12 research outputs found
Haematologia
No full text1991 / 1. szám
Storek, J. - Nepomucka, J. - Kobylka, P. - Sejkorova, J.: Intermittent-flow versus continuousflow mononuclear cell apheresis
Shimamoto, Y. - Matsuzaki, M. - Ono, K. - Sano, M. - Yamaguchi, M.: Combination therapy of M2-protocol and Interferon-# as remission induction in refractory multiple myeloma
Phan, D. T. - Ha, N. T. V. - Thuc, L. T. - Diet, N. H. - Phu, L. V. - Ninh, L. Y. - An, V. T.: Some changes in immunity and blood in relation to clinical states of dengue hemorrhagic fever patients in Vietnam
Storek, J. - Nepomucka, J. - Kobylka, P. - Sejkorova, J.: Blood count changes due to mononuclear cell apheresis
Matolcsy, A. - Izer, I. - Magyarlaki, T. - Baranyay, F.: Enzyme negative blastic transformation of chronic myeloproliferative disorders: Immunophenotyping of the blastic cell population
Soligo, D. - Luksch, R. - Quirici, N. - Foa, P. - Moneta, D. - Somalvoco, F. - Lambertenghi Deliliers, G.: Immunohistochemical evaluation of bone marrow biopsies in myelodysplastic syndrome
Czink, E. - Horváth, Cs. - Malek, A. A. - Siklósi, Gy.: Is dehydroepiandrosterone-sulphate a possible pathogenetic factor in osteopenia of patients with iron overload?
Abstracts
Correction
1991 / 2. szám
Eliopoulos, G. - Coulocheri, S. - Eliopoulos, A. - Vaiopoulos, G. - Tsantali, C. - Anagnou, N.: Impaired production of GM CSA in bone marrow and peripheral blood monocytes in two patients with severe congenital neutropenia
Cabart, P. - Kalousek, I. - Jandova, D.: Expression of chromosomal protein HMG-1 in transformed and normal human cells
El-Khatib, Y. - Gidáli, J. - Fehér, I. - Mód, A. - Poros, A. - Hollán, S.: Growth kinetics and blast-colony forming cell binding capacity of stromal cells in various haematological malignancies
Pálóczy, K. - Pócsik, É. - Kotlán, B. - Ujhelyi, E. - Timár, L. - Petrányi, G. Gy.: The pattern of activation antigen expression on T-lymphocyte subpopulation in infectious mononucleosis
Demeter, J. - Mihalik, R. - Benczúr, M. - Lehoczky, D. - Pálóczi, K.: Characterization of T lymphocyte subsets in hairy cell leukaemia: Influence of splenectomy and correlations with the clinical stage of the disease
Anagnou, N. P. - Papnicolaou, N. - Fessas, PH.: Recurrent attacks of hemolytic uremic syndrome
Thavaraj, V. - Singh, Y. - Choudhary, V. P. - Saraya, A. K.: Congenital Factor XIII deficiency. A family report
Colovic, M. - Basara, N. - Vuckovic, S. - Jankovic, G. - Suvajdzic, N. - Stosic, T. - Rolovic, Z.: Dysmegakaryocytopoiesis and thrombocytosis in a patient with acute myelomonocytic leukemia and long evolution
Sartori, M. T. - Mares, M. - Girolami, A.: Portal vein thrombosis in a patient with severe haemophilia A and post-hepatitis liver cirrhosis
Obituary
Abstracts
1991 / 3. szám
Kalmanti, M. - Kalmantis, Th. - Liacopoulou, Th. - Tsoumakas, K. - Ladis, V. - Kattamis, C.: Serum erythropoietin in regularly transfused thalassemic patients
Famodu, A. A. - Ehigiegba, A. E. - Fakoya, T. A. - Adeyi, J. - Diejomach, F. M. E.: Effects of oral contraceptive on Fibrinogen Levels in African Women
Demeter, J. - Mihalik, R. - Benczúr, M. - Lehoczky, D. - Pálóczi, K.: Peripheral blood leukocyte subpopulations a long time after posttraumatic splenectomy
Sasaki, R. - Yuasa, Y. - Bollum, F. J. - Minowada, J. - Miura, Y. - Takaku, F.: Quantitative assay of terminel deoxynucleotidyl transferase (TdT) activity using monoclonal antibodies
Choubisa, S. L.: Abnormal haemoglobins, thalassaemia and G-6-PD enzyme deficiency in Rajasthan (Western-India)
Hollán, S.: Molecular genetics - New horizons in haematology
Abstracts
Announcement
1991 / 4. szám
Sandler, S. G. - Fang, C.: Preventing transfusion-transmitted infections. Issues related to migrating populations and increasing world travel
Fibach, E. - Rachmilewitz, E. A.: A two-step liquid culture - A novel culture procedure for studying erythroid cell development
Bernard, J.: Ethics and haematology
Ghosh, K. - Abdul Rahman H. I. - Torres, E. C. - Abdul Wahab, A. - Hassanein, A. A.: Report of the first case of pyrimidine 5'-nucleotidase deficiency from Kuwait detected by a screening tsts. A case report
Rudzka, E. - Holowiecki, J. - Kachel, L. - Lawniczek, T. - Pajak, J.: Skin manifestation of extramedullary relapse in adult with acute lymphoblastic leukaemia
Caenazzo, A. - Pietrogrande, F. - Polato, G. - Piva, E. - Sartori, D. - Girolami, A.: Decreased platelet mitogenic activity in patients with diabetes mellitus
Obituary
Abstracts
Index to Volume 24
Author Index
Subject Inde
Structure-Based Design of Promysalin Analogues to Overcome Mechanisms of Bacterial Resistance
No full textThe search for antibiotics that function through novel
mechanisms
of action is ongoing, and recent progress in our lab identified the
tricarboxylic acid cycle as a viable option. Promysalin is a secondary
metabolite capable of species-specific inhibition of Pseudomonas aeruginosa, a common opportunistic pathogen.
Promysalin disrupts primary metabolism in this bacterium by competitively
inhibiting succinate dehydrogenase at the ubiquinone binding site.
However, the activity of promysalin in cellulo is marred potentially
by its chemical instability and/or propensity for efflux. To assess
the success of these novel analogues, a novel strain of P. aeruginosa harboring gene deletions of eight efflux
pumps and porins was developed and implemented. Herein, we disclose
the synthesis and biological investigation of six promysalin analogues
to overcome these liabilities and demonstrate that efflux likely plays
a significant role in tolerating the effect of the inhibitor
Observables of the Electrical Potential of the KATRIN Tritium Source from Calibration with a High-Intensity Krypton-83m Source
No full textAuthors: Moritz Machatschek, Matthias Böttcher, Caroline Fengler, Jaroslav Storek, Magnus Schlösser
Co-author: KATRIN Collaboration
The KArlsruhe TRItium Neutrino experiment currently provides the best neutrino mass upper limit of 0.8 eV/c2 (90% C. L.) in the field of direct neutrino-mass measurements [1]. This result has been obtained with only 5% of the anticipated total measurement time. However, reaching the target sensitivity of 0.2 eV/c2 at 90% C. L. not only requires the full measurement time, but also the detailed study of systematic measurement uncertainties.
One major systematic effect is linked to the electrical potential which is formed inside of the tritium source. The β-electrons generated in the source partly ionize the molecular gas and form a plasma inside a source magnetic field of 2.5 T [2]. A spatial inhomogeneity in this plasma and thus in the starting potential of the β-electrons would lead to a distortion of the β-spectrum. This effect needs to be characterized in order to reduce systematic bias in the neutrino mass measurement.
To this end we measure the line-profile of mono-energetic conversion electrons from of 83mKr, which serves as an atomic reference standard. By co-circulating trace amounts of 83mKr with tritium inside of the WGTS, spatial distortions can be precisely quantified. Most suitable for the determination of these effects are the electron conversion N-lines, which offer a vanishing intrinsic line width. Any additional broadening would thus be assigned to inhomogeneities in the electric potential of the plasma.
In 2021 a three-week measurement of the 83mKr N-line spectrum was performed, using a strong 10 GBq 83Rb [3] source to allow unprecedented precision. In addition, measurements with co-circulating helium and krypton were performed, which has allowed to record a reference spectrum under non-plasma conditions. In this poster we describe the measurements, the analysis and the impact on the neutrino mass result.
We acknowledge the support of Helmholtz Association (HGF); Ministry for Education and Research BMBF (05A17PM3, 05A17PX3, 05A17VK2, 05A17PDA, 05A17WO3, 05A20VK3, 05A20PMA and 05A20PX3); Helmholtz Alliance for Astroparticle Physics (HAP); the doctoral school KSETA at KIT; Helmholtz Young Investigator Group (VH-NG-1055); Max Planck Research Group (MaxPlanck@TUM); Deutsche Forschungsgemeinschaft DFG (Research Training Group grant nos. GRK 1694 and GRK 2149); Graduate School grant no. GSC 1085-KSETA, SFB-1258, and Excellence Cluster ORIGINS in Germany; Ministry of Education, Youth and Sport (CANAM-LM2015056, LTT19005) in the Czech Republic; the Department of Energy through grants DE-FG02-97ER41020, DE-FG02-94ER40818, DE-SC0004036, DE-FG02-97ER41033, DE-FG02-97ER41041, DE-SC0011091 and DE-SC0019304; and the Federal Prime Agreement DE-AC02-05CH11231 in the USA. This project has received funding from the European Research Council (ERC) under the European Union Horizon 2020 research and innovation programme (grant agreement no. 852845). We thank the computing cluster support at the Institute for Astroparticle Physics at Karlsruhe Institute of Technology, Max Planck Computing and Data Facility (MPCDF), and National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory.
[1] M. Aker, et al., Nature Physics 18, 2022, 160-166.
[2] M. Aker, et al., Journal of Instrumentation Volume 16, 2021, T08015.
[3] O. Lebeda, D. Vénos, J. Ráliš, M. Šefčík, O. Dragoun, Ultra-intense 83Rb/83mKr emanation generator for the source plasma calibration at the KATRIN experiment, this conferenc
Precision-Engineering the Pseudomonas aeruginosa Genome with Two-Step Allelic Exchange
No full textAllelic exchange is an efficient method of bacterial genome engineering. This protocol describes the use of this technique to make gene knockouts and knock-ins, as well as single-nucleotide insertions, deletions and substitutions, in Pseudomonas aeruginosa. Unlike other approaches to allelic exchange, this protocol does not require heterologous recombinases to insert or excise selective markers from the target chromosome. Rather, positive and negative selections are enabled solely by suicide vector–encoded functions and host cell proteins. Here, mutant alleles, which are flanked by regions of homology to the recipient chromosome, are synthesized in vitroand then cloned into allelic exchange vectors using standard procedures. These suicide vectors are then introduced into recipient cells by conjugation. Homologous recombination then results in antibiotic-resistant single-crossover mutants in which the plasmid has integrated site-specifically into the chromosome. Subsequently, unmarked double-crossover mutants are isolated directly using sucrose-mediated counter-selection. This two-step process yields seamless mutations that are precise to a single base pair of DNA. The entire procedure requires ~2 weeks
The role of membrane destabilisation and protein dynamics in BAM catalysed OMP folding
No full textThe folding of β-barrel outer membrane proteins (OMPs) in Gram-negative bacteria is catalysed by the β-barrel assembly machinery (BAM). How lateral opening in the β-barrel of the major subunit BamA assists in OMP folding, and the contribution of membrane disruption to BAM catalysis remain unresolved. Here, we use an anti-BamA monoclonal antibody fragment (Fab1) and two disulphide-crosslinked BAM variants (lid-locked (LL), and POTRA-5-locked (P5L)) to dissect these roles. Despite being lethal in vivo, we show that all complexes catalyse folding in vitro, albeit less efficiently than wild-type BAM. CryoEM reveals that while Fab1 and BAM-P5L trap an open-barrel state, BAM-LL contains a mixture of closed and contorted, partially-open structures. Finally, all three complexes globally destabilise the lipid bilayer, while BamA does not, revealing that the BAM lipoproteins are required for this function. Together the results provide insights into the role of BAM structure and lipid dynamics in OMP folding
Image_2_Development and Optimization of Bifunctional Fusion Proteins to Locally Modulate Complement Activation in Diseased Tissue.tif
No full textSustained complement activation is an underlying pathologic driver in many inflammatory and autoimmune diseases. Currently approved anti-complement therapies are directed at the systemic blockade of complement. Consequently, these therapies provide widespread inhibition of complement pathway activity, beyond the site of ongoing activation and the intended pharmacodynamic (PD) effects. Given the essential role for complement in both innate and adaptive immunity, there is a need for therapies that inhibit complement in diseased tissue while limiting systemic blockade. One potential approach focuses on the development of novel fusion proteins that enable tissue-targeted delivery of complement negative regulatory proteins. These therapies are expected to provide increased potency and prolonged tissue PD, decreased dosing frequency, and the potential for improved safety profiles. We created a library of bifunctional fusion proteins that direct a fragment of the complement negative regulator, complement receptor type 1 (CR1) to sites of tissue injury. Tissue targeting is accomplished through the binding of the fusion protein to complement C3 fragments that contain a surface-exposed C3d domain and which are covalently deposited on tissues where complement is being activated. To that end, we generated a fusion protein that contains an anti-C3d monoclonal antibody recombinantly linked to the first 10 consensus repeats of CR1 (CR11-10) with the intention of delivering high local concentrations of this complement negative regulatory domain to tissue-bound complement C3 fragments iC3b, C3dg and C3d. Biochemical and in vitro characterization identified several fusion proteins that inhibit complement while maintaining the C3d domain binding properties of the parent monoclonal antibody. Preclinical in vivo studies further demonstrate that anti-C3d fusion proteins effectively distribute to injured tissue and reduce C3 fragment deposition for periods beyond 14 days. The in vitro and in vivo profiles support the further evaluation of C3d mAb-CR11-10 as a novel approach to restore proper complement activation in diseased tissue in the absence of continuous systemic complement blockade.</p
A targeted boost-and-sort immunization strategy using Escherichia coli BamA identifies rare growth inhibitory antibodies
No full textAbstractOuter membrane proteins (OMPs) in Gram-negative bacteria are essential for a number of cellular functions including nutrient transport and drug efflux. Escherichia coli BamA is an essential component of the OMP β-barrel assembly machinery and a potential novel antibacterial target that has been proposed to undergo large (~15 Å) conformational changes. Here, we explored methods to isolate anti-BamA monoclonal antibodies (mAbs) that might alter the function of this OMP and ultimately lead to bacterial growth inhibition. We first optimized traditional immunization approaches but failed to identify mAbs that altered cell growth after screening >3000 hybridomas. We then developed a “targeted boost-and-sort” strategy that combines bacterial cell immunizations, purified BamA protein boosts, and single hybridoma cell sorting using amphipol-reconstituted BamA antigen. This unique workflow improves the discovery efficiency of FACS + mAbs by >600-fold and enabled the identification of rare anti-BamA mAbs with bacterial growth inhibitory activity in the presence of a truncated lipopolysaccharide layer. These mAbs represent novel tools for dissecting the BamA-mediated mechanism of β-barrel folding and our workflow establishes a new template for the efficient discovery of novel mAbs against other highly dynamic membrane proteins.</jats:p
Image_1_Development and Optimization of Bifunctional Fusion Proteins to Locally Modulate Complement Activation in Diseased Tissue.tif
No full textSustained complement activation is an underlying pathologic driver in many inflammatory and autoimmune diseases. Currently approved anti-complement therapies are directed at the systemic blockade of complement. Consequently, these therapies provide widespread inhibition of complement pathway activity, beyond the site of ongoing activation and the intended pharmacodynamic (PD) effects. Given the essential role for complement in both innate and adaptive immunity, there is a need for therapies that inhibit complement in diseased tissue while limiting systemic blockade. One potential approach focuses on the development of novel fusion proteins that enable tissue-targeted delivery of complement negative regulatory proteins. These therapies are expected to provide increased potency and prolonged tissue PD, decreased dosing frequency, and the potential for improved safety profiles. We created a library of bifunctional fusion proteins that direct a fragment of the complement negative regulator, complement receptor type 1 (CR1) to sites of tissue injury. Tissue targeting is accomplished through the binding of the fusion protein to complement C3 fragments that contain a surface-exposed C3d domain and which are covalently deposited on tissues where complement is being activated. To that end, we generated a fusion protein that contains an anti-C3d monoclonal antibody recombinantly linked to the first 10 consensus repeats of CR1 (CR11-10) with the intention of delivering high local concentrations of this complement negative regulatory domain to tissue-bound complement C3 fragments iC3b, C3dg and C3d. Biochemical and in vitro characterization identified several fusion proteins that inhibit complement while maintaining the C3d domain binding properties of the parent monoclonal antibody. Preclinical in vivo studies further demonstrate that anti-C3d fusion proteins effectively distribute to injured tissue and reduce C3 fragment deposition for periods beyond 14 days. The in vitro and in vivo profiles support the further evaluation of C3d mAb-CR11-10 as a novel approach to restore proper complement activation in diseased tissue in the absence of continuous systemic complement blockade.</p
Monoclonal antibody targeting the β-barrel assembly machine of <i>Escherichia coli</i> is bactericidal
No full textSignificance
The outer membrane of Gram-negative bacteria presents a formidable barrier to the discovery of new antibiotics needed to combat infections by multidrug-resistant bacteria. Targeting essential proteins or processes directly exposed to the environment could bypass this obstacle. Here, we describe a monoclonal antibody that selectively and potently antagonizes BamA, which folds and inserts integral outer membrane β-barrel proteins, by binding to a surface-exposed BamA epitope and, as a result, inhibits bacterial cell growth. Mechanisms of resistance to the antibody reveal that membrane fluidity affects BamA activity. This antibody validates the potential therapeutic strategy of targeting essential, exposed functions and provides a powerful tool for dissecting the fundamental process of folding integral membrane β-barrel proteins in vivo.</jats:p
