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Biomedical subjects

J J Lafitte

Publications and source records attributed to J J Lafitte.

At least 19 recordsLinked to original sources
PubMed1995

Characterization of a sulfotransferase from human airways responsible for the 3-O-sulfation of terminal galactose in N-acetyllactosamine-containing mucin carbohydrate chains.

A galactose 3-O-sulfotransferase activity able to transfer a sulfate group from adenosine 3'-phosphate 5'-phosphosulfate to methyl galactosides or terminal N-acetyllactosamine-containing carbohydrate chains from human respiratory mucins was characterized in microsomal fractions prepared from human respiratory mucosa. The reaction products, methyl alpha- or beta-galactose 3-sulfate and three oligosaccharide alditols containing the sequence HSO3-3Gal beta 1-4GlcNAc beta 1-6GalNAc-itol were identified by high performance anion-exchange chromatography. Using methyl beta-galactoside as a substrate, the optimum activity was obtained with 0.1% Triton X-100, 30 mM NaF, 20 mM Mn2+, and 10 mM AMP in a 30 mM 2-(N-morpholino)ethanesulfonic acid buffer at pH 6.1. The apparent Km for methyl beta-galactoside and for adenosine 3'-phosphate 5'-phosphosulfate were observed at 0.69 x 10(-3) M and at 4 x 10(-6) M respectively. This sulfotransferase is different from that responsible for sulfatide synthesis.

Adenosine Monophosphate↗
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

Expression of human mucous proteinase inhibitor in respiratory tract: a study by in situ hybridization.

Human mucous proteinase inhibitor (MPI) is present in bronchial secretions, where it participates in the protection of lung structures against degradation by leukocyte elastase. The protein has been localized by immunohistochemical studies and immunogold labeling essentially in the serous cells of the submucosal glands and also in the surface epithelial cells of central and peripheral airways. However, until now no gene expression study has been performed at the tissue level. In this study, in situ hybridization was used to precisely study MPI mRNA expression in bronchial tissue sections with a specific radiolabeled oligonucleotide probe. By light microscopy, MPI gene expression was localized exclusively in the serous and seromucinous acini of the submucosal glands of large airways. The MPI gene was expressed in submucosal glands of normal and carcinomatous tissue sections, whereas it was not expressed in bronchial and bronchiolar surface epithelia.

Base Sequence↗
PubMed1995

High-dose and low-dose systemic corticosteroids are equally efficient in acute severe asthma.

The optimal amount of systemic corticosteroids to be used in acute severe asthma remains an unresolved issue. In this double-blind, randomized study we compared two doses of methylprednisolone (1 vs 6 mg.kg-1 q.d.) in asthmatics presenting with an acute severe asthma attack, unresponsive to an intensive beta 2-agonist regimen administered during a run-in period. Concurrent therapy, including oxygen, inhaled and intravenous salbutamol, and aminophylline was strictly standardized. The response was assessed by serial bedside spirometry. The primary outcome measurement was forced expiratory volume in one second (FEV1) (expressed as percentage of predicted values) at 24 and 44 h. The trial was designed in order to achieve a statistical power of 90%. Twenty three patients were included in the low-dose group and 24 in the high-dose group. Both groups were comparable in terms of demographic profiles, history of asthma, and severity of the current attack. Improvement in pulmonary function was similar in both groups. At 44 h, the mean (+/- SD) FEV1 values were 53 +/- 22 and 45 +/- 14% in the low and in the high-dose group respectively (NS). We conclude that high dose systemic corticosteroids offer no further benefit over low-doses in the treatment of severe acute asthma.

Acute Disease↗
PubMed1995

[Myeloma with intrathoracic tumor expression].

We report a case of a patient of 58 years old who suffered from a left apical opacity occurring in a context of deterioration in general health. Subsequent clinical developments were dominated by the ophthalmic disease and a frontal syndrome. The radiological work-up showed tumoral lesions which had developed from the first rib, from the structures at the base of the cranium and the frontal area and were associated with multiple lacunae of the cranial vault. There was evidence of hyperproteinaemia, and an IgG gamma monoclonal gammopathy, a significant medullary plasmocytosis with morphological anomalies of the plasmocytes leading to a diagnosis of myeloma with a plasmocytoma of the rib and the retro-orbital area. Thoracic disease associated with this pathology is common but mainly present as osteolytic lesions. The occurrence of intrathoracic plasma cell tumours is rarer as are orbital manifestations. In spite of treatment which can frequently lead to an objective response, the prognosis of this disorder remains gloomy.

Bone Neoplasms↗
PubMed1994

Determinants of response to immunosuppressive therapy in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) response to corticosteroids and cytotoxic medications appears to be the most important determinant of survival. The purpose of this retrospective study was to analyse the determinants of response to immunosuppressive therapy with prednisone alone, or prednisone and cyclophosphamide, in IPF. Twenty five consecutive patients were studied. Initial evaluation in untreated patients included clinical, biological and functional parameters. Sequential evaluation by pulmonary function tests (forced vital capacity (FVC) and transfer factor of the lungs for carbon monoxide (TLCO)) was performed at a 3 month interval. Response to therapy was defined as an improvement in FVC and/or TLCO of more than 10% after 12 months, with maintenance of this improvement for at least another 12 months. Twelve of the 25 patients were classified as responders. A symptomatic disease of less than 12 months duration before onset of therapy related to response. FVC was more impaired in the group of responders when the comparison was limited to patients with an FVC of less than 90%. Bronchoalveolar lavage cell counts were not significantly different between responders and non-responders. Assessment of pulmonary function after 3 months of treatment was predictive of maintenance of the response or of even further improvement. Patients with improved FVC after 3 months of therapy had a significantly shorter symptomatic disease before onset of treatment (7.6 +/- 7.1 vs 20.2 +/- 18.6 months). A beneficial effect of addition of cyclophosphamide was observed only in patients who demonstrated an early but short-lived improvement to steroids. Adverse reactions of immunosuppressive therapy were noticed in 10 patients, and required discontinuation of treatment in six of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchoalveolar Lavage Fluid↗
PubMed1992

The binding of amikacin to macromolecules from the sputum of patients suffering from respiratory diseases.

Antibiotics bind to whole cystic fibrosis sputum, however, the composition of sputum varies from one patient to another, making the interpretation of binding studies difficult. This problem has been examined by standardizing the macromolecule concentration of sputum from 13 patients suffering from cystic fibrosis, chronic bronchitis or bronchiectasis and adding amikacin to the sputum components. Also binding to fractions of sputum was studied before and after treatment with DNase or chondroitinase. These studies indicated that the degree of amikacin binding is dependent on the DNA concentration and the presence of acidic mucins.

Amikacin↗
PubMed1992

[Adenocarcinomatous pleural lesion associated with hypoglycemia].

We report the case of a patient suffering from a glandular pleural lesion. The evolution of the disease was punctuated by periods of hypoglycaemia, which caused a coma. There was no clinically evident explanation for these hypoglycaemic episodes. Investigations revealed adrenal failure, but this adrenal failure was unrelated to the neoplastic process in the patient. This case is a reminder that the cause of hypoglycaemia associated with tumours can really have a paraneoplastic origin and justifies an in depth study to achieve an aetiological diagnosis.

Adenocarcinoma↗
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

An attempt to evaluate lung aggression in monkey silicosis: hydrolases, peroxidase and antiproteases activities in serial bronchoalveolar lavages.

Exposure to silica can induce fibrosis and/or emphysema. Various factors such as proteases, other hydrolases and oxidants may be involved in the destruction of lung parenchyma. On the other hand, antiproteases play an important role in the protection of lung parenchyma against the action of proteases. We have developed an animal model of silicosis in monkey Macacus cynomolgus and followed these factors by bronchoalveolar lavage (BAL). We have studied glycosidases activities, elastase-like activity, immunoreactive alpha 1-protease inhibitor (alpha 1PI), neutrophil elastase inhibitory capacity (NEIC) and myeloperoxidase. Bronchoalveolar cells in serial BAL were also studied. Six monkeys were exposed to quartz aerosols (100 mg.m-3) for 18 wks. They were followed until they developed X-ray changes, which occurred between 21-64 wks after the end of the dust exposure. Cellular "silicotic nodules" were observed in lung biopsies. A control animal underwent serial BAL. Changes were seen in the differential cell count. The release of superoxide anion by bronchoalveolar cells obtained during the experiment was increased. Separation on a gradient of Percoll showed the presence of young macrophages, which exhibited enhanced release of superoxide anion as compared to the totality of bronchoalveolar cells. The biochemical analysis of BAL fluids obtained during and after the period of dust exposure showed an increase in glycosidases, alpha 1PI and NEIC. Some free elastase-like activity was simultaneously detected in BAL fluids from exposed animals but not from the control. This elastase-like activity was very low compared to NEIC. The increase in enzymatic and antiprotease activities occurred at different points in time for each animal, suggesting large differences in individual responses to dust, but occurred before the chest X-ray abnormalities.

Acetylglucosaminidase↗