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Biomedical subjects

A Hamzaoui

Publications and source records attributed to A Hamzaoui.

At least 37 records · Page 2Linked to original sources
PubMed1999

Lymphocytes apoptosis in patients with acute exacerbation of asthma.

Asthma is characterized by airway inflammation, which can be now assessed by the analysis of induced sputum. Ten patients with asthma were investigated during acute exacerbation for the quantification of apoptosis, for Bcl-2 and Fas expression, in induced sputum lymphocytes. They were compared to 12 patients with chronic obstructive pulmonary disease (COPD), and 10 healthy controls. Spontaneous apoptosis was determined by staining nuclei with propidium iodide, and analyzed with a FACScan. Bcl-2 was measured by Western blotting, and results were obtained by densitometric scanning, done by the gel proanalyser. The investigation of Fas was performed using the streptavidin-biotin preroxidase-complex method. Patients with asthma and patients with COPD exhibited a significant increase of cellularity, percentage of neutrophils, eosinophils and lymphocytes when compared to healthy controls. Apoptosis in induced sputum mononuclear cells was found decreased in patients with asthma compared to COPD patients and healthy controls. The quantification of apoptosis was measured after exposure to anti-cytokine antibodies. Anti-TNF-alpha antibody blocked the apoptosis in both patients groups and healthy controls, suggesting that TNF-alpha acted as an inducer of apoptosis. Anti-IL-10 blocked apoptosis completely exclusively in patients with asthma. Bcl-2 expression was found to be increased in induced sputum mononuclear cells from patients with asthma, compared to healthy controls and patients with COPD. Expression of Fas could be detected in patients with asthma, at a lower level than COPD patients and healthy controls. Distinct mechanisms of apoptosis were found in patients with asthma and patients with COPD, characterized by different levels of Bcl-2 and Fas expression. Induction of apoptosis should be a beneficial process in allergic inflammation traduced in induced sputum mononuclear cells. The apoptosis process is assumed by two different mechanisms in asthma and COPD. Our findings indicated that in asthmatic patients, activated lymphocytes accumulate in the bronchi; because of their prolonged survival that maintains inflammation.

Adult↗
PubMed1999

Expression of Bcl-2 in inflammatory sites from patients with active Behçet's disease.

Behçet's disease (BD) is a current systemic vasculitis of unknown aetiology. Eyes, skin, joints, the oral cavity, genital system, blood vessels, central nervous system and lung are usually involved. Defective regulation of programmed cell death (apoptosis) may play a role in the development of (BD), and the proto-oncogene Bcl-2 is involved in the control of apoptosis in immunocompetent cells. We therefore wished to investigate the expression of Bcl-2 in the peripheral lymphocytes and in two inflammatory sites of patients with active BD: bronchoalveolar lavage (BAL) and cerebrospinal fluid (CSF) lymphocytes. Levels of Bcl-2 expression in the lymphocytes of patients with BD and, for comparison, in the lymphocytes of healthy controls and non-inflammatory neurological diseases (NIND), were studied by two-colour cytofluorography and RNA analysis. In BD patients, a significant proportion of T cells expressed increased amounts of Bcl-2 protein, both in peripheral blood and in inflammatory sites. Mononuclear cells of patients with BD showed increased amount of Bcl-2 messenger RNA. The in vitro incubation of T lymphocytes with IL-10, significantly increased the Bcl-2 expression, specifically in T lymphocytes from inflammatory sites. In active BD, stimulation of HSV-1 T lymphocytes slightly increased Bcl-2 expression, not significantly different from unstimulated HSV-1 T cells. The occurrence of circulating T lymphocytes with abnormally high Bcl-2 expression in peripheral circulation and in inflammatory sites may be explained in part by the increased in vivo activation levels, and by aetiopathological agent(s): our findings seem to indicate an important role in the chronic inflammation in BD.

Adolescent↗
PubMed1998

Levels of soluble Fas/APO-1 in patients with Behçet's disease.

The aim of this study was to quantify soluble Fas/APO-1 (sFas/APO-1) protein in the serum of patients with Behcet's disease (BD) in active and inactive stages, compared with patients with systemic lupus erythematosus (SLE) and patients with rheumatoid arthritis (RA). Soluble Fas/APO-1 was quantified using a sandwich enzyme-linked immunosorbent assay. Increased serum sFas/APO-1 levels were observed in active BD, compared with inactive BD, RA patients and SLE patients. Increased serum sFas/APO-1 levels were correlated with the presence of neurologic manifestations or pulmonary involvement in active BD. In conclusion, increased levels of sFas/APO-1 occurred frequently and exclusively in active BD patients. Preliminary evidence suggested that elevated levels of sFas/APO-1 are associated with the clinical stage and clinical manifestations in BD.

Adult↗
PubMed1997

Usefulness of longitudinal evaluation of Cyfra 21-1 variations in advanced lung cancer monitoring.

To investigate the usefulness of Cyfra 21-1 as an indicator of therapy effectiveness and prognosis in advanced primary lung cancer, sixty-three patients were selected on the basis of a high Cyfra 21-1 serum level (> 3.3 ng/ml) at the time of diagnosis. Serial assays of Cyfra 21-1 were performed during the first three courses of chemotherapy among 63 patients. The serial-values were analysed according to response to treatment and overall survival. After three courses of chemotherapy, a 70% reduction under the initial marker's value or a return to normal was observed for 36 patients. Twenty-two (61%) of these patients presented an objective response to therapy, making Cyfra 21-1 a moderate indicator in terms of positive predictive value (PPV). However, a significant decrease of Cyfra 21-1 was observed in 88% (sensitivity) of the 25 objective responders. Cyfra 21-1 changes after one course of chemotherapy (61 patients) were not sufficient to predict the future response after three courses (sensitivity 52%, specificity 56%, PPV 45%). Among 30 clinical or radiological relapses, a 10% increase or a return upper reference limit in Cyfra 21-1 level was observed in 18 cases (sensitivity 60%, specificity 100%, PPV 100%). Survival data were available for 61 patients. No significant statistical difference (P > 0.05) was found between survival curves depending on a significant decrease of Cyfra 21-1 after the first course of chemotherapy. We can conclude that the only interest of serial Cyfra 21-1 assays may be the detection of relapse, where one observes a significant decrease of the marker correlated with an objective response to first treatment.

Adult↗
PubMed1996

Endothelin-1 expression in serum and bronchoalveolar lavage from patients with active Behçet's disease.

In view of the pulmonary manifestations in Behçet's disease (BD), we investigated the production of endothelin-1 (ET-1) by the respiratory tract in active BD. A group of 10 patients with active BD with pulmonary manifestations and 10 control subjects were studied. Immunoreactive ET-1 was measured in BAL and in serum by RIA. All the BD patients exhibited higher BAL ET-1 levels than controls. ET-1 expression may contribute to the functional and morphological abnormalities of the vasculature associate with BD.

Adult↗
PubMed1996

The superiority of hollow fiber membrane over bubble oxygenator in a perfusion circuit for the evaluation of small caliber endothelialized arterial prostheses.

A perfusion circuit was constructed from a pneumatic ventricular assist device, 2 compliance chambers, 4 small-diameter silicone tubes (ID 4 mm) simulating shear inducing vascular prostheses, and an oxygenator with a heat exchanger. A bubble oxygenator (in a BO circuit) and a hollow fiber membrane oxygenator (in an MO circuit) were studied. The circuits were perfused with 30% human serum containing culture medium for 7 days at 37 degrees C. The pH, Po2, PCo2, Na+, K+, Ca2+, Cl, glucose, and total protein concentrations remained the same in BO and MO circuits during the 7 days of perfusion. The differences between the values measured in the perfusion medium and in the medium maintained in the static conditions of cell culture were not significant. In the BO circuit, the amount of cholesterol and triglyceride concentrations decreased whereas the relative amounts of albumin, alpha 1, alpha 2, beta, and gamma globulins remained stable in the perfusion medium. The medium from the BO circuit did not promote the proliferation of cultured human saphenous vein endothelial cells. In the medium from the MO circuit, the cholesterol and triglyceride concentrations did not change with perfusion time; the proliferation rate and anticoagulant function of endothelial cells were maintained. The hollow fiber membrane oxygenator preserves the biological characteristics of the cell culture medium in a perfusion circuit. The MO circuit permits the performance of relevant studies on shear stress resistance and functional activity of human endothelial cells seeded onto vascular prostheses.

Blood Vessel Prosthesis↗
PubMed1994

Phenotype and functional profile of T cells expressing gamma delta receptor from patients with active Behçet's disease.

OBJECTIVE: Our aim was to investigate the TCR gamma delta+ subset in Behçet's disease (BD) inflammatory sites, which better reflects changes associated with the pathologic process than peripheral blood. METHODS: Forty-five patients with active BD, 10 patients with recurrent aphthous ulcers, 12 patients with rheumatoid arthritis, 5 patients with noninflammatory neurologic diseases and 15 healthy individuals were studied. Three monoclonal antibodies TCR delta 1, BB3, and A13 were used to assess the percentage of TCR gamma delta+ in peripheral blood mononuclear cells (PBMC), in bronchoalveolar lavage and cerebrospinal fluid (CSF). CD11a/CD18 was used to study adhesion molecules. TCR gamma delta+ cells isolated by immunomagnetic separation were tested for cytolytic activity against K562 target cells after interleukin 2 stimulation. RESULTS: The PBMC TCR gamma delta BB3+ subset was significantly increased in BD. In BD inflammatory sites, TCR gamma delta+ cells were also present, composed mainly of A13+ cells from these sites also expressed CD11a marker. TCR gamma delta+ cells from inflammatory sites displayed a higher cytotoxic activity than controls, mediated by the A13+ subset. CONCLUSION: The accumulation of cytotoxic TCR gamma delta+ cells at the sites of inflammation suggests their involvement in the local injury process.

Adult↗