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Biomedical subjects

D Lauque

Publications and source records attributed to D Lauque.

At least 37 records · Page 2Linked to original sources

Self-expandable prostheses in the tracheobronchial tree.

Under endoscopic and radiologic control, two types of self-expandable metal prostheses were implanted in tracheobronchial lesions to help reestablish airway caliber. Thirty-nine metal stent prostheses (6-20 mm in diameter) and 35 Gianturco stents (30 mm in diameter) were used in 55 adult patients with 62 lesions of the trachea (n = 33) or bronchi (n = 29). All lesions except one were endoscopically confirmed to be noninflammatory. Immediately after implantation, radiologic and endoscopic studies verified reestablishment of a satisfactory airway diameter in all patients. At a mean follow-up of 10.35 (range, 3-27) months, improvement in the respiratory status of 49 of the 55 patients (89%) was maintained and tolerance of the device was excellent. For the Wallstent endoprosthesis, the six complications observed at endoscopy were successfully treated. The Gianturco stent, however, led to a high rate of complications: 30% of cases had migration and/or rupture of the metallic mesh, potentially leading to obstruction or wall perforation; one case of respiratory distress was fatal. This procedure offers rapid epithelialization and incorporation of the device into the tracheobronchial wall.

Adult↗

Primary pulmonary lymphomas. A clinical study of 70 cases in nonimmunocompromised patients.

We studied 70 patients with biopsy-proven pulmonary non-Hodgkin's lymphomas without extrathoracic involvement or mediastinal adenopathy to determine the clinical, imaging, and endoscopic features of this condition in a homogeneous series. In low-grade (LG) lymphomas, symptoms were cough, dyspnea, chest pain, hemoptysis. Imaging features consisted of localized alveolar opacities, infiltrative diffuse opacities, atelectasis, and pleural effusions. Inflammatory changes of the mucosa were present in some patients, leading to bronchial stenosis in 7; biopsies showed lymphomatous infiltration in 12. Prognosis of LG lymphomas was excellent, with 93.6 percent survival at five years. High-grade lymphomas differed from LG lymphomas principally by a more aggressive course and a worse survival. Inflammatory changes occurred in seven of nine cases leading to stenosis in two, and biopsies showed lymphomatous involvement in five. The profile of primary pulmonary lymphomas in this study could help clinicians consider this condition and prompt them to evaluate new diagnostic tools.

Adult↗

[Microscopic polyarteritis].

Microscopic polyarteritis is an idiopathic necrotising vascularitis of the small vessels. Manifestations include diffuse alveolar haemorrhage, segmentary necrotising glomerulonephritis, and a cutaneous, articular, neurological or digestive vascularitis. The absence of a histological granulomas and medium calibre vessel involvement distinguishes Wegener's syndrome from polyarteritis nodulosa. The diagnosis is facilitated when anti-neutrophil cytoplasm antibodies are found in the serum. These auto-antibodies are suspected to be the cause based on clinical and experimental data, although this aetiology has not been confirmed. Corticosteroids, immunosuppressors and plasmapheresis can improve the prognosis of this severe and evolving affection which may be fatal.

Adrenal Cortex Hormones↗

[Alveolar opacities and busulfan pneumonia].

A case of toxic pneumonia due to busulfan is reported in a man aged 65 treated for three years with busulfan for chronic myeloid leukaemia. He was admitted to hospital for dyspnoea, cough, fever and presented with crepitations, dense alveolar opacities, and a restrictive ventilatory defect. Trans-bronchial biopsy showed a filling of the alveoli by fibroblastic tissue, as well as voluminous dystrophic pneumocytes. Four months later in spite of steroid therapy the clinical state and respiratory function were worse. The alveolar opacities have regressed but some diffuse interstitial opacities had appeared. This new case is a reminder that the appearance of alveolar opacities in a patient treated with busulfan should raise the possibility of a toxic pneumonitis to busulfan in the differential diagnosis. This observation also underlines the role of the initial endo-alveolar fibrosis in the ultimate development of interstitial fibrosis.

Aged↗

Cotton condensed tannin: a potent modulator of alveolar macrophage host-defense function.

Alveolar macrophages are the resident airway cells primarily responsible for the protection of the lungs against inhaled toxins and other biologically active material. A number of functional capabilities constitute their host-defense function. They can phagocytize and inactivate foreign material by production of reactive oxygen intermediates or the action of hydrolytic enzymes. In the absence of phagocytosis, macrophages can secrete reactive oxygen intermediates or enzymes that inactivate extracellular biologically active material. They also can secrete metabolites of arachidonic acid and other cytokines that contribute to the inflammatory response of the lungs. Macrophages also secrete a variety of peptide and lipid chemotactic factors that lead to the recruitment of other inflammatory cells into the airways. The condensed tannins, which constitute a significant percentage of the water soluble compounds present in respirable cotton mill dust, dramatically alter the host-defense function of alveolar macrophages in vitro. Tannin inhibits both phagocytosis and production of reactive oxidants in a dose-dependent manner with EC50's of 16 micrograms/mL and 3 micrograms/mL, respectively. This inhibition dramatically decreases the ability of resident alveolar macrophages to clear and detoxify potentially harmful inhaled particles. However, at similar concentrations, tannin stimulates the dose-dependent secretion (EC50 = 15 micrograms/mL) of a low molecular weight lipid neutrophil chemotactic factor that could result in an inflammatory reaction with the recruitment of neutrophils into the lungs. At slightly higher concentrations, tannin promotes the dose-dependent release of arachidonic acid from the macrophage membranes (EC50 = 65 micrograms/mL), which could also contribute to the local inflammatory reaction. Finally, tannin also causes secretion of the cytokine, interleukin-1, from the monocyte precursors of macrophages with an EC50 of 32 micrograms/mL. Interleukin-1 has been implicated as one of the causative agents in the development of fever.

Animals↗

Signal transducing mechanisms in human platelets stimulated by cotton bract tannin.

Cotton bract tannin is a potent stimulus for platelet aggregation and secretion. Tannin has been shown to stimulate the phosphorylation of two 19-kD and 47-kD cytosolic proteins in platelets, but earlier steps in signal transducing mechanisms of platelet activation are unknown. In this study, measurements of 32P-labeled phospholipids, 14C-labeled arachidonic acid, and levels of intracellular free calcium (Ca2+) were performed before and after the addition of thrombin (1 U/ml) or various concentrations of tannin to human platelets. The results showed that tannin induced a dose-dependent synthesis of phosphatidic acid, an early and transient hydrolysis of phosphatidylinositol monophosphate and bisphosphate, a transient synthesis of diacylglycerol, and a release of arachidonic acid metabolites. The kinetics of phosphatidic acid, diacylglycerol, and arachidonic acid metabolite synthesis were similar after platelet stimulation by tannin (75 micrograms/ml) or thrombin. Tannin also induced a reversible rise of intracellular Ca2+ due to a mobilization of the internal stores and an influx of extracellular Ca2+. These results suggest that cotton bract tannin, as thrombin, activates human platelets by phospholipase C and A2 activations, release of diacylglycerol, and mobilization of intracellular free Ca2+.

Arachidonic Acids↗

[Evaluation after 2 years of substitutive treatment of PiZZ emphysema with alpha-1 antitrypsin. 9 cases].

Homozygous PiZZ individuals with a serum deficiency due to a defect in the secretion of the alpha 1-antitrypsin protein are at risk of developing severe panlobular emphysema. Tobacco smokers are particularly exposed to the disease which begins at an earlier age. Treatment by substitutive therapy with alpha 1-antitrypsin concentrates seems to be the only possibility. A two years' clinical trial was performed in 9 PiZZ patients, with more than 1,500 infusions being administered weekly. Serum AAT levels were used as guidelines to follow biochemical changes in the protease-antiprotease balance. From 0.16 g/l initially, the AAT level rose to 0.57 g/l after 7 months. No adverse reaction was observed during the trial; the concentrated protein was well accepted, ant the antielastase activity of the protein recovered after injection was equivalent to the activity injected. An attempt to administer the infusions monthly was stopped when we observed a dramatic decrease of the serum AAT level. Clinically, stabilization of the symptoms was noted. No degradation was observed in the patients who took part in the trial, even if no real improvement was detected.

Adult↗

Bronchoalveolar lavage in liquid paraffin pneumonitis.

We evaluated cells and lipids recovered in the bronchoalveolar lavage fluid from seven patients with liquid paraffin pneumonitis. For each patient, the BALF was whitish with oil droplets on the surface. Alveolar macrophages contained numerous, large vacuoles that did not react with May-Grunwald-Giemsa, Papanicolaou, or periodic acid-Schiff but were stained in black with Sudan B, orange with Sudan III and red with oil Red O. Liquid paraffin was identified on thin layer chromatography of BALF-extracted lipids as a very hydrophobic compound migrating on the solvent front as control liquid paraffin. This abnormal spot was definitely identified as liquid paraffin by infrared spectroscopy and gas liquid chromatography for the first patient. The number and percentage of AMs were largely decreased in the BALF of each patient, whereas the number of neutrophils, eosinophils and lymphocytes was increased. These findings suggest that this cell-mediated inflammatory response plays a role in the development of interstitial fibrosis at late stages of liquid paraffin pneumonitis.

Aged↗

[Natural history of bronchiolo-alveolar cancer. Apropos of 38 cases].

Thirty-eight cases of bronchioloalveolar carcinoma were selected on anatomico-pathological criteria and analysed both radioclinically and histologically. At histology, this type of carcinoma is characterized chiefly by the growth of malignant cells along the alveolar walls. Cytology, which determines the nature of these cells (pneumocyte II or Clara cell), is not specific but remains important as regards phylogenesis. The course of bronchioloalveolar carcinoma gives a better understanding of its mode of propagation. Actuarial curves show that all patients with a diffuse carcinoma die very rapidly, whereas the survival rate of those who have localized lesions is 60% at 5 years. Moreover, the time required for dissemination to take place is long in assessable cases. This means that the condition should be diagnosed at an early stage on the presence of crepitant rales, on their air bronchogram at CT and on transparietal needle biopsy under CT. The chances are that early excision will result in cure.

Actuarial Analysis↗

[Pulmonary calcinosis].

Interstitial pulmonary calcinosis was discovered after finding hypercalcaemia in a man of 56 who had been treated for several months with Hydrochlorthiazide. This was a secondary hyperparathyroidism due to the formation of parathyroid adenomatous cysts. This illness had been quiescent until then and was probably revealed as a result of the hydrochlorthiazide therapy.

Calcinosis↗

[Thoracic puncture guided by x-ray computed tomography. Apropos of 125 cases].

A series of 125 CT-guided thoracic punctures performed over a 20-month period is reported. The only complications were pneumothorax in 14 cases, 5 of which were drained, and 1 case of hemomediastinum. For the diagnosis of malignancy the sensitivity of the method was 82%, its specificity 100% and its effectiveness 74%. The level of sensitivity rose to 86% in the last 90 cases. This method is an additional contribution to exploration of the lungs. In trained hands it gives rise to few complications and should result in a histological diagnosis in a large number of cases.

Adult↗

Effect of oral N-acetylcysteine on mucus clearance.

Oral N-acetylcysteine has been advocated as a mucolytic agent for use in chronic bronchitis. We have investigated the effects of regular use of this drug at a dose of 200 mg thrice daily for 4 weeks in nine patients with chronic bronchitis on lung function, lung mucociliary clearance and sputum viscosity in a controlled, double-blind, crossover study. No significant differences were found in lung function, mucociliary clearance curves or sputum viscosity following treatment with N-acetylcysteine compared to control or placebo measurements.

Acetylcysteine↗