45 research outputs found

    Molecular Genetic Abnormalities in the Pathogenesis of Hematologic Malignancies and Corresponding Changes in Cell Signaling Systems

    Get PDF
    Hematological disorders include a wide spectrum of malignancies of hematopoietic and lymphoid tissues. The genetic changes underlying the pathogenesis of the diseases are specific for each disease. High incidence of chromosomal aberrations (deletion, translocation, insertion) is one of the principal characteristics of oncohematological diseases. In addition, mutations in individual genes or blocking of normal regulation of gene functioning in relation to epigenetic events can occur. Progression of oncohematological diseases could be a result of accumulation of different genetic abnormalities. Modern classification of malignancies of hematopoietic and lymphoid tissues is based on the analysis of clinical data, morphological and functional characteristics of tumor cells and identification of specific cytogenetic and molecular-genetic changes. A large number of genetic abnormalities specific for certain types of hematological malignancies has been discovered to date. It allows to optimize the treatment strategy, as well as to design, test and introduce to the clinical practice a number of targeted drugs (inhibitors of chimeric proteins formed as a result of translocations and triggering the malignant cell transformation). Drugs based on monoclonal antibodies (Rituximab, Alemtuzumab, etc.) or low molecular weight compounds (Imatinib, Bortezomib, Carfilzomib) form this group of medications. The knowledge about not only specific gene abnormalities but also about the corresponding changes in cell efferent signaling pathways could be of great interest for the development of new targeted molecules or the repurposing of known chemotherapeutic agents. The present review compares genetic aberrations in diseases listed in the 2008 WHO classification (amended in 2016) of hematopoietic and lymphoid tissue malignancies and main changes in cell signaling pathways associated with malignant transformation of hematopoietic cells

    Structural and electronic determinants of lytic polysaccharide monooxygenase reactivity on polysaccharide substrates

    Get PDF
    Lytic polysaccharide monooxygenases (LPMOs) are industrially important copper-dependent enzymes that oxidatively cleave polysaccharides. Here we present a functional and structural characterization of two closely related AA9-family LPMOs from Lentinus similis (LsAA9A) and Collariella virescens (CvAA9A). LsAA9A and CvAA9A cleave a range of polysaccharides, including cellulose, xyloglucan, mixed-linkage glucan and glucomannan. LsAA9A additionally cleaves isolated xylan substrates. The structures of CvAA9A and of LsAA9A bound to cellulosic and non-cellulosic oligosaccharides provide insight into the molecular determinants of their specificity. Spectroscopic measurements reveal differences in copper co-ordination upon the binding of xylan and glucans. LsAA9A activity is less sensitive to the reducing agent potential when cleaving xylan, suggesting that distinct catalytic mechanisms exist for xylan and glucan cleavage. Overall, these data show that AA9 LPMOs can display different apparent substrate specificities dependent upon both productive protein–carbohydrate interactions across a binding surface and also electronic considerations at the copper active site

    The molecular basis of polysaccharide cleavage by lytic polysaccharide monooxygenases.

    Get PDF
    Lytic polysaccharide monooxygenases (LPMOs) are copper-containing enzymes that oxidatively break down recalcitrant polysaccharides such as cellulose and chitin. Since their discovery, LPMOs have become integral factors in the industrial utilization of biomass, especially in the sustainable generation of cellulosic bioethanol. We report here a structural determination of an LPMO-oligosaccharide complex, yielding detailed insights into the mechanism of action of these enzymes. Using a combination of structure and electron paramagnetic resonance spectroscopy, we reveal the means by which LPMOs interact with saccharide substrates. We further uncover electronic and structural features of the enzyme active site, showing how LPMOs orchestrate the reaction of oxygen with polysaccharide chains.We thank K. Rasmussen and R.M. Borup for experimental assistance, and MAXLAB, Sweden and the European Synchrotron Radiation Facility (ESRF), France, for synchrotron beam time and assistance. This work was supported by the UK Biotechnology and Biological Sciences Research Council (grant numbers BB/L000423 to P.D., G.J.D. and P.H.W., and BB/L021633/1 to G.J.D. and P.H.W.), Agence Française de l'Environnement et de la Maîtrise de l'Energie (grant number 1201C102 to B.H.), the Danish Council for Strategic Research (grant numbers 12-134923 to L.L.L. and 12-134922 to K.S.J.). Travel to synchrotrons was supported by the Danish Ministry of Higher Education and Science through the Instrument Center DANSCATT and the European Community's Seventh Framework Programme (FP7/2007-2013) under BioStruct-X (grant agreement 283570). L.M., S.F., S.C. and H.D. were supported by Institut de Chimie Moléculaire de Grenoble FR 2607, LabEx ARCANE (ANR-11-LABX-0003-01), the PolyNat Carnot Institute and the French Agence Nationale de la Recherche (PNRB2005-11).This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nchembio.202

    The Eurasian Modern Pollen Database (EMPD), version 2

    Get PDF
    Abstract. The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).</jats:p

    Immunoglobulin, glucocorticoid, or combination therapy for multisystem inflammatory syndrome in children: a propensity-weighted cohort study

    Get PDF
    Background Multisystem inflammatory syndrome in children (MIS-C), a hyperinflammatory condition associated with SARS-CoV-2 infection, has emerged as a serious illness in children worldwide. Immunoglobulin or glucocorticoids, or both, are currently recommended treatments. Methods The Best Available Treatment Study evaluated immunomodulatory treatments for MIS-C in an international observational cohort. Analysis of the first 614 patients was previously reported. In this propensity-weighted cohort study, clinical and outcome data from children with suspected or proven MIS-C were collected onto a web-based Research Electronic Data Capture database. After excluding neonates and incomplete or duplicate records, inverse probability weighting was used to compare primary treatments with intravenous immunoglobulin, intravenous immunoglobulin plus glucocorticoids, or glucocorticoids alone, using intravenous immunoglobulin as the reference treatment. Primary outcomes were a composite of inotropic or ventilator support from the second day after treatment initiation, or death, and time to improvement on an ordinal clinical severity scale. Secondary outcomes included treatment escalation, clinical deterioration, fever, and coronary artery aneurysm occurrence and resolution. This study is registered with the ISRCTN registry, ISRCTN69546370. Findings We enrolled 2101 children (aged 0 months to 19 years) with clinically diagnosed MIS-C from 39 countries between June 14, 2020, and April 25, 2022, and, following exclusions, 2009 patients were included for analysis (median age 8·0 years [IQR 4·2–11·4], 1191 [59·3%] male and 818 [40·7%] female, and 825 [41·1%] White). 680 (33·8%) patients received primary treatment with intravenous immunoglobulin, 698 (34·7%) with intravenous immunoglobulin plus glucocorticoids, 487 (24·2%) with glucocorticoids alone; 59 (2·9%) patients received other combinations, including biologicals, and 85 (4·2%) patients received no immunomodulators. There were no significant differences between treatments for primary outcomes for the 1586 patients with complete baseline and outcome data that were considered for primary analysis. Adjusted odds ratios for ventilation, inotropic support, or death were 1·09 (95% CI 0·75–1·58; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids and 0·93 (0·58–1·47; corrected p value=1·00) for glucocorticoids alone, versus intravenous immunoglobulin alone. Adjusted average hazard ratios for time to improvement were 1·04 (95% CI 0·91–1·20; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids, and 0·84 (0·70–1·00; corrected p value=0·22) for glucocorticoids alone, versus intravenous immunoglobulin alone. Treatment escalation was less frequent for intravenous immunoglobulin plus glucocorticoids (OR 0·15 [95% CI 0·11–0·20]; p<0·0001) and glucocorticoids alone (0·68 [0·50–0·93]; p=0·014) versus intravenous immunoglobulin alone. Persistent fever (from day 2 onward) was less common with intravenous immunoglobulin plus glucocorticoids compared with either intravenous immunoglobulin alone (OR 0·50 [95% CI 0·38–0·67]; p<0·0001) or glucocorticoids alone (0·63 [0·45–0·88]; p=0·0058). Coronary artery aneurysm occurrence and resolution did not differ significantly between treatment groups. Interpretation Recovery rates, including occurrence and resolution of coronary artery aneurysms, were similar for primary treatment with intravenous immunoglobulin when compared to glucocorticoids or intravenous immunoglobulin plus glucocorticoids. Initial treatment with glucocorticoids appears to be a safe alternative to immunoglobulin or combined therapy, and might be advantageous in view of the cost and limited availability of intravenous immunoglobulin in many countries. Funding Imperial College London, the European Union's Horizon 2020, Wellcome Trust, the Medical Research Foundation, UK National Institute for Health and Care Research, and National Institutes of Health

    Ion Gyro‐Harmonic Structures in Stimulated Emission Excited by X‐Mode High Power HF Radio Waves at EISCAT

    Full text link
    The distinctive features of the ion gyro-harmonic discrete structures in the narrowband stimulated electromagnetic emission (NSEE) spectra (within ±1 kHz of the heater frequency), excited by an extraordinary (X-mode) polarized high frequency (HF) pump wave in the F-region of the high latitude ionosphere, are reported. Results were obtained from three sets of experiments at the EISCAT (European incoherent Scatter) HF Heating facility at pump frequencies of 5.423, 6.77 and 7.953 MHz, which are below the fourth, fifth, and sixth electron gyro-harmonics. High power HF radio waves were radiated in the magnetic field-aligned direction with an effective radiated power of 238–740 MW. Discrete spectral features, ordered by the ion gyro frequency (for O+ ions), were recorded at a large distance (1,200 km) away from the Heating facility. Up to 10 downshifted discrete ion gyro-harmonic structures paired with the upshifted spectral components (Stokes and anti-Stokes modes) in the NSEE spectra have been excited in the course of these experiments. It was found that preconditioning effects have a significant impact on the temporal evolution of the discrete spectral structures. The ion gyro-harmonic structures coexisted with field-aligned artificial irregularities (FAIs). Comparing the NSEE and EISCAT incoherent scatter radar observational results, it was concluded that the electron accelerations along and across the geomagnetic field coexist during X-mode heating. The magnetized stimulated Brillouin scatter and stimulated ion Bernstein scatter are discussed as relevant processes for the observed multiple down- and upshifted ion gyro-harmonic structures in the NSEE spectra.Plain Language SummaryExperiments in the Earth's ionosphere (part of the upper atmosphere) using high power high frequency (HF, or shortwave) radio waves may be used to study a wide variety of fundamental phenomena. We discuss recent advances in observations of stimulated radio emissions generated by a powerful HF radio transmitter at the European incoherent Scatter observatory in northern Norway. We found that the high power HF wave is able to generate radio emissions that can be observed more than one thousand kilometers away, in Saint Petersburg, Russia. We found and investigated distinctive frequencies of the radio emissions, and we believe, based on past results, that such emissions are not observable from locations close to the radio transmitter. The emissions we observed can be exploited for diagnostics of the Earth's environment, and they are similar to emissions seen in laser interactions with ionized gases such as occur in laser fusion experiments, and also in piezoelectric semiconductor devices, in fiber optics, and in many biological systems. This opens a window for utilizing our results to assist in these and other related areas.</div

    Distinctive Features of Langmuir and Ion‐Acoustic Turbulences Induced by O‐ and X‐Mode HF Pumping at EISCAT

    No full text
    We report experimental results regarding the distinctive features and behaviors of high‐frequency (HF)‐induced Langmuir and ion‐acoustic turbulences induced by ordinary (O‐mode) and extraordinary (X‐mode) polarized powerful HF radio waves injected into the high‐latitude ionosphere F region toward the magnetic zenith at EISCAT (European Incoherent SCATter). Alternating O‐/X‐mode pumping was produced at high heater frequencies in the range fH = 6–8 MHz during magnetically quiet background geophysical conditions. An effective radiated power of 450–600 MW was utilized. The radical distinction between the temporal evolution of the O‐ and X‐mode Langmuir and ion‐acoustic plasma waves after the HF heater is switched on in conjunction with the development of artificial field‐aligned irregularities (FAIs) was analyzed. It was found that the excitation thresholds of the Langmuir and ion‐acoustic turbulences significantly differed for the O‐ and X‐mode HF pumping. We have revealed that the X‐mode excitation thresholds for HF‐induced plasma and ion line backscatter are 0.47 and 0.61 V/m, respectively. The persistent O‐mode plasma and ion line backscatters that coexisted with FAIs showed excitation thresholds of 0.62 and 0.73 V/m, respectively, which exceeded the thresholds for the X‐mode plasma and ion lines, while their intensity was 2 orders of magnitude less. For the same background conditions, the “classic” resonance parametric decay instability and modulation instability, excited as the momentary response to the O‐mode HF pump wave switching on (the so‐called overshoot), have thresholds of 0.17 and 0.25 V/m, respectively, which are much below the excitation thresholds of persistent O‐mode plasma and ion lines

    Open-label phase II clinical trial in 75 patients with advanced hepatocellular carcinoma receiving daily dose of tableted liver cancer vaccine, hepcortespenlisimut-L

    No full text
    Marina G Tarakanovskaya,1 Jigjidsuren Chinburen,2 Purev Batchuluun,2 Chogsom Munkhzaya,2 Genden Purevsuren,2 Dorjiin Dandii,3 Tsogkhuu Hulan,3 Dandii Oyungerel,4 Galyna A Kutsyna,5 Alan A Reid,6 Vika Borisova,6 Allen I Bain,7 Vichai Jirathitikal,7 Aldar S Bourinbaiar6&ndash;8 1Ekomed LLC, 2National Cancer Center, 3Monserum LLC, 4National Center for Public Health, Ulaanbaatar, Mongolia; 5Department of Infectious Diseases, Luhansk State Medical University, Luhansk, Ukraine; 6Immunitor China Ltd, Beijing, People&rsquo;s Republic of China; 7Immunitor Inc, Vancouver, BC, Canada; 8Immunitor LLC, Ulaanbaatar, Mongolia Background: An increasing number of studies is now devoted to immunotherapy of cancer. We evaluated the clinical benefit of hepcortespenlisimut-L (Hepko-V5 [formerly known as V5])&mdash;an oral therapeutic vaccine designated by the United States Food and Drug Administration (FDA) as an orphan drug for treatment of hepatocellular carcinoma (HCC). V5 was initially developed by us in 2002 to treat hepatitis B or C viral infections and liver cirrhosis.Methods: The outcome of open-label Phase II trial of daily dose of V5 pill was analyzed retrospectively. Over a period of 5 years, 75 patients with advanced HCC were enrolled, consisting of 29 (38.7%) females and 46 (61.3%) males with a median age of 60 years (mean 61.6&plusmn;8.1 years). Out of these, 23 (30.7%) had hepatitis B and 34 (45.3%) had hepatitis C infections, including 9 (12%) with dual infection, 4 (5.3%) negative for both viruses, and 5 (6.7%) without established viral diagnosis. Most patients (94.7%) had underlying liver cirrhosis of varying severity.Results: After a median of 2 months of treatment, 50 out of 75 patients had experienced a decline in serum levels of the tumor marker, alpha-fetoprotein (AFP) (66.7%; P=0.006 by Wilcoxon signed rank test). Baseline median AFP levels were 245.2 IU/mL (mean 4,233; range 7.2&ndash;92,407; 95% confidence interval [CI] 1,186&ndash;7,280) and post-treatment values were 102.3 IU/mL (mean 2,539; range 0.9&ndash;54,478; 95% CI 503&ndash;4,575). The decrease in AFP was correlated either with tumor clearance or regression on computed tomography scans. The median overall survival time could not be established since 68 out of 75 (90.7%) patients were still alive after median follow-up of 12 months (mean 15&plusmn;9.7; range 7&ndash;59; 95% CI 12.8&ndash;17.2). The first patient in this study received immunotherapy 5 years ago and still remains in complete remission. None of the patients experienced any serious adverse effects or toxicity.Conclusion: The results indicate that hepcortespenlismut-L is a safe, effective, and fast-acting immunomodulatory intervention for HCC. The Phase III, randomized, double-blind, placebo-controlled trial is now initiated at the Mongolian National Cancer Center to confirm these promising findings. Keywords: allogeneic, inflammation, immune toleranc
    corecore