149 research outputs found
THE PRECLINICAL AND CLINICAL PHARMACOLOGY OF BENZALDEHYDE DIMETHANE SULFONATE (BEN) FOR THE TREATMENT OF RENAL CELL CARCINOMA
Over 65,000 people acquired renal cell carcinoma (RCC) and over 13,500 people died from the disease in the United States in 2012. The median survival for persons with metastatic disease is 13 months. Recent research has identified new targets for this disease and new targeted therapies have been developed. Despite this, the overall survival remains poor, and there remains a need for new therapies for RCC. Benzaldehyde dimethane sulfonate (BEN, DMS612) is a bifunctional alkylating agent with activity against renal cell carcinoma. The goal of the research conducted was to evaluate the preclinical and clinical pharmacology of BEN.
Benzaldehyde dimethane sulfonate is stable in plasma but is metabolized in blood by aldehyde dehydrogenase into an acid that decomposes in aqueous and biological matrices. Furthermore, the acid product decomposes into 6 different species of which none are as active as BEN in the renal carcinoma cells that we have tested. We also found that BEN had greater activity in renal carcinoma cell lines that expressed higher levels of aldehyde dehydrogenase. This led us to believe that BEN acts as a pro-drug with its main carboxylic acid metabolite exerting the activity against renal carcinoma cell lines. We determined that BEN is rapidly metabolized in mice and that the pretreatment of mice with the aldehyde dehydrogenase inhibitor disulfiram greatly increases the exposure to BEN. Furthermore the carboxylic decomposition products that were detected in vitro were also found in the mice along with corresponding glucuronides. Also, we found that BEN when administered to patients is very rapidly metabolized and the same glucuronides generated in mice were also detected in humans. The maximum tolerated dose in a phase I clinical trial in humans was 9.0 mg/m2. The dose limiting toxicity was neutropenia. The information generated in this dissertation will be instrumental in the future clinical development of BEN
LABY : un support d'aide à l'évaluation de choix de conception d'IHM pour le contrôle aérien
International audienceThe iterative approach in the development of Human Machine Interfaces involves the validation of design choices on both aspects of design and means of interaction. In the case of complex interfaces, conduct evaluations of such choices can be very difficult and expensive. In the field of air traffic control, especially for the design of the controllers' radar display, a simulation tool for high-fidelity usage scenarios LABY has been developed to enable ergonomists and engineers to evaluate HMI solutions in a simplified and controllable environment. In this paper we present the use of LABY in three experiments realized in order to design an innovative interface for air traffic controllers
Evaluation of head-free eye tracking as an input device for air traffic control
International audienceThe purpose of this study was to investigate the possibility to integrate a free head motion eye-tracking system as input device in air traffic control (ATC) activity. Sixteen participants used an eye tracker to select targets displayed on a screen as quickly and accurately as possible. We assessed the impact of the presence of visual feedback about gaze position and the method of target selection on selection performance under different difficulty levels induced by variations in target size and target-to-target separation. We tend to consider that the combined use of gaze dwell-time selection and continuous eye-gaze feedback was the best condition as it suits naturally with gaze displacement over the ATC display and free the hands of the controller, despite a small cost in terms of selection speed. In addition, target size had a greater impact on accuracy and selection time than target distance. These findings provide guidelines on possible further implementation of eye tracking in ATC everyday activity
The Ultraviolet Imaging Telescope: Instrument and Data Characteristics
The Ultraviolet Imaging Telescope (UIT) was flown as part of the Astro
observatory on the Space Shuttle Columbia in December 1990 and again on the
Space Shuttle Endeavor in March 1995. Ultraviolet (1200-3300 Angstroms) images
of a variety of astronomical objects, with a 40 arcmin field of view and a
resolution of about 3 arcsec, were recorded on photographic film. The data
recorded during the first flight are available to the astronomical community
through the National Space Science Data Center (NSSDC); the data recorded
during the second flight will soon be available as well. This paper discusses
in detail the design, operation, data reduction, and calibration of UIT,
providing the user of the data with information for understanding and using the
data. It also provides guidelines for analyzing other astronomical imagery made
with image intensifiers and photographic film.Comment: 44 pages, LaTeX, AAS preprint style and EPSF macros, accepted by PAS
Mice Expressing Low Levels of CalDAG-GEFI Exhibit Markedly Impaired Platelet Activation With Minor Impact on HemostasisHighlights
OBJECTIVE: The tight regulation of platelet adhesiveness, mediated by the αIIbβ3 integrin, is critical for hemostasis and prevention of thrombosis. We recently demonstrated that integrin affinity in platelets is controlled by the guanine nucleotide exchange factor, CalDAG-GEFI (CD-GEFI), and its target, RAP1. In this study, we investigated whether low-level expression of CD-GEFI leads to protection from thrombosis without pathological bleeding in mice.
APPROACH AND RESULTS: Cdg1(low) mice were generated by knockin of human CD-GEFI cDNA into the mouse Cdg1 locus. CD-GEFI expression in platelets from Cdg1(low) mice was reduced by ≈90% when compared with controls. Activation of RAP1 and αIIbβ3 was abolished at low agonist concentrations and partially inhibited at high agonist concentrations in Cdg1(low) platelets. Consistently, the aggregation response of Cdg1(low) platelets was weaker than that of wild-type platelets, but more efficient than that observed in Cdg1(-/-) platelets. Importantly, Cdg1(low) mice were strongly protected from arterial and immune complex-mediated thrombosis, with only minimal impact on primary hemostasis.
CONCLUSIONS: Together, our studies suggest the partial inhibition of CD-GEFI function as a powerful new approach to safely prevent thrombotic complications
Warm gas phase chemistry as possible origin of high HDO/H2O ratios in hot and dense gases: application to inner protoplanetary discs
The origin of Earth oceans is controversial. Earth could have acquired its
water either from hydrated silicates (wet Earth scenario) or from comets (dry
Earth scenario). [HDO]/[H2O] ratios are used to discriminate between the
scenarios. High [HDO]/[H2O] ratios are found in Earth oceans. These high ratios
are often attributed to the release of deuterium enriched cometary water ice,
which was formed at low gas and dust temperatures. Observations do not show
high [HDO]/[H2O] in interstellar ices. We investigate the possible formation of
high [HDO]/[H2O] ratios in dense (nH> 1E6 cm^{-3}) and warm gas (T=100-1000 K)
by gas-phase photochemistry in the absence of grain surface chemistry. We
derive analytical solutions, taking into account the major neutral-neutral
reactions for gases at T>100 K. The chemical network is dominated by
photodissociation and neutral-neutral reactions. Despite the high gas
temperature, deuterium fractionation occurs because of the difference in
activation energy between deuteration enrichment and the back reactions. The
analytical solutions were confirmed by the time-dependent chemical results in a
1E-3 MSun disc around a typical TTauri star using the photochemical code
ProDiMo. The ProDiMo code includes frequency-dependent 2D dust-continuum
radiative transfer, detailed non-LTE gas heating and cooling, and hydrostatic
calculation of the disc structure. Both analytical and time-dependent models
predict high [HDO]/[H2O] ratios in the terrestrial planet forming region (< 3
AU) of circumstellar discs. Therefore the [HDO]/[H2O] ratio may not be an
unique criterion to discriminate between the different origins of water on
Earth.Comment: accepted for publication in MNRA
Scutellaria Baicalensis Enhances 5-Fluorouracil-Based Chemotherapy via Inhibition of Proliferative Signaling Pathways
Fluoropyridine-based chemotherapy remains the most widely used treatment for colorectal cancer (CRC). In this study, we investigated the mechanism by which the natural product Scutellaria baicalensis (Huang Qin; HQ) and one of its main components baicalin enhanced 5-fluorouracil (5-FU) antitumor activity against CRC. Cell proliferation assays, cell cycle analysis, reverse-phase protein array (RPPA) analysis, immunoblot analysis, and qRT-PCR were performed to investigate the mechanism(s) of action of HQ and its active components on growth of CRC cells. HQ exhibited in vitro antiproliferative activity against drug resistant human CRC cells, against human and mouse CRC cells with different genetic backgrounds and normal human colon epithelial cells. In vivo animal models were used to document the antitumor activity of HQ and baicalin. The mechanism of growth inhibitory activity of HQ is due to inhibition of proliferative signaling pathways including the CDK-RB pathway. In addition, HQ enhanced the antitumor effects of 5-FU and capecitabine in vivo. Furthermore, we identified baicalin as an active component of HQ. The combination of baicalin and 5-FU demonstrated synergistic activity against 5-FU-resistant RKO-R10 cells. The combination significantly inhibited in vivo tumor growth greater than each treatment alone. RPPA results showed that the signaling pathway alterations in CRC cells were similar following HQ and baicalin treatment. Together, these results indicate that HQ and its component baicalin enhance the effect of 5-fluorouracil-based chemotherapy via inhibition of CDK-RB pathway. These findings may provide the rational basis for developing agents that can overcome the development of cellular drug resistance
CIB1 is a regulator of pathological cardiac hypertrophy
Hypertrophic heart disease is a leading health problem facing the Western world. Here we identified the small EF-hand domain-containing protein CIB1 (Ca2+ and integrin binding protein 1) in a screen for novel regulators of cardiomyocyte hypertrophy. Yeast two-hybrid screening for CIB1 interacting partners identified a related EF-hand domain-containing protein calcineurin B, the regulatory subunit of the pro-hypertrophic protein phosphatase calcineurin. CIB1 largely localizes to the sarcolemma in mouse and human myocardium, where it anchors calcineurin to control its activation in coordination with the L-type Ca2+ channel. CIB1 protein levels and membrane association were enhanced in cardiac pathological hypertrophy, but not in physiological hypertrophy. Consistent with these observations, mice lacking Cib1 show a dramatic reduction in myocardial hypertrophy, fibrosis, cardiac dysfunction, and calcineurin-NFAT activity following pressure overload, while the degree of physiologic hypertrophy after swimming was not altered. Transgenic mice with inducible and cardiac-specific overexpression of CIB1 showed enhanced cardiac hypertrophy in response to pressure overload or calcineurin signaling. Moreover, mice lacking the Ppp3cb gene showed no enhancement in cardiac hypertrophy associated with CIB1 overexpression. Thus, CIB1 functions as a novel regulator of cardiac hypertrophy through its ability to regulate calcineurin sarcolemmal association and activation
Designed Single-Step Synthesis, Structure, and Derivative Textural Properties of Well-Ordered Layered Penta-coordinate Silicon Alcoholate Complexes
The controllable synthesis of well-ordered layered materials with specific nanoarchitecture poses a grand challenge in materials chemistry. Here the solvothermal synthesis of two structurally analogous 5-coordinate organosilicate complexes through a novel transesterification mechanism is reported. Since the polycrystalline nature of the intrinsic hypervalent Si complex thwarts the endeavor in determining its structure, a novel strategy concerning the elegant addition of a small fraction of B species as an effective crystal growth mediator and a sacrificial agent is proposed to directly prepare diffraction-quality single crystals without disrupting the intrinsic elemental type. In the determined crystal structure, two monomeric primary building units (PBUs) self-assemble into a dimeric asymmetric secondary BU via strong Na+[BOND]O2− ionic bonds. The designed one-pot synthesis is straightforward, robust, and efficient, leading to a well-ordered (10ī)-parallel layered Si complex with its principal interlayers intercalated with extensive van der Waals gaps in spite of the presence of substantial Na+ counter-ions as a result of unique atomic arrangement in its structure. However, upon fast pyrolysis, followed by acid leaching, both complexes are converted into two SiO2 composites bearing BET surface areas of 163.3 and 254.7 m2 g−1 for the pyrolyzed intrinsic and B-assisted Si complexes, respectively. The transesterification methodology merely involving alcoholysis but without any hydrolysis side reaction is designed to have generalized applicability for use in synthesizing new layered metal–organic compounds with tailored PBUs and corresponding metal oxide particles with hierarchical porosity.United States. Defense Advanced Research Projects Agency (control No. 0471-1627)National Institute for Biomedical Imaging and Bioengineering (U.S.) (award No. EB-001960)National Institutes of Health (U.S.) (NIBIB award No. EB-002026)National Science Foundation (U.S.) (Grant No. CHE-0946721
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