PubMed Health⌕ Search

Biomedical subjects

B Melloni

Publications and source records attributed to B Melloni.

14 recordsLinked to original sources
PubMed1995

Work related distal airway obstruction in an agricultural population.

OBJECTIVE: To assess the prevalence of distal airway obstruction and its risk factors in agricultural areas. METHODS: A cross sectional study of respiratory symptoms and lung function was performed among French farmers and their spouses (1122 subjects) who came for preventive medicine examinations. They answered a respiratory questionnaire and performed pulmonary function tests on a portable spirometer. Diagnoses of chronic bronchitis were made on the basis of reported chronic respiratory symptoms. Airway obstruction was determined from predicted values. Odds ratio (OR) and linear regression coefficients were calculated after stratification by smoking and history of cardiac and other respiratory diseases. RESULTS: Of respiratory symptoms prevalence of chronic cough was 8.47%, and chronic bronchitis 7.66%. Prevalence of distal airway obstruction was 11.4%, and overall airflow obstruction 3.2%. Smokers were 20.2% men, and 5.7% women. Linear regressions showed high association between pack-years in smokers or exsmokers and forced expiratory volume in one second/forced vital capacity (FEV1/VC) and forced expiratory flow between 25% and 75% of vital capacity (FEF25-75). In non-smokers without any history of cardiac or respiratory diseases, age and the size of farms had the highest correlations with these variables. OR for distal airway obstruction was 2.1 in subjects > 50 years old v the younger ones and 3.02 in the smaller farms v the larger ones. CONCLUSION: After stratification by smoking and history of cardiac and respiratory diseases, distal airway obstruction is present in agricultural areas. The age, and the size of farm are the highest respiratory risk factors in non-smokers.

Adolescent↗
PubMed1995

Alterations of surfactant lipid turnover in silicosis: evidence of a role for surfactant-associated protein A (SP-A).

Type II cell hypertrophy with surfactant accumulation in the lung is a common observation in silicosis. Mechanisms leading to these alterations are poorly understood. By using silica dusts and alveolar fluids from saline and silica exposed sheep, we explored four different pathways of surfactant turnover in vitro: (1) synthesis and (2) secretion of lipids by rat type II cells; and dipalmitoylphosphatidylcholine (DPPC) uptake/reuptake by (3) type II cells and (4) alveolar macrophages. Silica had no direct specific effect on type II cell lipid metabolism. Alveolar fluids from both saline and silica exposed animals induced several alterations compared to control medium: (a) an increase in lipid synthesis (60 to 130%, P < 0.05); (b) a decrease in lipid secretion (25 to 70%, P < 0.05); (c) a 50 to 75% increase in DPPC reuptake by type II cells (P < 0.05); (d) a 65 to 75% decrease in DPPC uptake by alveolar macrophages (P < 0.05). DPPC uptake by in vivo silica exposed alveolar macrophages was reduced. Alterations of surfactant lipid metabolism induced by alveolar fluids from silicotic animals was more pronounced than in those treated with control fluids. Anti SP-A antibodies significantly suppressed most of the alveolar fluid induced effects on surfactant turnover. From these in vitro data, silica-induced type II cell hypertrophy seems to result from an increase in lipid synthesis activity and an imbalance in the lipid secretion/reuptake ratio.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1992

[Perceptions of consequences of chronic respiratory insufficiency in subjects over 65 years with home respiratory assistance. Apropos of 85 patients].

Chronic respiratory diseases (C.R.D.) induce changes in daily activities and mood for the patients who require respiratory assistance (oxygen delivery or ventilation). The aim of this study was to compare physical and social consequences of this disease. A self administered questionnaire was sent to one hundred patients, over sixty five years of age, who were affiliated with the "Association Limousine d'Aide aux Insuffisants Respiratories" (A.L.A.I.R.). The mean age was 72.4 +/- 0.66 (65-92), the mean PaO2 was 54 mm Hg +/- 0.2 (39-76). C.R.D. was stable during the study and treatments did not change. The questionnaire was composed of four scales and twenty-eight subjects; each item was weighed for importance. Subjects included: symptoms, mood, sleep, relationships with their wife or family, home activities. Eighty-five questionnaires were analysed. Reproductibility was good (92%) and non-responses to some questions was less than 10%. Coherence between the scales and the twenty-eight items was poor. Regression linear analysis found that only dyspnea was correlated with PaO2 (p < 0.007). For patients, the most important items were: abnormalities of home activities (37%), dyspnea (38%), relationships with their wife (39%) or family (45%), dependence (52%) and perception of A.L.A.I.R. (77%). Quality of life is an important concept for these patients with C.R.D. versus clinical symptoms. Perception of respiratory assistance is very good.

Activities of Daily Living↗
PubMed1992

[The influence of a new beta agonist: formoterol on mucociliary function].

The muco-ciliary apparatus has an essential role in the cleansing of the tracheo-bronchial tree of particulate matter. Disturbances linked to muco-ciliary function are well known in respiratory pathology and in cases of chronic bronchitis and asthma and lead to a reduced capacity for cleansing. In addition there are numerous pharmacological agents including sympathomimetics which are capable of altering the ciliary activity and the rheological properties of mucous. The role of Formoterol, administered as an aerosol has been assessed in vivo in 10 bronchitic patients who were in a stable state. After 6 days of treatment using the Formoterol aerosol the muco-ciliary clearance had significantly increased to 46% and was a real gain when compared to the muco-ciliary clearance measured on placebo. This gain was linked to a better function of the muco-ciliary carpet and not due to the bronchodilatation which was induced by Formoterol, because the penetration index did not change. At the same time the airway resistance was slightly reduced in a none significant fashion.

Administration, Inhalation↗
PubMed1991

[Tuberculosis and acute respiratory insufficiency. Apropos of 2 cases].

We report two cases of death from acute respiratory insufficiency of tuberculous origin. There were rare clinical presentations in which the clinical and radiological aspects were particularly atypical, suggesting a diagnosis of an acute respiratory distress syndrome. Bacteriological confirmation is necessary but it is worth considering this aetiology with each case of unexplained respiratory distress because the mortality is high and the prognosis is related to how early drug therapy is given.

Humans↗
PubMed1989

[Post-traumatic pulmonary hematomas. Apropos of 2 cases].

Post-traumatic pulmonary hematoma presents clinically as a hemorrhagic collection within a newly-formed cavity in the lung parenchyma. Its frequency is probably underestimated in view of the importance of the associated lesions. The most frequent clinical sign is hemoptysis. The chest radiograph, as well as the CT scan, shows a clearly defined round image. As a rule, there is a favorable outcome with slow resorption over several weeks, with a restoration of the integrity of the pulmonary parenchyma, which justifies simple observation, with an absence of any therapeutic intervention.

Adult↗
PubMed1988

[Does extrinsic asthma exist?].

Asthma cannot be triggered exclusively by external causes, even allergy. For it to develop, the subject must have pathological bronchial hyper-reactivity. On the contrary, however, asthma cannot be explained solely by intrinsic causes, metabolic or endocrine. It persists only in those subjects who have bronchial hyper-reactivity. The authors suggest a new definition of asthma, designed to replace the semi-logical definition of Charpin: Asthma is a dyspnoeic bronchospasmodic crisis that is linked with the existence of pathological bronchial hyper-reactivity.

Asthma↗
PubMed1987

[Pneumopathy caused by amiodarone. An often unrecognized iatrogenic entity].

Three cases of interstitial pneumopathy secondary to amiodarone are reported, in addition to almost 200 cases previously published in the literature. The main clinical, radiological, biological and evolutive characteristics are reminded in emphasizing the advantages of bronchioalveolar irrigation. Some factors seem to be predisposing, without any definite proof however. They are: high daily dosage, long term treatment, high cumulative dose, concomitant ingestion of another anti-arrhythmic medication, especially in elderly patients, and in patients who, before any treatment, presented a decreased total pulmonary capacity and a CO transfer capacity lower than 80 p. cent of the theoretical values. Discontinuation of amiodarone and administration of steroids usually produce a rapid regression of the clinical and radiological symptoms.

Aged↗
PubMedDate not supplied

Silica exposure induces cytotoxicity and proliferative activity of type II pneumocytes.

The contribution of the type II pneumocyte to the pathogenesis of silicosis is largely unknown. Prominent features of silicosis are hyperplasia and hypertrophy of type II epithelial cells, often accompanied by phospholipid accumulation in the lung. The biologic regulation of these events is poorly understood. This study addresses the question of a direct effect of silica on type II pneumocytes, since direct contact of the inhaled silica dust can occur in vivo. Type II cells were isolated from fetal rat lungs and their epithelial specificity was verified. Experiments were performed on 2nd passage monolayers in 2% serum. Repair, replication, and growth activity was evaluated by the incorporation of [3H]thymidine. Cytotoxicity was measured by quantitating the release of [14C]adenine and expressed as a cytotoxicity index (CI). Type II cell proliferation and cytotoxicity were evaluated for the mineral dusts silica (SiO2), aluminum-treated silica (SiO2AlK), and titanium (TiO2). Of these mineral dusts, only low concentrations of silica increased type II cell [3H]thymidine incorporation (silica 2.5 micrograms/mL: 52% above control, P less than .05; silica 20 micrograms/mL: 57% above control, P less than .02). In addition, silica increased the cell number significantly, although to a lesser degree. Exposure of the type II epithelial cells to silica dust for 24 h resulted in dose-dependent cytotoxicity (silica 10 micrograms/mL, CI = 9.1%, P less than .0002; 250 micrograms/mL, CI = 45.1%, P less than .0001). SiO2Al completely suppressed these proliferation and cytotoxicity effects, which were then similar to those of the inert dust, TiO2. These data suggest that direct exposure and contact of the type II pneumocytes to low-dose silica dust initiated repair, replication, and growth activity, while exposure to higher silica concentrations resulted in marked cytotoxicity. Both the repair, replication, and growth and the cytotoxic responses of the type II epithelial cells to silica exposure are related to the surface properties of silica.

Animals↗
PubMedDate not supplied

Silica-exposed lung fluids have a proliferative activity for type II epithelial cells: a study on human and sheep alveolar fluids.

The type II pneumocyte changes in silicosis are characterized by hyperplasic and hypertrophic epithelial cells, and increased surfactant phospholipids in the bronchoalveolar lavage fluids (BALF). To assess the proliferative activity of alveolar lining fluids, BALF were applied on type II cell cultures. The growth-promoting activity was studied by tritiated thymidine incorporation for 24 h, and the cell number was measured by an electronic counting after a 48-h exposure time. Human BALF from 3 subsets of workers exposed to silica, staged according to ILO classification (silica exposed-workers without disease: hSWD n = 6; workers with simple silicosis: hSS n = 7; workers with confluent silicosis: hCS n = 5), were compared to healthy volunteers (hC n = 6). Sheep BALF from our model of silicosis and control animals (sS and sC) were studied at months 0, 6, and 24 of exposure. A clear enhancement was found in type II cell DNA synthesis under the effect of either normal and silicotic human or sheep BALF, in comparison to the negative control (p less than .05). In addition hSWD and hSS BALF as sS BALF at 20% dilution (peak activity) were significantly more stimulating than the normal alveolar fluids from the same species (p less than .05). The highest sheep BALF stimulatory activity was found at month 6 (170% of increase vs control, p less than .05) and clearly correlated with the high cellularity of BALF. The thymidine incorporation was supported by changes in cell counts. Sheep silicotic BALF run through G50 columns identified at least 3 molecular weight (MW) areas of mitogenic activity between 30 and 5 kDa. Biochemical characteristics of growth factors in the above MW range (PDGF, FGF, TGF alpha, EGF) were tested. Increased mitogenic activity of type II cells eluted from heparin sepharose columns loaded with silicotic sheep BALF, at 0.5 and 1 M NaCl, corresponded to the removal areas of PDGF- and acidic FGF-like heparin-binding molecules. The high proliferative activity on type II cells of the latter two molecules, alone or in combination with other growth factors, was demonstrated in vitro (greater than 9 x control). In conclusion, a stimulatory activity for type II cell growth was found in the normal human and sheep alveolar lining fluid. This activity was clearly enhanced in the early stages of human and sheep silicosis. The BALF type II cell growth factors had biochemical characteristics consistent with the PDGF- and FGF-like molecules.

Animals↗
PubMedDate not supplied

Comparison between late onset and childhood asthma.

BACKGROUND: The onset of asthma frequently occurs after the age of 50 yr and the severity and causes of this late onset disease are poorly known. METHODS: 25 chronic asthmatics (65.7 +/- 6.5 yr) whose asthma started after the age of 50 yr were compared with 23 chronic asthmatic children (11.6 +/- 2.8 yr) and 24 COPD patients (61.6 +/- 3.4 yr). Both asthmatic groups had a similar apparent duration of asthma. None of the asthmatics was a smoker. All COPD were smokers. The severity of asthma was defined according to the Aas score. FVC, FEV1, MMEFR, Raw were tested and reversibility of bronchial obstruction was determined on Raw after salbutamol inhalation. Allergy was assessed by skin prick tests, RAST and total serum IgE (PRIST). RESULTS: Patients with childhood asthma had: 1) a significantly lower clinical severity of asthma; 2) a significantly less severe bronchial obstruction, and 3) a significantly greater reversibility than old age asthmatics. There was no significant difference between pulmonary function tests pre- and post-bronchodilators between COPD and old-age asthmatics. All asthmatic children and 40% of older patients were allergic. CONCLUSIONS: The occurrence of asthma in old age patients leads to a more severe course of the disease and allergy appears to play a role in many old age patients.

Adolescent↗