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C Voisin

Publications and source records attributed to C Voisin.

At least 19 recordsLinked to original sources
PubMed1995

The delayed respiratory consequences of inhaled radionuclides in population exposed to nuclear catastrophe.

Cytological analysis of bronchoalveolar lavage (BAL) and x-ray energy dispersive spectrometry of intercellular compounds were evaluated in 19 workers ("liquidators") commissioned to clean and contain the nuclear waste after the Chernobyl catastrophe in comparison with ten control subjects. Results showed a significant increase of neutrophils, small monocyte-like alveolar macrophages (AM) and AM with large black cytoplasmic inclusions. In addition, such mineral elements as Zr, Ce, Pr, Sm, Pa, PU and Cs were detected in AM phagosomes in liquidators. These elements were reported as markers of Chernobyl-type nuclear fuel. It is recognized that BAL gives access to particulate matter present in lung parenchyma. Thus, spectrometric analysis of AM inclusions can provide reliable information about the exposure to inhaled radionuclides seven years after the catastrophe.

Administration, Inhalation↗
PubMed1995

Secretion and mRNA expression of TNF alpha and IL-6 in the lungs of pneumoconiosis patients.

Exposure to coal-mine dust leads to coal workers' pneumoconiosis (CWP), characterized by the development of a perifocal and progressive fibrotic reaction. In order to confirm their in vivo participation in the pathogenesis of CWP, the expression of tumor necrosis factor (TNF) and interleukin-6 (IL-6) was evaluated in bronchoalveolar lavage (BAL) specimens collected from 12 patients with simple pneumoconiosis (SP) and six with progressive massive fibrosis (PMF), and in pulmonary tissue from one patient with SP and three with PMF. Expression of TNF and IL-6 was assessed using both in situ hybridization and immunohistochemistry. The number of positive cells found in BALF was significantly higher for patients with PMF (TNF = 55 +/- 6%; IL-6 = 46 +/- 12.8%) than for those with SP (TNF = 34 +/- 11.6%; IL-6 = 26 +/- 10.2%) or normal controls (TNF = 15 +/- 5.5%; IL-6 = 13.3 +/- 6%), and was correlated with cytokine concentrations in supernatants from alveolar macrophages (AM). In lung biopsies, the expression of messenger ribonucleic acid (mRNA) for TNF was associated with the presence of coal dust and was limited to lung macrophages; mRNA for IL-6 was detected in mononuclear phagocytes but also in other types of cells such as endothelial cells. Monokine synthesis was confirmed by immunohistochemistry. These data confirm that TNF and IL-6 production is increased in the lungs of pneumoconiotic patients. Moreover TNF and IL-6 expression was associated with the presence of coalmine dust particles, suggesting a direct role of mineral particles in the cytokine production and development of pneumoconiotic lesions in CWP.

Adult↗
PubMed1995

Ozone stimulates synthesis of inflammatory cytokines by alveolar macrophages in vitro.

Ozone (O3) is one of the major irritant oxidant gases in photochemical smog. In the present study, the in vitro effect of low concentrations of O3 (0.1 to 1 ppm) was evaluated on cell viability and cytokine secretion by alveolar macrophages (AM) from guinea pigs and healthy subjects. Cell injury was estimated immediately after O3 exposure by evaluation of ATP cell content (measured by bioluminescence) and lactic dehydrogenase (LDH) release in the culture medium. No cytotoxic effect was found: the ATP cell content of both guinea pig AM and human AM did not significantly change after O3 exposure and similarly the LDH release in the culture medium was unchanged. AM-derived cytokines (tumor necrosis factor alpha [TNF alpha], interleukin-1 beta [IL-1 beta], interleukin-6 [IL-6], and interleukin-8 [IL-8]) were evaluated in AM supernatants. O3 exposure was associated with a significant increase in cytokine secretion, with a peak value at 0.4 ppm O3. The exposure of the guinea pig AM to 0.4 ppm O3 for 60 min increased the IL-6 activity by 252 +/- 60% and TNF activity by 202 +/- 35%. The increase in monokine production by the human AM was 443 +/- 208% for TNF alpha, 484 +/- 171% for IL-1 beta, 383 +/- 147% for IL-6, and 226 +/- 45% for IL-8 after a 60-min exposure to 0.4 ppm O3. Lowest O3 concentrations (0.1 and 0.2 ppm) only increased TNF alpha secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1992

Effects of nickel hydroxycarbonate on alveolar macrophage functions.

The metabolic effects of different concentrations of nickel hydroxycarbonate (NiHC) on guinea pig alveolar macrophages (GPAMs) were investigated. Exposure to high concentrations of NiHC (6.25 and 12.5 micrograms 10(-6) cells) led to cell vacuolization. Morphological changes were associated with a dramatic reduction in the steady-state level of cellular adenosine triphosphate (ATP), i.e. ATP levels were reduced by 35% (P less than 0.001) and 53% (P less than 0.01), respectively. Low concentrations of NiHC (0.0625 and 0.125 microgram 10(-6) cells) did not induce morphological changes but increased cellular ATP content by 19% (P less than 0.01) and 12% (P less than 0.05), respectively. Effects of NiHC (0.125 and 6.25 micrograms 10(-6) cells) on cell oxidative metabolism were studied. The chemiluminescence was significantly increased (P less than 0.001) by the lower but not the higher concentration. A slight inhibition of total superoxide dismutase (P less than 0.05) and a decrease of catalase activity were demonstrated (P less than 0.05) for the high dose, while the low dose decreased the levels of reduced and total glutathione. In conclusion, the effects of NiHC on alveolar macrophages are characterized by an overproduction of free radicals for low concentrations and the depletion of cellular reserve energy, particularly ATP, for high concentrations.

Adenosine Triphosphate↗
PubMed1992

[Long-term tolerability of formoterol in chronic obstructive bronchopathies].

Formoterol aerosol, a long-acting new beta 2-mimetic was administered over a year at a dose of 12 micrograms twice daily, to 62 chronic obstructive bronchitics of mean age 66 +/- 6 years and of whom the basal VEMS was at 12,801 +/- 0.59. Clinical tolerance of the product was good with undesirable effects in 13 patients, the most frequent being shaking. No untoward effect was seen on systolic or diastolic arterial pressure, or the heart rate over successive visits at 1, 3, 6, 9 months and one year. Electrocardiographic surveillance found in only four patients electrical abnormalities that may be due to Formoterol, these were patients without previous cardiac problems but of advanced mean age. Functionally, a significant improvement of basal VEMS was noticed from the 6th month. The VEMS improved significantly after administration of 12 micrograms on successive visits, without tachyphylactic signs. Well tolerated, with functional benefits, Formoterol is a promising product amongst the long-acting beta 2-mimetics. Its usefulness and limitations in the basic treatment of these chronic bronchopathies remains to be defined.

Adrenergic beta-Agonists↗
PubMed1992

[Occupational dust exposure and chronic obstructive bronchopulmonary disease. Etiopathogenic approach to the problem of compensation in the mining environment].

In order to support the hypothesis of a causal relationship between exposure to respirable coal mine dusts and chronic obstructive pulmonary disease (COPD), investigations were performed to assess the biological disorders affecting the distal air spaces in coal workers with pneumoconiosis. Broncho alveolar lavage studies demonstrated a continual influx of mononuclear phagocytes loaded with mineral particles, associated with neutrophils in small number, in smokers as well as in non smokers. The alveolar macrophages were in activated state, spontaneously releasing various mediators, particularly interleukin I, Tumor necrosis factor alpha and superoxide anion. So, they appeared as responsible both for a chronic inflammation of the distal airways and for a protease-antiprotease imbalance leading to pulmonary emphysema, partly due to an oxidative inactivation of alpha 1 antiprotease inhibitor. In spite of additive effect of tobacco smoke, as shown by longitudinal studies of lung function in coal miners, it is now reasonable to consider the evidence of association between coal mine exposure and COPD to be sufficiently strong to infer causality, and to justify compensation for COPD in coal miners with or without radiological evidence of pneumoconiosis.

Coal↗
PubMed1991

Human alveolar macrophage antibacterial activity in the alcoholic lung.

Alcoholic individuals are predisposed to respiratory infections. However, mechanisms of perturbations leading to increased susceptibility to lung infections of individuals with alcoholic liver cirrhosis (ALC) are not fully understood. We studied the antibacterial activity and oxidant generation (before and after stimulation by phorbol myristate acetate or opsonized zymosan) of alveolar macrophages from 16 patients with ALC. Our results were compared with those obtained from 12 healthy control subjects, from 8 patients with primary biliary cirrhosis (PBC), and from 8 alcoholic individuals without cirrhosis. All were nonsmokers, had normal chest X-rays, and did not present evidence of lung infection 3 months before. The total number of cells recovered by bronchoalveolar lavage did not significantly differ between control subjects and patients. The cellular viability of alveolar macrophages (trypan blue exclusion) was greater than 90% in all cases. The antibacterial activity of alveolar macrophages versus Staphylococcus aureus was severely impaired in ALC (-21 +/- 8.2%) whereas it was normal in PBC (52 +/- 4.2%), in alcoholic subjects (44.6 +/- 5.4%), and in control subjects (60 +/- 5.5%). The same pattern of results was observed versus Escherichia coli (-47.7 +/- 10,28 +/- 8,28 +/- 12, and 29 +/- 8.5%, respectively). Previous incubation of normal alveolar macrophages with serum or BAL fluid from ALC patients or with normal serum or normal BAL fluid did not result in a significant decrease in antibacterial activity of normal alveolar macrophages. To distinguish ingested bacteria from adherent extracellular bacteria, cells that had been incubated with bacteria for 90 min were then incubated with lysostaphin (1 microgram/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Production of tumor necrosis factor-alpha and interleukin-6 by human alveolar macrophages exposed in vitro to coal mine dust.

Following our previous demonstration of cytokine secretion by alveolar macrophages (AM) from coal miners and from patients with coal workers' pneumoconiosis, we investigated the effect of in vitro exposure to coal dust and to its silica content on tumor necrosis factor-alpha (TNF), interleukin (IL)-1 beta, and IL-6 production by normal human AM. TNF and IL-1 beta concentrations were estimated by a specific radioimmunoassay, while IL-6 levels were evaluated by the proliferation of 7TD1 cells. After 24-h culture, coal dust triggered a significant release of TNF and IL-6 at the dose of 0.1 mg/ml and more obviously at 1 mg/ml in comparison with titanium dioxide (TiO2), used as a biologically inert control dust (with 1 mg/ml of dust: 3,526 +/- 3,509 versus 330 +/- 138 pg TNF/ml and 224 +/- 74 versus 72 +/- 34 U IL-6/ml, respectively; P less than 0.01 in both cases). After 3-h culture, a significant TNF secretion as well as an increased TNF mRNA expression were also detected for AM stimulated by coal dust at variance with TiO2. In contrast, no modification of IL-1 beta concentration could be evidenced in AM exposed to coal dust, although we detected an increased expression of specific mRNA expression. In order to define the role of silica among the main components of coal dust in AM activation, we evaluated the effect of silica (alpha-quartz, 30 micrograms/ml, which is the concentration and the type of silica present in our coal dust) alone or mixed with TiO2 (1 mg/ml) on monokine production.(ABSTRACT TRUNCATED AT 250 WORDS)

Cells, Cultured↗
PubMed1991

Oxidative inactivation of alpha 1-proteinase inhibitor by alveolar macrophages from healthy smokers requires the presence of myeloperoxidase.

The aim of this work was to study the ability of human alveolar macrophages (AM) of 10 healthy smokers to inactivate alpha 1-proteinase inhibitor (alpha 1PI). Purified alpha 1PI was incubated for 45 min, with human alveolar macrophages before and after stimulation by phorbol myristate acetate (PMA) or opsonized zymosan. As a positive control, the same experiments were performed in parallel with blood human neutrophils (PMN). Results are expressed as percentage of inactivation of alpha 1PI as evaluated from its inhibitory activity against porcine pancreatic elastase. A strong correlation (r = 0.99) was shown when inhibitory activity of alpha 1PI was evaluated against porcine pancreatic elastase or human neutrophil elastase. Unstimulated AM (1.57 +/- 0.9%) as well as stimulated AM (PMA: 1 +/- 0.4%; zymosan: 3 +/- 0.6%) were unable to inactivate alpha 1PI. Gel electrophoresis of alpha 1PI demonstrated that AM before or after stimulation induced a slight proteolysis of alpha 1PI, whereas both cleaved and complexed alpha 1PI were found when alpha 1PI was incubated with activated PMN. Both unstimulated (22 +/- 2.6%) and activated PMN (PMA: 91.7 +/- 4.7%; zymosan: 90 +/- 5.5%) were responsible for a significant inactivation of alpha 1PI. Catalase, in contrast to superoxide dismutase, was responsible for a near complete protection of alpha 1PI inactivation by PMN. To better determine the role of PMN secretory products, especially myeloperoxidase (MPO), we also investigated the effect of zymosan-activated PMN supernatants or of purified MPO on the alpha 1PI-AM reaction. MPO assay in PMN supernatants demonstrated that activated neutrophils released significant amounts of MPO (16.8 +/- 4.1 U/ml), whereas MPO was undetectable in activated AM supernatants.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[In vivo kinetics of cotrimoxazole in alveolar macrophages].

The aim of this work was to study the kinetic of intramacrophage penetration of cotrimoxazole in guinea pigs which had received 100 mg/kg of sulfamethoxazole and 20 mg/kg of trimethoprim after a single intraperitoneal injection. 30 minutes, 1, 3, 6 and 24 hours after this injection an intra-cardiac blood sample was taken and pulmonary lavage was performed immediately after sacrificing the animal by cervical cord dislocation. The level of trimethoprim and sulfamethoxazole was measured in each sample by high performance liquid chromatography (HPLC). An estimation of the dilution of the supernatant was obtained by comparing the supernatant glucose with the serum glucose. The serum kinetics of trimethoprim and sulfamethoxazole progressed in a parallel fasion with time with a maximal concentration at 30 minutes (for trimethoprim: 6.7 +/- 0.9 micrograms/ml and for sulfamethoxazole 176.1 +/- 16.2 micrograms/ml). On the other hand their penetration capacity was different in the supernatant and in the alveolar macrophages: the maximal concentrations were obtained after one hour in the supernatant and after 3 hours in the cellular extract and were respectively for trimethoprim 0.43 +/- 0.07 microgram/ml and 20.9 +/- 8.06 micrograms/ml of intramacrophage water and for sulfamethoxazole 1.86 +/- 0.24 micrograms/ml and 23.8 +/- 12.7 micrograms/ml of intramacrophage water. A concentration around six times greater was noted for the trimethoprim inside the cells compared with serum and was only 0.25 time for sulfamethoxazole. On the other hand the supernatant/serum ratio showed a greater concentration for trimethoprim (4 to 10) than for sulfamethoxazole (0.6 to 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

The penetration of co-trimoxazole into alveolar macrophages and its effect on inflammatory and immunoregulatory functions.

The pharmacokinetics of co-trimoxazole in serum, bronchoalveolar lavage-fluid (BAL-fluid) and alveolar macrophages (AM) of guinea pigs receiving sulphamethoxazole (100 mg/kg) and trimethoprim (20 mg/kg) were studied. HPLC showed that peak co-trimoxazole levels were obtained in serum at 30 min, in BAL-fluid at 1 h and in AM at 3 h. A comparison between mean concentrations in serum, BAL-fluid and AM showed a six-fold higher concentration of trimethoprim in cells than in serum, but only 0.25-fold of sulphamethoxazole. The BAL-fluid/serum ratio was four to ten times higher for trimethoprim than for sulphamethoxazole (0.6-to-one-fold). Sulphamethoxazole/trimethoprim ratios (30 min, 1 and 3 h) were lower in BAL-fluid (4.9 +/- 0.5) and in AM (1.4 +/- 0.5) than in serum (30.7 +/- 1.6). The influence of co-trimoxazole in vitro on microbicidal capacities (superoxide anion and hydrogen peroxide generations), immunoregulation (production of interleukin 1) and pro-inflammatory agent production (tumour necrosis factor) of guinea pigs' AM was also studied. No significant effect of co-trimoxazole on superoxide anion and hydrogen peroxide generations, or on interleukin 1 and TNF production, was demonstrable.

Animals↗
PubMed1990

Coal worker's pneumoconiosis: CT assessment in exposed workers and correlation with radiographic findings.

To study the signs of coal worker's pneumoconiosis (CWP) at computed tomography (CT), the authors obtained thoracic CT scans in 170 coal-dust-exposed workers who were concomitantly evaluated with conventional posteroanterior and lateral radiography. The profusion and extent of disease was assessed by means of CT in two groups of miners: group 1 (n = 86), miners with worker's compensation and radiographic evidence of CWP, and group 2(n = 84), miners who had applied for compensation without radiographic evidence of CWP. The CT signs of CWP consisted of micronodules, nodules, and progressive massive fibrosis. The comparative analysis demonstrates the superiority of an optimal CT technique over chest radiography in the evaluation of simple silicosis, with improved sensitivity in the detection of small parenchymal opacities. CT provides additional information on the stage of the disease but also clarifies some ambiguities of the ILO classification of small opacities. CT was equivalent to radiography for complicated silicosis, except in the identification of necrosis. CT evaluations are complementary to plain radiography in the assessment of CWP, and the addition of high-resolution CT is useful in achieving a more accurate evaluation of the small parenchymal opacities.

Adolescent↗
PubMed1990

Superoxide anion generation by alveolar inflammatory cells in simple pneumoconiosis and in progressive massive fibrosis of nonsmoking coal workers.

We have examined superoxide anion (O2-) release by alveolar inflammatory cells recovered by bronchoalveolar lavage from the lower respiratory tract of 10 healthy nonsmokers and 25 nonsmoking pneumoconiotic patients, 11 with radiographic changes of simple pneumoconiosis (SP) and 14 with changes of progressive massive fibrosis (PMF). Significant increased number of cells was recovered from the lower respiratory tract from both patients with SP or with PMF. Alveolitis was made up predominantly of alveolar macrophages (AM) and an increased percentage of neutrophils in patients with PMF (3.3 +/- 0.7%). O2- release was evaluated using a superoxide dismutase (SOD)-inhibitable lucigenin-dependent chemiluminescence method. Spontaneous O2- generation by alveolar inflammatory cells from pneumoconiotic patients with SP was three to four times greater than that from 10 age-matched, healthy control subjects. O2- release by alveolar inflammatory cells from patients with PMF was dramatically increased when compared with that in patients with SP and with that in control subjects and was observed before and after stimulation by phorbol myristate acetate (PMA) (p less than 0.001). The increased O2- release was not due to a lack of enzyme antioxidant system within AM since intracellular superoxide dismutase was not lower in AM from patients than in AM from control subjects (p less than 0.05). Alteration of DLCO correlated with PMA-induced superoxide release by alveolar inflammatory cells in patients with PMF (p less than 0.05). Our data demonstrate that alveolar inflammatory cells from pneumoconiotic patients with PMF are in the activated state and release more oxygen-reactive species that do those from patients with SP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Abnormal secretion of interleukin-1 and tumor necrosis factor alpha by alveolar macrophages in coal worker's pneumoconiosis: comparison between simple pneumoconiosis and progressive massive fibrosis.

The aim of this study was to compare the secretion of tumor necrosis factor alpha (TNF alpha) and interleukin-1 (IL-1) by alveolar macrophages (AMs) harvested from patients with coal worker's pneumoconiosis (CWP) and control subjects. We observed higher levels of spontaneous TNF alpha and IL-1 secretion by AMs from patients with CWP than in those from healthy controls. We did not find any significant difference between the two groups in the incidence of simple pneumoconiosis and progressive massive fibrosis. In the group of coal miners without radiologic signs of pneumoconiosis, we found high levels of both cytokines in a subgroup of subjects still exposed to the mineral dust but not in the subgroup of subjects removed from exposure. These results indicate that AMs are involved in chronic lung inflammatory reactions to mineral dusts, partly by way of cytokine secretion. Moreover, cytokine secretion by AMs appears to be an early event that is detectable at the moment of mineral dust exposure. The results open new perspectives in the study of the mechanisms leading to CWP.

Bronchoalveolar Lavage Fluid↗
PubMed1990

[Mechanisms of pulmonary host defense].

Pulmonary host defenses prevent subglottic airways from bacterial colonization. Several mechanisms are involved. Some of these are purely mechanical or anatomical (cough, mucociliary clearance, epiglottis larynx). Others are rather biochemical (bactericidal and anti-adhesive properties of oropharyngeal and tracheobronchial secretions) or immunological (opsonization and phagocytosis). Distal airways and alveolar defenses are mainly conducted by alveolar macrophages which are directly involved as effectors of cell mediated immunity. They also have a key role in regulation of local and systemic immune responses. In critically ill patients failure of this mechanisms of defense is common, therefore predisposing to development of nosocomial infections.

Chemotaxis↗
PubMed1990

Subclinical alveolitis in immunological systemic disorders. Transition between health and disease?

A subclinical inflammatory alveolitis as assessed by BAL cell analysis may be present in a high proportion of symptomless patients with immunological systemic disorders and with normal chest roentgenogram. Subclinical alveolitis can be characterized by the relative proportions of the different cell populations comprising the alveolitis and by the activated state of the cells. Thus, subclinical alveolitis can be classified into two major groups: lymphocyte and neutrophil alveolitis. Lymphocyte alveolitis is frequently found in patients with extrathoracic granulomatosis (Crohn's disease, primary biliary cirrhosis, extrathoracic sarcoidosis) or with some collagen vascular diseases (Sjögren's syndrome, rheumatoid arthritis, systemic lupus erythematosus). Neutrophil alveolitis is a main finding in collagen vascular diseases, especially progressive systemic sclerosis, dermatopolymyositis and mixed connective tissue disease. In addition, alveolar macrophages may be spontaneously activated and release various mediators that could be relevant to the pathogenesis of interstitial lung disease. On the other hand, some other alveolar macrophage functions (antibacterial activity may be severely impaired in some diseases, for example systemic lupus erythematosus). Alveolar inflammation is associated with an increase in the permeability of the alveolar membrane responsible for an increased influx of blood proteins in the alveolar spaces. Although subclinical inflammation may also be detected by high resolution computed tomography (HRCT) scan and/or lung permeability scintigraphic studies, the significance and prognostic value remains unclear and clearly differs according to both the disease and the pattern of alveolitis.

Humans↗