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Biomedical subjects

P Vaillant

Publications and source records attributed to P Vaillant.

30 records · Page 2Linked to original sources
PubMed1991

[Mechanisms of pulmonary fibrosis].

Lung fibrosis is characterized by the accumulation of extracellular matrix and mesenchymal cells leading a progressive loss of respiratory functional units. The accumulation of mesenchymal cells results from their migration and local replication. These cellular events are dependent upon the local presence of cytokines with chemotactic and/or mitogenic activity. The sequence of events leading the lung fibrosis is thought to result from a stereotyped response: after an initial injury, an inflammatory reaction develops and controls tissue repair through local production of cytokines. The permanency of these processes results in the development of fibrosis.

Acute Disease↗
PubMed1991

[Biopathology of fibrosing alveolitis].

Fibrosis is a condition where the functional tissue of an organ has been replaced by mesenchymal cells and their extracellular matrix. The process is frequent and may be regarded as univocal and independent of aetiology. An initial tissue damage is responsible for an inflammatory reaction which modulates and controls tissue repair with accumulation of mesenchymal cells, an accumulation which results from their migration and replication under the influence of chemotactic and/or mitogenic mediators (cytokines). Fibrosis occurs as an accentuation of this physiological process and may be understood as a healing process that has succeeded beyond normal expectation. Studies of idiopathic pulmonary fibrosis have improved our understanding of the physiopathology of pulmonary fibrosis. Alveolitis sets in response to an initial injury of undetermined nature, and from then on lymphocytes, neutrophils and macrophages intervene in the pathological process: (1) lymphocytes contribute to the perpetuation of the process by local production of immune complexes and coactivation of other inflammatory cells; (2) neutrophils and, to a lesser extent, eosinophils worsen the initial tissue injury by producing proteases and oxydants; (3) finally, macrophages control the local accumulation of mesenchymal cells by producing chemotactic and growth factors and by modulating the secretion by these cells of extracellular matrix.

Cytokines↗
PubMed1989

[Change in the lymphocyte subpopulations in bronchoalveolar lavage 72 hours after the allergen provocation test in the asthmatic].

Fourteen patients suffering from perennial allergic asthma linked to mono-sensitivity to the house dust mite were studied. An initial bronchoalveolar lavage with standard cytology as well as a study of the T lymphocyte subpopulations (CD3, CD4, CD8, Leu 7) and B cells (CD19) was carried out, representing the basal situation. Four weeks later an allergic bronchial provocation test to purified extracts of the house dust mite was performed taking care to monitor the occurrence of any delayed bronchial response (8 out of 14). A second bronchoalveolar lavage was performed 72 hours after the bronchial provocation test. A significant rise of eosinophils in the bronchoalveolar fluid was registered 72 hours after the provocation test; m +/- sem (%): 3.07 +/- 1.31 vs 7.78 +/- 1.22; p less than or equal to 0.005, Student t test for paired series. This large rise in eosinophils was observed independently of the type of response, whether immediate or biphasic. The CD4 lymphocyte subpopulations were significantly decreased after bronchial provocation tests m +/- sem (%) 12.21 +/- 2.79 vs 6.47 +/- 1.62; p less than or equal to 0.05 Student t test for paired series. There was no overall significant difference after the provocation tests in the CD8 lymphocyte subpopulation. However, a remarkable and significant rise was noted in the CD8 populations after bronchial provocation in 6 subjects presenting with an immediate isolated asthmatic reaction; m +/- sem (%) 10.17 +/- 4.01 vs 34 +/- 7.32, p less than 0.05, paired Wilcoxon test.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Severe complications related to metabisulfites].

Metabisulfite intolerance is encountered in 8 p. 100 of cases of extrinsic asthma and in 20 p. 100 of cases of the "aspirin triad" with nasosinusal polyposis, asthma and aspirin sensitivity. The possibility that anaphylactoid shock or acute severe asthma leading to status asthmaticus, might be related to sulfite sensitivity must be well known. Two case reports are set out. The first observation is that of a 35-year-old woman suffering from intrinsic asthma with alcohol intolerance, who developed status asthmaticus a few minutes after intravenous administration of Doxycycline associated with a metabisulfite preservative. The other 33-year-old patient presented with an acute bronchospasm in the course of a fiberoscopy using Lidocaine associated by mishap with epinephrine, as local anesthetic. The authors point to the miscellaneous drugs containing sulfites, that are employed in asthmatics by different routes, i.e. parenteral, oral, inhalational and other local treatments. Heavy metabisulfite intake may also arise from daily alcohol consumption. Sulfite intolerance could contribute to the persistence of chronic inflammatory processes in bronchial asthma and therefore should be systematically investigated.

Adult↗