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O Holz

Publications and source records attributed to O Holz.

At least 19 recordsLinked to original sources
PubMed2006

Lung fibroblasts from patients with emphysema show markers of senescence in vitro.

BACKGROUND: The loss of alveolar walls is a hallmark of emphysema. As fibroblasts play an important role in the maintenance of alveolar structure, a change in fibroblast phenotype could be involved in the pathogenesis of this disease. In a previous study we found a reduced in vitro proliferation rate and number of population doublings of parenchymal lung fibroblasts from patients with emphysema and we hypothesized that these findings could be related to a premature cellular aging of these cells. In this study, we therefore compared cellular senescence markers and expression of respective genes between lung fibroblasts from patients with emphysema and control patients without COPD. METHODS: Primary lung fibroblasts were obtained from 13 patients with moderate to severe lung emphysema (E) and 15 controls (C) undergoing surgery for lung tumor resection or volume reduction (n = 2). Fibroblasts (8E/9C) were stained for senescence-associated beta-galactosidase (SA-beta-Gal). In independent cultures, DNA from lung fibroblasts (7E/8C) was assessed for mean telomere length. Two exploratory 12 k cDNA microarrays were used to assess gene expression in pooled fibroblasts (3E/3C). Subsequently, expression of selected genes was evaluated by quantitative PCR (qPCR) in fibroblasts of individual patients (10E/9C) and protein concentration was analyzed in the cell culture supernatant. RESULTS: The median (quartiles) percentage of fibroblasts positive for SA-beta-Gal was 4.4 (3.2;4.7) % in controls and 16.0 (10.0;24.8) % in emphysema (p = 0.001), while telomere length was not different. Among the candidates for differentially expressed genes in the array (factor > or = 3), 15 were upregulated and 121 downregulated in emphysema. qPCR confirmed the upregulation of insulin-like growth factor-binding protein (IGFBP)-3 and IGFBP-rP1 (p = 0.029, p = 0.0002), while expression of IGFBP-5, -rP2 (CTGF), -rP4 (Cyr61), FOSL1, LOXL2, OAZ1 and CDK4 was not different between groups. In line with the gene expression we found increased cell culture supernatant concentrations of IGFBP-3 (p = 0.006) in emphysema. CONCLUSION: These data support the hypothesis that premature aging of lung fibroblasts occurs in emphysema, via a telomere-independent mechanism. The upregulation of the senescence-associated IGFBP-3 and -rP1 in emphysema suggests that inhibition of the action of insulin and insulin-like growth factors could be involved in the reduced in vitro-proliferation rate.

Biomarkers↗
PubMed2006

Time course of exhaled hydrogen peroxide and nitric oxide during chemotherapy.

This study was designed to assess the effect of differential leukocyte depletion during chemotherapy by monitoring the levels of exhaled hydrogen peroxide H2O2 and nitric oxide (F(eNO)) present. In 39 patients with lung cancer (chronic obstructive pulmonary disorder up to stage II, median forced expiratory volume in one second 78% predicted), measurements were performed before a cycle of therapy (day 1), at least once during the cycle (day 8: n = 34; day 15: n = 19), and afterwards (days 21-29). There were significant changes in the level of H2O2, F(eNO) and peripheral blood cell differentials over the visits. The level of H2O2 was decreased only on day 15, with a median (difference between the upper and lower quartiles) fall of 31 (57)%, while F(eNO) was reduced only on day 8, by 22 (40)%. Neutrophil numbers were unchanged on day 8 and decreased by 59 (48)% on day 15, while monocyte numbers were decreased on day 8 by 87 (39)%. On days 21-29, values had returned to baseline. Taken together with previous findings, the parallel course of levels of exhaled hydrogen peroxide and neutrophil counts suggests that a major part of exhaled hydrogen peroxide is due to neutrophils via the conducting airways. In contrast, the production of exhaled nitric oxide seems to be primarily associated with monocytes.

Exhalation↗
PubMed2004

Comparison of exhaled nitric oxide analysers.

Currently no published data are available concerning the comparability of different types of NO analysers, making inter-laboratory comparisons difficult. In two sets of experiments we compared 4 and 5 NO analysers, respectively, from 3 different manufacturers using different calibration regimes: calibration with (1) a separate recommended calibration gas for each analyser, (2) a single low concentration for all (394 ppb), and (3) a single high concentration (12.8 ppm). We measured three subjects with known low (L), moderate (M) and high (H) bronchial exhaled nitric oxide concentrations as well as standard gases (SG). In the first set of experiments, calibration regime 1 resulted in the largest differences between analysers (coefficient of variation (CV) for L, M, H, SG: 0.42, 0.22, 0.20, 0.14). The lowest CV between analysers was observed after calibration 2 (0.34, 0.19, 0.12, 0.02). Very similar results were obtained in the second set of comparisons. Thus, differences between analysers existed, but were mainly due to differences in recommended calibration gases/procedures. Only a small part was explainable by deviations from target flow. These differences need to be taken into account when comparing data between laboratories or replacing the calibration gas of an analyser, as well as for the establishment and interpretation of normal values.

Adult↗
PubMed2004

Direct measurement of BDP and 17-BMP in bronchial and peripheral lung tissue after inhalation of HFA- vs CFC-driven aerosols.

Indirect assessments have shown a superior lung deposition of HFA-BDP (Ventolair/Qvar) compared to CFC-BDP (Aerobec). The aim of this study was to assess the concentrations of BDP and its metabolite 17-BMP in airways and peripheral tissue from resected lung specimens after inhalation of these BDP formulations. Immediately prior to surgery for lung cancer, 10 patients inhaled 1000 microg of either CFC-BDP (n = 5) or HFA-BDP (n = 5) Mouthwash was collected after inhalation, and serum before, during, and after surgery. There was no significant difference between CFC and HFA in the concentration of 17-BMP in bronchi (median, 4365 vs 4121 pg/g tissue). After CFC, concentrations of 17-BMP were lower in peripheral tissue (1424 vs 2089 pg/g; ANCOVA, p = 0.001) and in serum taken immediately after inhalation (688 vs 1219 pg/ml, p < 0.01). Furthermore, the CFC group showed a higher concentration of BDP in the mouthwash (17,660 vs 1320 ng/ml, p < 0.05), but the concentration of 17-BMP was lower (452 vs 1028 ng/ml, n.s.). These findings indicate a predominantly peripheral deposition of HFA-BDP, in line with previous data. They also provide evidence for a faster uptake and metabolism of HFA-BDP, probably because BDP is dissolved in HFA and has a smaller particle size distribution than the CFC suspensions.

Administration, Inhalation↗
PubMed2004

[Non-invasive methods for monitoring airway inflammation: a comparison of expenditures, gain and clinical value].

Among the noninvasive procedures for the assessment of airway inflammation, the analysis of spontaneous sputum is currently the only method, the expenses of which are covered by health insurance in Germany. It can easily be used for semiquantitive cytological analyses by practising pneumologists. Recent data also indicate the usefulness of sputum induction, particularly in asthma diagnosis and therapy control, and demonstrate its capability of reducing total costs per patient. In contrast to sputum analysis, the measurement of exhaled nitric oxide (NO) yields a read-out without time delay. NO as associated with eosinophils also seems suitable for monitoring airway inflammation. The number of studies regarding NO, both its pathophysiological role and clinical use, is far greater than that regarding any other marker of exhaled air. Measurements are easy and fast, but the costs of analysers are still prohibitive in clinical practice. The analysis of other compounds of exhaled air, particularly those of exhaled breath condensate (EBC), offers fascinating perspectives, owing to the scope of markers that might be measured, and could enable the assessment of multivariate profiles that are useful for diagnosis and therapy control. Currently, however, the method still faces methodological questions, and data indicating its usefulness and cost-efficiency in clinical practice are scarce. Compared to NO, the expenses per measurement in clinical use are mainly due to the costs per marker detection after sampling, as well as storage and transport of samples. The on-site analysis of pH in the EBC could be a first step to circumvent this obstacle.

Airway Obstruction↗
PubMed2004

Effect of freezing of sputum samples on flow cytometric analysis of lymphocyte subsets.

Sputum samples should be processed shortly after induction to prevent cell degradation. For intermediate storage, freezing of homogenised samples or immediate fixation have been shown to be suitable for cytospins. The aim of this study was to investigate whether freezing or immediate fixation of sputum affect the analysis of lymphocyte subsets by flow cytometry. Selected plugs from 24 sputum samples were homogenised. One aliquot was processed immediately and analysed by flow cytometry. A second aliquot was homogenised, frozen at -20 C after addition of dimethylsulfoxide and stored for a median time of 6 days. In six samples a third aliquot was fixed in formalin after induction and stored for up to 72 h before further processing. Compared to immediate processing, percentages of total lymphocytes and T-suppressor cells were elevated after being frozen, with a minor decrease in the T4/T8 ratio. Proportions of total lymphocytes, T-helper and T-suppressor cells correlated between native and frozen samples, intra-class correlation coefficients being 0.74, 0.85 and 0.70, respectively. The formalin-fixed aliquots could not be analysed with the antibodies used. In conclusion, freezing seems to be a suitable technique to store sputum samples for flow cytometry of CD3, CD4 and CD8 lymphocyte subsets. Its effects were minor compared to the variation between subjects.

Adult↗
PubMed2004

Lung fibroblasts from patients with emphysema show a reduced proliferation rate in culture.

Emphysema is characterised by a loss of alveolar structure, as reflected in elastic recoil and gas exchange. As fibroblasts play a key role in the maintenance of structure, the current authors hypothesised that their proliferation might be constitutively impaired in lung emphysema. Using explant cultures, lung fibroblasts were obtained from resected lungs of 10 patients with emphysema (median forced expiratory volume in one second (FEV1) 40% predicted) and 10 control patients (FEV1, 95% pred). The doubling time (DT) was measured over 4 days under standard conditions (10% foetal calf serum) prior and after cryopreservation. Additionally, in seven samples per group the total population doubling level (PDL) was determined. In emphysema, mean+/-sem DT was 33.6+/-2.8 h compared with 24.8+/-1.4 h in controls. The differences in DT were preserved after cryopreservation. Groups also differed in the initial slope of the PDL plot during long-term culture (up to 35 days). However, the median (range) maximum PDL did not differ significantly between groups (13.8 (7.4-22.6) versus 20.2 (11.2-25.5)). The current authors, therefore, suggest that the reduced proliferation rate in vitro of lung fibroblasts from patients with emphysema reflects a persistent, intrinsic failure of cellular replacement and maintenance in this disease, possibly in relation to pre-term aging.

Aged↗
PubMed2002

The relationship between airway hyper-responsiveness, markers of inflammation and lung function depends on the duration of the asthmatic disease.

BACKGROUND: The combination of airway hyper-responsiveness, eosinophilic airway inflammation, and lung function impairment is considered as a hallmark of bronchial asthma. Since airway function might change with time in chronic asthma, the association between parameters which are characteristic of asthma could be different in subjects with different durations of the disease. OBJECTIVE: We assessed whether in patients with asthma the relationship between airway hyperresponsiveness, non-invasive markers of airway inflammation, and baseline lung function depended on the duration of the disease. METHODS: Sixty-six non-smoking patients with mild to moderate allergic asthma without corticosteroids were assigned to two groups, according to a duration of the disease (time interval since doctor's diagnosis) of either < or = 16 years (median 8 years; mean FEV1, 92.6% pred.; n = 34) or > 16 year (median 25 years; mean FEV1, 87.9% pred.; n = 32). RESULTS: Groups did not differ statistically in PC20FEV1 of methacholine, sputum composition, levels of exhaled nitric oxide (NO), lung function parameters, or history of treatment. There were significant correlations between PC20FEV1, eosinophils and NO in patients with a duration of the disease < or = 16 year, but no relation to lung function. In contrast, patients with a duration > 16 year showed a correlation between PC20FEV1 of methacholine and lung function but not eosinophils or NO. In both groups, eosinophils and NO were associated with each other. These results were corroborated by the statistical procedure of factor analysis that revealed 'inflammation' and 'lung function' as major entities and found 'responsiveness' to be associated with only one of them in each group. CONCLUSION: Our data demonstrate that with a shorter duration of the asthmatic disease airway hyper-responsiveness is associated with airway inflammation, whereas with a longer duration it is associated with impaired lung function, suggesting that in chronic asthma ongoing alterations become the primary determinant of functional characteristics.

Adult↗
PubMed2002

Repeated ozone exposures enhance bronchial allergen responses in subjects with rhinitis or asthma.

BACKGROUND: Single exposures to > 200 p.p.b. of ozone are capable of enhancing the early-phase lung function response to allergen. OBJECTIVE: The aim of the present study was to compare the effect of single vs. repeated exposures to ozone on early and late-phase allergen responses. METHODS: Eleven subjects with allergic asthma and 22 subjects with allergic rhinitis underwent single exposures to filtered air, 125 p.p.b. and 250 p.p.b. ozone, as well as repeated exposures to 125 p.p.b. ozone on four consecutive days. Twenty hours after the (final) exposure, subjects inhaled a single dose of allergen and a sputum induction was performed 6-7 h later. RESULTS: In the subjects with rhinitis, the mean early-phase response of FEV1 and the number of > or = 20% reductions were significantly greater after exposure to 250 or 4 x 125 p.p.b. ozone compared with filtered air. In addition, most of the > or = 15% late-phase responses in FEV1 occurred after exposure to 4 x 125 p.p.b., as well as the strongest effects on sputum parameters. The rise in the number of eosinophils was statistically significant in both groups. Regarding the number of lymphocytes and the concentrations of mast cell tryptase, histamine or LDH, significance was, however, only reached in the asthma group. CONCLUSION: Our data suggest that repeated exposure to ozone, at a peak ambient air level, can enhance both functional and inflammatory responses to inhaled allergen in subjects with pre-existing allergic airway diseases, and that these effects might reach a clinically relevant magnitude.

Adult↗
PubMed2002

Sputum induction.

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Administration, Inhalation↗
PubMed2001

Airway response to inhaled hypertonic saline in patients with moderate to severe chronic obstructive pulmonary disease.

The present study aimed at delineating the mechanisms underlying the adverse response to hypertonic saline inhalation in patients with chronic obstructive pulmonary disease (COPD). Twenty patients (age, 48-70 yr; FEV(1), 29-58 %pred) inhaled, on two different days in randomized order, 200 microg salbutamol from an MDI and 20 min later either 0.9% or 3% saline from an ultrasonic nebulizer for a maximum of four consecutive 5-min periods. Forced expiratory (FEV(1)) and inspiratory (FIV(1)) volumes, inspiratory capacity (IC), intrathoracic gas volume (ITGV), and specific airway resistance (SRaw) were measured. Significant changes occurred in FEV(1), FIV(1), IC, ITGV, and SRaw with both concentrations (p < 0.05, each) and effects were stronger with 3% as compared with 0.9% saline (p < 0.05, each). The increase in dyspnea was associated with the changes in FIV(1), FEV(1), IC, and ITGV, in contrast to its decrease during bronchodilation, where only FIV(1) was important. Sputum analysis showed elevated concentrations of histamine after 3% as compared with 0.9% saline. These data indicate that the adverse lung function response to hypertonic saline is common in patients with moderate to severe COPD, involves both bronchoconstriction and lung hyperinflation, and could be mediated, at least partially, through activation of mast cells.

Administration, Inhalation↗
PubMed2001

Flow cytometric analysis of lymphocyte subpopulations in bronchoalveolar lavage fluid after repeated ozone exposure.

As known from studies in animal and human subjects, ozone can exert effects on the immune response including allergic sensitisation and allergen responsiveness. The objective of the present study was to assess the changes in lymphocyte subsets in bronchoalveolar lavage fluid (BALF) after single and repeated ozone exposures. Twenty-three healthy subjects underwent single exposures to 200 ppb ozone or filtered air (FA), as well as repeated exposures to 200 ppb ozone on four consecutive days, each during 4 h of intermittent exercise. Bronchoalveolar lavage was performed 20 h after the single exposure or the last of the repeated exposures. Lymphocytes were identified by sideward scatter and CD45 expression, and their subsets by eight different panels of antibodies. Checksums were calculated to assess the validity of the results. The percentage and the absolute number of lymphocytes, mostly comprising T-lymphocytes (CD2+; overall mean 98.8%), increased after single (P < 0.05; each), but not after repeated ozone exposure, compared with FA (7.4 vs 5.8 vs 6.5%; 680 vs 419 vs 301 x 10(3)). In addition, we observed small but statistically significant changes in the proportions of lymphocyte subpopulations. The percentage of CD4+ lymphocytes increased after single (P < 0.05) and repeated ozone exposure (P < 0.01), whereas the percentage of CD8+ cells decreased after repeated exposure (P < 0.05). The proportion of activated lymphocytes (CD25+) was elevated after repeated, compared with single, ozone exposure (P < 0.01), and the percentages of natural killer (NK) cells were decreased after both single (P < 0.05) and repeated (P < 0.01) exposures. Our data suggest that single but not repeated ozone exposures cause a change in absolute numbers of lymphocytes in BALF, whereas the proportions of lymphocyte subsets are affected by single as well as repeated exposures.

Adult↗
PubMed2001

Freezing of homogenized sputum samples for intermittent storage.

BACKGROUND: Among the reasons that restrict the application of sputum induction in outpatient settings is the need for processing of samples within 2 h after induction. OBJECTIVE: The aim of our study was to assess whether freezing is suitable for intermediate storage of sputum samples before processing. METHODS: We compared differential cell counts between two sputum aliquots derived from the same sample. One aliquot was processed within 2 h after production and one, after it had been frozen under addition of dimethyl-sulfoxid (DMSO) and stored up to 10 days at -20 degrees C. Thirty-five samples were frozen immediately prior to preparation of cytospins, and 10 samples were frozen at an even earlier stage, directly after homogenization. RESULTS: In both sets of experiments we observed a significant relationship between frozen and native samples regarding macrophages, neutrophils and eosinophils, as indicated by respective intraclass correlation coefficients of 0.96, 0.96, and 0.93 in the first, and of 0.92, 0.96 and 0.77 in the second experiments. CONCLUSION: Our results indicate that the freezing of sputum samples at different stages of processing does not alter sputum morphology to an extent that affects the results of differential cell counts.

Adult↗
PubMed2000

Update on sputum methodology.

Over the past few years cellular and biochemical sputum examinations have become important instruments to assess airway inflammation. The aim of this review is to summarize new methodological developments and aspects, which are currently under investigation. The use of isotonic saline has increased safety of inductions in patients with severe asthma and in children. The origin of sputum is better understood, as is the need to standardize the volume and duration of induction. It also needs to be borne in mind that the induction procedure itself is able to cause changes in sputum composition. However, the basic induction and processing procedures have not changed much over the last few years, and therefore the method is still time consuming. The analysis of ECP in lysed sputum cells as a marker for the number of eosinophils has been suggested to overcome this problem, but needs further validation. Furthermore, storage of sputum has been studied, as well as early fixation or freezing of sputum cells to elongate the time between induction and processing. Differential cell counts by flow cytometry are still difficult, but the method has increased knowledge concerning lymphocyte subsets and the activation status of sputum cells. The use of induced sputum to noninvasively measure airway inflammation in clinical trials will offer additional information, but the proper use and interpretation of sputum outcome parameters will need further investigation.

Administration, Inhalation↗
PubMed2000

The concentration of hydrogen peroxide in exhaled air depends on expiratory flow rate.

Hydrogen peroxide (H2O2) is known to be detectable in exhaled air. The present study aimed to determine whether the concentration of exhaled H2O2 depends on expiratory flow rate in order to make inferences on the site of its production within the lung. Breath condensate was collected in cooled Teflon tubes, at three different expiratorv flow rates, in 15 healthy or mild asthmatic subjects. Tests were repeated 2-5 times to assess reproducibility. Mean+/-SEM concentrations of H2O2 at flow rates of 140, 69 and 48 mL.s(-1) were 0.12+/-0.02, 0.19+/-0.02 and 0.32+/-0.03 microM, respectively. These values differed significantly from each other (p<0.001). For comparison, average coefficients of variability within repeated measurements at each of the three flow rates were 68, 62 and 82%, respectively. These data demonstrate that the concentration of exhaled hydrogen peroxide depends on expiratory flow rate. Since flow dependence is an indicator of production within the airways, this result suggests that, to a large extent, the exhaled hydrogen peroxide originates within the airways. However, even under strictly controlled conditions, a high degree of variability persists, which may limit the usefulness of exhaled hydrogen peroxide as a marker of airway inflammation.

Adult↗
PubMed2000

Noninvasive methods to measure airway inflammation: future considerations.

This last contribution to the series focuses on open questions regarding: 1) methodological issues; and 2) the potential clinical application of the noninvasive methods such as induced sputum and the analysis of exhaled air for the assessment of airway inflammation. In addition their potential future role in occupational health and the early diagnosis of neoplastic lesions are briefly discussed. The future clinical application of noninvasive methods will depend on the progress made to improve their practicability, particularly in rendering them less time consuming and cheaper. To assess their clinical value, prospective studies are needed to establish whether patients actually benefit from the results obtained. This is also important to implement the methods into the healthcare system and to obtain adequate financial compensation. Therefore, it is necessary to know: 1) whether the assessment of airwav inflammation can aid in coming to an earlier and better defined diagnosis; 2) whether by repeated monitoring it is possible to avoid exacerbations through earlier interventions; and 3) whether the long-term outcome of patients is improved through knowledge of the type and degree of airway inflammation that is taken into account in selecting the appropriate treatment. In the meantime a wealth of data has become available, both for induced sputum and the analysis of exhaled air, which give these methods the potential to be incorporated into future clinical practice. This, however, will, amongst the other issues, depend on favourable cost-benefit ratios which should also be the subject of future prospective studies.

Breath Tests↗