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Biomedical subjects

G Schueller

Publications and source records attributed to G Schueller.

6 recordsLinked to original sources
PubMed2006

Does marathon running cause acute lesions of the knee? Evaluation with magnetic resonance imaging.

An investigation was conducted into whether running a marathon causes acute alterations in menisci, cartilage, bone marrow, ligaments, or joint effusions, which could be evaluated by magnetic resonance imaging (MRI). Twenty-two non-professional marathon runners underwent MRI of the knee before and immediately after running a marathon. Lesions of menisci and cartilage (five-point scale), bone marrow, ligaments (three-point scale), joint effusion, and additional findings were evaluated and a total score was assessed. Before the marathon, grade 1 lesions of the menisci were found in eight runners, and grade 2 lesions in five runners. After the marathon, an upgrading from a meniscal lesion grade 1 to grade 2 was observed in one runner. Before the marathon, grade 1 cartilage lesions were found in three runners, and grade 2 lesions in one runner, all of which remained unchanged after the marathon. Before and after the marathon, unchanged bone marrow edema was present in three runners and unchanged anterior cruciate ligament lesions (grade 1) were seen in two runners. Joint effusions were present in 13 runners in the pre-run scans, slightly increased in four runners after the marathon, and newly occurred in one runner after the marathon. A total score comprising all knee lesions in each runner showed an increase after the marathon in two runners, whereas no runner showed an improvement of the radiological findings (Wilcoxon signed-rank test, P>0.05). The evaluation of lesions of the knee with MRI shows that marathon running does not cause severe, acute lesions of cartilage, ligaments, or bone marrow of the knee in well-trained runners. Only subtle changes, such as joint effusions or increased intrameniscal signal alterations, were imaged after running a marathon.

Acute Disease↗
PubMed2004

Bronchial reactivity in hyperresponsive patients and healthy individuals: demonstration with high resolution computed tomography.

OBJECTIVE: High resolution computed tomography (HRCT) was used to assess the extent of bronchial reactivity after inhalative bronchoprovocation and dilation in hyperresponsive patients and healthy subjects. PATIENTS AND METHODS: Patients with mild intermittent asthma, 15 with a >20% decrease in FEV1 and a >10 mmHg (PC20+) in PaO2, 12 with a <20% decrease in FEV1 and a >10 mmHg (PC20-) in PaO2 after provocation, and eight healthy humans were included in the study. Changes in cross-sectional area in a total of 1256 bronchi and in bronchial wall area (792 bronchi) were evaluated after histamine-triggered bronchoprovocation and salbutamol-induced bronchodilation at high lung volumes (FVC 80%). Data were compared with the results of pulmonary function tests (FEV1, PaO2, PaCO2). RESULTS: In all groups, a significant decrease in bronchial cross-sectional area (P<0.001) and a significant increase in bronchial wall area (P<0.001) were observed subsequent to bronchoprovocation. After bronchodilation, the increase in cross-sectional area (P<0.001) and the further increase in airway wall area (P<0.01) were significant in all groups. In PC20+ and PC20- asthmatics, significant differences (P<0.05) in PaO2, >10 mmHg between baseline and provocation were observed. In healthy persons, the PaO2 decrease was <10 mmHg (P>0.05). After histamine provocation, the decrease in FEV1 was measured in the PC20+ group, whereas a <20% FEV1 decrease was found in the PC20- and the control groups, respectively. No significant correlations were observed between radiological data and the results of pulmonary function tests. CONCLUSIONS: HRCT demonstrated bronchial reactivity in hyperresponsive patients and, unexpectedly, in healthy subjects. The applied pulmonary function tests failed to characterize bronchial reactions in the healthy subjects. Based on these results, HRCT is a useful tool by which to achieve a comprehensive understanding of the pathophysiological processes in asthmatic patients.

Adolescent↗
PubMed2004

[HRCT and bronchial asthma: visualization of the pathophysiologic changes of the pulmonary parenchyma after inhalation provocation].

PURPOSE: To characterize parenchymal lung affections morphologically in patients with asthma and healthy subjects by high -resolution computed tomography (HRCT) subsequent to histamine-triggered inhalation bronchoprovocation and salbutamol-induced broncholysis, and to compare the results with pulmonary function tests. MATERIALS AND METHODS: Fifteen asthmatics with bronchial hyperreactivity, with a > 20% decrease in FEV1 and a > 10 mmHg decrease in PaO(2) after bronchoprovocation (PC20%+), twelve asthmatics with a < 20% decrease in FEV1 and a > 10 mmHg decrease in PaO(2) after bronchoprovocation (PC20%-), and eight healthy persons without bronchial hyperreactivity underwent inhalation bronchoprovocation and broncholysis. Spirometer-triggered HRCT at high lung volumes was performed, and total and peripheral lung densities and the amount of solid lung structures, representing predominantly vessels, were measured. RESULTS: After bronchoprovocation, we observed significant decreases in total and peripheral lung densities in all groups (p < 0.0005), and a significant increase in lung densities subsequent to bronchodilation (p < 0.0002). The morphological alterations in solid lung structure were not significantly different after bronchoprovocation or broncholysis (p > 0.05), as compared to the baseline measurements. In hyperreactive patients, PaO(2) significantly decreased after provocation and significantly increased after lysis (p < 0.05). In PC20%+ asthmatics, a mean reduction of 27.8% in FEV1 was observed, which was < 20% in the other groups. No significant correlations were observed between radiological data and the results of pulmonary function tests. In healthy persons, we demonstrated highly significant parenchymal response to bronchoprovocation and broncholysis, which was not otherwise documented by pulmonary function tests. CONCLUSION: In both PC20%+ and PC20%- patients as well as in healthy individuals, HRCT was efficient in the evaluation of pathoanatomical alterations of the lung parenchyma subsequent to inhalation provocation. In healthy individuals, these parenchymal alterations were not documented by pulmonary function tests.

Adult↗
PubMed2003

Dendritic cell-based vaccination in solid cancer.

PURPOSE: Dendritic cell (DC)-based immunotherapy is rapidly emerging as a viable tool in cancer treatment. This approach has been used mostly in patients in the presence of defined tumor antigens such as melanoma. In this study, cancer patients with advanced disease that lacks defined tumor antigens were vaccinated with tumor lysate-pulsed DCs. PATIENTS AND METHODS: Twenty patients (pancreatic, hepatocellular, cholangiocellular, and medullary thyroid carcinoma) with stage IV disease were enrolled in the study. In 3-week intervals, freshly isolated autologous CD14 magnetic bead-selected monocytes were cultured in granulocyte-macrophage colony-stimulating factor and interleukin-4 to obtain immature DCs. These cells were pulsed with autologous tumor lysate and matured with tumor necrosis factor alpha. Mature DCs were applied into a groin lymph node, under ultrasound guidance. Adjuvant interleukin-2 (20,000 U/kg) was given subcutaneously daily, for 12 days, after each vaccination. Toxicity, tumor marker profile, immune response, and clinical response were determined. RESULTS: Vaccination was well tolerated. No physical signs of autoimmunity were detected. DC vaccination induced delayed-type hypersensitivity reactivity in 18 patients. Tumor marker responses were observed in eight patients. In addition, in three patients the generation of interferon gamma-positive T cells was induced during the vaccination. Objective changes in measurable lesions or tumor markers were evident in seven of 20 assessed patients. None of the patients was found to meet the criteria for partial or complete responses. CONCLUSION: These data indicate that vaccination with autologous tumor-pulsed DCs generated from peripheral blood is safe and can induce tumor-specific cellular cytotoxicity. Clinical responses are achievable, even in patients with advanced disease.

Adult↗
PubMedDate not supplied

Heat treatment of hepatocellular carcinoma cells: increased levels of heat shock proteins 70 and 90 correlate with cellular necrosis.

Immunotherapy, i.e. stimulation of the body's immune response against tumor cells, is a promising approach in cancer treatment. In this context, heat shock proteins (HSP) have been shown to function in tumor antigen chaperoning. HSP are evolutionarily conserved and show increased expression in response to chemical and physical stress. Two members of the HSP family, HSP 70 and 90, seem to further act as immunostimulating agents because of their possible involvement in tumor antigen presentation. We cultured the human hepatocellular carcinoma cell line HepG2 and investigated its HSP content under normal and hyperthermic conditions. Flow cytometry showed increased levels of HSP 70 and 90 after heat shock at 41.8 degrees C for 60 minutes, measured after a subsequent incubation time of five hours, as compared to untreated cells in vitro. We further observed a clear correlation between the HSP 70 and 90 levels and the necrotic cell subpopulation in heat shocked tumor cells. We conclude that HSP expression in HepG2 cells can be enhanced by heat shock treatment in vitro. We suggest that this mechanism can be exploited in increasing tumor immunogenicity.

Antibodies, Monoclonal↗