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Biomedical subjects

C Galabert

Publications and source records attributed to C Galabert.

At least 19 recordsLinked to original sources
PubMed1999

The sialylation of bronchial mucins secreted by patients suffering from cystic fibrosis or from chronic bronchitis is related to the severity of airway infection.

Bronchial mucins were purified from the sputum of 14 patients suffering from cystic fibrosis and 24 patients suffering from chronic bronchitis, using two CsBr density-gradient centrifugations. The presence of DNA in each secretion was used as an index to estimate the severity of infection and allowed to subdivide the mucins into four groups corresponding to infected or noninfected patients with cystic fibrosis, and to infected or noninfected patients with chronic bronchitis. All infected patients suffering from cystic fibrosis were colonized by Pseudomonas aeruginosa. As already observed, the mucins from the patients with cystic fibrosis had a higher sulfate content than the mucins from the patients with chronic bronchitis. However, there was a striking increase in the sialic acid content of the mucins secreted by severely infected patients as compared to noninfected patients. Thirty-six bronchial mucins out of 38 contained the sialyl-Lewis x epitope which was even expressed by subjects phenotyped as Lewis negative, indicating that at least one alpha1,3 fucosyltransferase different from the Lewis enzyme was involved in the biosynthesis of this epitope. Finally, the sialyl-Lewis x determinant was also overexpressed in the mucins from severely infected patients. Altogether these differences in the glycosylation process of mucins from infected and noninfected patients suggest that bacterial infection influences the expression of sialyltransferases and alpha1,3 fucosyltransferases in the human bronchial mucosa.

Bronchi↗
PubMed1999

[Carotenoids: 2. Diseases and supplementation studies].

Inverse correlations have been found in most studies on the relationship between dietary intake and plasma concentrations of carotenoids on one side and degenerative diseases such as cancer and cardiovascular diseases on the other side. Protective effects of carotenoids have been found for pathologies of the retina and the skin. Concentrations of these molecules in blood are lower in digestive pathologies and HIV. Short- and long-term toxicity of carotenoids was found to be low. In combination with the beneficial effects found for diets rich in carotenoids, this has initiated trials with relatively high doses of carotenoid supplements. In the study in Linxian (China) in a rural population with poor nutritional status, supplementation with beta-carotene, zinc, selenium and vitamin E lowered total mortality and mortality from stomach cancer. Other studies (ATBC, Caret.) on well-fed subjects did not show beneficial effects on mortality from cancer and cardiovascular diseases. On the contrary, higher mortality and lung cancer incidence was found in supplemented subjects that were also exposed to asbestos and cigarette smoke. In these studies, doses of supplemental beta-carotene were high and varied from 20 to 50 mg/day. One still ongoing study, called Suvimax, doses subjects for eight years with a cocktail of vitamins and minerals including 6 mg per day of beta-carotene. This supplementation with physiologically seen more "normal" doses might give clarity on the question if beta-carotene is the protective factor in fruits and vegetables.

Anticarcinogenic Agents↗
PubMed1998

Improvement of cystic fibrosis airway mucus transportability by recombinant human DNase is related to changes in phospholipid profile.

The aim of this study was to test whether changes in mucus surface properties by rhDNase treatment could be related to an increased recovery of phospholipids. Purulent sputa from 18 patients with cystic fibrosis (CF) were incubated with either rhDNase (4 microg/ml) or control excipient. The incubation of mucus samples with rhDNase induced a significant increase (p < 0.002) in the sol phase proportion (33.7 +/- 24.0%) compared with that obtained with excipient (12.6 +/- 12.4%). Phospholipids were recovered in significantly (p < 0.05) greater amounts from both mucus gel and sol phases after incubation with rhDNase. The phosphatidylglycerol content of mucus sol phase was significantly increased by rhDNase (p < 0.03), as well as the mucus gel phase surface properties and transport by ciliary activity and by cough (p < 0.05). The improvement of mucus gel surface properties and transport capacity by ciliary activity were significantly related to the increased recovery of phosphatidylglycerol (r = -0.74, p < 0.03 and r = 0.94, p < 0.05, respectively). These results suggest that rhDNase is able to increase the free water content and alter the phospholipid profile of mucus, with a related improvement in CF mucus transportability.

Adult↗
PubMed1995

Production of elastase, exotoxin A, and alkaline protease in sputa during pulmonary exacerbation of cystic fibrosis in patients chronically infected by Pseudomonas aeruginosa.

Secretion of Pseudomonas aeruginosa elastase, exotoxin A, and alkaline protease in sputum during bronchopulmonary exacerbations was examined in 18 cystic fibrosis patients chronically infected with this microorganism. The patients were studied during one or several exacerbation periods necessitating hospitalizations of 12 to 20 days. In all cases, P. aeruginosa was present in bronchial secretions at admission and was not eradicated after treatment. The P. aeruginosa density decreased significantly after antibiotic therapy but remained greater than 10(6) CFU/g of sputum in most cases. Significant amounts of P. aeruginosa exoproteins were measured in total homogenized bronchial secretions by immunoenzymatic assays. The detection of higher levels of exoproteins at admission, the significant decrease after treatment, and the absence of exoproteins during intercrisis phases constituted arguments for a renewal of virulence of P. aeruginosa during exacerbations. Nevertheless, the concomitant changes in bacteria load and the triggering of the inflammatory process and immune complex formation could also contribute to pulmonary exacerbations.

ADP Ribose Transferases↗
PubMed1994

Immunoenzymometric assays for alkaline protease and exotoxin A from Pseudomonas aeruginosa: development and use in detecting exoproteins in clinical isolates from patients with cystic fibrosis.

Using immunoenzymometric assays, the production of elastase, alkaline protease and exotoxin A was determined in culture supernatants of 35 strains of Pseudomonas aeruginosa isolated from patients suffering from cystic fibrosis. The assays were simple, specific, sensitive and reproducible, and permitted the determination of low levels of exoproteins. A large strain variability of exoprotein production was found. Most of the strains secreted all three exoproteins, but six out of the 35 strains (17%) did not secrete at least one of the three (< 0.3 microgram/l). A significant correlation was observed between elastase and exotoxin A productions (r = 0.697, p < 0.001).

ADP Ribose Transferases↗
PubMed1994

[Production of elastase, exotoxin A and alkaline protease during bronchopulmonary exacerbations in patients with mucoviscidosis chronically infected by Pseudomonas aeruginosa].

The authors have studied the production of exoproteins by Pseudomonas aeruginosa in the sputa of 18 patients suffering from cystic fibrosis, during 29 bronchopulmonary exacerbations and also after the recovery of a stable state. Significant levels of exoproteins were detected but with a large heterogenity of intra and inter individual variations. A significant decrease in the production of the three exoproteins was found after twelve days of antibiotherapy, without any correlation between exoprotein levels and colony forming units in the sputa. During the intercrisis phase, exoproteins levels were practically undetectable. These facts and the good correlation between clinical symptoms support the hypothesis of a renewal of virulence of Pseudomonas aeruginosa during these periods of bronchopulmonary exacerbation in cystic fibrosis.

Adolescent↗
PubMed1993

Direct double antibody sandwich immunoassay for Pseudomonas aeruginosa elastase.

A direct sandwich enzyme immunoassay was developed in order to quantify Pseudomonas aeruginosa elastase. As a solid phase the wells of a microtitre plate were coated with specific IgG and horseradish peroxidase labelled IgG was used as the second antibody. The detection limit of the assay was 0.26 ng/ml and a good agreement was found with elastolytic activity determined using elastin-Congo red. This assay was simple, specific, sensitive and reproducible, and permits the determination of low levels of elastase.

Cystic Fibrosis↗
PubMed1993

Altered carbohydrate composition of salivary mucins from patients with cystic fibrosis and the adhesion of Pseudomonas aeruginosa.

We compared the chemical composition of salivary mucin glycopeptides from cystic fibrosis (CF) and from non-CF subjects and the adhesion of Pseudomonas aeruginosa to these different salivary glycopeptides. Three pools of CF saliva, four pools of non-CF saliva, one individual CF saliva, and one individual non-CF saliva were studied. The soluble fraction of the saliva was treated with pronase, and gel filtration was performed to obtain high and low molecular mass salivary mucin glycopeptides. The yield of total glycopeptides was significantly higher from CF than from non-CF saliva. Furthermore, the chemical composition revealed a significantly higher sialic acid content in CF than in non-CF mucin glycopeptides, and higher sulfate and fucose content in CF than in non-CF high molecular mass glycopeptides. We studied the adhesion of a nonmucoid strain of P. aeruginosa (1244), its nonpiliated isogenic derivative, and a mucoid strain (M35) to salivary mucin glycopeptides from patients with CF and from non-CF subjects. The three strains bound significantly more to the CF salivary glycopeptides than to the corresponding non-CF salivary glycopeptides. The nonpiliated isogenic mutant of P. aeruginosa 1244 also bound to CF salivary glycopeptides, suggesting that the adhesion of P. aeruginosa could involve nonpilus adhesions. Furthermore, neuraminidase treatment of CF glycopeptides decreased the adhesion of P. aeruginosa 1244. Altogether these results suggested that differences in mucins may in part explain the specificity of P. aeruginosa for CF.

Bacterial Adhesion↗
PubMed1992

Phospholipid composition and surface-active properties of tracheobronchial secretions from patients with cystic fibrosis and chronic obstructive pulmonary diseases.

Among the various components of tracheobronchial secretions, lipids and particularly phospholipids have been shown to influence rheological properties of airway secretions in patients with cystic fibrosis. We studied the phospholipid composition of tracheobronchial secretions, collected from patients suffering from cystic fibrosis (CF) and other chronic obstructive pulmonary diseases (COPD), and we analyzed the possible relationship between the phospholipid profile and the wettability of tracheobronchial secretions evaluated by the measurement of contact angle. Although total phospholipid content and contact angle of tracheobronchial secretions were significantly increased (P less than 0.01) in CF compared to COPD, no significant relationship existed between these two parameters. The concentrations of the different phospholipid subclasses were not homogeneously modified according to the origin of the secretions. Compared to COPD secretions, the CF secretions were characterized by a significant (P less than 0.001) increase in rigidifying fractions such as sphingomyelin and phosphatidylserine/phosphatidylinositol and a significant (P less than 0.001) decrease in surface-active fractions, such as phosphatidylcholine and phosphatidylglycerol (PG) (P less than 0.001). In the two groups, the surface-active phospholipid fraction, PG, was negatively correlated to the contact angle of tracheobronchial secretions. These results suggest that a decrease in PG content in CF secretions may be one factor responsible for an increase in their adhesivity to the respiratory mucosa, and, consequently, for mucus stasis and severity of bronchial obstruction in cystic fibrosis.

Adolescent↗
PubMed1992

Functions of proteins and lipids in airway secretions.

Proteins and lipids synthesized by airway secretory cells or transudated are active components in the protection of respiratory epithelium. Proteins and ions are involved in the control of mucus hydration. Secretory proteins, such as secretory immunoglobulin A (IgA), transferrin and lysozyme, participate in the airway antibacterial defence. Other biochemical components found in secretions, such as anti-inflammatory and antioxidant agents as well as antiproteases, contribute significantly to the protection of the underlying epithelium.

Bronchi↗
PubMed1991

Role of phospholipid lining on respiratory mucus clearance by cough.

Phospholipid lining, present at the respiratory mucus-mucosa interface, may have an important role in the protective function of the airways by its abhesive properties and may also facilitate mucus transport. To mimic respiratory mucus-mucosa interface, monolayers of three different forms of phosphatidylglycerol (PG) have been deposited on glass slides by the Langmuir-Blodgett technique. Mucus adhesion and clearance by cough of mucus on these PG-coated or noncoated surfaces have been analyzed and compared, using frog respiratory mucus as "normal" mucus. Among the three PG types studied, the phosphatidylglycerol distearoyl, which is the phospholipid with the longest saturated fatty acid chain, was found to significantly improve the mucus cough clearance by decreasing the mucus work of adhesion compared with the noncoated surfaces. On the other hand, phosphatidylglycerol dipalmitoyl did not improve mucus cough clearance although it decreased mucus adhesion, and phosphatidylglycerol dioleyl did not improve either mucus cough clearance or mucus adhesion.

Animals↗
PubMed1991

Chondroitin sulfate in sputum from patients with cystic fibrosis and chronic bronchitis.

In order to ascertain whether or not the presence of glycosaminoglycans in sputa of patients suffering from chronic bronchial disorders was related to tracheobronchial infection, an electrophoretic procedure was set up. The different acidic macromolecular components of sputum, namely nucleic acids, glycosaminoglycans, and bronchial glycopeptides could be identified in proteolyzed sputum using agarose electrophoresis before and after the action of different enzymes: nucleases, chondroitinases, hyaluronidase and heparinase. This procedure was used to analyze 13 sputum samples from patients suffering from cystic fibrosis (CF) and 12 sputum samples from patients suffering from chronic bronchitis. Chondroitin sulfate was identified in 11 infected sputum samples from patients with CF and also in the noninfected sputum from a patient with chronic bronchitis. These data suggest a relationship between the presence of chondroitin sulfate proteoglycans in sputum and severe tracheobronchial infection in CF.

Adolescent↗
PubMed1991

Identification of phospholipids in secretory granules of human submucosal gland respiratory cells.

Although it has been shown that tracheal epithelial cells in culture synthesize and secrete phospholipids, no direct evidence for in situ phospholipid storage in human respiratory secretory epithelial cells has been demonstrated. We used a high-resolution cytochemical enzyme-gold technique to identify and precisely localize phospholipids in human submucosal gland secretory cells. In addition, lysozyme, a specific serous cell marker, was identified using the biotinstreptavidin gold technique with lysozyme antiserum. This double labeling of phospholipids and lysozyme was performed using gold particles of diameters 15 nm and 5 nm, respectively. Quantitation of phospholipid labeling was performed on an image analyzer. Phospholipids were identified in serous granules (8.87 +/- 2.21 gold particles/microns 2) in a significantly (p less than 0.05) higher density than in mucous granules (5.57 +/- 3.07 gold particles/microns 2). These results support the hypothesis that submucosal human airway serous and mucous secretory cells produce phospholipids which may be secreted in the airway lumen.

Bronchoalveolar Lavage Fluid↗
PubMed1989

Plasma and serum lactoferrin levels in cystic fibrosis. Relationship with the presence of cystic fibrosis protein.

Plasma lactoferrin concentrations were measured in blood of cystic fibrosis patients, heterozygotes and controls using a specific and sensitive enzyme immunoassay. 67 plasmas were studied (26 controls, 23 heterozygotes, 18 cystic fibrosis patients) and the results showed a statistically significant increase (p less than 0.05) of the level of plasma lactoferrin in cystic fibrosis patients (265 +/- 224 micrograms/l) compared to controls (168 +/- 100 micrograms/l) and heterozygotes (150 +/- 72 micrograms/l). Since it is well established that plasma lactoferrin level could be influenced by the number of neutrophils, a second set of experiments was performed on 20 cystic fibrosis patients on whom leukocyte counts were also made. When the 15 plasmas with normal neutrophils (in the range 2 to 6 giga/l) were considered, the mean lactoferrin level was 318 +/- 116 micrograms/l, still far above the normal values. For serum, a similar significant increase of lactoferrin concentration was observed in 33 cystic fibrosis patients (610 +/- 551 micrograms/l) compared to the values observed for 25 controls (237 +/- 155 micrograms/l) and 37 heterozygotes (272 +/- 231 micrograms/l). Cystic fibrosis protein (CFP) was identified in the same sera by isoelectric focusing and the intensity of the band was closely related to the increase of lactoferrin concentration in cystic fibrosis patients. In contrast, no difference in serum lactoferrin concentrations was observed between heterozygotes with or without CFP, indicating that the increased CFP concentration cannot be due only to altered granulocyte function.

Blood Proteins↗
PubMed1987

Correlation between the cystic fibrosis protein detected by isoelectric focusing and a protein of 12 kDa detected by SDS-polyacrylamide gel electrophoresis.

We have studied both by isoelectric focusing and polyacrylamide gel electrophoresis in the presence of SDS, sera of individuals homozygous (25) and heterozygous (26) for cystic fibrosis and compared them to controls (13). As in our first study [1], the protein with a pI value of 8.4 called 'cystic fibrosis protein' or CFP, was found in about 70% of homozygous and carriers and in 15% of controls. When the same sera were analysed by polyacrylamide gel electrophoresis in the presence of SDS and after staining with Coomassie Blue, an additional protein with a molecular weight close to 12,000 (P12) was present in most of the sera containing CFP, suggesting a close relationship between the two proteins. By increasing the sensitivity of staining by using silver nitrate, P12 was detected with variable intensity in almost all sera of homozygotes and heterozygotes and at the level of traces in all normal sera. These data suggest that P12, like CFP, would be a normal serum protein quantitatively increased in affected subjects.

Adult↗
PubMed1987

Relationships between the lipid content and the rheological properties of airway secretions in cystic fibrosis.

The lipid composition and rheological properties of expectorated airway secretions have been analyzed in 16 patients with cystic fibrosis (CF), separated into two groups according to whether their secretions were superinfected or not. The total lipid content was higher in the superinfected CF secretions. The content in cholesterol and GL1, GL3 and GL4 glycosphingolipid fractions were significantly higher in the superinfected in comparison to the non-superinfected group. The viscosity was two-fold higher in the CF superinfected group. A significant correlation (r = 0.72, p less than 0.01) was observed between the apparent viscosity and the total lipid content of CF secretions. Cholesterol, glycosphingolipids and sphingomyelin were the lipid components which were the most closely and positively correlated to the viscosity. On the opposite, phosphoglycerol was negatively correlated (r = -0.72, p less than 0.05) to the viscoelastic properties of CF airway secretions.

Adolescent↗