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Claus Vogelmeier

Publications and source records attributed to Claus Vogelmeier.

23 records · Page 2Linked to original sources
PubMed2003

Dynamics of heart rate and sleep stages in normals and patients with sleep apnea.

Sleep is not just the absence of wakefulness but a regulated process with an important restorative function. Based on electroencephalographic recordings and characteristic patterns and waveforms we can distinguish wakefulness and five sleep stages grouped into light sleep, deep sleep, and rapid-eye-movement (REM) sleep. In order to explore the functions of sleep and sleep stages, we investigated the dynamics of sleep stages over the night and of heart-rate variability during the different sleep stages. Sleep stages and intermediate wake states have different distributions of their duration and this allows us to create a model for the temporal sequence of sleep stages and wake states. Heart rate is easily accessed with a high precision by the recording and analysis of the electrocardiogram (ECG). Heart-rate regulation is part of the autonomous nervous system and sympathetic tone is strongly influenced by the sleep stages.

Heart Rate↗
PubMed2003

Association of right ventricular dysfunction and Cheyne-Stokes respiration in patients with chronic heart failure.

Cheyne-Stokes respiration (CSR) is present in up to 40% of patients with congestive heart failure (CHF) and is an independent risk factor for increased overall mortality. We examined whether CSR is associated with right ventricular (RV) dysfunction in CHF patients. Parameters of RV function were assessed by two-dimensional echocardiography and tissue velocity imaging in 42 patients (aged 23-75 years) with a left ventricular (LV) ejection fraction below 40%. Respiratory polygraphy revealed CSR with an central apnea-hypopnea index (CAHI) >10 h-1 in 13 of the 42 patients (31%). Demographic characteristics did not differ among the patient groups. The velocity of the tricuspid annular systolic motion (TASM), a parameter reflecting systolic RV function, was significantly reduced in CHF patients with CSR (10.5 +/- 2.3 cm s-1) compared with those without CSR (15.0 +/- 5.1 cm s-1, P = 0.004), and was inversely associated with the CAHI (y = 15.2-0.2x; r = 0.46, P = 0.003). The RV dimensions were significantly increased and the fractional RV area changes significantly reduced in CHF patients with CSR (33 +/- 17 versus 48 +/- 20%; P = 0.04). Doppler parameters of pulmonary artery flow indicate higher pulmonary artery pressures in CSR patients compared with patients without CSR, which is also reflected by an increased RV free-wall thickness in CSR patients (6.5 +/- 1.1 vs. 5.3 +/- 1.3 mm; P = 0.05). Parameters of systolic LV function, forced expiratory volume in 1 s (FEV1), and PaO2 and PaCO2 were not different among patients with or without CSR. In conclusion, CSR is associated with depressed systolic RV function and increased RV dimensions in CHF patients. Future studies will show whether optimized treatment of CSR will improve RV function.

Adult↗
PubMed2003

An angiogenic role for the human peptide antibiotic LL-37/hCAP-18.

Antimicrobial peptides are effector molecules of the innate immune system and contribute to host defense and regulation of inflammation. The human cathelicidin antimicrobial peptide LL-37/hCAP-18 is expressed in leukocytes and epithelial cells and secreted into wound and airway surface fluid. Here we show that LL-37 induces angiogenesis mediated by formyl peptide receptor-like 1 expressed on endothelial cells. Application of LL-37 resulted in neovascularization in the chorioallantoic membrane assay and in a rabbit model of hind-limb ischemia. The peptide directly activates endothelial cells, resulting in increased proliferation and formation of vessel-like structures in cultivated endothelial cells. Decreased vascularization during wound repair in mice deficient for CRAMP, the murine homologue of LL-37/hCAP-18, shows that cathelicidin-mediated angiogenesis is important for cutaneous wound neovascularization in vivo. Taken together, these findings demonstrate that LL-37/hCAP-18 is a multifunctional antimicrobial peptide with a central role in innate immunity by linking host defense and inflammation with angiogenesis and arteriogenesis.

Acetylcysteine↗
PubMedDate not supplied

Exposure of differentiated airway epithelial cells to volatile smoke in vitro.

BACKGROUND: Cigarette smoke (CS) is the predominant pathogenetic factor in the development of chronic bronchitis and chronic obstructive pulmonary disease. The knowledge about the cellular and molecular mechanisms underlying the smoke-induced inflammation in epithelial cells is limited. OBJECTIVES: The aim of this study was to develop an in vitro model to monitor the effects of volatile CS on differentiated airway epithelial cells. METHODS: The airway epithelial cell line MM-39 and primary human bronchial epithelial cells were cultivated as air-liquid interface cultures and exposed directly to volatile CS. We used two types of exposure models, one using ambient air, the other using humidified and warm air. Cytokine levels were measured by quantitative PCR and ELISA. Phosphorylation of p38 MAP kinase was assessed by Western blot analysis. To reduce the smoke-induced inflammation, antisense oligonucleotides directed against the p65 subunit of NF-kappaB were applied. RESULTS: Exposure of epithelia to cold and dry air resulted in a significant inflammatory response. In contrast, exposure to humidified warm air did not elicit a cellular response. Stimulation with CS resulted in upregulation of mRNA for IL-6 and IL-8 and protein release. Exposure to CS combined with heat-inactivated bacteria synergistically increased levels of the cytokines. Reactions of differentiated epithelial cells to smoke are mediated by the MAP kinase p38 and the transcription factor NF-kappaB. CONCLUSIONS: We developed an exposure model to examine the consequences of direct exposure of differentiated airway epithelial cells to volatile CS. The model enables to measure the cellular reactions to smoke exposure and to determine the outcome of therapeutic interventions.

Atmosphere Exposure Chambers↗