Biomedical subjects

Dirkje Postma

Publications and source records attributed to Dirkje Postma.

13 recordsLinked to original sources

PubMed2006

Purification of decorin core protein from human lung tissue.

A chromatographic method to purify decorin core protein from human lung tissue is described. The method is simple and rapid, using a combination of two-anion exchange and one reversed phase chromatography steps and the enzymatic digestion with chondroitinase ABC. Approximately 170 microg decorin core protein were purified from 25 g of lung tissue with an enrichment factor of 1800-fold relative to the initial protein content. SDS-PAGE analysis of the final product revealed a single 42 kDa protein band, which was recognized by anti-decorin antibodies upon Western blotting and identified by mass spectrometry. Further digestion with PNGase F evidenced the presence of three N-linked oligosaccharides on the core protein. This method forms the basis for studying structural alterations of decorin related to the pathology of diseases where tissue destruction plays a role.

Amino Acid Sequence↗

PubMed2006

Does early indoor microbial exposure reduce the risk of asthma? The Prevention and Incidence of Asthma and Mite Allergy birth cohort study.

BACKGROUND: Exposure to microbial agents might inhibit the development of atopy and asthma. OBJECTIVE: We measured the association between microbial exposure assessed at 3 months and the development of atopic sensitization and doctor-diagnosed (DD) asthma and wheeze in the first 4 years in a birth cohort study of children with atopic mothers. METHODS: Endotoxin, fungal (1-->3)-beta-D-glucans, extracellular polysaccharides from the genera Penicillium and Aspergillus (EPS-Pen/Asp), and dust on living room floors were measured at 3 months of age. Serum IgE levels against common allergens were determined at 1 and 4 years, and questionnaire information about respiratory morbidity was collected yearly. RESULTS: Microbial levels in mattresses were low and not associated with serum IgE levels, DD asthma, and wheeze. Floor levels of biocontaminants and dust, on the other hand, were inversely associated with DD asthma, being most pronounced for endotoxin (odds ratio [OR], 0.40; 95% CI, 0.21-0.77) and EPS-Pen/Asp (OR, 0.42; 95% CI, 0.18-0.99). Mutual adjustment for other exposures did not significantly alter the results for endotoxin and only moderately affected the results for EPS-Pen/Asp. Persistent wheeze was also consistently less common in the high-exposure group, being significant only for EPS-Pen/Asp (OR, 0.37; 95% CI, 0.15-0.96). Transient wheeze and wheeze in the past 12 months were also reduced, but effects were smaller and not significant. Relationships with serum-specific IgE levels, which could only be assessed in 41% at age 4 years, were less pronounced and statistically significant only for EPS-Pen/Asp. CONCLUSIONS: Early exposure to common microbial contaminants, including fungal agents, might protect against asthma. CLINICAL IMPLICATIONS: Microbial exposure in early life might protect against asthma and might constitute a novel target for prevention.

Allergens↗

PubMed2006

Pulmonary biomarkers in chronic obstructive pulmonary disease.

There has been increasing interest in using pulmonary biomarkers to understand and monitor the inflammation in the respiratory tract of patients with chronic obstructive pulmonary disease (COPD). In this Pulmonary Perspective we discuss the merits of the various approaches by reviewing the current literature on pulmonary biomarkers in COPD and underscore the need for more systematic studies in the future. Bronchial biopsies and bronchoalveolar lavage provide valuable information about inflammatory cells and mediators, but are invasive, so that repeated measurements have to be very limited in assessing any interventions. Induced sputum has provided considerable information about the inflammatory process, including mediators and proteinases in COPD, but selectively samples proximal airways and may not closely reflect distal inflammatory processes. Exhaled gases and breath condensate are noninvasive procedures, so repeated measurements are possible, but for some assays the variability is relatively high. There is relatively little information about how any of these biomarkers relate to other clinical outcomes, such as progression of the disease, severity of disease, clinical subtypes, or response to therapy. More information is also needed about the variability in these measurements. In the future, pulmonary biomarkers may be useful in predicting disease progression, indicating disease instability, and in predicting response to current therapies and novel therapies, many of which are now in development.

Biomarkers↗

PubMed2005

Allergen exposure in infancy and the development of sensitization, wheeze, and asthma at 4 years.

BACKGROUND: The relationship between mite and pet allergen exposure in infancy and the subsequent development of sensitization and asthma is complex. OBJECTIVE: We prospectively investigated the effect of allergen exposure at 3 months of age on the development of sensitization, wheeze, and physician-diagnosed asthma in the first 4 years of life in a birth cohort of children with and without an atopic mother. METHODS: Children participated in the Prevention and Incidence of Asthma and Mite Allergy study. Allergen exposure at 3 months of age was determined from mattress dust samples. Specific IgE to inhalant allergens was measured at 4 years of age, and information about wheeze and physician-diagnosed asthma was collected with yearly questionnaires. RESULTS: Mite and cat allergen exposure in infancy were associated with an increased risk of specific sensitization to house dust mite and cat, respectively, at 4 years of age. There were borderline significant associations between cat allergen exposure and persistent wheeze in the total study population and between dog allergen exposure and persistent wheeze in children with a nonatopic mother. In children with an atopic mother, there was some indication of a positive association between mite allergen exposure and physician-diagnosed asthma. CONCLUSION: Early house dust mite and cat allergen exposure might lead to sensitization and, in case of cat allergen exposure, to persistent wheeze. Early mite and dog allergen exposure might lead to asthma and persistent wheeze, respectively, but only in subgroups defined by maternal atopy.

Adult↗

PubMed2005

High cessation rates of cigarette smoking in subjects with and without COPD.

BACKGROUND/OBJECTIVE: In general, smoking cessation programs have low success rates. We evaluated the effectiveness of a 1-year smoking cessation program. This program was part of a research project investigating the effects of smoking cessation. PARTICIPANTS: In this longitudinal study on the effects of 1 year of smoking cessation, 38 smokers with COPD or chronic bronchitis (mean age, 55 years; 20 men) and 25 healthy subjects (mean age, 50 years; 11 men) who smoked on average 22 cigarettes per day were recruited. METHODS AND RESULTS: An experienced nurse and a researcher conducted an intensive nonpharmacologic smoking cessation program based on 15 group meetings of 8 to 10 participants. A uniquely high number of 16 COPD or chronic bronchitis patients (42%) and 17 healthy subjects (68%) did not smoke 1 year after stopping smoking. CONCLUSION: We suggest that frequent and intensive motivational support in a research setting accounts for the high cessation rates.

Bronchitis↗

PubMed2005