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Biomedical subjects

Deborah Miotto

Publications and source records attributed to Deborah Miotto.

6 recordsLinked to original sources

Chronic obstructive pulmonary disease (COPD) and occupational exposures.

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality in both industrialized and developing countries. Cigarette smoking is the major risk factor for COPD. However, relevant information from the literature published within the last years, either on general population samples or on workplaces, indicate that about 15% of all cases of COPD is work-related. Specific settings and agents are quoted which have been indicated or confirmed as linked to COPD. Coal miners, hard-rock miners, tunnel workers, concrete-manufacturing workers, nonmining industrial workers have been shown to be at highest risk for developing COPD. Further evidence that occupational agents are capable of inducing COPD comes from experimental studies, particularly in animal models. In conclusion, occupational exposure to dusts, chemicals, gases should be considered an established, or supported by good evidence, risk factor for developing COPD. The implications of this substantial occupational contribution to COPD must be considered in research planning, in public policy decision-making, and in clinical practice.

Journal Article↗

Defective production of soluble HLA-G molecules by peripheral blood monocytes in patients with asthma.

BACKGROUND: HLA-G, a human nonclassic MHC class I molecule, is responsible for complex immunoinhibitory functions. HLA-G is expressed as membrane-bound and is secreted as soluble molecules by the peripheral blood CD14+ monocytes activated by IL-10. OBJECTIVE: It has been reported that LPS stimulation induces IL-10 production by PBMCs and that IL-10 levels are reduced in patients with severe asthma compared with patients with mild asthma and healthy subjects. The study was designed to investigate whether this impaired IL-10 production can affect the expression and the secretion of soluble HLA-G (sHLA-G)-1/HLA-G5 molecules. METHODS: We investigated the production of sHLA-G1/HLA-G5 and IL-10 by specific ELISAs in the culture supernatants of LPS-activated PBMCs from 24 healthy subjects and 20 patients with moderate to severe persistent asthma. RESULTS: LPS stimulation induced the secretion of IL-10 and sHLA-G1/HLA-G5 molecules in all healthy subjects, whereas in patients with asthma, the levels of IL-10 were significantly lower (P < .001) and the number of cultures exhibiting detectable sHLA-G1/HLA-G5 was reduced (7/20; P < .001). The addition of exogenous IL-10 to LPS-stimulated PBMCs from patients with asthma restored normal sHLA-G1/HLA-G5 production. CONCLUSION: Our data suggest that a specific deficit of IL-10 secretion in patients with asthma could prevent the normal production of sHLA-G1/HLA-G5 molecules. The reduction of immunosuppressive activity mediated by HLA-G could in turn contribute to the persistence of chronic airway inflammation in asthma.

Adult↗

Sputum substance P and neurokinin A are reduced during exacerbations of chronic obstructive pulmonary disease.

Involvement of tachykinins in airway inflammation has been demonstrated in animal models, but evidence in humans is sparse. The aim of this study was to quantify the levels of substance P and neurokinin A in induced sputum of patients with chronic obstructive pulmonary disease (COPD) and to compare them with the levels in smokers with normal lung function and healthy nonsmokers. Content of tackykinins was measured in 12 sputum samples collected during stable condition and nine sputum samples collected during exacerbations from 13 COPD patients, in eight sputum samples from smokers with normal lung function and in nine from healthy nonsmokers. Patients with COPD exacerbations had a lower sputum content of substance P compared with the other 3 groups (p<0.05). No differences were found between patients with stable COPD, smokers with normal lung function, and nonsmokers. Sputum levels of neurokinin A were trending in the same direction of substance P, but the significant difference was reached for the paired sputum samples collected from the same COPD patients (n=8) during exacerbation and in stable condition. COPD exacerbations are associated with a reduced sputum content of substance P and neurokinin A. These tackykinins might be involved in COPD exacerbations.

Aged↗

Asthma induced by isocyanates: a model of IgE-independent asthma.

Developments in the understanding of causes and natural history of asthma induced by isocyanates may allow improved preventive strategies for occupational asthma (OA), and may also lead to improved understanding of mechanisms involved in IgE-independent nonoccupational asthma. Studies of genetic markers in OA induced by isocyanates suggest that HLA class II genes, glutathione S-transferase and NAT1 genotypes may predispose to development of this type of OA. Specific IgE antibodies against isocyanates are not always found in subjects with OA caused by isocyanates, leading most researchers to consider this type of OA, as a model of IgE-independent asthma. Evidence for cell-mediated immunity in OA induced by isocyanates has been provided by bronchoalveolar lavage, bronchial biopsy and induced sputum studies. The pathology of this type of asthma is similar to that of nonoccupational asthma, with cells such as eosinophils and T lymphocytes that exhibit signs of activation, and with thickening of the reticular layer of the basement membrane. Animal studies have shown that isocyanate asthma is driven primarily by CD4+ T cells and is dependent upon the expression of Th2 cytokines. However, animal models are not always reflective of human responses. OA induced by isocyanates similarly to nonoccupational asthma, is a multifactorial condition, and it is likely that complex gene-environment interactions play a role. Better understanding of these interactions is important for affected workers, and also has potential relevance for nonoccupational asthma.

Animals↗

Occupational asthma.

Occupational asthma (OA) is one of the most common forms of occupational lung disease in many industrialized countries, having been implicated in 9 to 15% of adult-onset asthma. Work-related asthma includes: 1. immunologic OA, characterized by a latency period before the onset of symptoms; 2. nonimmunologic OA, which occurs after single or multiple exposures to high concentrations of irritants; 3. work-aggravated asthma, which is pre-existing or concurrent asthma exacerbated by workplace exposures; and 4. variant syndromes. OA is important to recognize clinically, because it has serious medical and socioeconomic consequences. Diagnosis of OA should be confirmed by objective testing early after its onset. Removal of the worker from exposure to the causal agent and early treatment with anti-inflammatory drugs lead to a better outcome. Assessment of the work environment and identification of host factors may provide us with useful information about the mechanisms involved in OA. Another issue concerns strategies for preventing OA which should be implemented.

Allergens↗

[Lung cancer in a female non-smoker with occupational exposure to asbestos: a case report].

BACKGROUND: Until recently, asbestos was widely used in a variety of industrial processes. Workers exposed to asbestos may develop lung and pleural diseases such as asbestosis, lung cancer, benign pleural effusion, pleural plaques and mesothelioma. OBJECTIVE: To describe a clinical case of lung cancer in a female non-smoker with occupational exposure to asbestos. METHODS: The clinical and occupational history was based on the information kindly provided by the Occupational Unit of the National Health Service and on the case history of a hospital admittance in 2001, when the patient underwent surgery for lung cancer. RESULTS: The patient worked for 6 years in an asbestos manufacturing industry where she was exposed to high concentrations of asbestos, and then worked for 14 years in a sugar refinery only during the summer. She had benign pleural effusion, pleural plaques, asbestosis and lung cancer. CONCLUSIONS: We concluded that a six-year exposure to high doses of asbestos may induce lung cancer and asbestosis in a female non-smoker.

Asbestos↗