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Biomedical subjects

B Wallaert

Publications and source records attributed to B Wallaert.

At least 145 records · Page 8Linked to original sources
PubMed1996

CD28 expression is increased in venom allergic patients but is not modified by specific immunotherapy.

BACKGROUND: Recognition of antigen bound to the major histocompatibility complex by the T cell receptor is insufficient to lead to T cell proliferation and effector function, which require co-stimulatory signals, such as those resulting from the interaction of CD28 expressed on T lymphocytes and CD80/CD86 expressed on APCs. Lack of interaction between these accessory molecules during antigen stimulation leads to a state of antigen-specific lymphocyte unresponsiveness. Previous studies have shown that rush venom immunotherapy decreases venom-specific T cell proliferation very early after the initiation of the rush. OBJECTIVE: In order to see whether this hyporeactivity was associated with a down regulation of accessory molecules, we studied CD28 surface expression on T lymphocytes from 10 non-atopic controls and from 10 non-atopic patients undergoing rush venom immunotherapy. METHODS: Peripheral blood samples were collected before the rush (day 0), at the end of the rush (day 1), at day 15 and at day 45. CD28 expression was analysed using flow cytometry with double labelling of the CD4+ and CD8+ lymphocyte subpopulations. RESULTS: At baseline CD28 was expressed at a higher level on T lymphocytes from allergic patients than from control subjects (P < 0.04) and in particular on the CD8 subset (P < 0.01), reflecting a decrease in the suppressive CD8+CD28- subpopulation. No changes were found in the percentages of total CD28+ T cells, CD4+CD28+ or CD8+CD28+ cells at the different time points after the initiation of of immunotherapy. CONCLUSION: These results suggest that the CD28 pathway is probably involved in the development of allergic reactions, but at least at the phenotypic level, CD28 expression remained unchanged after rush venom immunotherapy.

Adult↗
PubMed1996

[Paraneoplastic superior vena cava thrombosis disclosing an ovarian tumor].

We report the case of a patient who was admitted in hospital for evaluation of a superior vena cava thrombosis. The patient exhibited an activated protein C resistance due to an arginine-506 mutation in factor V. Thoracic CT-scan showed a non-compressive complete superior vena cava thrombosis. Other investigations revealed a pleural effusion associated with an ovarian tumor. Pathological data of pleural biopsies showed a papillar carcinoma. Ovarian neoplasia revealed by a paraneoplasic syndrome was diagnosed. Treatment associated cyclophosphamide and carboplatin with anti-K-vitamin was administrated, with a complete remission and disappearance of superior vena cava thrombosis at 27 months of evolution. At this date, we observed a local pelvis recurrence which was treated with paclitaxel associated with surgery.

Anticoagulants↗
PubMed1995

Immunoreactivity for interleukin 3 and 5 and granulocyte/macrophage colony-stimulating factor of intestinal mucosa in bronchial asthma.

T lymphocytes and eosinophils are important components of the inflammatory cell infiltrate in bronchial mucosa in asthma. Because activated lymphocytes migrate through the thoracic duct and the general circulation to remote glandular and mucosal sites, we initiated this study to evaluate pathological abnormalities and immunoreactivity for interleukin (IL) 3, IL-5, and granulocyte/macrophage colony-stimulating factor (GM-CSF) of intestinal mucosa in bronchial asthma. 15 asthmatic patients, 8 nonasthmatic patients with chronic obstructive pulmonary disease, 6 atopic nonasthmatic healthy controls, and 6 nonatopic healthy controls were studied. Duodenal biopsies were performed by endoscopy. A significantly increased number of intraepithelial lymphocytes and eosinophils and a significant accumulation of mononuclear cells (lymphocytes and mast cells) and eosinophils in the lamina propria were detected in asthmatics and atopic controls. Immunostaining with antibodies directed against IL-3, IL-5, and GM-CSF was positive in asthmatics and atopic controls, whereas no staining was observed in nonatopic controls and chronic obstructive pulmonary disease. Combined ultrastructural study and immunogold labeling demonstrated that IL-3, IL-5, and GM-CSF were localized in eosinophils and mast cells. Although devoid of gastrointestinal symptoms, asthmatics and asymptomatic atopics had duodenal pathological abnormalities mimicking those observed in the bronchial mucosa in asthma, suggesting that the whole mucosal immune system is involved in bronchial asthma.

Adolescent↗
PubMed1995

High-performance liquid chromatographic method for the determination of budesonide in bronchoalveolar lavage of asthmatic patients.

A simple, sensitive and selective method for the determination of budesonide in bronchoalveolar lavage (BAL) using high-performance liquid chromatography (HPLC) with UV detection was developed. BAL samples were extracted twice with methylene chloride, the extracts were centrifuged and the organic layer separated and dried under nitrogen. The samples were reconstituted in the mobile phase and 80 microliters were injected on to a Spherisorb ODS column with UV absorbance detection at 250 nm. The mobile phase was methanol-aqueous buffer (69:31, v/v). Inter-assay coefficients of variation were measured at 7.81 and 500 ng/ml with ranges of 0.89-7.31%. Average recoveries were 97% or greater. This method was successfully implemented for the analysis of BAL from asthmatics, in order to establish the amount of budesonide available to the lung and to investigate the efficacy of inhaler systems. Patients (n = 9) inhaled four puffs of 200 micrograms of budesonide and BAL was performed 10 min after the last inhalation. Only four BAL out of the nine presented detectable amounts of budesonide. The concentrations in BAL in these four patients were 13.44-84.18 ng/ml, corresponding to total amounts of 0.847-7.997 micrograms.

Administration, Inhalation↗
PubMed1995

Impaired secretion and mRNA expression of monokines by alveolar macrophages from nonsmoking patients with alcoholic liver cirrhosis.

Alveolar macrophages (AM) exposed to microorganisms secrete cytokines that are important to lung defense. Since alcoholic liver cirrhosis (ALC) patients are susceptible to lung infections, the ability of AM in such patients to produce the cytokines tumor necrosis factor-alpha, interleukin (IL)-1 beta, and IL-6 was evaluated by mRNA expression and protein secretion. Adherent AM from ALC and alcoholic patients and controls were cultured with and without lipopolysaccharide (LPS): Mean cytokine levels in ALC and alcoholic subjects were not significantly different than in controls. However, LPS-stimulated AM from 13 of 29 ALC patients exhibited a reduced ability, compared with that from controls, to secrete the cytokines (P < .05 for all 3). Specific mRNA expression was also impaired in the 13 patients, and their liver diseases were more severe than those of other patients. Impaired cytokine production by AM in ALC patients with severe cirrhosis may account for their increased susceptibility to lung infections.

Adult↗
PubMed1995

Expression of E-selectin, ICAM-1 and VCAM-1 on bronchial biopsies from allergic and non-allergic asthmatic patients.

The bronchial mucosa of asthmatic patients is characterized by a large influx of eosinophils, monocytes and lymphocytes. Leucocyte migration and accumulation is thought to involve adhesion molecules, as shown in an animal of allergic asthma and in humans with other allergic diseases. The aim of this study was to evaluate the expression of E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cellular adhesion molecule-1 (VCAM-1) on endothelium and epithelium in bronchial biopsies obtained from patients with allergic (n = 17) and non-allergic asthma (n = 18). Bronchial biopsies were taken in asthmatic patients and control subjects (n = 10) by fiberoptic bronchoscopy and embedded in paraffin. The cellular infiltrate was evaluated by May-Grünwald-Giemsa staining. Adhesion molecule expression was analyzed by immunohistochemistry using mouse monoclonal antibodies; the results were expressed as the percentage of positive cells. For each patient, we evaluated the severity of asthma as defined by the AAS score and the treatment. In controls, low expression of ICAM-1 was observed on the epithelium and endothelium (9.6 +/- 2.7 and 11.2 +/- 4.1%, respectively), while E-selectin and VCAM-1 were not expressed. In patients with allergic asthma, a significant increase of ICAM-1 expression was observed on epithelium and endothelium (28 +/- 5.3 and 35.6 +/- 5%, respectively), whereas E-selectin (17.4 +/- 4.8%) and VCAM-1 (12.8 +/- 3.6%) were overexpressed only on endothelium. In allergic asthmatic patients, adhesion molecule expression on endothelium was correlated with eosinophil and total leucocyte infiltrate (p < 0.05). In contrast, adhesion molecule expression in biopsies from patients with non-allergic asthma (14.1 +/- 5.2 and 15.3 +/- 3.6% for ICAM-1 expression on epithelium and endothelium, respectively) was not significantly different from the control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Assessment of the severity of asthma by an expert system. Description and evaluation.

Asthmaexpert, an expert system (ES), was produced at the special request of several clinicians in order to better understand the medical decisions made clinical experts in managing an asthmatic patient. We describe and evaluate this knowledge base, focusing mainly on assessment of the severity of asthma. After compiling data from a patient, Asthmaexpert assesses the severity of the disease and identifies the trigger factors involved, suggests any further investigations that may be required, and offers a treatment strategy. Implemented with Nexpert and Hypercard, it runs on a MacIntosh personal computer. The validation stage involved eight clinical experts who provided 20 case report forms (CRF) with their conclusions about management of asthma. The CRF were then programmed into the ES, which provided its own conclusions about the same subjects. Afterward, all the experts evaluated the conclusions given by ES or by their colleagues in a double-blind manner. One hundred twenty-seven CRF were available. The reliability of the experts' opinions was good, with a substantial consensus between them when assessing severity scores (kappa = 0.27 to 0.54). There was no difference in concordance of opinions on severity scores either between the experts who designed the system and ES or between the other experts and ES (weighted kappa = 0.72 and 0.69, respectively). Experts judged that the severity scores given by ES were as good as those proposed by their colleagues, and that the overall conclusions given by ES were as good as or better than those given by their colleagues. The conclusions drawn by ES were given a good rating.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
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

Ozone stimulates synthesis of inflammatory cytokines by alveolar macrophages in vitro.

Ozone (O3) is one of the major irritant oxidant gases in photochemical smog. In the present study, the in vitro effect of low concentrations of O3 (0.1 to 1 ppm) was evaluated on cell viability and cytokine secretion by alveolar macrophages (AM) from guinea pigs and healthy subjects. Cell injury was estimated immediately after O3 exposure by evaluation of ATP cell content (measured by bioluminescence) and lactic dehydrogenase (LDH) release in the culture medium. No cytotoxic effect was found: the ATP cell content of both guinea pig AM and human AM did not significantly change after O3 exposure and similarly the LDH release in the culture medium was unchanged. AM-derived cytokines (tumor necrosis factor alpha [TNF alpha], interleukin-1 beta [IL-1 beta], interleukin-6 [IL-6], and interleukin-8 [IL-8]) were evaluated in AM supernatants. O3 exposure was associated with a significant increase in cytokine secretion, with a peak value at 0.4 ppm O3. The exposure of the guinea pig AM to 0.4 ppm O3 for 60 min increased the IL-6 activity by 252 +/- 60% and TNF activity by 202 +/- 35%. The increase in monokine production by the human AM was 443 +/- 208% for TNF alpha, 484 +/- 171% for IL-1 beta, 383 +/- 147% for IL-6, and 226 +/- 45% for IL-8 after a 60-min exposure to 0.4 ppm O3. Lowest O3 concentrations (0.1 and 0.2 ppm) only increased TNF alpha secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
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

Pleural amyloidosis: thoracoscopic aspects.

We describe the case of a 60 year old man with primary amyloidosis, who suffered from peripheral neuropathy and cardiomyopathy and who presented with recurrent right pleural effusion. For this reason, he was admitted to hospital for thoracoscopic examination with pleurodesis. Macroscopic examination of the parietal pleura revealed a diffuse inflammation and light brown deposits that where covered with nodules. Biopsy specimens confirmed the amyloid deposition. This macroscopic appearance is described for the first time, and suggests that a local pleural synthesis of amyloid substance may occur during the course of systemic amyloidosis.

Amyloidosis↗
PubMed1995

Neuroradiologic aspects of Chester-Erdheim disease.

In three cases of histologically proved Chester-Erdheim disease there was a large anterior epidural lesion from C-3 to L-2 in one patient; dural masses and orbital infiltration in a second patient; and dural, choroid plexus, retroorbital, and hypophyseal lesions in a third patient. Diabetes insipidus, exophthalmia, long bone lesions, and retroperitoneal infiltration were present.

Aged↗
PubMed1995

Cytokines and cytokine network in silicosis and coal workers' pneumoconiosis.

The alveolar macrophage (AM) is a critically important cell playing a prominent role in lung inflammation via the production of oxygen radicals, enzymes, arachidonic acid metabolites, and also a large panel of cytokines. Among interstitial lung disorders, silicosis and coal workers' pneumoconiosis (CWP) are the most widespread fibrotic lung diseases. Although their pathophysiology remains incompletely understood, several lines of evidence suggest the participation of cytokines produced by AMs at least in the initiation of the alveolitis. In vitro exposure of AMs (obtained from healthy subjects) to coal dust particles triggered a significant release of tumour necrosis factor (TNF) and interleukin-6, by comparison with titanium dioxide used as a biologically inert control dust. Moreover, it appeared that coal mine dust was more aggressive than similar concentrations of pure silica, suggesting that cytokine secretion induced by coal mine dust was not exclusively related to the presence of silica but resulted from a complex interaction between the different components. In silicosis and CWP, bronchoalveolar lavage showed a large influx of mononuclear phagocytes, with an increased spontaneous production of oxidants, fibronectin, neutrophil chemotactic factor, and also of interleukin-6 and TNF-alpha. This spontaneous cytokine release was associated with an increased cytokine messenger ribonucleic acid (mRNA) expression in the lungs of coal miners.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Idiopathic acute pancreatitis and sarcoidosis.

Pancreatic involvement is rare in sarcoidosis. We describe a 30-year-old man who had two episodes of acute pancreatitis within one month with no current aetiology. Diagnosis of sarcoidosis was based on the presence of bilateral mediastinal adenopathies, alveolar lymphocytosis on bronchoalveolar lavage and biopsy of an enlarged lymph node showing multiple granulomas. This case and five others previously reported in the literature suggest the diagnosis of sarcoidosis should be considered in apparently acute idiopathic pancreatitis.

Acute Disease↗
PubMed1995

[Erdheim-Chester disease. Clinico-pathologic study of two cases].

Erdheim-Chester disease is a rare visceral xanthogranulomatosis characterized by bilateral, symmetrical sclerosis of the metaphyseal regions of long bones and infiltration of foamy, lipid-laden histiocytes. Clinically, it ranges from an asymptomatic, focal process to a fatal, systemic disease. We report two new cases, different in their presentation and extension.

Female↗
PubMed1995

[The significance of maximal expiratory concentrations of CO2 (MEC CO2) in the negative diagnosis of acute pulmonary embolism in chronic obstructive bronchopneumopathies].

The aim of this prospective study was to analyse the contribution of the measurement of alveolar arterial gradients of CO2 during forced expiration in the diagnosis of pulmonary emboli occurring in chronic airflow obstruction (COPD) as a result of smoking. The study was carried out on 178 patients: Group 1: 54 subjects without emboli (14 controls, 33 COPD and 7 patients with chest pain); Group 2: 72 patients with proved emboli (49 non COPD, 23 COPD); Group 3: 52 patients COPD presenting with varied non-embolic broncho-pulmonary pathology (pneumonia, bronchospasm, pulmonary oedema, bronchial neoplasm). The diagnosis of pulmonary emboli was confirmed by scintigraphy in patients with non COPD or angiography (in patients with COPD). The maximal fraction of CO2 was measured using a capnologue during a forced expiration which was long and prolonged until residual volume was achieved. The PaCO2 was measured simultaneously by an analysis of arterial blood gases. The D index was calculated according to the formula [(PaCO2-PEM CO2)/PaCO2] x 100. The D index was significantly lower in Group 1 (3.42 +/- 3.8% p < 0.0001) than in Group 2 (20.8 +/- 10%) and Group 3 (17.6 +/- 11.7%) (not significant between Groups 2 and 3). In patients with COPD the specificity and sensitivity and the predicted positive and negative value were 100% for a D limit of 7%. In COPD patients these values were respectively 82, 95, 75 and 96% for a D limit of 7%; on the other hand for a D below 5% the values were 60, 100, 64 and 100% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Behçet disease. Comparative aspect of diagnostic criteria].

OBJECTIVES: Different diagnostic criteria for Behçet's disease are proposed in the literature. We compared the criteria proposed by Mason and Barnes with those proposed by the International Study Group and with those proposed by the Japanese committee. METHODS: This retrospective study included 41 patients with Behçet's disease according to the criteria set by Mason and Barnes. There were 16 patients of French origin and 25 patients of North African origin. RESULTS: Genital ulcerations were more frequent in the North African population (p < 0.007) and typical Behçet skin lesions were more frequent in the French population (p < 0.021). Comparing the clinical data among the 41 patients with Behçet's disease according to the Mason-Barnes criteria revealed that only 83% met the criteria set by the International Study Group and only 54% the criteria of the Japanese committee. For the International Study Group criteria, the requirement for recurrent buccal ulcerations with at least 3 episodes over a 12 month period (a major criteria) was the most limiting element. Likewise, genital ulcerations were not always recurrent. CONCLUSION: These findings confirm the variability of clinical manifestations of Behçet's disease with ethnic origin. Proposed diagnostic criteria vary depending on the study committee and should be used as diagnostic guidelines rather than as criteria required for positive diagnosis.

Adult↗