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Schmekel, Birgitta
Alternative names
Publications (10 of 24) Show all publications
Schmekel, B., Winquist, F. & Vikström, A. (2014). Analysis of breath samples for lung cancer survival. Analytica Chimica Acta, 840, 82-86
Open this publication in new window or tab >>Analysis of breath samples for lung cancer survival
2014 (English)In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 840, p. 82-86Article in journal (Refereed) Published
Abstract [en]

Analyses of exhaled air by means of electronic noses offer a large diagnostic potential. Such analyses are non-invasive; samples can also be easily obtained from severely ill patients and repeated within short intervals. Lung cancer is the most deadly malignant tumor worldwide, and monitoring of lung cancer progression is of great importance and may help to decide best therapy. In this report, twenty-two patients with diagnosed lung cancer and ten healthy volunteers were studied using breath samples collected several times at certain intervals and analysed by an electronic nose. The samples were divided into three sub-groups; group d for survivor less than one year, group s for survivor more than a year and group h for the healthy volunteers. Prediction models based on partial least square and artificial neural nets could not classify the collected groups d, s and h, but separated well group d from group h. Using artificial neural net, group d could be separated from group s. Excellent predictions and stable models of survival day for group d were obtained, both based on partial least square and artificial neural nets, with correlation coefficients 0.981 and 0.985, respectively. Finally, the importance of consecutive measurements was shown.

Place, publisher, year, edition, pages
Elsevier Masson, 2014
Keywords
Breath analysis; Electronic nose; Lung cancer; Survival prediction
National Category
Clinical Medicine Biological Sciences
Identifiers
urn:nbn:se:liu:diva-109871 (URN)10.1016/j.aca.2014.05.034 (DOI)000339992500011 ()25086897 (PubMedID)
Note

Funding Agencies|County Council of Ostergotland

Available from: 2014-08-28 Created: 2014-08-28 Last updated: 2017-12-05
Norberg, P., Persson, H. L., Schmekel, B., Alm Carlsson, G., Wahlin, K., Sandborg, M. & Gustafsson, A. (2014). Does quantitative lung SPECT detect lung abnormalities earlier than lung function tests?: Results of a pilot study. EJNMMI Research, 4(39), 1-12
Open this publication in new window or tab >>Does quantitative lung SPECT detect lung abnormalities earlier than lung function tests?: Results of a pilot study
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2014 (English)In: EJNMMI Research, ISSN 2191-219X, E-ISSN 2191-219X, Vol. 4, no 39, p. 1-12Article in journal (Refereed) Published
Abstract [en]

Background: Heterogeneous ventilation in lungs of allergic individuals, cigarette smokers, asthmatics and chronic obstructive pulmonary disease (COPD) patients has been demonstrated using imaging modalities such as PET, MR and SPECT. These individuals suffer from narrow and/or closed airways to various extents. By calculating regional heterogeneity in lung ventilation SPECT images as the coefficient of variation (CV) in small elements of the lung, heterogeneity maps and CV-frequency curves can be generated and used to quantitatively measure heterogeneity. This work explores the potential to use such measurements to detect mild ventilation heterogeneities in lung healthy subjects.

Method: Fourteen healthy subjects without documented lung disease or respiratory symptoms, and two patients with documented airway disease, inhaled on average approximately 90 MBq 99mTc-Technegas immediately prior to the 20 min SPECT acquisition. Variation in activity uptake between subjects was compensated for in resulting CV values. The area under the compensated CV frequency curve (AUC), for CV values greater than a threshold value CVT, AUC(CV> CVT), was used as the measure of ventilation heterogeneity.

Results: Patients with lung function abnormalities, according to lung function tests, generated higher AUC(CV>20%) values compared to healthy subjects (p=0.006). Strong linear correlations with the AUC(CV>20%) values were found for age (p=0.006) and height (p=0.001). These demonstrated that ventilation heterogeneities increased with age and that they depend on lung size. Strong linear correlations were found for the lung function value related to indices of airway closure/air trapping, RV/TLC (p=0.009), and DLCOc (p=0.009), a value partly related to supposed ventilation/perfusion mismatch. These findings support the association between conventional lung function tests and the AUC(CV>20%) value.

Conclusions: Among the healthy subjects there is a group with increased AUC(CV>20%) values, but with normal lung function tests, which implies that it might be possible to differentiate ventilation heterogeneities earlier in a disease process than by lung function tests.

Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2014
Keywords
Quantitative lung SPECT, ventilation heterogeneities, lung function tests
National Category
Clinical Medicine Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-106666 (URN)10.1186/s13550-014-0039-1 (DOI)000358049300001 ()26055938 (PubMedID)2-s2.0-84905881037 (Scopus ID)
Note

On the date of the defence date of the Ph.D. Thesis the status of this article was Manuscript.

Available from: 2014-05-19 Created: 2014-05-19 Last updated: 2017-12-05Bibliographically approved
Blomstrand, P., Ekedahl, S. & Schmekel, B. (2013). Bronchial Responsiveness to Dry Air Hyperventilation in Smokers May Predict Decline in Airway Status Using Indirect Methods. Lung, 191(2), 183-190
Open this publication in new window or tab >>Bronchial Responsiveness to Dry Air Hyperventilation in Smokers May Predict Decline in Airway Status Using Indirect Methods
2013 (English)In: Lung, ISSN 0341-2040, E-ISSN 1432-1750, Vol. 191, no 2, p. 183-190Article in journal (Refereed) Published
Abstract [en]

Disabling respiratory symptoms and rapid decline of lung function may occur in susceptible tobacco smokers. Bronchial hyperresponsiveness (BHR) elicited by direct challenge methods predicts worse lung function outcomes. The aim of this study was to evaluate whether BHR to isocapnic hyperventilation of dry air (IHDA) was associated with rapid deterioration in airway status and respiratory symptoms. less thanbrgreater than less thanbrgreater thanOne hundred twenty-eight smokers and 26 age- and sex-matched healthy individuals with no history of smoking were investigated. All subjects completed a questionnaire. Spirometry and impulse oscillometry (IOS) measurements were recorded before and after 4 min of IHDA. The tests were repeated after 3 years in 102 smokers and 11 controls. less thanbrgreater than less thanbrgreater thanEighty-five smokers (66 %) responded to the challenge with a a parts per thousand yen2.4-Hz increase in resonant frequency (F (res)), the cutoff limit defining BHR, as recorded by IOS. They had higher F (res) at baseline compared to nonresponding smokers [12.8 +/- A 3.2 vs. 11.5 +/- A 3.4 Hz (p andlt; 0.05)] and lower FEV1 [83 +/- A 13 vs. 89 +/- A 13 % predicted (p andlt; 0.05)]. Multivariable logistic regression analysis indicated that wheezing (odds ratio = 3.7, p andlt; 0.01) and coughing (odds ratio = 8.1, p andlt; 0.05) were significantly associated with hyperresponsiveness. An increase in F (res) was recorded after 3 years in responding smokers but not in nonresponders or controls. The difference remained when subjects with COPD were excluded. less thanbrgreater than less thanbrgreater thanThe proportion of hyperresponsive smokers was unexpectedly high and there was a close association between wheezing and coughing and BHR. Only BHR could discriminate smokers with rapid deterioration of airway status from others.

Place, publisher, year, edition, pages
Springer Verlag (Germany), 2013
Keywords
Bronchial hyperresponsiveness, Impulse oscillometry, Isocapnic hyperventilation of dry air, Resonant frequency, Tobacco smoke
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-91339 (URN)10.1007/s00408-012-9448-y (DOI)000316570900005 ()
Note

Funding Agencies|Futurum||Academy of Healthcare||Jonkoping County Council||FORSS||Medical Research Council of Southeast Sweden||

Available from: 2013-04-22 Created: 2013-04-22 Last updated: 2017-12-06
Schmekel, B., Blomstrand, P. & Venge, P. (2013). Serum lysozyme a surrogate marker of pulmonary microvascular injury in smokers?. Clinical Physiology and Functional Imaging, 33(4), 307-312
Open this publication in new window or tab >>Serum lysozyme a surrogate marker of pulmonary microvascular injury in smokers?
2013 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 33, no 4, p. 307-312Article in journal (Refereed) Published
Abstract [en]

Progression rate of disease processes in smoke-induced lung injuries varies greatly. Diverse pathophysiological mechanisms may trigger these divergences. The aim of this study was to evaluate whether circulating markers of monocytes/macrophages and/or neutrophil [i.e. lysozyme (LZM) or myeloperoxidase (MPO)] were associated with reduced values of diffusion capacity (DL,CO), which is considered to serve as a mirror of pulmonary microvascular derangement and an early sign of tissue remodelling in smokers. Data obtained from 134 smokers (GOLD stage 1) and 24 matched healthy non-smoking volunteers were evaluated in a cross-sectional study design. Lung function tests as well as single breath test of DL,CO were assessed according to ATS/ERS guidelines. Biomarkers were measured in serum by means of sensitive immunoassays. A subgroup of smokers with normal lung function was created to minimize confounding, by excluding datasets showing significant airflow limitation and abnormally high values of carboxy haemoglobin (COHb), the latter indicating recent smoking. The capacity of serum lysozyme to correctly identify abnormally low values of DL,CO (i.e. andlt;1 center dot 9SD units), tended to be higher than that of Myeloperoxidase as assessed by analyses of receiver operated curves (ROC; AUC 0 center dot 81, 95%CI: 0 center dot 690 center dot 89 versus AUC 0 center dot 67, 95%CI: 0 center dot 600 center dot 81). It is concluded that serum levels of lysozyme, reflecting mainly activated monocytes/macrophages but also neutrophils, were significantly associated with isolated decrements of DL,CO in smokers with normal lung function tests. This suggests monocytes/macrophages to have a significant mechanistic role in early phases of the disease process and/or pulmonary microvascular damage.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2013
Keywords
biomarkers in serum, diffusion capacity, tobacco smokers
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-94592 (URN)10.1111/cpf.12029 (DOI)000319293100010 ()
Note

Funding Agencies|Futurum the Academy of Healthcare||Jonkopings County Council||FORSS the Medical Research Council of Southeast Sweden||

Available from: 2013-06-27 Created: 2013-06-27 Last updated: 2017-12-06
Norberg, P., Persson, L., Schmekel, B., Sandborg, M., Kentson, M. & Gustafsson, A. (2012). The potential of quantitative lung SPECT in identifying humans with COPD using the CVT-method: a Pilot Study of advance disease. Paper presented at EANM, Milano, Italy, 27–31 oktober 2012.
Open this publication in new window or tab >>The potential of quantitative lung SPECT in identifying humans with COPD using the CVT-method: a Pilot Study of advance disease
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2012 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-91092 (URN)
Conference
EANM, Milano, Italy, 27–31 oktober 2012
Available from: 2013-04-15 Created: 2013-04-15 Last updated: 2013-09-05
Davidsson, A. & Schmekel, B. (2010). Efficacy of two breath condensers. Journal of clinical laboratory analysis (Print), 24(4), 219-223
Open this publication in new window or tab >>Efficacy of two breath condensers
2010 (English)In: Journal of clinical laboratory analysis (Print), ISSN 0887-8013, E-ISSN 1098-2825, Vol. 24, no 4, p. 219-223Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Examination of Exhaled Breath Condensate has been suggested to give information about inflammatory airway diseases. OBJECTIVES: The aim was to compare efficacy and variability in gain of two commercially available exhaled breath condensers, ECoScreen and RTube in an in vitro set up. METHODS: Test fluids containing myeloperoxidase (MPO) or human neutrophil lipocalin (HNL) in addition to saline and bovine serum albumin were nebulized and aerosols were transferred by a servo ventilator to either of the two condensers. Analyses of MPO, HNL, or chlorine were done by means of ELISA, RIA, or a modified adsorbed organic halogen technique (AOX), respectively. RESULTS: Recoveries of HNL were higher when using ECoScreen than RTube (Pandlt;0.05). In contrast, there were no significant differences between the two condensers in recoveries of MPO or chlorine. The spread of data was wide regarding all tested compounds. CONCLUSION: Variability in gain was large and ECoScreen was more efficacious then RTube in condensing the tested solutes of HNL, but not those of MPO or chlorine.

Keywords
Chlorine, HNL, MPO, exhaled breath condensate, efficacy
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-58821 (URN)10.1002/jcla.20389 (DOI)
Available from: 2010-08-27 Created: 2010-08-27 Last updated: 2017-12-12
Davidsson, A., Stratelis, G., Acevedo, F. & Schmekel, B. (2008). Can we predict development of COPD?.
Open this publication in new window or tab >>Can we predict development of COPD?
2008 (English)Article in journal (Refereed) Submitted
Abstract [en]

Background: Cigarette smoking is one of the main causes of chronic obstructive pulmonarydisease (COPD). Chronic inflammation of airways may start years before manifestation ofclinical symptoms, thus early identification of smokers at risk to develop COPD is crucial.Objectives: To evaluate if a single breath test for diffusion capacity (DLCO) or concentrationsof certain biomarkers in exhaled breath condensate (EBC), saliva or serum could identifysubjects with COPD or non-COPD smokers and ex-smokers supposed to be at risk to developCOPD, as suggested by rapid decline of forced expiratory volume in one second (FEV1) during afive year period.

Methods: Twenty-nine symptom free smokers/ex-smokers, 16 smokers/ex-smokers with COPDand 19 matched healthy non-smoking volunteers were studied by means of spirometry, DLCO,and analyses of EBC, saliva and serum [chlorine, lysozyme, eosinophil cationic protein (ECP)and myeloperoxidase (MPO)]. Area under a receiver operated curve (AUCROC) was used toassess sensitivity and specificity of measurements to identify manifest or risk to get COPD.

Results: Only DLCO could identify subjects with COPD or risk to develop COPD, as judged byAUCROC (0.85 or 0.75, respectively). Lower DLCO (p=0.003) and higher serum concentrationsof lysozyme (p=0.011) were recorded in those with COPD than non-COPD subjects.Furthermore, concentration of chlorine was higher in EBC from COPD subjects than fromhealthy volunteers (p<0.05). Except for chlorine, none of the remaining biomarkers weredetected in EBC and there was a vast variability of concentrations of biomarkers in saliva.

Conclusion: DLCO was the most effective discriminator of COPD and rapid decline of lungfunction. Serum concentration of lysozyme was the second strongest discriminator, confirmingprevious findings on involvement of neutrophils in the disease process. The use of EBC as a toolto measure exhaled biomarkers involved in COPD is dubious due to large variability and lowconcentrations of markers in EBC.

Keywords
Exhaled Breath Condensate, serum, DLCO, COPD, lysozyme and chlorine
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-16293 (URN)
Available from: 2009-01-13 Created: 2009-01-13 Last updated: 2009-09-18Bibliographically approved
Davidsson, A., Naidu Sjöswärd, K. & Schmekel, B. (2008). Efficacy of Two Breath Condensers: An in Vitro Comparative Study.
Open this publication in new window or tab >>Efficacy of Two Breath Condensers: An in Vitro Comparative Study
2008 (English)Article in journal (Refereed) Submitted
Abstract [en]

Examination of exhaled breath condensate (EBC) has been suggested to give information about inflammatory airway diseases.

The aim of the present study was to compare efficacy and variability in gain of two commercially available condensers, ECoScreen® [E] and RTube [R] in an in vitro experimental set up.

Methods: Test-fluids containing myeloperoxidase (MPO) or human neutrophil lipocalin (HNL) in addition to saline and bovine serum albumin (BSA) were nebulized. The aerosol was intermittently driven forward by a servoventilator fed by room tempered air, to reach the condenser. Two different concentrations of saline were also dispensed via the same equipment. Analyses of MPO, HNL and chlorine were done by means of ELISA, RIA or a modified adsorbed organic halogen technique (AOX), respectively.

Results: Significantly higher volumes were recovered by ECoScreen than by RTube during 20-minutes experiments (p<0.001) but not in ten-minute experiments (p>0.05). Based on changes of source concentrations in the nebulizer cup, resulting from nebulization per se, recoveries of HNL tended to be higher by E than by R (p<0.05). In contrast there were no significant differences between condensers in recoveries of MPO or chlorine. The spread of data was wide regarding all tested compounds and of similar degree for both condensers, despite acceptable inter-assay coefficients of variations of all analyses.

Conclusion: Condensing efficacy tended to be larger using E than R but there was a large variability in results from both condensers. Individual biomolecules may have their specific characteristics, and this must be taken into consideration when planning studies on EBC. We suggest that further methodological studies of the EBC method are warranted.

Keywords
Chlorine, HNL, MPO, Exhaled Breath Condensate, efficacy
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-16292 (URN)
Available from: 2009-01-13 Created: 2009-01-13 Last updated: 2009-08-17Bibliographically approved
Stratelis, G., Fransson, S. G., Schmekel, B., Jakobsson, P. & Mölstad, S. (2008). High prevalence of emphysema and its association with BMI: A study of smokers with normal spirometry. Scandinavian Journal of Primary Health Care, 26(4), 241-247
Open this publication in new window or tab >>High prevalence of emphysema and its association with BMI: A study of smokers with normal spirometry
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2008 (English)In: Scandinavian Journal of Primary Health Care, ISSN 0281-3432, E-ISSN 1502-7724, Vol. 26, no 4, p. 241-247Article in journal (Refereed) Published
Abstract [en]

Objectives: To evaluate to what extent emphysema was evident, as identified by High Resolution Computed Tomography (HRCT), in smokers with normal lung function and to relate age, gender, smoking history, and body mass index (BMI) to the HRCT results. A secondary aim was to study to what extent emphysema was present in smokers with lower normal values of lung function defined as FEV1/FVC ratio percentage of predicted value (89-93% of predicted value for males and 90-93% for females) or FEF50 60% of predicted compared with smokers without this definition.

Methods: Fifty-nine smokers, with a mean age of 53 years and with normal lung function, were examined with HRCT.

Results: Emphysema evidenced visually by HRCT was present in 43% of the subjects. Using a 0-5 grade scale (0=normal finding; 5=emphysema in most slices), the degree of emphysema was almost exclusively 3-4. The type of emphysema was distributed as centrilobular emphysema predominant in 43.5%, paraseptal emphysema predominant in 43.5%, and as an equal mixture of these types in 13%. The presence of emphysema did not differ between the group of smokers with lower normal values of lung function and the rest of the smokers. Smokers with emphysema had significantly lower BMI than those devoid of emphysema, 24 and 27 respectively (p0.0011).

Conclusion: There was a high occurrence of visual emphysema in middle-aged smokers with normal lung function. The densitometric quantitative analysis method is inadequate for detecting mild emphysema. High prevalence of emphysema was associated with low BMI.

Keywords
Body mass index, computed tomography, family practice, pulmonary emphysema, smoking, spirometry
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-16159 (URN)10.1080/02813430802452732 (DOI)
Available from: 2009-01-08 Created: 2009-01-07 Last updated: 2017-12-14
Davidsson, A., Söderström, M., Naidu Sjöswärd, K. & Schmekel, B. (2007). Chlorine in Breath Condensate: A Measure of Airway Affection in Pollinosis?. Respiration, 74(2), 184-191
Open this publication in new window or tab >>Chlorine in Breath Condensate: A Measure of Airway Affection in Pollinosis?
2007 (English)In: Respiration, ISSN 0025-7931, E-ISSN 1423-0356, Vol. 74, no 2, p. 184-191Article in journal (Refereed) Published
Abstract [en]

Background: Infiltration of inflammatory cells in bronchial mucosa and glandular hypersecretion are hallmarks of asthma. It has been postulated that exhaled breath condensate (EBC) mirrors events in epithelial lining fluid of airways, such as presence of local inflammation as well as glandular hypersecretion. It is also well known that eosinophil cationic protein (ECP) and cysteinyl-leukotrienes (cys-LT) are released by circulating inflammatory cells when triggered by antigen stimulation in asthma patients.

Objectives: The aim of this study was to evaluate whether chlorine and/or cys-LT in EBC would reflect changes of exposure of airborne pollen in patients with asthma.

Methods: EBC and serum were collected from 23 patients with allergic asthma during a pollen season and repeated 5 months later during a period with no aeroallergens. Chlorine was measured by means of a sensitive coulometric technique and cys-LT by an EIA technique. Serum ECP was measured and lung function tests were performed and symptoms noted during both occasions.

Results: Significantly higher concentrations of chlorine in EBC (p = 0.007) and ECP in serum (p = 0.003) were found during the pollen season compared to post-season. Chlorine levels tended to be higher in patients who reported of chest symptoms compared to those who denied symptoms during the pollen season (p = 0.06). Areas under the receiver-operated characteristic curves (AUCROC) were compared and similar discriminative power to identify exacerbations of asthma was recorded by chlorine in EBC (range 0.67-0.78) and ECP in serum (range 0.64-0.78).

Conclusion: It is concluded that chlorine in EBC and ECP in serum decreased significantly post-season, and this is suggested to mirror the decrement in airborne antigen. It is furthermore proposed that chlorine in EBC and ECP in serum tend to have a similar capacity to identify seasonal variations in airborne pollen in patients with asthma.

Place, publisher, year, edition, pages
Karger, 2007
Keywords
Pollen season, Allergic asthma, Exhaled breath condensate, Serum eosinophil cationic protein, Chlorine
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-16291 (URN)10.1159/000091300 (DOI)000244565600010 ()
Available from: 2009-01-13 Created: 2009-01-13 Last updated: 2017-12-14Bibliographically approved
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