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Biomedical subjects

J de Blic

Publications and source records attributed to J de Blic.

At least 91 records · Page 5Linked to original sources

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.

Adolescent↗

Enhanced arachidonic acid metabolism in alveolar macrophages from wheezy infants. Modulation by dexamethasone.

To test the hypothesis that alveolar macrophages (AM) from wheezy infants release increased amounts of eicosanoids, as do AM from adults with asthma, we compared eicosanoid release by unstimulated- and ionophore-A23187-stimulated AM from 13 wheezy and six nonwheezy infants and analyzed its regulation by dexamethasone in vitro. Alveolar macrophages from wheezy infants released greater amounts of thromboxane A2 (TxA2) and leukotriene B4 (LTB4) under resting conditions and of TxA2 upon stimulation than did those from control subjects. Dexamethasone induced a dose-dependent inhibition of the spontaneous and A23187-stimulated release of TxA2, but not of the A23187-stimulated release of lipoxygenase products. The inhibition of TxA2 formation was maintained when free arachidonic acid was added during A23187 stimulation, demonstrating that dexamethasone acted mainly at a postphospholipase A2 site. AM exposed to acetylsalicylate and then incubated overnight exhibited de novo cyclooxygenase synthesis, suggesting the presence of the inducible cyclooxygenase as a target for inhibition by dexamethasone. In conclusion, our findings suggest that AM from wheezy infants are activated in vivo to release eicosanoids, as are AM from asthmatic adults, and they support the therapeutic indications of glucocorticoids in severe recurrent wheezing of infancy.

Adult↗

Nonspecific refractoriness to adenylyl cyclase stimulation in alveolar macrophages from infants with recurrent bronchiolitis.

Epidemiologic studies suggest an association between recurrent bronchiolitis in children younger than 3 years of age and diagnosis of asthma later in life. Bronchoalveolar lavages from 20 infants with recurrent wheezing and 18 nonwheezy control subjects were analyzed to determine whether alveolar macrophages of wheezy infants present abnormalities similar to those described in adults with asthma. Alveolar macrophages from both groups responded in vitro, in a concentration-dependent manner, to prostaglandin E2, salbutamol, and forskolin, drugs that increase cyclic adenosine monophosphate levels. However, alveolar macrophages from infants with recurrent wheezing accumulated less cyclic adenosine monophosphate than those from control subjects in response to all three stimulations. These results are in agreement with the reduced cyclic adenosine monophosphate response to different agonists demonstrated in leukocytes from patients with asthma, and suggest that this refractoriness could be one of the precipitating events in the development of asthma observed in a large proportion of infants who have had bronchiolitis.

Adenylyl Cyclases↗

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.

Aging↗

Bronchopulmonary dysplasia: value of CT in identifying pulmonary sequelae.

OBJECTIVE: Pulmonary dysfunction is common in children who survive bronchopulmonary dysplasia. Chest radiographs are not satisfactory for the identification of the sequelae of bronchopulmonary dysplasia because, although they often show abnormalities, the abnormalities are usually minor and sometimes absent. We therefore assessed the value of CT for identifying the sequelae of bronchopulmonary dysplasia. MATERIALS AND METHODS: Twenty-three children (mean age, 4 years) who had survived neonatal bronchopulmonary dysplasia and had signs of chronic pulmonary dysfunction (recurrent episodes of coughing, wheezing, dyspnea, pneumonia, respiratory insufficiency) were examined with chest radiographs and high-resolution CT scans of the chest. Two reviewers qualitatively analyzed the chest radiographic and CT findings by describing the most consistently found lesions and their frequencies. RESULTS: The chest radiographs showed hyperexpansion in 17, hyperlucent areas in 11, and linear opacities in 10 of the 23 children. Pleural thickening was not observed, and four children had normal findings on chest radiographs. All 23 CT scans showed abnormalities, including multifocal areas of hyperaeration, well-defined linear opacities, and triangular subpleural opacities with an external base and an internal apex. In 20 of 23 children, all three abnormalities were present. For the three other children, two of these three abnormalities were found. No bronchiectasis was observed in any of the cases. CONCLUSION: Lesions in survivors of bronchopulmonary dysplasia with chronic pulmonary dysfunction are visualized better on CT scans than on chest radiographs. Importantly, CT findings of multifocal areas of hyperaeration, numerous linear opacities facing triangular subpleural opacities visible on several consecutive sections, and no bronchiectasis should suggest the presence of sequelae of bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia↗

[Value of ipratropium bromide in asthma crisis in children].

Ipratropium bromide is a synthetic derivative of atropine with little absorption when used in inhalation, and therefore little secondary effects. The authors review its pharmacological properties and therapeutic efficacy in the treatment of asthma in children. Combined nebulized inhalation of ipratropium bromide and beta 2 sympathomimetic results in a more efficient and more sustained bronchodilatation than beta 2 sympathicomimetic alone in the treatment of acute asthma in children. Ipratropium bromide should be usefully introduced in the therapeutic scheme of acute asthma in children. Further studies will be necessary in order to determine its efficacy and tolerance in infants.

Adolescent↗

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.

Adolescent↗

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.

Adolescent↗

Bronchiectasis in a child after acrolein inhalation.

Acrolein is an unsaturated aldehyde produced by combustion of many organic compounds. Massive exposure may lead to severe pulmonary disease and possibly death. We report a case of intoxication in a 2-year-old boy; an 18-month follow-up showed development of obstructive bronchiolar disease with diffuse bronchiectasis.

Accidents, Home↗

[Vaccinations of children allergic to eggs with vaccine prepared with egg].

BACKGROUND: The mumps, influenza, yellow fever and measles vaccines are grown in chick-embryos. Because allergic reactions to these vaccines have occasionally been reported in children who have suffered anaphylaxis from egg ingestion, it has been claimed that these children should not receive such vaccines. PATIENTS AND METHODS: 17 egg-allergic children aged 1 year 1 month to 7 years 10 months (mean 2 years 4 months) were studied. All had developed an allergic reaction less than one hour after egg ingestion. Allergy was confirmed by skin testing (prick skin test) and detection of IgE antibodies to egg (RAST). RESULTS: Seven children were immunized normally by their general practitioner, who was not aware of their allergy; 8 children having negative prick skin and intradermal tests with the vaccine were also immunized normally while 2 children who had positive intradermal test with the vaccine received divided doses following a protocol established for this study. None of these 17 egg-allergic children developed local and/or general reactions. Reintroduction of egg (yolk then white) was tested on the day of immunization in 4 children: only one developed facial edema. CONCLUSION: This protocol permits these vaccines to be safely given to egg-allergic children.

Child↗

[Toxicity of fire smoke. Apropos of 2 pediatric cases].

BACKGROUND: Smoke inhalation is one of the main cause of respiratory problems in fire-related accidents. CASE REPORTS: Case 1. A girl, aged 11 months, was found in her apartment 15 minutes after the start of accidental fire. She was in a stage I coma with cyanosis and covered with soot. She was placed on oxygen and given hydroxocobalamin. Aggravation of respiratory problems led to mechanical ventilation. Tracheobronchoscopy showed deposits of soots with moderate burnt lesions. Intubation was discontinued 12 hours later, but the child remained oxygen-dependent, with persistent tracheobronchitis, despite steroid therapy for 2 weeks. Case 2. Another girl, aged 4 1/2 years, was found in the same room as the preceding patient. She was also covered with soot, and in a coma (Glascow score = 11). She was intubated, placed on mechanical ventilation, and given hydroxocobalamin. Tracheobronchoscopy revealed similar changes to those seen in the preceding patient. Despite repeated tracheobronchial washings and steroid therapy, respiratory problems persisted with thoracic distension and pneumothorax. Mechanical ventilation was discontinued 16 days later but at 5 1/2 years, this child still has dyspnea and has developed bronchiectasis. CONCLUSION: Bronchopulmonary changes can be a severe complication of smoke inhalation during fires, and require early mechanical ventilation and repeated tracheobronchoscopy.

Carbon Monoxide Poisoning↗

Serum bactericidal test as a prognostic indicator in acute pulmonary exacerbations of cystic fibrosis.

The serum bactericidal test has been used for many years for optimal assessment of the efficacy of antibiotic therapy in patients with infective endocarditis and other bacterial infections. Its capacity to predict the bacteriological outcome of acute pulmonary exacerbations in patients with cystic fibrosis was evaluated. A total of 54 courses of intravenous antibiotic therapy were analyzed in 22 patients, whose ages ranged from 4 months to 24 years (mean age: 10 years). The serum bactericidal activity of blood samples, taken at expected peak and trough antibiotic levels on day 4 of therapy, were determined against the potentially pathogenic strains isolated in sputum at the time of admission. For 104 isolates (64 Pseudomonas aeruginosa, 28 Staphylococcus aureus, and 12 Haemophilus influenzae strains), the peak and trough bactericidal titers were compared to bacteriological outcome. Bacteriological success was defined as a decrease of 2 log10 units or more in the bacterial density in sputum between days 0 and 7 of therapy. At peak antibiotic levels, serum bactericidal titers of 1:128 or more were 96% (all isolates) and 89% (P aeruginosa isolates), predictive of cure, whereas serum bactericidal titers of less than 1:16 were 100% predictive of failure for all infecting bacteria. In patients aged less than 18 years, the best peak titer for predicting success was 1:64, with a predictive value of 96% for titers of 1:64 or greater. The peak titer that best predicted success in patients aged 18 years or more was 1:128, with a predictive value of only 83% for titers of 1:128 or greater.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

[The asthmatic child].

Asthma is the most frequent chronic pediatric disease. Management is based on assessment of severity and should normalize lifestyle as well as pulmonary function. Mild asthma is treated with intermittent beta-2-agonists. Moderate asthma should receive non-steroids prophylactic anti-inflammatory drugs. Immunotherapy should be considered. Severe asthma requires inhaled steroids. At each stage inhaled medications should be preferred. Therefore inhalation delivery system must be adapted for children of different ages and degree of dyspnea. The importance of environment control is well recognized. Establishing a partnership with the child and its family and with the medical staff and with the child's school is always necessary.

Asthma↗