149 research outputs found

    Finite-Horizon Robust Integrated Guidance-Control of A Moving-Mass Actuated Kinetic Warhead

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    A game-theoretic approach to the design of robust integrated guidance-control system for a moving-mass actuated kinetic warhead is presented. Feedback linearized form of the kinetic warhead dynamics and a high-order target model are used in the formulation. Nonlinear feedback solution to the robust finite-horizon target interception problem is derived using the recently developed multi-stepping algorithm. Due to its computational efficiency, the multi-stepping algorithm is suitable for real-time implementation. Interception of targets in the presence of modeling uncertainties is demonstrated in nonlinear engagement simulations

    Monotherapy efficacy of blood-brain barrier permeable small molecule reactivators of protein phosphatase 2A in glioblastoma

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    Glioblastoma is a fatal disease in which most targeted therapies have clinically failed. However, pharmacological reactivation of tumour suppressors has not been thoroughly studied as yet as a glioblastoma therapeutic strategy. Tumour suppressor protein phosphatase 2A is inhibited by non-genetic mechanisms in glioblastoma, and thus, it would be potentially amendable for therapeutic reactivation. Here, we demonstrate that small molecule activators of protein phosphatase 2A, NZ-8-061 and DBK-1154, effectively cross the in vitro model of blood-brain barrier, and in vivo partition to mouse brain tissue after oral dosing. In vitro, small molecule activators of protein phosphatase 2A exhibit robust cell-killing activity against five established glioblastoma cell lines, and nine patient-derived primary glioma cell lines. Collectively, these cell lines have heterogeneous genetic background, kinase inhibitor resistance profile and stemness properties; and they represent different clinical glioblastoma subtypes. Moreover, small molecule activators of protein phosphatase 2A were found to be superior to a range of kinase inhibitors in their capacity to kill patient-derived primary glioma cells. Oral dosing of either of the small molecule activators of protein phosphatase 2A significantly reduced growth of infiltrative intracranial glioblastoma tumours. DBK-1154, with both higher degree of brain/blood distribution, and more potent in vitro activity against all tested glioblastoma cell lines, also significantly increased survival of mice bearing orthotopic glioblastoma xenografts. In summary, this report presents a proof-of-principle data for blood-brain barrier-permeable tumour suppressor reactivation therapy for glioblastoma cells of heterogenous molecular background. These results also provide the first indications that protein phosphatase 2A reactivation might be able to challenge the current paradigm in glioblastoma therapies which has been strongly focused on targeting specific genetically altered cancer drivers with highly specific inhibitors. Based on demonstrated role for protein phosphatase 2A inhibition in glioblastoma cell drug resistance, small molecule activators of protein phosphatase 2A may prove to be beneficial in future glioblastoma combination therapies.Peer reviewe

    The FU gene and its possible protein isoforms

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    BACKGROUND: FU is the human homologue of the Drosophila gene fused whose product fused is a positive regulator of the transcription factor Cubitus interruptus (Ci). Thus, FU may act as a regulator of the human counterparts of Ci, the GLI transcription factors. Since Ci and GLI are targets of Hedgehog signaling in development and morphogenesis, it is expected that FU plays an important role in Sonic, Desert and/or Indian Hedgehog induced cellular signaling. RESULTS: The FU gene was identified on chromosome 2q35 at 217.56 Mb and its exon-intron organization determined. The human developmental disorder Syndactyly type 1 (SD1) maps to this region on chromosome 2 and the FU coding region was sequenced using genomic DNA from an affected individual in a linked family. While no FU mutations were found, three single nucleotide polymorphisms were identified. The expression pattern of FU was thoroughly investigated and all examined tissues express FU. It is also clear that different tissues express transcripts of different sizes and some tissues express more than one transcript. By means of nested PCR of specific regions in RT/PCR generated cDNA, it was possible to verify two alternative splicing events. This also suggests the existence of at least two additional protein isoforms besides the FU protein that has previously been described. This long FU and a much shorter isoform were compared for the ability to regulate GLI1 and GLI2. None of the FU isoforms showed any effects on GLI1 induced transcription but the long form can enhance GLI2 activity. Apparently FU did not have any effect on SUFU induced inhibition of GLI. CONCLUSIONS: The FU gene and its genomic structure was identified. FU is a candidate gene for SD1, but we have not identified a pathogenic mutation in the FU coding region in a family with SD1. The sequence information and expression analyses show that transcripts of different sizes are expressed and subjected to alternative splicing. Thus, mRNAs may contain different 5'UTRs and encode different protein isoforms. Furthermore, FU is able to enhance the activity of GLI2 but not of GLI1, implicating FU in some aspects of Hedgehog signaling

    Monotherapy efficacy of blood-brain barrier permeable small molecule reactivators of protein phosphatase 2A in glioblastoma

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    Glioblastoma is a fatal disease in which most targeted therapies have clinically failed. However, pharmacological reactivation of tumour suppressors has not been thoroughly studied as yet as a glioblastoma therapeutic strategy. Tumour suppressor protein phosphatase 2A is inhibited by non-genetic mechanisms in glioblastoma, and thus, it would be potentially amendable for therapeutic reactivation. Here, we demonstrate that small molecule activators of protein phosphatase 2A, NZ-8-061 and DBK-1154, effectively cross the in vitro model of blood–brain barrier, and in vivo partition to mouse brain tissue after oral dosing. In vitro, small molecule activators of protein phosphatase 2A exhibit robust cell-killing activity against five established glioblastoma cell lines, and nine patient-derived primary glioma cell lines. Collectively, these cell lines have heterogeneous genetic background, kinase inhibitor resistance profile and stemness properties; and they represent different clinical glioblastoma subtypes. Moreover, small molecule activators of protein phosphatase 2A were found to be superior to a range of kinase inhibitors in their capacity to kill patient-derived primary glioma cells. Oral dosing of either of the small molecule activators of protein phosphatase 2A significantly reduced growth of infiltrative intracranial glioblastoma tumours. DBK-1154, with both higher degree of brain/blood distribution, and more potent in vitro activity against all tested glioblastoma cell lines, also significantly increased survival of mice bearing orthotopic glioblastoma xenografts. In summary, this report presents a proof-of-principle data for blood–brain barrier—permeable tumour suppressor reactivation therapy for glioblastoma cells of heterogenous molecular background. These results also provide the first indications that protein phosphatase 2A reactivation might be able to challenge the current paradigm in glioblastoma therapies which has been strongly focused on targeting specific genetically altered cancer drivers with highly specific inhibitors. Based on demonstrated role for protein phosphatase 2A inhibition in glioblastoma cell drug resistance, small molecule activators of protein phosphatase 2A may prove to be beneficial in future glioblastoma combination therapies.</p

    γ-H2AX Kinetics as a Novel Approach to High Content Screening for Small Molecule Radiosensitizers

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    Persistence of γ-H2AX after ionizing radiation (IR) or drug therapy is a robust reporter of unrepaired DNA double strand breaks in treated cells.DU-145 prostate cancer cells were treated with a chemical library ±IR and assayed for persistence of γ-H2AX using an automated 96-well immunocytochemistry assay at 4 hours after treatment. Hits that resulted in persistence of γ-H2AX foci were tested for effects on cell survival. The molecular targets of hits were validated by molecular, genetic and biochemical assays and in vivo activity was tested in a validated Drosophila cancer model.We identified 2 compounds, MS0019266 and MS0017509, which markedly increased persistence of γ-H2AX, apoptosis and radiosensitization in DU-145 cells. Chemical evaluation demonstrated that both compounds exhibited structurally similar and biochemical assays confirmed that these compounds inhibit ribonucleotide reductase. DNA microarray analysis and immunoblotting demonstrates that MS0019266 significantly decreased polo-like kinase 1 gene and protein expression. MS0019266 demonstrated in vivo antitumor activity without significant whole organism toxicity.MS0019266 and MS0017509 are promising compounds that may be candidates for further development as radiosensitizing compounds as inhibitors of ribonucleotide reductase

    Inhibition of the Nuclear Import of Cubitus Interruptus by Roadkill in the Presence of Strong Hedgehog Signal

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    Hedgehog (Hh) signalling plays an important role in various developmental processes by activating the Cubitus interruptus (Ci)/Glioblastoma (Gli) family of transcription factors. In the process of proper pattern formation, Ci activity is regulated by multiple mechanisms, including processing, trafficking, and degradation. However, it remains elusive how Ci distinctly recognizes the strong and moderate Hh signals. Roadkill (Rdx) induces Ci degradation in the anterior region of the Drosophila wing disc. Here, we report that Rdx inhibited Ci activity by two different mechanisms. In the region abutting the anterior/posterior boundary, which receives strong Hh signal, Rdx inhibited the nuclear import of Ci by releasing importin α3 from Ci. In this region, Rdx negatively regulated the expression of transcription factor Knot/Collier. In farther anterior regions receiving moderate levels of Hh signal, Rdx induced Ci degradation, as reported previously. Thus, two different mechanisms by which Rdx negatively regulates Ci may play an important role in the fine-tuning of Hh responses

    Metabolic Rift or Metabolic Shift? Dialectics, Nature, and the World-Historical Method

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    Abstract In the flowering of Red-Green Thought over the past two decades, metabolic rift thinking is surely one of its most colorful varieties. The metabolic rift has captured the imagination of critical environmental scholars, becoming a shorthand for capitalism’s troubled relations in the web of life. This article pursues an entwined critique and reconstruction: of metabolic rift thinking and the possibilities for a post-Cartesian perspective on historical change, the world-ecology conversation. Far from dismissing metabolic rift thinking, my intention is to affirm its dialectical core. At stake is not merely the mode of explanation within environmental sociology. The impasse of metabolic rift thinking is suggestive of wider problems across the environmental social sciences, now confronted by a double challenge. One of course is the widespread—and reasonable—sense of urgency to evolve modes of thought appropriate to an era of deepening biospheric instability. The second is the widely recognized—but inadequately internalized—understanding that humans are part of nature

    Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry

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    Hantaviren und Nagetiere in Deutschland: Das Netzwerk „Nagetier-übertragene Pathogene”

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    ZusammenfassungHantavirus-Infektionen sind in Deutschland seit etwa 25 Jahren bekannt. Die durchschnittliche Antikörperprävalenz in der Bevölkerung liegt bei ca. 1 bis 2%. Nach Einführung der Meldepflicht im Jahr 2001 sind jährlich durchschnittlich etwa 70 bis 240 Fälle gemeldet worden. Im Jahr 2005 und insbesondere im Jahr 2007 ist jedoch ein deutlicher Anstieg der Zahl der gemeldeten Fälle registriert worden. Die am meisten betroffenen Regionen lagen in den Bundesländern Baden-Württemberg, Bayern, Nordrhein-Westfalen und Niedersachsen. Im Gegensatz zur gut dokumentierten Situation beim Menschen ist die Kenntnis der geografischen Verbreitung und Häufigkeit von Hantavirus-Infektionen in den Nagetier-Reservoiren und deren Schwankungen sehr begrenzt. Aus diesem Grund wurde in Deutschland das Netzwerk „Nagetier-übertragene Pathogene“ etabliert, das interdisziplinäre Untersuchungen zur Nagetier-Populationsdynamik, Prävalenz und Evolution von Hantaviren und anderen Nagetier-assoziierten Zoonoseerregern und den zugrunde liegenden Mechanismen sowie deren Auswirkungen auf die Häufigkeit humaner Infektionen erlaubt. Ein Monitoring von Hantaviren in Nagetieren wurde in Endemiegebieten (Baden-Württemberg, Bayern, Nordrhein-Westfalen, Niedersachsen) und Regionen mit einer geringen Zahl humaner Fälle (Mecklenburg-Vorpommern, Brandenburg, Sachsen, Sachsen-Anhalt, Thüringen, Schleswig-Holstein, Hessen, Rheinland-Pfalz) initiiert. Insgesamt wurde eine breite geographische Verbreitung des Puumalavirus (PUUV) in Rötelmäusen und des Tulavirus in Microtus-Mäusen dokumentiert. Dobrava-Belgrad-Virus-positive Apodemus-Mäuse wurden bisher ausschließlich in Brandenburg, Mecklenburg-Vorpommern und Niedersachsen gefunden. In den Hantavirus-Ausbruchsgebieten in Baden-Württemberg, Bayern, Nordrhein-Westfalen und Niedersachsen wurde bei Rötelmäusen eine hohe PUUV-Prävalenz beobachtet. Initiale Longitudinalstudien in Nordrhein-Westfalen (Stadt Köln), Bayern (Niederbayern) und Niedersachsen (ländliche Region bei Osnabrück) zeigten ein stabiles Vorkommen des PUUV in den Rötelmaus-Populationen. Neben den Untersuchungen zu Hantaviren ist auch mit Studien zum Vorkommen von anderen Nagetier-assoziierten Zoonoseerregern begonnen worden. Die begonnenen Longitudinalstudien werden Schlussfolgerungen zur Evolution von Hantaviren und anderen Nagetierassoziierten Erregern und zu Veränderungen in deren Häufigkeit und Verbreitung ermöglichen. Diese Untersuchungen werden zukünftig eine verbesserte Risikoabschätzung für die Gefährdung der Bevölkerung ermöglichen, die auch die möglichen zukünftigen Klimawandel-bedingten Veränderungen in der Epidemiologie Nagetier-assoziierter Zoonoseerreger berücksichtigt

    Phase shift in the REM sleep rhythm

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    The periodic alternation between REM and NREM sleep was analyzed. Usually, sleep records of consecutive nights of a subject are regarded to be independent events. However, it may be that consecutive nights are realizations of a continuously ongoing rhythm. This was tested in the present study. The temporal patterns of REM and NREM sleep in sequences of about 30 consecutive nights for 3 subjects were analyzed. The results show that only the onset of the first REM sleep phase during any one night may be predicted from the sleep onset time, whereas a systematic phase shift between consecutive nights was observed in the later REM sleep phases. Thus, the onset of later REM sleep phases is better predicted by assuming a rhythm with stable period length which controls the appearance of REM sleep phases in successive nights. Under the experimental conditions the phase shift was between 5 and 10 min per 24 hrs for the 3 subjects. The result is accordance with Kleitman's basic rest activity cycle (BRAC) hypothesis
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