combination led to a decrease in migration across Matrigel basement membrane (46 +/- 2%, P,0.05)similar to that seen with TIMP alone. AAPVCK was responsible for inhibition of gelatinase B activation, leading to a decrease in activated gelatinase from 14% to 2% of total gelatinase release (P<0.05). All these results strongly suggest that gelatinase B is a major factor of PMN migration across basement membrane and that elastase may contribute to this process by activating pro-gelatinase B.

A 3.6 V lithium-based fluorosulphate insertion positive electrode for lithium-ion batteries

Li-ion batteries have contributed to the commercial success of portable electronics, and are now in a position to influence higher-volume applications such as plug-in hybrid electric vehicles. Most commercial Li-ion batteries use positive electrodes based on lithium cobalt oxides. Despite showing a lower voltage than cobalt-based systems (3.45 V versus 4 V) and a lower energy density, LiFePO(4) has emerged as a promising contender owing to the cost sensitivity of higher-volume markets. LiFePO(4) also shows intrinsically low ionic and electronic transport, necessitating nanosizing and/or carbon coating. Clearly, there is a need for inexpensive materials with higher energy densities. Although this could in principle be achieved by introducing fluorine and by replacing phosphate groups with more electron-withdrawing sulphate groups, this avenue has remained unexplored. Herein, we synthesize and show promising electrode performance for LiFeSO(4)F. This material shows a slightly higher voltage (3.6 V versus Li) than LiFePO(4) and suppresses the need for nanosizing or carbon coating while sharing the same cost advantage. This work not only provides a positive-electrode contender to rival LiFePO(4), but also suggests that broad classes of fluoro-oxyanion materials could be discovered.

Allergy to betalactam antibiotics in children: results of a 20-year study based on clinical history, skin and challenge tests

Studies based on skin and challenge tests have shown that 12-60% of children with suspected betalactam hypersensitivity were allergic to betalactams. Responses in skin and challenge tests were studied in 1865 children with suspected betalactam allergy (i) to confirm or rule out the suspected diagnosis; (ii) to evaluate diagnostic value of immediate and non-immediate responses in skin and challenge tests; (iii) to determine frequency of betalactam allergy in those children, and (iv) to determine potential risk factors for betalactam allergy. The work-up was completed in 1431 children, of whom 227 (15.9%) were diagnosed allergic to betalactams. Betalactam hypersensitivity was diagnosed in 50 of the 162 (30.9%) children reporting immediate reactions and in 177 of the 1087 (16.7%) children reporting non-immediate reactions (p<0.001). The likelihood of betalactam hypersensitivity was also significantly higher in children reporting anaphylaxis, serum sickness-like reactions, and (potentially) severe skin reactions such as acute generalized exanthematic pustulosis, Stevens-Johnson syndrome, and drug reaction with systemic symptoms than in other children (p<0.001). Skin tests diagnosed 86% of immediate and 31.6% of non-immediate sensitizations. Cross-reactivity and/or cosensitization among betalactams was diagnosed in 76% and 14.7% of the children with immediate and non-immediate hypersensitivity, respectively. The number of children diagnosed allergic to betalactams decreased with time between the reaction and the work-up, probably because the majority of children with severe and worrying reactions were referred for allergological work-up more promptly than the other children. Sex, age, and atopy were not risk factors for betalactam hypersensitivity. In conclusion, we confirm in numerous children that (i) only a few children with suspected betalactam hypersensitivity are allergic to betalactams; (ii) the likelihood of betalactam allergy increases with earliness and/or severity of the reactions; (iii) although non-immediate-reading skin tests (intradermal and patch tests) may diagnose non-immediate sensitizations in children with non-immediate reactions to betalactams (maculopapular rashes and potentially severe skin reactions especially), the diagnostic value of non-immediate-reading skin tests is far lower than the diagnostic value of immediate-reading skin tests, most non-immediate sensitizations to betalactams being diagnosed by means of challenge tests; (iv) cross-reactivity and/or cosensitizations among betalactams are much more frequent in children reporting immediate and/or anaphylactic reactions than in the other children; (v) age, sex and personal atopy are not significant risk factors for betalactam hypersensitivity; and (vi) the number of children with diagnosed allergy to betalactams (of the immediate-type hypersensitivity especially) decreases with time between the reaction and allergological work-up. Finally, based on our experience, we also propose a practical diagnostic approach in children with suspected betalactam hypersensitivity.

Mild asthma: an expert review on epidemiology, clinical characteristics and treatment recommendations

This review is the synthesis of a working group on mild asthma. Mild asthma includes intermittent and persistent mild asthma according to the Global Initiative for Asthma (GINA) classification, and affects between 50% and 75% of asthmatic patients. Mild asthma is more frequent, more symptomatic, and less well controlled in children than in adults. Cohort studies from childhood to adulthood show that asthma severity usually remains stable over time. Nevertheless, mild asthma can lead to severe exacerbations, with a frequency ranging from 0.12 to 0.77 per patient-year. Severe exacerbations in mild asthma represent 30-40% of asthma exacerbations requiring emergency consultation. In mild asthma, inflammation and structural remodelling are constant, of varying intensity, but nonspecific. Therapy with inhaled corticosteroids (ICS) decreases bronchial inflammation, but has only a slight effect on structural remodelling, and, when stopped, inflammation immediately recurs. Permanent low-dose ICS therapy is the reference treatment for persistent mild asthma. Effectiveness is to be reassessed at 3 months, and if it is insufficient the patient is no longer considered mildly asthmatic, and treatment has to be stepped up. As mild asthma is the most frequent form of the disease, diagnosis and management require physicians' particular attention.

Efficacy of nebulized budesonide in treatment of severe infantile asthma: a double-blind study

BACKGROUND AND OBJECTIVE

Treatments with inhaled corticosteroids yielded conflicting results in infants with severe asthma. The purpose of this study was to assess the efficacy of nebulized budesonide on the control of asthma in this age group.

METHODS

In a double-blind, placebo-controlled study, 40 infants with severe asthma received either nebulized budesonide (1 mg) or placebo twice daily for 12 weeks, followed by a follow-up period of up to 12 weeks. A jet nebulizer driven by an air compressor was used to administer budesonide and placebo.

RESULTS

Fewer patients in the budesonide group had an exacerbation during the treatment period (40%) compared with the placebo group (83%, p < 0.01). The duration of oral steroid therapy was shorter in the budesonide group than in the placebo group (median number of days of exacerbation as a proportion of the total treatment time, 0% vs 14.5%; p < 0.05). The incidence of daytime (p < 0.05) and nighttime wheezing (p < 0.01) was lower in the budesonide group than in the placebo group during the treatment period. The proportion of patients without an exacerbation of asthma during the entire 24 weeks was 28% for those patients who had received budesonide and 0% for those patients who had received placebo. Asthma improved in more patients in the budesonide group (17 and 19, 89%) than in the placebo group (7 of 16, 44%; p < 0.005). These results should improve and modify the treatment of infants with severe asthma.

CONCLUSION

Nebulized budesonide (1 mg twice daily) is a well-tolerated and efficient treatment for severe infantile asthma.

Congenital diaphragmatic hernia

Infants with congenital diaphragmatic hernia (CDH) have significant mortality and long-term morbidity. Only 60-70% survive and usually those in high-volume centres. The current Task Force, therefore, has convened experts to evaluate the current literature and make recommendations on both the antenatal and post-natal management of CDH. The incidence of CDH varies from 1.7 to 5.7 per 10,000 live-born infants depending on the study population. Antenatal ultrasound scanning is routine and increasingly complemented by the use of magnetic resonance imaging. For isolated CDH, antenatal interventions should be considered, but the techniques need vigorous evaluation. After birth, management protocols are often used and have improved outcome in nonrandomised studies, but immediate intubation at birth and gentle ventilation are important. Pulmonary hypertension is common and its optimal management is crucial as its severity predicts the outcome. Usually, surgery is delayed to allow optimal medical stabilisation. The role of minimal invasive post-natal surgery remains to be further defined. There are differences in opinion about whether extracorporeal membrane oxygenation improves outcome. Survivors of CDH can have a high incidence of comorbidities; thus, multidisciplinary follow-up is recommended. Multicentre international trials are necessary to optimise the antenatal and post-natal management of CDH patients.

Use of the forced oscillation technique to assess airway obstruction and reversibility in children

The forced oscillation technique (FOT) is particularly attractive in a pediatric setting as it requires only passive cooperation from the child. We assessed the sensitivity and specificity of this method for detecting airway obstruction and its reversibility in 313 children (3 to 16 yr of age) with asthma or chronic nocturnal cough. Baseline and post-bronchodilator (n = 251) resistance were measured (R(0)) with the FOT. Baseline R(0) was normalized for height and weight [R(0)(SD)]. In children able to perform forced expiratory maneuvers (n = 181), R(0)(SD) was independently correlated with FEV(1) (p < 0.02) and maximal expiratory flow at 50% (MEF(50)) (p < 0.004). The optimal R(0)(SD) cutoff value given by receiver operating characteristic (ROC) curves to discriminate between children with baseline FEV(1) < 80% or >/= 80% of predicted values yielded 84% sensitivity and 73% specificity. Post-bronchodilator changes in R(0)(SD) [DeltaR(0)(SD)] were mostly correlated to changes in MEF(50). The optimal DeltaR(0)(SD) cutoff value to discriminate between children with the presence or absence of significant reversibility in FEV(1) yielded 69% sensitivity and 78% specificity. In children unable to perform forced expiratory maneuvers (n = 132), this DeltaR(0)(SD) cutoff clearly identified a subgroup of young children with high R(0) values at baseline, that returned to normal after bronchodilation. We conclude that FOT measurements allow reliable evaluation of bronchial obstruction and its reversibility in asthmatic children over 3 yr old.

Imbalance between 95 kDa type IV collagenase and tissue inhibitor of metalloproteinases in sputum of patients with cystic fibrosis

A growing body of evidence suggests that neutrophil-derived proteinases play a major role in lung tissue damage in cystic fibrosis (CF). Most previous studies have focused on serine proteinases such as neutrophil elastase, providing no information on the extent to which metalloproteinases participate in proteolytic processes in CF. To address this issue, we evaluated the contribution of one of the major neutrophil metalloproteinases, i.e., 95 kDa gelatinase (type IV collagenase), to the total gelatinolytic activity measured in sputum specimens from 27 patients with CF. Compared with asthmatic children (n = 9), CF patients had a 6.7 times greater level of total gelatinase activity in sputum revealed by zymography. The 95 kDa gelatinase was increased 3.7-fold in the CF subjects (2,441 +/- 411 [SEM] arbitrary units [AU] x 10(6) per ml of sputum versus 665 +/- 201 in asthmatics) and the 88-kDa active form 23.2-fold (2,272 +/- 372 AU x 10(6) per ml of sputum versus 98 +/- 43, respectively). Using radiolabeled 3H-gelatin as the substrate, we demonstrated uninhibited gelatinolytic activity in all CF patients; this activity was significantly correlated to disease severity as assessed by pulmonary function tests. Western blotting using anti-tissue inhibitor of metalloproteinase (anti-TIMP) and anti-95/88-kDa gelatinase antibodies demonstrated a more than 10-fold excess of 95/88 kDa gelatinase over TIMP. Bacterial proteinases from Pseudomonas aeruginosa were shown to contribute little to the gelatinolytic activity measured in sputum supernatants from patients with CF, although culture supernatants from various P. aeruginosa strains expressed gelatinolytic activity in vitro. Finally, lung damage, as assessed by increased type IV collagen degradation products in sputum, was significantly correlated to concentrations of active 88 kDa gelatinase. These data argue for a significant role of 95/88 kDa gelatinase in airway damage in CF.

Computed tomography with normal chest radiograph in tuberculous infection

Children with primary tuberculosis infection without disease must be identified and treated preventively to avoid an increase in the incidence of tuberculosis in children. However, the recognition of infected cases without disease is often difficult. In particular, minimal active disease may be present in many cases but unrecognised on chest radiography. Computed tomography was therefore performed in 15 children with tuberculous infection and a normal chest radiograph to measure the size of their mediastinal lymph nodes. Ten control children without tuberculosis were also evaluated. When compared with controls it was found that nine of 15 (60%) infected children had enlarged lymph nodes. Adenopathies were more frequent in infected children less than 4 years old than in those over 8 years old. The demonstration of unrecognised active disease in many infected children raises the question of the adequate treatment for these children. It is proposed that a two drug regimen would be more appropriate than isoniazid alone in these cases.

Neutrophil-derived long-lived oxidants in cystic fibrosis sputum

We evaluated long-lived oxidant potential in the sputum of patients with cystic fibrosis (CF) by quantitating the methionine-inhibitable, long-lived oxidant fraction of sputum, referred to as the chloramines. Taurine, the preferred amino acid substrate for chloramine formation, and myeloperoxidase (MPO), the chlorinated oxidant-generating enzyme, were also quantitated. As compared with the sputum of asthmatic subjects, the sputum of CF patients contained high concentrations of chloramines along with high levels of taurine and active MPO. A negative correlation between chloramine and taurine was found in the sputum of CF patients. No correlation was found between the density of Pseudomonas aeruginosa and the level of chloramines, taurine, or MPO. In contrast, respiratory parameters (%FEV or %FVC) and a nutritional index correlated positively with chloramine levels, whereas negative correlations were observed with taurine and MPO. In addition, the effect of antibiotic therapy, which significantly increased chloramine and decreased taurine levels, supported a beneficial effect of chloramines on overall clinical status. Our findings support a dual role of long-lived oxidants at the site of airway inflammation in CF, one component of which is their ability to mediate oxidative stress and the other a beneficial effect that may be partly explained by their inhibitory effect on antiprotease defense systems.

Use of polymerase chain reaction for improved diagnosis of tuberculosis in children

OBJECTIVE

To study the value of a rapid diagnostic method based on the amplification by polymerase chain reaction (PCR) of a fragment of the IS6110 insertion element for the detection of Mycobacterium tuberculosis in children.

DESIGN

We tested 199 specimens obtained from 68 children referred for evaluation of suspected tuberculosis.

RESULTS

In 83.3% of children with active disease and 38.9% with tuberculous infection but no evidence of disease, at least one positive PCR result was observed. No child without tuberculosis had positive PCR results (100% specificity). The sensitivity of the PCR was increased by testing of multiple samples from the same child and use of Chelex particles (Bio-Rad Laboratories, Ivry, France) rather than guanidine isothiocyanate-silica particles for DNA extraction. Bronchoalveolar lavage samples were no more useful than gastric aspirates.

CONCLUSIONS

If appropriate laboratory methods are used, DNA amplification is a reliable method for the early diagnosis of tuberculosis in children and appears to be very helpful in clinical pediatric practice when the diagnosis of active tuberculosis is difficult or needs to be rapidly confirmed.

Sensitization to inhalant allergens in wheezing infants is predictive of the development of infantile asthma

Early recognition of infantile asthma in wheezing infants is a major problem for physicians. We investigated whether detection of early sensitization to inhalant allergens would be useful to identify those wheezing infants who are likely to develop asthma. A total of 67 infants (aged 1-25 months) hospitalized for a wheezing episode were initially tested for reactivity to inhalant allergens by both skin prick test and in vitro measurement of specific IgE antibodies (Phadiatop). Thirty-seven of the infants were already considered to have infantile asthma, and 30 presented only their first or second wheezing episode when included in the study. All infants were followed for a mean period of 18 months. Seventeen (25%) infants, including seven infants initially not asthmatic, had positive prick test to Dermatophagoides pteronyssinus or to cat fur. All of these children were diagnosed as suffering from infantile asthma at the end of the follow-up. Thus, skin test positivity to inhalant allergens was significantly associated with the diagnosis of infantile asthma (P < 0.05) and could be considered to be predictive of the development of infantile asthma (P < 0.03). In contrast, Phadiatop was less sensitive than skin prick tests, and only five children had positive in vitro test results, suggesting that specific IgE may primarily bind to tissue mast cells before being detectable in serum. We concluded that sensitization to inhalant allergens may distinguish wheezing infants who develop asthma from those who do not, and that skin testing may assist the early diagnosis of asthma in wheezing infants.

Various strategies to tune the ionic/electronic properties of electrode materials

This Perspective highlights, through several snapshot examples, the importance of electrochemically-driven redox reactions in tuning the electronic/ionic as well as magnetic properties of 3d-metal-based inorganic compounds through a careful control of the metal oxidation state. Although such redox reactions usually imply the electron-ionic duality, they can be extended to insulating compounds (LiFePO(4)) or semiconductors (CoO) as long as we can combine electrochemistry at the nanoscale to reduce diffusion and migration limitations, and provide the compounds with electrons through metallic coating techniques. A thorough investigation of the composition-structure-property relationships of the Li(x)CoO(2) system, through the assembly of LiCoO(2)/Li electrochemical cells has led to the identification of the CoO(2) phase, whose property and stability are discussed in terms of cationic-anionic redox competition, thus bearing some similarity with the high T(c) cuprate superconductors. Such a d-sp redox competition could have structural and electronic consequences. Encouraged by the recently reported superconductivity in Na(x)CoO(2);yH(2)O phase, the room temperature Li(x)CuO(2) phase diagram was reinvestigated through Li-driven electrochemical reactions. A solid solution domain was unravelled but superconductivity was not evident. With Cu-based materials such as Cu(2.33)V(4)O(11), we have shown the feasibility of a new reversible Li electrochemically-driven copper extrusion/insertion process, owing to the enhanced copper diffusion within the structure.

Update on the roles of distal airways in asthma

The present review is the summary of an expert workshop that took place in Vence (France) in 2007 on the role of distal airways in asthma. The evidence showing inflammation and remodelling in distal airways, and their possible involvement in asthma control and natural history, was reviewed. The usefulness and limitations of various techniques used for assessing distal airways were also evaluated, including pulmonary function tests and imaging. Finally, the available data studying the benefit of treatment better targeting distal airways in asthma was examined. It was concluded that both proximal and distal airways were involved in asthma and that distal airways were the major determinant of airflow obstruction. Inflammation in distal airways appeared more intense in severe and uncontrolled asthma. Distal airways were poorly attained by conventional aerosol of asthma medications owing to their granulometry, being composed of 3-5&emsp14;μm particles. Both proximal and distal airways might be targeted either by delivering medications systemically or by aerosol of extra-fine particles. Extra-fine aerosols of long-acting β-agonists, inhaled corticosteroids or inhaled corticosteroid/long-acting β-agonist combinations have been shown in short-term studies to be not inferior to non-extra-fine aerosols of comparators. However, available studies have not yet demonstrated that extra-fine inhaled medications offer increased benefit compared with usual aerosols in asthmatic patients.

Comparison of the forced oscillation technique and the interrupter technique for assessing airway obstruction and its reversibility in children

The forced oscillation technique (FOT) and interrupter technique are particularly attractive for pediatric use as they require only passive cooperation from the patient. We compared the sensitivity and specificity of these methods for detecting airway obstruction and its reversibility in 118 children (3-16 yr) with asthma or chronic nocturnal cough. FOT (R(0) and R(16)) and interruption (Rint) parameters were measured at baseline and after bronchodilator inhalation (n = 94). Rint was significantly lower than R(0), especially in children with high baseline values. Baseline parameters were normalized for height and weight [R(SD)]. In children able to perform forced expiratory maneuvers (n = 93), the best discrimination between those with baseline FEV(1) < 80% or > or = 80% of predicted values was obtained with R(0)(SD). At a specificity of 80%, R(0)(SD) yielded 66% sensitivity, whereas Rint(SD) yielded only 33% sensitivity. Similarly, postbronchodilator changes in R(0)(SD) [DeltaR(0)(SD)] yielded the best discrimination between children with and without significant reversibility in FEV(1). At a specificity of 80%, DeltaR(0)(SD) yielded 67% sensitivity and DeltaRint(SD) yielded 58% sensitivity. In children unable to perform forced expiratory maneuvers (n = 25), FOT, contrary to the interrupter technique, clearly identified a subgroup of young children with high resistance values at baseline, which returned to normal after bronchodilation. We conclude that, in asthmatic children over 3 yr old, FOT measurements provide a more reliable evaluation of bronchial obstruction and its reversibility compared with the interrupter technique, especially in young children with high baseline values.

Gelatinases in epithelial lining fluid of patients with adult respiratory distress syndrome

Gelatinases A and B are matrix metalloproteinases secreted as inactive pro forms and are capable of degrading basement membrane components after activation in the extracellular environment. To determine whether the presence of gelatinases A (noninflammatory cells) and B (inflammatory cells) in epithelial lining fluid (ELF) is associated with the adult respiratory distress syndrome (ARDS), we studied 28 patients divided into four groups based on the presence of ARDS and/or multiple organ failure (MOF). Gelatinase activities were quantified in ELF using zymography. ARDS patients had larger ELF volumes than non-ARDS patients: 9.2 +/- 8.5 ml/100 ml recovered lavage fluid (n = 18) vs. 1.9 +/- 1.7 ml/100 ml (n = 11), respectively (P < 0.001). The presence of activated gelatinase A in ELF was a sensitive (16 out of 18 ARDS patients, 89%) and specific (0 out of 11 non-ARDS patients with or without MOF) marker for ARDS. Activated gelatinase (A + B) activities per microliter ELF were correlated with albumin concentrations in ELF (P < 0.01), and activated gelatinase activities in ELF were correlated with the volume of ELF (P < 0.0005). This could suggest an involvement of these gelatinases in alveolar-capillary permeability increase.

Relationship between bronchial responsiveness and clinical evolution in infants who wheeze: a four-year prospective study

Recurrent illness involving wheezing during the first years of life is transient in most children. The role of bronchial hyperresponsiveness as a factor influencing the persistence of wheezing from infancy to school age remains unknown. In a prospective study we investigated whether infants who wheezed and subsequently developed persistent asthma differed from infants who wheezed and later became asymptomatic either in the initial degree of bronchial hyperresponsiveness or in the persistence of bronchial hyperresponsiveness with age. One hundred and twenty-nine infants with three or more wheezing episodes before 2 yr of age were followed during 4 yr with a clinical evaluation and a methacholine challenge performed every 6 mo until the child was 4 yr old and once per year thereafter. The clinical score significantly improved with time in most children. The proportion of children with persistent wheezing after 2 and 4 yr of follow-up was only 31% and 20%, respectively. Persistent wheezers had significantly lower VmaxFRC values at initial evaluation and higher SRaw values at the end of follow-up than infants who became asymptomatic. We used transcutaneous oxygen tension (PtcO(2)) to measure the response to methacholine. No significant difference in PD(15) PtcO(2) between groups with subsequently different clinical progression was observed at initial evaluation. Bronchial hyperresponsiveness persisted 4 yr later in all children but children with persistent wheezing showed significantly lower PD(15) PtcO(2) values than children who became asymptomatic, as early as 30 mo of age. However, an acceptable early PD(15) PtcO(2) cut-off point predictive for subsequent clinical progression could not be identified. The level of bronchial hyperresponsiveness in infants who wheezed was not predictive of the persistence of asthma 4 yr later.

Ultrathin flexible bronchoscopy in neonatal intensive care units

Thirty seven flexible bronchoscopies were performed in 33 infants in a neonatal intensive care unit, using a 2.2 mm flexible ultrathin bronchoscope. Twenty eight procedures were performed via an endotracheal tube or tracheostomy and nine in spontaneously breathing infants. Indications for endoscopy included persistent atelectasis and/or emphysema (n = 21), unexplained acute respiratory distress (n = 10), stridor (n = 3), assessment of congenital abnormalities of the tracheobronchial tree (n = 2), and follow up of an endobronchial granuloma during the course of corticosteroid treatment (n = 1). Abnormal airway dynamics and/or abnormal structure were seen in 23 of 37 cases. In 54% of the procedures, the results of bronchoscopy had a direct effect on further management. The procedure was well tolerated and completed in less than two minutes. Our results suggest that the ultrathin flexible bronchoscope improves airway exploration and the understanding of respiratory disorders during the first months of life, particularly in ventilated infants.

Value of ELISA using antigen 60 for the diagnosis of tuberculosis in children

We evaluated the possible value of enzyme-linked immunosorbent assay (ELISA) using antigen 60 (A60) for improved diagnosis of tuberculosis in children. Results obtained in 31 children with active tuberculosis and in 16 patients with tuberculous infection without disease were compared with the results of 198 control subjects with no mycobacterial disease. In control children, anti-A60 IgG increased with age and the optical density (OD) in ELISA assays rose from .079 +/- .053 (OD +/- SD) in children younger than 5 years old to 0.146 +/- 0.082 OD in children older than 5 years. In control subjects younger than 2 years old, IgG OD values were significantly higher in BCG-vaccinated children than in nonvaccinated children. At a chosen specificity of 98 percent, a positive serodiagnosis was observed in 68 percent of children with clinically active tuberculosis. In these children with active disease, smears were positive in only 26 percent of cases and mycobacterial cultures yielded the organism in 45 percent of cases. None of the infected children without disease had high IgG OD values. IgM measurements were also evaluated. Mean values from control and diseased children overlapped, leading to a low sensitivity (19 percent) in children with clinically tuberculosis active. We conclude that anti-A60 IgG measurement is a rapid and low-cost technique that enhances the diagnosis of clinically active tuberculosis in children and may distinguish recent infection without disease from infection with disease.

[Streptococcus pneumoniae serotypes involved in children with pleural empyemas in France]

It has been suggested that the incidence of childhood empyema have increased during the last years in France without clear explanation. Streptococcus pneumoniae is responsible for the vast majority of bacteriological documented cases. Potential prevention of pleural empyemas by the heptavalent pneumococcal conjugate vaccine is dependent on adequation between specific pneumococcal serogroups present in vaccine and those responsible for empyemas.

MATERIAL AND METHODS

We retrospectively collected cases of pleural empyemas registered at the National Reference Center for pneumococci (December 2002 to February 2004). Thirty children, aged 4.1+/-3.3 (SD) years, were included.

RESULTS

Ten specific serogroups were identified: 1, 3, 5, 6B, 7F, 9V, 14, 18C, 19A, and 23F. Serogroups 19A and 1 were the 2 dominant serogroups and represented 50% of cases. All children infected with serotype 19A were younger than 5 years, whereas serotype 1 was identified in 80% of empyemas in children older than 5 years. Among the 30 patients enrolled, 20 (69%) were infected with serotypes not included in the conjugate vaccine.

CONCLUSION

These results thus limit the potential impact of the heptavalent pneumococcal conjugate vaccine on the frequency of pleural empyemas in children.

Late and ultra late onset Streptococcus B meningitis: clinical and bacteriological data over 6 years in France

BACKGROUND

Group B Streptococcus (GBS) is one of the leading causes of sepsis and meningitis in newborn. The objective of this study was to describe the characteristics of GBS meningitis in children aged between 7 and 89 days (late onset disease - LOD group) and to compare them with children aged more than 3 months (ultra late onset disease - ULOD group).

METHODS

Clinical and biological data were gathered by ACTIV/GPIP (a nationwide active surveillance network). The study population included 242 children hospitalized between 2001 and 2006 for GBS meningitis (220 in the LOD group and 22 in the ULOD group).

RESULTS

Univariate analysis revealed that gestational age (GA) was significantly lower in the ULOD group as compared with the LOD group (respectively 35.6 weeks vs. 37.9 weeks, p = 0.002). Prevalence of early preterm birth (before the 32nd week GA) was significantly higher in the ULOD group than in the LOD group (32% vs. 7%, p = 0.002). No significant difference was found between the two groups for biological characteristics of lumbar puncture, GBS serotypes, complications and survival rate.

CONCLUSION

These data suggest that LOD and ULOD would be the same clinical and bacteriological entity, except for prematurity, which seems significantly associated with ULOD.

Matrix metalloproteinase and elastase activities in LPS-induced acute lung injury in guinea pigs

Matrix metalloproteinases (MMPs) and elastase are proteolytic enzymes specifically directed against extracellular matrix (ECM) components. They are secreted by inflammatory cells and may consequently contribute to the lesions of the ECM observed during acute pulmonary edema. We therefore evaluated the MMP and elastase activities, which are secreted by cultured alveolar macrophages (AMACs) and polymorphonuclear neutrophils (PMNs) and present in the bronchoalveolar lavage (BAL) fluid in a guinea pig model of acute lung injury induced by intratracheal instillation of lipopolysaccharide (LPS). The control group was given 0.9% NaCl. 24 h after instillation, a BAL was performed, the BAL fluid was separated from the cells by centrifugation, and AMACs and PMNs were separately cultured for 24 h. In BAL fluid from LPS-treated guinea pigs, we found 1) an increase in free gelatinase activity, tested on [3H]gelatin (0.7 +/- 0.2 micrograms.200 microliters BAL fluid-1.48 h-1 vs. 0.2 +/- 0.1 in controls, P < 0.05), and 2) increased total gelatinase activities, as assessed by zymography. The molecular masses of the major gelatinase species found in BAL fluid by zymography were 92 and 68 kDa. The 92-kDa gelatinase was secreted by both AMACs and PMNs, as demonstrated by zymography of their respective culture media. When tested on [3H]elastin, the elastase activity of BAL fluid of LPS-treated animals exhibited no increase, but when tested on a synthetic peptidic substrate [N-succinyl-(L-alanine)3-p-nitro anilide (SLAPN)], increased elastase-like activity was observed (from 17 +/- 4 nmol of SLAPN.200 microliters BAL fluid-1.24 h-1 in control group to 34 +/- 8 in LPS group, P < 0.05). This increase was attributable to the activity of a metalloendopeptidase that was inhibited by the metal chelator EDTA but not by the specific tissue inhibitor of MMPs.

Tuberculosis contact investigation and short-course preventive therapy among young children in Africa

SETTING: The largest cities in Benin, Burkina Faso, Cameroon and Central African Republic.OBJECTIVE: To demonstrate the feasibility and document the effectiveness of household contact investigation and preventive therapy in resource-limited settings.DESIGN: Children under 5 years living at home with adults with bacteriologically confirmed pulmonary tuberculosis (TB) were screened using questionnaire, clinical examination, tuberculin skin test and chest X-ray. Children free of active TB were offered preventive treatment with a 3-month rifampicin-isoniazid (3RH) or 6-month isoniazid (6H) regimen in Benin. Children were followed-up monthly during treatment, then quarterly over 1 year. Costs of transportation, phone contacts and chest X-rays were covered.RESULTS: A total of 1965 children were enrolled, of whom 56 (2.8%) had prevalent TB at inclusion. Among the 1909 children free of TB, 1745 (91%) started preventive therapy, 1642 (94%) of whom completed treatment. Mild adverse reactions, mostly gastrointestinal, were reported in 2% of children. One case of incident TB, possibly due to a late TB infection, was reported after completing the 3RH regimen.CONCLUSION: Contact investigation and preventive therapy were successfully implemented in these resource-limited urban settings in programmatic conditions with few additional resources. The 3RH regimen is a valuable alternative to 6H for preventing TB.

Ability of new lung function tests to assess methacholine-induced airway obstruction in infants

We assessed the ability of innovative lung function tests to detect bronchial obstruction induced by methacholine bronchial challenge. Fifty-five recurrently wheezy infants (mean age 16 +/- 5.2 months) free of respiratory symptoms underwent baseline lung function tests. Forty-two completed the methacholine challenge. Maximal flow at functional residual capacity (VmaxFRC) was obtained using the squeeze technique; compliance and resistance of the respiratory system (Crs, Rrs) was measured with the passive expiatory flow volume technique; tidal volume breathing patterns were analyzed from recordings of respiratory rate (RR), tidal volume (VT), and inspiratory time divided by total cycle of duration (Ti/Ttot). Expiratory tidal flow volume (V/VT) curves were described with multiple indices such as the ratio of expiratory time necessary to reach peak tidal expiratory flow (Fpet) to expiratory time (Tme/Te). Transcutaneous oxygen tension (PtCO2) was measured as an indicator of response to methacholine challenge. Of 42 infants 41 responded to methacholine by a change > or = 2 standard deviations from baseline values. The mean SD unit changes were 9.8 in PtCO2, 3.7 for VmaxFRC, 2.8 for Crs, 2.09 for Rrs, 3.1 for RR, 1.6 for Ti/Ttot, 2.2 for Tme/Te 3.9 for PFVt. We conclude that these noninvasive lung function tests, especially VmaxFRC and Fpet, can be used to detect minor or moderate airway obstruction. Further studies are needed to determine the value of the tests in assessing bronchial disease and effects of its treatment.