196 results on '"D. Popp"'
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2. Genotoxic Bystander Signals from Irradiated Human Mesenchymal Stromal Cells Mainly Localize in the 10–100 kDa Fraction of Conditioned Medium
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Vanessa Kohl, Alice Fabarius, Oliver Drews, Miriam Bierbaum, Ahmed Jawhar, Ali Darwich, Christel Weiss, Johanna Flach, Susanne Brendel, Helga Kleiner, Wolfgang Seifarth, Wolf-Karsten Hofmann, and Henning D. Popp
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bystander signals ,radiation-induced bystander effects ,mesenchymal stromal cells ,CD34+ cells ,leukemia ,Cytology ,QH573-671 - Abstract
Genotoxic bystander signals released from irradiated human mesenchymal stromal cells (MSC) may induce radiation-induced bystander effects (RIBEs) in human hematopoietic stem and progenitor cells (HSPC), potentially causing leukemic transformation. Although the source of bystander signals is evident, the identification and characterization of these signals is challenging. Here, RIBEs were analyzed in human CD34+ cells cultured in distinct molecular size fractions of medium, conditioned by 2 Gy irradiated human MSC. Specifically, γH2AX foci (as a marker of DNA double-strand breaks) and chromosomal instability were evaluated in CD34+ cells grown in approximate (I) < 10 kDa, (II) 10–100 kDa and (III) > 100 kDa fractions of MSC conditioned medium and un-/fractionated control medium, respectively. Hitherto, significantly increased numbers of γH2AX foci (p = 0.0286) and aberrant metaphases (p = 0.0022) were detected in CD34+ cells grown in the (II) 10–100 kDa fraction (0.67 ± 0.10 γH2AX foci per CD34+ cell ∨ 3.8 ± 0.3 aberrant metaphases per CD34+ cell sample; mean ± SEM) when compared to (I) < 10 kDa (0.19 ± 0.01 ∨ 0.3 ± 0.2) or (III) > 100 kDa fractions (0.23 ± 0.04 ∨ 0.4 ± 0.4) or un-/fractionated control medium (0.12 ± 0.01 ∨ 0.1 ± 0.1). Furthermore, RIBEs disappeared after heat inactivation of medium at 75 °C. Taken together, our data suggest that RIBEs are mainly mediated by the heat-sensitive (II) 10–100 kDa fraction of MSC conditioned medium. We postulate proteins as RIBE mediators and in-depth proteome analyses to identify key bystander signals, which define targets for the development of next-generation anti-leukemic drugs.
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- 2021
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3. Early application of kinetic theory of gases to star clusters
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Bruce D. Popp
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Physics and Astronomy (miscellaneous) ,Arts and Humanities (miscellaneous) ,Astronomy and Astrophysics - Abstract
This is a case of working by analogy to apply successful work from one field, the kinetic theory of gases, to another field, the distribution of stars in globular clusters. The origin of the analogy lies in Henri Poincaré reading a vague suggestion by Lord Kelvin and recognizing the interest and potential value of this suggestion. The result is the application of mechanics to the dynamics of clusters with very many stars. A good idea, even a very clever good idea, still takes significant work to elaborate in all its implications. Here we see assumptions that lead to partial success in providing a relation between the density of stars in a cluster and the distance from the center. Partial success motivated work using assumptions that were less restrictive. We follow the assumptions and work through 1916, when work paused for many years.
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- 2022
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4. Leukocyte DNA damage after reduced and conventional absorbed radiation doses using 3rd generation dual-source CT technology
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Henning D. Popp, Mathias Meyer, Susanne Brendel, Wiltrud Prinzhorn, Nicole Naumann, Christel Weiss, Wolfgang Seifarth, Stefan O. Schoenberg, Wolf-K. Hofmann, Thomas Henzler, and Alice Fabarius
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Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Purpose: Computed tomography (CT) scans are an important source of ionizing irradiation (IR) in medicine that can induce a variety of DNA damage in human tissues. With technological improvements CT scans at reduced absorbed doses became feasible presumably lowering genotoxic side effects. Materials and methods: For measuring DNA damage we performed γH2AX foci microscopy in peripheral blood mononuclear cells (PBMC) after exposure to reduced and conventional absorbed radiation doses using 3rd generation dual-source CT (DSCT) technology. Results: CT scans performed at reduced absorbed doses of 3 mGy induced significant lower levels (p
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- 2016
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5. Real time digital signal strength tracking for RF source location.
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J. D. Popp and J. Lopez
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- 2015
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6. Spektrale Metallartefakt-Reduktion an Photon-Counting Detektor CT-Datensätzen am Beispiel von Spondylodesematerial
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D Popp, X A Sinzinger, A J Decker, S Bette, F Braun, K Rippel, C Wollny, C Scheurig-Münkler, J T Kröncke, and F Schwarz
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- 2022
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7. Evidence for recombinant GRP78, CALR, PDIA3 and GPI as mediators of genetic instability in human CD34+ cells
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Alice Fabarius, Vanessa Samra, Oliver Drews, Handan Mörz, Miriam Bierbaum, Ali Darwich, Christel Weiss, Susanne Brendel, Helga Kleiner, Wolfgang Seifarth, Wolfgang Greffrath, Wolf-Karsten Hofmann, Clemens A. Schmitt, and Henning D. Popp
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Cancer Research ,Oncology ,ionizing irradiation ,mesenchymal stromal cells ,genotoxic signaling ,GRP78 ,CALR ,PDIA3 ,GPI ,CD34+ cells ,genetic instability - Abstract
Soluble factors released from irradiated human mesenchymal stromal cells (MSC) may induce genetic instability in human CD34+ cells, potentially mediating hematologic disorders. Recently, we identified four key proteins in the secretome of X-ray-irradiated MSC, among them three endoplasmic reticulum proteins, the 78 kDa glucose-related protein (GRP78), calreticulin (CALR), and protein disulfide-isomerase A3 (PDIA3), as well as the glycolytic enzyme glucose-6-phosphate isomerase (GPI). Here, we demonstrate that exposition of CD34+ cells to recombinant GRP78, CALR, PDIA3 and GPI induces substantial genetic instability. Increased numbers of γH2AX foci (p < 0.0001), centrosome anomalies (p = 0.1000) and aberrant metaphases (p = 0.0022) were detected in CD34+ cells upon incubation with these factors. Specifically, γH2AX foci were found to be induced 4–5-fold in response to any individual of the four factors, and centrosome anomalies by 3–4 fold compared to control medium, which contained none of the recombinant proteins. Aberrant metaphases, not seen in the context of control medium, were detected to a similar extent than centrosome anomalies across the four factors. Notably, the strongest effects were observed when all four factors were collectively provided. In summary, our data suggest that specific components of the secretome from irradiated MSC act as mediators of genetic instability in CD34+ cells, thereby possibly contributing to the pathogenesis of radiation-induced hematologic disorders beyond direct radiation-evoked DNA strand breaks.
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- 2022
8. Verizon Uses Advanced Analytics to Rationalize Its Tail Spend Suppliers
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Anne G. Robinson, Vedat Akgun, Sagar Shah, Timothy D . Popp, Hossein Abdollahnejadbarough, Eric Shroyer, Colin P . Golding, Kalyan S . Mupparaju, Yanai S . Golany, and Abelardo C . Leites
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Strategic sourcing ,021103 operations research ,Analytics ,business.industry ,Supply chain ,Business process outsourcing ,0502 economics and business ,05 social sciences ,0211 other engineering and technologies ,02 engineering and technology ,business ,050203 business & management ,Industrial organization - Abstract
The Verizon Global Supply Chain organization currently manages thousands of active supplier contracts. These contracts account for several billion dollars of annualized Verizon spend. Managing thousands of suppliers, controlling spend, and achieving the best price per unit (PPU) through negotiations are costly and labor-intensive tasks handled by Verizon strategic sourcing teams. Verizon engages thousands of suppliers for many reasons—best price, diversity, short-term requirements, and so forth. Whereas managing a few larger spend suppliers can be done manually by dedicated sourcing managers, managing thousands of smaller suppliers at the tail spend is challenging, can often introduce risk, and can be expensive. At Verizon, a unique blend of descriptive, predictive, and prescriptive analytics, as well as Verizon-specific sourcing acumen was leveraged to tackle this problem and rationalize Verizon’s tail spend suppliers. Through the creative application of operations research, machine learning, text mining, natural language processing, and artificial intelligence, Verizon reduced spend by millions of dollars and acquired the lowest PPU for the sourced products and services. Other benefits Verizon realized were centralized and transparent contract and supplier relationship management, overhead cost reduction, decreased contract execution lead time, and service quality improvement for Verizon’s strategic sourcing teams.
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- 2020
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9. Definition of factors associated with negative antibody response after COVID-19 vaccination in patients with hematological diseases
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Jil Rotterdam, Margot Thiaucourt, Christel Weiss, Juliana Schwaab, Andreas Reiter, Sebastian Kreil, Laurenz Steiner, Sebastian Fenchel, Henning D. Popp, Wolf-Karsten Hofmann, Karin Bonatz, Catharina Gerhards, Michael Neumaier, Stefan A. Klein, Sonika Rao, Mohamad Jawhar, and Susanne Saussele
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Male ,COVID-19 Vaccines ,Myeloproliferative Disorders ,SARS-CoV-2 ,Vaccination ,COVID-19 ,Hematology ,General Medicine ,Middle Aged ,Antibodies, Viral ,Hematologic Diseases ,Leukemia, Myelogenous, Chronic, BCR-ABL Positive ,Antibody Formation ,Spike Glycoprotein, Coronavirus ,Humans ,Female ,Treatment Failure ,BNT162 Vaccine - Abstract
COVID-19 in patients with hematological diseases is associated with a high mortality. Moreover, preventive vaccination demonstrated reduced efficacy and the knowledge on influencing factors is limited. In this single-center study, antibody levels of the SARS-CoV-2 spike protein were measured ≥ 2 weeks after 2nd COVID-19 vaccination with a concentration ≥ 0.8 U/mL considered positive. Between July and October 2021, in a total of 373 patients (median age 64 years, 44% women) with myeloid neoplasms (n = 214, 57%), lymphoid neoplasms (n = 124, n = 33%), and other diseases (n = 35, 10%), vaccination was performed with BNT162b2 (BioNTech), mRNA-1273 (Moderna), ChADOx1 (AstraZeneca), or a combination. A total of 229 patients (61%) were on active therapy within 3 months prior vaccination and 144 patients (39%) were previously treated or treatment naïve. Vaccination-related antibody response was negative in 56/373 patients (15%): in 39/124 patients with lymphoid neoplasms, 13/214 with myeloid neoplasms, and 4/35 with other diseases. Active treatment per se was not correlated with negative response. However, rituximab and BTK inhibitor treatment were correlated significantly with a negative vaccination response, whereas younger age and chronic myeloid leukemia (CML) disease were associated with positive response. In addition, 5 of 6 patients with myeloproliferative neoplasm (MPN) and negative vaccination response were on active treatment with ruxolitinib. In conclusion, a remarkable percentage of patients with hematological diseases had no response after 2nd COVID-19 vaccination. Multivariable analysis revealed important factors associated with response to vaccination. The results may serve as a guide for better protection and surveillance in this vulnerable patient cohort.
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- 2022
10. Proteins Marking the Sequence of Genotoxic Signaling from Irradiated Mesenchymal Stromal Cells to CD34+ Cells
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Vanessa Kohl, Alice Fabarius, Daniel Nowak, Birgit Spiess, Christel Weiss, Henning Roehl, Oliver Drews, Wolf-Karsten Hofmann, Henning D. Popp, Helga Kleiner, Susanne Brendel, Victor Costina, Johanna Flach, Miriam Bierbaum, Ahmed Jawhar, and Wolfgang Seifarth
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Male ,Proteomics ,Myeloid ,Proteome ,CD34 ,Antigens, CD34 ,PDIA3 ,Histones ,IQGAP1 ,Radiation, Ionizing ,Biology (General) ,Cytoskeleton ,Endoplasmic Reticulum Chaperone BiP ,Spectroscopy ,chemistry.chemical_classification ,irradiation ,Chemistry ,Cell Differentiation ,General Medicine ,CD34+ cells ,myeloid neoplasms ,Computer Science Applications ,Cell biology ,medicine.anatomical_structure ,Female ,mesenchymal stromal cells ,Intracellular ,Signal Transduction ,Cell Survival ,QH301-705.5 ,Bone Marrow Cells ,Models, Biological ,Catalysis ,Article ,Inorganic Chemistry ,non-targeted effects ,Chromosomal Instability ,medicine ,Humans ,Physical and Theoretical Chemistry ,Molecular Biology ,QD1-999 ,Aged ,Reactive oxygen species ,Organic Chemistry ,Mesenchymal stem cell ,Mesenchymal Stem Cells ,genotoxic signals ,Culture Media, Conditioned ,Reactive Oxygen Species ,Biomarkers ,DNA Damage - Abstract
Non-targeted effects (NTE) of ionizing radiation may initiate myeloid neoplasms (MN). Here, protein mediators (I) in irradiated human mesenchymal stromal cells (MSC) as the NTE source, (II) in MSC conditioned supernatant and (III) in human bone marrow CD34+ cells undergoing genotoxic NTE were investigated. Healthy sublethal irradiated MSC showed significantly increased levels of reactive oxygen species. These cells responded by increasing intracellular abundance of proteins involved in proteasomal degradation, protein translation, cytoskeleton dynamics, nucleocytoplasmic shuttling, and those with antioxidant activity. Among the increased proteins were THY1 and GNA11/14, which are signaling proteins with hitherto unknown functions in the radiation response and NTE. In the corresponding MSC conditioned medium, the three chaperones GRP78, CALR, and PDIA3 were increased. Together with GPI, these were the only four altered proteins, which were associated with the observed genotoxic NTE. Healthy CD34+ cells cultured in MSC conditioned medium suffered from more than a six-fold increase in γH2AX focal staining, indicative for DNA double-strand breaks, as well as numerical and structural chromosomal aberrations within three days. At this stage, five proteins were altered, among them IQGAP1, HMGB1, and PA2G4, which are involved in malign development. In summary, our data provide novel insights into three sequential steps of genotoxic signaling from irradiated MSC to CD34+ cells, implicating that induced NTE might initiate the development of MN.
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- 2021
11. Adverse prognostic impact of the kit d816v transcriptional activity in advanced systemic mastocytosis
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Wolf-Karsten Hofmann, Lukas Reiter, Sebastian Kreil, Thomas Kielsgaard Kristensen, Verena Haselmann, Oliver Hoffmann, Nicole Naumann, Peter Bugert, Sven Schneider, Nicholas C.P. Cross, Mohamad Jawhar, Juliana Schwaab, Georgia Metzgeroth, Sofie Baumann, Karl Sotlar, Alice Fabarius, Andreas Reiter, Christel Weiss, Johannes Lübke, Henning D. Popp, and Vito Dangelo
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Male ,0301 basic medicine ,Transcription, Genetic ,Survival ,Gastroenterology ,Allele burden ,lcsh:Chemistry ,0302 clinical medicine ,Gene Frequency ,Bone Marrow ,Medicine ,Systemic mastocytosis ,lcsh:QH301-705.5 ,Spectroscopy ,Aged, 80 and over ,advanced SM ,General Medicine ,Middle Aged ,Prognosis ,Pathophysiology ,Computer Science Applications ,Kit d816v ,Proto-Oncogene Proteins c-kit ,Phenotype ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Cohort ,Female ,KIT D816V ,Adult ,allele burden ,medicine.medical_specialty ,survival ,Article ,Catalysis ,Inorganic Chemistry ,03 medical and health sciences ,Mastocytosis, Systemic ,Internal medicine ,Humans ,Physical and Theoretical Chemistry ,Allele ,Molecular Biology ,Aged ,Advanced SM ,Transcriptional activity ,Receiver operating characteristic ,business.industry ,Organic Chemistry ,variant allele frequency ,DNA ,medicine.disease ,030104 developmental biology ,Amino Acid Substitution ,lcsh:Biology (General) ,lcsh:QD1-999 ,Mutation ,RNA ,Bone marrow ,business ,Variant allele frequency - Abstract
In systemic mastocytosis (SM), qualitative and serial quantitative assessment of the KIT D816V mutation is of diagnostic and prognostic relevance. We investigated peripheral blood and bone marrow samples of 161 patients (indolent SM (ISM), n = 40, advanced SM, AdvSM, n = 121) at referral and during follow-up for the KIT D816V variant allele frequency (VAF) at the DNA-level and the KIT D816V expressed allele burden (EAB) at the RNA-level. A round robin test with four participating laboratories revealed an excellent correlation (r >, 0.99, R2 >, 0.98) between three different DNA-assays. VAF and EAB strongly correlated in ISM (r = 0.91, coefficient of determination, R2 = 0.84) but only to a lesser extent in AdvSM (r = 0.71, R2 = 0.5). However, as compared to an EAB/VAF ratio ≤2 (cohort A, 77/121 patients, 64%) receiver operating characteristic (ROC) analysis identified an EAB/VAF ratio of >, 2 (cohort B, 44/121 patients, 36%) as predictive for an advanced phenotype and a significantly inferior median survival (3.3 vs. 11.7 years, p = 0.005). In terms of overall survival, Cox-regression analysis was only significant for the EAB/VAF ratio >, 2 (p = 0.006) but not for VAF or EAB individually. This study demonstrates for the first time that the transcriptional activity of KIT D816V may play an important role in the pathophysiology of SM.
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- 2021
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12. Genotoxic bystander signals from irradiated human mesenchymal stromal cells mainly localize in the 10 – 100 kDa fraction of conditioned medium
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Ahmed Jawhar, Wolfgang Seifarth, Miriam Bierbaum, Henning D. Popp, Alice Fabarius, Helga Kleiner, Christel Weiss, Wolf-Karsten Hofmann, Oliver Drews, Susanne Brendel, Vanessa Kohl, Ali Darwich, and Johanna Flach
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Chemistry ,Mesenchymal stem cell ,Conditioned medium ,Bystander effect ,Fraction (chemistry) ,Irradiation ,Cell biology - Published
- 2020
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13. Irradiated mesenchymal stromal cells induce genetic instability in human CD34+ cells
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Birgit Spiess, Alice Fabarius, Wolf-Karsten Hofmann, Ahmed Jawhar, Miriam Bierbaum, Wolfgang Seifarth, Helga Kleiner, Victor Costina, Susanne Brendel, Vanessa Kohl, Oliver Drews, Johanna Flach, Daniel Nowak, Henning D. Popp, Christel Weiss, and Henning Roehl
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Haematopoiesis ,Myeloid ,medicine.anatomical_structure ,Chemistry ,DNA damage ,Chromosome instability ,Mesenchymal stem cell ,Bystander effect ,CD34 ,medicine ,Progenitor cell ,Cell biology - Abstract
Radiation-induced bystander effects (RIBE) in human hematopoietic stem and progenitor cells may initiate myeloid neoplasms (MN). Here, the occurrence of RIBE caused by genotoxic signaling from irradiated human mesenchymal stromal cells (MSC) on human bone marrow CD34+ cells was investigated. For this purpose, healthy MSC were irradiated in order to generate conditioned medium containing potential genotoxic signaling factors. Afterwards, healthy CD34+ cells from the same donors were grown in conditioned medium and RIBE were analyzed. Increased DNA damage and chromosomal instability were detected in CD34+ cells grown in MSC conditioned medium when compared to CD34+ cells grown in control medium. Furthermore, reactive oxygen species and distinct proteome alterations, e.g., heat-shock protein GRP78, that might be secreted into the extracellular medium, were identified as potential RIBE mediators. In summary, our data provide evidence that irradiated MSC induce genetic instability in human CD34+ cells potentially resulting in the initiation of MN. Furthermore, the identification of key bystander signals, such as GRP78, may lay the framework for the development of next-generation anti-leukemic drugs.
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- 2020
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14. DNA Damage and DNA Damage Response in Chronic Myeloid Leukemia
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Henning D, Popp, Vanessa, Kohl, Nicole, Naumann, Johanna, Flach, Susanne, Brendel, Helga, Kleiner, Christel, Weiss, Wolfgang, Seifarth, Susanne, Saussele, Wolf-Karsten, Hofmann, and Alice, Fabarius
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Adult ,Aged, 80 and over ,Male ,DNA End-Joining Repair ,DNA Repair ,genetic instability ,Middle Aged ,Genomic Instability ,Article ,dna damage response ,lcsh:Chemistry ,Young Adult ,lcsh:Biology (General) ,lcsh:QD1-999 ,chronic myeloid leukemia ,Leukemia, Myelogenous, Chronic, BCR-ABL Positive ,hemic and lymphatic diseases ,Leukocytes, Mononuclear ,Humans ,DNA Breaks, Double-Stranded ,Female ,dna double-strand breaks ,lcsh:QH301-705.5 ,Aged ,DNA Damage - Abstract
DNA damage and alterations in the DNA damage response (DDR) are critical sources of genetic instability that might be involved in BCR-ABL1 kinase-mediated blastic transformation of chronic myeloid leukemia (CML). Here, increased DNA damage is detected by γH2AX foci analysis in peripheral blood mononuclear cells (PBMCs) of de novo untreated chronic phase (CP)-CML patients (n = 5; 2.5 γH2AX foci per PBMC ± 0.5) and blast phase (BP)-CML patients (n = 3; 4.4 γH2AX foci per PBMC ± 0.7) as well as CP-CML patients with loss of major molecular response (MMR) (n = 5; 1.8 γH2AX foci per PBMC ± 0.4) when compared to DNA damage in PBMC of healthy donors (n = 8; 1.0 γH2AX foci per PBMC ± 0.1) and CP-CML patients in deep molecular response or MMR (n = 26; 1.0 γH2AX foci per PBMC ± 0.1). Progressive activation of erroneous non-homologous end joining (NHEJ) repair mechanisms during blastic transformation in CML is indicated by abundant co-localization of γH2AX/53BP1 foci, while a decline of the DDR is suggested by defective expression of (p-)ATM and (p-)CHK2. In summary, our data provide evidence for the accumulation of DNA damage in the course of CML and suggest ongoing DNA damage, erroneous NHEJ repair mechanisms, and alterations in the DDR as critical mediators of blastic transformation in CML.
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- 2020
15. The Measurement of Time
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Bruce D. Popp
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Anticipation (artificial intelligence) ,media_common.quotation_subject ,Sensation ,Consciousness ,Psychology ,Cognitive psychology ,media_common ,Domain (software engineering) - Abstract
As long as we don’t leave the domain of consciousness, the concept of time is relatively clear. Not only do we easily distinguish the present sensation from the memory of past sensations or the anticipation of future sensations, but we know perfectly well what we mean to say when we affirm that, of two conscious phenomena of which we have kept a memory, one came before the other or else that, of two expected conscious phenomena, one will come before the other.
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- 2020
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16. Henri Poincaré: Electrons to Special Relativity
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Bruce D. Popp
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- 2020
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17. Electromagnetic Phenomena in a System Moving with Any Velocity Smaller than That of Light
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Bruce D. Popp
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Physics ,symbols.namesake ,Presentation ,Classical mechanics ,Electromagnetic Phenomena ,media_common.quotation_subject ,Lorentz transformation ,Poincaré conjecture ,symbols ,media_common - Abstract
A clean, reformatted presentation of H. A. Lorentz 1904 paper, provided for the convenience of readers of the translations in this book of H. Poincare’s papers wishing to read them together.
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- 2020
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18. Contributions of Abraham, Lorentz and Poincaré to Classical Theory of Electrons
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Bruce D. Popp
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Physics ,symbols.namesake ,Quantum electrodynamics ,Lorentz transformation ,Poincaré conjecture ,Cathode ray ,symbols ,Electron ,Radiation ,Physics::Classical Physics ,Electromagnetic mass ,Fundamental interaction ,Radioactive decay - Abstract
Max Abraham, Hendrik Lorentz and Henri Poincare developed theories of electrons in the years following the discovery of electrons in cathode rays and in a component of the radiation from radioactive elements. The subjects covered in their theories include electrodynamics of moving particles, the origins of mass and implications for other fundamental forces. Highlights include electromagnetic mass, the stability of electrons, and experimental evidence for the dependence of relativistic mass on velocity.
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- 2020
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19. Poincaré as a Physicist
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Bruce D. Popp
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symbols.namesake ,Work (electrical) ,media_common.quotation_subject ,Poincaré conjecture ,symbols ,Physicist ,Reputation ,media_common ,Epistemology - Abstract
Henri Poincare’s reputation as a mathematician is exceptional. What can we tell about his work in physics from the articles translated in Part I of this book? Here I identify some things that distinguish his work, for better or worse. His efforts to explain and clarify the work of others, find and use postulates or basic principles, and his innovation with analytical methodology is reviewed. A brief census of his predictions and missed opportunities for predictions is followed by a consideration of why he didn’t make the predictions that it appears he could have.
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- 2020
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20. On the Dynamics of the Electron
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Bruce D. Popp
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Snell's law ,Physics ,Absolute time and space ,Aberration of light ,Square (algebra) ,Motion (physics) ,law.invention ,Telescope ,Stars ,symbols.namesake ,Classical mechanics ,law ,Reflection (physics) ,symbols - Abstract
The article translated in this chapter is commonly known as the Palermo paper. On first consideration it seemed that the aberration of light and the optical and electrical phenomena associated with it were going to provide us a means for determining the absolute motion of the Earth or more accurately its motion, not with respect to the other stars, but with respect to the ether. Fresnel had already tried it, but he soon recognized that the motion of the Earth did not change the laws of refraction and reflection. Analogous experiments, like that of the water-filled telescope and all those where only first-order terms in the aberration were considered were to give only negative results; the explanation for this was soon found. But, Michelson, who had imagined an experiment sensitive to the terms depending on the square of the aberration, failed in turn.
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- 2020
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21. Lorentz’s Theory and the Conservation of Momentum
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Bruce D. Popp
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Physics ,symbols.namesake ,Theoretical physics ,Lorentz transformation ,Moment (physics) ,symbols ,State (functional analysis) ,Glory - Abstract
Most likely it will seem strange that at a moment raised to the glory of Lorentz I return to the considerations that I previously presented as an objection to his theory. I could state that the following pages instead are of a nature to reduce this objection and not deepen it.
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- 2020
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22. Discovery of the Electron: Cathode Rays
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Bruce D. Popp
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Physics ,Work (thermodynamics) ,Hydrogen ,chemistry ,Cathode ray ,chemistry.chemical_element ,Experimental work ,Subatomic particle ,Electron ,Atomic physics ,Electric charge ,Charged particle - Abstract
Poincare’s work on dynamics of the electron provides a classical theory of subatomic charged particles to accompany the experimental work done over the decade following Jean Perrin’s work in 1895. This chapter is the first of two parts that look at the discovery of the electron, the experimental work that established that electrical charge is discrete and that electrons have a mass that is small compared to hydrogen.
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- 2020
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23. Three Letters to H. A. Lorentz
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Bruce D. Popp
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Physics::General Physics ,symbols.namesake ,Theoretical physics ,Philosophy ,Lorentz transformation ,Poincaré conjecture ,symbols ,Physics::Classical Physics - Abstract
Between late April and early June 1905, H. Poincare wrote three letters to H. Lorentz with key observations on Lorentz’s paper from 1904. These letters provide an insight into what Poincare saw as key differences between his work in progress and the work published by Lorentz.
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- 2020
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24. Electricity – On the Dynamics of the Electron
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Bruce D. Popp
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Classical mechanics ,Dynamics (music) ,business.industry ,Session (computer science) ,Electron ,Electricity ,business ,Mathematics - Abstract
Note presented by Henri Poincare to the June 5, 1905 weekly session of the Academie des Sciences.
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- 2020
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25. Einstein, Poincaré and the Origins of Special Relativity
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Bruce D. Popp
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symbols.namesake ,Theoretical physics ,Lorentz transformation ,Philosophy ,Poincaré conjecture ,symbols ,Einstein ,Special relativity (alternative formulations) - Abstract
Going back over 60 years now, there has been extensive discussion of whether Poincare (and Lorentz) deserve credit for discovering special relativity. Two papers by Poincare translated in this book are cited to advance the case for giving Poincare precedence. This chapter considers the objectives set out by Poincare and Einstein at the beginning of their papers, looks at the beginning of the discussion, and concludes with a look at some recent work about the discussion.
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- 2020
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26. Adoption of Vector Notation for Classical Electrodynamics
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Bruce D. Popp
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Curl (mathematics) ,Algebra ,symbols.namesake ,law ,Poincaré conjecture ,symbols ,Classical electromagnetism ,Cartesian coordinate system ,Vector notation ,Physics::Classical Physics ,Differential operator ,Mathematics ,law.invention - Abstract
Poincare wrote out Cartesian components as separate variables and did not use vector notation or vector differential operators such as dell and curl. This leads to less notational conciseness and may cause generations of physicists who learned from works like Jackson (Classical Electrodynamics, 1999) (or other editions) to pause and think a few minutes before recognizing what would otherwise be a familiar equation.
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- 2020
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27. Antibody Response to Vaccination with BNT162b2, mRNA-1273, and ChADOx1 in Patients with Myeloid and Lymphoid Neoplasms
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Susanne Saussele, Henning D. Popp, Michael Neumaier, Jil Rotterdam, Mohamad Jawhar, Laurenz Steiner, Catharina Gerhards, Margot Thiaucourt, Andreas Reiter, Juliana Schwaab, Karin Bonatz, Wolf-Karsten Hofmann, and Sebastian Kreil
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Messenger RNA ,Myeloid ,business.industry ,Immunology ,Cell Biology ,Hematology ,613.Acute Myeloid Leukemias: Clinical and Epidemiological ,Biochemistry ,Vaccination ,Antibody response ,medicine.anatomical_structure ,Medicine ,Lymphoid neoplasms ,In patient ,business - Abstract
Background: In general, patients with hematological diseases are predisposed to develop infections. Severe COVID-19 infection associated with high mortality is more likely in these patient cohorts compared to the general population. Due to immune defects related to the primary disease and/or to immunosuppressive treatment regimes, vaccination efficacy may be reduced in patients with hematological diseases. So far, data on this area are limited. Aim: To evaluate vaccination-related antibody response to BNT162b2, mRNA-1273, and ChADOx1 in patients with hematological disorders. Patients and methods: In this interim analysis of a prospective, observational single-center study, we report antibody levels at least 2 weeks after COVID-19 vaccination. A FDA/CE approved electrochemiluminescent assay (ECLIA) (Elecsys®, Roche, Mannheim, Germany) was used to quantify antibodies, pan Ig (including IgG) against the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. The assay has a measurement range of 0.4 to 250 U/mL, with a concentration ≥0.8 U/ml considered as positive. Data were analyzed for patients without detection of anti-N (nucleocapsid) SARS-CoV-2 antibody (i.e., without having passed SARS-CoV-2 infection). All tests were performed according to the manufacturer's instructions in an accredited laboratory at the University Hospital Mannheim. Results: Between February 2021 and July 2021, a total of 175 patients with hematological diseases were included in this study. The median age was 66 years (range 21-90 years), and 81 (46.3%) were female. The antibody levels were measured at least 14 days (median, 58 days) after the 2 nd vaccination. The patients were vaccinated with BNT162b2 (BioNTech, n=134), mRNA-1273 (Moderna, n=19), ChADOx1 (AstraZeneca, n=12), or got the first vaccination with BNT162b2 and the second with ChADOx1 (n=10). Overall, 145/175 (82.9%) were diagnosed with a malignant hematological disease (myeloid neoplasms, n=108; lymphoid neoplasms, n=37) and 30/175 with a non-malignant hematological disease (autoimmune disease, n=24; benign, n=6). 124 patients (70.1%) were on active therapy, and 51 patients (29.1%) were previously treated or treatment naïve. Correlation to specific therapies is ongoing and will be presented. In general, vaccination-related antibody response was positive (≥0.8 U/mL) in 148/175 (84.6%) patients with a median level of 208.6 U/mL (range 0.8-250.00) and negative ( In myeloid neoplasms, patients with classical myeloproliferative neoplasm (MPN) had the highest negative result for antibodies with 4/7 (57.1%) followed by myelodysplastic syndrome (MDS) 2/7 (28.6%). Interestingly, all patients with chronic myeloid leukemia (CML) had a measurable immune response. In lymphoid neoplasms, patients with low-grade non-hodgkin lymphoma (NHL) (predominately chronic lymphocytic leukemia, CLL) had the highest negative antibody result 13/16 (81.3%) followed by high-grade NHL 4/8 (50%; predominately diffuse large b-cell lymphoma, DLBCL). In non-malignant hematological diseases, only patients with autoimmune diseases had a negative result. Conclusion: A remarkable group of patients with hematological disease were measured with no or low immune response after 2 nd COVID-vaccination, especially those with low-grade NHL, MDS and autoimmune disease. It seems that the percentage of patients with MPN and low response is less critical. No problems appeared in CML patients. Further explorations are needed with focus on potential risk of COVID infections despite full vaccination: The potential of 3 rd booster vaccination should be explored within clinical trials. Disclosures Reiter: AOP Orphan Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Celgene/BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support; Incyte: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Blueprint Medicines: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Abbvie: Membership on an entity's Board of Directors or advisory committees; Deciphera: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses. Kreil: Novartis: Research Funding. Hofmann: Amgen: Honoraria; BMS: Honoraria; Novartis: Honoraria. Jawhar: Takeda: Honoraria, Other: Travel support; Blueprint Medicines: Honoraria; Stemline: Consultancy, Honoraria; Celgene: Other: Travel support; Novartis: Consultancy, Honoraria, Other: Travel support, Speakers Bureau. Saussele: Roche: Honoraria; Pfizer: Honoraria; Incyte: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding.
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- 2021
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28. PO-1705 Evaluation of a markerless SGRT-only workflow for breast cancer patients
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Oliver J. Ott, Christoph Bert, T. Sauer, and D. Popp
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Oncology ,medicine.medical_specialty ,Workflow ,Breast cancer ,business.industry ,Internal medicine ,medicine ,Radiology, Nuclear Medicine and imaging ,Hematology ,medicine.disease ,business - Published
- 2021
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29. Investigations of Near Miss Incidents—New Facility Construction and Commissioning Activities
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Josh D. Popp and Mark S. Scarborough
- Subjects
Control and Systems Engineering ,Electrical and Electronic Engineering ,Industrial and Manufacturing Engineering - Published
- 2017
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30. PO-1904: ROI optimisation for surface guided radiation therapy
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D. Popp, Rainer Fietkau, Christoph Bert, and T. Sauer
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Materials science ,Oncology ,Surface Guided Radiation Therapy ,Radiology, Nuclear Medicine and imaging ,Hematology ,Biomedical engineering - Published
- 2020
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31. [Correction: Wnt signaling in cutaneous wound healing]
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K S, Houschyar, C, Tapking, B, Puladi, D, Popp, D, Duscher, S, Rein, G, Reumuth, G, Grieb, L K, Branski, F, Siemers, M, Lehnhardt, and A S, Yazdi
- Published
- 2019
32. [Wnt signaling in cutaneous wound healing]
- Author
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K S, Houschyar, C, Tapking, B, Puladi, D, Popp, D, Duscher, S, Rein, G, Reumuth, G, Grieb, L K, Branski, F, Siemers, M, Lehnhardt, and A S, Yazdi
- Subjects
Wound Healing ,Animals ,Humans ,Cell Differentiation ,Skin Diseases ,Wnt Signaling Pathway ,Skin - Abstract
Human skin is an efficient barrier that protects the organism from noxious substances. Wounds destroy this barrier. Wound healing is a phased physiological regeneration of the destroyed tissue that ideally leads to occlusion of a wound, in particular by regeneration of connective tissue and capillaries. The Wnt signaling pathway is a highly conserved signal transduction cascade across the animal kingdom that controls basic cellular interactions in multicellular organisms. Accordingly, through the Wnt signaling path many processes, e. g. as the balance between proliferation and differentiation or apoptosis, coordinated. Wnt signaling is activated by a wound and participates in each subsequent phase of the healing process, beginning with inflammatory control and programmed cell death, to the mobilization of stem cells within the wound. Endogenous Wnt signaling is an attractive therapeutic approach to assist in the repair of skin wounds, as the complex mechanisms of the Wnt signaling pathway have become increasingly understood over the years. This review summarizes current data to clarify the role of Wnt signaling in the wound healing process of the skin.Die menschliche Haut ist eine effiziente Barriere, die den Organismus vor Noxen schützt. Wunden zerstören diese Barriere. Die Wundheilung ist eine in Phasen ablaufende physiologische Regeneration des zerstörten Gewebes, die im Idealfall zum Verschluss einer Wunde, insbesondere durch Neubildung von Bindegewebe und Kapillaren, führt. Der Wnt-Signalweg ist eine im gesamten Tierreich stark konservierte Signaltransduktionskaskade, durch die grundlegende zelluläre Interaktionen in multizellulären Organismen gesteuert werden. Entsprechend werden durch den Wnt-Signalweg viele Prozesse, z. B. die Balance zwischen Proliferation und Differenzierung oder die Apoptose, koordiniert. Die Wnt-Signalisierung wird durch eine Wunde aktiviert und nimmt an jeder nachfolgenden Phase des Heilungsprozesses teil, beginnend mit der Entzündungskontrolle und des programmierten Zelltods bis zur Mobilisation von Stammzellen innerhalb der Wunde. Die endogene Wnt-Signalverstärkung stellt einen attraktiven therapeutischen Ansatz dar, um die Wiederherstellung von Hautwunden zu unterstützen, da die komplexen Mechanismen des Wnt-Signalwegs im Laufe der Jahre zunehmend verstanden wurden. In dieser Übersichtsarbeit werden die aktuellen Daten zusammengefasst, um die Rolle der Wnt-Signalgebung beim Wundheilungsprozess der Haut zu verdeutlichen.
- Published
- 2019
33. Comparison of RNA-Based Versus DNA-Based Quantitative KIT D816V Mutation Analysis Reveals Significant Disparity in Patients with Advanced Systemic Mastocytosis
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Wolf-Karsten Hofmann, Mohamad Jawhar, Verena Haselmann, Peter Bugert, Henning D. Popp, Juliana Schwaab, Georgia Metzgeroth, Karl Sotlar, Andreas Reiter, Thomas Kielsgaard Kristensen, Sven Schneider, Alice Fabarius, Johannes Lübke, Nicole Naumann, and Oliver Hofmann
- Subjects
Oncology ,medicine.medical_specialty ,business.industry ,RNA-Directed DNA Polymerase ,Immunology ,RNA ,Cell Biology ,Hematology ,medicine.disease ,Biochemistry ,law.invention ,Kit d816v ,chemistry.chemical_compound ,chemistry ,law ,Internal medicine ,Mutation testing ,medicine ,Midostaurin ,Systemic mastocytosis ,business ,Polymerase chain reaction ,DNA - Abstract
Systemic mastocytosis (SM) is characterized by activating mutations in KIT, usually KIT D816V in >90% of patients. According to the WHO classification, detection of KIT D816V is a minor diagnostic criterion. Moreover, a reduction of the RNA-based KIT D816V expressed allele burden (EAB) of ≥25% at month 6 is a favorable marker for improved survival in midostaurin-treated advanced SM (AdvSM) patients. However, only limited data exist upon the comparison between RNA-based and DNA-based quantitative KIT D816V mutation analyses. We therefore collected peripheral blood samples from 161 SM patients (indolent SM [ISM], n=40; AdvSM, n=121) at time of referral. We applied a real time reverse-transcriptase polymerase chain reaction (qRT-PCR) assay for assessment of the KIT D816V EAB and a chip-based digital PCR (dPCR) for the quantification of the DNA-based KIT D816V variant allele frequency (VAF, QuantStudio 3D dPCR System, ThermoFisher Scientific, Massachusetts, USA). The limit of detection (LOD) was assessed through serial dilution experiments with DNA from healthy individuals and DNA from a SM patient with a KIT D816V VAF of approximately 50%. All samples were analyzed in two independent dPCR runs. In an inital round-robin test for an inter-laboratory (n=4) comparison on 30 DNA samples (ISM, n=7; AdvSM, n=19), we found a very good correlation between 3 different chip-based digital PCR systems (dPCR; droplet-based dPCR, ddPCR, BioRad Laboratories, California, USA; quantitative real-time PCR, qPCR, California, USA; dPCR vs. ddPCR r=0.99, R2=0.99; dPCR vs. qPCR r=0.99, R2=0.98). In ISM patients, the comparison between EAB and VAF revealed a strong linear relationship with a correlation (r) of 0.91 and a coefficient of determination (R2) of 0.84, which was significantly inferior (r=0.71; R2=0.5) in AdvSM patients. In 45/121 (37%) and 76/121 (63%) of AdvSM patients, the EAB/VAF ratio was ≤2 (cohort A) or >2 (cohort B). To confirm the significant disparity between EAB and VAF in individual patients, serial analyses of at least 3 samples in 12 patients revealed a stable EAB/VAF ratio during follow-up. The comparison between cohort A and cohort B revealed significant differences in terms of a higher median hemoglobin level (p=0.006), a lower percentage of patients with hemoglobin 2 present with an aggressive phenotype and adverse prognosis as compared to patients with EAB/VAF ratio ≤2. We therefore recommend to routinely determine KIT D816V EAB and VAF in AdvSM patients. Disclosures Fabarius: Novartis: Research Funding. Reiter:Blueprint: Consultancy, Honoraria, Other: Travel reimbursement; Deciphera: Consultancy, Honoraria, Other: Travel reimbursement; Novartis: Consultancy, Honoraria, Other: Travel reimbursement, Research Funding.
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- 2019
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34. Ultranarrow Linewidth and Stable Photonic-Atomic Laser
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Zachary L. Newman, S Kang, Scott B. Papp, Wei Zhang, David R. Carlson, Liron Stern, John Kitching, and D. Popp
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Laser linewidth ,Atom laser ,Materials science ,business.industry ,Optoelectronics ,Photonics ,business - Published
- 2019
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35. Genotoxic Bystander Signals from Irradiated Human Mesenchymal Stromal Cells Mainly Localize in the 10–100 kDa Fraction of Conditioned Medium
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Oliver Drews, Vanessa Kohl, Wolf-Karsten Hofmann, Miriam Bierbaum, Helga Kleiner, Ali Darwich, Susanne Brendel, Johanna Flach, Henning D. Popp, Christel Weiss, Alice Fabarius, Ahmed Jawhar, and Wolfgang Seifarth
- Subjects
Male ,0301 basic medicine ,Cell ,CD34 ,Antigens, CD34 ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Chromosomal Instability ,bystander signals ,medicine ,Bystander effect ,Humans ,Progenitor cell ,lcsh:QH301-705.5 ,Aged ,Cell Proliferation ,Aged, 80 and over ,Chemistry ,X-Rays ,Mesenchymal stem cell ,leukemia ,Mesenchymal Stem Cells ,Bystander Effect ,General Medicine ,Middle Aged ,medicine.disease ,CD34+ cells ,Molecular biology ,Molecular Weight ,Haematopoiesis ,Leukemia ,030104 developmental biology ,medicine.anatomical_structure ,lcsh:Biology (General) ,Culture Media, Conditioned ,030220 oncology & carcinogenesis ,Female ,radiation-induced bystander effects ,mesenchymal stromal cells ,DNA ,DNA Damage ,Mutagens - Abstract
Genotoxic bystander signals released from irradiated human mesenchymal stromal cells (MSC) may induce radiation-induced bystander effects (RIBEs) in human hematopoietic stem and progenitor cells (HSPC), potentially causing leukemic transformation. Although the source of bystander signals is evident, the identification and characterization of these signals is challenging. Here, RIBEs were analyzed in human CD34+ cells cultured in distinct molecular size fractions of medium, conditioned by 2 Gy irradiated human MSC. Specifically, γH2AX foci (as a marker of DNA double-strand breaks) and chromosomal instability were evaluated in CD34+ cells grown in approximate (I) <, 10 kDa, (II) 10–100 kDa and (III) >, 100 kDa fractions of MSC conditioned medium and un-/fractionated control medium, respectively. Hitherto, significantly increased numbers of γH2AX foci (p = 0.0286) and aberrant metaphases (p = 0.0022) were detected in CD34+ cells grown in the (II) 10–100 kDa fraction (0.67 ± 0.10 γH2AX foci per CD34+ cell ∨ 3.8 ± 0.3 aberrant metaphases per CD34+ cell sample, mean ± SEM) when compared to (I) <, 10 kDa (0.19 ± 0.01 ∨ 0.3 ± 0.2) or (III) >, 100 kDa fractions (0.23 ± 0.04 ∨ 0.4 ± 0.4) or un-/fractionated control medium (0.12 ± 0.01 ∨ 0.1 ± 0.1). Furthermore, RIBEs disappeared after heat inactivation of medium at 75 °C. Taken together, our data suggest that RIBEs are mainly mediated by the heat-sensitive (II) 10–100 kDa fraction of MSC conditioned medium. We postulate proteins as RIBE mediators and in-depth proteome analyses to identify key bystander signals, which define targets for the development of next-generation anti-leukemic drugs.
- Published
- 2021
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36. Henri Poincaré: Electrons to Special Relativity : Translation of Selected Papers and Discussion
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Bruce D Popp and Bruce D Popp
- Subjects
- Electrodynamics, Physics—Philosophy, Mathematical physics
- Abstract
Produced by an award-winning translator of Henri Poincaré, this book contains translations of several seminal articles by Poincaré and discusses the experimental and theoretical investigations of electrons that form their context. In the 1950s, a dispute ignited about the origin of the theory of special relativity and thrust considerable notoriety on a paper written by Henri Poincaré in 1905. Accordingly, Part I presents the relevant translations of Poincaré's work showing that radiation carries momentum and the covariance of the equations of electrodynamics, the continuity equation for charge, and the spacetime interval. Part II then discusses investigations by Thomson, Becquerel, and Kaufmann of electrons in diverse contexts; contributions of Abraham, Lorentz and Poincaré to a theory of electrons that includes Lorentz transformations and explains the dependence of mass on velocity; and finally, Poincaré's exploration of the relativity principle, electron stability, and gravitation while rejecting absolute motion (ether) and an electromagnetic origin of mass. Part III contains the 1904 article by H. A. Lorentz presenting his transformations.This book will be a fascinating read to graduate-level students, physicists, and science historians who are interested in the development of electrodynamics and the classical, relativistic theory of electrons at the beginning of the 20th century.
- Published
- 2020
37. Beneficial Immune Effects of Myeloid-Related Proteins in Kidney Transplant Rejection
- Author
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Marko J.K. Mallat, Niels V. Rekers, Frans H.J. Claas, C. Kerkhoff, P. P. M. C. van Miert, C. van Kooten, Michael Eikmans, M.C. van Groningen, J.W. de Fijter, Natascha N T Goemaere, Godelieve M.J.S. Swings, Johannes Roth, D. Popp, Britt-Sabina Petersen, D. Baeten, Malu Zandbergen, Sebastiaan Heidt, Jacqueline D.H. Anholts, Ingeborg M. Bajema, Marina D. Kraaij, Pathology, Amsterdam institute for Infection and Immunity, Clinical Immunology and Rheumatology, and Publica
- Subjects
Adult ,Graft Rejection ,Male ,0301 basic medicine ,Myeloid ,T-Lymphocytes ,T cell ,030230 surgery ,Kidney Function Tests ,S100A9 ,S100A8 ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,Risk Factors ,Calgranulin B ,Humans ,Immunology and Allergy ,Medicine ,Calgranulin A ,Pharmacology (medical) ,chemistry.chemical_classification ,Transplantation ,Reactive oxygen species ,business.industry ,Effector ,Myeloid-Derived Suppressor Cells ,Graft Survival ,Middle Aged ,Prognosis ,Kidney Transplantation ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Case-Control Studies ,Cancer research ,Kidney Failure, Chronic ,Female ,business ,Biomarkers ,Follow-Up Studies ,Glomerular Filtration Rate - Abstract
Acute rejection is a risk factor for inferior long-term kidney transplant survival. Although T cell immunity is considered the main effector in clinical acute rejection, the role of myeloid cells is less clear. Expression of S100 calcium-binding protein A8 (S100A8) and S100A9 was evaluated in 303 biopsies before and after transplantation from 190 patients. In two independent cohorts of patients with acute rejection (n = 98 and n = 11; mostly cellular rejections), high expression of S100 calcium-binding protein A8 (S100A8) and A9 (S100A9) was related to improved graft outcome. Mechanisms of action of the S100 molecules were investigated. In the graft and peripheral blood cells, S100A8 and S100A9 expression correlated with myeloid-derived suppressor markers. In line with this finding, recombinant S100A8 and S100A9 proteins inhibited maturation and the allogeneic T cell stimulatory capacity of dendritic cells. S100A9 enhanced the production of reactive oxygen species by macrophages, which suppressed T cell activity at low concentrations in the form of hydrogen peroxide. Intragraft S100A8 and S100A9 expression linked to reduced expression of T cell immunity and tissue injury markers and higher expression of immune regulatory molecules. This study sheds new light on the importance of myeloid cell subsets in directing the outcome of T cell-mediated acute rejection. The authors find an association between levels of S100 calcium-binding proteins A8 and A9 during acute kidney transplant rejection with graft outcome, and that these myeloid cell-expressed proteins have immunoregulatory effects toward T cells.
- Published
- 2016
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38. Accumulation of DNA damage and alteration of the DNA damage response in monoclonal B-cell lymphocytosis and chronic lymphocytic leukemia
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Johanna Flach, Alice Fabarius, Susanne Brendel, Christel Weiss, Wolf-Karsten Hofmann, Helga Kleiner, Wolfgang Seifarth, Torsten J. Schulze, Henning D. Popp, Sabrina Ruppenthal, Frederik Wenz, and Sven Schneider
- Subjects
Adult ,Male ,Cancer Research ,DNA damage ,Chronic lymphocytic leukemia ,Antigens, CD19 ,Lymphocytosis ,Biology ,Genomic Instability ,Pathogenesis ,Clonal Evolution ,Histones ,03 medical and health sciences ,Cytogenetics ,0302 clinical medicine ,medicine ,Humans ,DNA Breaks, Double-Stranded ,Genetic Predisposition to Disease ,Genetic Association Studies ,Aged ,B-Lymphocytes ,Hematology ,Middle Aged ,medicine.disease ,Flow Cytometry ,Leukemia, Lymphocytic, Chronic, B-Cell ,body regions ,Oncology ,030220 oncology & carcinogenesis ,Monoclonal ,Mutation ,Cancer research ,Monoclonal B-cell lymphocytosis ,Female ,Immunoglobulin Heavy Chains ,Biomarkers ,030215 immunology ,DNA Damage - Abstract
Accumulation of DNA damage and alteration of the DNA damage response (DDR) are critical features of genetic instability that is presumed to be implicated in the pathogenesis of monoclonal B-cell lymphocytosis (MBL) and chronic lymphocytic leukemia (CLL). Here, we show increased numbers of γH2AX foci, a marker of DNA double-strand breaks (DSB), in CD19+ cells of CLL patients as compared to CD19+ cells of MBL patients and healthy individuals. Furthermore, numerous γH2AX/53BP1 foci in CLL cells suggest activation of error-prone non-homologous end-joining repair mechanisms. Signatures of DDR proteins further indicate alterations of the DDR in CLL in contrast to a largely regular activation in MBL and healthy controls. In summary, our results provide evidence for the stepwise accumulation of DNA damage in the progression of MBL towards CLL and suggest increased DNA damage, error-prone DNA repair and altered DDR signaling to be critical mechanisms of clonal evolution in MBL and CLL.
- Published
- 2018
39. Changing the Electrical Safety Culture at a Large Industrial Plant in the Middle East Region
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Nicolas Ghosn, Josh D. Popp, and Ahmad Saheb
- Subjects
Shock (economics) ,Engineering ,Risk analysis (engineering) ,business.industry ,Process (engineering) ,Corporate governance ,Fossil fuel ,Arc flash ,Production (economics) ,Safety culture ,business ,Low voltage - Abstract
Industries other than oil and gas in the Middle-East region have grown quickly over the last decades to meet the increase in demand of emerging local and international markets at competitive prices. Upgrades and modifications to these industrial processes under different international standards leads to situations in which heterogeneous and fragmented electrical systems are installed and operated without having proper electrical safety programs in place. Electrical hazards associated with high and low voltage systems are not fully understood, calculated, and mitigated for all personnel. This paper describes the process of implementing an electrical safety program for a large industrial plant in the Middle East region and cultural challenges faced in its implementation and that of similar regional industrial manufacturers. An approach to gap assessment, targeted hazard mitigation programs, electrical safety program development, and training of personnel is provided. This approach was used with the goal of establishing good foundations, capabilities, and processes to address electrical risk and sustain continuous improvement. The implementation of an Electrical Safety Program that pro-actively manages and mitigates arc flash and shock hazards and puts in place a corporate independent governance structure that includes electrical workers from different sites and production areas is described. In an effort to tackle the cultural and behavioral challenges in an established industry in a region where electrical safety has recently emerged as a serious industrial risk, the Electrical Safety Program developed integrates intensive trainings and communications to drive change in modus operandi.
- Published
- 2018
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40. Symmetric piezoelectric CVG with digital control electronics
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Jeremy, Jose Beitia, A. Dorian Challoner, and D. Popp
- Subjects
Resonator ,Noise measurement ,law ,Computer science ,Capacitive sensing ,Rate gyro ,Electronic engineering ,Gyroscope ,Digital control ,Breadboard ,Noise (electronics) ,law.invention - Abstract
This paper presents the digital control of a symmetric, piezoelectrically-transduced Coriolis Vibratory Gyro (CVG) with improved performance and design for compact ASIC implementation in terrestrial and space environments. Previously a metallic PZT transduced cylindrical resonator with simple analog control electronics resulted in a successful low noise rate gyro produced by Innalabs [1, 2] for stabilization and targeting applications and satellite pointing. This work details key benefits of applying a very low noise digital control and demodulation approach that extends InertialWave's previous work on generalized feedback control of capacitive CVG's [3]. This has been demonstrated at breadboard level to further reduce rate noise toward the very low, 60 μdeg/rt-h mechanical thermal noise (MTN) inherent in its massive 23 mm, high quality resonator and points to a clear path for achieving navigation grade performance in a mass producible CVG and compact three-axis IRU or IMU assembly.
- Published
- 2018
- Full Text
- View/download PDF
41. Immunofluorescence Microscopy of γH2AX and 53BP1 for Analyzing the Formation and Repair of DNA Double-strand Breaks
- Author
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Henning D, Popp, Susanne, Brendel, Wolf-Karsten, Hofmann, and Alice, Fabarius
- Subjects
Cellular Biology ,DNA Repair ,Microscopy, Fluorescence ,Humans ,DNA Breaks, Double-Stranded ,Tumor Suppressor p53-Binding Protein 1 - Abstract
DNA double-strand breaks (DSB) are serious DNA lesions. Analysis of the formation and repair of DSB is relevant in a broad spectrum of research areas including genome integrity, genotoxicity, radiation biology, aging, cancer, and drug development. In response to DSB, the histone H2AX is phosphorylated at Serine 139 in a region of several megabase pairs forming discrete nuclear foci detectable by immunofluorescence microscopy. In addition, 53BP1 (p53 binding protein 1) is another important DSB-responsive protein promoting repair of DSB by nonhomologous end-joining while preventing homologous recombination. According to the specific functions of γH2AX and 53BP1, the combined analysis of γH2AX and 53BP1 by immunofluorescence microscopy may be a reasonable approach for a detailed analysis of DSB. This manuscript provides a step-by-step protocol supplemented with methodical notes for performing the technique. Specifically, the influence of the cell cycle on γH2AX foci patterns is demonstrated in normal fibroblasts of the cell line NHDF. Further, the value of the γH2AX foci as a biomarker is depicted in x-ray irradiated lymphocytes of a healthy individual. Finally, genetic instability is investigated in CD34+ cells of a patient with acute myeloid leukemia by immunofluorescence microscopy of γH2AX and 53BP1.
- Published
- 2017
42. Incidence and prognostic impact of cytogenetic aberrations in patients with systemic mastocytosis
- Author
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Nicole Naumann, Hans-Peter Horny, Peter Valent, Andreas Reiter, Juliana Schwaab, Sebastian Kluger, Manja Meggendorfer, Alice Fabarius, Claudia Haferlach, Johannes Lübke, Nicholas C.P. Cross, Nada Khaled, Georgia Metzgeroth, Karl Sotlar, Mohamad Jawhar, Gudrun Göhring, Henning D. Popp, Brigitte Schlegelberger, and Wolf-Karsten Hofmann
- Subjects
0301 basic medicine ,Adult ,Male ,Cancer Research ,Prognostic variable ,medicine.medical_specialty ,Chromosome Disorders ,Biology ,Gastroenterology ,03 medical and health sciences ,Cytogenetics ,0302 clinical medicine ,Mastocytosis, Systemic ,Internal medicine ,Complex Karyotype ,Genetics ,medicine ,Secondary Acute Myeloid Leukemia ,Humans ,Systemic mastocytosis ,Aged ,Chromosome 7 (human) ,Aged, 80 and over ,Chromosome Aberrations ,Incidence ,Hazard ratio ,Karyotype ,Middle Aged ,Mast cell leukemia ,medicine.disease ,Prognosis ,Proto-Oncogene Proteins c-kit ,030104 developmental biology ,Phenotype ,030220 oncology & carcinogenesis ,Hematologic Neoplasms ,Karyotyping ,Cytogenetic Analysis ,Mutation ,Female - Abstract
The clinical behavior of systemic mastocytosis (SM) is strongly associated with activating mutations in KIT (D816V in >80% of cases), with the severity of the phenotype influenced by additional somatic mutations, e.g. in SRSF2, ASXL1 or RUNX1. Complex molecular profiles are frequently associated with the presence of an associated hematologic neoplasm (AHN) and an unfavorable clinical outcome. However, little is known about the incidence and prognostic impact of cytogenetic aberrations. We analyzed cytogenetic and molecular characteristics of 109 patients (KIT D816V+, n=102, 94%) with indolent (ISM, n=26) and advanced SM (n=83) with (n=73, 88%) or without AHN. An aberrant karyotype was identified in SM-AHN (16/73, 22%) patients only. In patients with an aberrant karyotype additional somatic mutations were identified in 12/16 (75%) patients. Seven of 10 (70%) patients with a poor-risk karyotype, e.g. monosomy 7 or complex karyotype, and 1/6 (17%) patients with a good-risk karyotype progressed to secondary acute myeloid leukemia (n=7) or mast cell leukemia (n=1) within a median of 40 months (range 2-190, P=0.04). In advanced SM, the median overall survival (OS) of poor-risk karyotype patients was significantly shorter than in good-risk/normal karyotype patients (4 vs. 39 months; hazard ratio 11.7, 95% CI 5.0-27.3; P
- Published
- 2017
43. Immunofluorescence Microscopy of γH2AX and 53BP1 for Analyzing the Formation and Repair of DNA Double-strand Breaks
- Author
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Alice Fabarius, Wolf-Karsten Hofmann, Susanne Brendel, and Henning D. Popp
- Subjects
0301 basic medicine ,General Immunology and Microbiology ,DNA repair ,General Chemical Engineering ,General Neuroscience ,Histone H2AX ,Myeloid leukemia ,Cell cycle ,Biology ,medicine.disease_cause ,Molecular biology ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Cell culture ,medicine ,Homologous recombination ,Genotoxicity ,DNA - Abstract
DNA double-strand breaks (DSB) are serious DNA lesions. Analysis of the formation and repair of DSB is relevant in a broad spectrum of research areas including genome integrity, genotoxicity, radiation biology, aging, cancer, and drug development. In response to DSB, the histone H2AX is phosphorylated at Serine 139 in a region of several megabase pairs forming discrete nuclear foci detectable by immunofluorescence microscopy. In addition, 53BP1 (p53 binding protein 1) is another important DSB-responsive protein promoting repair of DSB by nonhomologous end-joining while preventing homologous recombination. According to the specific functions of γH2AX and 53BP1, the combined analysis of γH2AX and 53BP1 by immunofluorescence microscopy may be a reasonable approach for a detailed analysis of DSB. This manuscript provides a step-by-step protocol supplemented with methodical notes for performing the technique. Specifically, the influence of the cell cycle on γH2AX foci patterns is demonstrated in normal fibroblasts of the cell line NHDF. Further, the value of the γH2AX foci as a biomarker is depicted in x-ray irradiated lymphocytes of a healthy individual. Finally, genetic instability is investigated in CD34+ cells of a patient with acute myeloid leukemia by immunofluorescence microscopy of γH2AX and 53BP1.
- Published
- 2017
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44. OP0091 S100a8 triggers a novel immune-regulatory mechanism in developing dendritic cells
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D. Popp, Thomas Vogl, F. Rühle, Johannes Roth, and W de Jager
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Chemokine ,Innate immune system ,biology ,business.industry ,medicine.medical_treatment ,Inflammation ,Cell biology ,Immune system ,Cytokine ,Gene expression ,medicine ,biology.protein ,TLR4 ,medicine.symptom ,business ,CD8 - Abstract
Background S100A8/A9 heterodimers are well-known alarmins that, upon release from activated or necrotic phagocytes, promote inflammation by binding to Toll-like receptor 4 (TLR4). These proteins are highly expressed in synovial phagocytes during arthritis and proved to be reliable biomarkers for monitoring disease activity in RA. Interestingly, we now identify a novel immune-regulatory mechanism of S100A8 in human monocyte-derived dendritic cells (moDCs). Objectives This study aims to analyze immune-regulatory functions of S100 proteins in human DCs. Methods MoDCs are differentiated with or without exposure to S100A8 prior to maturation with LPS. After characterization of the activation status using flow cytometry, the ability of these cells to induce autologous CD4+, CD8+, and γδ T-cell proliferation is investigated. Cytokines, secreted during development are analyzed by Luminex cytokine arrays. The metabolic state of DCs is examined by using Seahorse XFp Analyzer assays. Finally, to identify molecular mechanisms leading to an immune-regulatory phenotype, the mRNA expression of moDCs is analyzed by genome-wide gene expression arrays. Results Our results demonstrate that early exposure to S100A8 interferes with in-vitro differentiation of moDCs. Compared to controls S100A8-exposed moDCs show dramatically reduced surface expression of co-stimulatory molecules upon LPS-induced maturation. In addition, early treatment of moDCs with S100A8 alters the secretion of immune-regulatory cytokines and chemokines depending on the developmental state of moDCs. S100A8-induced effects on moDC maturation are not limited to TLR4 stimulation but rather trigger a common state of unresponsiveness. Furthermore, mitochondrial respiration and glycolytic function is diminished in S100A8-treated moDCs. As a consequence, S100A8-exposed moDCs have a reduced potential to induce autologous T-cell proliferation. We can show that these differences are mainly caused by reduced surface expression of co-stimulatory molecules on S100A8-treated moDCs. Mechanistically, genome-wide gene expression analysis reveals dramatic differences in gene expression between S100A8-exposed and conventionally differentiated moDCs. We demonstrate that S100A8 pre-treatment of moDCs significantly blocks LPS-induced gene expression during moDC activation. Interestingly, in-silico analysis of transcription factor networks predicts NFκB and C/EBPδ as master regulators of S100A8-induced effects in developing moDCs. C/EBPδ on protein level, indeed, shows reduced expression in S100A8-differentiated moDCs prior and after LPS-induced maturation when compared to conventionally differentiated moDCs. Conclusions Taken together, our results demonstrate a novel regulatory mechanism of innate immunity to prevent overwhelming immune responses. Dysregulated repression of detrimental adaptive immune responses might very well contribute to the disease phenotype in auto-immune disorders with high systemic S100A8/A9 levels. Therefore, S100A8-differentiated immune-suppressive DCs potentially represent a promising therapeutic tool to treat auto-immune diseases in the future. Disclosure of Interest None declared
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- 2017
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45. Erratum: Cumulative radiation exposure from imaging procedures and associated lifetime cancer risk for patients with lymphoma
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Grete Fabritius, Gunnar Brix, Elke Nekolla, Stefan Klein, Henning D. Popp, Mathias Meyer, Gerhard Glatting, Claudia Hagelstein, Wolf K. Hofmann, Stefan O. Schoenberg, and Thomas Henzler
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Multidisciplinary - Abstract
Scientific Reports 6: Article number: 35181; published online: 17 October 2016; updated: 03 May 2017. The original version of this Article contained a typographical error in the Abstract. “The average ED in the first year after diagnosis was significantly different for men (59 ± 33 mSv) and women (744 ± 33 mSv)-(p
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- 2017
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46. Development and integration of an electrical safety program into a new production facility's pre-commissioning and startup activities
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Mark S. Scarborough, Josh D. Popp, and Michael Nagl
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Engineering ,Equipment failure ,Engineering management ,business.industry ,Project commissioning ,Electrical equipment ,Operations management ,Commission ,Schedule (project management) ,business ,Switchgear - Abstract
This paper describes the basic elements of a company's generic, region based electrical safety program and a new facility's experience in implementing the program during the initial system turnover and energization phases of the project. Background on the site's safety by design considerations, arc flash hazard assessment, and organizational makeup provides insight on how the facility managed to tailor the ‘generic’ program to their site needs and train the organization. Specific examples highlight the need to thoroughly commission electrical equipment and systems after construction turnover and in the face of leadership pressure regarding cost and schedule. Specific examples include the challenges of energizing equipment during ongoing construction, equipment failure, and managing contract workers performing equipment commissioning.
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- 2017
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47. Knee injuries in rock climbing and bouldering
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Thilo Hotfiel, Christoph Lutter, D. Popp, and Volker Schöffl
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medicine.medical_specialty ,Physical medicine and rehabilitation ,business.industry ,Climbing ,medicine ,Orthopedics and Sports Medicine ,Physical Therapy, Sports Therapy and Rehabilitation ,Knee injuries ,business - Published
- 2018
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48. Anti-Leukemic Efficacy of Talazoparib and APE1 Inhibitor III Combined with Decitabine in Myeloid Malignancies
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Wolf-Karsten Hofmann, Helga Kleiner, Henning D. Popp, Vanessa Kohl, Johanna Flach, Christel Weiss, Susanne Brendel, Daniel Nowak, Alice Fabarius, and Wolfgang Seifarth
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Myeloid ,business.industry ,Myelodysplastic syndromes ,Immunology ,CD34 ,Decitabine ,Chronic myelomonocytic leukemia ,Myeloid leukemia ,Cell Biology ,Hematology ,medicine.disease ,Biochemistry ,medicine.anatomical_structure ,hemic and lymphatic diseases ,Monoclonal ,medicine ,Cancer research ,Cytotoxic T cell ,business ,medicine.drug - Abstract
Malignant hematopoietic cells of myelodysplastic syndromes (MDS)/chronic myelomonocytic leukemias (CMML) and acute myeloid leukemias (AML) may be particularly vulnerable to inhibition of poly(ADP ribose) polymerase 1/2 (PARP1/2) and apurinic/apyrimidinic endonuclease 1 (APE1). PARP1/2 and APE1 are critical enzymes involved in single-strand break repair and base excision repair, respectively. Here, we investigated the cytotoxic efficacy of talazoparib and APE1 inhibitor III, inhibitors of PARP1/2 and APE1, as single-agents, combined with decitabine and combined with each other in CD34+ MDS/CMML cells and in CD34+ or CD34- AML cells in comparison to healthy CD34+ donor cells. The surviving fraction of CD34+ MDS/CMML cells (n = 8; 4 MDS and 4 CMML), CD34+ or CD34- AML cells (n = 18) and healthy CD34+ donor cells (n = 8) was analyzed using the CellTiter-Glo luminescent cell viability assay (Promega, Southampton, UK). Cell proliferation of untreated MDS/CMML and AML cells was determined by trypan blue exclusion assay (Merck, Darmstadt, Germany). PARP1/APE1 mRNA expression was evaluated using validated primer sets for PARP1 (Hs_PARP1_1_SG QuantiTect Primer Assay, NM_001618) and APE1 (Hs_APEX1_1_SG QuantiTect Primer Assay, ENST00000216714) (Qiagen, Hilden, Germany). Immunofluorescence microscopy of γH2AX foci was performed using a JBW301-derived mouse monoclonal anti-γH2AX antibody (Merck). Talazoparib and APE1 inhibitor III demonstrated critical anti-leukemic efficacy as single-agents in about 19-25% of MDS/CMML/AML cell samples (Figure 1A and B). Low doses of talazoparib and APE1 inhibitor III further increased the cytotoxic efficacy of decitabine in about 78-86% of MDS/CMML/AML cell samples. Moreover, low doses of APE1 inhibitor III increased the cytotoxic efficacy of talazoparib in about 68% of MDS/CMML/AML cell samples. In summary, talazoparib and APE1 inhibitor III demonstrated substantial anti-leukemic efficacy as single-agents, in combination with decitabine and combined with each other. Hence, our findings support further investigation of these agents in sophisticated clinical trials. Figure 1 Cytotoxic efficacy of talazoparib and APE1 inhibitor III in healthy CD34+ donor cells, in CD34+ myelodysplastic syndrome (MDS)/chronic myelomonocytic leukemia (CMML) cells and in CD34+ or CD34- acute myeloid leukemia (AML) cells after 3 days of treatment. (A) The mean IC50 of talazoparib was significantly lower (*p = 0.016) in 1 MDS (MDS#2), 1 CMML (CMML#2) and 3 AML cell samples (AML#1, AML#2, AML#3) as compared to 8 healthy donor cell samples. (B) The mean IC50 of APE1 inhibitor III was substantially lower (p = 0.059) in 1 MDS (MDS#2) and 5 AML cell samples (AML#1, AML#2, AML#3, AML#6, AML#12) as compared to 8 healthy donor cell samples. Figure 1 Disclosures Fabarius: Novartis: Research Funding.
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- 2019
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49. Accumulation of DNA Damage and Alteration of the DNA Damage Response in Chronic Myeloid Leukemia
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Wolf-Karsten Hofmann, Helga Kleiner, Wolfgang Seifarth, Susanne Brendel, Vanessa Kohl, Johanna Flach, Susanne Saussele, Henning D. Popp, Alice Fabarius, and Christel Weiss
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medicine.diagnostic_test ,business.industry ,medicine.drug_class ,DNA damage ,Immunology ,Cell ,breakpoint cluster region ,Myeloid leukemia ,Cell Biology ,Hematology ,Immunofluorescence ,Biochemistry ,Peripheral blood mononuclear cell ,Tyrosine-kinase inhibitor ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,hemic and lymphatic diseases ,Cancer research ,Medicine ,DAPI ,business - Abstract
The accumulation of DNA damage and the alteration of the DNA damage response (DDR) are critical features of genetic instability that is presumed to be implicated in BCR/ABL1-mediated blastic transformation of chronic myeloid leukemia (CML). The aim of our study was to analyze underlying mechanisms of genetic instability with regard to DNA damage such as DNA double-strand breaks (DSB), DSB repair and DDR signaling during blastic transformation of CML. Immunofluorescence microscopy of γH2AX was performed for quantification of DSB in peripheral blood mononuclear cells (PBMC) of 8 healthy individuals, 24 chronic phase (CP)-CML patients under current/discontinued tyrosine kinase inhibitor (TKI) treatment (21 patients in deep molecular response (DMR), 3 patients in major molecular response (MMR)), 5 CP-CML patients under current/discontinued TKI treatment with loss of MMR, 3 de novo non-treated CP-CML patients and 2 blast phase (BP)-CML patients. In addition, immunofluorescence microscopy of γH2AX/53BP1 was used for semi-quantification of error-prone DSB repair. Furthermore, immunoblotting of p-ATM, p-ATR, p-CHK1, p-CHK2 and p-TP53 was performed in PBMC of CML patients in comparison to PBMC of healthy individuals. Our analysis revealed an increase in numbers of γH2AX foci in PBMC of CP-CML patients under current/discontinued TKI treatment with loss of MMR (1.8 γH2AX foci per PBMC ± 0.4), in PBMC of de novo non-treated CP-CML patients (2.3 γH2AX foci per PBMC ± 0.7) and in PBMC of BP-CML patients (4.9 γH2AX foci per PBMC ± 0.9) as compared to the number of γH2AX foci in PBMC of healthy individuals (1.0 γH2AX foci per PBMC ± 0.1) and in PBMC of CP-CML patients under current/discontinued TKI treatment in DMR/MMR (1.0 γH2AX foci per PBMC ± 0.1) (Figure 1A and B). Analysis of co-localizing γH2AX/53BP1 foci in PBMC suggested progressive activation of error-prone nonhomologous end-joining repair mechanisms during blastic transformation in CML. Signatures of p-ATM, p-ATR, p-CHK1, p-CHK2 and p-TP53 indicated alterations of the DDR. In summary, our data provide evidence for an accumulation of DNA damage in PBMC of CML patients towards BP-CML patients. We hypothesize that ongoing DSB generation, error-prone DSB repair and DDR alterations might be critical mechanisms of blastic transformation in CML. Figure 1 Analysis of γH2AX foci in freshly isolated peripheral blood mononuclear cells (PBMC) of healthy individuals and chronic myeloid leukemia (CML) patients. (A) Exemplary immunofluorescence microscopic images of γH2AX foci (green, Alexa 488) and cell nuclei (blue, DAPI) in PBMC of a healthy individual (HEALTHY#3), a chronic phase CML patient with a deep molecular response to tyrosine kinase inhibitor (CP-CML DMR#16), a de novo non-treated chronic phase CML patient (CP-CML#1) and a blast phase CML patient (BP-CML#2). (B) γH2AX foci levels in PBMC of healthy individuals and in PBMC of CML patients. Figure 1 Disclosures Saussele: Pfizer: Honoraria; Novartis: Honoraria, Research Funding; Incyte: Honoraria, Research Funding; BMS: Honoraria, Research Funding. Fabarius:Novartis: Research Funding.
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- 2019
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50. Increase of DNA damage and alteration of the DNA damage response in myelodysplastic syndromes and acute myeloid leukemias
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Christel Weiss, Wolf-Karsten Hofmann, Susanne Brendel, Alice Fabarius, Thomas Henzler, Henning D. Popp, and Nicole Naumann
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0301 basic medicine ,Cancer Research ,Pathology ,medicine.medical_specialty ,Focus (geometry) ,DNA Repair ,DNA damage ,Cell ,CD34 ,Biology ,Pathogenesis ,Histones ,03 medical and health sciences ,0302 clinical medicine ,Bone Marrow ,hemic and lymphatic diseases ,Cell Line, Tumor ,medicine ,Humans ,DNA Breaks, Double-Stranded ,Myelodysplastic syndromes ,Hematology ,medicine.disease ,Leukemia, Myeloid, Acute ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,Cell culture ,030220 oncology & carcinogenesis ,Myelodysplastic Syndromes ,Cancer research ,Bone marrow ,Tumor Suppressor p53-Binding Protein 1 ,DNA Damage - Abstract
Increased DNA damage and alteration of the DNA damage response (DDR) are critical features of genetic instability presumably implicated in pathogenesis of myelodysplastic syndromes (MDS) and acute myeloid leukemias (AML). We used immunofluorescence staining of γH2AX and 53BP1 for analyzing DNA double-strand breaks (DSB) in MDS and AML cell lines, in CD34+ selected cells of normal and MDS bone marrow (including three cases of chronic myelomonocytic leukemias) and in blasts of AML bone marrow. In addition, we screened for activation of the DDR by immunoblotting of p-ATM, p-ATR, p-CHK1, p-CHK2 and p-TP53. As compared to γH2AX foci levels in normal bone marrow samples (0.2 focus per CD34+ cell±0.0; mean±standard error of mean), increased levels of γH2AX foci were detected in 16/16 MDS bone marrow samples (2.8 foci per CD34+ cell±0.5), 18/18 AML bone marrow samples (5.5 foci per blast±0.5), 1/1 MDS cell line (6.4 foci per cell) and 6/6 AML cell lines (12.0 foci per cell±0.6). γH2AX and 53BP1 co-localized in all tested samples forming diffuse, clustered and marginal patterns. Further, DDR proteins were expressed heterogeneously suggesting impairment of the DDR. In summary, our results provide evidence for a continuous increase of DSB across the spectrum from MDS to AML in conjunction with an impaired DDR. Co-localization of γH2AX and 53BP1 indicates promotion of (in)effective nonhomologous end-joining repair mechanisms at sites of DSB. Moreover, γH2AX/53BP1 foci distribution presumably reveals a non-random spatial organization of the genome in MDS and AML.
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- 2016
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