101 research outputs found

    Rifampicin Does not Significantly Affect the Expression of Small Heterodimer Partner in Primary Human Hepatocytes

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    The small/short heterodimer partner (SHP, NR0B2) is a nuclear receptor corepressor lacking a DNA binding domain. SHP is induced by bile acid-activated farnesoid X receptor (FXR) resulting in CYP7A1 gene suppression. In contrast, Pregnane X receptor (PXR) activation by its ligands was recently suggested to inhibit SHP gene transactivation to maximize the induction of PXR target genes. However, there are also conflicting reports in literature whether PXR or rodent Pxr activation down-regulates SHP/Shp expression. Moreover, the PXR-mediated regulation of the SHP gene has been studied only at the SHP mRNA and transactivation (gene reporter assay) levels. In this study, we studied the effect of rifampicin, a prototype PXR ligand, on SHP mRNA, and protein expression in three primary human hepatocyte cultures. We found that SHP mRNA is not systematically down-regulated in hepatocyte in culture after 24 h treatment with rifampicin. Consistently, we did not observe down-regulation of SHP protein in primary human hepatocytes after 24 and 48 h of incubation with rifampicin. We can conclude that although we observed slight down-regulation of SHP mRNA and protein in several hepatocyte preparations, the phenomenon is unlikely critical for PXR-mediated induction of its target genes

    Present knowledge of distribution of Tandonia budapestensis (Hazay, 1881) in the Czech and Slovak Republics (Gastropoda: Milacidae)

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    All published and known unpublished data on Tandonia budapestensis (Hazay, 1881) from the territory of the Czech and Slovak Republics are summarised. This species occurs rarely in both states in altitudes up to ca. 420 m. and is closely bound to anthropogenous habitats

    Mixed germ cell sex cord-stromal tumors of the testis and ovary. Morphological, immunohistochemical, and molecular genetic study of seven cases

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    We present the morphological, immunohistochemical, and molecular genetic features of three cases of testicular and four cases of ovarian mixed germ cell sex cord-stromal tumors (MGSCT). The germ cells in the testicular MGSCTs morphologically differed from those in classical seminomas by lacking the typical square off quality of the nuclei. In contrast to the nuclei in classical seminomas, their size in testicular MGSCTs was smaller and nucleoli were inconspicuous and the cytoplasm was Periodic Acid-Schiff(PAS) negative. Quite on the contrary, the variability in the size of the nuclei of the germ cells in the testicular MGSCTs was more similar to that seen in the germ cells of spermatocytic seminomas. Immunohisto-chemically, the germ cells of MGSCTs in one case reacted positively with antibody to AE1-AE3 by paranuclear dotlike or rodlike positivity. All three testicular MGSCTs had a negative reaction with the rest of antibodies, including placental alkaline phosphatase (PLAP), OCT4, and c-kit protein. Ovarian MGSCT in our series differed from the testicular lesions in both the germ cell component and the sex cord component. The germ cells in all four ovarian cases had cytomorphological and immuno-histochemical features identical to those in classical seminomas/dysgerminomas. They possessed the typical square off quality of the nuclei, which were much more blastic, with more mitoses compared with the testicular tumors in our series, and they were PLAP (4/4), OCT4 (4/4) and c-kit protein (3/4) positive immunohisto-chemically. The cytoplasm of the germ cells in ovarian neoplasms contained PAS positive glycogen. Germ cells in one ovarian MGSCTs showed amplification of l2p. All other germ cells were negative for amplification of 12p. All five successfully analyzed cases showed no mutation in all studied exons and exon-intron junctions in c-kit and PDFGRA genes

    Successful Peripheral Blood Stem Cells Collection in Imatinib Pretreated and Nilotinib-Treated Chronic Myeloid Leukemia Patient

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    We report a case of a successful mobilization and harvest of the peripheral blood stem cells (PBSCs) in imatinib-pretreated and nilotinib treated 52-year-old woman diagnosed with Philadelphia chromosome-positive and BCR-ABL (b2a2) positive chronic phase CML in 2/2002. She failed interferon-alfa and imatinib treatment. She achieved her first complete molecular remission after 16 months of nilotinib treatment and later on was mobilized with filgrastim at a dose of 10 ug/kg/day applied subcutaneously once daily. The total number of 2.98 × 106 CD34+ cells/kg was harvested on the fourth day of the mobilization. The autologous graft of the stem cells was cryopreserved and tested for the residual disease: the FISH revealed negative results and the RT-PCR was positive (BCR-ABL/ABL ratio 0,0017 in RQ-PCR). To our knowledge, this is the first report of successful PBSC harvest in a patient significantly pretreated with imatinib and nilotinib

    Screening ethnically diverse human embryonic stem cells identifies a chromosome 20 minimal amplicon conferring growth advantage

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    The International Stem Cell Initiative analyzed 125 human embryonic stem (ES) cell lines and 11 induced pluripotent stem (iPS) cell lines, from 38 laboratories worldwide, for genetic changes occurring during culture. Most lines were analyzed at an early and late passage. Single-nucleotide polymorphism (SNP) analysis revealed that they included representatives of most major ethnic groups. Most lines remained karyotypically normal, but there was a progressive tendency to acquire changes on prolonged culture, commonly affecting chromosomes 1, 12, 17 and 20. DNA methylation patterns changed haphazardly with no link to time in culture. Structural variants, determined from the SNP arrays, also appeared sporadically. No common variants related to culture were observed on chromosomes 1, 12 and 17, but a minimal amplicon in chromosome 20q11.21, including three genes expressed in human ES cells, ID1, BCL2L1 and HM13, occurred in >20% of the lines. Of these genes, BCL2L1 is a strong candidate for driving culture adaptation of ES cells

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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    JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

    Detection of the Diffuse Supernova Neutrino Background with JUNO

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    As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
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