C Witt

Charité Universitätsmedizin Berlin, Berlin, Land Berlin, Germany

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Publications (127)358.73 Total impact

  • Pneumologie 03/2011; 65(S 01).
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    ABSTRACT: This study aimed to show that SHOX2 DNA methylation is a tumor marker in patients with suspected lung cancer by using bronchial fluid aspirated during bronchoscopy. Such a biomarker would be clinically valuable, especially when, following the first bronchoscopy, a final diagnosis cannot be established by histology or cytology. A test with a low false positive rate can reduce the need for further invasive and costly procedures and ensure early treatment. Marker discovery was carried out by differential methylation hybridization (DMH) and real-time PCR. The real-time PCR based HeavyMethyl technology was used for quantitative analysis of DNA methylation of SHOX2 using bronchial aspirates from two clinical centres in a case-control study. Fresh-frozen and Saccomanno-fixed samples were used to show the tumor marker performance in different sample types of clinical relevance. Valid measurements were obtained from a total of 523 patient samples (242 controls, 281 cases). DNA methylation of SHOX2 allowed to distinguish between malignant and benign lung disease, i.e. abscesses, infections, obstructive lung diseases, sarcoidosis, scleroderma, stenoses, at high specificity (68% sensitivity [95% CI 62-73%], 95% specificity [95% CI 91-97%]). Hypermethylation of SHOX2 in bronchial aspirates appears to be a clinically useful tumor marker for identifying subjects with lung carcinoma, especially if histological and cytological findings after bronchoscopy are ambiguous.
    BMC Cancer 11/2010; 10:600. · 3.32 Impact Factor
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    ABSTRACT: Cytologic examination of specimens obtained from the respiratory tract is a lung cancer diagnostic procedure with high specificity but moderate sensitivity. The use of molecular biomarkers may enhance the sensitivity of cytologic examination in the detection of lung cancer. Complement factor H, a protein secreted by lung cancer cells, was quantified in a series of bronchoalveolar lavage supernatants from lung cancer patients and patients with nonmalignant respiratory diseases. Albumin, total protein content, and hemoglobin were also analyzed. Results were validated in independent sets of bronchoalveolar lavage and sputum supernatants. There was a significantly higher concentration of factor H in bronchoalveolar lavage samples from lung cancer patients. The sensitivity and specificity of the factor H test was 82% and 77%, respectively. These results were validated in an independent set of patients with nearly identical results. Furthermore, 70% and 45% of bronchoalveolar lavage fluids from central and peripheral tumors, respectively, reported as cytologically negative, were classified as positive using this marker. Finally, the test was evaluated in a series of sputum supernatants from lung cancer patients and controls. The sensitivity and specificity of the factor H test in this series was 80% and 88%, respectively. Factor H is elevated in bronchoalveolar lavage and sputum from lung cancer patients. Measurement of molecular biomarkers, such as complement factor H, may be used in the future as an adjunct to cytology in the diagnosis of malignant pulmonary diseases.
    Cancer Epidemiology Biomarkers & Prevention 10/2010; 19(10):2665-72. · 4.56 Impact Factor
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    ABSTRACT: Due to an increasing awareness of the potential hazardousness of air pollutants, new laws, rules and guidelines have recently been implemented globally. In this respect, numerous studies have addressed traffic-related exposure to particulate matter using stationary technology so far. By contrast, only few studies used the advanced technology of mobile exposure analysis. The Mobile Air Quality Study (MAQS) addresses the issue of air pollutant exposure by combining advanced high-granularity spatial-temporal analysis with vehicle-mounted, person-mounted and roadside sensors. The MAQS-platform will be used by international collaborators in order 1) to assess air pollutant exposure in relation to road structure, 2) to assess air pollutant exposure in relation to traffic density, 3) to assess air pollutant exposure in relation to weather conditions, 4) to compare exposure within vehicles between front and back seat (children) positions, and 5) to evaluate "traffic zone"-exposure in relation to non-"traffic zone"-exposure.Primarily, the MAQS-platform will focus on particulate matter. With the establishment of advanced mobile analysis tools, it is planed to extend the analysis to other pollutants including NO2, SO2, nanoparticles and ozone.
    Journal of Occupational Medicine and Toxicology 04/2010; 5:8. · 1.23 Impact Factor
  • Pneumologie 03/2010; 64.
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    ABSTRACT: DNA methylation is an important epigenetic mechanism involved in fundamental biological processes such as development, imprinting, and carcino-genesis. For these reasons, DNA methylation represents a valuable source for cancer biomarkers. Methods for the sensitive and specific detection of methylated DNA are a prerequisite for the implementation of DNA biomarkers into clinical routine when early detection based on the analysis of body fluids is desired. Here, a novel technique is presented for the detection of DNA methylation biomarkers, based on real-time PCR of bisulfite-treated template with enzymatic digestion of background DNA during amplification using the heat-stable enzyme Tsp509I. An assay for the lung cancer methylation biomarker BARHL2 was used to show clinical and analytical performance of the method in comparison with methylation-specific PCR technology. Both technologies showed comparable performance when analyzing technical DNA mixtures and bronchial lavage samples from 75 patients suspected of having lung cancer. The results demonstrate that the approach is useful for sensitive and specific detection of a few copies of methylated DNA in samples with a high background of unmethylated DNA, such as in clinical samples from body fluids.
    BioTechniques 09/2009; 47(3):737-44. · 2.40 Impact Factor
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    ABSTRACT: Interstitial lung disease (ILD) is a frequent manifestation of systemic sclerosis (SSc), and cytokines can contribute to the disease pathology. The aim of the current study was to identify specific changes in cytokine levels that may serve as disease markers and possible targets for therapy. Cytokines were measured with bioplex analysis in 38 bronchoalveolar fluids (BALFs) from 32 SSc patients (27 with alveolitis and 11 without alveolitis) and 26 control patients. In the case of SSc patients, cytokines were correlated with the respective bronchoalveolar lavage (BAL) cell differentiation, lung function, and thoracic HR-CT score. For 35 BALF samples derived from 29 SSc patients, follow-up investigations of clinical data, lung-function parameter, or thoracic HR-CT scans were available to evaluate the predictive capacity of BALF cytokines and chemokines. High IL-7 levels were characteristic of SSc-associated interstitial lung disease (ILD) and, in addition, when compared with ILD-negative SSc patients, ILD-positive SSc patients revealed higher IL-4, IL-6, IL-8, and CCL2 (MCP-1) BALF levels. High CCL2 and IL-8 BALF concentrations were associated with neutrophilic and mixed alveolitis. Cytokine levels of IL-4, IL-8, and CCL2 correlated negatively with lung-function parameters; CCL2 concentrations also correlated with HR-CT scores. High concentrations of several cytokines were associated with the progress of ILD and end-stage ILD. Univariate analyses revealed high IL-2 and tumor necrosis factor-alpha (TNF-alpha) levels as the best predictors for progressive disease, together with lung-function parameters, young age, and neutrophilic alveolitis. Multivariate analyses partially confirmed these results but did not sufficiently converge because of the limited number of patients. The association of BALF cytokines with lung fibrosis and its progress suggests that cytokines contribute to the pathogenesis of ILD and hence could be regarded as potential therapeutic targets.
    Arthritis research & therapy 08/2009; 11(4):R111. · 4.12 Impact Factor
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    ABSTRACT: Matrix metalloproteinases (MMPs) and cathepsins have been implicated in the pathogenesis of several interstitial lung diseases by their effects on inflammatory processes and extracellular matrix remodelling. The aim of this study was to investigate whether macrophage-derived MMPs and cathepsins are involved in the pathogenesis of sarcoidosis. Therefore the release of MMP-2, MMP-9, and cathepsins B and L from alveolar macrophages (AM) in active pulmonary sarcoidosis was studied and compared to normal controls and patients with pneumonia and fibrosis. Patients with sarcoidosis (n = 11), pulmonary fibrosis (n = 7), and pneumonia (n = 9) and normal controls (n = 10) were enrolled in the study. AM were obtained by bronchoalveolar lavage and cultured without stimulation and in presence of tumor necrosis factor alpha (TNFalpha) and interleukin-10 (IL-10). The release of cathepsins and MMPs as well as IL-10 and TNFalpha was measured in the supernatant of cultured AM by fluorimetric assays and zymography. AM of patients with sarcoidosis and pneumonia spontaneously released more MMP-2 than normal controls. Stimulation with TNFalpha showed no effects on MMP-2 and MMP-9 production. Exogenous IL-10 led partially to an inhibition of the MMP-2 and MMP-9 release. Patients with sarcoidosis produced significantly more IL-10 and TNFalpha than normal controls. This was not observed in patients with fibrosis and pneumonia. The spontaneous release of cathepsins B and L did not differ between the patient groups and normal controls and was not affected by TNFalpha and IL-10. The data show that AM of patients with sarcoidosis and pneumonia release significant amounts of MMP-2. The endogenous production of IL-10 in AM of patients with sarcoidosis and the MMP downregulation by exogenous IL-10 suggest an involvement of IL-10 in MMP regulation. Furthermore the results suggest that the production of MMP-2 is more specific for acute lung injury, rather than for a single lung disease such as sarcoidosis.
    Experimental Lung Research 07/2009; 28(1):55-68. · 1.75 Impact Factor
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    ABSTRACT: First-generation adenoviral (Ad) vectors are frequently used vectors for experimental and clinical gene transfer. Earlier it has been shown that parallel overexpression of the cell cycle regulator p21(Waf1/Cip1) (p21) or antiapoptotic bcl-2 from a second vector reduces cytotoxicity and improves transgene expression. Here, we investigate whether the co-expression of p21 and alpha(1)-antitrypsin from a single vector improves vector safety and alpha(1)-antitrypsin expression. Cell lines (A549 and HeLa) and primary cells (small airway epithelial cells and hepatocytes) were infected with adenovirus vectors transducing alpha(1)-antitrypsin with (AdCMV.p21-RSV.hAAT) or without (AdRSV.hAAT) p21. alpha(1)-Antitrypsin expression and cytotoxicity were analyzed using western blot/ELISA and LDH/ALT/AST assays, respectively. Cell cycle profiles were determined by flow cytometry. Co-expression of p21 strongly increased the alpha(1)-antitrypsin expression in all cell types and at all doses tested. No changes in ALT/AST from hepatocytes and only minor increases in the LDH release in A549 and HeLa were observed with either vector. Cell cycle profiles were also not affected adversely. Incorporation of p21 in Ad vectors together with a gene of interest improves the vector performance; such vectors will allow the application of lower doses and thereby reduce immunological side effects.
    Gene therapy 03/2009; 16(4):574-8. · 4.75 Impact Factor
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    ABSTRACT: In SSc, diagnosis and classification is based mainly on skin sclerosis. Herein, we investigated in a large multicentre cohort, to what extent skin sclerosis reflects organ involvement and additional clinical symptoms. A total of 1200 SSc patients from the register of the German Systemic Sclerosis Network (DNSS), classified as either lcSSc or dcSSc, were analysed for their serological characteristics, clinical symptoms and organ manifestations in relation to skin involvement measured by the modified Rodnan skin score (mRSS). SSc patients with different mRSS did not differ significantly in their disease duration and in most of the clinical symptoms. They showed a similar distribution of most organ manifestations such as pulmonary arterial hypertension as well as cardiac, renal and nervous system involvement. More severe skin thickening was found to be associated with pulmonary fibrosis and gastrointestinal symptoms, as well as with digital ulcers and musculoskeletal involvement. In patients with SSc, potentially life-threatening complications and clinical symptoms with high impact on the quality of life occur independently from the extent of skin sclerosis. The diagnosis in SSc patients with a low mRSS could be missed or they could be insufficiently treated.
    Rheumatology (Oxford, England) 02/2009; 48(1):70-3. · 4.44 Impact Factor
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    ABSTRACT: In several papers an increased quantity of cell-free plasma DNA as well as the presence of long DNA fragments in cell-free plasma and serum has been described. We isolated cell-free DNA from plasma, serum, and bronchial lavage supernatants from 33 lung cancer patients and 27 patients with a benign lung disease. The DNA was amplified by real-time PCR, and the quantity as well as the DNA integrity was determined. We did not find significant differences between the patient populations. Our results led us to conclude that this method is not useful in a diagnostic setting and is not able to differentiate between lung cancer patients and patients with a benign lung disease.
    Annals of the New York Academy of Sciences 09/2008; 1137:207-13. · 4.38 Impact Factor
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    ABSTRACT: Pulmonary arterial hypertension (PAH) is a progressive disease, with right-heart failure being the main cause of death. In patients refractory to conventional drug therapy, atrial septostomy can serve as palliative treatment or as a bridge to transplantation. A 41-year-old woman with a 15-year history of PAH associated with a corrected atrial septal defect presented with severe deterioration of symptoms. Echocardiography confirmed reocclusion of an atrial septal stoma that had been created several months before. After performing a repeat atrial septostomy, we implanted a custom-made atrial septostomy device, an Amplatzer septal occluder that had been fenestrated to serve as a custom-made atrial septostomy device. This resulted in an improvement in cardiac output and a marked symptomatic relief. During the 6-year follow-up, the patient was clinically stable with limited but constant exercise tolerance, under specific medical therapy. Repeated echocardiography confirmed long-term patency of the device.
    Chest 02/2008; 133(1):283-5. · 7.13 Impact Factor
  • Pneumologie 01/2008; 62.
  • Pneumologie 01/2008; 62.
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    ABSTRACT: In patients with chronic obstructive pulmonary disease (COPD) weight loss frequently occurs that may ultimately lead to cachexia as a serious co-morbidity, indicating severely impaired functional capacity, health status and increased mortality. Increased energy expenditure due to mechanic and metabolic inefficiency and systemic inflammation are determinants of a hypermetabolic state that is not balanced by dietary intake. Anorexia may importantly contribute to weight loss in COPD, however, the association between immune and hormonal derangement and altered appetite has not been studied in detail. The aim of the present study was to investigate whether anorexia in COPD is related to inflammation and hormonal derangement in association to weight loss. We prospectively enrolled 103 consecutive patients with COPD (age 59.8+/-1.3 years, 35% female, mean FEV1 38.3+/-1.7%) in comparison to healthy controls of similar age (n=15). In 34 patients (33%) cachexia was diagnosed (weight loss >7.5%, BMI < or = 24 kg/m2). Cachectic COPD patients had lower BMI (19.0+/-0.5 vs 25.6+/-0.7 kg/m2) and impaired lung function (FEV1 31+/-2% vs 42+/-2%, FVC 51+/-3 vs 59+/-3%, both p<0.001). Inflammatory immune activation (IL-6 and IL-6/IL-10 ratio) was significantly higher in cachectic COPD patients. Analysis of the extent of anorexia (visual analogue scale) revealed that cachectic COPD patients had significantly decreased subjective desire to eat compared to non-cachectic patients (3.5+/-0.3 vs 6.3+/-0.2, p<0.001). Patients with COPD and cachexia showed evidence of acquired GH resistance (decreased IGF-1/GH ratio) and insulin resistance (HOMA). Anorexia showed a direct correlation with the IGF-1/GH ratio (r=0.34, p<0.05) and was further related to BMI and % weight loss (both p<0.001). In COPD anorexia relates to hormonal derangement and inflammatory immune activation. Anorexia contributes to development of cachexia. The concept of appetite stimulating therapy emerges as a novel therapeutic option in cachectic COPD patients.
    International journal of cardiology 06/2007; 119(1):83-9. · 6.18 Impact Factor
  • Pneumologie 01/2007; 61.
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    ABSTRACT: The optimal approach to initiate positive-pressure therapy in patients with obstructive sleep apnea is still debated. Current options are autotitrating positive airway pressure (APAP) or manual titration with continuous positive airway pressure (CPAP). Procedures differ by parameters and by algorithms used for adapting pressure. To evaluate the efficacy of attended automatic titration in a randomized crossover study compared with manual titration over 2 nights where the sequence of the titration mode was changed. Therapy outcome was controlled after 6 weeks. 21 sleep apnea patients were treated using manual CPAP versus automatic APAP titration. The mode used during the 2nd night was continued for 6 weeks. Cardiorespiratory polysomnography, Epworth Sleepiness Scale (ESS), SF-36 score and compliance were assessed. Apnea-hypopnea index reduction was equally effective at similar effective pressure independent of the titration mode. If APAP was applied during the 1st night, total sleep time was longer (384 vs. 331 min, p < 0.01) and sleep efficacy was higher (91 vs. 81%, p < 0.01) than after starting with manual titration with CPAP. Compliance was comparable in both groups (4.6 +/- 1.9 h). The ESS improved in both groups (from 12.9 to 6.5). SF-36 scores and therapeutic pressure did not much change. Taking the sequence of titration into account, we found equal effectiveness of CPAP and APAP. Sleep quality was better with initial application of APAP - which favors attended automatic titration if only 1 titration night is possible. Both modes are comparable after 6 weeks regarding therapeutic pressure, efficacy, compliance and quality of life.
    Respiration 01/2007; 74(3):279-86. · 2.92 Impact Factor
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    ABSTRACT: Chronic obstructive pulmonary disease (COPD) is a multisystemic inflammatory disease characterized by pulmonary and extrapulmonary symptoms. The impaired lung function has long-term implications on metabolism and homeostasis of many organ systems such as the skeleton, heart, brain and skeletal muscle. The occurrence and prevalence of anemia in COPD has rarely been studied. Anemia is such a common and simple clinical finding that we may underestimate its physiological relevance in COPD. The aim of the study was to retrospectively investigate the prevalence of anemia in a large population of COPD patients and to compare it to patients with chronic heart failure, renal insufficiency, cancer and asthma. A population of 7337 patients that was treated in the University Hospital Charité, Berlin, Germany, from 1996 to 2003 was subsetted according to the ICD-9/10 code of the discharge diagnoses into the above-mentioned diagnoses groups. The overall prevalence of anemia in COPD patients was 23.1%. It was comparable to the prevalence of anemia we found in patients with chronic heart failure (23.3%). Patients with renal insufficiency and cancer presented the highest anemia frequencies. The high prevalence of anemia in hospitalised COPD patients that were treated mostly for exacerbations gives evidence that anemia is also a comorbidity in COPD and may contribute to exercise limitation and dyspnoea.
    International Journal of Cardiology 09/2006; 111(3):365-70. · 6.18 Impact Factor
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    ABSTRACT: Two-dimensional strain echocardiography is a new method for the assessment of regional contractility. Thirty-seven patients with pulmonary arterial hypertension (mean age 56.4 +/- 11 years) and 38 normal subjects (mean age 58.3 +/- 12 years) underwent 2-dimensional echocardiography and tissue Doppler echocardiographic evaluation of right ventricular (RV) global function and regional contractility. Patients with pulmonary arterial hypertension additionally underwent 6-minute walking distance tests and right-sided cardiac catheterization before and after (8 +/- 3 months) vasodilator therapy. Moderate or severe RV dysfunction was present in all patients (2-dimensional strain of the basal segment of the RV free wall: -8.8 +/- 4.1% systolic longitudinal deformation) compared with normal subjects (-24.3 +/- 4.7% systolic longitudinal deformation, p < 0.001) and was improved with vasodilator therapy after 6 to 11 months (-13.3 +/- 6.2% systolic longitudinal deformation, p < 0.001).
    The American Journal of Cardiology 09/2006; 98(4):530-4. · 3.43 Impact Factor
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    B Schmidt, C Witt
    Pneumologie 02/2006; 60(1):45-9.

Publication Stats

2k Citations
358.73 Total Impact Points


  • 1999–2007
    • Charité Universitätsmedizin Berlin
      • • Interdisciplinary Center of Sleep Medicine
      • • Department of Cardiology and Pulmonology
      • • Institute of General Medicine
      Berlin, Land Berlin, Germany
  • 2005
    • Freie Universität Berlin
      Berlín, Berlin, Germany
    • Hannover Medical School
      • Centre for Internal Medicine
      Hannover, Lower Saxony, Germany
  • 1990–2005
    • Humboldt-Universität zu Berlin
      • • Clinical Psychology Research Unit
      • • Department of Biology
      Berlín, Berlin, Germany
  • 2004
    • Humboldt State University
      Arcata, California, United States
  • 2002–2004
    • The University of Edinburgh
      Edinburgh, Scotland, United Kingdom
    • University of Leipzig
      Leipzig, Saxony, Germany
  • 2003
    • Max Planck Institute of Colloids and Interfaces
      Potsdam, Brandenburg, Germany
  • 2002–2003
    • University of Freiburg
      Freiburg, Baden-Württemberg, Germany
  • 1997
    • Deutsches Herzzentrum Berlin
      • Cardiothoracic and Vascular Surgery
      Berlín, Berlin, Germany