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Vymola P, Garcia-Borja E, Cervenka J, Balaziova E, Vymolova B, Veprkova J, Vodicka P, Skalnikova H, Tomas R, Netuka D, Busek P, Sedo A. Fibrillar extracellular matrix produced by pericyte-like cells facilitates glioma cell dissemination. Brain Pathol 2024:e13265. [PMID: 38705944 DOI: 10.1111/bpa.13265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/16/2024] [Indexed: 05/07/2024] Open
Abstract
Gliomagenesis induces profound changes in the composition of the extracellular matrix (ECM) of the brain. In this study, we identified a cellular population responsible for the increased deposition of collagen I and fibronectin in glioblastoma. Elevated levels of the fibrillar proteins collagen I and fibronectin were associated with the expression of fibroblast activation protein (FAP), which is predominantly found in pericyte-like cells in glioblastoma. FAP+ pericyte-like cells were present in regions rich in collagen I and fibronectin in biopsy material and produced substantially more collagen I and fibronectin in vitro compared to other cell types found in the GBM microenvironment. Using mass spectrometry, we demonstrated that 3D matrices produced by FAP+ pericyte-like cells are rich in collagen I and fibronectin and contain several basement membrane proteins. This expression pattern differed markedly from glioma cells. Finally, we have shown that ECM produced by FAP+ pericyte-like cells enhances the migration of glioma cells including glioma stem-like cells, promotes their adhesion, and activates focal adhesion kinase (FAK) signaling. Taken together, our findings establish FAP+ pericyte-like cells as crucial producers of a complex ECM rich in collagen I and fibronectin, facilitating the dissemination of glioma cells through FAK activation.
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Affiliation(s)
- Petr Vymola
- Laboratory of Cancer Cell Biology, Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Elena Garcia-Borja
- Laboratory of Cancer Cell Biology, Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jakub Cervenka
- Laboratory of Applied Proteome Analyses, Research Center PIGMOD, Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Liběchov, Czech Republic
- Laboratory of proteomics, Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Eva Balaziova
- Laboratory of Cancer Cell Biology, Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Barbora Vymolova
- Laboratory of Cancer Cell Biology, Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jana Veprkova
- Laboratory of Cancer Cell Biology, Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Petr Vodicka
- Laboratory of Applied Proteome Analyses, Research Center PIGMOD, Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Liběchov, Czech Republic
| | - Helena Skalnikova
- Laboratory of Applied Proteome Analyses, Research Center PIGMOD, Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Liběchov, Czech Republic
- Laboratory of proteomics, Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Robert Tomas
- Department of Neurosurgery, Na Homolce Hospital, Prague, Czech Republic
| | - David Netuka
- Department of Neurosurgery and Neurooncology, First Faculty of Medicine, Charles University and Military University Hospital, Prague, Czech Republic
| | - Petr Busek
- Laboratory of Cancer Cell Biology, Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Aleksi Sedo
- Laboratory of Cancer Cell Biology, Institute of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
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Premus J, Gallovič F, Ampuero JP. Bridging time scales of faulting: From coseismic to postseismic slip of the Mw 6.0 2014 South Napa, California earthquake. Sci Adv 2022; 8:eabq2536. [PMID: 36149958 PMCID: PMC9506709 DOI: 10.1126/sciadv.abq2536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/04/2022] [Indexed: 05/31/2023]
Abstract
Transient fault slip spans time scales from tens of seconds of earthquake rupture to years of aseismic afterslip. So far, seismic and geodetic recordings of these two phenomena have primarily been studied separately and mostly with a focus on kinematic aspects, which limits our physical understanding of the interplay between seismic and aseismic slip. Here, we use a Bayesian dynamic source inversion method, based on laboratory-derived friction laws, to constrain fault stress and friction properties by joint quantitative modeling of coseismic and postseismic observations. Analysis of the well-recorded 2014 South Napa, California earthquake shows how the stressing and frictional conditions on the fault govern the spatial separation between shallow coseismic and postseismic slip, the progression of afterslip driving deep off-fault aftershocks, and the oblique ribbon-like rupture shape. Such inferences of stress and frictional rheology can advance our understanding of earthquake physics and pave the way for self-consistent cross-scale seismic hazard assessment.
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Affiliation(s)
- Jan Premus
- Department of Geophysics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - František Gallovič
- Department of Geophysics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - Jean-Paul Ampuero
- Université Côte d’Azur, IRD, CNRS, Observatoire de la Côte d’Azur, Géoazur, France
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Wang Z, Reticcioli M, Jakub Z, Sokolović I, Meier M, Boatner LA, Schmid M, Parkinson GS, Diebold U, Franchini C, Setvin M. Surface chemistry on a polarizable surface: Coupling of CO with KTaO 3(001). Sci Adv 2022; 8:eabq1433. [PMID: 35984882 PMCID: PMC9390988 DOI: 10.1126/sciadv.abq1433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Polarizable materials attract attention in catalysis because they have a free parameter for tuning chemical reactivity. Their surfaces entangle the dielectric polarization with surface polarity, excess charge, and orbital hybridization. How this affects individual adsorbed molecules is shown for the incipient ferroelectric perovskite KTaO3. This intrinsically polar material cleaves along (001) into KO- and TaO2-terminated surface domains. At TaO2 terraces, the polarity-compensating excess electrons form a two-dimensional electron gas and can also localize by coupling to ferroelectric distortions. TaO2 terraces host two distinct types of CO molecules, adsorbed at equivalent lattice sites but charged differently as seen in atomic force microscopy/scanning tunneling microscopy. Temperature-programmed desorption shows substantially stronger binding of the charged CO; in density functional theory calculations, the excess charge favors a bipolaronic configuration coupled to the CO. These results pinpoint how adsorption states couple to ferroelectric polarization.
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Affiliation(s)
- Zhichang Wang
- Institute of Applied Physics, TU Wien, Vienna, Austria
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Michele Reticcioli
- Faculty of Physics and Center for Computational Materials Science, University of Vienna, Vienna, Austria
| | - Zdenek Jakub
- Institute of Applied Physics, TU Wien, Vienna, Austria
| | | | | | - Lynn A. Boatner
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | | | | | | | - Cesare Franchini
- Faculty of Physics and Center for Computational Materials Science, University of Vienna, Vienna, Austria
- Dipartimento di Fisica e Astronomia, Universita di Bologna, 40127 Bologna, Italy
| | - Martin Setvin
- Institute of Applied Physics, TU Wien, Vienna, Austria
- Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, 180 00 Prague 8, Czech Republic
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Chalupa R, Nesměrák K. Chemophobia and passion: why chemists should desire Marcel Proust. Monatsh Chem 2022; 153:697-705. [PMID: 35855688 PMCID: PMC9281275 DOI: 10.1007/s00706-022-02945-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 06/06/2022] [Indexed: 10/27/2022]
Abstract
In this article, we introduce a new communication strategy called the "communication success dimension" for the suppression and eradication of chemophobia. We explain, using recent examples, that chemophobia presents a danger not only to the science of chemistry but also to humankind. Based on the latest insights from communication research, we emphasize the need to bring more passion, dedication, and human factors into the communication of chemistry. We demonstrate the application of this new strategy by employing Marcel Proust's In Search of Lost Time to combat chemophobia. Graphical abstract
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Affiliation(s)
- Radek Chalupa
- Department of Teaching and Didactics of Chemistry, Faculty of Science, Charles University, Prague, Czech Republic
- RCC Europe, Ltd., Prague, Czech Republic
| | - Karel Nesměrák
- Department of Analytical Chemistry, Faculty of Science, Charles University, Prague, Czech Republic
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Policht VR, Niedringhaus A, Willow R, Laible PD, Bocian DF, Kirmaier C, Holten D, Mančal T, Ogilvie JP. Hidden vibronic and excitonic structure and vibronic coherence transfer in the bacterial reaction center. Sci Adv 2022; 8:eabk0953. [PMID: 34985947 PMCID: PMC8730630 DOI: 10.1126/sciadv.abk0953] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We report two-dimensional electronic spectroscopy (2DES) experiments on the bacterial reaction center (BRC) from purple bacteria, revealing hidden vibronic and excitonic structure. Through analysis of the coherent dynamics of the BRC, we identify multiple quasi-resonances between pigment vibrations and excitonic energy gaps, and vibronic coherence transfer processes that are typically neglected in standard models of photosynthetic energy transfer and charge separation. We support our assignment with control experiments on bacteriochlorophyll and simulations of the coherent dynamics using a reduced excitonic model of the BRC. We find that specific vibronic coherence processes can readily reveal weak exciton transitions. While the functional relevance of such processes is unclear, they provide a spectroscopic tool that uses vibrations as a window for observing excited state structure and dynamics elsewhere in the BRC via vibronic coupling. Vibronic coherence transfer reveals the upper exciton of the “special pair” that was weakly visible in previous 2DES experiments.
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Affiliation(s)
- Veronica R. Policht
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Andrew Niedringhaus
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Rhiannon Willow
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Philip D. Laible
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - David F. Bocian
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Tomáš Mančal
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-12116 Prague 2, Czech Republic
| | - Jennifer P. Ogilvie
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
- Corresponding author.
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Stepankova L, Kralikova E, Zvolska K, Pankova A, Ovesna P, Blaha M, Brose LS. Depression and Smoking Cessation: Evidence from a Smoking Cessation Clinic with 1-Year Follow-Up. Ann Behav Med 2017; 51:454-463. [PMID: 28035641 PMCID: PMC5440483 DOI: 10.1007/s12160-016-9869-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Smoking is more prevalent among people with depression. Depression may make cessation more difficult and cessation may affect depression symptoms. PURPOSE The aims of this study were to assess the associations between (1) baseline depression and 1-year smoking abstinence and (2) abstinence and change in depression. METHODS Observational study using data collected routinely in a smoking cessation clinic in the Czech Republic from 2008 to 2014. Aim 1: N = 3775 patients; 14.3% reported mild and 15.4% moderate/severe baseline depression levels measured using Beck's Depression Inventory (BDI-II). Logistic regressions assessed if depression level predicted 1-year biochemically verified abstinence while adjusting for patient and treatment characteristics. Aim 2: N = 835 patients abstinent at 1 year; change in depression was analysed using Chi-square statistics, t test and mixed method analyses of variance. RESULTS Rate of abstinence was lower for patients with mild (32.5%, OR = 0.68; 95% CI: 0.54 to 0.87, p = 0.002) and moderate/severe depression (25.8%; OR = 0.57, 95% CI: 0.45 to 0.74, p < 0.001) compared with patients without depression (40.5%). Across abstinent patients, the majority with baseline depression reported lower depression levels at follow-up. Overall mean (SD) BDI-II scores improved from 9.2 (8.6) to 5.3 (6.1); t(834) = 14.6, p < 0.001. There were significant main effects of time (F(1832) = 880.8, p < 0.001, partial η2 = 0.51) and baseline depression level (F(2832) = 666.4, p < 0.001, partial η2 = 0.62) on follow-up depression and a significant depression * time interaction (F(2832) = 296.5, p < 0.001, partial η2 = 0.42). CONCLUSIONS In this effective smoking cessation clinic, depression at the start of treatment predicted reduced smoking abstinence 1 year later. Patients abstinent from smoking experienced considerable improvement in depression.
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Affiliation(s)
- Lenka Stepankova
- Center for Tobacco-Dependent of the 3rd Medical Department—Department of Endocrinology and Metabolism, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Karlovo namesti 32, 128 00 Praha 2, Czech Republic
| | - Eva Kralikova
- Center for Tobacco-Dependent of the 3rd Medical Department—Department of Endocrinology and Metabolism, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Karlovo namesti 32, 128 00 Praha 2, Czech Republic
- Institute of Hygiene and Epidemiology, First Faculty of Medicine, Charles University and General University Hospital Prague, Studničkova 7, 128 00 Praha 2, Czech Republic
| | - Kamila Zvolska
- Center for Tobacco-Dependent of the 3rd Medical Department—Department of Endocrinology and Metabolism, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Karlovo namesti 32, 128 00 Praha 2, Czech Republic
| | - Alexandra Pankova
- Center for Tobacco-Dependent of the 3rd Medical Department—Department of Endocrinology and Metabolism, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Karlovo namesti 32, 128 00 Praha 2, Czech Republic
- Institute of Hygiene and Epidemiology, First Faculty of Medicine, Charles University and General University Hospital Prague, Studničkova 7, 128 00 Praha 2, Czech Republic
| | - Petra Ovesna
- Institute of Biostatistics and Analyses at the Faculty of Medicine and the Faculty of Science, Masaryk University, Kamenice 126/3, 625 00 Brno, Czech Republic
| | - Milan Blaha
- Institute of Biostatistics and Analyses at the Faculty of Medicine and the Faculty of Science, Masaryk University, Kamenice 126/3, 625 00 Brno, Czech Republic
| | - Leonie S Brose
- Psychology and Neuroscience, King’s College London, UK and UK Centre for Tobacco and Alcohol Studies, Institute of Psychiatry, Addictions Sciences Building, 4 Windsor Walk, Denmark Hill, SE5 8BB London, UK
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Řimnáčová J, Mikeš L, Turjanicová L, Bulantová J, Horák P. Changes in surface glycosylation and glycocalyx shedding in Trichobilharzia regenti (Schistosomatidae) during the transformation of cercaria to schistosomulum. PLoS One 2017; 12:e0173217. [PMID: 28296924 PMCID: PMC5351870 DOI: 10.1371/journal.pone.0173217] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 02/17/2017] [Indexed: 11/25/2022] Open
Abstract
The invasive larvae (cercariae) of schistosomes penetrate the skin of their definitive hosts. During the invasion, they undergo dramatic ultrastructural and physiological transitions. These changes result in the development of the subsequent stage, schistosomulum, which migrates through host tissues in close contact with host's immune system. One of the striking changes in the transforming cercariae is the shedding of their thick tegumental glycocalyx, which represents an immunoattractive structure; therefore its removal helps cercariae to avoid immune attack. A set of commercial fluorescently labeled lectin probes, their saccharide inhibitors and monoclonal antibodies against the trisaccharide Lewis-X antigen (LeX, CD15) were used to characterize changes in the surface saccharide composition of the neuropathogenic avian schistosome Trichobilharzia regenti during the transformation of cercariae to schistosomula, both in vitro and in vivo. The effect of various lectins on glycocalyx shedding was evaluated microscopically. The involvement of peptidases and their inhibitors on the shedding of glycocalyx was investigated using T. regenti recombinant cathepsin B2 and a set of peptidase inhibitors. The surface glycocalyx of T. regenti cercariae was rich in fucose and mannose/glucose residues. After the transformation of cercariae in vitro or in vivo within their specific duck host, reduction and vanishing of these epitopes was observed, and galactose/N-acetylgalactosamine emerged. The presence of LeX was not observed on the cercariae, but the antigen was gradually expressed from the anterior part of the body in the developing schistosomula. Some lectins which bind to the cercarial surface also induced secretion from the acetabular penetration glands. Seven lectins induced the shedding of glycocalyx by cercariae, among which five bound strongly to cercarial surface; the effect could be blocked by saccharide inhibitors. Mannose-binding protein, part of the lectin pathway of the complement system, also bound to cercariae and schistosomula, but had little effect on glycocalyx shedding. Our study did not confirm the involvement of proteolysis in glycocalyx shedding.
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Affiliation(s)
- Jana Řimnáčová
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague 2, Czech Republic
| | - Libor Mikeš
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague 2, Czech Republic
| | - Libuše Turjanicová
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague 2, Czech Republic
| | - Jana Bulantová
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague 2, Czech Republic
| | - Petr Horák
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague 2, Czech Republic
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Heneberg P, Dolinay M, Matušík H, Pfeiffer T, Nachtigall W, Bizos J, Šimčíková D, Literák I. Conservation of the Red Kite Milvus milvus (Aves: Accipitriformes) Is Not Affected by the Establishment of a Broad Hybrid Zone with the Black Kite Milvus migrans migrans in Central Europe. PLoS One 2016; 11:e0159202. [PMID: 27463515 PMCID: PMC4962980 DOI: 10.1371/journal.pone.0159202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 06/28/2016] [Indexed: 11/19/2022] Open
Abstract
Among Accipitriformes sensu stricto, only a few species have been reported to form hybrid zones; these include the red kite Milvus milvus and black kite Milvus migrans migrans. M. milvus is endemic to the western Palearctic and has an estimated total population of 20-24,000 breeding pairs. The species was in decline until the 1970s due to persecution and has declined again since the 1990s due to ingestion of rodenticide-treated baits, illegal poisoning and changes in agricultural practices, particularly in its core range. Whereas F1 M. milvus × M. migr. migrans hybrid offspring have been found, F2 and F3 hybrids have only rarely been reported, with low nesting success rates of F1 hybrids and partial hybrid sterility likely playing a role. Here, we analyzed the mitochondrial (CO1 and CytB) and nuclear (Myc) DNA loci of 184 M. milvus, 124 M. migr. migrans and 3 F1 hybrid individuals collected across central Europe. In agreement with previous studies, we found low heterozygosity in M. milvus regardless of locus. We found that populations of both examined species were characterized by a high gene flow within populations, with all of the major haplotypes distributed across the entire examined area. Few haplotypes displayed statistically significant aggregation in one region over another. We did not find mitochondrial DNA of one species in individuals with the plumage of the other species, except in F1 hybrids, which agrees with Haldane´s Rule. It remains to be investigated by genomic methods whether occasional gene flow occurs through the paternal line, as the examined Myc gene displayed only marginal divergence between M. milvus and M. migr. migrans. The central European population of M. milvus is clearly subject to free intraspecific gene flow, which has direct implications when considering the origin of individuals in M. milvus re-introduction programs.
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Affiliation(s)
- Petr Heneberg
- Charles University in Prague, Third Faculty of Medicine, Prague, Czech Republic
- * E-mail:
| | - Matej Dolinay
- Masaryk University, Faculty of Science, Department of Botany and Zoology, Brno, Czech Republic
| | - Hynek Matušík
- Czech Society for Ornithology, Working Group for Protection and Research of Raptors and Owls, Březolupy, Czech Republic
| | | | - Winfried Nachtigall
- Förderverein Sächsische Vogelschutzwarte Neschwitz e. V., Neschwitz, Germany
| | - Jiří Bizos
- Charles University in Prague, Third Faculty of Medicine, Prague, Czech Republic
| | - Daniela Šimčíková
- Charles University in Prague, Third Faculty of Medicine, Prague, Czech Republic
| | - Ivan Literák
- University of Veterinary and Pharmaceutical Sciences Brno, Faculty of Veterinary Hygiene and Ecology, Department of Biology and Wildlife Diseases, Brno, Czech Republic
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Stochl J, Böhnke JR, Pickett KE, Croudace TJ. An evaluation of computerized adaptive testing for general psychological distress: combining GHQ-12 and Affectometer-2 in an item bank for public mental health research. BMC Med Res Methodol 2016; 16:58. [PMID: 27206714 PMCID: PMC4875708 DOI: 10.1186/s12874-016-0158-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 05/10/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recent developments in psychometric modeling and technology allow pooling well-validated items from existing instruments into larger item banks and their deployment through methods of computerized adaptive testing (CAT). Use of item response theory-based bifactor methods and integrative data analysis overcomes barriers in cross-instrument comparison. This paper presents the joint calibration of an item bank for researchers keen to investigate population variations in general psychological distress (GPD). METHODS Multidimensional item response theory was used on existing health survey data from the Scottish Health Education Population Survey (n = 766) to calibrate an item bank consisting of pooled items from the short common mental disorder screen (GHQ-12) and the Affectometer-2 (a measure of "general happiness"). Computer simulation was used to evaluate usefulness and efficacy of its adaptive administration. RESULTS A bifactor model capturing variation across a continuum of population distress (while controlling for artefacts due to item wording) was supported. The numbers of items for different required reliabilities in adaptive administration demonstrated promising efficacy of the proposed item bank. CONCLUSIONS Psychometric modeling of the common dimension captured by more than one instrument offers the potential of adaptive testing for GPD using individually sequenced combinations of existing survey items. The potential for linking other item sets with alternative candidate measures of positive mental health is discussed since an optimal item bank may require even more items than these.
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Affiliation(s)
- Jan Stochl
- Department of Health Sciences, University of York, York, UK.
- Department of Psychiatry, University of Cambridge, Cambridge Biomedical Campus, Box 189, Cambridge, CB2 0QQ, UK.
- Department of Kinanthropology, Charles University, Prague, Czech Republic.
| | - Jan R Böhnke
- Department of Health Sciences, University of York, York, UK
- Hull York Medical School (HYMS), University of York, York, UK
| | - Kate E Pickett
- Department of Health Sciences, University of York, York, UK
| | - Tim J Croudace
- Department of Health Sciences, University of York, York, UK
- Hull York Medical School (HYMS), University of York, York, UK
- Dundee Centre for Health And Related Research, School of Nursing & Health Sciences, University of Dundee and Academic Health Science Partnership Tayside, Dundee, UK
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10
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Heneberg P. From Excessive Journal Self-Cites to Citation Stacking: Analysis of Journal Self-Citation Kinetics in Search for Journals, Which Boost Their Scientometric Indicators. PLoS One 2016; 11:e0153730. [PMID: 27088862 PMCID: PMC4835057 DOI: 10.1371/journal.pone.0153730] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/01/2016] [Indexed: 11/19/2022] Open
Abstract
Bibliometric indicators increasingly affect careers, funding, and reputation of individuals, their institutions and journals themselves. In contrast to author self-citations, little is known about kinetics of journal self-citations. Here we hypothesized that they may show a generalizable pattern within particular research fields or across multiple fields. We thus analyzed self-cites to 60 journals from three research fields (multidisciplinary sciences, parasitology, and information science). We also hypothesized that the kinetics of journal self-citations and citations received from other journals of the same publisher may differ from foreign citations. We analyzed the journals published the American Association for the Advancement of Science, Nature Publishing Group, and Editura Academiei Române. We found that although the kinetics of journal self-cites is generally faster compared to foreign cites, it shows some field-specific characteristics. Particularly in information science journals, the initial increase in a share of journal self-citations during post-publication year 0 was completely absent. Self-promoting journal self-citations of top-tier journals have rather indirect but negligible direct effects on bibliometric indicators, affecting just the immediacy index and marginally increasing the impact factor itself as long as the affected journals are well established in their fields. In contrast, other forms of journal self-citations and citation stacking may severely affect the impact factor, or other citation-based indices. We identified here a network consisting of three Romanian physics journals Proceedings of the Romanian Academy, Series A, Romanian Journal of Physics, and Romanian Reports in Physics, which displayed low to moderate ratio of journal self-citations, but which multiplied recently their impact factors, and were mutually responsible for 55.9%, 64.7% and 63.3% of citations within the impact factor calculation window to the three journals, respectively. They did not receive nearly any network self-cites prior impact factor calculation window, and their network self-cites decreased sharply after the impact factor calculation window. Journal self-citations and citation stacking requires increased attention and elimination from citation indices.
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Affiliation(s)
- Petr Heneberg
- Third Faculty of Medicine, Charles University in Prague, Praha, Czech Republic
- * E-mail:
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Mrízová I, Moserová M, Milichovský J, Šulc M, Kizek R, Kubáčková K, Arlt VM, Stiborová M. Heterologous expression of human cytochrome P450 2S1 in Escherichia coli and investigation of its role in metabolism of benzo[ a]pyrene and ellipticine. Monatsh Chem 2016; 147:881-888. [PMID: 27110039 PMCID: PMC4828499 DOI: 10.1007/s00706-016-1738-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 01/21/2016] [Indexed: 12/30/2022]
Abstract
ABSTRACT Cytochrome P450 (CYP) 2S1 is "orphan" CYP that is overexpressed in several epithelial tissues and many human tumors. The pure enzyme is required for better understanding of its biological functions. Therefore, human CYP2S1 was considered to be prepared by the gene manipulations and heterologous expression in Escherichia coli. Here, the conditions suitable for efficient expression of human CYP2S1 protein from plasmid pCW containing the human CYP2S1 gene were optimized and the enzyme purified to homogeneity. The identity of CYP2S1 as the product of heterologous expression was confirmed by dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and mass spectrometry. To confirm the presence of the enzymatically active CYP2S1, the CO spectrum of purified CYP2S1 was recorded. Since CYP2S1 was shown to catalyze oxidation of compounds having polycyclic aromatic structures, the prepared enzyme has been tested to metabolize the compounds having this structural character; namely, the human carcinogen benzo[a]pyrene (BaP), its 7,8-dihydrodiol derivative, and an anticancer drug ellipticine. Reaction mixtures contained besides the test compounds the CYP2S1 enzyme reconstituted with NADPH:CYP reductase (POR) in liposomes, and/or this CYP in the presence of cumene hydroperoxide or hydrogen peroxide. High performance liquid chromatography was employed for separation of BaP, BaP-7,8-dihydrodiol, and ellipticine metabolites. The results found in this study demonstrate that CYP2S1 in the presence of cumene hydroperoxide or hydrogen peroxide catalyzes oxidation of two of the test xenobiotics, a metabolite of BaP, BaP-7,8-dihydrodiol, and ellipticine. Whereas BaP-7,8,9,10-tetrahydrotetrol was formed as a product of BaP-7,8-dihydrodiol oxidation, ellipticine was oxidized to 12-hydroxyellipticine, 13-hydroxyellipticine, and the ellipticine N2-oxide. GRAPHICAL ABSTRACT
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Affiliation(s)
- Iveta Mrízová
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Michaela Moserová
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Jan Milichovský
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - Miroslav Šulc
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
| | - René Kizek
- />Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, 613 00 Brno, Czech Republic
| | - Kateřina Kubáčková
- />Department of Oncology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, V Uvalu 84, 150 06 Prague 5, Czech Republic
| | - Volker M. Arlt
- />Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King’s College London, London, SE1 9NH UK
| | - Marie Stiborová
- />Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40 Prague 2, Czech Republic
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