Biomedical subjects
Publications and source records attributed to D Dusser.
A 29-y-old woman from Congo Democratic Republic was admitted to hospital with dyspnoea of 5-months duration. Chest X-ray showed left white lung and infiltrates of the right superior lobe. The patient underwent left pneumonectomy. Histopathological examination showed pulmonary cavitary lesions and bronchectasis full of branching septated fungi. Cultures yielded Scedosperium apiospermum.
Eosinophils are the most characteristic inflammatory cells in the airway mucosa in asthma. Eosinophils release highly toxic products and cytokines which may influence the immune system, amplify the inflammatory response and participate in damaging and remodeling processes that occur in the airway mucosa. Eosinophilic inflammation in asthma is related to the blunted perception of bronchoconstriction. The magnitude of eosinophil influx and the degree of activation of these cells in the airway mucosa are related to the severity of asthma and appear to play a key role in some cases of asthma death. The number and activation of eosinophils in the airway mucosa are related to the magnitude of airway hyperresponsiveness to bradykinin but not to an agonist acting directly on smooth muscle such as methacholine. Inhaled corticosteroids reduce eosinophil inflammation in asthma whereas beta 2-agonists appear to increase the magnitude of eosinophilic inflammation induced by allergen exposure. The eosinophilic inflammation can be assessed by non-invasive methods using sputum analysis and, indirecly, by measuring the airway reactivity to bradykinin.
We have studied the characteristics of 202 cystic fibrosis adult patients, all with chronic respiratory symptoms, with a median age of 27 yrs (18 to 55 yrs) and a male predominance (56%). At genetic analysis, delta F508 homozygotes were 41%, delta F508 heterozygotes 42% and 17% had no delta F508. The respiratory disease was more severe and complications were more frequent in adults: hemoptysis in 14%, pneumothorax in 15%, lung transplantation in 25 patients. Chronic bronchial colonisation with Pseudomonas aeruginosa, in 76% of patients, contributed to making treatments more severe because of antibiotic i.v. courses and nebulised antibiotics. Respiratory function showed a mean FVC of 62 +/- 22% and a mean FEVI of 48 +/- 94%. External pancreatic insufficiency was found in 83%, diabetes in 14%. Intestinal occlusion syndromes were observed in 11% of patients and hepatic cirrhosis in 8%. In spite of the severity of the respiratory disease, theses patients succeeded in social and occupational insertion; 62% were independent, 18% had children and 77% were working or studying. Analysis of the patients according to age at diagnosis showed that, in 38 patients diagnosed after the age of 18 yrs, the respiratory disease was less severe, pancreatic insufficiency and non-respiratory complications were less frequent (34% had pancreatic insufficiency, 5% had diabetes and none had cirrhosis). This may partly be due to the presence of milder CFTR mutations. In conclusion, cystic fibrosis in adulthood frequently looks like an evolutive form of cystic fibrosis in childhood. Nevertheless, some late diagnosed forms in adults, with better prognosis, have been recently identified.
The inflammatory pathogenesis in airways of patients with cystic fibrosis (CF) is still unresolved. We demonstrate here that in in situ human DeltaF508 homozygous CF bronchial tissues, submucosal gland cells exhibit an absence of inhibitor factor kappaBalpha (IkappaBalpha) and high levels of chemokine interleukin-8 (IL-8) expression. These results were confirmed by cultured human CF bronchial gland cells in which a lack of cytosolic IkappaBalpha and high levels of constitutively activated nuclear factor kappaB (NFkappaB) associated with an up-regulation of IL-8 production (13-fold increase) were found when compared to non-CF (control) disease bronchial gland cells. We also demonstrated that the isoflavone genistein, a well known CFTR mutant Cl(-) channel stimulator, significantly reduces the endogenous and Pseudomonas aeruginosa lipopolysaccharide-induced IL-8 production in cultured CF bronchial gland cells by increasing cytosolic IkappaBalpha protein levels. Overall, results show that genistein is a potent inhibitor of the activated NFkappaB identified in CF gland cells. This strong inhibition of constitutively activated NFkappaB and the resulting down-regulation of IL-8 production by genistein in the CF gland cells highlights the key role played by cytosolic IkappaBalpha in the regulation of inflammatory processes in CF human airway cells.
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BACKGROUND: Allergic asthma is a multifactorial and probably multigenic inflammatory disease of the upper airways, and has been associated with the HLA class II alleles DR4 and DR7. Here we investigated possible associations with other polymorphic susceptibility/resistance genes located within the major histocompatibility complex, i.e., the genes coding the major 70-kDa heat-shock proteins (HSP; Hsp70) hsp70-1, hsp70-2, and hsp70-HOM, whose products are overexpressed in the bronchi of asthmatic patients. METHODS: Genomic DNA was extracted from peripheral blood lymphocytes or buccal epithelial cells of 48 patients with allergic asthma and 31 selected nonatopic control subjects, in whom we previously reported a strong association of atopy with DR4/DR7 alleles. RESULTS: No evidence was found for an independent role of hsp70 gene polymorphism in susceptibility to allergic asthma. However, hsp70 alleles might be involved in extended haplotypes of HLA markers. CONCLUSIONS: Our data suggest that Hsp70 overexpression in asthma results from complex interactions between environmental exposures and genetic background rather than from specific genetic variations in hsp70 genes.
Evolution of lung damage is highly variable in cystic fibrosis (CF) even in patients with the same cystic fibrosis transmembrane conductance regulator (CFTR) mutations. The analysis of genetic factors other than CFTR may help our understanding of genotype-phenotype relationships in CF. As human leukocyte antigen (HLA) class II polymorphism has been associated with a number of diseases including autoimmune and inflammatory diseases, asthma, and allergy, we investigated the possibility that HLA polymorphism contributes to CF-associated pulmonary inflammation. Among the 98 adult CF patients tested, the genotypic frequencies of DR4 and DR7 alleles (serologic group DR53) and DR7/ DQA*0201 haplotype were higher than in 39 selected control subjects without atopy (p </= 10(-)6, relative risk [RR] = 22, and p </= 5.10(-)4, RR = 27, respectively) and in a random population. No significant difference of these allelic distributions was found according to the CFTR genotype. In the CF patients, the DR7 allele was significantly associated with an increase in total IgE and with chronic Pseudomonas aeruginosa colonization (100% of DR7 versus 83% of non-DR7 patients being colonized, p < 0.05). Our results suggest that genetic factors known to modulate the immune response might contribute to chronic infection with Pseudomonas, increased total IgE, and pulmonary outcome in CF.
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Nebulization is a basic treatment for the management of severe acute asthma. Three mechanisms are involved in bronchial obstruction: bronchospasms, inflammation and an increase in bronchial secretions. Combination therapy including beta 2-sympatheticomimetic and synthetic atropinic drugs is strongly synergistic. In a French multicenter trial including 45 adult patients presenting with asthma, combination of nebulized Berotec and Atrovent was studied. It proved to be efficacious in two thirds of the patients. Results were even better for younger patients whose initial peak flow rate was high. Tolerance to this combination therapy was as good as that to beta 2-sympatheticomimetic monotherapy.
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Using in vitro amplification of cDNA by the polymerase chain reaction, we analyzed alternatively spliced events of cystic fibrosis transmembrane conductance regulator gene in lymphoblastoid cells. Ten alternatively spliced transcripts were identified using analysis of 6 overlapping segments of amplified cDNA, 4 of which have not been described previously. These include transcripts lacking exon 16, 17b, 22 and a transcript resulting from the use of a cryptic acceptor and donor splice sites. Moreover, in 2 cystic fibrosis (CF) patients bearing nonsense mutations E60X or W1282X, we observed that nonsense mutations are associated with an alteration of splice site selection in vivo resulting in exon skipping of constitutive exons or in the use of cryptic splice sites. In addition, even though lymphoblastoid cells are not the relevant tissue to address the question of the relationship between clinical respiratory phenotype and genotype, our results concerning adult CF patients (delta F508/ delta F508) suggest that individual-specific RNA splicing patterns could influence the severity of the CF pulmonary disease. If this phenomenon of alternative splicing events proves to be significant in CF and to be a common feature of disease genes, the study of RNA splicing could become an important tool for the analysis of the genotype-phenotype relationship in many inherited disorders.
OBJECTIVE: The aim of this investigation was to determine the delay between the first symptom and diagnosis of pulmonary tuberculosis and onset of treatment. STUDY DESIGN: Fifty-two consecutive patients presenting with confirmed pulmonary tuberculosis over an 18 month period (June 1, 1991 to December 31, 1992) at the Cochin Hospital in Paris. RESULTS: The mean delay between first symptom and diagnosis was 2 weeks in 14 patients (27%), 3 to 4 weeks in 10 patients (19%) and over 4 weeks in 28 patients (54%). The delay between diagnosis and onset of treatment was less than 8 days in 39 patients. CONCLUSION: Delay was not shorter when symptoms were present. This situation could have an effect on tuberculosis morbidity.
BACKGROUND: Atopy, with or without associated asthma, provides a useful model for evaluating the genetic factors that control human immune responsiveness. HLA class II gene products are involved in the control of immune responses. OBJECTIVES: We investigated whether susceptibility or resistance to the disease was associated with HLA class II genes. METHODS: Blood samples were obtained from two groups of unrelated European-born white adults: 56 atopic patients (52 of them with asthma) and 39 healthy controls with no personal or familial history of asthma or atopy. Genomic DNA was extracted from peripheral blood lymphocytes. The exons of DQA1, DQB1, DRB and DPB1 genes were selectively amplified by the polymerase chain reaction (PCR) method. Genotyping was carried out by digestion of the amplified DNA products with allele-specific endonucleases (PCR-RFLP), which can recognize allelic variations in the polymorphic exon. RESULTS: We found no significant differences in the frequency of DPB1 alleles between patients and controls. HLA class II DR4 and DR7 alleles were present in 39.2% of the patients and in 2.5% of the healthy subjects (Pc*2 < or = 3.9 10(-3)). Conversely, DQA1*0103 and DQB1*0502 alleles were more frequent in the control subjects. These results confirm a previous study of an extended pedigree, which showed that DR4 and DR7 alleles were absent in all healthy members of the family and were frequently observed in atopic and/or in asthmatic subjects. CONCLUSION: We observed that HLA-DR 4 and DR7 alleles are significantly implicated in their susceptibility to the disease and suggest that this susceptibility is more related to atopy than to specific responses to allergens. According to previous studies, we could also submit that in atopic patients with asthma, DR4 alleles at the least, could be more closely associated with atopy than with asthma per se. Conversely, we suggest that some allelic DQA1 and DQB1 sequences might confer protection against the disease.
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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)