Secondhand smoke exposure in school children in Malta assessed through urinary biomarkers.

School children may be exposed to secondhand smoke (SHS) either at home, in transit or in social gatherings permitting smoking in their presence. Questionnaires about SHS often underestimate prevalence and extent of exposure. A more accurate tool is the use of biomarkers such as cotinine (COT) and trans-3'-hydrocycotinine (3HC) as biomarkers of SHS exposure, alongside 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a reduction product in the body of the tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), both potent carcinogens. We measured urinary COT, 3HC and total NNAL using sensitive and specific high-performance LC-MS/MS methods. The limit of quantification (LOQ) for each assay were 0.05 ng/mL, 0.1 ng/mL and 0.25 pg/mL respectively. The aim of this study was to evaluate the exposure to SHS of school children (9-11 years), from five public schools in the island of Malta, from questionnaire information about smoking at home and verify it by urinary biomarker data of COT, 3HC and NNAL. These biomarkers were measurable in 99.4%, 95.4% and 98.3% of the participating children respectively. From the children reporting smoking at home, 11% had a history of asthma and had COT, 3HC and NNAL geometric mean concentrations double compared to the non-asthmatic group. In has been confirmed that non-smokers exposed to SHS and THS have a higher NNAL/COT ratio than the group identified as smokers according to specific and defined COT threshold levels (despite the fact that a priori, the entire study group was composed of non-smokers). The implication of high measured levels of urinary NNAL in children should be of concern given its potency. A main effects multifactor ANOVA model was developed and the children's house and school locations and the smoking frequency were statistically significant to predict the levels of the three metabolites. For 3HC only, the status of the employment of the mother was also an important predictor.

An unusual cause of chest pain in a young man: bronchogenic cysts and their cardiac manifestations.

We report a case of a 24-year-old man who presented with chest pain and electrocardiographic evidence of myocardial ischaemia. An abnormal structure located behind the heart on the urgent transthoracic echocardiogram and a computed tomography scan of the mediastinum led to prompt surgery with eventual resection of the lesion. The histology revealed fragments of connective tissue covered by squamous epithelium and ciliated epithelium, consistent with a bronchogenic cyst. The case study is accompanied by a literature review of the pathogenesis, diagnosis and management of bronchogenic cysts and their association with cardiac symptoms.

Global map of the prevalence of symptoms of rhinoconjunctivitis in children: The International Study of Asthma and Allergies in Childhood (ISAAC) Phase Three.

BACKGROUND: Phase One of the International Study of Asthma and Allergies in Childhood (ISAAC) measured the global patterns of prevalence and severity of symptoms of rhinoconjunctivitis in children in 1993-1997. METHODS: International Study of Asthma and Allergies in Childhood Phase Three was a cross-sectional survey performed 5-10 years after Phase One using the same methodology. Phase Three covered all of the major regions of the world and involved 1 059 053 children of 2 age groups from 236 centres in 98 countries. RESULTS: The average overall prevalence of current rhinoconjunctivitis symptoms was 14.6% for the 13- to 14-year old children (range 1.0-45%). Variation in the prevalence of severe rhinoconjunctivitis symptoms was observed between centres (range 0.0-5.1%) and regions (range 0.4% in western Europe to 2.3% in Africa), with the highest prevalence being observed mainly in the centres from middle and low income countries, particularly in Africa and Latin America. Co-morbidity with asthma and eczema varied from 1.6% in the Indian sub-continent to 4.7% in North America. For 6- to 7-year old children, the average prevalence of rhinoconjunctivitis symptoms was 8.5%, and large variations in symptom prevalence were also observed between regions, countries and centres. DISCUSSION: Wide global variations exist in the prevalence of current rhinoconjunctivitis symptoms, being higher in high vs low income countries, but the prevalence of severe symptoms was greater in less affluent countries. Co-morbidity with asthma is high particularly in Africa, North America and Oceania. This global map of symptom prevalence is of clinical importance for health professionals.

Tuberculosis notification and treatment outcome among migrant boat arrivals in Malta, 2007-2011.

The annual incidence of tuberculosis (TB) in Malta has remained low, at <20 per 100 000 population per year. However, TB notification among vulnerable groups is on the rise and is a matter of public health concern. We measured the TB notification rate, which ranged from 470 to 880/100 000 among migrant boat arrivals 1 year after arrival, highlighting the need to maintain high treatment success rates. Early case detection and high treatment success were observed due to post-arrival screening; however, the need for pragmatic, patient-friendly approaches that will encourage self-referral and access to treatment among migrant groups could play a significant role in preventing the re-emergence of TB in low-incidence settings.

Bronchial biopsy evidence for leukocyte infiltration and upregulation of leukocyte-endothelial cell adhesion molecules 6 hours after local allergen challenge of sensitized asthmatic airways.

We have examined the mucosal changes occurring in bronchial biopsies from six atopic asthmatics 5-6 h after local endobronchial allergen challenge and compared them with biopsies from saline-challenged segments from the same subjects at the same time point. All the subjects developed localized bronchoconstriction in the allergen-challenged segment and had a decrease in forced expiratory volume in 1 s (FEV1) (P < 0.01) and a decrease in their methacholine provocative concentration of agonist required to reduce FEV1 from baseline by 20% (P < 0.05) 24 h postchallenge. At 6 h we observed an increase in neutrophils (P = 0.03), eosinophils (P = 0.025), mast cells (P = 0.03), and CD3+ lymphocytes (P = 0.025), but not in CD4+ or CD8+ lymphocyte counts. We also detected an increase in endothelial intercellular adhesion molecule type 1 (P < 0.05) and E-selectin (P < 0.005), but not vascular cell adhesion molecule type 1 expression with a correlative increase in submucosal and epithelial LFA+ leucocytes (P < 0.01). Thus, in sensitized asthmatics, local endobronchial allergen instillation leads to an increased inflammatory cell infiltrate of the airway mucosa that involves upregulation of specific adhesion molecules expressed on the microvasculature.

Cardiac involvement and left ventricular failure in a patient with the Churg-Strauss syndrome.

The Churg-Strauss syndrome is characterised by a history of asthma and paranasal sinus disease, eosinophilia of more than 10 per cent, non-fixed pulmonary infiltrates on chest radiography and vasculitis which may affect multiple organ systems. The condition usually manifests in the 4th decade. We present a 21-year old female with a history of asthma since one year of age who developed symptoms and signs of pneumonia, a pulmonary infiltrate on chest radiography and eosinophilia. This was followed a few weeks later by vasculitis which affected the skin and myocardium and associated with a peripheral eosinophilia of more than 80%. Physical examination revealed palpable purpura and signs of left ventricular failure. Echocardiography confirmed significant diminution of left ventricular contractility. A rapid improvement was observed after steroid therapy. Echocardiography after two months showed normal left ventricular function. In this presentation we review the cardiac manifestations of the Churg-Strauss syndrome and its management.

Leucocyte-endothelial adhesion molecules and their role in bronchial asthma and allergic rhinitis.

Leucocyte-endothelial adhesion molecules are involved in the initial stages of the recruitment and migration of inflammatory leucocytes from the circulation to sites of inflammation. There is accumulating evidence for their involvement in the pathophysiology of airway mucosal allergic inflammation, such as that found in asthma and rhinitis. The best characterized adhesion molecule families are the integrins, the immunoglobulin supergene family and the selectins. This review article describes some of the characteristics and properties of these families. We also discuss the situations in which these adhesion molecules might be involved in inflammatory airway diseases, and how evidence for this role might lead to future modes of therapy for these common conditions.

Recognition of asthmatic symptoms in the pediatric age group.

Asthma produces substantial morbidity in childhood. Under-diagnosis may lead to inappropriate treatment and prolonged periods of illness and absence from school. The results of a recent International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire study in Malta showed a higher prevalence of wheezy symptoms in the Central North Region. The present study was carried out to test the null hypothesis that there is no correlation between potential exposure to pediatricians (measured as pediatric private clinics/1000 childhood population/week) and percentage of children aged 13-15 years of age responding positively in the questionnaire to having had wheezy symptoms. A significant, positive correlation was found between potential exposure to pediatricians and percentage of children aged 13-15 years responding positively to having had wheeze in the previous year (p=0.009). A negative correlation was also found for severity of asthma (>12 attacks in the previous 12 months) and potential exposure to pediatricians (p=0.01). This is the first report of potential exposure to pediatricians influencing the regional incidence of asthma on a national basis. This skew may be caused by the greater exposure of pediatricians to patients with severe forms of asthma in a hospital setting, and hence a higher index of suspicion for the milder forms of the disease. Asthma may be less severe in regions where there are a greater number of pediatricians because of recognition of the condition with appropriate treatment and/or prophylaxis.

Investigative use of fibreoptic bronchoscopy for local airway challenge in asthma.

Local airway challenge has advantages over inhalation bronchial challenge as the response of the airway can be restricted and directly observed. It has been safely performed in subjects with mild or moderate asthma, either by the direct instillation of challenge solution to the selected segmental airways via a bronchoscope, or delivered to an airway segment isolated with a double-balloon catheter. However, these techniques carry potential complications, such as generalized wheeze, and due care is required in selection of subjects. Most investigators have used the method for studying the airway events following allergen challenge. Others have studied the airway changes following challenge with non-allergen provocation agents, such as hypertonic saline, adenosine 5'-monophosphate and cold dry air. The method has helped to define changes in the inflammatory cells and mediators in relation to early and late airway responses to allergen. Similarly, study of airway events following local challenge with hypertonic solution has provided useful knowledge in understanding the mechanisms of exercise-induced asthma. With more experience and an improved margin of safety, it will be possible to study local changes in airway physiology following local airway challenge. Finally, the techniques also have potential use for studying the airway events following provocation with a wide range of agents of potential relevance to the pathogenesis of asthma.

The site of disruption of the bronchial epithelium in asthmatic and non-asthmatic subjects.

BACKGROUND: Attention has recently been focused on the basal cells of the tracheobronchial epithelium as the mechanism of anchorage of the tall columnar cells, which themselves do not appear to form hemidesmosomes with the basement membrane of the epithelium. Residual basal cells have been described as remaining attached to the basement membrane after epithelial denudation. This led this group to formulate the hypothesis that there may be a potential plane of cleavage between the basal cells and the overlying columnar cell layer within the bronchial epithelium, which becomes disrupted in asthma. METHODS: Bronchoalveolar lavage samples were obtained during bronchoscopy from eight patients with atopic asthma and four normal controls. Ultrathin sections of lavage cell pellets were examined by electron microscopy and the number of columnar and basal cells found in each epithelial cell cluster was counted. Cytocentrifuge preparations of the lavage samples from the same subjects were also examined for free epithelial cells and epithelial cell clusters. RESULTS: Electron microscopic examination of the cell pellets showed that basal cells were present in very small numbers in the epithelial clusters in all subjects (mean 0.03 (SE 0.02)/cluster) and the ratio of columnar cells to basal cells was far greater than was encountered in the intact bronchial epithelium (167 nu 4). The cytocentrifuge preparations showed an increased number of epithelial cell clusters and epithelial cells in the asthmatic patients. Although these clusters were similar in size in the two groups of subjects (6.3 nu 5.1 cells/cluster) the ratio of free epithelial cells to cells within the cluster was higher in the non-asthmatic subjects. CONCLUSIONS: It is proposed that shedding of epithelial cells occurs along a suprabasal plane and that there is a potential plane of cleavage between the suprabasal and the basal cell layers, which might be more vulnerable to the various insults.

Asthma, rhinitis and eczema in Maltese 13-15 year-old schoolchildren -- prevalence, severity and associated factors [ISAAC]. International Study of Asthma and Allergies in Childhood.

BACKGROUND: Allergic conditions, especially asthma, seem to be increasingly common the world over. The International Study of Asthma and Allergies in Childhood [ISAAC] was the first worldwide study carried out with standardized questionnaires in order to create a reliable global map of childhood allergy. OBJECTIVES: The Maltese Islands were one of the centres participating in this study and in this paper the data obtained from 4184 13-15 year olds from 22 state and three private schools [88.7% response rate], and also data obtained from some added 'local' questions addressed to the same children, are included. in order to evaluate the problem of allergic conditions in Maltese schoolchildren. RESULTS: 27.9% of the participants were wheezers 'ever' while 16% were current wheezers. Of the latter children 15.1% were experiencing nocturnal wheezing at least once a week and 22% had a wheezing episode severe enough to limit speech. Nasal problems were present in 52.7% of these teenagers and 47.4% of all respondents persisted with these symptoms up to the year of answering the questionnaire. Hayfever had been diagnosed in 32.3% of all the children. 12.8% of respondents had a recurring itchy rash suggestive of eczema for at least 6 months of their lives and 10% had it currently. This was slightly lower than the global mean, unlike the case of wheezing, which in Malta was more common than the world average, and rhinitis, for which we had the second highest cumulative prevalence rate in the world. Multiple variables such as gender, smoking, family history of atopy, pets, soft furnishings and living in busy roads affected the prevalence and severity of the allergic conditions studied. CONCLUSIONS: Allergic conditions are very common in Maltese schoolchildren and are causing a lot of hardship to these same youngsters. The results of this study should serve as a stimulus to try and decrease this suffering through better management of these conditions, measures to control possible detrimental factors and further research on asthma, allergic rhinitis and eczema.

The distribution of adhesive mechanisms in the normal bronchial epithelium.

The integrity of the bronchial epithelium is dependent on various adhesion mechanisms that serve to hold the composite structure of the epithelium together and anchor it to the underlying basement membrane. Using immunohistochemistry we wanted to map out a number of these junctional and non-junctional adhesion mechanisms in the normal human bronchial epithelium. The beta 1-associated integrin subunit alpha 2 was immunolocalized to all of the epithelial intercellular spaces, whilst alpha 6 and beta 4 were strongly evident at the basal cell layer basement membrane junction. The alpha 1 and alpha 5 integrin subunits were not detected anywhere in the epithelium. Monoclonal antibodies (MoAbs) to tight junction polypeptides and the E-cadherin, liver cell adhesion molecule (LCAM), immunolocalized to the apicolateral portions of the intercellular junctions between all neighbouring columnar cells, with LCAM extending further along the lateral cell membrane. Desmosomal protein (dp) 1 and 2 MoAbs gave a punctate pattern between all of the suprabasal cells, and exhibited the greatest intensity of staining at the junction between the columnar and basal cell layers. In conclusion, there is an organized distribution of adhesive mechanisms within the normal human bronchial epithelium, which may be targeted by the various insults which lead to epithelial shedding.

Cell adhesion molecules and the bronchial epithelium.

The bronchial epithelium is the major barrier between the host and the provoking antigens in bronchial asthma. Recent studies have indicated that the epithelium is a truly stratified structure, with the superficial columnar cells depending on the underlying basal cells for anchorage. Only columnar cells are shed into bronchial lavage fluid. The epithelium is more fragile in asthma and more cells are lost in clusters. Desmosomes appear to be the major structural adhesion mechanism at the plane of cleavage between the columnar cells and the basal cells. The alpha 6- and beta 4-integrins, which contribute to hemidesmosomes and anchor cells to the underlying basement membrane, are expressed solely by basal cells. The apical aspects of the columnar cells are sealed by tight and intermediate junctions. There is constitutive expression of ICAM-1 and E-selectin in the vasculature of the bronchial mucosa, and ICAM is also present within the epithelium. These findings indicate that the bronchial epithelium is a complex structure that, as a mucosal surface, has constitutive expression of inflammatory cell adhesion molecules to serve normal leukocyte traffic.

Ciliated cell damage in the bronchial epithelium of asthmatics and non-asthmatics.

The importance of bronchial epithelial shedding in the pathogenesis of asthma has been highlighted by many investigators as a potential mechanism for bronchial hyperresponsiveness. It has been suggested that this disruption is the result of cytotoxic injury leading to shedding of damaged cells. To investigate whether damaged ciliated epithelial cells can be detected within the bronchial mucosa, we used tannic acid which only permeates disrupted cellular membranes, as a marker of cell damage. Bronchial biopsies from seven asthmatic and six normal subjects, were processed in tannic acid prior to preparation and sectioning for electronmicroscopic examination. Ciliated epithelial cells staining darkly with tannic acid were seen to comprise a similar proportion of the intact portion of bronchial epithelium in both normals and asthmatics (medians 31% vs 40%). We suggest that ciliated epithelial cells are not shed from the bronchial mucosa immediately after damage and that mechanisms other than granulocyte-mediated cytotoxicity may account for epithelial disruption in asthma, possibly involving the selective damage or reduced expression of intraepithelial intercellular adhesion molecules.

Inflammatory and T-cell profile of asthmatic airways 6 hours after local allergen provocation.

T cells in the airways are considered to play a key role in orchestrating the inflammatory response of asthma through the elaboration of specific cytokines. Using flow cytometry we have investigated the T-cell response of sensitized asthmatic airways 6 h after local allergen provocation. Twelve subjects with atopic asthma underwent bronchoalveolar lavage (BAL) before and 6 h after local instillation of allergen into the right middle lobe (RML) and saline into the right upper lobe (RUL). Allergen challenge produced a significant 26% fall in FEV1, an increase in eosinophils in BAL at 6 h, and at 24 h an increase in methacholine responsiveness compatible with late-phase airway inflammation. When compared with saline challenge, allergen produced an overall decrease in the number of BAL lymphocytes from 21.3 +/- 2.8% to 16.0 +/- 3.08% of total cells but no change in the proportion of CD4+, CD8+, CD25+, or HLA-DR+ cells. Allergen provocation reduced the proportion of T cells expressing the beta 2 integrin lymphocyte functional antigen-1 (LFA-1) from 72.5 +/- 30 to 43.9 +/- 9.1 mean fluorescent units (p < 0.01) and a similar trend in intercellular adhesion molecule-1 (ICAM-1) (p = 0.08). These results indicate that late-phase inflammatory events 6 h after local allergen provocation involve the selective retention of airway T cells expressing specific cell adhesion molecules.

The effect of treatment with oral corticosteroids on asthma symptoms and airway inflammation.

To improve understanding of the mechanisms of action of oral corticosteroids in asthma, we have conducted a double-blind, placebo-controlled study with prednisolone (20 mg for 2 wk followed by 10 mg for 4 wk) or placebo in 14 and 13 atopic corticosteroid-naive asthmatic subjects, respectively. Before and after treatment subjects underwent bronchoscopy with bronchoalveolar lavage (BAL) and bronchial biopsy. Treatment with prednisolone, but not placebo, significantly reduced asthma symptoms (from mean +/- SEM total weekly score of 34 +/- 6.2 to 15.7 +/- 3.2, p = 0.02) and albuterol usage (from mean +/- SEM number of puffs/wk of 29.7 +/- 6.2 to 18.2 +/- 3.7, p = 0.01) and significantly increased FEV1 (from 89.8 +/- 4.4% to 99.3 +/- 4.1% of predicted, p = 0.03). There were no significant changes in inflammatory or epithelial cell counts, levels of T-cell activation or albumin concentration in BAL. However, immunohistochemistry of bronchial biopsies showed that in the submucosa prednisolone significantly decreased numbers of mast cells by 62% (from median 45 to 17/mm2, p = 0.01), eosinophils by 81% (from median 30.1 to 5.7/mm2, p = 0.004), and CD4+ T-cells by 68% (from median 64.6 to 18.5/mm2, p = 0.02). In the epithelium only the reduction in the numbers of eosinophils was significant (from median 1.1 to 0/mm of epithelium, p = 0.02). There were no significant changes in any cell counts in the subjects receiving placebo, and comparison of the changes between the treatment groups identified a significant prednisolone-related reduction in submucosal eosinophil and mast cell counts (p = 0.003 and 0.03, respectively). The temporal association between the clinical and physiologic improvement, and the correlation between the magnitude of change in CD4+ T-cell counts in the submucosa and increase in PC20 methacholine (rs = 0.60, p = 0.049) suggests that the reduction in airways inflammatory cell numbers underlies the clinical efficacy of oral corticosteroids.

Intercellular adhesion molecule-1 (ICAM-1) and endothelial leucocyte adhesion molecule-1 (ELAM-1) expression in the bronchial mucosa of normal and asthmatic subjects.

Bronchial lavage and biopsy studies suggest the involvement of eosinophils and T-lymphocytes in allergic inflammation in asthma. There is evidence suggesting that the expression of adhesion molecules on endothelial cells and of their receptors on leucocytes is involved in this process. To investigate these mechanisms we have obtained bronchial mucosal biopsies from 10 normal subjects and from 10 symptomatic atopic asthmatics. Six of the asthmatics were re-biopsied after 6 weeks of inhaled beclomethasone dipropionate (BDP) during which time their clinical response was monitored. Frozen sections were stained by the immunoperoxidase method using monoclonal antibody (MoAb) 6.5B5 to identify expression of intercellular adhesion molecule (ICAM-1) and MoAb 1.2B6 for endothelial leucocyte adhesion molecule (ELAM-1). Araldite-embedded sections were also stained for eosinophils using MoAb EG2 to identify eosinophilic cationic protein (ECP). A significant mucosal eosinophilia was apparent in the asthmatic but not in the normal biopsies. Immunostaining for ICAM-1 was observed in both the epithelium and endothelium and ELAM-1 in endothelium, with no significant differences being apparent between the asthmatic and normal subjects. Topical BDP markedly reduced the mucosal eosinophilia without affecting the expression of either adhesion molecule. Using this method, we conclude that there is basal expression of ICAM-1 and ELAM-1 in normal human bronchial mucosa, which is not significantly different from that in asthmatics, and that it is insensitive to suppression with corticosteroids at an inhaled dose that causes clinical improvement.