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Biomedical subjects

G Tournier

Publications and source records attributed to G Tournier.

At least 73 records · Page 4Linked to original sources
PubMed1988

Activation of alveolar macrophages from children with the acquired immunodeficiency syndrome-related complex.

The ability of alveolar macrophages (AM) to release hydrogen peroxide (H2O2), an indicator of AM function, was studied in five children with the acquired immunodeficiency syndrome (AIDS) related complex and, for comparison, in 11 children without disorders of the lung parenchyma. In the AIDS-related complex group, pulmonary manifestations were mild, and lung involvement was suspected by moderate clinical and/or radiological features. None had a past history of opportunistic infections; neither did any have lymphopenia. Cytologic study of the bronchoalveolar lavage (BAL) fluid revealed increased cellularity with increased percentage of lymphocytes. The study of H2O2 release was performed on unstimulated AM and on AM stimulated by phorbol myristate acetate (PMA). Under both experimental conditions, the amount of H2O2 accumulated in the medium was significantly increased in the group with AIDS-related complex (P less than 0.001). As no enhanced oxidative activity has been reported in AM from patients with full-blown AIDS, an increased ability of AM to release oxygen metabolites from children with AIDS-related complex may reflect an initial and temporary step in the course of the LAV/HTLV-III pulmonary disease. Determining AM activation might be a reliable method of assessing the evolution of lung disorder in AIDS.

AIDS-Related Complex↗
PubMed1988

Alveolar macrophage status in bronchopulmonary dysplasia.

The predominant inflammatory cell type within the alveolar structure in bronchopulmonary dysplasia (BPD) is the alveolar macrophage (AM). AM ability to release hydrogen peroxide, a way to evaluate the cell status, was studied in nine infants who developed clinical and radiological evidence of BPD, and was compared to those from infants without lung parenchymal disorders (n = 6). AM were collected by bronchoalveolar lavage which was done after the mechanical ventilation stage in the BPD group. The experiments were performed on unstimulated AM and on AM stimulated by phorbol myristate acetate. Results revealed that the amount of hydrogen peroxide accumulated in the culture medium was significantly enhanced in the BPD group, in both experimental conditions (p less than 0.01 and less than 0.001, respectively). Furthermore, improvement of patients treated with glucocorticoids was closely related to a reduction of the alveolitis with a decrease of AM ability to generate hydrogen peroxide. These data indicate that AM activation is a central component of alveolitis in BPD and that extracellular production of oxidants by stimulated AM may play a critical role in the pathogenesis of the disease.

Bronchopulmonary Dysplasia↗
PubMed1988

[Treatment of childhood asthma].

The treatment of childhood asthma should be considered with respect to age, severity and aetiology. Treatment should be instituted early from the first crisis in order to avoid progression to a more severe form. It consists of two aspects: the treatment of the acute episode and the chronic treatment. The treatment of the acute episode consists of using bronchodilators (BD) (rapid release Theophylline and/or beta agonists) to which one might add corticosteroids if the crisis lasts for more than a few hours or seems severe at the outset, an antibiotic should also be used as infection is often a trigger factor in infants. Maintenance treatment is necessary in asthmatics with frequent exacerbations. It should be tailored to the symptomatology and aetiology. The symptomatic treatment consists of a bronchodilator (slow release Theophylline or an atropine-like pharmacological derivative) to which one may add, in severe cases, corticosteroids which may be in the form of aerosol, or as rarely as possible by mouth. The second aspect of treatment relating to the aetiology is the most difficult to apply as childhood asthma is often multi-factorial: in allergic asthma the avoidance of allergens, disodium cromoglycate, ketotifen, and if necessary specific desensitization. In non-allergic asthma, physiotherapy, treatment of infectious foci, particularly ENT (ORL), and attention to psychosomatic features. When asthma is diagnosed and treated early the prognosis is transformed and progress towards chronicity is avoided.

Adrenergic beta-Antagonists↗
PubMed1988

[Prenatal diagnosis and genetic diseases of the lung].

Currently two genetic pulmonary disorders can be diagnosed before birth: alpha-1-antitrypsin deficiency and mucoviscidosis. For the latter there are two possible diagnostic techniques: first a study of the intestinal enzymes of the amniotic fluid, a reliable method only at the 18th week, and also a study of DNA markers (ADN) of the trophoblastic cells using molecular biological techniques: this can be performed from the 10th to 11th week of pregnancy but presupposes a family study in which there is already a subject suffering from the disorder. Foetal echocardiography enables various pulmonary abnormalities to be detected: pleural effusion, cyst, pulmonary hypoplasia and other disorders. This technique however has some limits, at least at present. Most often these severe malformations are revealed at birth such as respiratory distress or stillbirth. Adenomatous cystic malformations or congenital lobar emphysema, a posterior diaphragmatic hernia, and oesophageal atresia with oesophagotracheal fistula are the most frequent and are curable surgically.

Amniotic Fluid↗
PubMed1987

A controlled study of oxygen metabolite release by alveolar macrophages from children with interstitial lung disease.

The ability of alveolar macrophages (AM) to release O2 metabolites was studied in 8 children with interstitial lung disease (ILD), and in 11 children without lung parenchyma disorder. AM were collected by bronchoalveolar lavage. The experiments were performed on unstimulated AM and on AM stimulated by phorbol myristate acetate (PMA) or zymosan. Our results indicated that, with or without triggering agent, the amount of O2 metabolites release was a linear function pattern with time. The accumulation of superoxide anion (O2-) and hydrogen peroxide (H2O2) into the extracellular medium differed depending on the triggering agent used: with PMA, the amount of O2- released was threefold the amount of H2O2 detected in the medium, whereas with zymosan the O2- accumulation was tenfold higher than the amount of H2O2 measured. In patients with ILD, a significant increase in the amount of H2O2 release was observed for both unstimulated and stimulated AM (p less than 0.001). In this group, the measurement was repeated after a 2-month steroid treatment: prednisone had markedly improved the clinical, radiologic, and functional status of the patients, and this improvement was in good correlation with the decrease of O2 metabolite production. The amount of H2O2 release in each case was within the range of control values. Evaluation of O2 metabolite release by AM could be a useful parameter in the assessment of the activity of ILD.

Adolescent↗
PubMed1987

[Allergologic investigation of asthma in infants. Apropos of 153 cases of infants aged 5 to 36 months].

153 asthmatic children from 5 to 36 months (mean age: 26 months) were investigated. The aim of the study was twofold: 1) to determine the reliability and limits of an allergologic diagnosis before 36 months of age; 2) to compare the predictive value of skin-tests with other allergologic tests. Results were expressed according to a score involving 5 parameters derived from the allergologic investigation. Each parameter represented one point: atopic past history, increased level of total IgE antibodies related to the age, presence of blood specific IgE antibodies, blood hypereosinophilia. Infants were considered allergic if their score level was greater than or equal to 3. Concordance between this score level and each parameter was as follows: Positive skin-test 83%; Blood hypereosinophilia 82%; Presence of specific IgE antibodies 80%; Increased level of total IgE 78%; Familial history of atopy 54%. It is concluded that, in allergic infants, a significative link exists between positive skin-test plus the presence of specific IgE antibodies and an atopic disease. However, more children have to be enrolled in a multivariant analysis to assess definitively the predictive value to this score.

Asthma↗
PubMed1985

Inspiratory force reserve of the respiratory muscles in children with chronic obstructive pulmonary disease.

The purpose of this study was to evaluate inspiratory muscle force reserve in children with chronic obstructive pulmonary disease (COPD). In 15 hyperinflated (FRC/TLC, 65 +/- 0.7%) children, maximal mouth inspiratory static pressure (PImax) at FRC, mouth occlusion pressure (P0.1), tidal volume (VT), inspiratory time (TI), and total duration of the respiratory cycle (Ttot) were all measured. It was found that PImax at FRC was reduced compared with predicted values. However, after lung volume correction, PImax was in the normal range, and P0.1 was higher, TI was shorter, and Ti/Ttot was lower than predicted. The estimated mean inspiratory pressure for breathing at rest (PI) was significantly higher than predicted and was related to total pulmonary resistance (r = 0.74, p less than 0.001). The fraction of PImax developed by the respiratory muscles for breathing at rest (PI/PImax) significantly increased. The higher the PI/PImax ratio, the more the TI/Ttot ratio decreased (r = -0.64, p = 0.01). At rest, our subjects had to develop a mean inspiratory power (W) of as much as 48% (range, 30 to 76%) of the critical W above which fatigue occurs. Thus, even minimal increases in breathing load might expose children with COPD to respiratory muscle fatigue and to respiratory failure.

Adolescent↗
PubMed1985

Respiration during sleep in children with COPD.

Seventeen children (mean age, nine years) with chronic obstructive pulmonary disease (COPD) were studied during sleep. Electroencephalography, electrooculography, and electromyography were all recorded. Airflow was measured by nasal and oral thermistors, and abdominal and thoracic anteroposterior diameters by magnetometers. Transcutaneous partial pressure of O2 (tcPO2) and of CO2 (tcPCO2) were monitored. The average total sleep time was 283 min +/- 36 (1 SD). Breathing pauses (BP) five seconds or longer were measured. The mean time of BP expressed as a percentage of TST was 1.3 percent +/- 0.8 (1 SD). The BP occurred most frequently during REM sleep. Forty-six percent of BP were obstructive (OBP). The percentage of OBP was significantly related to the degree of lung resistance during wakefulness. Periodic breathing was observed with a mean frequency of 2.2 times per night (range: 0 to 7). Episodes with paradoxic inward rib cage motion were seen one to 29 times (mean 6.6). Drops in tcPCO2 greater than 5 mm Hg occurred one to eight times and 67 percent were observed during REM sleep. Compared to tcPCO2 during W the mean maximal decrease in tcPCO2 was 14 mm Hg (range 8 to 29). tcPCO2 rose with a mean maximal of 9.1 mm Hg (range 6 to 13). It was concluded that children with COPD had worsened gas exchange during sleep.

Child, Preschool↗
PubMed1985

[Cholesterol pneumopathy in children. Apropos of 3 cases. Possible role of chronic Epstein-Barr virus infection].

Three cases of cholesterol interstitial pneumonia in patients 3, 9 and 10 years of age respectively are reported. All three were born in Island of Reunion. Two were sisters. All had failure to thrive, dyspnea on rest and clubbing. Respiratory symptoms had appeared early in infancy. Open pulmonary biopsy was diagnostic. Prognosis was poor the boy dying at 4 years of age and severe respiratory insufficiency at 9 or 10 years in the two girls. Current etiological investigations were non contributory. However a profile of chronic infection with Epstein Barr virus (EBV) was found in each case while serological profiles ruled out infection with a virus of the herpes group virus (cytomegalovirus, herpes simplex). The possible role of EBV as an etiological agent of cholesterol pneumonia is discussed and genetic or environmental factors as well.

Biopsy↗
PubMed1985

[Ceftazidime absorption into bronchial secretions in mucoviscidosis patients].

Penetration of ceftazidime into bronchial secretions was studied in 23 patients, of which 18 had cystic fibrosis. Ceftazidime was used as the single drug for treating exacerbations caused by Pseudomonas aeruginosa. Dosage was 6 g/1.73 m2/day divided into three intravenous injections for 14 to 21 days. Bronchial secretion samples were obtained by fiber-optic bronchoscopy or physical therapy. Serum and bronchial secretion ceftazidime concentrations were assayed using a microbiological method. Ceftazidime concentrations in both media were lower in children than in adults : elimination half-life is shorter (1.7 h against 2.45 h in adults), extravascular distribution is faster, with earlier (1 h against 2 h in adults) achievement of the peak bronchial secretion concentration (2 micrograms/ml). The ratio of bronchial secretion concentration to concomitant serum concentration did not exceed 5% at the time of peak bronchial concentration. These results suggest that in cystic fibrosis patients, the faster and lower bronchial penetration of ceftazidime may be due to faster elimination as compared to adults. Although transient elimination of Pseudomonas aeruginosa was achieved in 12 study patients, our findings support the use of higher dosages or alternative administration modalities designed to increase in situ ceftazidime concentrations.

Adolescent↗