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1.
Environ Res ; 204(Pt D): 112405, 2022 03.
Article in English | MEDLINE | ID: mdl-34822856

ABSTRACT

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.


Subject(s)
Nitrosamines , Tobacco Smoke Pollution , Biomarkers/metabolism , Carcinogens/analysis , Child , Chromatography, Liquid , Cotinine/metabolism , Female , Humans , Malta , Tandem Mass Spectrometry , Tobacco Smoke Pollution/analysis
2.
Int J Tuberc Lung Dis ; 22(2): 194-196, 2018 02 01.
Article in English | MEDLINE | ID: mdl-29506616

ABSTRACT

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.


Subject(s)
Disease Notification/statistics & numerical data , Tuberculosis, Pulmonary/epidemiology , Adolescent , Adult , Africa/ethnology , Emigrants and Immigrants , Female , Humans , Male , Malta/epidemiology , Retrospective Studies , Socioeconomic Factors , Tuberculosis, Pulmonary/ethnology , Tuberculosis, Pulmonary/prevention & control , Young Adult
3.
J R Coll Physicians Edinb ; 40(1): 29-32, 2010 Mar.
Article in English | MEDLINE | ID: mdl-21125036

ABSTRACT

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.


Subject(s)
Bronchogenic Cyst/complications , Chest Pain/etiology , Adult , Bronchogenic Cyst/diagnostic imaging , Bronchogenic Cyst/surgery , Electrocardiography , Emergencies , Humans , Male , Myocardial Ischemia/diagnosis , Tomography, X-Ray Computed , Ultrasonography
4.
Allergy ; 64(1): 123-48, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19132975

ABSTRACT

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.


Subject(s)
Conjunctivitis, Allergic/epidemiology , Global Health , Rhinitis, Allergic, Perennial/epidemiology , Adolescent , Age Factors , Asthma , Child , Comorbidity , Cross-Sectional Studies , Eczema , Humans , Prevalence
5.
Pediatr Allergy Immunol ; 12(1): 49-53, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11251865

ABSTRACT

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.


Subject(s)
Asthma/epidemiology , Adolescent , Humans , Private Practice/statistics & numerical data , Recognition, Psychology/physiology , Respiratory Sounds/physiopathology , Surveys and Questionnaires
6.
Adv Exp Med Biol ; 455: 547-9, 1999.
Article in English | MEDLINE | ID: mdl-10599397

ABSTRACT

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.


Subject(s)
Churg-Strauss Syndrome/complications , Heart Diseases/etiology , Adult , Asthma/complications , Churg-Strauss Syndrome/drug therapy , Churg-Strauss Syndrome/physiopathology , Electrocardiography , Enalapril/therapeutic use , Female , Furosemide/therapeutic use , Heart Diseases/physiopathology , Heart Diseases/prevention & control , Humans , Immunosuppressive Agents/therapeutic use , Ventricular Function, Left
7.
J Allergy Clin Immunol ; 103(1 Pt 1): 125-38, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9893196

ABSTRACT

BACKGROUND: Little is known about the prevalence of atopic eczema outside Northern Europe. OBJECTIVES: We sought to describe the magnitude and variation in the prevalence of atopic eczema symptoms throughout the world. METHODS: A cross-sectional questionnaire survey was conducted on random samples of schoolchildren aged 6 to 7 years and 13 to 14 years from centers in 56 countries throughout the world. Those children with a positive response to being questioned about the presence of an itchy relapsing skin rash in the last 12 months that had affected their skin creases were considered to have atopic eczema. Children whose atopic eczema symptoms resulted in sleep disturbance for 1 or more nights per week were considered to have severe atopic eczema. RESULTS: Complete data was available for 256,410 children aged 6 to 7 years in 90 centers and 458,623 children aged 13 to 14 years in 153 centers. The prevalence range for symptoms of atopic eczema was from less than 2% in Iran to over 16% in Japan and Sweden in the 6 to 7 year age range and less than 1% in Albania to over 17% in Nigeria for the 13 to 14 year age range. Higher prevalences of atopic eczema symptoms were reported in Australasia and Northern Europe, and lower prevalences were reported in Eastern and Central Europe and Asia. Similar patterns were seen for symptoms of severe atopic eczema. CONCLUSIONS: Atopic eczema is a common health problem for children and adolescents throughout the world. Symptoms of atopic eczema exhibit wide variations in prevalence both within and between countries inhabited by similar ethnic groups, suggesting that environmental factors may be critical in determining disease expression. Studies that include objective skin examinations are required to confirm these findings.


Subject(s)
Asthma/epidemiology , Dermatitis, Atopic/epidemiology , Hypersensitivity/epidemiology , Adolescent , Child , Europe/epidemiology , Female , Humans , Male , Severity of Illness Index , Surveys and Questionnaires
8.
Clin Exp Allergy ; 28(9): 1089-99, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9761012

ABSTRACT

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.


Subject(s)
Asthma/epidemiology , Eczema/epidemiology , Rhinitis/epidemiology , Adolescent , Female , Global Health , Humans , Male , Malta/epidemiology , Prevalence , Risk Factors , Schools , Severity of Illness Index , Surveys and Questionnaires
9.
Am J Respir Crit Care Med ; 155(3): 826-32, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9117012

ABSTRACT

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.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Asthma/drug therapy , Bronchitis/drug therapy , Glucocorticoids/therapeutic use , Prednisolone/therapeutic use , Administration, Oral , Adolescent , Adult , Asthma/physiopathology , Bronchitis/pathology , Bronchitis/physiopathology , Bronchoalveolar Lavage , Bronchoscopy , Double-Blind Method , Forced Expiratory Volume , Humans , Leukocyte Count , Middle Aged , T-Lymphocytes/immunology , Treatment Outcome
10.
Pediatr Allergy Immunol ; 8(4): 161-76, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9553981

ABSTRACT

BACKGROUND: As part of the International Study of Asthma and Allergies in Childhood (ISAAC), prevalence surveys were conducted among representative samples of school children from locations in Europe, Asia, Africa, Australia, North and South America. SUBJECTS: 257,800 children aged 6-7 years from 91 centres in 38 countries, and 463,801 children aged 13-14 years from 155 centres in 56 countries. METHODS: Written symptom questionnaires were translated from English into the local language for self-completion by the 13-14-year-olds and completion by the parents of the 6-7-year-olds. Rhinitis was described as a problem with sneezing, or a runny, or blocked nose when you (your child) DID NOT have a cold or the flu. Additional questions were asked about rhinitis associated with itchy-watery eyes, interference with activities and a history of hay fever ever. RESULTS: The prevalence of rhinitis with itchy-watery eyes ("rhinoconjunctivitis") in the past year varied across centres from 0.8% to 14.9% in the 6-7-year-olds and from 1.4% to 39.7% in the 13-14-year-olds. Within each age group, the global pattern was broadly consistent across each of the symptom categories. In centres of higher prevalence there was great variability in the proportion of rhinoconjunctivitis labelled as hay fever. The lowest prevalences of rhinoconjunctivitis were found in parts of eastern Europe, south and central Asia. High prevalences were reported from centres in several regions. CONCLUSION: These results suggest substantial worldwide variations in the prevalence and labelling of symptoms of allergic rhinoconjunctivitis which require further study. These differences, if real, may offer important clues to environmental influences on allergy.


Subject(s)
Asthma/epidemiology , Rhinitis, Allergic, Perennial/epidemiology , Rhinitis, Allergic, Seasonal/epidemiology , Adolescent , Africa/epidemiology , Asia/epidemiology , Child , Europe/epidemiology , Humans , North America/epidemiology , Observer Variation , Prevalence , South America/epidemiology
11.
Eur Respir J ; 9(11): 2236-42, 1996 Nov.
Article in English | MEDLINE | ID: mdl-8947066

ABSTRACT

We have investigated the expression of cell surface markers and leucocyte cell adhesion molecules by immunohistochemistry in bronchial biopsies from 10 mild atopic asthmatics and 8 normal, nonatopic subjects. Significantly increased numbers of eosinophils (p<0.01) were evident in the bronchial submucosa of asthmatic subjects. In epithelium there were more CD44+ (p<0.02) and lymphocyte function-associated antigen-1 (LFA-1)+ (p<0.06) leucocytes in asthmatics than in normal subjects. Bronchial epithelial cells stained positively with anti-CD44 monoclonal antibodies (moAb) in both groups; however, when the staining was expressed as percentage of the total basement membrane, a considerable and highly significant increase was observed in the asthmatics (median 80 vs 22%, p=0.003). Few leucocytes were positive for very late activation antigen (VLA)-1, VLA-2 and VLA-4. The moAb for VLA-6 stained the basement membrane of the bronchial epithelium; while intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were constitutively expressed in endothelium. A positive correlation was found between LFA-1+ cells and activated eosinophils (EG2+) in the submucosa (p<0.005; r(s)=0.80). We conclude that even in mild asthma there is evidence of increased expression of cell surface ligands, and suggest that adhesive mechanisms play a role both in cell recruitment and disease activity.


Subject(s)
Asthma/metabolism , Bronchi/metabolism , Hyaluronan Receptors/analysis , Integrins/analysis , Adult , Asthma/pathology , Eosinophils , Epithelium/chemistry , Female , Humans , Immunohistochemistry , Integrin alpha1beta1 , Integrin alpha4beta1 , Integrin alpha6beta1 , Integrin beta1/analysis , Intercellular Adhesion Molecule-1/analysis , Leukocyte Count , Lymphocyte Function-Associated Antigen-1/analysis , Male , Middle Aged , Mucous Membrane/metabolism , Phenotype , Receptors, Collagen , Receptors, Lymphocyte Homing/analysis
12.
Am J Respir Crit Care Med ; 153(4 Pt 1): 1391-7, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8616571

ABSTRACT

Local endobronchial allergen challenge is being increasingly used to investigate the role of allergic inflammation in asthma. However, little information is available about the safety of this procedure and the changes induced in airway physiology. BAL and biopsy were performed at 10 min and at 4 to 6 h, or 24 h after segmental allergen challenge in 49 patients with atopic asthma. Two hours after challenge, FEV1 was reduced from 97.6 +/- 13.9 (mean +/- SD) to 83.4 +/- 21.7% predicted. FEV1 remained reduced at 4 to 6 h (87.7 +/- 20.4%), but it had nearly returned to baseline by 24 h (93.2 +/- 14.0%). When endobronchial challenge was combined with BAL and biopsy, the initial fall in FEV1 was slightly greater (from 101.8 +/- 14.2 to 78.5 +/- 13.6%). Bronchial responsiveness to methacholine was measured in 10 subjects, and it showed a twofold increase 24 h after local challenge and lavage. Significant changes in FEV1 and methacholine PC20 were still detectable 72 h after challenge. Widespread wheezing occurred in 29% of the subjects, but none of the them had to be admitted to hospital. We conclude that local endobronchial allergen challenge, although producing measurable changes in airway physiology, is in general well tolerated and is an acceptable method to investigate airway pathophysiologic processes in patients with mild to moderate asthma.


Subject(s)
Asthma/physiopathology , Bronchial Provocation Tests , Adult , Biopsy , Bronchi/pathology , Bronchial Provocation Tests/methods , Bronchoalveolar Lavage , Bronchoscopy , Female , Forced Expiratory Volume , Humans , Male , Retrospective Studies , Safety
13.
Am J Respir Crit Care Med ; 153(2): 515-20, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8564090

ABSTRACT

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.


Subject(s)
Allergens , Asthma/immunology , Bronchi/immunology , T-Lymphocyte Subsets , Adult , Antigens, CD/analysis , Asthma/pathology , Asthma/physiopathology , Bronchi/pathology , Bronchial Provocation Tests , Bronchoalveolar Lavage Fluid/immunology , Bronchoscopy , CD4 Lymphocyte Count , CD8-Positive T-Lymphocytes , Cell Count , Female , Flow Cytometry , Forced Expiratory Volume , HLA-DR Antigens/analysis , Humans , Inflammation , Intercellular Adhesion Molecule-1/metabolism , Lymphocyte Count , Male , T-Lymphocytes/metabolism
16.
Am J Respir Crit Care Med ; 149(5): 1149-52, 1994 May.
Article in English | MEDLINE | ID: mdl-7513593

ABSTRACT

There is increasing evidence that leukocyte-endothelial adhesion molecules are important in inflammatory airway disease because of their involvement in the primary steps of entrapment and migration of leukocytes to the site of inflammation. Recently, circulating forms of these adhesion molecules have been described, although their origin, fate, and function are still unknown. We have used an antigen capture ELISA to measure the concentrations of circulating intercellular adhesion molecule-1 (cICAM-1), E-selectin (cE-selectin), and vascular cell adhesion molecule-1 (cVCAM-1) in the peripheral blood of 13 atopic and 16 non-atopic normal subjects, 29 patients with stable asthma, and inpatients with acute asthma on Day 1 (n = 38), Day 3 (n = 29), and Day 28 (n = 13) of an asthmatic episode. Circulating ICAM-1 and E-selectin levels were significantly raised in acute asthma on all three study days when compared with those observed in stable asthma, atopic normal, or nonatopic normal volunteers with no significant differences among the latter three groups. Circulating VCAM-1 was not significantly increased in any of the groups studied. There were no correlations among the concentrations of these three circulating adhesion molecules. The elevated concentrations of cICAM-1 and cE-selectin in acute asthma may reflect the extensive inflammatory response occurring in the airways during acute exacerbations of the disease with airway obstruction. It is possible that the cytokine and mediator profiles in acute asthma lead to the preferential synthesis and expression of these two circulating adhesion molecules in comparison with cVCAM-1.


Subject(s)
Asthma/blood , Cell Adhesion Molecules/blood , Acute Disease , Adult , E-Selectin , Enzyme-Linked Immunosorbent Assay , Female , Humans , Intercellular Adhesion Molecule-1 , Male , Vascular Cell Adhesion Molecule-1
17.
Am J Respir Cell Mol Biol ; 10(5): 471-80, 1994 May.
Article in English | MEDLINE | ID: mdl-8179909

ABSTRACT

Asthma is characterized by the presence of an inflammatory cell infiltrate in the bronchial mucosa consisting of activated mast cells, eosinophils, and T cells. Several cytokines are considered to play a pivotal role in this response, particularly interleukin (IL)-4, IL-5, IL-6, and tumor necrosis factor-alpha (TNF-alpha). In this study, we have used immunohistochemistry applied to thin glycol methacrylate sections of bronchial mucosal biopsies to define the cellular provenance of these cytokines in normal and asthmatic airways. Both the asthmatic and normal mucosa contained numerous cells staining positively for all four cytokines, with the majority identified as mast cells by their tryptase content. Eosinophils also accounted for some IL-5 immunostaining in the asthmatic biopsies. By using two monoclonal antibodies directed to different epitopes of IL-4, we provide tentative evidence for enhanced IL-4 secretion in asthma. Similarly, a sevenfold increase in the number of mast cells staining for TNF-alpha in the asthmatic biopsies suggests that this cytokine is also up-regulated in this disease. These findings clearly identify human mast cells as a source of IL-4, IL-5, IL-6, and TNF-alpha and add to the view that, along with T cells, mast cells may play an important role in initiating and maintaining the inflammatory response in asthma.


Subject(s)
Asthma/immunology , Bronchi/immunology , Interleukins/metabolism , Mast Cells/metabolism , Tumor Necrosis Factor-alpha/metabolism , Adult , Bronchi/physiopathology , Eosinophils/immunology , Female , Humans , Immunohistochemistry , Male , Mucous Membrane/immunology
18.
J Clin Invest ; 93(4): 1411-21, 1994 Apr.
Article in English | MEDLINE | ID: mdl-7512980

ABSTRACT

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.


Subject(s)
Allergens/immunology , Asthma/pathology , Bronchi/pathology , Cell Adhesion Molecules/analysis , Leukocytes/pathology , Adult , Asthma/immunology , Asthma/metabolism , Biopsy , Bronchi/ultrastructure , E-Selectin , Female , Humans , Intercellular Adhesion Molecule-1 , Lymphocyte Function-Associated Antigen-1/analysis , Male , Time Factors , Up-Regulation , Vascular Cell Adhesion Molecule-1
19.
Am J Respir Crit Care Med ; 149(4 Pt 1): 1012-9, 1994 Apr.
Article in English | MEDLINE | ID: mdl-8143036

ABSTRACT

Hypertonicity of airway lining fluid has been suggested as the stimulus for bronchoconstriction in exercise-induced asthma. We explored the airway effects of delivering a direct hypertonic stimulus to asthmatic airways via a fiberoptic bronchoscope, comparing hypertonic saline challenge by direct instillation with local aerosol delivery. A group of 18 asthmatic subjects responsive to inhaled hypertonic saline with a history of EIA were studied; the first 9 subjects received local challenge with hypertonic saline by direct instillation, and the next 9 subjects were challenged by local aerosol delivery. A control challenge with isotonic saline by either instillation or aerosol was performed at a same bronchoscopy. Local challenge with hypertonic saline by aerosol delivery was found to be more effective in inducing local bronchoconstriction (8 of 9 subjects) than instillation (2 of 6 subjects). Paired BAL fluid samples and bronchial biopsies were obtained in total of 11 and 9 subjects, respectively. Local challenge with hypertonic saline either by instillation or aerosol produced no significant change in histamine, tryptase, or PGD2 levels in BAL fluid or mast cell numbers and degranulation in bronchial biopsies. A significant correlation was observed between histamine levels in BAL fluid and airway responsiveness to inhaled hypertonic saline (rs = -0.59, p < 0.05). Bronchial biopsies showed evidence of extensive epithelial damage; however, this was not related to airway responsiveness to inhaled hypertonic saline.


Subject(s)
Asthma, Exercise-Induced/diagnosis , Bronchi/drug effects , Saline Solution, Hypertonic , Adolescent , Adult , Aerosols , Asthma, Exercise-Induced/metabolism , Asthma, Exercise-Induced/pathology , Biopsy , Bronchi/ultrastructure , Bronchial Provocation Tests/methods , Bronchial Provocation Tests/statistics & numerical data , Bronchoalveolar Lavage Fluid/chemistry , Bronchoalveolar Lavage Fluid/cytology , Bronchoscopy/methods , Female , Fiber Optic Technology , Humans , Male , Saline Solution, Hypertonic/administration & dosage
20.
Am Rev Respir Dis ; 148(6 Pt 2): S79-82, 1993 Dec.
Article in English | MEDLINE | ID: mdl-8256927

ABSTRACT

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.


Subject(s)
Bronchi/metabolism , Cell Adhesion Molecules/metabolism , Asthma/metabolism , Asthma/pathology , Biopsy , Bronchi/ultrastructure , Bronchoalveolar Lavage Fluid/cytology , Epithelium/metabolism , Epithelium/ultrastructure , Fluorescent Antibody Technique , Humans , Immunohistochemistry , Microscopy, Electron
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