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F Thien

Publications and source records attributed to F Thien.

30 records · Page 2Linked to original sources
PubMed1998

Differential regulation of allergen-specific T(H2)- but not T(H1)-type responses by alveolar macrophages in atopic asthma.

BACKGROUND AND OBJECTIVE: Previous studies have suggested that quantitative differences in TH2-type cytokine responses in the airways are of particular importance in the pathogenesis of asthma. In this study we investigated whether alveolar macrophages (AMs) and peripheral blood monocytes (PMNs) are able to significantly influence the profiles of allergen-induced TH1 (IFN-gamma) and TH2 (IL-4 and IL-5) cytokine production by CD4+ T cells in atopic asthmatic subjects versus atopic nonasthmatic subjects and nonatopic normal subjects. METHODS: Peripheral blood CD4+ T cells were cultured alone or cocultured with either PMNs or AMs with allergen stimulation in the 3 groups. RESULTS: Although allergen stimulation did not change TH1 or TH2 cytokine responses in cultures of CD4+ T cells alone, the addition of PMNs to the cultures induced a significant increase in production of IL-4, IL-5, and IFN-gamma (P < .01 or P < .001) in atopic asthmatic subjects and atopic nonasthmatic subjects. However, PMNs induced a significant increase for IFN-gamma (P < .05) only in normal subjects. AMs from atopic asthmatic subjects significantly enhanced production of all 3 cytokines (P < .01 or P < .001), whereas the AMs from atopic nonasthmatic subjects significantly increased only production of IL-4 (P < .01) and IFN-gamma (P < .05) but not IL-5. Furthermore, IL-4 (P = .066) and IL-5 (P < .01) production in allergen-stimulated AM-CD4+ cell cocultures was higher in atopic asthmatic subjects but significantly lower in atopic nonasthmatic subjects (P < .05) as compared with the PMN-cocultures. For IFN-gamma, no difference was found between the AM and PMN cocultures in either atopic group. Allergen-stimulated IL-5 production in coculture with both AMs and PMNs inversely correlated with both baseline FEV1 percent predicted and PD20 methacholine in atopic asthmatic subjects (P < .05, P < .01, or P < .001). CONCLUSION: These data suggest that AMs from atopic asthmatic subjects but not atopic nonasthmatic subjects, play a significant role in airway pathogenic immunity through enhancing TH2-type cytokine production.

Adolescent↗
PubMed1998

Do dairy products induce bronchoconstriction in adults with asthma?

BACKGROUND: Dairy products have often been implicated as a cause of exacerbation of asthma, but there is little scientific evidence to support this hypothesis. OBJECTIVE: We sought to determine whether dairy products induce bronchoconstriction in a group of adults with asthma. METHODS: Twenty subjects with asthma (13 women and 7 men) were recruited from respondents who had previously completed a food and asthma questionnaire. Ten subjects perceived that their asthma became worse with ingestion of dairy products (positive perceivers), whereas ten were negative perceivers. None of the subjects had positive skin prick test results with cow's milk. The study was a randomized, cross-over, double-blind, placebo-controlled trial. Subjects complied with a dairy-free diet throughout the study. The active challenge was a single-dose drink equivalent to 300 ml of cow's milk. A positive reaction was defined as a 15% reduction in both FEV1 and peak expiratory flow (PEF) on the active challenge day compared with results obtained at the same time on the placebo day. RESULTS: For both FEV1 and PEF there were no statistically significantly differences in group means between active challenge and placebo challenge, between sequence of administration, or between perceptions. Nine subjects showed FEV1 or PEF changes that were greater than 15% of baseline values: four patients showed changes after both active and placebo treatment; two after treatment with placebo only; and three after active treatment alone. Of the latter group, two subjects showed changes only in PEF, and when one of these subjects underwent a further detailed study, no asthmatic reaction could be demonstrated. CONCLUSION: It is unlikely that dairy products have a specific bronchoconstrictor effect in most patients with asthma, regardless of their perception.

Adolescent↗
PubMed1998

The effects of monosodium glutamate in adults with asthma who perceive themselves to be monosodium glutamate-intolerant.

BACKGROUND: Many previous clinical studies of food-induced asthma suffer from inadequate baseline or control data. A statistically valid, randomized, double-blind, placebo-controlled, monosodium glutamate (MSG)-challenge protocol was developed for identifying early and late asthmatic reactions in an individual. OBJECTIVE: We sought to determine whether MSG would induce bronchoconstriction in a group of adults with asthma who perceived that they were MSG sensitive. METHODS: Twelve subjects (seven women, mean age 35.3 years) with clinically documented asthma and a perception of MSG-induced asthma were recruited. FEV1 and peak expiratory flow data were obtained for 3 whole control days, as well as time-matched data for 3 separate challenge days (1 gm MSG, 5 gm MSG, and 5 gm lactose [placebo]). Opaque capsule challenges were given as a single dose in the morning after an overnight fast. Subjects complied with an elimination diet throughout the study. Nonspecific bronchial hyperresponsiveness was measured at baseline, after the control days, and at the conclusion of the challenges. Venous blood samples were taken at baseline and on each challenge day to determine soluble inflammatory marker (eosinophil cationic protein and tryptase) activity. RESULTS: No immediate or definite late asthmatic reactions occurred. One subject's FEV1 declined more than 15% on MSG challenge, but 95% confidence limits for the control-day spirometry showed that this decline was within her daily variation, hence the challenge was deemed to be negative. No significant changes in bronchial hyperresponsiveness or soluble inflammatory markers were found. CONCLUSIONS: MSG-induced asthma was not demonstrated in this study. This study highlighted the importance of adequate baseline and control data and indicated that such a rigorous protocol for individual assessment is feasible.

Adult↗
PubMed1997

Attendance at an asthma educational intervention: characteristics of participants and non-participants.

As part of an evaluation of the patient education component of the Australian Asthma Management plan, a randomized, controlled trial of asthma education was conducted in 1994/95 at the outpatient asthma and allergy clinic of The Alfred Hospital, a tertiary referral hospital in Melbourne, Australia. The objective of the study was to investigate which demographic and clinical characteristics were associated with attendance at asthma educational session. A total of 125 asthmatics aged over 16 years agreed to participate in the programme, and full compliance with the programme was 43.2%. Allocation to immediate, rather than delayed, education and age were the only significant predictors of attendance. Subjects randomized to the intervention were approximately three times more likely to attend than control subjects (OR = 3.3, 95% CI 1.5-7.3). Asthmatics over 60 years old were approximately six times more likely to attend (OR = 6.6, 95% CI 2.2-19.8) than the age group 16-30 years. The increasing trend in attendance across age categories was highly significant (P < 0.001). There was no relationship between attendance and gender, medication, atopy, smoking status or the physical accessibility of the hospital. Despite offering incentives and conducting the education sessions at subjects' preferred times, their compliance in attending sessions was poor. Over half of the asthmatics, who had expressed interest, failed to attend for their educational sessions. An alternative strategy is required to improve participation by young and employed asthmatics at hospital-based asthma education programmes.

Adolescent↗
PubMed1996

Patients' perceptions of food-induced asthma.

BACKGROUND: The influence of diet in asthma control remains unclear. However, there is likely to be a wide gap between patient perceptions and the probable actual role. Some 20-60% of people with asthma report food as a trigger factor while approximately 2.5% react to double-blind placebo-controlled challenges. The aim of this study was to determine: the frequency, type and sources of dietary advice being offered to patients, the prevalence of dietary modification, whether dietary changes were perceived to be of benefit and the type and sources of food/beverage reactions that people perceive they have experienced. METHOD: A self-administered 'food and asthma' questionnaire was developed and mailed to 156 consecutive Alfred Hospital Asthma and Allergy Clinic patients registered on a computer database. RESULTS: The completed questionnaire response rate was 86.5%. Dietary advice had been offered to 47% of respondents while 61% had tried to modify their diet. Dietary restriction was the most common dietary modification. Where dietary restriction had occurred 79% of respondents perceived that this had improved their asthma control. A doctor was the most common source of dietary advice. Seventy-three per cent reported that food induced asthma. CONCLUSION: We confirmed that patients with asthma perceived diet to be important in their asthma control and that dietary modification is common despite its lack of objective basis. The influence of diet and asthma requires more research, evaluation and clinical attention.

Adult↗
PubMed1996

Seasonal comparison of cytokine profiles in atopic asthmatics and atopic non-asthmatics.

Previous studies have suggested that peripheral blood T cell cytokine release may reflect the situation in the bronchial mucosa in atopic asthmatics. We have therefore examined spontaneous, rye grass pollen-stimulated, and PHA-stimulated secretion of IL-2, IL-4, IL-5, and IFN-gamma in cultures of peripheral blood mononuclear cells (PBMC) from atopic asthmatic, atopic non-asthmatic and normal controls in and out of the rye grass pollen season. Compared to normal controls, both atopic groups showed higher IL-2 and IL-5 production (p < 0.01 and p < 0.05) and higher percentages of CD4 cells expressing CD25 and HLA-DR (p < 0.05) in response to rye grass pollen, elevated IL-4 production in response to PHA (p < 0.01), and a non-significant trend towards lower IFN-gamma production. However, the capacity of PBMC from atopic asthmatics to produce IL-5 was greater than that for atopic non-asthmatics (p < 0.05). Furthermore, seasonal changes in symptom score, FEV1 % predicted, and PD20 methacholine correlated with seasonal elevated production of IL-5 by PBMC in the asthmatic group (r = 0.862, -0.679, and -0.620; p < 0.01, 0.02, and 0.05, respectively). Our results suggest that elevated production of IL-2 and IL-4 and higher percentages of activated CD4 T cells are associated with atopy per se, but elevated production of IL-5 also relates to the clinical expression of atopic asthma.

Adult↗
PubMed1995

Chronic airflow obstruction in long-term survivors of allogeneic bone marrow transplantation.

Prospective pulmonary function tests (PFTs) of 49 long-term survivors of identical sibling bone marrow transplants (BMT) were analysed. Eight (16%) developed a persistent pulmonary syndrome characterised by a late onset, cough and dyspnoea, hyperinflation or patchy infiltrates on plain radiography and episodic bacterial infections. The predominant PFT pattern was obstructive (reduced forced expiratory ratio, FER) with a variable restrictive component (reduced vital capacity, VC). When compared with the other 41 patients (controls), mean FER (53% absolute) and VC (73% predicted) were significantly lower at 12 months (P = 0.005). Graft-versus-host disease (GVHD) was the only identifiable risk factor (odds ration 7.1). Five of 7 patients compared with 4 of 31 controls tested at 3 months had an abnormal FER or maximum mid-expiratory flow rate (MMFR), but not VC, prior to the onset of symptoms (P = 0.015). Patients with mild to moderate disease (FER 50-70%) had stable pulmonary function while severe cases progressed despite immunosuppressive agents. Earlier recognition of this syndrome by a reduced FER or MMFR may allow the initiation of therapy at a potentially reversible stage.

Adult↗
PubMed1992

Chimeric CD7 monoclonal antibody therapy in rheumatoid arthritis.

Murine monoclonal antibody (Mab) therapy in patients with rheumatoid arthritis (RA) produces an antimouse immunoglobulin response by the recipient. We studied a chimeric (human/mouse) CD7 Mab, in a dose ranging tolerability study in 10 patients with RA. Modest improvements in disease activity occurred with frequent acute adverse effects of malaise, fever and nausea. After treatment, peripheral blood T lymphocyte numbers fell by 50% and CD7 expression fell by 97% for less than 7 days. Our study demonstrates chimeric Mab function in vivo and illustrates the influence of antibody isotype and patient characteristics on adverse effects.

Adult↗
PubMed1991

Urinary leukotriene E4 levels after allergen and exercise challenge in bronchial asthma.

Urinary leukotriene E4 (LTE4) concentrations were measured in six asthmatic subjects after treadmill exercise, and in five asthmatic subjects after allergen challenge. Exercise and allergen challenge produced a 42 +/- 18% (mean +/- SD) and 22 +/- 8% fall in FEV1, respectively. The baseline concentration of urinary LTE4 in subjects challenged with exercise was 64 (27 to 150) pg/mg creatinine (geometric mean and 95% confidence interval), and in those challenged with allergen it was 36 (23 to 59) pg/mg creatinine. Urinary LTE4 concentrations did not change significantly in the 24 h after exercise. In contrast, there was a mean 4-fold increase in urinary LTE4 during the 3 h after allergen challenge.

Adult↗
PubMedDate not supplied

Asthma management: how effective is it in the community?

BACKGROUND: The National Asthma Campaign (NAC) was launched in Australia in 1989 with the major objective of improving asthma management through the implementation of a six-step asthma management plan. AIM: The objective of the present study was to analyse the management of asthma in a cohort of adults with self-reported asthma 10 years after the commencement of the NAC. METHODS: The subjects were participants in the laboratory phase of a cross-sectional epidemiological study conducted in Melbourne in 1999-2000. Participants completed the detailed European Community Respiratory Health Survey, which included specific questions about their asthma management. Participants were included in this analysis if they had a positive response to the question 'Have you ever had asthma?'. This resulted in a total of 435 subjects. RESULTS: Of the subjects with self-reported asthma, over half of the participants reported that a doctor had ever measured their breathing (52.9%). However, only 10.1% of participants reported that they owned a peakflow meter (PFM) and only 13.3% reported that they had ever been given a written action plan. In comparison with data reported from 1993, doctor measurement of lung function has decreased significantly (P < 0.000 1), as has PFM ownership (P < 0.0001) and, importantly, possession of a written action plan (P = 0.0004). CONCLUSIONS: Asthma management among adults still falls well short of NAC guidelines. The decline in some key features over recent years suggests that new management and dissemination strategies are required.

Adult↗