Search PubMed⌕ Search

Biomedical subjects

Wolfgang Domej

Publications and source records attributed to Wolfgang Domej.

17 recordsLinked to original sources
PubMed2005

Effects of a fast cable car ascent to an altitude of 2700 meters on EEG and ECG.

In the Eastern Alps, the Dachstein massif with a height of almost 3000 m is an ideal location for investigating the effects of changes in altitude on the human body. Within a few minutes, a cable car facilitates an ascent from 1702 to 2700 m above sea level, where the partial pressure of oxygen is about 550 mmHg (as compared to 760 mmHg at sea level). In this study, 10 healthy subjects performed a reaction time task at 990 m and 2700 m in altitude. The subjects were instructed to perform a right hand index finger movement as fast as possible after a green light flashed (repeated 50 times). The corresponding electrocardiogram (ECG) and the electroencephalogram (EEG) were recorded. From the ECG heart rate and heart rate variability measures in the time and frequency domain were calculated. An event-related desynchronization/synchronization (ERD/ERS) analysis was performed with the EEG data. Finally, the EEG activity and the ECG parameters were correlated. The study showed that with the fast ascent to 2700 m the heart rate increased and the heart rate variability measures decreased. The correlation analysis indicated a close relationship between the EEG activity and the heart rate and heart rate variability. Furthermore it was shown for the first time that the beta ERS in the 14-18 Hz frequency range (post-movement beta ERS) was significantly reduced at high altitude. Very interesting also is the loss of correlation between EEG activity and cardiovascular measures during finger movement at high altitude. The suppressed post-movement beta ERS at the altitude of 2700 m may be interpreted as results of an increased cortical excitability level when compared with the reference altitude at 990 m above sea level.

Adult↗
PubMed2005

Effects of cable car ascent to 2700 meters on mean EEG frequency and event-related desynchronization (ERD).

In the Eastern Alps, the Dachstein massif with a height of almost 3000 m is an ideal location for investigating the effects of changes in altitude on the human body. A cable car allows an ascent within a few minutes to 2700 m, where the partial pressure of oxygen is about 550 mm of mercury compared to 760 mm at sea level. Ten healthy subjects performed a reaction time task at an altitude of 990 m and 2700 m. The subjects were instructed to perform a right hand index finger movement as fast as possible after a green light had flashed. The green light flashed 50 times. Simultaneously to the task, the electroencephalogram (EEG) was recorded. The event-related desynchronization (ERD) analysis of the EEG data showed that changes in alpha ERD values are not significant, but event-related synchronization (ERS) values in the beta band decrease significantly from around 50 % to 10 %. Furthermore, the mean frequency of the beta band increased from 16.68 Hz to 16.81 Hz (p = 0.0019) with the ascent. The suppressed post-movement beta ERS at an altitude of 2700 m may therefore be interpreted as a result of an increased cortical excitability level when compared with the reference altitude of 990 m above sea level.

Adult↗
PubMed2005

[Aspects and necessity of moderate-altitude research].

Alpinism in all its variations is a leading factor in tourism. Within a few decades, alpine sports, even at high altitudes, have become available to a wide range of people. Now, more people than ever before are hiking, trekking, climbing and skiing at moderate and high altitudes. Annually, 40 million people spend time in the Alps and 100 million visit high altitudes worldwide. However, alpine excursions may entail health problems and many aspects of impaired adaptation to altitude remain unstudied. High-altitude research has mainly been associated with expeditions, with moderate altitudes receiving far less attention, though most tourism takes place at that level. The overwhelming numbers of alpine tourists mean that there is urgent need for high- and moderate-altitude medical research, which would also be within the realm of political responsibility in mountainous countries. Research in mountain medicine and dissemination of relevant findings can show how to improve and conserve performance in healthy individuals and could point the way toward new, safe approaches in the rehabilitation of patients with chronic diseases. It is imperative that mountain medicine continues to develop on a scientific basis.

Academies and Institutes↗
PubMed2005

[Performance testing in mountaineering].

Laboratory ergometry to exhaustion allows cardiopulmonal risk assessment for the prevention of health problems related to mountaineering. Moreover, exercise testing evaluates functional status, so permitting individualized training programs and evaluation of training effects. Additionally, mountaineering-specific performance diagnosis allows individual as well as group-specific determination of exercise performance related to field conditions. Laboratory tests are standardized, easy to perform and cost effective. Treadmill ergometry with constant walking speed and increasing inclination is suggested to be predictive for mountaineering performance. On the other hand, the validity for the specific conditions for mountaineering is questionable. Standardized laboratory exercise tests combined with sport-specific exercise tests provide rough information on the ability to sustain real-situation strain. To compare individual exercise performance, published data tables obtained from field tests may be used. It must, however, be mentioned that high-altitude-adaptation is independent of exercise performance evaluated separately.

Acclimatization↗
PubMed2005

Oxidative stress caused by acute and chronic exposition to altitude.

In this article, current views on cellular and molecular biology (biochemical) mechanisms are discussed under the aspect of altitude exposition. The Andean, Tibetan, and Ethiopian patterns of adaptation to high-altitude hypoxia are known [Beal et al. (2002) Proc Natl Acad Sci USA 99: 17215-17218]. The phylogenetic tree of the human species suggests that there are genetic differences in adaptation patterns to chronic hypoxic hypoxia. Five defense mechanisms are well established for lowlanders who are exposed to acute hypoxic hypoxia. Consequences of the cellular decrease in ATP are the formation of hypoxanthine and xanthine, which are the substrates for the massive formation of superoxide anion radicals and hydrogen peroxide via the oxidase activity of the xanthine oxidoreductase reaction. Under severe hypoxia, about 51 % of the total inhaled oxygen is used to form superoxide anion radicals in rat liver [Gerber et al. (1989) Adv Exp Med Biol 253B, Plenum Press, New York, 497-504]. The reactivity and selectivity of the superoxide anion radical are modified by specific interactions and electron exchange. It is commonly accepted that the superoxide anion radical in aqueous solutions has a lifetime in the millisecond range. However, electron spin resonance spectroscopy studies in a KO2/H2O/iron ion system revealed for the first time a stabilization of a part of the initially added superoxide anion radicals lasting up to hours at room temperature [Földes-Papp (1992) Gen Physiol Biophys 11: 3-38]. Superoxide anion radicals adsorbed on an oxidic iron hydrate phase in aqueous systems might function as a strong oxidant similar to that species which has been suggested to be a complex between oxygen and different valence states of iron in the initiation of lipid peroxidation by ferrous iron. There were serious doubts about the identity of alkoxy radicals. For the first time, alkoxy radicals were directly demonstrated in solution by electron spin resonance spectroscopy [Földes-Papp et al. (1991) Adv Synth Catal 333: 293-301]. The redox status in mammalian cells is mainly determined by the antioxidant glutathione, which is a key player in maintaining the intracellular redox equilibrium and in the metabolic regulation of the cellular defense against oxidative stress. As reactive oxygen species occupy an essential role in membrane damage, the idea of membrane-bound enzymatic defense mechanisms gets a new dimension [Földes-Papp et al. (1981) Acta Biol Med Ger 40: 1129-1132; Földes-Papp and Maretzki (1982) Acta Biol Med Ger 41: 1003-1008]. The steady-state between antioxidants and pro-oxidants affects the gene expression via hypoxia-induced transcription activities. The transcription factor hypoxia-inducible factor 1 (HIF-1) is a global regulator of oxygen homeostasis. As discussed in this article, hypoxia or 'oxidative stress' is accompanied by appropriate molecular adaptation mechanisms at the enzymatic or epigenetic level (enzymatic and non-enzymatic radical inhibitors, posttranslational modifications) and at the genetic level (transcription, translation).

Adaptation, Physiological↗
PubMed2004

Clinical applicability of mass spectrometry for inhaled carbon compounds and the characterization of trace element patterns in body fluids.

So far, chemists, molecular biologists and biochemists have reaped the greatest benefits from mass spectrometry (Aebersold et al., 2003). This type of analysis could, however, be useful in many fields. Mass spectrometry is on its way to the doctor's office (Pusch et al., 2003; Földes-Papp et al., 2002; Henry 1999). The article is focused on laser-activated microprobe mass analysis (LAMMA) and inductively coupled argon plasma mass spectrometry (ICP-MS). Potential applications of the two types of mass spectrometry are demonstrated in clinical medicine. It is the first comprehensive review on qualitative characterization of carbonaceous compounds in lung tissue samples in situ and quantitative trace element determination in body fluids.

Aged↗
PubMed2003

[Are new antibiotics in therapy of respiratory tract infections necessary?].

Increasing worldwide antibacterial resistance among respiratory pathogens, especially S. pneumoniae, are an emerging problem in the treatment of respiratory tract infections. In some areas penicillin-resistant S. pneumoniae increased to 80% and macrolide-resistance and MLSb-resistance are an evolving problem. In addition, increasing resistance to quinolones has been documented in Hong Kong and in Spain. One way to combat increasing resistance is the development of new antimicrobial drugs. However, the practice of just changing one drug for another without also altering poor prescribing habits merely results in different resistance issues. In the long-term, to prevent increasing resistance, clinicians must be aware of restrictive antibiotic prescription and adequate dosages.

Anti-Bacterial Agents↗
PubMed2003

[From pneumonic infiltration to parapneumonic effusion--from effusion to pleural empyema: internal medicine aspects of parapneumonic effusion development and pleural empyema].

Infectious processes cause the majority part of all clinically relevant pleural effusions which frequently complicate the course of pneumonia. The assessment of an inflammatory effusion requires a careful history, physical examination, imaging techniques and clinical workup. The presence of polymorphonuclear leukocytes, high LDH-activity (> 200 U/L) and protein level (> 3 g/dL) in a pleural effusion indicates acute inflammation. An effusion is usually called empyema, when large numbers of neutrophils form thick, turbid exudates within preexisting body cavities. A thoracic empyema may occur as a result of primary or secondary pleural pathologies and in most cases involves infection with bacteria, frequently provided by progressing pneumonia. There are several therapeutic options for treatment of parapneumonic effusions and of thoracic empyemata, respectively. Optimal therapeutic management and antimicrobial medication to the infected pleural space depend in part on the stage of the empyema at presentation. Treatment can vary from a conservative medical approach in uncomplicated or small parapneumonic effusions to invasive surgical interventions in fibroprulent or organizational stages of empyema. Empyemata usually progress from a parapneumonic exudative stage (stage I), when the fluid is still sterile, with low leukocyte counts, low LDH, physiological pH, and normal glucose, to the fibropurulent [figures: see text] stage (stage II) with high leukocyte counts, high LDH activity, low pH, and low glucose, and finally to the organizational stage (stage III), in which fibroblasts convert fibrin strands into inelastic membranes. Pleural peels and pockets may compartmentalize the viscous empyematous fluid and can cause serious restrictive ventilatory impairment. Each patient must be individually evaluated to determine the nature of the exudate and the stage of the pleural space infection. Due to its high mortality rate (5%) a thoracic empyema requires prompt treatment. Diagnostic thoracentesis and withdrawal of liquid for the microbiological, cytological and biochemical analysis is urgently recommended in all cases to assess severity of the disease and the likelihood of a complicated or uncomplicated course, and to select the most appropriate treatment option.

Anti-Bacterial Agents↗
PubMed2003

Reconstructed mass-spectrometric pattern for characterization of carbon compounds in smoker's lung in situ.

BACKGROUND: Cigarette smoke is a major anthropogenic pollutant and contributes to the permanent load of ambient particulate matter in the air, particularly indoors. It is the leading risk factor for premature loss of life due to chronic bronchitis, emphysema and lung cancer. Smoker's lung and graphite pneumoconiosis are pathological states characterized by the deposition of carbonaceous particles. METHODS: Mass spectrometry was used to evaluate unstained lung sections obtained in vivo from a heavy smoker and a patient with occupationally acquired graphite pneumoconiosis. RESULTS AND DISCUSSION: The composition of carbon compounds deposited in lung tissue samples is demonstrated here for the first time. Thirty carbonaceous-containing microareas from ten biopsies (three areas per biopsy) of lung tissues were analyzed mass-spectrometrically. In each case, the samples were taken from a smoker's lung or those demonstrating a graphite pneumoconiosis. The lung-tissue samples were selected by light microscopy before they were evaporated for mass spectrometry. First-order criteria were anionic and cationic mass peaks which occur within the mass patterns in lung tissues of smoker's lung, although not in graphite pneumoconiosis. Second-order criteria were mass peaks from smoker's lung with standard deviations SD < or = 14% of the mean value. First and second-order mass peaks matched the mass peaks of experimental cigarette-smoke condensate in 9 out of 11 peaks. A software program was developed that enabled fast, automated recognition of the typical mass peaks, and thereby confirmed the histological diagnosis of smoker's lung. CONCLUSIONS: The analysis of carbonaceous particles within lung biopsies from a heavy smoker corresponded to the spectra of tobacco condensate and not to the investigated biopsies of graphite peneumoconiosis. RECOMMENDATION AND OUTLOOK: The analyses were performed in order to find out whether mass-spectrometric criteria exist for the differentiation of carbonaceous lung-tissue deposits. Mass spectrometry may be a valuable tool in determining the composition of carbon compounds deposited in human lung tissue. So far, qualitative assessment of the composition of deposits in lung tissue is only possible after the patient is deceased (autopsy).

Aged↗
PubMed2002

Detection of graphite using laser microprobe mass analysis of a transbronchial biopsy from a foundry worker with mixed dust pneumoconiosis.

Inhalation of dust containing graphite can cause lung disease in foundry workers and workers in graphite mines or mills. Mixed dust pneumoconiosis caused by long-term occupational exposure to graphite dust is a rare disease. Only a few cases of graphite pneumoconiosis have been reported in literature, and these were usually diagnosed post mortem. Our report is of an 80-year-old male patient who had worked in an iron foundry for 20 years and whose work had entailed regular contact with ground graphite and foundry vapors. Chest x-rays revealed both a reticular and nodular pattern in the lung, moderate apical distractions and pleural scarring, all of which were confirmed by high-resolution computed tomography. Bronchoalveolar lavage and transbronchial biopsies were also consistent with mixed dust pneumoconiosis, and due to the long-term dust exposure, graphite pneumoconiosis was strongly suspected. To confirm this diagnosis, the chemical composition of the dark granules in the semi-thin histological sections of the transbronchial biopsies were analyzed using laser microprobe mass spectroscopy. The mass spectra of these black particles were consistent with those of natural graphite powder. Comparative analyses of normal lung tissue did not produce similar spectral patterns. We conclude that histology and cytology does not always suffice to confirm a diagnosis of graphite pneumoconiosis, because black particles are also found in conditions resulting from other exposures, such as heavy smoking or coal mining. Analysis of the composition of particles deposited in the lung tissue offers more precise information, which can be used as evidence in occupational and forensic medicine. Laser microprobe mass spectroscopy can assess the mineral dust load in lung samples.

Aged↗
PubMed2002

Tissue transglutaminase antibody determination in celiac disease. Analysis of diagnostic specificity of anti-human IgA-type assays.

Biopsy is onerous and, for this reason, immunodiagnostics in sera of celiac disease patients are an "additional diagnostic standard." The objective of the study was to investigate the variability in diagnostic specificity of ELISAs for the detection of IgA anti-tissue transglutaminase antibodies in serum of celiac disease patients who underwent biopsy. All patients were included in the study on the basis that they had a small intestinal biopsy. We studied 18 patients with histological proven celiac disease (7 male, 11 female, mean age +/- SD: 35+/-19 years) from Graz, Austria. Healthy control subjects were also entered into the study. The determinations of the anti-tissue transglutaminase antibodies were simultaneously performed together with the endomysium and gliadin antibody markers. We analysed the 216 serum values according to Cochran's non-parametric Q-test. The complexity to the analysis reflects the complexity of the diagnostic situation with the patients. No real differences were found in the reactions of the anti-human IgA-type anti-tissue transglutaminase ELISAs. Based on these results, an association was established between the outcomes of anti-human IgA-type ELISAs for the specific antigen and patients with histologically proven celiac disease, treated for celiac disease after histology was carried out and the diagnosis was made, and healthy controls. The detection of IgA anti-tissue transglutaminase antibodies in serum is a promising alternative to the indirect immunofluorescence determination of IgA-type endomysium antibodies. One ELISA for the specific antigen showed some advantage with respect to its extended scale of detection. Immunopathology of celiac disease can be based on the results of the appropriate IgA anti-tissue transglutaminase ELISAs under uncomplicated gastrointestinal conditions.

Antibodies, Monoclonal↗
PubMed2002

A new dimension for the development of fluorescence-based assays in solution: from physical principles of FCS detection to biological applications.

Ultrasensitive detection methods such as laser-induced fluorescence represent the current state-of-the-art in analytics. Single-molecule detection in solution has received a remarkable amount of attention in the last few years because of its applicability to life sciences. Studies have been performed on the fundamentals of the detection processes themselves and on some biological systems. Fluorescence correlation spectroscopy (FCS) is the link for ultrasensitive multicomponent analysis, showing possibilities for experiments on molecular interactions. Based on the theoretical background of FCS, this article gives full explanation of FCS and an update of highlights in experimental biology and medicine studied by FCS. We focus on a repertoire of diverse immunoglobulin specificities, a ribosome display system, single-molecule DNA sequencing, and a mutant enzyme generated by random mutagenesis of amino acids. We describe the usefulness and the enormous potential of the methodology. Further, this contribution clearly indicates that FCS is a valuable tool for solution-phase single-molecule (SPSM) experiments in immunobiology and medicine. In experiments with the Goodpasture autoantibody, we worked out conditions for the design of experiments on a complex single molecule in solution. The possibility to use SPSM-FCS as a quantitation methodology opens up other important applications beyond the scope of this article. Original results extending the published studies are presented for the rational foundation of SPSM-FCS. In this original contribution, we deal with experimental systems for biology and medicine where the number of molecules in solution is very small. This article is mandatory for gaining confidence in the interpretation of experimental SPSM-FCS results on the selfsame, individual single molecule in solution.

Autoantibodies↗
PubMed2002

Prolonged endurance challenge at moderate altitude: effect on serum eosinophil cationic protein, eosinophil dynamics, and lung function.

BACKGROUND: Eosinophils contain granule proteins such as eosinophil cationic protein (ECP) that have proinflammatory effects on airways. ECP may be released on activation of eosinophils into the plasma and is widely used as a marker of bronchial hyperreactivity and allergic inflammation. Environmental factors as well as intense physical exertion may influence eosinophil-related bronchial hyperreactivity. STUDY OBJECTIVES: To investigate the effect of endurance exercise at moderate altitude on levels of circulating eosinophils, serum ECP, serum osmolality (sOS), and dynamic pulmonary function parameters in healthy mountaineers. SETTING: Alpine field study performed in the Alps of Upper Styria in Austria. Type of exercise: Ascent of a mountain at maximal speed. PARTICIPANTS: Thirty healthy male volunteers from a troop of military mountaineers. RESULTS: Mean ECP concentration increased by 66% at the summit checkpoint (H2) and remained at 63% above baseline (base checkpoint [H0]) after descent (H4), while the blood eosinophil count decreased concomitantly from 250/microL at H0 (preexercise) to 118/microL (53%) at H2 and to 22/microL (81%) at H4. The total serum ECP concentration adjusted to sOS correlated negatively with blood eosinophil count (r = - 0.37; p < 0.0001) and PaO(2) (r = - 0.34; p < 0.001), but positively with the peak expiratory flow (PEF) [r = 0.45; p < 0.0001]. Although sOS correlated with serum ECP at H2 (r = 0.47; p = 0.02) and at 12 h after the start of the experiment (H12) [r = 0.57; p = 0.003], the relationship between total ECP and sOS (r = 0.19; p = 0.034) was less pronounced. FEV(1) in percentage of FVC (%FEV(1)/FVC) [the Tiffenau test], forced expiratory flow rate at 25% of vital capacity, and PEF were significantly higher at H2 than at H0 and H4. %FEV(1)/FVC decreased to 88% (p < 0.01) and 83% (p < 0.001) predicted at H12 and 24 h after start of the experiment, respectively. CONCLUSION: Results provide strong evidence for nonspecific activation of blood eosinophils during prolonged intense aerobic exercise at moderate altitude, modifying both eosinophil dynamics and regulation of ECP release in healthy subjects.

Adult↗
PubMed2002

Sequential thoracentesis: minor change of zinc compared to other selected essential trace elements in the serum.

This study first indicates that the serum trace element Zn tends to decrease in the course of sequential thoracenteses. Other selected essential elements such as copper (Cu), manganese (Mn), molybdenum (Mo), and cobalt (Co) do not reveal loss changes in their serum levels. Therefore, Zn should be monitored in patients who undergo repeated thoracentesis. To measure the magnitude of changes in serum trace elements and the clinical relevance of potential imbalances, concentrations of the essential elements are analyzed in 57 serum/effusion pairs obtained from 5 patients (4 male, 1 female; age 28-78 yr) who underwent repeated thoracenteses as a result of recurrent pleural effusion. All patients declined other therapeutic options such as chemical pleurodesis and/or chest tube placement. The total volumes of fluid removed ranged from 2.3 to 19.3 L and the frequency of thoracentesis ranged from 6 to 15 within a period of 102-174 days. Two patients had benign pleural disease and three had malignancies. Three patients suffered from pleural effusions resulting from exudates (total protein content > 3.0 g/dL, LDH > 200 U/L), and two resulting from transudates (total protein < 3.0 g/dL, LDH < 200 U/L). All trace elements were simultaneously determined by inductively coupled argon plasma-mass spectrometry. In addition, the concentrations of the following clinically relevant parameters were analyzed by standard methods: total protein, pH, leukocyte count, lactate dehydrogenase, and glucose.

Adult↗
PubMed2002

Cystatin C of pleural effusion as a novel diagnostic aid in pleural diseases of different aetiologies.

There has been considerable recent interest in the potential use of serum cystatin C as a diagnostic tool. Here we examined the hypothesis that the cystatin C level in the pleural effusion can differ from the corresponding serum level. We evacuated pleural effusion fluids from 47 patients by thoracentesis. Cystatin C, beta(2)-microglobulin, inorganic phosphate, creatinine and total protein were quantified in both pleural effusion fluids and corresponding sera. We determined cystatin C levels in pleural effusions and calculated the ratio of cystatin C levels in serum and effusion, to discriminate between effusions caused by severe renal impairment and other types of effusion. Extremely high concentrations of cystatin C in serum/effusion pairs were only measured in patients with renal failure (6.0 +/- 0.8/6.0 +/- 0.8 mg/l, means +/- S.D., n=11). A clearly defined region was found to correspond to pleural effusion caused by renal failure (r=0.954). The quantification of cystatin C in the effusion was justified by the discovery that there were some patients with a high serum cystatin C level but a low effusion concentration, or a low serum cystatin C but a high effusion concentration, indicating causes other than renal failure. In conclusion, the pilot data indicate a relationship between the cystatin C concentration in pleural fluid and the underlying disease. Thus cystatin C levels in pleural effusion and serum may be a valuable criterion for the differential diagnosis of pleural diseases of different aetiologies.

Aged↗