27 research outputs found

    Hedgehog Promotes Neovascularization in Pancreatic Cancers by Regulating Ang-1 and IGF-1 Expression in Bone-Marrow Derived Pro-Angiogenic Cells

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    http://creativecommons.org/licenses/by/2.0/ PublisherBackground: The hedgehog (Hh) pathway has been implicated in the pathogenesis of cancer including pancreatic ductal adenocarcinoma (PDAC). Recent studies have suggested that the oncogenic function of Hh in PDAC involves signaling in the stromal cells rather than cell autonomous effects on the tumor cells. However, the origin and nature of the stromal cell type(s) that are responsive to Hh signaling remained unknown. Since Hh signaling plays a crucial role during embryonic and postnatal vasculogenesis, we speculated that Hh ligand may act on tumor vasculature specifically focusing on bone marrow (BM)-derived cells. Methodology/Principal Findings: Cyclopamine was utilized to inhibit the Hh pathway in human PDAC cell lines and their xenografts. BM transplants, co-culture systems of tumor cells and BM-derived pro-angiogenic cells (BMPCs) were employed to assess the role of tumor-derived Hh in regulating the BM compartment and the contribution of BM-derived cells to angiogenesis in PDAC. Cyclopamine administration attenuated Hh signaling in the stroma rather than in the cancer cells as reflected by decreased expression of full length Gli2 protein and Gli1 mRNA specifically in the compartment. Cyclopamine inhibited the growth of PDAC xenografts in association with regression of the tumor vasculature and reduced homing of BM-derived cells to the tumor. Host-derived Ang-1 and IGF-1 mRNA levels were downregulated by cyclopamine in the tumor xenografts. In vitro co-culture and matrigel plug assays demonstrated that PDAC cell-derived Shh induced Ang-1 and IGF-1 production in BMPCs, resulting in their enhanced migration and capillary morphogenesis activity. Conclusions/Significance: We identified the BMPCs as alternative stromal targets of Hh-ligand in PDAC suggesting that the tumor vasculature is an attractive therapeutic target of Hh blockade. Our data is consistent with the emerging concept that BM-derived cells make important contributions to epithelial tumorigenesis

    Coincidence analysis to search for inspiraling compact binaries using TAMA300 and LISM data

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    Japanese laser interferometric gravitational wave detectors, TAMA300 and LISM, performed a coincident observation during 2001. We perform a coincidence analysis to search for inspiraling compact binaries. The length of data used for the coincidence analysis is 275 hours when both TAMA300 and LISM detectors are operated simultaneously. TAMA300 and LISM data are analyzed by matched filtering, and candidates for gravitational wave events are obtained. If there is a true gravitational wave signal, it should appear in both data of detectors with consistent waveforms characterized by masses of stars, amplitude of the signal, the coalescence time and so on. We introduce a set of coincidence conditions of the parameters, and search for coincident events. This procedure reduces the number of fake events considerably, by a factor 104\sim 10^{-4} compared with the number of fake events in single detector analysis. We find that the number of events after imposing the coincidence conditions is consistent with the number of accidental coincidences produced purely by noise. We thus find no evidence of gravitational wave signals. We obtain an upper limit of 0.046 /hours (CL =90= 90 %) to the Galactic event rate within 1kpc from the Earth. The method used in this paper can be applied straightforwardly to the case of coincidence observations with more than two detectors with arbitrary arm directions.Comment: 28 pages, 17 figures, Replaced with the version to be published in Physical Review

    Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004

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    We analyze the data of TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtained a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effect of various systematic errors such like the uncertainty of the background estimation and the calibration of the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was correcte

    Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses

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    We present data-analysis schemes and results of observations with the TAMA300 gravitational-wave detector, targeting burst signals from stellar-core collapse events. In analyses for burst gravitational waves, the detection and fake-reduction schemes are different from well-investigated ones for a chirp-wave analysis, because precise waveform templates are not available. We used an excess-power filter for the extraction of gravitational-wave candidates, and developed two methods for the reduction of fake events caused by non-stationary noises of the detector. These analysis schemes were applied to real data from the TAMA300 interferometric gravitational wave detector. As a result, fake events were reduced by a factor of about 1000 in the best cases. The resultant event candidates were interpreted from an astronomical viewpoint. We set an upper limit of 2.2x10^3 events/sec on the burst gravitational-wave event rate in our Galaxy with a confidence level of 90%. This work sets a milestone and prospects on the search for burst gravitational waves, by establishing an analysis scheme for the observation data from an interferometric gravitational wave detector

    Stable Operation of a 300-m Laser Interferometer with Sufficient Sensitivity to Detect Gravitational-Wave Events within our Galaxy

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    TAMA300, an interferometric gravitational-wave detector with 300-m baseline length, has been developed and operated with sufficient sensitivity to detect gravitational-wave events within our galaxy and sufficient stability for observations; the interferometer was operated for over 10 hours stably and continuously. With a strain-equivalent noise level of h5×1021/Hzh\sim 5 \times 10^{-21} /\sqrt{\rm Hz}, a signal-to-noise ratio (SNR) of 30 is expected for gravitational waves generated by a coalescence of 1.4 MM_\odot-1.4 MM_\odot binary neutron stars at 10 kpc distance. %In addition, almost all noise sources which limit the sensitivity and which %disturb the stable operation have been identified. We evaluated the stability of the detector sensitivity with a 2-week data-taking run, collecting 160 hours of data to be analyzed in the search for gravitational waves.Comment: 5 pages, 4 figure

    How Far Can We Go with Laparoscopic Liver Resection for Hepatocellular Carcinoma? Laparoscopic Sectionectomy of the Liver Combined with the Resection of the Major Hepatic Vein Main Trunk

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    Although the reports of laparoscopic major liver resection are increasing, hepatocellular carcinomas (HCCs) close to the liver hilum and/or major hepatic veins are still considered contraindications. There is virtually no report of laparoscopic liver resection (LLR) for HCC which involves the main trunk of major hepatic veins. We present our method for the procedure. We experienced 6 cases: 3 right anterior, 2 left medial, and 1 right posterior extended sectionectomies with major hepatic vein resection; tumor sizes are within 40–75 (median: 60) mm. The operating time, intraoperative blood loss, and postoperative hospital stay are within 341–603 (median: 434) min, 100–750 (300) ml, and 8–44 (18) days. There was no mortality and 1 patient developed postoperative pleural effusion. For these procedures, we propose that the steps listed below are useful, taking advantages of the laparoscopy-specific view. (1) The Glissonian pedicle of the section is encircled and clamped. (2) Liver transection on the ischemic line is performed in the caudal to cranial direction. (3) During transection, the clamped Glissonian pedicle and the peripheral part of hepatic vein are divided. (4) The root of hepatic vein is divided in the good view from caudal and dorsal direction

    Transumbilical single-incision laparoscopic appendectomy with extracorporeal hand-sewn stump closure in adult patients

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    OBJECTIVES: We evaluated the clinical outcomes of transumbilical single-incision laparoscopic appendectomy with extracorporeal hand-sewn stump closure in adults. METHODS: One-hundred-and-thirty-one consecutive adults with acute appendicitis were treated with the intention of performing transumbilical single-incision laparoscopic appendectomy with extracorporeal hand-sewn stump closure from July 2012 to December 2017. The procedure completion rate and outcomes were examined. To evaluate the risk factors for conversion, the background data were compared between the patients in whom the procedure was completed versus those in whom the procedure was uncompleted. RESULTS: The procedure was completed in 113 of 131 patients (86.3%). Single-site surgery was completed in 117 patients (89.3%). The median operation time was 79 (range 30–270) minutes and median intraoperative blood loss was 10 (range 0–394) ml. Postoperative complications occurred in 17 patients (13.0%). Postoperative hospital stay was 6 (range 1–27) days. The 18 patients in whom the procedure could not be completed comprised four patients in whom the stapler was used for intraabdominal stump closure, and 14 patients who were converted to multiport laparoscopic surgery or open surgery. Multivariate analysis showed that the independent risk factors for conversion were age, preoperative abscess, and peri-appendiceal fat density. Receiver operating characteristic curve analysis showed that the cutoff value of peri-appendiceal fat density for conversion was –40.51 Hounsfield units. CONCLUSIONS: Transumbilical single-incision laparoscopic appendectomy with extracorporeal hand-sewn stump closure was safe in adults with acute appendicitis. The risk factors for conversion were age ≥60 years, preoperative abscess, and peri-appendiceal fat density ≥–40.51 Hounsfield units
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