538 research outputs found

    Senescence and immortality in hepatocellular carcinoma

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    Cataloged from PDF version of article.Cellular senescence is a process leading to terminal growth arrest with characteristic morphological features. This process is mediated by telomere-dependent, oncogene-induced and ROS-induced pathways, but persistent DNA damage is the most common cause. Senescence arrest is mediated by p16(INK4a)- and p21(Cip1)-dependent pathways both leading to retinoblastoma protein (pRb) activation. p53 plays a relay role between DNA damage sensing and p21(Cip1) activation. pRb arrests the cell cycle by recruiting proliferation genes to facultative heterochromatin for permanent silencing. Replicative senescence that occurs in hepatocytes in culture and in liver cirrhosis is associated with lack of telomerase activity and results in telomere shortening. Hepatocellular carcinoma (HCC) cells display inactivating mutations of p53 and epigenetic silencing of p16(INK4a). Moreover, they re-express telomerase reverse transcriptase required for telomere maintenance. Thus, senescence bypass and cellular immortality is likely to contribute significantly to HCC development. Oncogene-induced senescence in premalignant lesions and reversible immortality of cancer cells including HCC offer new potentials for tumor prevention and treatment. (C) 2008 Elsevier Ireland Ltd. All rights reserved

    The Progress of Poultry Meat Production in Turkey

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    Concurrent acute pancreatitis and pericardial effusion

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    While pleural effusion and ascites secondary to acute pancreatitis are common, clinically relevant pericardial effusion and cardiac tamponade are observed rarely. In a study by Pezzilli et al., pleural effusion was noted in 7 of the 21 patients with acute pancreatitis whereas the authors detected pericardial effusion development in only three. The authors asserted that pleural effusion was associated with severe acute pancreatitis, while pericardial effusion and the severity of acute pancreatitis were not significantly related

    Konwencjonalna i płynna cytologia – badania porównawcze

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    Objectives: The aim of our study is the comparison of the results of conventional smear (CC) technique and liquidbased cytology (LBC) technique used as cervical cancer screening methods. Material and methods: The results of 47954 patients submitted to smear screening in our gynecology clinic between January 2008 and December 2014 have been studied. The smear results have been divided into two groups CC and LBC according to the technique used. Results: When considering the distribution within CC group, the results were as follows: intraepithelial cell abnormalities 2,0% (n=619), insufficient sample for analysis 2,1% (n=660), Atypical squamous cells of undetermined significance (ASC-US) 1.8% (n=554), Low grade squamous intraepithelial lesion (LGSIL) 0.1% (n=35), High grade squamous intraepithelial lesion (HGSIL) 0.1% (n=16), Atypical squamous cells – cannot exclude HGSIL (ASC-H) 0.029% (n=9), Atypical glandular cells- not other wise specified (AGC-NOS) 0.012% (n=4), squamous carcinoma 0.003% (n=1). When considering the distribution in LBC group, the results were as follows: intraepithelial cell abnormalities2.1% (n=357), insufficient sample for analysis 0.9% (n=144), ASC-US 1.8% (n=296), LGSIL 0.2% (n=38), HGSIL 0.1% (n=8), ASC-H 0.1% (n=10), AGC-NOS 0.017% (n=3), squamous carcinoma 0.011% (n=2). Conclusions: Although the rates of epithelial cell abnormalities are similar for both tests, LSIL results are more frequently observed in LBC technique. In LBC technique, the number of insufficient sample for analysis is quite low compared to CC group and thus constitutes an advantage.  Cel pracy: Celem badania było porównanie wyników konwencjonalnej (CC) i płynnej cytologii (LBC) stosowanej w skriningu raka szyjki macicy. Materiał i metoda: Przeanalizowano wyniki od 47954 pacjentek objętych cytologicznym badaniem skriningowym w naszym oddziale ginekologicznym w okresie od stycznia 2008 do grudnia 2014. Wyniki cytologiczne podzielono na dwie grupy CC i LBC w zależności od techniki pobierania. Wyniki: W grupie CC wyniki przedstawiały się nastepująco: nieprawidłowości komórek śródnabłonkowych 2,0% (n=619), nieodpowiednia próbka do analizy 2,1% (n=660), ASC-US 1.8% (n=554), LGSIL 0.1% (n=35), HGSIL 0.1% (n=16), ASC-H 0.029% (n=9), AGC-NOS 0.012% (n=4), rak płaskonabłonkowy 0.003% (n=1). W grupie LBC wyniki przedstawiały się następująco: nieprawidłowości komórek śródnabłonkowych 2.1% (n=357), nieodpowiednia próbka do analizy 0.9% (n=144), ASC-US 1.8% (n=296), LGSIL 0.2% (n=38), HGSIL 0.1% (n=8), ASC-H 0.1% (n=10), AGC-NOS 0.017% (n=3), rak płaskonabłonkowy 0.011% (n=2). Wnioski: Chociaż odsetek nieprawidłowości komórek śródnabłonkowych jest podobny dla obu testów, wyniki LSIL są częściej obserwowane w technice LBC. W metodzie LBC liczba próbek nieodpowiednich do analizy jest dość niska w porównaniu do grupy CC, stąd jest to jej niewątpliwa zaleta.

    Simultaneous preconcentration of trace metals in environmental samples using amberlite XAD-2010/8-hydroxyquinoline system

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    A simple and sensitive system for simultaneous preconcentration of Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Pb(II) and Cd(II) at trace level by flame atomic absorption spectrometry (FAAS) is proposed. Amberlite XAD-2010 packed in a column was used as sorbent. Analyte ions were sorbed in the column as their 8-hydroxyquinoline chelates; they could then be eluted by 1 mol L -1 HNO3 in acetone. The analytical conditions including pH, amounts of 8-hydroxyquinoline, sample volume etc. on the quantitative recoveries of the analytes were investigated. The effects of the concomitants ions on the recoveries of the analytes column were also studied. The detection limits, corresponding to three times the standard deviation of the blank, were found to be in the range of 0.10-0.40 ÎĽg L-1. The accuracy of the procedure was measured by analyte determinations in certified reference materials (CRM NIES No. 7 Tea Leaves and TMDW-500 Drinking Water). The applications of the presented system were performed by the analysis of some environmental samples including water samples

    Abnormal ECG Findings in Athletes: Clinical Evaluation and Considerations.

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    PURPOSE OF REVIEW: Pre-participation cardiovascular evaluation with electrocardiography is normal practice for most sporting bodies. Awareness about sudden cardiac death in athletes and recognizing how screening can help identify vulnerable athletes have empowered different sporting disciplines to invest in the wellbeing of their athletes. RECENT FINDINGS: Discerning physiological electrical alterations due to athletic training from those representing cardiac pathology may be challenging. The mode of investigation of affected athletes is dependent on the electrical anomaly and the disease(s) in question. This review will highlight specific pathological ECG patterns that warrant assessment and surveillance, together with an in-depth review of the recommended algorithm for evaluation

    VERITAS Search for VHE Gamma-ray Emission from Dwarf Spheroidal Galaxies

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    Indirect dark matter searches with ground-based gamma-ray observatories provide an alternative for identifying the particle nature of dark matter that is complementary to that of direct search or accelerator production experiments. We present the results of observations of the dwarf spheroidal galaxies Draco, Ursa Minor, Bootes 1, and Willman 1 conducted by VERITAS. These galaxies are nearby dark matter dominated objects located at a typical distance of several tens of kiloparsecs for which there are good measurements of the dark matter density profile from stellar velocity measurements. Since the conventional astrophysical background of very high energy gamma rays from these objects appears to be negligible, they are good targets to search for the secondary gamma-ray photons produced by interacting or decaying dark matter particles. No significant gamma-ray flux above 200 GeV was detected from these four dwarf galaxies for a typical exposure of ~20 hours. The 95% confidence upper limits on the integral gamma-ray flux are in the range 0.4-2.2x10^-12 photons cm^-2s^-1. We interpret this limiting flux in the context of pair annihilation of weakly interacting massive particles and derive constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the WIMPs. The limits are obtained under conservative assumptions regarding the dark matter distribution in dwarf galaxies and are approximately three orders of magnitude above the generic theoretical prediction for WIMPs in the minimal supersymmetric standard model framework. However significant uncertainty exists in the dark matter distribution as well as the neutralino cross sections which under favorable assumptions could further lower the limits.Comment: 21 pages, 2 figures, updated to reflect version published in ApJ. NOTE: M.D. Wood added as autho

    Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on its redshift

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    We report the first detection of very-high-energy (VHE) gamma-ray emission above 140 GeV from PKS 1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140 GeV measured by VERITAS is well described by a power law with a photon index of 3.8 +- 0.5_stat +- 0.3_syst and a flux normalization at 200 GeV of (5.1 +- 0.9_stat +- 0.5_syst) x 10^{-11} TeV^-1 cm^-2 s^-1, where stat and syst denote the statistical and systematical uncertainty, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high energy observations with the Fermi Large Area Telescope (LAT). Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution (SED) is well described by a one-zone synchrotron self-Compton (SSC) model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light (EBL) absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.Comment: accepted for publication, Ap
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