Biomedical subjects

P K Jeffery

Publications and source records attributed to P K Jeffery.

At least 19 recordsLinked to original sources

PubMed2006

Intravenously administered oligonucleotides can be delivered to conducting airway epithelium via the bronchial circulation.

Topical gene transfer to the airways of cystic fibrosis (CF) patients has been inefficient, partly due to extracellular barriers such as sputum. In an attempt to circumvent these, we assessed whether airway epithelial cells can be transfected by intravenous (i.v.) administration of liposome-complexed or "naked" oligonucleotides (ODNs). The conducting airways are the likely target for CF therapy and are supplied by the bronchial circulation. Consequently, we assessed ODN transfer in the mouse trachea and main bronchi as these are supplied by the bronchial circulation. Liposome-protamine-DNA (LPD) complexes were detected in the bronchial circulation but did not transfect conducting airway epithelial cells, even in the presence of microvascular leakage. In contrast, 'naked' ODNs were delivered to 17% (inter-quartile range (IQR) 10-34%) and 35% (IQR 24-59%) of epithelial cells when injected at 500 microg/animal, without and with microvascular leakage, respectively. Two types of nuclear signal were observed; punctate in cells throughout the airways (3%, IQR 2-6%, and 6%, IQR 4-7%, of cells when delivered without and with microvascular leakage, respectively) and diffuse in a small number of epithelial cells in the proximal trachea. ODNs may be relevant to CF in a variety of ways and these data suggest one way towards implementing their use.

Animals↗

PubMed2006

Ultrastructure of the reticular basement membrane in asthmatic adults, children and infants.

Reticular basement membrane (RBM) thickening in asthma is considered to be the result of subepithelial fibrosis. Thus, the RBM in asthma should contain an excess of fibrils identified as interstitial collagen and the ratio of fibril to matrix should be increased above normal levels. Electron micrographs of the RBM were compared with those of interstitial collagen deeper in the bronchial wall using endobronchial biopsy specimens from adult asthmatics (aged 18-41 yrs (n = 10)), children with difficult asthma (aged 6-16 yrs (n = 10)), wheezy infants with reversible airflow limitation (aged 0.3-2 yrs (n = 10)) and age-matched nonasthmatic controls: 10 adults, nine children and nine symptomatic infants with normal lung function. Fibrils in the RBM were significantly thinner (median (range) width 39 (30-52) nm versus 59 (48-73) nm), and fewer fibrils were banded than in the interstitial collagen (ratio of banded to non-banded fibrils 0.08 (0-0.17) versus 0.22 (0-1.3)). The ratio of fibrils to matrix in the thickened RBM of asthmatics did not differ from that of their respective controls (1.34 (0.63-2.49) versus 1.18 (0.31-2.6)). The ratio of fibril to matrix in the thickened reticular basement membrane of asthmatics is normal, and, contrary to what is expected in fibrosis, the fibrils do not resemble those of interstitial collagen.

Adolescent↗

PubMed2006

Can HRCT be used as a marker of airway remodelling in children with difficult asthma?

BACKGROUND: Whole airway wall thickening on high resolution computed tomography (HRCT) is reported to parallel thickening of the bronchial epithelial reticular basement membrane (RBM) in adult asthmatics. A similar relationship in children with difficult asthma (DA), in whom RBM thickening is a known feature, may allow the use of HRCT as a non-invasive marker of airway remodelling. We evaluated this relationship in children with DA. METHODS: 27 children (median age 10.5 [range 4.1-16.7] years) with DA, underwent endobronchial biopsy from the right lower lobe and HRCT less than 4 months apart. HRCTs were assessed for bronchial wall thickening (BWT) of the right lower lobe using semi-quantitative and quantitative scoring techniques. The semi-quantitative score (grade 0-4) was an overall assessment of BWT of all clearly identifiable airways in HRCT scans. The quantitative score (BWT %; defined as [airway outer diameter - airway lumen diameter]/airway outer diameter x100) was the average score of all airways visible and calculated using electronic endpoint callipers. RBM thickness in endobronchial biopsies was measured using image analysis. 23/27 subjects performed spirometry and the relationships between RBM thickness and BWT with airflow obstruction evaluated. RESULTS: Median RBM thickness in endobronchial biopsies was 6.7(range 4.6-10.0) microm. Median qualitative score for BWT of the right lower lobe was 1(range 0-1.5) and quantitative score was 54.3 (range 48.2-65.6)%. There was no relationship between RBM thickness and BWT in the right lower lobe using either scoring technique. No relationship was found between FEV1 and BWT or RBM thickness. CONCLUSION: Although a relationship between RBM thickness and BWT on HRCT has been found in adults with asthma, this relationship does not appear to hold true in children with DA.

Adolescent↗

PubMed2006

Variability of bronchial inflammation in chronic obstructive pulmonary disease: implications for study design.

There is variability in the distribution of inflammatory cells in bronchial tissue in chronic obstructive pulmonary disease (COPD). Better strategies for biopsy sampling of the airway mucosa may improve the capacity to show a difference between study populations where variability in distribution exists. The current authors have examined sources of biological variability in the quantification of inflammatory cells in endobronchial biopsies using immunostained samples taken from 51 subjects with COPD, with a mean forced expiratory volume in one second of 1.71 L, 55% predicted. The distribution of variance contributed by different sources was similar for different inflammatory cell types. For CD8+ cells, a key inflammatory cell in COPD, the largest contribution to intra-subject variability (39%) was time (i.e. 10 weeks between biopsies of placebo-treated subjects), followed by airway generation (23%), biopsy (2.5%), zone (within section; 1.4%) and section (0.4%). Power calculations demonstrated that examining one section from one biopsy, from each of two airway generations, would require a sample size of 32 subjects per group to show a difference of one doubling or halving in CD8+ cells, compared with 47 subjects per group if only one airway generation was sampled. Therefore, biopsies from more than one airway generation should be examined in order to maximise statistical power to detect a difference between study groups.

Adult↗

PubMed2005

Keratinocyte growth factor therapy in murine oleic acid-induced acute lung injury.

Alveolar type II (ATII) cell proliferation and differentiation are important mechanisms in repair following injury to the alveolar epithelium. KGF is a potent ATII cell mitogen, which has been demonstrated to be protective in a number of animal models of lung injury. We have assessed the effect of recombinant human KGF (rhKGF) and liposome-mediated KGF gene delivery in vivo and evaluated the potential of KGF as a therapy for acute lung injury in mice. rhKGF was administered intratracheally in male BALB/c mice to assess dose response and time course of proliferation. SP-B immunohistochemistry demonstrated significant increases in ATII cell numbers at all rhKGF doses compared with control animals and peaked 2 days following administration of 10 mg/kg rhKGF. Protein therapy in general is very expensive, and gene therapy has been suggested as a cheaper alternative for many protein replacement therapies. We evaluated the effect of topical and systemic liposome-mediated KGF-gene delivery on ATII cell proliferation. SP-B immunohistochemistry showed only modest increases in ATII cell numbers following gene delivery, and these approaches were therefore not believed to be capable of reaching therapeutic levels. The effect of rhKGF was evaluated in a murine model of OA-induced lung injury. This model was found to be associated with significant alveolar damage leading to severe impairment of gas exchange and lung compliance. Pretreatment with rhKGF 2 days before intravenous OA challenge resulted in significant improvements in PO2, PCO2, and lung compliance. This study suggests the feasibility of KGF as a therapy for acute lung injury.

Acute Disease↗

PubMed2004

A defective nontransmissible recombinant Sendai virus mediates efficient gene transfer to airway epithelium in vivo.

Recombinant Sendai virus (SeV)-mediated gene transfer to differentiated airway epithelial cells has shown to be very efficient, because of its ability to overcome the intra- and extracellular barriers known to limit gene delivery. However, this virus is transmission competent and therefore unlikely to be suitable for use in clinical trials. A nontransmissible, replication-competent recombinant SeV has recently been developed by deleting the envelope Fusion (F) protein gene (SeV/DeltaF). Here we show that SeV/DeltaF is able to mediate beta-galactosidase reporter gene transfer to the respiratory tract of mice in vivo, as well as to human nasal epithelial cells in vitro. Further, in an ex vivo model of differentiated airway epithelium, SeV/DeltaF gene transfer was not importantly inhibited by native mucus. When compared to the transmission-competent SeV in vivo, no difference in gene expression was observed at the time of peak expression. The development of an F-defective nontransmissible SeV, which can still efficiently mediate gene transfer to the airway epithelium, represents the first important step towards the use of a cytoplasmic RNA viral vector in clinical trials of gene therapy.

Adult↗

PubMed2004

Airway inflammation in children with difficult asthma: relationships with airflow limitation and persistent symptoms.

BACKGROUND: The effective management and development of new treatments for children with difficult asthma requires investigation of the underlying airway pathology and its relationships with persistent symptoms and airflow limitation. METHODS: The density of immunologically distinct inflammatory cells and cells expressing interleukin (IL)-4, IL-5, and RANTES was determined in paraffin-embedded endobronchial biopsy specimens from 27 children with difficult asthma (6-16 years) following treatment with systemic corticosteroids. Eleven non-asthmatic children (7-16 years) acted as controls. Reticular basement membrane (RBM) thickness was also recorded and forced expiratory volume in 1 second (FEV(1)) and exhaled nitric oxide (FE(NO)) measured, the latter in asthmatic children only. RESULTS: RBM thickness was greater in the asthmatic than the control group (median (range) 7.4 (3.1-11.1) v 5.1 (3.5-7.5) microm, p = 0.02). No other significant tissue difference was seen, nor was there a difference between asthmatic subjects with daily symptoms after systemic corticosteroids and those who became asymptomatic. CD4+ T lymphocyte density was higher in asthmatic subjects with persistent airflow limitation (post-bronchodilator FEV(1)<80% predicted) than in those without (9.1 (5.5-13.6) v 3.5 (0.6-34.9)%, p = 0.027). Analysing all asthmatic subjects together, there were negative correlations between CD4+ T lymphocytes and both pre-bronchodilator FEV(1) (r = -0.57 (95% CI -0.79 to -0.23), p = 0.002) and post-bronchodilator FEV(1) (r = -0.61 (95% CI -0.81 to -0.29), p<0.001). There were no significant correlations between FE(NO) and inflammatory cells of any type. CONCLUSION: In children with difficult asthma treated with systemic corticosteroids, persistent airflow limitation is associated with a greater density of CD4+ T lymphocytes in endobronchial biopsy specimens.

Adolescent↗

PubMed2004

Safety of research bronchoscopy, biopsy and bronchoalveolar lavage in asthma.

Bronchoscopy with endobronchial biopsy (EBB) and/or bronchoalveolar lavage (BAL) has become an important research tool in asthma. A recent report has suggested audit and reporting of the safety of these procedures. A total of 159 asthmatic patients (84 males, 75 females), aged 18-52 (median 27) yrs, forced expiratory volume in one second 53-120 (median 88) % predicted, underwent 273 bronchoscopies in six clinical research studies. On 228 occasions, EBB and BAL were performed and, on 45 occasions, EBB was performed alone. On 48 occasions, bronchoscopy was performed 24 h post-allergen challenge. Adverse events occurred on 34 out of 273 occasions, none of which were following allergen challenge. Post-EBB and BAL, four patients developed pleuritic chest pain, shortness of breath and fever. A further two patients experienced pleuritic chest pain alone post-EBB/BAL. Bronchospasm or worsening of asthma symptoms occurred on 14 occasions, 13 post-EBB/BAL and on one occasion post-EBB alone. Fever/flu-like symptoms were reported on nine occasions following EBB and BAL. One subject had haemoptysis post-EBB/BAL, but required no intervention. In conclusion, bronchoscopy, endobronchial biopsy and bronchoalveolar lavage can be performed safely in asthmatic patients. Most of the complications were seen where bronchoalveolar lavage and endobronchial biopsy were both performed, suggesting that bronchoalveolar lavage accounts for most of the adverse events.

Adult↗

PubMed2003

Variation of CD8+ T-lymphocytes around the bronchial internal perimeter in chronic bronchitis.

The variation of CD8+ cells has been determined around the internal perimeter of intrapulmonary bronchi in smokers with chronic bronchitis (CB), and the amount of tissue required to confidently estimate the true mean has been calculated. Lung specimens were obtained from 10 smokers with CB. Paraffin sections of intrapulmonary bronchi were immunostained and CD8+ cells counted in the epithelium and subepithelium in up to 10 sequential 1-mm segments around the internal perimeter of each airway. The percentage of counts falling between +/-20% of the final mean was 43.0% for epithelium and 40.9% for subepithelium. In 90% of subjects, the cumulative mean was stable after examination of subepithelial tissue associated with 5 mm of reticular basement membrane. There is considerable variation in the counts of CD8+ cells between adjacent 1-mm airway mucosal segments in chronic bronchitis. In order to achieve a representative count and to maximise statistical power to detect differences between study populations, subepithelial tissue including a minimum of 5 mm of reticular basement membrane length should be examined.

Aged↗

PubMed2002

Effects of fluticasone propionate on inflammatory cells in COPD: an ultrastructural examination of endobronchial biopsy tissue.

BACKGROUND: Inhaled corticosteroids (ICS) markedly reduce bronchial mucosal inflammation in asthma but whether they have an anti-inflammatory effect in airway tissue in chronic obstructive pulmonary disease (COPD) is unknown. METHODS: A study of endobronchial biopsy samples was conducted as part of a double blind, placebo controlled, randomised trial of parallel design. Patients had mild to moderately severe COPD (FEV(1) 25-80% of predicted) and were given 3 months treatment with ICS, fluticasone propionate (FP; 500 micro g twice daily, n=14) or placebo (n=10). Biopsy tissue taken at baseline and after treatment was examined by transmission electron microscopy to count the numbers of all ultrastructurally distinct inflammatory cells. RESULTS: Compared with their baseline values, FP resulted in a significant decrease (on average 65%) in the numbers of mucosal mast cells (median 7.8 (range 1-33) v 2.8 (1-14), p<0.05). The reductive effect of FP held true when the post-treatment values of the placebo and FP groups were compared: 8.8 (1-24) v 2.8 (1-14) (p<0.05). Unexpectedly, there were significantly more neutrophils in the FP than in the placebo group: 4.0 (0-23) v 1.7 (0-8), respectively (p<0.05). There were no alterations to other cell types including mononuclear cells. Symptoms markedly improved in the patients treated with FP for 3 months. CONCLUSION: Fluticasone propionate given for 3 months to patients with COPD has selective effects on the inflammatory cells in the bronchial mucosa: the reduction in mast cell numbers may account for the improvement in symptoms over this time.

Aged↗

PubMed2002

Effects of salmeterol on mucosal inflammation in asthma: a placebo-controlled study.

Although the anti-inflammatory effects of inhaled corticosteroids in the treatment of asthma are established, the effects of long-acting beta2-adrenergic receptor agonists on inflammation are the subject of debate. The aim of the present study was to determine the effect of salmeterol on the numbers of inflammatory cells in biopsy samples of distinct immunophenotype and those expressing the genes for interleukin-4 and -5, regulatory cytokines particularly relevant to asthma. Twenty patients (aged 18-55 yrs) with mild stable asthma were randomised in a three-way crossover study to 6 weeks of treatment with: 1) salmeterol (50 microg b.d.; SM50); 2) fluticasone propionate (250 microg b.d.; FP250), or 3) placebo. Compared with placebo, SM50 significantly reduced the numbers of neutrophils in bronchial biopsy samples and the concentrations of myeloperoxidase and soluble E-selectin in serum, each of which reflect neutrophil involvement. Compared with FP250, SM50 reduced neutrophil number and human neutrophil lipocalin level in bronchial lavage fluid and intercellular adhesion molecule-1 level in bronchoalveolar lavage fluid. Compared with placebo, FP250 significantly reduced the numbers of (CD3+) T-lymphocytes, (CD4+) T-helper cells, (CD45RO+) activated T-helper cells and eosinophils in the biopsy samples; it also reduced the percentage of eosinophils and soluble intercellular adhesion molecule-1 in serum. The percentage of symptom-free days and nights and airways hyperresponsiveness improved significantly after SM50 compared to both placebo and FP250. In conclusion, a novel antineutrophilic effect of the inhaled long-acting beta2-adrenergic receptor agonist, salmeterol, in mild asthma is reported.

Adrenergic beta-Agonists↗

PubMed2001

Interleukin-4 and interleukin-5 gene expression and inflammation in the mucus-secreting glands and subepithelial tissue of smokers with chronic bronchitis. Lack of relationship with CD8(+) cells.

We wished to determine if the inflammatory cells surrounding the airway mucus-secreting glands in chronic bronchitis (CB) were associated with interleukin (IL)-4 and IL-5 mRNA expression and whether the CD8 T cell population expressed these cytokines. Digoxigenin-labeled IL-4 and IL-5 antisense RNA probes were used to detect gene expression in 11 asymptomic smokers (AS), 11 smokers with CB alone with normal lung function, and 10 smokers with chronic bronchitis and coexisting chronic obstructive pulmonary disease (CB+COPD; FEV(1)% of predicted of 43-77% and FEV(1)/ FVC of 51-68%). There were approximately three times as many IL-4 than IL-5 mRNA(+) cells. The highest number of IL-4 mRNA(+) cells were in the submucosal glands of the CB group with normal lung function (216/mm(2)), significantly higher than the values in either the AS (63/mm(2)) or the CB+COPD (87/mm(2)) groups, respectively (p < 0.01). There were similar group differences when the total numbers of inflammatory cells were compared. Accordingly, there was a positive correlation between the number of IL-4 mRNA(+) cells and the total number of inflammatory cells in both the subepithelium and glandular compartments (r = 0.60; p = 0.01 and r = 0.70; p = 0.02, respectively). There were no significant associations between the numbers of CD8(+) and IL-4 or IL-5 mRNA(+) cells. Of 1328 IL-4(+) and 1404 CD8(+) cells counted none was double labeled. Of 727 IL-5(+) and 1569 CD8(+) cells, none was double labeled. In contrast, as a positive control, 34% of tumor necrosis factor (TNF)-alpha(+) cells were also CD8(+) and 15% of CD8(+) cells were TNF-alpha positive. Thus, cells other than the CD8(+) phenotype produce IL-4 and IL-5 in CB. We conclude that there is increased inflammation and IL-4 gene expression in the mucus-secreting glands and the airway mucosa of smokers with bronchitis: both are lower in those with CB and coexisting COPD suggesting that airway inflammation in CB is reduced when airway obstruction develops.

Aged↗

PubMed2001

Remodeling in asthma and chronic obstructive lung disease.

Asthma and chronic obstructive lung disease (COPD) are both inflammatory conditions of the lung associated with structural "remodeling" inappropriate to the maintenance of normal lung function. The clinically observed distinctions between asthma and COPD are reflected by differences in the remodeling process, the patterns of inflammatory cells and cytokines, and also the predominant anatomic site at which these alterations occur. In asthma the epithelium appears to be more fragile than that of COPD, the epithelial reticular basement membrane (RBM) is significantly thicker, there is marked enlargement of the mass of bronchial smooth muscle, and emphysema does not occur in the asthmatic nonsmoker. In COPD, there is epithelial mucous metaplasia, airway wall fibrosis, and inflammation associated with loss of surrounding alveolar attachments to the outer wall of small airways: bronchiolar smooth muscle is increased also. Emphysema is a feature of severe COPD: in spite of the destructive process, alveolar wall thickening and focal fibrosis may be detected. The hypertrophy of submucosal mucus-secreting glands is similar in extent in asthma and COPD. The number of bronchial vessels and the area of the wall occupied by them increase in severe corticosteroid-dependent asthma: it is likely that these increases also occur in severe COPD as they do in bronchiectasis. Pulmonary vasculature is remodeled in COPD. In asthma several of these structural alterations begin early in the disease process, even in the child. In COPD the changes begin later in life and the associated inflammatory response differs from that in asthma. The following synopsis defines and compares the key remodeling processes and proposes several hypotheses.

Adolescent↗

PubMed2001

Oxidant-mediated lung epithelial cell tolerance: the role of intracellular glutathione and nuclear factor-kappaB.

The airway epithelium is injured by oxidants inhaled as atmospheric pollutants or produced during inflammatory responses. We studied the effect of modulating the antioxidant intracellular glutathione, both using thiol compounds and by the adaptive effect of hyperoxia, on oxidant-induced injury and activation of the nuclear factor-kappaB (NF-kappaB) in two cell lines: the human bronchial (16HBE) and type II alveolar epithelial cells (A549). The thiol antioxidants glutathione (GSH) and glutathione monoethyl ester (GSH-MEE) [2 mM] increased GSH levels (nmol/mg protein) in A549 cells (GSH 383 +/- 26 and GSH-MEE 336 +/- 23 vs control 171 +/- 13, P < 0.001) and in 16HBE cells (GSH 405 +/- 33, GSH-MEE 362 +/- 37 vs control 198 +/- 12, P < 0.001, N = 3). Treatment of hyperoxia (95% oxygen) also increased GSH levels between 4 and 24 hr exposure compared with control (P < 0.01). Hydrogen peroxide (H(2)O(2)) (0.01 mM) induced NF-kappaB activation, whereas hyperoxia exposure did not affect NF-kappaB activation in either cell line. Pretreatment with dl-buthionine (SR)-sulfoximine, which decreased intracellular glutathione, increased NF-kappaB binding induced by H(2)O(2) and increased lactate dehydrogenase (LDH) release (P < 0.001). Pretreatment with the thiol compounds and hyperoxia totally inhibited H(2)O(2)-induced NF-kappaB binding and cell injury as measured by LDH release. These data indicate the importance of intracellular glutathione and inhibition of NF-kappaB in both protection/tolerance against oxidant-induced epithelial cell injury, and NF-kappaB activation in response to oxidative stress which may be important in lung inflammation. Thus, increasing intracellular glutathione may be of therapeutic relevance if able to modulate NF-kappaB activation and hence attenuate inflammation.

Adaptation, Biological↗

PubMed2001

Exacerbations of Bronchitis: bronchial eosinophilia and gene expression for interleukin-4, interleukin-5, and eosinophil chemoattractants.

Eosinophilia has been reported during exacerbations of bronchitis, but the mechanisms of tissue recruitment of eosinophils are unclear. We quantified eosinophils and the concurrent expression of cytokines and chemokines probably responsible for the tissue eosinophilia in bronchial biopsies obtained from three groups of nonatopic subjects: (1) healthy nonsmokers (n = 7; FEV1 % predicted = 108 +/- 4 [mean +/- SEM]); (2) nonasthmatic smokers with chronic bronchitis (CB) in a stable phase of their disease (n = 11; FEV1 % predicted: 75 +/- 5); and (3) nonasthmatic subjects with CB who sought medical advice for an exacerbation of their condition (n = 9; FEV(1) % predicted: 61 +/- 8). We applied anti-EG2 antibody and immunostaining to detect and count eosinophils. We performed in situ hybridization to visualize and enumerate cells expressing the genes for interleukin (IL)-4 and IL-5 and the eosinophil chemokines eotaxin, monocyte chemoattractant protein (MCP)-4, or regulated on activation, normal T-cell expressed and secreted (RANTES). We confirmed an increase in EG2-positive eosinophils in patients with CB in exacerbation. We found messenger RNA (mRNA) positivity for IL-4 and IL-5 in CB, but the between-group differences were not statistically significant. However, the numbers of lymphomononuclear cells expressing eotaxin mRNA were significantly greater in the smokers with CB than in the healthy nonsmokers without CB (p < 0.01). Following an exacerbation, RANTES expression was upregulated and this chemokine was strongly expressed in both the surface epithelium and in subepithelial lymphomononuclear cells: only RANTES showed a significant positive correlation with the increasing number of EG2-positive cells (r = 0.51; p < 0.03). In conclusion, an allergic profile of inflammation can also occur in CB: the marked upregulation of RANTES in the epithelium and subepithelium most likely accounts for the increased eosinophilia associated with an exacerbation of bronchitis.

Adult↗

PubMed2001

Degranulation patterns of eosinophil granulocytes as determinants of eosinophil driven disease.

BACKGROUND: Degranulation of eosinophils in target tissues is considered a key pathogenic event in major chronic eosinophilic diseases. However, because of a lack of appropriate methods, little is known about degranulation of eosinophils in common eosinophilic diseases. METHODS: Using transmission electron microscopic (TEM) analysis, a novel approach has been devised and validated to quantify eosinophil degranulation in human tissues (assessed in individual cells as percentage granules with structural signs of protein release). Biopsy specimens from patients with inflammatory bowel disease, allergic rhinitis, asthma, and nasal polyposis were evaluated. RESULTS: All conditions displayed a similar degree of local tissue eosinophilia, with no differences being observed in eosinophil numbers in the airway mucosa of patients with airway diseases and the colonic mucosa of those with inflammatory bowel disease (IBD). In contrast, marked differences in the mean (SE) extent of eosinophil degranulation were observed between the patient groups; IBD 9.3 (1.4)% altered granules, artificial and natural allergen challenge induced allergic rhinitis 67.8 (6.8)% and 86.6 (3.0)%, respectively, asthma 18.1 (2)%, and nasal polyposis 46.6 (7.6)%. CONCLUSIONS: This study provides the first quantitative data which show that different eosinophilic conditions, despite having similar numbers of tissue eosinophils, may exhibit markedly different degranulation patterns. The present assessment of piecemeal degranulation would thus make it possible to delineate the conditions under which eosinophils are likely to contribute to disease processes. This novel type of analysis may also guide and validate anti-eosinophilic treatment options.

Apoptosis↗

PubMed2001

Localisation of transforming growth factor beta1 and beta3 mRNA transcripts in normal and fibrotic human lung.

BACKGROUND: Transforming growth factor beta1 is implicated in the pathogenesis of lung fibrosis. It promotes extracellular matrix accumulation by increasing procollagen synthesis and reducing degradation. TGFbeta1 gene and protein expression increase in experimental lung fibrosis, and TGFbeta1 antibodies attenuate fibrosis in mice. The role of other TGFbeta isoforms is unclear. This study aimed to localise TGFbeta1 and TGFbeta3 gene expression in fibrotic human lung and compare it with that in normal human lung. METHODS: Lung tissue from patients with cryptogenic fibrosing alveolitis and fibrosis associated with systemic sclerosis was examined by in situ hybridisation. Macroscopically normal lung from carcinoma resections was used as control tissue. Digoxigenin labelled riboprobes were synthesised from TGFbeta isoform specific cDNA templates. RESULTS: The digoxigenin labelled riboprobes were sensitive and permitted precise cellular localisation of mRNA transcripts. TGFbeta1 and TGFbeta3 mRNA transcripts were widespread in normal lung and localised to alveolar macrophages and bronchiolar epithelium. TGFbeta1 but not TGFbeta3 mRNA was detected in mesenchymal and endothelial cells. In fibrotic lung tissue mRNA transcripts for both isoforms were also detected in metaplastic type II cells. TGFbeta1 gene expression was enhanced in some patients. TGFbeta3 was expressed in fibrotic lung but was not consistently altered compared with controls. CONCLUSION: TGFbeta1 mRNA transcripts were localised in normal and fibrotic human lung and TGFbeta3 gene expression in human lung fibrosis was shown for the first time. The results suggest that TGFbeta1 may play the predominant role in pathogenesis. It is suggested that TGFbeta1 should be the primary target of anticytokine treatments for pulmonary fibrosis.

Adult↗

PubMed2001

Lymphocytes, chronic bronchitis and chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a cytotoxic T lymphocyte (CD8)- and macrophage (CD68)-predominant chronic inflammatory disorder of the conducting airways and alveoli. This is often associated with a neutrophilia, inflammation of small airways and destruction of tissue beyond the terminal bronchiolus, i.e. emphysema. In contrast, asthma is a helper T cell (CD4; type 2)-predominant chronic inflammatory disorder of the conducting airways in which there is T lymphocyte-derived gene expression for interleukin (IL)-4 and IL-5 but not interferon gamma. There is fragility of airway surface epithelium, thickening of the reticular basement membrane, bronchial vessel congestion and (when severe) an increase in the mass of bronchial smooth muscle. This is usually (but not always) associated with tissue and peripheral blood eosinophilia rather than a neutrophilia and there is exudative plugging of the airways. These differences of inflammatory profile, remodelling and lung function are seen when smokers with COPD are compared with non-smoking mild asthmatics. However there may be important similarities and overlap, particularly in more severe asthma when neutrophils predominate and in the older and or smoking asthmatic when reversibility of airflow is less obvious. We have recently demonstrated gene expression for IL-4 and IL-5 in and around the mucus-secreting glands of airways resected from smokers without a history of asthma. Also exacerbations of bronchitis may be associated with a tissue eosinophilia. On examination of bronchial biopsies from these patients we show surprisingly strong gene expression for IL-4, IL-5 and even human eotaxin and RANTES (regulated on activation normal T cell expressed and secreted). Whilst CD4 T lymphocytes of the Th2 phenotype might be expressing these cytokines in bronchitis, CD8 T lymphocytes are also capable of secreting IL-4 and IL-5. Viruses may modulate these changes in distinct lymphocyte functional phenotypes. The relevance and importance of CD4/CD8 T lymphocyte ratio to the development of COPD is discussed.

Animals↗