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Szabo E, Nagy B, Czajlik A, Komlodi T, Ozohanics O, Tretter L, Ambrus A. Mitochondrial Alpha-Keto Acid Dehydrogenase Complexes: Recent Developments on Structure and Function in Health and Disease. Subcell Biochem 2024; 104:295-381. [PMID: 38963492 DOI: 10.1007/978-3-031-58843-3_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The present work delves into the enigmatic world of mitochondrial alpha-keto acid dehydrogenase complexes discussing their metabolic significance, enzymatic operation, moonlighting activities, and pathological relevance with links to underlying structural features. This ubiquitous family of related but diverse multienzyme complexes is involved in carbohydrate metabolism (pyruvate dehydrogenase complex), the citric acid cycle (α-ketoglutarate dehydrogenase complex), and amino acid catabolism (branched-chain α-keto acid dehydrogenase complex, α-ketoadipate dehydrogenase complex); the complexes all function at strategic points and also participate in regulation in these metabolic pathways. These systems are among the largest multienzyme complexes with at times more than 100 protein chains and weights ranging up to ~10 million Daltons. Our chapter offers a wealth of up-to-date information on these multienzyme complexes for a comprehensive understanding of their significance in health and disease.
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Bernáth G, Csorbai B, Nagy B, Csókás E, Molnár J, Bartucz T, Láng ZL, Gyurcsák M, Hegyi Á, Kobolák J, Griffitts JD, Ferincz Á, Urbányi B, Bokor Z. The investigation of post-thaw chilled storage and the applicability of large-scale cryopreservation in chub (Squalius cephalus) sperm. Cryobiology 2023; 113:104588. [PMID: 37813176 DOI: 10.1016/j.cryobiol.2023.104588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 09/25/2023] [Accepted: 09/25/2023] [Indexed: 10/11/2023]
Abstract
Chub (reophillic cyprinids) is one of the most sensitive bioindicator fish of environmental changes following anthropogenic activities. The improvement of different biotechnological procedures could help support its conservation and strengthen the natural populations. The aim of this study was to compare the effects of two different hormonal agents (carp pituitary extract and Ovopel™) on various motility parameters (pMOT-%, DAP-μm, VCL μm s-1, VSL-μm s-1, LIN-%, ALH-μm, BCF-Hz) of fresh and cryopreserved/thawed sperm (stored at 4 °C for 6 h). Additionally, we sought to develop a novel, large-scale cryopreservation method for chub sperm, assessing freezing methods (Styrofoam box and a controlled-rate freezer) and different containers (0.5, 5 mL straw and 4 mL cryotube) for sperm cryopreservation. The results of this study indicated no difference between the carp pituitary extract and Ovopel treated groups in either the fresh or frozen/thawed sperm (at 0, 3, 6, hour post thawing, P = 0.4351). In contrast, the quality of the thawed chub sperm was negatively affected after 3 h chilled storage in both hormonal treatments (P = 0.0036, P < 0.0001). When assessing the motility parameters of the sperm between the 5 mL straw and 4 mL cryotube groups cryopreserved in a Styrofoam Box, no difference was observed (P = 0.103). Additionally, sperm loaded in 4 mL cryotubes showed no difference in motility when cryopreserved with either the Styrofoam box or controlled-rate freezer methods (P = 0.109). A similar hatching rate was observed in sperm preserved using the Styrofoam box (35 ± 7 %) and controlled rate freezer (25 ± 9 %) methods (P = 0.300). In a second fertilization trial, hatching rate was similar between control (72 ± 19 %) and cryopreserved (4 mL cryotube and Styrofoam box, 61 ± 5 %) groups. (P = 0.257). Based on our findings and its standard features (less species specific, precise dose calculation), Ovopel can be a good candidate for the stimulation of spermiation in chub sperm prior to cryopreservation. Furthermore, our study presents a novel and applicable method for the large-scale cryopreservation of chub sperm.
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Molnar F, Rendeki M, Rendeki S, Nagy B, Bacher V, Bogar P, Schlegl A, Koltai A, Maroti P, Marovics G. Validation of 3D printed MAYO tubes and stethoscope in simulated medical environment - Tools fabricated with additive manufacturing for emergency care. Heliyon 2023; 9:e20866. [PMID: 37916113 PMCID: PMC10616327 DOI: 10.1016/j.heliyon.2023.e20866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 09/29/2023] [Accepted: 10/09/2023] [Indexed: 11/03/2023] Open
Abstract
Emergency and disaster medical care often face resource or equipment shortages. 3D printing technology has been proven to be effective in cases with insufficient supply chains. MAYO tubes and stethoscopes are essential components of ABCDE patient examinations; however, 3D-printed variants have not been fully tested. These 3D-printed instruments were substituted and validated in a simulated pre-hospital environment. In total, 26 participants were included in this study. Fifteen clinicians or paramedics with at least 3 years of professional experience and 10 medical students. One student was excluded because he had relevant experience with emergency care. As basic tasks, the placement of MAYO tubes and auscultation with stethoscopes were performed using medical simulators. 3D printed instruments were compared with conventional clinical devices by measuring the time required for the intervention, success rate, and user satisfaction. In the study FFF (Fused Filament Fabrication (FFF), SLS (Selective Laser Sintering (SLS), and SLA (stereolithography) 3D printing were used in this study. The times required for implementation and auscultation were examined for each instrument. There was no significant difference between the MAYO tube (p = 0.798) and the stethoscope (p = 0.676). In the case of stethoscopy, the study investigated the correct diagnosis, and no significant difference was found (p = 0.239), although an interesting trend was observed. Regarding the MAYO tube, the study found no significant difference in correct position formation (p = 0.163). The experience levels of the groups did not influence these factors. However, significant differences in user satisfaction were found in both cases in favour of the conventional versions (p < 0.001). Overall, the results of this study suggest that 3D-printed devices could be suitable replacements for clinic-based devices in emergency situations. The 3D-printed devices did not perform inferiorly at any of the indicated points compared to their classical counterparts. However, the practical applicability of the devices used in this study requires further investigation.
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Szabo E, Nemes-Nikodem E, Vass KR, Zambo Z, Zrupko E, Torocsik B, Ozohanics O, Nagy B, Ambrus A. Structural and Biochemical Investigation of Selected Pathogenic Mutants of the Human Dihydrolipoamide Dehydrogenase. Int J Mol Sci 2023; 24:10826. [PMID: 37446004 PMCID: PMC10341545 DOI: 10.3390/ijms241310826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/16/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Clinically relevant disease-causing variants of the human dihydrolipoamide dehydrogenase (hLADH, hE3), a common component of the mitochondrial α-keto acid dehydrogenase complexes, were characterized using a multipronged approach to unravel the molecular pathomechanisms that underlie hLADH deficiency. The G101del and M326V substitutions both reduced the protein stability and triggered the disassembly of the functional/obligate hLADH homodimer and significant FAD losses, which altogether eventually manifested in a virtually undetectable catalytic activity in both cases. The I12T-hLADH variant proved also to be quite unstable, but managed to retain the dimeric enzyme form; the LADH activity, both in the forward and reverse catalytic directions and the affinity for the prosthetic group FAD were both significantly compromised. None of the above three variants lent themselves to an in-depth structural analysis via X-ray crystallography due to inherent protein instability. Crystal structures at 2.89 and 2.44 Å resolutions were determined for the I318T- and I358T-hLADH variants, respectively; structure analysis revealed minor conformational perturbations, which correlated well with the residual LADH activities, in both cases. For the dimer interface variants G426E-, I445M-, and R447G-hLADH, enzyme activities and FAD loss were determined and compared against the previously published structural data.
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Told R, Marada G, Rendeki S, Pentek A, Nagy B, Molnar FJ, Maroti P. Manufacturing a First Upper Molar Dental Forceps Using Continuous Fiber Reinforcement (CFR) Additive Manufacturing Technology with Carbon-Reinforced Polyamide. Polymers (Basel) 2021; 13:2647. [PMID: 34451187 PMCID: PMC8399141 DOI: 10.3390/polym13162647] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/01/2021] [Accepted: 08/04/2021] [Indexed: 12/23/2022] Open
Abstract
3D printing is an emerging and disruptive technology, supporting the field of medicine over the past decades. In the recent years, the use of additive manufacturing (AM) has had a strong impact on everyday dental applications. Despite remarkable previous results from interdisciplinary research teams, there is no evidence or recommendation about the proper fabrication of handheld medical devices using desktop 3D printers. The aim of this study was to critically examine and compare the mechanical behavior of materials printed with FFF (fused filament fabrication) and CFR (continuous fiber reinforcement) additive manufacturing technologies, and to create and evaluate a massive and practically usable right upper molar forceps. Flexural and torsion fatigue tests, as well as Shore D measurements, were performed. The tensile strength was also measured in the case of the composite material. The flexural tests revealed the measured force values to have a linear correlation with the bending between the 10 mm (17.06 N at 5000th cycle) and 30 mm (37.99 N at 5000th cycle) deflection range. The findings were supported by scanning electron microscopy (SEM) images. Based on the results of the mechanical and structural tests, a dental forceps was designed, 3D printed using CFR technology, and validated by five dentists using a Likert scale. In addition, the vertical force of extraction was measured using a unique molar tooth model, where the reference test was carried out using a standard metal right upper molar forceps. Surprisingly, the tests revealed there to be no significant differences between the standard (84.80 N ± 16.96 N) and 3D-printed devices (70.30 N ± 4.41 N) in terms of extraction force in the tested range. The results also highlighted that desktop CFR technology is potentially suitable for the production of handheld medical devices that have to withstand high forces and perform load-bearing functions.
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Nagy B, Polak M, Ozohanics O, Zambo Z, Szabo E, Hubert A, Jordan F, Novaček J, Adam-Vizi V, Ambrus A. Structure of the dihydrolipoamide succinyltransferase (E2) component of the human alpha-ketoglutarate dehydrogenase complex (hKGDHc) revealed by cryo-EM and cross-linking mass spectrometry: Implications for the overall hKGDHc structure. Biochim Biophys Acta Gen Subj 2021; 1865:129889. [PMID: 33684457 DOI: 10.1016/j.bbagen.2021.129889] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/05/2021] [Accepted: 03/02/2021] [Indexed: 12/19/2022]
Abstract
BACKGROUND The human mitochondrial alpha-ketoglutarate dehydrogenase complex (hKGDHc) converts KG to succinyl-CoA and NADH. Malfunction of and reactive oxygen species generation by the hKGDHc as well as its E1-E2 subcomplex are implicated in neurodegenerative disorders, ischemia-reperfusion injury, E3-deficiency and cancers. METHODS We performed cryo-EM, cross-linking mass spectrometry (CL-MS) and molecular modeling analyses to determine the structure of the E2 component of the hKGDHc (hE2k); hE2k transfers a succinyl group to CoA and forms the structural core of hKGDHc. We also assessed the overall structure of the hKGDHc by negative-stain EM and modeling. RESULTS We report the 2.9 Å resolution cryo-EM structure of the hE2k component. The cryo-EM map comprises density for hE2k residues 151-386 - the entire (inner) core catalytic domain plus a few additional residues -, while residues 1-150 are not observed due to the inherent flexibility of the N-terminal region. The structure of the latter segment was also determined by CL-MS and homology modeling. Negative-stain EM on in vitro assembled hKGDHc and previous data were used to build a putative overall structural model of the hKGDHc. CONCLUSIONS The E2 core of the hKGDHc is composed of 24 hE2k chains organized in octahedral (8 × 3 type) assembly. Each lipoyl domain is oriented towards the core domain of an adjacent chain in the hE2k homotrimer. hE1k and hE3 are most likely tethered at the edges and faces, respectively, of the cubic hE2k assembly. GENERAL SIGNIFICANCE The revealed structural information will support the future pharmacologically targeting of the hKGDHc.
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Tucker S, Fejes Z, Li QZ, Nagy B, Rada B. P131 The systemic IgA autoantibody profile of adult cystic fibrosis. J Cyst Fibros 2021. [DOI: 10.1016/s1569-1993(21)01157-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Rendeki S, Nagy B, Bene M, Pentek A, Toth L, Szanto Z, Told R, Maroti P. An Overview on Personal Protective Equipment (PPE) Fabricated with Additive Manufacturing Technologies in the Era of COVID-19 Pandemic. Polymers (Basel) 2020; 12:E2703. [PMID: 33207712 PMCID: PMC7697679 DOI: 10.3390/polym12112703] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 12/18/2022] Open
Abstract
Different additive manufacturing technologies have proven effective and useful in remote medicine and emergency or disaster situations. The coronavirus disease 2019 (COVID-19) disease, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus, has had a huge impact on our society, including in relation to the continuous supply of personal protective equipment (PPE). The aim of the study is to give a detailed overview of 3D-printed PPE devices and provide practical information regarding the manufacturing and further design process, as well as describing the potential risks of using them. Open-source models of a half-face mask, safety goggles, and a face-protecting shield are evaluated, considering production time, material usage, and cost. Estimations have been performed with fused filament fabrication (FFF) and selective laser sintering (SLS) technology, highlighting the material characteristics of polylactic acid (PLA), polyamide, and a two-compound silicone. Spectrophotometry measurements of transparent PMMA samples were performed to determine their functionality as goggles or face mask parts. All the tests were carried out before and after the tetra-acetyl-ethylene-diamine (TAED)-based disinfection process. The results show that the disinfection has no significant effect on the mechanical and structural stability of the used polymers; therefore, 3D-printed PPE is reusable. For each device, recommendations and possible means of development are explained. The files of the modified models are provided. SLS and FFF additive manufacturing technology can be useful tools in PPE development and small-series production, but open-source models must be used with special care.
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Zhang X, Nemeria NS, Leandro J, Houten S, Lazarus M, Gerfen G, Ozohanics O, Ambrus A, Nagy B, Brukh R, Jordan F. Structure-function analyses of the G729R 2-oxoadipate dehydrogenase genetic variant associated with a disorder of l-lysine metabolism. J Biol Chem 2020; 295:8078-8095. [PMID: 32303640 PMCID: PMC7278340 DOI: 10.1074/jbc.ra120.012761] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/16/2020] [Indexed: 12/13/2022] Open
Abstract
2-Oxoadipate dehydrogenase (E1a, also known as DHTKD1, dehydrogenase E1, and transketolase domain-containing protein 1) is a thiamin diphosphate-dependent enzyme and part of the 2-oxoadipate dehydrogenase complex (OADHc) in l-lysine catabolism. Genetic findings have linked mutations in the DHTKD1 gene to several metabolic disorders. These include α-aminoadipic and α-ketoadipic aciduria (AMOXAD), a rare disorder of l-lysine, l-hydroxylysine, and l-tryptophan catabolism, associated with clinical presentations such as developmental delay, mild-to-severe intellectual disability, ataxia, epilepsy, and behavioral disorders that cannot currently be managed by available treatments. A heterozygous missense mutation, c.2185G→A (p.G729R), in DHTKD1 has been identified in most AMOXAD cases. Here, we report that the G729R E1a variant when assembled into OADHc in vitro displays a 50-fold decrease in catalytic efficiency for NADH production and a significantly reduced rate of glutaryl-CoA production by dihydrolipoamide succinyl-transferase (E2o). However, the G729R E1a substitution did not affect any of the three side-reactions associated solely with G729R E1a, prompting us to determine the structure-function effects of this mutation. A multipronged systematic analysis of the reaction rates in the OADHc pathway, supplemented with results from chemical cross-linking and hydrogen-deuterium exchange MS, revealed that the c.2185G→A DHTKD1 mutation affects E1a-E2o assembly, leading to impaired channeling of OADHc intermediates. Cross-linking between the C-terminal region of both E1a and G729R E1a with the E2o lipoyl and core domains suggested that correct positioning of the C-terminal E1a region is essential for the intermediate channeling. These findings may inform the development of interventions to counter the effects of pathogenic DHTKD1 mutations.
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Szabo E, Wilk P, Nagy B, Zambo Z, Bui D, Weichsel A, Arjunan P, Torocsik B, Hubert A, Furey W, Montfort WR, Jordan F, Weiss MS, Adam-Vizi V, Ambrus A. Underlying molecular alterations in human dihydrolipoamide dehydrogenase deficiency revealed by structural analyses of disease-causing enzyme variants. Hum Mol Genet 2020; 28:3339-3354. [PMID: 31334547 DOI: 10.1093/hmg/ddz177] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 12/13/2022] Open
Abstract
Human dihydrolipoamide dehydrogenase (hLADH, hE3) deficiency (OMIM# 246900) is an often prematurely lethal genetic disease usually caused by inactive or partially inactive hE3 variants. Here we report the crystal structure of wild-type hE3 at an unprecedented high resolution of 1.75 Å and the structures of six disease-causing hE3 variants at resolutions ranging from 1.44 to 2.34 Å. P453L proved to be the most deleterious substitution in structure as aberrations extensively compromised the active site. The most prevalent G194C-hE3 variant primarily exhibited structural alterations close to the substitution site, whereas the nearby cofactor-binding residues were left unperturbed. The G426E substitution mainly interfered with the local charge distribution introducing dynamics to the substitution site in the dimer interface; G194C and G426E both led to minor structural changes. The R460G, R447G and I445M substitutions all perturbed a solvent accessible channel, the so-called H+/H2O channel, leading to the active site. Molecular pathomechanisms of enhanced reactive oxygen species (ROS) generation and impaired binding to multienzyme complexes were also addressed according to the structural data for the relevant mutations. In summary, we present here for the first time a comprehensive study that links three-dimensional structures of disease-causing hE3 variants to residual hLADH activities, altered capacities for ROS generation, compromised affinities for multienzyme complexes and eventually clinical symptoms. Our results may serve as useful starting points for future therapeutic intervention approaches.
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Budis J, Gazdarica J, Radvanszky J, Szucs G, Kucharik M, Strieskova L, Gazdaricova I, Harsanyova M, Duris F, Minarik G, Sekelska M, Nagy B, Turna J, Szemes T. Combining count- and length-based z-scores leads to improved predictions in non-invasive prenatal testing. Bioinformatics 2020; 35:1284-1291. [PMID: 30219853 DOI: 10.1093/bioinformatics/bty806] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/16/2018] [Accepted: 09/13/2018] [Indexed: 02/06/2023] Open
Abstract
MOTIVATION Non-invasive prenatal testing or NIPT is currently among the top researched topic in obstetric care. While the performance of the current state-of-the-art NIPT solutions achieve high sensitivity and specificity, they still struggle with a considerable number of samples that cannot be concluded with certainty. Such uninformative results are often subject to repeated blood sampling and re-analysis, usually after two weeks, and this period may cause a stress to the future mothers as well as increase the overall cost of the test. RESULTS We propose a supplementary method to traditional z-scores to reduce the number of such uninformative calls. The method is based on a novel analysis of the length profile of circulating cell free DNA which compares the change in such profiles when random-based and length-based elimination of some fragments is performed. The proposed method is not as accurate as the standard z-score; however, our results suggest that combination of these two independent methods correctly resolves a substantial portion of healthy samples with an uninformative result. Additionally, we discuss how the proposed method can be used to identify maternal aberrations, thus reducing the risk of false positive and false negative calls. AVAILABILITY AND IMPLEMENTATION The open-source code of the proposed methods, together with test data, is freely available for non-commercial users at github web page https://github.com/jbudis/lambda. SUPPLEMENTARY INFORMATION Supplementary materials are available at Bioinformatics online.
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Voko Z, Molnar A, Valay V, Moizs M, Kerpel-Fronius A, Bajzik G, Horvath I, Nagy B. Cost-effectiveness analysis of low-dose computed tomography screening for lung cancer in Hungary. Eur J Public Health 2019. [DOI: 10.1093/eurpub/ckz186.293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Hungary has the highest incidence of lung cancer in the world (GLOBOCAN, 2018). Since lung cancer is rarely treatable in its advanced stage, one possible way to reduce mortality is early diagnosis and subsequent treatment. The possibility and necessity of introducing low-dose computed tomography (LDCT) lung cancer screening as a public health programme is a current and relevant health policy issue.
Methods
A Markov cohort model was built to assess the cost-effectiveness of such a risk group screening programme in Hungary. The model was populated with transition probabilities and resource utilization data derived from the HUNCHEST Hungarian lung cancer screening trial. The model results are presented in incremental cost-effectiveness ratio.
Results
A closed cohort of 10,000 smokers with the average starting age of 59 years was followed over life-time horizon and screened for lung cancer annually until the age of 74. Compared to the current scenario of no organized lung cancer screening in Hungary, the model resulted in an additional 0.1614 life-year gained per individual and an additional 0.2924 disease-free life-year gained per individual with annual screening frequency. The incremental cost-effectiveness ratio was EUR 608 indicating that assessed intervention is cost-effective in the analyzed setting. Sensitivity analyses confirmed the robustness of the model results.
Conclusions
Results suggest that introducing low-dose computed tomography screening for lung cancer is a cost-effective intervention in Hungary. Considering the exceptionally high incidence and mortality of lung cancer in Hungary, the population could benefit from such a risk group screening programme.
Key messages
Low-dose computed tomography screening for lung cancer is cost-effectiveness in the Hungarian setting. Policy makers are encouraged to consider the introduction of a risk group screening programme.
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Nagy B. 20th anniversary - Department of Human Genetics, Faculty of Medicine, University of Debrecen - Current states and prospects of human genetics in Central-Eastern Europe. J Biotechnol 2019; 301:1. [PMID: 31181239 DOI: 10.1016/j.jbiotec.2019.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Simon-Stoeger L, Varga C, Greczula E, Nagy B. A journey into recycling of waste elastomers via a novel type of compatibilizing additives. EXPRESS POLYM LETT 2019. [DOI: 10.3144/expresspolymlett.2019.37] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Varga A, Bakacs M, Zentai A, Nagy B, Nagy-Lőrincz Z, Erdei G, Illés É, Varga-Nagy V, Sarkadi Nagy E, Cserháti Z, Kaposvári C. Assessment of the public catering act in primary schools in Hungary. Eur J Public Health 2018. [DOI: 10.1093/eurpub/cky212.681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Démuth B, Galata DL, Balogh A, Szabó E, Nagy B, Farkas A, Hirsch E, Pataki H, Vigh T, Mensch J, Verreck G, Nagy ZK, Marosi G. Application of hydroxypropyl methylcellulose as a protective agent against magnesium stearate induced crystallization of amorphous itraconazole. Eur J Pharm Sci 2018; 121:301-308. [PMID: 29902510 DOI: 10.1016/j.ejps.2018.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 04/16/2018] [Accepted: 06/11/2018] [Indexed: 12/27/2022]
Abstract
Itraconazole is a fungicide drug which has low bioavailability due to its poor water solubility. Amorphous solid dispersion (ASD) is a tool that has the potential to greatly increase the dissolution rate and extent of compounds. In this work, the dissolution of tablets containing the ASD of itraconazole with either hydroxypropyl methylcellulose (HPMC) or vinylpyrrolidone-vinyl acetate copolymer (PVPVA) was compared in order to find a formulation which can prevent the drug from the precipitation caused by magnesium stearate. Formulations containing the PVPVA-based ASD with HPMC included in various forms could reach 90% dissolution in 2 h, while HPMC-based ASDs could release 100% of the drug. However, HPMC-based ASD had remarkably poor grindability and low bulk density, which limited its processability and applicability. The latter issue could be resolved by roller compacting the ASD, which significantly increases the bulk density and the flowability of the powder blends used for tableting. This roller compaction step might be a base for the industrial application of HPMC-based, electrospun ASDs.
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Nagy B, Bene Z, Fejes Z, Heltshe S, Ronan N, Joseloff E, Kappelmayer J, Macek M, Bell S, Plant B, Amaral M, Balogh I. WS16.6 Human epididymis protein 4 (HE4) plasma levels inversely correlate with improved FEV1 in cystic fibrosis patients under ivacaftor therapy as a new sensitive treatment efficacy biomarker. J Cyst Fibros 2018. [DOI: 10.1016/s1569-1993(18)30213-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Nagy B, Merkel DG, Jakab L, Füzi J, Veres T, Bottyán L. Note: 4-bounce neutron polarizer for reflectometry applications. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:056105. [PMID: 29864798 DOI: 10.1063/1.5019252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A neutron polarizer using four successive reflections on m = 2.5 supermirrors was built and installed at the GINA neutron reflectometer at the Budapest Neutron Centre. This simple setup exhibits 99.6% polarizing efficiency with 80% transmitted intensity of the selected polarization state. Due to the geometry, the higher harmonics in the incident beam are filtered out, while the optical axis of the beam remains intact for easy mounting and dismounting the device in an existing experimental setup.
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Szabo E, Demuth B, Nagy B, Molnar K, Farkas A, Szabo B, Balogh A, Hirsch E, Nagy B, Marosi G, Nagy ZK. Scaled-up preparation of drug-loaded electrospun polymer fibres and investigation of their continuous processing to tablet form. EXPRESS POLYM LETT 2018. [DOI: 10.3144/expresspolymlett.2018.37] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Szilberhorn L, K?rösi L, Vájer P, Nagy B, Voko Z. Cost-effectiveness of controlling diabetes in primary care. Eur J Public Health 2017. [DOI: 10.1093/eurpub/ckx186.076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Démuth B, Galata DL, Szabó E, Nagy B, Farkas A, Balogh A, Hirsch E, Pataki H, Rapi Z, Bezúr L, Vigh T, Verreck G, Szalay Z, Demeter Á, Marosi G, Nagy ZK. Investigation of Deteriorated Dissolution of Amorphous Itraconazole: Description of Incompatibility with Magnesium Stearate and Possible Solutions. Mol Pharm 2017; 14:3927-3934. [PMID: 28972782 DOI: 10.1021/acs.molpharmaceut.7b00629] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Disadvantageous crystallization phenomenon of amorphous itraconazole (ITR) occurring in the course of dissolution process was investigated in this work. A perfectly amorphous form (solid dispersion) of the drug was generated by the electroblowing method (with vinylpyrrolidone-vinyl acetate copolymer), and the obtained fibers were formulated into tablets. Incomplete dissolution of the tablets was noticed under the circumstances of the standard dissolution test, after which a precipitated material could be filtered. The filtrate consisted of ITR and stearic acid since no magnesium content was detectable in it. In parallel with dissolution, ITR forms an insoluble associate, stabilized by hydrogen bonding, with stearic acid deriving from magnesium stearate. This is why dissolution curves do not have the plateaus at 100%. Two ways are viable to tackle this issue: change the lubricant (with sodium stearyl fumarate >95% dissolution can be accomplished) or alter the polymer in the solid dispersion to a type being able to form hydrogen bonds with ITR (e.g., hydroxypropyl methylcellulose). This work draws attention to one possible phenomenon that can lead to a deterioration of originally good dissolution of an amorphous solid dispersion.
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Nagy B, Hovhannisyan A, Barzan R, Chen TJ, Kukley M. Different patterns of neuronal activity trigger distinct responses of oligodendrocyte precursor cells in the corpus callosum. PLoS Biol 2017; 15:e2001993. [PMID: 28829781 PMCID: PMC5567905 DOI: 10.1371/journal.pbio.2001993] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 07/18/2017] [Indexed: 12/28/2022] Open
Abstract
In the developing and adult brain, oligodendrocyte precursor cells (OPCs) are influenced by neuronal activity: they are involved in synaptic signaling with neurons, and their proliferation and differentiation into myelinating glia can be altered by transient changes in neuronal firing. An important question that has been unanswered is whether OPCs can discriminate different patterns of neuronal activity and respond to them in a distinct way. Here, we demonstrate in brain slices that the pattern of neuronal activity determines the functional changes triggered at synapses between axons and OPCs. Furthermore, we show that stimulation of the corpus callosum at different frequencies in vivo affects proliferation and differentiation of OPCs in a dissimilar way. Our findings suggest that neurons do not influence OPCs in “all-or-none” fashion but use their firing pattern to tune the response and behavior of these nonneuronal cells. Oligodendrocytes are glial cells of the central nervous system. One of their major tasks is to enwrap neuronal axons with myelin, providing electrical insulation of axons and a dramatic increase in the speed of nerve impulse propagation. Oligodendrocytes develop from oligodendrocyte precursor cells (OPCs). Self-renewal of OPCs, their differentiation into oligodendrocytes, and the process of myelin synthesis are influenced by neuronal activity. Furthermore, OPCs receive glutamatergic synaptic input from neurons. Neuronal activity in vivo is highly variable depending on the brain region, input stimulus, and/or behavioral task that an animal or human has to perform in everyday life. Therefore, it is important to understand whether different types of neuronal activity affect development and function of oligodendrocyte lineage cells in a distinct way. In this study, we demonstrate that the amount and the timing of glutamate release at synapses between neurons and OPCs, the properties of the subsequent ionic current through glutamate receptors in OPC membrane, as well as the extent of OPCs’ self-renewal and differentiation into oligodendrocytes differ depending on the frequency and duration of neuronal activity. Hence, the pattern of neuronal activity rather than just presence or absence of activity is an important parameter that determines development and function of oligodendroglial cells.
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Csetényi B, Hormay E, Szabó I, Takács G, Nagy B, László K, Karádi Z. Food and water intake, body temperature and metabolic consequences of interleukin-1β microinjection into the cingulate cortex of the rat. Behav Brain Res 2017; 331:115-122. [PMID: 28527691 DOI: 10.1016/j.bbr.2017.05.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/04/2017] [Accepted: 05/16/2017] [Indexed: 12/30/2022]
Abstract
In order to elucidate whether cytokine mechanisms of the cingulate cortex (cctx) are important in the central regulation of homeostasis, in the present study, feeding-metabolic effects of direct bilateral microinjection of interleukin-1β (IL-1β) into the cctx of the rat have been investigated. Short- (2h), medium (12h) and long-term (24h) food and water intakes and body temperature were measured after the intracerebral administration of this primary cytokine or vehicle solution, with or without paracetamol pretreatment. The effect of IL-1β on the blood glucose level of animals was examined in glucose tolerance test (GTT), and concentrations of relevant plasma metabolites (total cholesterol, HDL, LDH, triglycerides, uric acid) were additionally also determined following the above microinjections. In contrast to causing no major alteration in the food and water intakes, the cytokine treatment evoked significant increase in the body temperature of the rats. Prostaglandin-mediated mechanisms were shown to have important role in the mode of this action of IL-1β, since paracetamol pretreatment partially prevented the development of the above mentioned hyperthermia. In the GTT, no considerable difference was observed between the blood glucose levels of the cytokine treated and control animals. Following IL-1β microinjection, however, significant decrease of HDL and total cholesterol was found. Our present findings indicate that elucidating the IL-1β mediated homeostatic control mechanisms in the cingulate cortex may lead to the better understanding not only the regulatory entities of the healthy organism but also those found in obesity, diabetes mellitus and other worldwide rapidly spreading feeding-metabolic disorders.
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Csongrádi É, Káplár M, Nagy B, Koch CA, Juhász A, Bajnok L, Varga Z, Seres I, Karányi Z, Magyar MT, Oláh L, Facskó A, Kappelmayer J, Paragh G. Adipokines as atherothrombotic risk factors in obese subjects: Associations with haemostatic markers and common carotid wall thickness. Nutr Metab Cardiovasc Dis 2017; 27:571-580. [PMID: 28428025 DOI: 10.1016/j.numecd.2017.02.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 02/21/2017] [Accepted: 02/25/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND AIMS Some crucial associations between obesity-related altered adipokine levels and the main factors of atherosclerotic, atherothrombotic processes are not fully known. We analysed the relationships of classic adipokines, namely leptin, resistin, adiponectin, tumour necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) with the markers of platelet activation, including mean platelet volume (MPV), platelet surface/soluble P-selectin, platelet-derived microparticles (PMPs), the parameters of coagulation abnormalities and common carotid intima-media thickness (IMT) in obese patients with or without atherosclerotic comorbidities in comparison to age- and sex-matched controls. METHODS AND RESULTS We enrolled 154 obese individuals, including 98 suffering from atherosclerotic concomitant conditions, 56 free of atherosclerotic comorbidities and 62 healthy controls. Plasma levels of leptin, resistin, adiponectin, TNF-α, IL-6, soluble P-selectin, and plasminogen activator inhibitor-1 antigen (PAI-1 ag) were analysed by ELISA. Platelet surface P-selectin and PMPs were measured by flow cytometry. IMT was detected by ultrasonography. Adipokines were closely associated with markers of platelet hyperactivity, hypercoagulability, hypofibrinolysis and IMT. Significant independent associations were found between leptin and platelet count (p < 0.0001), MPV (p = 0.019), PMPs (p < 0.0001), fibrinogen (p = 0.001), factor VIII (FVIII) activity (p = 0.035); adiponectin and PAI-1 ag (p = 0.035); resistin and soluble P-selectin (p = 0.002); TNF-α and PAI-1 ag (p < 0.0001); and IL-6 and fibrinogen (p = 0.011). Finally, leptin (p = 0.0005), adiponectin (p = 0.019), IL-6 (p = 0.001), MPV (p = 0.0003), PMP (p = 0.008), and FVIII activity (p = 0.043) were independent predictors of IMT. CONCLUSION Overall, we suggest that in obese subjects altered adipokine levels play a key role in common carotid atherosclerosis both directly and through haemostatic parameters.
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Démuth B, Farkas A, Szabó B, Balogh A, Nagy B, Vágó E, Vigh T, Tinke A, Kazsu Z, Demeter Á, Bertels J, Mensch J, Van Dijck A, Verreck G, Van Assche I, Marosi G, Nagy Z. Development and tableting of directly compressible powder from electrospun nanofibrous amorphous solid dispersion. ADV POWDER TECHNOL 2017. [DOI: 10.1016/j.apt.2017.03.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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