Publications by authors named "Prevost M"

Listeria monocytogenes has the capacity to penetrate and multiply within professional and nonprofessional phagocytic cells, such as the Caco-2 human enterocytelike cell line. It was shown recently that shortly after listeriae have been phagocytosed, the phagosomal membrane is dissolved, probably by the action of the bacterial cytolysin listeriolysin O. The listeriae, which are then lying obviously free in the cytoplasm, become surrounded by a coat of actin filaments within a few hours.

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Cilofungin, a new biosemisynthetic analog of echinocandin B, inhibits the synthesis of beta-(1,3)-glucan resulting in severe modifications of the cell wall and cytoplasmic membrane of sensitive organisms. The morphological modifications to budding yeast cells, pseudomycelium, mycelium and germ tubes of Candida albicans were studied by scanning and transmission electron microscopy after 3 and 16 h exposure to cilofungin. Changes in yeast cell morphology were apparent after 3 h in 0.

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A total of 317 patients received loratadine, 10 mg once daily, terfenadine 60 mg twice daily, or placebo in a 14-day, double-blind, randomized study in seasonal allergic rhinitis. Four nasal and four nonnasal symptoms were evaluated. At the end point evaluation, mean total scores of combined nasal and nonnasal symptoms decreased from baseline (improved) 46%, 44%, and 35%, respectively, for loratadine, terfenadine, and placebo.

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Sugars and proteins are released from conidia of Cladosporium cladosporioides after incubation in various chemical solutions. Ultrastructural studies demonstrated that these exudates contained components from the outer wall layer and from internal compartments (inner wall and cytoplasm). The allergenicity of the extracts was evaluated using a passive cutaneous anaphylaxis test and radioallergosorbent test.

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We demonstrated the presence of lectins binding to glucose and N-acetylglucosamine on the surface of Conidiobolus obscurus spores by using glycosylated serum albumins substituted with fluorescent dyes and colloidal gold. The role of these exocellular lectins was examined in relation to the adhesion of the fungal spores to their host insect and the pathogenicity of the fungus.

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After 4 h hypoxia, platelet activating factor (PAF-acether or 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) and its deacetylated derivative, lyso-PAF-acether, accumulate in rat lung surfactant, the latter in a 1000-fold excess (Prévost, M.C., Cariven, C.

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The efficacy and safety of loratadine, 40 mg once daily, were compared with terfenadine, 60 mg twice daily, and placebo in controlling symptoms of ragweed hay fever. The study was a randomized, multicentric, parallel-group, double-blind design involving 280 patients divided into three groups receiving either loratadine, terfenadine, or placebo for a period of 14 days in the autumn of 1984. Both loratadine and terfenadine demonstrated a statistically greater reduction in symptom score compared to placebo.

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Sensitized guinea pigs produced specific IgG and IgE antibodies toward Cladosporium and Alternaria. In presence of fungal extracts, nasal mast cells degranulate. Ultrastructural modifications of the cells during degranulation have been established.

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The calculation of induced dipole moments and of their contribution to electrostatic effects in proteins is implemented following the approach of Warshel. Isotropic polarizabilities are assigned to individual atoms, and the resulting deviation from pairwise interactions is treated by a self-consistent iterative procedure. We give a detailed description of how the formalism is implemented in molecular mechanics and molecular dynamics simulation procedures, and report results based on calculations performed on crystal structures of crambin, liver alcohol dehydrogenase and ribonuclease T1.

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Using an anti-lignin peroxidase antiserum-protein A-gold complex, we found lignin peroxidase mainly intracellularly in several white rot fungi colonizing sawdust under laboratory conditions. This enzyme was also present in fungi found in naturally decayed wood. However, in all cases, lignin peroxidase was located mainly inside the fungal cells.

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1 The effect of the chemotactic peptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) was studied on cells in whole rabbit blood or on a mixture of purified rabbit platelets and neutrophils. 2 In blood, FMLP triggered cell aggregation (measured by electrical impedance) which was dependent upon the concentration of FMLP (9.9 +/- 0.

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The role of blood volume regulatory mechanisms located in the low pressure system in the control of urinary excretion was studied using hypobaric pressure breathing in normal and diabetes insipidus (Brattleboro strain with a congenital lack of vasopressin) rats. Rats were placed in an altitude simulator chamber for 4 h. A pump maintained pressure reduced to 701, 577 and 472 mbar simulating respectively altitude of 3,000, 4,500 and 6,000 m.

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The glomerular capillary wall of the kidney behaves as an electronegatively charged structure consisting of three layers, the lamina densa and the two laminae rarae, which are differently charged. Thus, a three layer model is proposed to analyse the transport of charged macromolecules across this wall. A modified Nernst-Planck equation describes the macromolecule flux across the wall and a Donnan equilibrium is assumed at each interface.

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The renal effects of clonidine (100 and 500 micrograms/kg s.c.) during acute hypobaric pressure breathing (i.

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Hypoxia provokes pulmonary constriction and because PAF-acether is a very strong pulmonary constrictor, we looked for PAF-acether in lung alveolar lavage (LAL) with a biological method based on the measurement of rabbit platelet aggregation. We first demonstrated a PAF-acether secretion during bronchoalveolar lavage with sterile isotonic NaCl (pH 7.2).

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The phospholipid content of bronchoalveolar lavage (LBA) has been little studied till now. This work involved 96 LBA on 7 cases of allergic alveolitis, 11 cases of diffuse interstitial fibrosis (FID) and 42 of sarcoidosis. The liquid collected was submitted to a cellular study (cellularity, total and differential) and biochemical (total proteins, total phospholipids separated into their different fractions by chromatography which enabled the identification of phosphatidyl-choline, phosphatidyl-serine and phosphatidyl-inositol in particular).

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We have studied, in the rat, the action of a vaporization with sulphurous water from Bagnères de Luchon on the surfactant modifications caused by hypoxia. The phospholipase activity, subordinate to hypoxia, decreased by 1/5 compared to its value without treatment and the phospholipid composition of the broncho-alveolar lung lavage remained unchanged whereas after hypoxia without treatment the phosphatidylcholines level decreases by 26%. We demonstrated by a dose-response study that this protective action decreased with the thermal water dilution.

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Two-beam interference fringes are not always able to give sufficient information to determine the topography of very weakly deformed wave surfaces. The process described allows us to intercalate several intermediate levels, which vary linearly in terms of the phase, between the brightness extrema of a fringe. The interference pattern is submitted to an optoelectronics treatment where the photoelectric signal is compared with an adjustable electric reference signal.

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The biochemical appearance of the alveolar border pathology, whatever the origin of the impairment may be, has become most important. This is the reason why we have studied the influence of hypobaric hypoxia, at a pressure of 370 mm Hg, on the phospholipids of pulmonary surfactant and alveolar macrophages. During the first hours we observed a decrease in the phosphatidylcholines of the pulmonary surfactant and a concomitant increase in the lysocompounds with simultaneous appearance of a phospholipase activity which seemed to have a macrophage origin.

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The authors study the influence of bromhexine metabolite VIII on phospholipid and fatty acid composition comparatively to controls. The subcutaneous injection of NA 872 produces on pulmonary surfactant an increase of 43% of total phospholipids. This change in the distribution of phospholipids is shown by the increase of 53% of phosphatidylcholines.

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The pulmonary sufactant was studied in the dog after crossed lobe autotransplantation and the influence of graft preservation time before reimplantation was considered. 1) The phospholipid composition of the grafted lobe is unchanged. 2) The incorporation of 32P orthophosphate in phosphatidylcholines is increased in the entire grafted lung (transplanted and ungrafted lobes).

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