Advances in environmental and occupational disorders

The effect of Nigella sativa alone, and in combination with dexamethasone, on tracheal muscle responsiveness and lung inflammation in sulfur mustard exposed guinea pigs

ETHNOMEDICAL RELEVANCE: The anti-inflammatory activity of both systemic and local administrations of essential oil from Nigella sativa L. has been shown.

AIM OF THE STUDY

Therefore, the effect of Nigella sativa on tracheal responsiveness (TR) and lung inflammation of sulfur mustard (SM) exposed guinea pigs was examined.

MATERIALS AND METHODS

Guinea pigs were exposed to diluent solution (control group), inhaled SM (SME group), SME treated with Nigella sativa (SME+N), SME treated with dexamethasone (SME+D) and SME treated with both drugs (SME+N+D), (n=7 for each group). TR to methacholine, total white blood cell (WBC) and differential WBC count of lung lavage, and serum cytokines were measured 14 days post-exposure.

RESULTS

The values of TR, eosinophil, monocyte, lymphocyte, interleukine-4 (IL-4) and interferon gamma (IFN-γ) of SME group were significantly higher than those of controls (p<0.05 to p<0.001). The TR in SME+N, SME+D and SME+N+D was significantly lower compared to that of SME group (p<0.01 for all cases). The percentage of eosinophil in SME+D, and the percentage of monocyte in SME+N+D (p<0.05 to p<0.01) were significantly lower than those in SME group. The neutrophil number was decreased in SME+N and SME+N+D groups compared to SME animals (p<0.05 to p<0.01). IL-4 levels in serum of SME+N (p<0.01), SME+D (p<0.05), SME+N+D (p<0.01) and IFN-γ in SME+N (p<0.05) were greater than those in SME animals.

CONCLUSIONS

These results showed a preventive effect of Nigella sativa on TR and lung inflammation of SM exposed guinea pigs.

Candida soluble cell wall beta-glucan facilitates ovalbumin-induced allergic airway inflammation in mice: Possible role of antigen-presenting cells

BACKGROUND

Although fungi have been implicated as initiating/deteriorating factors for allergic asthma, their contributing components have not been fully elucidated. We previously isolated soluble beta-glucan from Candida albicans (CSBG) (Ohno et al., 2007). In the present study, the effects of CSBG exposure on airway immunopathology in the presence or absence of other immunogenic allergen was investigated in vivo, and their cellular mechanisms were analyzed both in vivo and in vitro.

METHODS

In vivo, ICR mice were divided into 4 experimental groups: vehicle, CSBG (25 microg/animal), ovalbumin (OVA: 2 microg/animal), and CSBG + OVA were repeatedly administered intratracheally. The bronchoalveolar lavage cellular profile, lung histology, levels of cytokines and chemokines in the lung homogenates, the expression pattern of antigen-presenting cell (APC)-related molecules in the lung digests, and serum immunoglobulin values were studied. In vitro, the impacts of CSBG (0-12.5 microg/ml) on the phenotype and function of immune cells such as splenocytes and bone marrow-derived dendritic cells (BMDCs) were evaluated in terms of cell proliferation, the surface expression of APC-related molecules, and OVA-mediated T-cell proliferating activity.

RESULTS

In vivo, repeated pulmonary exposure to CSBG induced neutrophilic airway inflammation in the absence of OVA, and markedly exacerbated OVA-related eosinophilic airway inflammation with mucus metaplasia in mice, which was concomitant with the amplified lung expression of Th2 cytokines and IL-17A and chemokines related to allergic response. Exposure to CSBG plus OVA increased the number of cells bearing MHC class II with or without CD80 in the lung compared to that of others. In vitro, CSBG significantly augmented splenocyte proliferation in the presence or absence of OVA. Further, CSBG increased the expression of APC-related molecules such as CD80, CD86, and DEC205 on BMDCs and amplified OVA-mediated T-cell proliferation through BMDCs.

CONCLUSION

CSBG potentiates allergic airway inflammation with maladaptive Th immunity, and this potentiation was associated with the enhanced activation of APCs including DC.

[Tobacco and morphology: pulmonary diseases]

Tobacco is implicated in multisystemic carcinogenesis through more than fifty identified carcinogenic metabolites that produce mutations responsible for alterations in cell cycle, immune response and endocrine regulation. Is one of nine risk factors identified in one third of cancer deaths together with obesity, sedentary, alcohol consumption, sexual promiscuity, drug addiction, and open and closed air contamination. Answering for cardiovascular diseases as the first cause of death in civilized world, tobacco is also pointed as the major factor implicated in the development of COPD (chronic obstructive pulmonary disease), RB-ILD (respiratory bronchiolitis and interstitial lung disease), DIP (desquamative interstitial pneumonia), bronchiolitis and bronchiolocentric interstitial fibrosis, Langerhans cells histiocytosis, eosinophilic pneumonia, sarcoidosis, epidermoid metaplasia in respiratory epithelium and lung cancer. The chronic tobacco induced inflammatory state is the basis for the acquisition of genetic alterations dependent on the tobacco contaminants.

Airway hyperresponsiveness to methacholine in chemical warfare victims

BACKGROUND

The lung is one of the most exposable organs to chemical warfare agents such as sulfur mustard gas. Pulmonary complications as a result of this gas range from severe bronchial stenosis to mild or no symptoms. Airway hyperresponsiveness (AHR) which is usually assessed as response to inhaled methacholine is the most characteristic feature of asthma. AHR is reported in chronic obstructive pulmonary disease patients and smokers, and may also show in chemical warfare victims. However, there are little reports regarding AHR in chemical warfare victims.

OBJECTIVE

Therefore, in this study, airway responsiveness to methacholine in victims of chemical warfare was examined.

METHODS

The threshold concentrations of inhaled methacholine required for a 20% change in forced expiratory flow in 1 s (FEV1; PC20) or a 35% change in specific airway conductance (PC35) were measured in 15 chemical war victims and 15 normal control subjects.

RESULTS

In 10 out of 15 chemical warfare victims (two thirds), PC20 and PC35 methacholine could be measured and subjects were called responders. AHR to methacholine in responder chemical war victims (PC20 = 0.41 and PC35 = 0.82 g/l) was significantly lower than in normal subjects (PC20 = 5.69 and PC35 = 4.60 g/l, p < 0.001 for both cases). There was a significant correlation between FEV1 and PC20 methacholine (r = 0.688, p < 0.001). The correlations between PC20 and PC35 were statistically significant as well (r = 0.856, p < 0.001).

CONCLUSION

Results showed increased airway responsiveness of most chemical warfare victims to methacholine which correlated with the FEV1 value and which may be related to chronic airway inflammation or irreversible airway changes.

Differential expression of allergens on the internal and external surfaces of latex surgical gloves

BACKGROUND

Differences in latex allergen sensitization profiles have been described between children undergoing repeated surgical interventions and health care workers. The purpose of this study was to determine whether such sensitization profiles are associated with differences in the expression of latex allergen between the internal and external surfaces of surgical gloves.

METHODS

Extracts were obtained from whole surgical gloves as well as from their external and internal surfaces. The extracts were centrifuged, filtered, concentrated, dialyzed and lyophilized. The protein profile of the extracts was analyzed using hydrophobic interaction chromatography (HIC) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immunoblotting was performed using sera from two patients with confirmed latex allergy. Latex recombinant allergen-specific IgE in these two patients was determined using a fluorescence enzyme immunoassay (FEIA) method. Latex allergen quantification was determined on both glove surfaces using an ELISA method.

RESULTS

HIC and SDS-PAGE showed qualitative and quantitative differences in proteins between the internal and external glove surfaces, with the former being much richer in proteins. Immunoblotting of glove extracts using sera from two latex-allergic health workers showed differences between glove surface extracts. ELISA quantification of latex allergens demonstrated that the internal glove surface had high amounts of Hev b 5 and Hev b 6.02 whereas the external surface showed Hev b 1, Hev b 3, and Hev b 6.02.

CONCLUSIONS

Our results reveal substantial differences in the composition of latex allergen profiles between the internal and external surfaces of surgical latex gloves, which may suggest a relationship between latex allergen localization and sensitization routes in different risk groups.

6. Asthma: Factors underlying inception, exacerbation, and disease progression

Asthma is a heterogeneous disorder that is characterized by variable airflow obstruction, airway inflammation and hyperresponsiveness, and reversibility either spontaneously or as a result of treatment. Multiple causes no doubt exist for both its inception and symptom exacerbation once the disease is established. Factors underlying inception can range from viral respiratory tract infections in infancy to occupational exposures in adults. Factors underlying asthma exacerbations include allergen exposure in sensitized individuals, viral infections, exercise, irritants, and ingestion of nonsteroidal anti-inflammatory agents among others. Exacerbating factors might include one or all of these exposures and vary both among and within patients. Asthma treatment is determined to a large extent after an assessment of severity, which can be variable over time and assessed in 2 domains: impairment (current) and risk (long-term consequences). Unfortunately, despite the availability of effective therapies, suboptimal asthma control exists in many patients on a worldwide basis. The future development of novel therapies and treatment paradigms should address these disparities.

Occupational asthma

Substantial epidemiologic and clinical evidence indicates that agents inhaled at work can induce asthma. In industrialized countries, occupational factors have been implicated in 9 to 15% of all cases of adult asthma. Work-related asthma includes (1) immunologic occupational asthma (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 irritant materials; (3) work-aggravated asthma, which is preexisting or concurrent asthma exacerbated by workplace exposures; and (4) variant syndromes. Assessment of the work environment has improved, making it possible to measure concentrations of several high- and low-molecular-weight agents in the workplace. The identification of host factors, polymorphisms, and candidate genes associated with OA is in progress and may improve our understanding of mechanisms involved in OA. A reliable diagnosis of OA should be confirmed by objective testing early after its onset. Removal of the worker from exposure to the causal agent and treatment with inhaled glucocorticoids lead to a better outcome. Finally, strategies for preventing OA should be implemented and their cost-effectiveness examined.

Latex allergy: diagnosis and management

Latex allergy is an IgE-mediated immediate hypersensitivity response to natural rubber latex (NRL) protein with a variety of clinical signs ranging from contact urticaria, angioedema, asthma, and anaphylaxis. Major allergens include dipped latex products such as gloves and balloons. In highest risk for NRL allergy are patients with spina bifida, but health care workers and others who wear latex gloves are also at risk. NRL allergic patients may also react to fruits/foods, especially banana, kiwi, and avocado. Diagnosis is made by a positive latex RAST and/or skin prick test or challenge test to NRL. Allergen avoidance and substitution and the use of latex-safe devices including synthetic gloves (vinyl, synthetic polyisoprene, neoprene, nitrile, block polymers, or polyurethane) are essential for the affected patient. Accommodation in the workplace may include the use of powder-free, low-allergen NRL gloves or synthetic gloves. These preventive measures have significantly reduced the prevalence of reported reactions to NRL. Hyposensitization is not yet feasible.

Respiratory health consequences of environmental tobacco smoke

Over the last several decades there has been a growing interest in examining the health consequences of environmental tobacco smoke (ETS). As a result of a wide body of research, ETS is now considered an unacceptable and entirely preventable public health hazard, and public policy increasingly discourages the presence of tobacco smoke in the public domain. This article provides an overview of the composition of ETS and the major diseases and disorders strongly linked to ETS, emphasizing the effects of ETS on pulmonary function, asthma, and lung cancer.

Clinical phenotypes of asthma

PURPOSE OF REVIEW

Asthma is a phenotypically heterogeneous disorder and, over the years, many different clinical subtypes of asthma have been described. A precise definition of asthma phenotypes is now becoming more and more important, not only for a better understanding of pathophysiologic mechanisms, but in particular to ascertain the specific genes associated with these phenotypes.

RECENT FINDINGS

In children, three asthma phenotypes are now well defined: transient infant wheezing, nonatopic wheezing of the toddler, and IgE-mediated wheezing/asthma. Recently, a fourth phenotype, late-onset childhood asthma has been added to this list. In adults, asthma persisting from childhood into adulthood should be distinguished from asthma starting in adulthood. The phenotypes of adult-onset asthma are still poorly defined. Until now, phenotypic classification has been based primarily on etiologic factors (eg, aspirin sensitivity, persistent respiratory infections, occupational factors, or toxic exposures) or clinical characteristics of the disease (eg, mild, severe, brittle, near fatal, with fixed airflow obstruction, steroid resistant). Novel noninvasive techniques to assess the type and severity of airway inflammation and dysfunction are increasingly used to identify better the different phenotypes.

SUMMARY

The classic phenotype of IgE-mediated asthma starting in childhood is now clearly defined. However, many other phenotypes of asthma in childhood as well in adulthood are being recognized. In particular, asthma starting in adulthood and noneosinophilic asthma constitute an important part of the adult asthma population, and are still poorly defined. A precise definition of these asthma phenotypes is urgently needed because they are likely to be associated with different genotypes, responses to treatment, and prognoses.