1,020 research outputs found
The contribution of bone marrow-derived cells to angiogenesis and lymphangiogenesis in murine models of carcinogenesis
Cancer is a class of diseases in which a group of cells display uncontrolled growth (division beyond
the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes
metastasis (spread to other locations in the body via the circulatory system). In addition to tumor
cell-intrinsic genetic and epigenetic alterations, the tumor stroma, i.e. endothelial cells, pericytes,
fibroblasts and a diverse immune cell infiltrate, might substantially contribute to tumor progression,
metastatic potential and resistance to therapy.
I therefore investigated the influence of immune cells on the growth of tumors in the
Rip1Tag2 mouse insulinoma model of multistage carcinogenesis. I detected a strong infiltration of
myeloid cells, i.e. macrophages and granulocytes, into insulinomas. Functional experiments in vivo
revealed that depletion of macrophages in tumors led to reduced angiogenesis but did not affect
tumor growth.
During the characterization of the immune cell contribution to tumor growth in the Rip1Tag2
tumor model, I detected bone marrow-derived cells at unexpected sites. In particular, when I
analyzed the spatial contribution of GFP-tagged bone marrow cells in tumors of lymphangiogenic
Rip1Tag2;RipVEGF-C mice, I detected bone marrow-derived cells in lymphatic endothelium
surrounding the tumors.
Detailed analysis of the integrated GFP+-cells revealed the expression of a complete set of
markers that are characteristic for lymphatic endothelial cells, the cell surface proteins LYVE-1 and
Podoplanin, as well as the homeo-box transcription factor Prox-1. Depending on the analysis
technique applied, either confocal microscopy followed by 3D reconstitution or flow cytometry,
between 3 and 9% of lymphatic endothelial cells in tumors are derived from the bone marrow.
These studies were expanded to a second tumor model, the subcutaneous growth of TRAMP-C1
prostate cancer cells in syngenic mice, which confirmed the findings made in Rip1Tag2;
RipVEGF-C mice, and allowed to further substantiate the suggested ontogeny of the integrated,
bone marrow-derived cells.
Cell sorting and genetic lineage tracing experiments indicated that the bone marrow-derived
tumor lymphatic endothelial cells were at least partially derived from the myeloid lineage. Tumor
mice were adoptively transferred with labeled myeloid (progenitor) cells, and subsequent
integration of these cells into tumor lymphatic endothelium was detected. Cre/Lox technology
resulting in myeloid-specific marker gene expression was employed to come to similar conclusions
in a pure genetic experimental system without bone marrow cell-transfer or irradiation.
In a loss-of-function approach, macrophages were pharmacologically depleted in
Rip1Tag2;RipVEGF-C mice. Peritumoral lymphatic vessel coverage was found to be reduced in 2
macrophage-depleted mice as compared to control mice. Expression level analysis of the
lymphangiogenic factors VEGF-C and VEGF-D by tumor-infiltrating macrophages indicated that
their contribution to lymphangiogenesis by supplying growth factors is negligible and that the
reduced lymphangiogenesis might indeed come from the reduced availability of macrophages as
building blocks of lymphatic endothelia.
The same plasticity of myeloid cells I detected in vivo was also observed in vitro, where
bone marrow-derived macrophages start forming tube like structures and also start expressing
lymphatic endothelial markers, when cultured under pro-inflammatory and endothelial specific
conditions.
In conclusion, this data indicates a myeloid origin of cells that trans-differentiate into
lymphatic endothelial cells in an inflammatory tumor environment.
The increasing use of non-invasive imaging technologies prompted us to evaluate an
approach resulting in bioluminescent pancreatic insulinoma, principally an improved Rip1Tag2
tumor model of multistage pancreatic β-cell carcinogenesis. I therefore constructed a bicistronic
expression cassette in which SV40 early region is followed by an internal ribosomal entry site and
a firefly luciferase coding sequence, under the transcriptional control of the Rat insulin promoter 1.
Transgenic expression in mice resulted in β-cell carcinogenesis that could be monitored noninvasively
by in vivo bioluminescence. Numerous tumors of different malignancy stages can be
detected in individual mice, indicating that this model recapitulates multistage carcinogenesis. In
addition, in this mouse strain called RL-1 (RipTag-IRES-Luciferase line 1), due to the very stringent expression exclusively in the β-cells of Langerhans islets, we could determine micro-metastasis in
liver via luciferase expression of metastatic cells. This mouse line will be of value to study antitumoral
therapeutic approaches in real-time, as well as to define roles for tumor-promoting as well
as metastasis-related genes when crossed to other transgenic or gene-targeted mice
The impact of social support and resilience on surgical outcomes
Social support and resilience have been shown to reduce recovery times after major operations, as well as predict levels of post-operative pain. This study aims to determine whether social support and resilience modulate medical outcomes parameters and perceptions of recovery after a surgical intervention. Post-operative patients were recruited from an inner-city, safety net, level 1 trauma center prior to discharge. They completed questionnaires on social support (Medical Outcomes Study - Social Support Survey MOS-SSS), resilience (Brief Resilience Scale BRS), and overall health (Medical Outcomes Study â Short Form 36 MOS-SF36). Patients then completed the MOS-SF36 questionnaire approximately six and twelve weeks after surgical treatment. Preliminary results from recruited patients offer no conclusion regarding social support and outcome measures, but a significant positive relationship between resilience and patient-reported quality of life was seen (Spearman's Rho = 0.606). Resilience was also highest among patients in the surgical oncology service, relative to the other two surgical cohorts
Ergotherapeutische Domizilbehandlung bei erwachsenen Klienten nach Schlaganfall mit Fokus auf die Aktivitäten des täglichen Lebens sowie die instrumentellen Aktivitäten des täglichen Lebens
Arm-leg pressure gradients on late follow-up after coarctation repair: Possible causes and implications
Seventeen years after coarctation repair, 36 patients were studied by magnetic resonance imaging and exercise testing to measure residual anatomical stenosis and hormonal response to exercise, and to evaluate their effect on arm-leg gradients and on exercise hypertension. The systolic arm pressure, leg pressure and arm-leg gradient were measured at rest and during exercise. Active renin and catecholamines were measured in the plasma at rest and after peak exercise. On magnetic resonance imaging 18 patients had residual stenosis of less than 30% (group I) and 18 had residual stenosis of equal to or more than 30% (group II). At peak exercise, the arm pressure was 235 (133-296) mmHg in group I and 241 (157-286) mmHg in group II (ns), the leg pressure was 138 (111-173) mmHg in group I and 114 (75-154)mmHg in group II (P=0¡002). The adrenalin increase from rest to exercise was 32¡7 Âą 9¡1 pg . ml â1 in the patients with exercise hypertension and 3¡1 Âą 4¡7 pg. mlâ1 in the patients who remained normotensive during exercise (P=0¡02). In conclusion, residual anatomical stenosis leads to a pressure drop in the legs, which influences the arm-leg gradient. Arm hypertension is not related to anatomical narrowing but to interaction of enhanced sympathetic nerve activity and structural and functional abnormality of the precoarctation vessels. (Eur Heart J 1996; 17: 1572-1575
Two-step Doppler cooling of a three-level ladder system with an intermediate metastable level
Doppler laser cooling of a three-level ladder system using two near-resonant
laser fields is analyzed in the case of the intermediate level being metastable
while the upper level is short-lived. Analytical as well as numerical results
for e.g. obtainable scattering rates and achievable temperatures are presented.
When appropriate, comparisons with two-level single photon Doppler laser
cooling is made. These results are relevant to recent experimental Doppler
laser cooling investigations addressing intercombination lines in alkali-earth
metal atoms and quadrupole transitions in alkali-earth metal ions.Comment: accepted by Phys Rev
Whiplash and Concussion: Similar Acute Changes in Middle-Latency SEPs
Objective: Middle-latency somatosensory evoked potentials (SEPs) following median nerve stimulation can provide a sensitive measure of cortical function. We sought to determine whether the mechanical forces of whiplash injury or concussion alter normal processing of middle-latency SEPs. Methods: In a cross-sectional pilot study 20 subjects with whiplash were investigated (50% between 0.5-2 months and 50% between 6-41 months post injury) and compared to 83 healthy subjects using a standard middle-latency SEP procedure. In a subsequent prospective study subjects with either acute whiplash (n=13) or Grade 3 concussion (n=16) were investigated within 48 hours and again three months post injury. Results: In the pilot study the middle-latency SEP component N60 was significantly increased in the ten subjects investigated within two months after whiplash. In contrast, the ten subjects examined more than six months after injury showed normal latencies. In the prospective study N60 latencies were increased after whiplash and concussion when tested within 48 hours of injury. At three months, latencies were improved though still significantly different from controls post whiplash and concussion. Conclusion: Both whiplash injury and concussion alter processing of the middle-latency SEP component N60 in the acute post traumatic period. The acute changes appear to normalize between three-six months post injury. The SEP similarities suggest that the overlapping clinical symptomatology post whiplash and concussion may reflect a similar underlying mechanism of rotational mild traumatic brain injur
ORSA Schweiz : wo stehen die Schweizer Versicherer? : Studie 2017
Die vorliegende Studie untersucht den Stand der Umsetzung des ORSA durch Schweizer Direktversicherer, Rßckversicherer und Krankenversicherer. Die Erkenntnisse aus einer standardisierten Befragung und Expertengesprächen deuten darauf hin, dass die befragten Versicherer ORSA zwar implementiert haben, dieses aber noch wenig in die Entscheidungsprozesse eingebettet ist. Ziel der Studie ist es, die Erfahrungen aus der ersten Durchfßhrung des ORSA hinsichtlich organisatorischer Einbettung, Herausforderungen sowie Art und Anzahl von angewandten Szenarien, Berechnungen und Risiken in der Schweiz darzustellen. Aus den Ergebnissen lassen sich Status Quo der Implementierung, Nutzen und Handlungsfelder fßr die kommende Durchfßhrung ableiten. Die Umsetzung von ORSA ist gemäss den Befragten bereits weit vorangeschritten. Die Mehrheit gibt an, ORSA bereits vollumfänglich implementiert oder die wichtigsten Anpassungen umgesetzt zu haben. Die Beurteilung des Nutzens von ORSA und wie ORSA als Steuerungsinstrument eingesetzt wird, fällt aber bei den Befragten sehr unterschiedlich aus. Die grÜssten Herausforderungen der Umsetzung bestanden darin, eine Mehrjahresperspektive einzunehmen, den ORSA-Prozess in bestehende Prozesse einzubetten sowie die Szenarien, und insbesondere ein existenzbedrohendes Szenario, zu bestimmen und zu quantifizieren. Die Hauptverantwortung der Durchfßhrung liegt mehrheitlich beim Risikomanagement, bei kleineren Versicherern zudem stark beim Aktuariat. Auch geben grÜssere Versicherer eher an, unternehmensßbergreifend fßr die ORSA-Erstellung zusammenzuarbeiten. Die Resultate zeigen, dass der Verwaltungsrat grÜsserer Unternehmen stärker in die Steuerung des ORSA-Prozesses involviert ist. Die Beurteilung des Einflusses von ORSA auf strategische Geschäftsprozesse hängt stark mit dem Entwicklungsstand der ORSA-Implementierung zusammen. Am stärksten hat ORSA die Formulierung von Risikoappetit und -toleranz tangiert. Kranken- und Direktversicherer verweisen zudem auf das Asset Management. Demgegenßber steht bei den Rßckversicherern die Dividendenplanung stark im Fokus. Positiv beeinflusst zu haben scheint ORSA bereits die unternehmensßbergreifende Zusammenarbeit und den Dialog zwischen Bereichen und Hierarchien. Deutliche Unterschiede zeigen sich in den Aussagen nach Geschäftsfeld. Direktversicherer geben einen geringeren Durchfßhrungsaufwand an als Rßck- und Krankenversicherer. Kranken- und Direktversicherer nahmen eher externe Unterstßtzung in Anspruch im Vergleich zu Rßckversicherern. Auch beim Umfang bestehen Unterschiede zwischen den Sparten. Rßckversicherer haben tendenziell mehr Szenarien betrachtet und umfangreichere Berichte eingereicht. Die Verfßgbarkeit der personellen Ressourcen scheint vor allem bei Krankenversicherern ein Thema zu sein. Die Mehrheit der Versicherer arbeitet mit einer 3-Jahres-Betrachtung. Als Risiko-mindernde Massnahmen wurden vor allem die Rßckversicherung sowie die Anpassung der Anlagestrategie verwendet. Zukßnftig wßnschen sich viele der befragten Unternehmen eine stärkere Praxisorientierung, mehr Konstanz und eine stärkere Berßcksichtigung des Proportionalitätsprinzips seitens der Aufsicht. Unter den grÜsseren Versicherern gibt es auch Stimmen, die sich eine stringentere Anlehnung an Prinzipien wßnschen. Abhängig des Risikomanagements stehen Schweizer Versicherer nun vor unterschiedlichen Herausforderungen. Während bei einigen Versicherern die Abbildung der Mehrjahresplanung und Sensibilisierung der Entscheidungsgremien im Fokus steht, geht es bei anderen um die Etablierung von ORSA als Steuerungsinstrument
Non-targeted metabolic profiling of BW312 Hordeum vulgare semi dwarf mutant using UHPLC coupled to QTOF high resolution mass spectrometry
Abstract Barley (Hordeum vulgare) is the fourth crop cultivated in the world for human consumption and animal feed, making it important to breed healthy and productive plants. Among the threats for barley are lodging, diseases, and pathogens. To avoid lodging, dwarf and semi-dwarf mutants have been selected through breeding processes. Most of these mutants are affected on hormonal biosynthesis or signalling. Here, we present the metabolic characterization of a brassinosteroid insensitive semi-dwarf mutant, BW312. The hormone profile was determined through a targeted metabolomics analysis by UHPLC-triple quadrupole-MS/MS, showing an induction of gibberellic acid and jasmonic acid in the semi-dwarf mutant. A non-targeted metabolomics analysis by UHPLC-QTOF-MS/MS revealed a differential metabolic profile, with 16 and 9 metabolites showing higher intensities in the mutant and wild-type plants respectively. Among these metabolites, azelaic acid was identified. Gibberellic acid, jasmonic acid, and azelaic acid are involved in pathogen resistance, showing that this semi-dwarf line has an enhanced basal pathogen resistance in absence of pathogens, and therefore is of interest in breeding programs to fight against lodging, but also probably to increase pathogen resistance
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Antagonizing CD105 enhances radiation sensitivity in prostate cancer.
Radiation therapy is the primary intervention for nearly half of the patients with localized advanced prostate cancer and standard of care for recurrent disease following surgery. The development of radiation-resistant disease is an obstacle for nearly 30-50% of patients undergoing radiotherapy. A better understanding of mechanisms that lead to radiation resistance could aid in the development of sensitizing agents to improve outcome. Here we identified a radiation-resistance pathway mediated by CD105, downstream of BMP and TGF-β signaling. Antagonizing CD105-dependent BMP signaling with a partially humanized monoclonal antibody, TRC105, resulted in a significant reduction in clonogenicity when combined with irradiation. In trying to better understand the mechanism for the radio-sensitization, we found that radiation-induced CD105/BMP signaling was sufficient and necessary for the upregulation of sirtuin 1 (SIRT1) in contributing to p53 stabilization and PGC-1Îą activation. Combining TRC105 with irradiation delayed DNA damage repair compared to irradiation alone. However, in the absence of p53 function, combining TRC105 and radiation resulted in no reduction in clonogenicity compared to radiation alone, despite similar reduction of DNA damage repair observed in p53-intact cells. This suggested DNA damage repair was not the sole determinant of CD105 radio-resistance. As cancer cells undergo an energy deficit following irradiation, due to the demands of DNA and organelle repair, we examined SIRT1's role on p53 and PGC-1Îą with respect to glycolysis and mitochondrial biogenesis, respectively. Consequently, blocking the CD105-SIRT1 axis was found to deplete the ATP stores of irradiated cells and cause G2 cell cycle arrest. Xenograft models supported these findings that combining TRC105 with irradiation significantly reduces tumor size over irradiation alone (p valueâ=â10-9). We identified a novel synthetic lethality strategy of combining radiation and CD105 targeting to address the DNA repair and metabolic addiction induced by irradiation in p53-functional prostate cancers
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