Biomedical subjects

J Jacquot

Publications and source records attributed to J Jacquot.

44 records · Page 3Linked to original sources

PubMed1985

In vitro evidence that human airway lysozyme is cleaved and inactivated by Pseudomonas aeruginosa elastase and not by human leukocyte elastase.

The in vitro effects of Pseudomonas aeruginosa elastase (P. aeruginosa E) and of human leukocyte elastase on human airway lysozyme (HAL) were investigated. P. aeruginosa E inactivated and cleaved HAL, whereas human leukocyte elastase had no effect. Total inactivation of HAL by P. aeruginosa E was observed after 120 min of incubation at 37 degrees C, for an elastase-to-lysozyme molar ratio of 1:5. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of reaction mixtures containing HAL and P. aeruginosa E in an elastase-to-lysozyme molar ratio of 1:10 showed a progressive disappearance of the HAL band upon increasing the incubation time with P. aeruginosa E. Gel filtration chromatography indicated that HAL was cleaved into at least three peptide fragments. The cleavage of HAL by P. aeruginosa E was accompanied by parallel losses of its bacteriolytic activity and its immunoreactive property.

Bacterial Proteins↗

PubMed1985

Evidence that Pseudomonas aeruginosa elastase does not inactivate the bronchial inhibitor in the presence of leukocyte elastase. Studies with cystic fibrosis sputum and with pure proteins.

Pseudomonas aeruginosa elastase has recently been shown to inactivate bronchial inhibitor, the major leukoproteinase inhibitor of the bronchial tree. To test if this in vitro finding is relevant to pathology, we have measured the leukocyte elastase inhibitory capacity and the immunoreactive levels of bronchial inhibitor in the acidified and neutralized sputum specimens from 15 patients with cystic fibrosis, 11 of whom were infected by P. aeruginosa and 10 of whom exhibited free bacterial elastase activity. The percentage of functionally active bronchial inhibitor in these acid-treated sputum specimens (i.e., concentration of active inhibitor/concentration of immunoreactive inhibitor X 100) was found to be 125 +/- 17%. It was positively correlated with the free leukocyte elastase concentration (r = 0.77, p less than 0.001) but not with the free bacterial elastase concentration (r = 0.46, p greater than 0.05). Therefore, in an in vivo situation, P. aeruginosa elastase does not necessarily inactivate the bronchial inhibitor. Experiments using pure proteins show that the inactivation process does not take place when leukocyte and P. aeruginosa elastase are added simultaneously to the inhibitor. This suggests that the bronchial inhibitor reacts preferentially with leukocyte elastase and that in its complexed form it is shielded from the inactivating action of P. aeruginosa elastase. In addition, the inhibitor recovered from the acid-induced dissociation of the leukocyte elastase-inhibitor complexes, exhibits a substantially higher specific activity than does the native molecule. This explains why the average functional activity of the bronchial inhibitor is significantly higher than 100% in sputum samples from patients with cystic fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1985

Elasto-thixotropic properties of bronchial mucus and polymer analogs. I. Experimental results.

The non-newtonian viscous and elasto-thixotropic properties of native and lyophilized pathological bronchial mucus and of polymer solutions (3% and 6% PIB in decalin) used as mucus analogs were analyzed using a cone-plate Carri-Med rheometer and a Couette viscoelastometer that we have specifically developed for measuring the rheological properties of bronchial mucus in clinical practice. The master curves obtained for apparent viscosity under steady conditions as a function of shear rates (gamma: 2.6 X 10(-3) to 6.9 X 10(1) sec-1) were fairly similar, whatever the apparatus used. Under transient conditions, at low shear rate (gamma less than 1.4 sec-1), PIB and mucus exhibited a typical viscoelastic behavior: the shear stress increased slightly up to a steady-state value. At higher gamma, a transitory overshoot of sigma characteristic of the elastothixotropic systems appeared. Such a behavior can be interpreted as resulting from structural changes such as formation and rupture of the three-dimensional network present in bronchial mucus as in polymer solutions.

Bronchi↗

PubMed1983

Noncompetitive enzyme immunoassay for the measurement of bronchial inhibitor in biological fluids.

An enzyme-linked immunosorbent assay (ELISA) of bronchial inhibitor using rabbit antibronchial inhibitor antibody-coated polystyrene balls as the solid-phase antibody and peroxidase-labeled antibody as the conjugate is described. A crude antibody fraction is used for coating the solid phase. The assay can be run within 8 h and gives reproducible results in the range of 6 to 60 micrograms/l of bronchial inhibitor (mean within-run coefficient of variation, 7%). It can detect bronchial inhibitor concentrations as low as 2 micrograms/l (10(-10) M) and recovery of varying amounts of bronchial inhibitor added to bronchial liquids is greater than 90%. This enzyme immunoassay appears to be a convenient way to quantify bronchial inhibitor in biological fluids such as serum, sputum, or bronchoalveolar lavage fluid.

Antibody Specificity↗

PubMed1983

[Comparison of 2 extraction methods of immunoglobulins A and serum albumin in sputum].

The concentrations of immunoglobulins A (IgA) and serum albumin (SA) determined in sputum by electro-immunoassay have been compared after the extraction of proteins by two methods: 1) ion exchange chromatography and 2) mechanical agitation at high ionic strength. No significant difference of IgA is observed between the two methods. On the contrary, a very significant decrease in the concentration of SA is observed by the chromatographic extraction which is incomplete when pH - value of extract is lower than that of the isoelectric point of SA.

Chromatography, Ion Exchange↗

PubMed1981

Effect of terbutaline on mucociliary transport and sputum properties in chronic bronchitis.

A double-blind study with placebo control was carried out in 20 patients with chronic bronchitis to analyze the effect of oral terbutaline on mucociliary transport and sputum properties. Terbutaline (2.5 mg tablets) was given 3 times a day for 1 week. The clinical score, forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) significantly improved after treatment with terbutaline and confirmed the bronchodilating action of this drug. The mucociliary clearance measured with a radioactive aerosol tracer did not significantly differ after treatment with terbutaline and placebo although the initial site of aerosol deposition was similar in the two groups before and after treatment. The viscoelastic properties of sputum and their in vitro transport rate on the frog palate were not modified by terbutaline. The decrease in sputum volume and serum albumin concentration suggests a bronchial anti-inflammatory effect of this medication.

Bronchitis↗

PubMedDate not supplied

[Structure and secretory functions of the respiratory epithelium].

Airway secretions actively participate in respiratory epithelium protection. Apart from its main participation in transport of inhaled microorganisms and particles by mucociliary clearance, respiratory mucus also contributes to other protective purposes such as the control of airway humidification. Biochemical components found in secretions, such as mucins, lipids, antibacterial agents (secretory IgA, lysozyme, lactoferrin), antioxidant and antiprotease components, contribute significantly to the airway epithelium defense.

Cells, Cultured↗

PubMedDate not supplied

[Proteins of bronchial secretions in mucoviscidosis. Role of infection].

The protein composition of sputum collected by a protected method in 17 children with cystic fibrosis (CF) was analysed. The severity of the disease was assessed using the Shwachman score and the degree of bronchial superinfection was determined by a quantitative cyto-bacteriological study. The main proteins with antibacterial activity (IgA, IgG, IgM, lysozyme and lactoferrin) or reflecting the degree of bronchial inflammation (serumalbumin and alpha 1-antitrypsin) were determined by immunological methods. In the presence of severe superinfection (11 cases out of 17), the concentrations of antibacterial activity proteins are unchanged. On the other hand, the bronchial superinfection is accompanied by a marked local inflammation. In sputa, the increased concentrations of serum-derived proteins are closely correlated to the severity of the disease. This study confirms the importance of bronchial inflammation in CF.

Adolescent↗