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In JoVE (1)
Other Publications (10)
Articles by Tobias Vogt in JoVE
JoVE Neuroscience
Coherence between Brain Cortical Function and Neurocognitive Performance during Changed Gravity Conditions
1Institute of Movement and Neurosciences, German Sport University Cologne, 2Deptartment of Surgical Skills, University of Toronto, 3School of Human Movement Studies, Institute of Health and Biomedical Innovation, Queensland University of Technology, 4Brain Products GmbH, Scientific Support, Gilching, Germany
The effect of weightlessness and hypergravity on both hemodynamic and electrophysiological processes in the brain is going to be followed during parabolic flight by EEG and NIRS techniques. A feasibility study of a more complex experiment, which is planned to carry out during medium- and long-term space flight.
Other articles by Tobias Vogt on PubMed
Double High-dose Chemotherapy with Adriamycin, Paclitaxel, Cyclophosphamide, and Thiotepa Followed by Autologous Peripheral Blood Stem Cell Transplantation in Women with Metastatic Breast Cancer
To determine the feasibility, time to progression, and event-free survival, twenty-two women with metastatic breast cancer received two cycles of high-dose chemotherapy (HDCT) followed by peripheral blood stem cell transplantation (PBSCT) early after first-line induction chemotherapy. The median age of the ten (45.5%) pre- and 12 (54.5%) postmenopausal women was 48 (range: 33-60) years. Sixteen patients (72.7%) had at least two or more metastatic sites involved. Protocol induction and mobilization chemotherapy including granulocyte-colony stimulating-factor (G-CSF) consisted of two cycles with adriamycin (60 mg/m(2)) i.v. and paclitaxel (200 mg/m(2)) i.v. After collection of at least 4 x 10(6)/kg bodyweight peripheral blood stem cells, the first HDCT-course of adriamycin (60 mg/m(2)), paclitaxel (200 mg/m(2)) cyclophosphamide (4 g/m(2)), and thiotepa (800 mg/m(2)) (ATCT) was given to at least stable disease (SD) patients. Six to eight weeks later, the second HDCT-ATCT was administered. Each HDCT-cycle was followed by PBSCT with a median of 3.81 x 10(6)/kg bodyweight CD-34 positive cells (range: 1.85-10.38). All women showed median leukocyte engraftment (>1,000 x 10(9)/l) on day +9.4 (range: 7-13) and median platelet engraftment (>20,000 x 10(9)/l) on day +12.3 (range: 8-15). There were no apparent differences in the clinical course and non-hematologic toxicity between the two HDCT-cycles. Of the 21 patients evaluable for response, eight (38.1%) patients achieved complete remission (CR), ten (47.6%) patients showed a partial remission (PR), two patients (9.5%) no change, and one patient (4.8%) progressive disease. After a median observation time of 36 (range 28-55) months, six (28.6%) women are alive, four (19.0%) of them in continuous CR, including two women with stable bone lesions, respectively, and 15 (71.4%) died due to progressive disease. Median time to progression (TTP) was 8 (range 4-19) months. A high initial response rate of early HDCT, including the most active drugs adriamycin and paclitaxel, can be achieved with tolerable toxicity in metastatic breast cancer. New approaches for maintaining primary tumor response achieved with efficacious high-dose chemotherapy are warranted.
Staurosporine Restores GTPgammaS Induced Block of Rapid Endocytosis in Chromaffin Cells
Fast capacitance measurements demonstrated that chromaffin cells retrieve membrane by several kinetically different pathways. Here, we show that rapid endocytosis is blocked and slow endocytosis reduced by intracellular application of GTPgammaS, an activator of G-proteins, but not by the competitive blocker GDPbetaS. The inhibition of rapid endocytosis by GTPgammaS can be restored with GDPbetaS or staurosporine completely. But only staurosporine partially abolishes the reduction of slow endocytosis by GTPgammaS. Besides triggering exocytosis, GTPgammaS elicits large exo- and endocytotic vesicles that contributed significantly to the total membrane traffic, indicating a third pathway of membrane shuttle.
Fibroblastic Reticular Cells in Lymph Nodes Regulate the Homeostasis of Naive T Cells
Interleukin 7 is essential for the survival of naive T lymphocytes. Despite its importance, its cellular source in the periphery remains poorly defined. Here we report a critical function for lymph node access in T cell homeostasis and identify T zone fibroblastic reticular cells in these organs as the main source of interleukin 7. In vitro, T zone fibroblastic reticular cells were able to prevent the death of naive T lymphocytes but not of B lymphocytes by secreting interleukin 7 and the CCR7 ligand CCL19. Using gene-targeted mice, we demonstrate a nonredundant function for CCL19 in T cell homeostasis. Our data suggest that lymph nodes and T zone fibroblastic reticular cells have a key function in naive CD4(+) and CD8(+) T cell homeostasis by providing a limited reservoir of survival factors.
Novel Function for Interleukin-7 in Dendritic Cell Development
Interleukin-7 (IL-7) is crucial for the development of T and B lymphocytes from common lymphoid progenitors (CLPs) and for the maintenance of mature T lymphocytes. Its in vivo role for dendritic cells (DCs) has been poorly defined. Here, we investigated whether IL-7 is important for the development or maintenance of different DC types. Bone marrow-derived DCs expressed the IL-7 receptor (IL-7R) and survived significantly longer in the presence of IL-7. Migratory DCs (migDCs) isolated from lymph nodes also expressed IL-7R. Surprisingly, IL-7R was not required for their maintenance but indirectly for their development. Conventional DCs (cDCs) and plasmacytoid DCs (pDCs) resident in lymph nodes and spleen were IL-7R(-). Using mixed bone marrow chimeras, we observed an intrinsic requirement for IL-7R signals in their development. As the number of CLPs but not myeloid progenitors was reduced in the absence of IL-7 signals, we propose that a large fraction of cDCs and pDCs derives from CLPs and shares not only the lymphoid origin but also the IL-7 requirement with lymphocyte precursors.
School Sport--a Neurophysiological Approach
The aim of this study was to identify neurophysiological correlates for previously reported positive effects of exercise on academic achievement in school children using a distributed source localization algorithm. Electro-cortical activity of 11 school children (9-10y) was recorded before and after a moderate 15-min bike exercise. Data were analyzed using standardized low resolution brain electromagnetic tomography (sLORETA) in the alpha (7.5-12.5Hz) and beta (12.5-35Hz) frequency range. We were able to show a significant increase in alpha activity post-exercise, which could be localized in the precuneus. Moreover a distinct decrease in beta activity could be noticed post-exercise in left temporal areas including Wernicke's area. We propose that apart from health-promoting aspects school sport serves a second even more important challenge. On a central level a well observed overall state of physical relaxation after exercise is reflected by a more synchronized state in the precuneus. We speculate this to be responsible for an increase in concentrativeness and cognitive function post-exercise. Moreover a previously reported increase in academic achievement post-exercise could be directly linked to exercise induced neuroplasticity in regions that are relevant for language processing.
Frontal EEG Asymmetry: the Effects of Sustained Walking in the Elderly
Numerous studies have been made in recent years addressing the effect of physical exercise on brain cortical activity and changes in mood. This research, however, was restricted to inadequate study designs in the elderly. In these times of an aging society, with the daily increasing interest in the benefits of physical exercise, investigations of the interrelationships of psycho-physiological elements of physical exercise seem to be progressively necessary. Using the model of frontal asymmetry, we hypothesized, that physical exercise by elderly persons at a self-selected pace increases left frontal alpha activity and is associated with a shift in mood to the positive. An electroencephalography (EEG) on two frontal positions (Fp1, Fp2) was made before and after walking at a self-selected pace for 45-60min and the state of the respective moods noted. The equation (right-left)/(right+left) was used to calculate frontal asymmetry as a marker of approach-related emotions. Key findings after walking were (1) a shift of the alpha-1 (7.5-10.0Hz) activation towards the right frontal brain areas as well as (2) an improvement in mood. Based on the frontal asymmetry model, an increase in the alpha-1 activation (p<0.05) might be associated with approach-related emotions. In conclusion, there is reason to believe that physical exercise programmes, as commonly practiced by the elderly, have beneficial effects on their general feeling of well-being. We were able to demonstrate this in this pilot study by applying only a comparatively simple and economically viable method.
Guiding Blind T Cells and Dendritic Cells: A Closer Look at Fibroblastic Reticular Cells Found Within Lymph Node T Zones
It is within the T cell rich zone of secondary lymphoid organs (SLO) that dendritic cells (DC) present the captured pathogens to recirculating T cells in order to activate the rare antigen-specific T cells. While we have made considerable progress in understanding the biology of mobile hematopoietic cells found within SLO, notably DC and lymphocytes, we still have a lot to learn about the sessile stromal cells. This review is focused on the recent progress made in our understanding of the fibroblastic reticular stromal cells that form the 'niches' within the T zone.
Brain Cortical Activity is Influenced by Exercise Mode and Intensity
Previous research suggests that different exercise modes and intensities lead to variations in brain cortical activity. However, because of variability and limitations in previous study designs, the mechanisms behind this link remain unclear. The aim of this study was to evaluate the effects on brain cortical activity that are dependent on exercise mode, intensity, and individual preferences and to localize these changes within the frontal, temporal, parietal, and occipital cortexes of the brain.
Expression of a Functional VEGFR-1 in Tumor Cells is a Major Determinant of Anti-PlGF Antibodies Efficacy
PlGF, one of the ligands for VEGFR-1, has been implicated in tumor angiogenesis. However, more recent studies indicate that genetic or pharmacological inhibition of PlGF signaling does not result in reduction of microvascular density in a variety of tumor models. Here we screened 12 human tumor cell lines and identified 3 that are growth inhibited by anti-PlGF antibodies in vivo. We found that efficacy of anti-PlGF treatment strongly correlates with VEGFR-1 expression in tumor cells, but not with antiangiogenesis. In addition, PlGF induced VEGFR-1 signaling and biological responses in tumor cell lines sensitive to anti-PlGF, but not in refractory tumor cell lines or in endothelial cells. Also, genetic ablation of VEGFR-1 signaling in the host did not affect the efficacy of PlGF blockade. Collectively, these findings suggest that the role of PlGF in tumorigenesis largely consists of promoting autocrine/paracrine growth of tumor cells expressing a functional VEGFR-1 rather than stimulation of angiogenesis.
Exercise, Mood and Cognitive Performance in Intellectual Disability - a Neurophysiological Approach
While numerous researches addressed the connection between physical exercise, changes in brain cortical activity and its relationship to psycho-physiological processes, most of these neuro-scientific studies were set up for healthy individuals. However, the benefits of exercise, such as well being, physical and cognitive health enhancements are also becoming increasingly important for intellectually disabled individuals. This study aimed to localize electroencephalographic activity changes in intellectually disabled individuals following a moderate running exercise for 30 min. An increase in cognitive performance and in mood was hypothesized to correlate with a decrease in fronto-temporal brain areas following exercise. Significant changes in cortical current density in frontal brain areas as well as decreases in perceived physical energy could be shown. Overall motivational states (including self-confidence and social acceptance) as well as positive mood increased significantly. However, no changes could be observed for the cognitive tasks following exercise. With respect to the data provided here there is reason to believe, that a self-selected pace running exercise, enhances self-esteem, coincided with cortical activity changes in fronto-temporal brain areas.
