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Biomedical subjects

P Demoly

Publications and source records attributed to P Demoly.

At least 145 records · Page 8Linked to original sources

[Vectors of gene transfer. Applications in pneumology].

Human gene therapy in 1996 is a reality with almost 100 trials world-wide involving nearly 450 patients. The stakes are enormous. To assure the efficacy and safety of such a regime is mainly a problem of vector to carry the chosen nucleotide sequences. The ideal vector should have as a unique function that of the transport of the gene of therapeutic interest to the desired area at the proper quantity. The ideal vector does not currently exist and each system, viral or non-viral has both advantages and inconveniences.

Base Sequence↗

[The epidemiology and genetics of asthma. I. Descriptive epidemiology and analysis of environmental factors].

Asthma is regarded as a disease with a complex interaction between genetic and environmental factors. Since the end of the 1970s and during the 80s the world has seen an increase in the prevalence, morbidity and mortality linked to asthma. The rapidity of progress of this phenomenon means that it cannot be explained only by modification of genetic factors and stresses the preponderance of exogenous factors. The purpose of this review is to examine the epidemiological knowledge of these environmental factors and of the genetic factors in asthma in order to underline how these genetic and exogenous factors interact and modulate the occurrence of the asthmatic disease. In the first part of this general review we will discuss the epidemiology of asthma in terms of prevalence, incidence, mortality, cost and socio-professional and scholastic repercussions and will underline for each environmental factor its causal role and/or exacerbation in asthma as well as its contribution in the increased prevalence and severity of asthma. In the second part of this general view we touch on the epidemiological knowledge of the genetics of asthma and of atopy.

Absenteeism↗

[The epidemiology and genetics of asthma. II. Genetic aspects of the epidemiology of asthma and atopy].

Asthma is regarded as a disease with a complex interaction between genetic and environmental factors. Since the end of the 1970s and during the 80s the world has seen an increase in the prevalence, morbidity and mortality linked to asthma. The rapidity of progress of this phenomenon means that it cannot be explained only by modification of genetic factors and stresses the preponderance of exogenous factors. The purpose of this review is to examine the epidemiological knowledge of these environmental factors and of the genetic factors in asthma in order to underline how these genetic and exogenous factors interact and modulate the occurrence of the asthmatic disease. In the first part of this general review we discussed the epidemiology of asthma in terms of prevalence, incidence, mortality, cost and socio-professional and scholastic repercussions and underlined for each environmental factor its causal role and/or exacerbation in asthma as well as its contribution in the increased prevalence and severity of asthma. In the second part of this general view we touch on the epidemiological knowledge of the genetics of asthma and of atopy.

Asthma↗

Fos immunoreactivity assessment on human normal and pathological bronchial biopsies.

The transcription factor Fos is involved in cell proliferation and differentiation. Its expression in normal and pathological adult human tissues and cells has rarely been studied. We therefore studied bronchial biopsies obtained from 14 normal subjects (NS), 18 non-steroid-treated asthmatics, 10 corticosteroid-treated asthmatics and 10 patients with chronic bronchitis (CB), in addition to 34 patients with lung cancer (LC), by immunofluorescence for Fos immunoreactivity, using a highly specific polyclonal antibody. Bronchial tissue of 0/10 NS, 11/18 non-steroid-treated asthmatics, 1/10 steroid-treated asthmatics, 0/10 CB and 1/34 LC expressed Fos. In asthmatic patients, the expression was heterogeneous, localized to epithelial cells and correlated with the epithelium shedding (tau = 0.45, P = 0.0001). Corticosteroid-treated patients rarely expressed Fos, suggesting a role for this proto-oncogene in asthmatic bronchial inflammation. Fos was rarely expressed in the normal and pathological (CB, LC) proliferative compartment of the human bronchi, suggesting its low role in cell proliferation of the large airways.

Adenocarcinoma↗

IFN-gamma activates superoxide anion production in blood monocytes from allergic asthmatic patients.

BACKGROUND: Peripheral blood monocytes may participate in allergic diseases by releasing inflammatory mediators. We have recently shown enhancement of nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase activity in adherent human peripheral blood monocytes from allergic patients when immunoglobulin E (IgE) binds to its low affinity receptor. Interferon-gamma (IFN-gamma), a monocyte-activating lymphokine, has been shown to prime monocytes for superoxide anion release. OBJECTIVE: We hypothesized that IFN-gamma could directly activate blood monocyte superoxide anion release and evaluated its modulatory effect on IgE-induced superoxide anion release from those cells. METHODS: Seven patients with allergic asthma, 6 patients with allergic rhinitis, and five nonallergic controls were studied. We measured superoxide anion release from their blood monocytes using a chemiluminescence assay. Cells were either nonstimulated, or stimulated for 30 minutes with IFN-gamma and/or serum IgE. RESULTS: We found that IFN-gamma stimulated superoxide anion production and decreased the IgE-induced superoxide anion production after 30 minutes of IFN-gamma preincubation only in blood monocytes from patients with allergic asthma. CONCLUSIONS: These data suggest that IFN-gamma receptors may be increased and/or coupled to NADPH oxidase in allergic asthmatic patients.

Adult↗

[Oncogenes and anti-oncogenes in lung cancer].

In all normal cells, two type of genes, oncogenes and anti-oncogenes, are expressed and control cell proliferation and differentiation. Cell growth is stimulated by oncogenes and inhibited by anti-oncogenes. Cancerization involves loss of control due to defective gene expression either by overexpression of a normal protein (loss of quantitative control) or expression of an abnormal protein (loss of qualitative control). Several oncogenes have been identified. They include three oncogenes, c-myc, N-myc and L-myc, known to be overexpressed in small-cell carcinomas of the lung. Point mutations of the oncogene K-ras is found in 15 to 30% of adenoma carcinomas, especially in smokers. Loss of anti-oncogene function has also been described in processes leading to lung cancer. Chromosome abnormalities, for example the 3p14-23 deletion described in 1982, are found in 100% of small-cell carcinomas and in 50% of non-small-cell carcinomas. This deletion is never found in normal tissue. The gene involved has not yet been cloned. Other mutations or deletions include the RB gene, necessary for neuroendocrine differentiation, and the p53 gene which has undergone mutation in 50% of the non-small-cell carcinomas and 70% of the small-cell carcinomas. These acquired mutations are strongly associated with tobacco smoking. Oncogenes and anti-oncogenes play an important role in the complex step-wise process leading to cancerization. As tumour characterization becomes more precise and precancerous states better controlled, future treatments may relief on inhibiting tumoural growth by using drugs which would substitute for the lost effect of anti-oncogenes or inhibit activation of an oncogene. But at the present time, it is still difficult to define criteria predicting high risk of postoperative relapse or resistance and further studies investigating the correlation between genetic abnormalities and clinical staging and survival curves are required.

Cell Transformation, Neoplastic↗

Assessment of inflammation in noninfectious chronic maxillary sinusitis.

BACKGROUND AND AIM: Pathologic examination of the sinus mucosa and titration of inflammatory mediators in the sinus fluid were carried out to characterize inflammation in chronic sinusitis and determine whether patients with chronic allergic rhinitis (CAR) and sinusitis differ from patients with chronic nonallergic rhinitis (CNAR) and sinusitis. METHODS: Nine control subjects (patients requiring ear, nose, and throat surgery not related to sinusitis), 12 patients with CAR and sinusitis, and 13 patients with CNAR and sinusitis were investigated. Eosinophil cationic protein, tryptase, myeloperoxidase, histamine, and prostaglandin D2 were measured in the sinus lavage fluids, and cells were enumerated. The cellular infiltrate was studied by immunohistochemistry with monoclonal antibodies against eosinophil cationic protein (eosinophils), tryptase (mast cells), neutrophil elastase (neutrophils), CD3 (lymphocytes), CD68 (macrophages), and proliferating cell nuclear antigens. RESULTS: Neutrophils were not increased in sinusitis. In comparison with control subjects, patients with CAR and CNAR with sinusitis showed significant increases in eosinophils and macrophages in biopsy specimens and in eosinophil cationic protein in sinus lavage fluids. In comparison with patients with CNAR, patients with CAR had an increased number of intraepithelial mast cells and lymphocytes. CONCLUSIONS: These findings suggest that patients with CNAR and sinusitis can be distinguished from patients with CAR and sinusitis, which resembles nonallergic rhinitis with eosinophilia syndrome.

Adolescent↗

IgE produces monocyte superoxide anion release: correlation with CD23 expression. Comparison of patients with asthma, patients with rhinitis, and normal subjects.

Allergic inflammation involves many different cell types among which mononuclear cells, such as macrophages and monocytes, play an important role. These cells release numerous chemical mediators, including superoxide anion (O2.-). We evaluated the capacity of atopic serum to stimulate peripheral blood monocyte O2.- release. Thirteen untreated allergic patients (seven with asthma and six with rhinitis), and five nonallergic control subjects were studied. O2.- was measured in a photon-counting camera with Lucigenin-enhanced (Sigma Chemical Co., St. Louis, Mo.) chemiluminescence. Results were expressed (mean +/- SEM) in relation to basal values (peak/basal chemiluminescence values). Spontaneous production of O2.- was greater in allergic patients. Moreover, atopic serum stimulated O2.- production of blood monocytes in all subjects, but this was greater in subjects with allergic asthma than in subjects with allergic rhinitis and normal subjects. Anti-IgE immunoadsorption of atopic serum completely abrogated this effect, which was restored by the IgE-rich eluted fraction. IgE-induced O2.- release decreased as adherence duration increased and was correlated with surface CD23 expression. These results indicate that monocytes from allergic patients are in an activated state and that binding of IgE to their receptors generates O2.-, possibly by direct activation of blood monocyte reduced nicotinamide adenine dinucleotide phosphate oxidase.

Adult↗

Cell proliferation in the bronchial mucosa of asthmatics and chronic bronchitics.

In chronic inflammatory diseases, cells are recruited but may also derive from local proliferation. In normal bronchial epithelium, under 5% of cells are in cycle but in asthma and chronic bronchitis, proliferation may occur. Cycling cells can be identified by immunohistochemistry using PC10 monoclonal antibody (Proliferating Cell Nuclear Antigen, PCNA). We enumerated PCNA-positive cells (labeling index = LI) in bronchial biopsies of 11 healthy non-smokers (HNS), seven healthy smokers (HS), 30 non-smoking asthmatics (NSA), six smoking asthmatics (SA) and 18 chronic bronchitics (CB). Twenty non-small cell lung cancer patients were used as positive control subjects. Ciliated and secretory cells were PCNA-negative. Basal cells were PCNA-positive in one of the 11 HNS (LI = 0.18 +/- 0.60), none of the seven HS, two of the 30 NSA (LI = 0.05 +/- 0.20), two of the six SA (LI = 2.4 +/- 4.3) and 11 of the 18 CB (LI = 12 +/- 20). In smokers, PCNA positivity correlated with tobacco consumption (Rho = 0.62, p < 0.0008) and in patients with chronic bronchitis, with the degree of metaplasia (tau = 0.815, p < 0.0001). The submucosa of most subjects showed no PCNA immunoreactivity. These findings suggest that the bronchial mucosa of nonsmokers is not hyperproliferative, even in asthmatics. Tobacco smoking increases PCNA immunoreactivity, possibly leading to the metaplasia of chronic bronchitis.

Adolescent↗

Comparative analysis of cellular and tissular expression of c-fos in human keratinocytes: evidence of its role in cell differentiation.

Recent studies on normal and pathological skin have suggested a role of the c-fos proto-oncogene in keratinocyte differentiation. To further elucidate this question we have used keratinocyte and skin culture models to study in vitro regulation of c-fos expression and attempted to correlate it with the keratinocyte maturation process. Our results show that c-fos expression is prolonged in keratinocyte monolayers both at the mRNA and protein level. Extracellular calcium which stimulate keratinocyte differentiation is able to induce c-fos expression in the presence of growth factors. However this c-fos expression cannot be maintained by these factors as seen in normal human skin in vivo. Conversely, spontaneous expression of c-fos can be seen in reconstituted skin when the neo-epidermis has completed its differentiation. All these data strongly support a role of c-fos as a switch between the early and late phases of keratinocyte differentiation allowing them to be definitively committed to their elimination process. Additionally, a differential regulation of c-fos seems to exist between keratinocyte culture and reconstituted epidermis, suggesting that tissular and serum factors are involved in the prolonged c-fos expression observed in human epidermis.

Animals↗

[The gene or genes of allergic asthma?].

Asthma is a multifactorial disease in which the hereditary component has been demonstrated by familial and identical twin studies. Allergy is important in the aetiology of asthma and is characterized by a hyperreaction to allergens triggering predominantly the immunoglobulines E. The levels of these antibodies are found to be elevated even in non allergic asthmatics. The majority of genetic research in this area is focused on either the genes of the specific immune response or that of the non allergic response. These are the genes of the class II MHC, and the APY gene on chromosome 11q respectively. The modern techniques of molecular genetics and in particular those of inverse genetics have recently contributed to a more comprehensive understanding of this disease.

Animals↗

Airway macrophages from patients with asthma do not proliferate.

BACKGROUND: Macrophages are involved in asthma, but their pulmonary turnover is unknown. We compared the ability of bronchoalveolar lavage (BAL) and bronchial macrophages to proliferate in normal subjects and patients with asthma. METHODS: BAL cells from eight patients with asthma and eight normal volunteers were separated with a discontinuous Percoll gradient (Pharmacia Fine Chemicals, Uppsala, Sweden). In a first experiment, nuclei of each alveolar macrophage (AM) fraction, stained with propidium iodide, were analyzed for DNA content with a flow cytometer, and the proportions of cells in the G0/G1, S, and G2 + M phases were determined. In a second experiment, expression of Ki-67-related antigen was sought on AMs by immunocytochemistry. Macrophages from 10 patients with asthma and 10 normal volunteers were studied in biopsy specimens by means of immunohistochemistry with a panmacrophage monoclonal antibody (HAM-56) and a monoclonal antibody against proliferating cell nuclear antigen. RESULTS: The proportions of BAL AMs in the different phases of the cell cycle were similar in normal subjects and patients with asthma for all fractions, and the percentage of cells in S and G2 +/- M phases ranged from 7.3% to 11.3%. Under 1% of BAL AMs expressed Ki-67-related antigen. None of the macrophages present in the biopsy specimens expressed proliferating cell nuclear antigen. CONCLUSIONS: This study does not indicate that an important source of airway macrophages is local proliferation.

Adolescent↗

Neural cell adhesion molecule and prognosis of surgically resected lung cancer.

The prognostic significance of the expression of neural cell adhesion molecule (NCAM), a neuroendocrine antigen in lung cancer, was analyzed by an indirect immunoperoxidase method in 97 surgically treated patients. Reactivity of MOC-1 and S-L 11.14, both cluster-1 monoclonal antibodies directed against NCAM, was positive in all nine small-cell lung cancers and in 16 of 88 (18%) non-small-cell lung cancers. For the latter group, this expression demonstrated a phenotypic heterogeneity that was mainly observed in poorly differentiated squamous cell carcinomas and in stage N2 non-small-cell lung cancers. Patients with NCAM-positive non-small-cell lung cancer proved to have a shorter survival than those with NCAM-negative disease. In Cox's model for multivariate analysis, nodal status and histology were the main independent determinants of prognosis. We therefore concluded that NCAM expression in non-small-cell lung cancer is correlated to nodal status and that it indicates a poor prognosis. These findings confirm that the diversification of lung cancer phenotype leads to tumor progression and brings a negative prognosis to surgically resected non-small-cell lung cancer. However, nodal status remains the most important prognostic variable, suggesting that NCAM expression is only one of numerous biological events that promote tumor progression.

Adenocarcinoma↗

Conjunctival provocation tests with codeine phosphate. Effect of disodium cromoglycate.

The reactivity of ocular mast cells is poorly characterized in man. Provocation tests with codeine phosphate, a molecule known to activate connective tissue mast cells, were performed in ten normal subjects. Ten-fold increasing concentrations of codeine phosphate (10(-5) to 10(-1) mg/mL) were tested in both eyes until a positive challenge was observed. Schirmer strips were placed under the eyelid and left for five minutes. A negative control was performed ten days later. All subjects had a strongly positive reaction for the same codeine phosphate concentration (10(-1) mg/mL). Histamine was released in 8/10 subjects (control: 7.06 +/- 4.19 nM/L, codeine phosphate: 18.2 +/- 15.7 nM/L, P < .018), PGD2 was released in 8/10 subjects (control: 0 codeine phosphate: 273.3 +/- 408.9 ng/L). Disodium cromoglycate blocked the release of histamine and PGD2. Codeine phosphate is potent at causing mast cell activation in the eye and this effect is blocked by disodium cromoglycate.

Adult↗

[Treatment of bronchial inflammation].

Inflammation is a general defence mechanism. It is constant in asthma where it is characterized by the presence of eosinophils in sputum and blood. Treatment of bronchial inflammation is one of the master pieces of therapeutic strategy and relies on inhaled corticosteroids in most cases. These drugs are remarkably effective and can be used for long periods with little or no side-effects, but compliance with treatment must be checked regularly. In all cases, even when corticosteroids are the mainstay of maintenance treatment, bronchodilators must be used simultaneously. The triggering factors must be taken into account and re-evaluated according to the course of the disease. In the short-term all efforts must concentrate on educating the patients and making sure that they comply with their treatment. In the mid-term new, more effective steroids with even less side-effects than the others can be tried. In the long-term anti-inflammatory agents might multiply and be prescribed in combinations for successful cure of a multifactorial syndrome.

Asthma↗