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Biomedical subjects

J C Dubus

Publications and source records attributed to J C Dubus.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Acute asthmatic crisis in children].

Acute asthma attack in children is an attack responsible for life-threatening acute respiratory distress with partial or no response to bronchodilator drugs. The severity of the episode needs to be quickly evaluated. This presupposes a perfect knowledge of the clinical signs of severity. Treatment is urgent and first based on the administration of high doses of inhaled short-acting beta 2-agonists. In the more obstructed children, anti-cholinergic drugs can be added to nebulized beta 2-agonists. Because of their delayed effect, systemic steroids require an early prescription. Symptomatic treatments are: urgent hospitalization, oxygen if needed, proper hydratation. Continuous nebulization or intravenous perfusion of beta 2-agonists are prescribed with cardiac monitoring when no objective improvement is noted. Admission into the pediatric intensive care unit when bronchial obstruction continues will permit the association of bronchodilator drugs and the proposal of mechanical ventilation if needed. When the episode is resolved, a prophylactic treatment using inhaled corticosteroids must be prescribed. Clinical and spirometric follow-up has to be organized, and the patient and his/her family have to be educated.

Acute Disease↗
PubMed2000

[Role of leukotriene inhibitors in the treatment of childhood asthma].

Leukotriene inhibitors are new pharmacological agents for the treatment of mild to moderate persistent asthma and exercise-induced asthma (EIA). Studies concerning their use in children remain scarce. Available data in the treatment of persistent asthma in children suggest that they could be an alternative to long-acting beta 2-agonists when asthma control cannot be obtained with inhaled steroids alone. Their main advantages are first that they are given orally once daily; second, that they do not induce tachyphylaxis to bronchoprotection against EIA, unlike long-acting beta 2-agonists. Studies specifically conducted in children are necessary to best describe their place in pediatric asthma treatment.

Administration, Oral↗
PubMed1999

Bronchial challenge with carbachol in 3-6-year-old children: body plethysmography assessments.

Several studies of airway responsiveness in young children (3-6 years old) have been reported, but few have attempted measurements of airway resistance by body plethysmography. Therefore, we decided to study nonspecific bronchial responsiveness following cumulative doses of inhaled carbachol in 44 children with clinical asthma (CA group), 44 children with chronic cough (CC group), 38 children with wheezy bronchitis in the first 2 years of life (WB group), and 40 controls. Specific airway resistance (sRaw) was measured in a body plethysmograph, and specific airway conductance (sGaw=1/sRaw) was calculated. Two parameters were used to assess individual bronchial responses: 1) PD100 (the dose of carbachol which induced a 100% increase in sRaw), and 2) bronchial reactivity (BR), i.e., the slope of the log-dose sGaw response to carbachol. Significant differences were observed in PD100 and BR between the control group and the three groups of young patients (P < 0.001). Moreover, PD100 of the CA group was significantly lower than in the CC group (83.1 +/- 7.8 microg vs. 108.0 +/- 10.2 microg, respectively, P < 0.05), but was similar to the WB group PD100 (94.4 +/- 8.5 microg). BR in the CA group was significantly higher than in both the CC and WB groups (0.127 +/- 0.009 cm H2O-L.sec(-1) x log microg(-1) vs. 0.073 +/- 0.006 cm H2O(-1) x sec(-1) x log microg(-1) and 0.082 +/- 0.006 cm H2O(-1) x sec(-1) x log microg(-1), respectively, P < 0.001). Repeatability and coefficients of variation were always acceptable. Continuous SaO2 monitoring in some children of the CA group demonstrated the safety of the method, which is proposed as a technique in future studies.

Asthma↗
PubMed1999

Pulmonary anthracosis in children.

We report two cases of children with malignancies and subpleural nodules found on computed tomography (CT) scan. In both cases the diagnosis was anthracosis. This pathologic condition has never been reported in children. Causes of anthracosis include a smoking environment, living in urban areas and air pollution.

Air Pollutants↗
PubMed1999

[Ontogeny of the immune system].

The newborn immune system differs quantitatively and functionally from adults. At birth, the immune system is partially immature, resulting in deficiency in cell-mediated cytolysis, immunoglobulin synthesis and cytokine production. The most clearly defined deficit in neonatal phagocytosis defenses is diminished neutrophil storage. T cell function is diminished, including T cell-mediated cytotoxicity and T cell help for B cell differentiation. Selective decreases in cytokine production by T cells may contribute to all of these deficits. One of the fundamental differences between adults and newborns for T cell functions resides in whether or not the patient had prior exposure to antigens. Significant immune responses to antigens can be obtained in the neonatal period. These responses are qualitatively different from those induced in adults with a predominance of TH2 pattern.

Adult↗
PubMed1999

[Respiratory allergy in children and passive smoking].

Environmental tobacco smoke interacts with the respiratory mucosa by irritation and/or inflammation. Environmental tobacco smoke seems also modulate humoral and cellular immune activity. Thus, environmental tobacco smoke, in all children, increases the risk of superior and inferior airway infections, modifies the growth and the natural evolution of the respiratory function, increases the occurrence of asthma and exacerbates the symptoms of asthma, and creates or exacerbates a bronchial hyperresponsiveness. In atopic children (defined by the presence of at least one positive allergy skin test), environmental tobacco smoke increases the risk of respiratory allergy and exacerbates the symptoms of respiratory allergy. Parental environmental tobacco smoke is a universal toxic which must be avoided in both allergic and non-allergic children.

Adolescent↗
PubMed1999

Urinary cotinine and exposure to parental smoking in a population of children with asthma.

BACKGROUND: Studies of the effects of tobacco smoke often rely on reported exposure to cigarette smoke, a measure that is subject to bias. We describe here the relationship between parental smoking exposure as assessed by urinary cotinine excretion and lung function in children with asthma. METHODS: We studied 90 children 4-14 years of age, who reported a confirmed diagnosis or symptoms of asthma. In each child, we assessed baseline pulmonary function (spirometry) and bronchial responsiveness to carbachol stimulation. Urinary cotinine was measured by HPLC with ultraviolet detection. RESULTS: Urinary cotinine concentrations in the children were significantly correlated (P <0.001) with the number of cigarettes the parents, especially the mothers, smoked. Bronchial responsiveness to carbachol (but not spirometry test results) was correlated (P <0.03) with urinary cotinine in the children. CONCLUSION: Passive smoke exposure increases the bronchial responsiveness to carbachol in asthmatic children.

Adolescent↗
PubMed1998

[Non-antibiotic treatments for community-acquired pneumonia in children].

Besides antibiotic therapy (when warranted), treatment of acute pneumonia in children usually requires only simple measures, including: fractionated feeding, analgesic and antipyretic medications and detection of hypoxemia. There is no evidence that physical chest therapy, bronchial mucus modificators and corticosteroid therapy are really useful. The best prevention relies upon vaccinations, suppression of passive smoking, and hygiene and nutritional improvements.

Acute Disease↗
PubMed1998

Possible interaction between exposure to environmental tobacco smoke and therapy in children with asthma.

1. The aim of the study was to determine the carbachol and albuterol responsiveness in treated and untreated asthmatic and allergic children exposed to environmental tobacco smoke assessed by urinary cotinine measurements. 2. Forty-six asthmatic and allergic children with normal spirometric values were recruited. The doubling dose, concentration of carbachol producing a 2-fold increase in specific airway resistance (SRaw) was determined and 200 micrograms of albuterol were administered via a Volumatic(R) spacer. The percentage of bronchodilatation was defined as the difference between the largest obtained SRaw and the post-beta2 SRaw divided by the largest SRaw. Data were compared by a Mann-Whitney U-test. 3. The 23 children with a high urinary cotinine, compared with the 23 children without urinary cotinine, had a decreased doubling dose (108.2+/-14.7 micrograms versus 160.9+/-19.5 micrograms; P=0.04) and an increased percentage of bronchodilatation (74.8+/-1.4% versus 68.8+/-1.8%; P=0.03). A prophylactic anti-inflammatory treatment induced a weaker bronchial reactivity to carbachol and a slightly greater bronchodilatation in children exposed to environmental tobacco smoke. 4. Environmental tobacco smoke increases bronchial reactivity in asthmatic and allergic children. This effect might be reduced by anti-inflammatory therapy. The bronchodilator response may be enhanced in exposed children and may be caused by one or several direct interactions between tobacco smoke compounds and albuterol.

Adolescent↗
PubMed1997

[Influence of the inhaler device on bronchodilatation in the asthmatic child].

The use of spacer devices is recommended in asthmatic children for inhaled therapeutics. Therefore, in vitro studies prove the dependent-device delivery of the drug. The aim of this study was to compare, in vivo, the effect of 200 micrograms of albuterol, delivered via one of the five spacer devices currently marketed in France (Aerochamber, Aeroscopic, Babyhaler with a face mask, Nebuhaler or Volumatic) and assessed by the induced peak expiratory flow (PEF) change. One hundred asthmatic children were recruited and randomized in 5 groups. The mean age was 8.9 +/- 3.3 years. Each group was comparable regardless of gender, height, weight, characteristics of asthma and baseline PEF. The maximal change in PEF was obtained with Babyhaler (14.9 +/- 12.8%; p = 0.009). The increase in PEF elicited with Aeroscopic was 9.7 +/- 10.2%. The others spacer devices did not offer a change greater than the variation of PEF in the studied population. Further studies, concerned with a measurement of drug deposition or with an assessment of its use in obstructive episodes of asthma, are required, but Babyhaler with a face mask, usually reserved to infants, deserves to be advised to older children for salbutamol intake.

Administration, Inhalation↗
PubMed1995

[Thoracic standard radiology and x-ray computed tomography in mediastino-pulmonary tuberculosis in infants].

Primary mediastino pulmonary tuberculosis in infancy is increasing in France. Bacteriological diagnosis is difficult. The aim of the study is to assess the value of chest radiograph and CTscan for diagnosis of tuberculosis. We studied 15 infants, 3 month old to 18 month old, between November 1990 and June 1992. On plain film, lymphadenopathies were present in 13 cases and parenchymal disease in 10 cases, parenchymal nodular densities in 6 cases and pleural effusion in one case, displacement of the trachea in 6 cases. We found CTscan to be useful in delineating the lymphadenopathies and parenchymal changes. In 2 cases lymphadenopathies and in 2 cases alveolar condensation were discovered on CTscan as plain film was normal. In all cases lymphadenopathies were present in CTscan, often in right side and in all cases, lymphadenopathies were hypodense with peripheral enhancement. In conclusion, the association of right paratracheal nodes with displacement of trachea and alveolar consolidation is common in tuberculosis in infants. These findings when seen on chest radiographs must lead to perform a CTscan and suggest the diagnosis.

Bronchial Diseases↗
PubMed1994

[Pulmonary tuberculosis in infants. Apropos of 6 cases].

BACKGROUND: The present increased incidence of tuberculosis in children can be explained by contacts with infected adults and/or late BCG vaccination. PATIENTS: Six infants, 3 to 18 months-old (mean: 8 months), were admitted from November 1990 to May 1992 for various reasons; only two were admitted with a diagnosis of tuberculosis based on tuberculin test and only one was given a BCG vaccine. The disease produced a broad range of symptoms. Diagnosis was based on tuberculin test and radiographic examination showing lymph node enlargement of mediastinum and segmental consolidation lesions. Mycobacterium tuberculosis was found in two cases. The patients were given isoniazid, rifampin, ethambutol and/or pyrazinamide; corticosteroids were added in five patients. Each patient received four or three drugs for 2-4 months and two drugs (isoniazid plus rifampin) beyond, for a mean total duration of 13 months (range: 9-17 months). Repeated CT scan of thorax was performed to evaluate the efficacy of treatment. Tuberculosis was diagnosed in 11 subjects in contact with these children. CONCLUSION: Tuberculosis in children is not rare, and BCG vaccination of neonates should be seriously considered.

BCG Vaccine↗
PubMed1993

Fever-induced changes in theophylline pharmacokinetics in rats.

Our aim was to document possible alterations of theophylline pharmacokinetics in rats during fever. Two groups (group A = normothermic controls, group B = fever-induced animals) of Wistar AF IOPS male rats were injected at 19 30 h either with 2 g/kg of brewer's yeast subcutaneously (20% w/v) or with the equivalent volume of saline. Twelve hours later at 07:30 h the two groups received a single 12 mg/kg/IP dose of theophylline. Blood samples were obtained by retro-orbital sinus puncture 0, 0.25, 0.5, 1, 2, 4, 8, 12, 16 and 24 hours after administration. A third group of 10 male IOPS rats (group C) were used under the same experimental conditions in order to determine the influence of brewer's yeast-induced fever on biological parameters. Cmax, Tmax, Cmax/Tmax, T 1/2, Cl, Vd and AUC were determined according to a one-compartment open model. Our results confirm the fever-induced decrease in total plasma proteins and albumin but do not demonstrate any significant change in theophylline pharmacokinetic parameters.

Animals↗