Implementation of mercury biomonitoring in German adults using dried blood spot sampling in combination with direct mercury analysis

Venous blood is a preferred matrix for the determination of total mercury (Hg) in human biomonitoring but has some drawbacks such as the requirement for an uninterrupted cold chain for transport and storage and the need of medical personnel for sample collection. Therefore, we tested and implemented a simpler and less expensive method for measuring Hg in human blood using dried blood spots (DBS). For method development, we investigated the influence of different storage conditions (temperature, storage vessel, time) on DBS samples. For method validation, we compared DBS and venous blood and investigated whether DBS sampling is suitable for measuring Hg in the general population in countries with low Hg exposure such as Germany. Based on our results, we found that pre-cleaned glass tubes were most suitable for storage of DBS samples, as this allowed the samples to remain stable for at least 4~weeks even at high temperatures (40~°C). When comparing venous blood and DBS, a very good correlation (r = 0.95, p < 0.01, Spearman-Rho) and high precision of DBS (mean relative standard deviation 8.2% vs. 7.2% in venous blood samples) were observed. Comparing the recoveries of both matrices in different concentration ranges, the variation of the recoveries decreases with increasing Hg concentration. The mean recoveries also decreased with increasing Hg concentration. Overall, we found comparable results for DBS and venous~blood using direct Hg analysis. Furthermore, we demonstrated that DBS are suitable for Hg biomonitoring in the general population in Germany and improved the storage conditions for the DBS

Homozygous mutation in TXNRD1 is associated with genetic generalized epilepsy

Increased oxidative stress has been widely implicated in the pathogenesis in various forms of human epilepsy. Here, we report a homozygous mutation in TXNRD1 (thioredoxin reductase 1) in a family with genetic generalized epilepsy. TXNRD1 is an essential selenium-containing enzyme involved in detoxification of reactive oxygen species (ROS) and redox signaling. The TXNRD1 mutation p.Pro190Leu affecting a highly conserved amino acid residue was identified by whole-exome sequencing of blood DNA from the index patient. The detected mutation and its segregation within the family- all siblings of the index patient were homozygous and the parents heterozygous-were confirmed by Sanger sequencing. TXNRD1 activity was determined in subcellular fractions from a skeletal muscle biopsy and skin fibroblasts of the index patient and the expression levels of the mutated protein were assessed by Se-75 labeling and Western blot analysis. As result of the mutation, the activity of TXNRD1 was reduced in the patient's fibroblasts and skeletal muscle (to 34 +/- 3% and 16 +/- 8% of controls, respectively). In fibroblasts, we detected reduced Se-75-labeling of the enzyme (41 +/- 3% of controls). An in-depth in vitro kinetic analysis of the recombinant mutated TXNRD1 indicated 30-40% lowered k(cat)/Se values. Therefore, a reduced activity of the enzyme in the patient's tissue samples is explained by (i) lower enzyme turnover and (ii) reduced abundance of the mutated enzyme as confirmed by Western blotting and Se-75 labeling. The mutant fibroblasts were also found to be less resistant to a hydrogen peroxide challenge. Our data agree with a potential role of insufficient ROS detoxification for disease manifestation in genetic generalized epilepsy

Global perspective of familial hypercholesterolaemia: a cross-sectional study from the EAS Familial Hypercholesterolaemia Studies Collaboration (FHSC)

none724siBackground The European Atherosclerosis Society Familial Hypercholesterolaemia Studies Collaboration (FHSC) global registry provides a platform for the global surveillance of familial hypercholesterolaemia through harmonisation and pooling of multinational data. In this study, we aimed to characterise the adult population with heterozygous familial hypercholesterolaemia and described how it is detected and managed globally.Methods Using FHSC global registry data, we did a cross-sectional assessment of adults (aged 18 years or older) with a clinical or genetic diagnosis of probable or definite heterozygous familial hypercholesterolaemia at the time they were entered into the registries. Data were assessed overall and by WHO regions, sex, and index versus non-index cases.Findings Of the 61 612 individuals in the registry, 42 167 adults (21 999 [53.6%] women) from 56 countries were included in the study. Of these, 31 798 (75.4%) were diagnosed with the Dutch Lipid Clinic Network criteria, and 35 490 (84.2%) were from the WHO region of Europe. Median age of participants at entry in the registry was 46.2 years (IQR 34.3-58.0); median age at diagnosis of familial hypercholesterolaemia was 44.4 years (32.5-56.5), with 40.2% of participants younger than 40 years when diagnosed. Prevalence of cardiovascular risk factors increased progressively with age and varied by WHO region. Prevalence of coronary disease was 17.4% (2.1% for stroke and 5.2% for peripheral artery disease), increasing with concentrations of untreated LDL cholesterol, and was about two times lower in women than in men. Among patients receiving lipid-lowering medications, 16 803 (81.1%) were receiving statins and 3691 (21.2%) were on combination therapy, with greater use of more potent lipid-lowering medication in men than in women. Median LDL cholesterol was 5.43 mmol/L (IQR 4.32-6.72) among patients not taking lipid-lowering medications and 4.23 mmol/L (3.20-5.66) among those taking them. Among patients taking lipid-lowering medications, 2.7% had LDL cholesterol lower than 1.8 mmol/L; the use of combination therapy, particularly with three drugs and with proprotein convertase subtilisin-kexin type 9 inhibitors, was associated with a higher proportion and greater odds of having LDL cholesterol lower than 1.8 mmol/L. Compared with index cases, patients who were non-index cases were younger, with lower LDL cholesterol and lower prevalence of cardiovascular risk factors and cardiovascular diseases (all p&lt;0.001).Interpretation Familial hypercholesterolaemia is diagnosed late. Guideline-recommended LDL cholesterol concentrations are infrequently achieved with single-drug therapy. Cardiovascular risk factors and presence of coronary disease were lower among non-index cases, who were diagnosed earlier. Earlier detection and greater use of combination therapies are required to reduce the global burden of familial hypercholesterolaemia. Copyright (C) 2021 Elsevier Ltd. All rights reserved.mixedVallejo-Vaz, Antonio J.; Stevens, Christophe A.T.; Lyons, Alexander R.M.; Dharmayat, Kanika I.; Freiberger, Tomas; Hovingh, G. Kees; Mata, Pedro; Raal, Frederick J.; Santos, Raul D.; Soran, Handrean; Watts, Gerald F.; Abifadel, Marianne; Aguilar-Salinas, Carlos A.; Alhabib, Khalid F.; Alkhnifsawi, Mutaz; Almahmeed, Wael; Alnouri, Fahad; Alonso, Rodrigo; Al-Rasadi, Khalid; Al-Sarraf, Ahmad; Al-Sayed, Nasreen; Araujo, Francisco; Ashavaid, Tester F.; Banach, Maciej; Béliard, Sophie; Benn, Marianne; Binder, Christoph J.; Bogsrud, Martin P.; Bourbon, Mafalda; Chlebus, Krzysztof; Corral, Pablo; Davletov, Kairat; Descamps, Olivier S.; Durst, Ronen; Ezhov, Marat; Gaita, Dan; Genest, Jacques; Groselj, Urh; Harada-Shiba, Mariko; Holven, Kirsten B.; Kayikcioglu, Meral; Khovidhunkit, Weerapan; Lalic, Katarina; Latkovskis, Gustavs; Laufs, Ulrich; Liberopoulos, Evangelos; Lima-Martinez, Marcos M.; Lin, Jie; Maher, Vincent; Marais, A. David; März, Winfried; Mirrakhimov, Erkin; Miserez, André R.; Mitchenko, Olena; Nawawi, Hapizah; Nordestgaard, Børge G.; Panayiotou, Andrie G.; Paragh, György; Petrulioniene, Zaneta; Pojskic, Belma; Postadzhiyan, Arman; Raslova, Katarina; Reda, Ashraf; Reiner, Željko; Sadiq, Fouzia; Sadoh, Wilson Ehidiamen; Schunkert, Heribert; Shek, Aleksandr B.; Stoll, Mario; Stroes, Erik; Su, Ta-Chen; Subramaniam, Tavintharan; Susekov, Andrey V.; Tilney, Myra; Tomlinson, Brian; Truong, Thanh Huong; Tselepis, Alexandros D.; Tybjærg-Hansen, Anne; Vázquez Cárdenas, Alejandra; Viigimaa, Margus; Wang, Luya; Yamashita, Shizuya; Kastelein, John J.P.; Bruckert, Eric; Vohnout, Branislav; Schreier, Laura; Pang, Jing; Ebenbichler, Christoph; Dieplinger, Hans; Innerhofer, Reinhold; Winhofer-Stöckl, Yvonne; Greber-Platzer, Susanne; Krychtiuk, Konstantin; Speidl, Walter; Toplak, Hermann; Widhalm, Kurt; Stulnig, Thomas; Huber, Kurt; Höllerl, Florian; Rega-Kaun, Gersina; Kleemann, Lucas; Mäser, Martin; Scholl-Bürgi, Sabine; Säly, Christoph; Mayer, Florian J.; Sablon, Gaelle; Tarantino, Eric; Nzeyimana, Charlotte; Pojskic, Lamija; Sisic, Ibrahim; Nalbantic, Azra D.; Jannes, Cinthia E.; Pereira, Alexandre C.; Krieger, Jose E.; Petrov, Ivo; Goudev, Assen; Nikolov, Fedya; Tisheva, Snejana; Yotov, Yoto; Tzvetkov, Ivajlo; Baass, Alexis; Bergeron, Jean; Bernard, Sophie; Brisson, Diane; Brunham, Liam R.; Cermakova, Lubomira; Couture, Patrick; Francis, Gordon A.; Gaudet, Daniel; Hegele, Robert A.; Khoury, Etienne; Mancini, G.B. John; McCrindle, Brian W.; Paquette, Martine; Ruel, Isabelle; Cuevas, Ada; Asenjo, Sylvia; Wang, Xumin; Meng, Kang; Song, Xiantao; Yong, Qiang; Jiang, Tao; Liu, Ziyou; Duan, Yanyu; Hong, Jing; Ye, Pucong; Chen, Yan; Qi, Jianguang; Liu, Zesen; Li, Yuntao; Zhang, Chaoyi; Peng, Jie; Yang, Ya; Yu, Wei; Wang, Qian; Yuan, Hui; Cheng, Shitong; Jiang, Long; Chong, Mei; Jiao, Jian; Wu, Yue; Wen, Wenhui; Xu, Liyuan; Zhang, Ruiying; Qu, Yichen; He, Jianxun; Fan, Xuesong; Wang, Zhenjia; Chow, Elaine; Pećin, Ivan; Perica, Dražen; Symeonides, Phivos; Vrablik, Michal; Ceska, Richard; Soska, Vladimir; Tichy, Lukas; Adamkova, Vera; Franekova, Jana; Cifkova, Renata; Kraml, Pavel; Vonaskova, Katerina; Cepova, Jana; Dusejovska, Magdalena; Pavlickova, Lenka; Blaha, Vladimir; Rosolova, Hana; Nussbaumerova, Barbora; Cibulka, Roman; Vaverkova, Helena; Cibickova, Lubica; Krejsova, Zdenka; Rehouskova, Katerina; Malina, Pavel; Budikova, Milena; Palanova, Vaclava; Solcova, Lucie; Lubasova, Alena; Podzimkova, Helena; Bujdak, Juraj; Vesely, Jiri; Jordanova, Marta; Salek, Tomas; Urbanek, Robin; Zemek, Stanislav; Lacko, Jan; Halamkova, Hana; Machacova, Sona; Mala, Sarka; Cubova, Eva; Valoskova, Katerina; Burda, Lukas; Bendary, Ahmed; Daoud, Ihab; Emil, Sameh; Elbahry, Atef; Rafla, Samir; Sanad, Osama; Kazamel, Ghada; Ashraf, Mohamed; Sobhy, Mohamed; El-Hadidy, Amro; Shafy, Mohamed A.; Kamal, Saif; Bendary, Mohamed; Talviste, Grete; Angoulvant, Denis; Boccara, Franck; Cariou, Bertrand; Carreau, Valérie; Carrie, Alain; Charrieres, Sybil; Cottin, Yves; Di-Fillipo, Mathilde; Ducluzeau, Pierre H.; Dulong, Sonia; Durlach, Vincent; Farnier, Michel; Ferrari, Emile; Ferrieres, Dorota; Ferrieres, Jean; Gallo, Antonio; hankard, Regis; Inamo, Jocelyne; Lemale, Julie; Moulin, Philippe; Paillard, François; Peretti, Noel; Perrin, Agnès; Pradignac, Alain; Rabes, Jean P.; Rigalleau, Vincent; Sultan, Ariane; Schiele, François; Tounian, Patrick; Valero, René; Verges, Bruno; Yelnik, Cécile; Ziegler, Olivier; Haack, Ira A.; Schmidt, Nina; Dressel, Alexander; Klein, Isabel; Christmann, Jutta; Sonntag, Antonia; Stumpp, Christine; Boger, Diana; Biedermann, Dana; Usme, Monica M.N.; Beil, F. Ulrich; Klose, Gerald; König, Christel; Gouni-Berthold, Ioanna; Otte, Britta; Böll, Gereon; Kirschbaum, Anja; Merke, Jürgen; Scholl, Johannes; Segiet, Thomas; Gebauer, Marco; Predica, Florentina; Mayer, Manfred; Leistikow, Frank; Füllgraf-Horst, Sabine; Müller, Cornelius; Schüler, Melanie; Wiener, Judith; Hein, Konrad; Baumgartner, Peter; Kopf, Stefan; Busch, Reinhold; Schömig, Michael; Matthias, Stephan; Allendorf-Ostwald, Nicole; Fink, Bruno; Böhm, Dieter; Jäkel, Alexander; Koschker, Ann-Cathrin; Schweizer, Rüdiger; Vogt, Anja; Parhofer, Klaus; König, Wolfgang; Reinhard, Wibke; Bäßler, Andrea; Stadelmann, Alexander; Schrader, Volker; Katzmann, Julius; Tarr, Adrienne; Steinhagen-Thiessen, Elisabeth; Kassner, Ursula; Paulsen, Gerret; Homberger, Jürgen; Zemmrich, Claudia; Seeger, Wolfgang; Biolik, Kathrin; Deiss, Dorothee; Richter, Corinna; Pantchechnikova, Elina; Dorn, Elena; Schatz, Ulrike; Julius, Ulrich; Spens, Antje; Wiesner, Tobias; Scholl, Michael; Rizos, Christos V.; Sakkas, Nikolaos; Elisaf, Moses; Skoumas, Ioannis; Tziomalos, Konstantinos; Rallidis, Loukianos; Kotsis, Vasileios; Doumas, Michalis; Athyros, Vasileios; Skalidis, Emmanouil; Kolovou, Genovefa; Garoufi, Anastasia; Bilianou, Eleni; Koutagiar, Iosif; Agapakis, Dimitrios; Kiouri, Estela; Antza, Christina; Katsiki, Niki; Zacharis, Evangelos; Attilakos, Achilleas; Sfikas, George; Koumaras, Charalambos; Anagnostis, Panagiotis; Anastasiou, Georgia; Liamis, George; Koutsogianni, Amalia-Despoina; Karányi, Zsolt; Harangi, Mariann; Bajnok, László; Audikovszky, Mária; Márk, László; Benczúr, Béla; Reiber, István; Nagy, Gergely; Nagy, András; Reddy, Lakshmi L.; Shah, Swarup A.V.; Ponde, Chandrashekhar K.; Dalal, Jamshed J.; Sawhney, Jitendra P.S.; Verma, Ishwar C.; Altaey, Mays; Al-Jumaily, Khalid; Rasul, Dilshad; Abdalsahib, Ali F.; Jabbar, Amer A.; Al-ageedi, Mohanad; Agar, Ruth; Cohen, Hofit; Ellis, Avishay; Gavishv, Dov; Harats, Dror; Henkin, Yaacov; Knobler, Hila; Leavit, Leah; Leitersdorf, Eran; Rubinstein, Ardon; Schurr, Daniel; Shpitzen, Shoshi; Szalat, Auryan; Casula, Manuela; Zampoleri, Veronica; Gazzotti, Marta; Olmastroni, Elena; Sarzani, Riccardo; Ferri, Claudio; Repetti, Elena; Sabbà, Carlo; Bossi, Antonio Carlo; Borghi, Claudio; Muntoni, Sandro; Cipollone, Francesco; Purrello, Francesco; Pujia, Arturo; Passaro, Angelina; Marcucci, Rossella; Pecchioli, Valerio; Pisciotta, Livia; Mandraffino, Giuseppe; Pellegatta, Fabio; Mombelli, Giuliana; Branchi, Adriana; Fiorenza, Anna Maria; Pederiva, Cristina; Werba, Josè Pablo; Parati, Gianfranco; Carubbi, Francesca; Iughetti, Lorenzo; Iannuzzi, Arcangelo; Iannuzzo, Gabriella; Calabrò, Paolo; Averna, Maurizio; Biasucci, Giacomo; Zambon, Sabina; Roscini, Anna Rita; Trenti, Chiara; Arca, Marcello; Federici, Massimo; Del Ben, Maria; Bartuli, Andrea; Giaccari, Andrea; Pipolo, Antonio; Citroni, Nadia; Guardamagna, Ornella; Bonomo, Katia; Benso, Andrea; Biolo, Gianni; Maroni, Lorenzo; Lupi, Alessandro; Bonanni, Luca; Zenti, Maria Grazia; Matsuki, Kota; Hori, Mika; Ogura, Masatsune; Masuda, Daisaku; Kobayashi, Takuya; Nagahama, Kumiko; Al-Jarallah, Mohammed; Radovic, Mirjana; Lunegova, Olga; Bektasheva, Erkayim; Khodzhiboboev, Elyor; Erglis, Andrejs; Gilis, Dainus; Nesterovics, Georgijs; Saripo, Vita; Meiere, Ruta; Upena-RozeMicena, Arta; Terauda, Elizabete; Jambart, Selim; Khoury, Petra E.; Elbitar, Sandy; Ayoub, Carine; Ghaleb, Youmna; Aliosaitiene, Urte; Kutkiene, Sandra; Kasim, Noor A.M.; Nor, Noor S.M.; Ramli, Anis S.; Razak, Suraya A.; Al-Khateeb, Alyaa; Kadir, Siti H.S.A.; Muid, Suhaila A.; Rahman, Thuhairah A.; Kasim, Sazzli S.; Radzi, Ahmad B.M.; Ibrahim, Khairul S.; Razali, Salmi; Ismail, Zaliha; Ghani, Rohana A.; Hafidz, Muhammad I.A.; Chua, Ang L.; Rosli, Marshima M.; Annamalai, Muthukkaruppan; Teh, Lay K.; Razali, Rafezah; Chua, Yung A.; Rosman, Azhari; Sanusi, Abdul R.; Murad, Nor A.A.; Jamal, A. Rahman A.; Nazli, Sukma A.; Razman, Aimi Z.; Rosman, Norhidayah; Rahmat, Radzi; Hamzan, Nur S.; Azzopardi, C.; Mehta, Roopa; Martagon, Alexandro J.; Ramirez, Gabriela A.G.; Villa, Neftali E.A.; Vazquez, Arsenio V.; Elias-Lopez, Daniel; Retana, Gustavo G.; Rodriguez, Betsabel; Macías, Jose J.C.; Zazueta, Alejandro R.; Alvarado, Rocio M.; Portano, Julieta D.M.; Lopez, Humberto A.; Sauque-Reyna, Leobardo; Herrera, Laura G.G.; Mendia, Luis E.S.; Aguilar, Humberto Garcia; Cooremans, Elizabeth R.; Aparicio, Berenice P.; Zubieta, Victoria M.; Gonzalez, Perla A.C.; Ferreira-Hermosillo, Aldo; Portilla, Nacu C.; Dominguez, Guadalupe J.; Garcia, Alinna Y.R.; Cazares, Hector E.A.; Gonzalez, Jesus R.; Valencia, Carla V.M.; Padilla, Francisco G.; Prado, Ramon M.; De los Rios Ibarra, Manuel O.; Villicaña, Ruy D.A.; Rivera, Karina J.A.; Carrera, Ricardo A.; Alvarez, Jose A.; Martinez, Jose C.A.; de los Reyes Barrera Bustillo, Manuel; Vargas, Gonzalo C.; Chacon, Roberto C.; Andrade, Mario H.F.; Ortega, Ashanty F.; Alcala, Hector G.; de Leon, Laura E.G.; Guzman, Berenice G.; Garcia, Jose J.G.; Cuellar, Juan C.G.; Cruz, Jose R.G.; Garcia, Anell Hernandez; Almada, Jesus R.H.; Herrera, Ursulo J.; Sobrevilla, Fabiola L.; Rodriguez, Eduardo M.; Sibaja, Cristina M.; Rodriguez, Alma B.M.; Oyervides, Jose C.M.; Vazquez, Daniel I.P.; Rodriguez, Eduardo A.R.; Osorio, Ma L.R.; Saucedo, Juan R.; Tamayo, Margarita T.; Talavera, Luis A.V.; Arroyo, Luis E.V.; Carrillo, Eloy A.Z.; Isara, Alphonsus; Obaseki, Darlington E.; Al-Waili, Khalid; Al-Zadjali, Fahad; Al-Zakwani, Ibrahim; Al-Kindi, Mohammed; Al-Mukhaini, Suad; Al-Barwani, Hamida; Rana, Asim; Shah, Lahore S.U.; Starostecka, Ewa; Konopka, Agnieszka; Lewek, Joanna; Bartłomiejczyk, Marcin; Gąsior, Mariusz; Dyrbuś, Krzysztof; Jóźwiak, Jacek; Gruchała, Marcin; Pajkowski, Marcin; Romanowska-Kocejko, Marzena; Żarczyńska-Buchowiecka, Marta; Chmara, Magdalena; Wasąg, Bartosz; Parczewska, Aleksandra; Gilis-Malinowska, Natasza; Borowiec-Wolna, Justyna; Stróżyk, Aneta; Woś, Marlena; Michalska-Grzonkowska, Aleksandra; Medeiros, Ana M.; Alves, Ana C.; Silva, Francisco; Lobarinhas, Goreti; Palma, Isabel; de Moura, Jose P.; Rico, Miguel T.; Rato, Quitéria; Pais, Patrícia; Correia, Susana; Moldovan, Oana; Virtuoso, Maria J.; Salgado, Jose M.; Colaço, Ines; Dumitrescu, Andreea; Lengher, Calin; Mosteoru, Svetlana; Meshkov, Alexey; Ershova, Alexandra; Rozkova, Tatiana; Korneva, Victoria; Yu, Kuznetsova T.; Zafiraki, Vitaliy; Voevoda, Mikhail; Gurevich, Victor; Duplyakov, Dmitry; Ragino, Yulia; Safarova, Maya; Shaposhnik, Igor; Alkaf, Fahmi; Khudari, Alia; Rwaili, Nawal; Al-Allaf, Faisal; Alghamdi, Mohammad; Batais, Mohammed A.; Almigbal, Turky H.; Kinsara, Abdulhalim; AlQudaimi, Ashraf H.A.; Awan, Zuhier; Elamin, Omer A.; Altaradi, Hani; Rajkovic, Natasa; Popovic, Ljiljana; Singh, Sandra; Stosic, Ljubica; Rasulic, Iva; Lalic, Nebojsa M.; Lam, Carolyn; Le, Tan J.; Siang, Eric L.T.; Dissanayake, Sanjaya; I-Shing, Justin T.; Shyong, Tai E.; Jin, Terrance C.S.; Balinth, Karin; Buganova, Ingrid; Fabryova, Lubomira; Kadurova, Michaela; Klabnik, Alexander; Kozárová, Miriam; Sirotiakova, Jana; Battelino, Tadej; Kovac, Jernej; Mlinaric, Matej; Sustar, Ursa; Podkrajsek, Katarina T.; Fras, Zlatko; Jug, Borut; Cevc, Matija; Pilcher, Gillian J.; Blom, D.J.; Wolmarans, K.H.; Brice, B.C.; Muñiz-Grijalvo, Ovidio; Díaz-Díaz, Jose L.; de Isla, Leopoldo P.; Fuentes, Francisco; Badimon, Lina; Martin, François; Lux, Angela; Chang, Nien-Tzu; Ganokroj, Poranee; Akbulut, Mehmet; Alici, Gökhan; Bayram, Fahri; Can, Levent H.; Celik, Ahmet; Ceyhan, Ceyhun; Coskun, Fatma Y.; Demir, Mesut; Demircan, Sabri; Dogan, Volkan; Durakoglugil, Emre; Dural, Ibrahim E.; Gedikli, Omer; Hacioglu, Aysa; Ildizli, Muge; Kilic, Salih; Kirilmaz, Bahadir; Kutlu, Merih; Oguz, Aytekin; Ozdogan, Oner; Onrat, Ersel; Ozer, Savas; Sabuncu, Tevfik; Sahin, Tayfun; Sivri, Fatih; Sonmez, Alper; Temizhan, Ahmet; Topcu, Selim; Tuncez, Abdullah; Vural, Mirac; Yenercag, Mustafa; Yesilbursa, Dilek; Yigit, Zerrin; Yildirim, Aytul B.; Yildirir, Aylin; Yilmaz, Mehmet B.; Atallah, Bassam; Traina, Mahmoud; Sabbour, Hani; Hay, Dana A.; Luqman, Neama; Elfatih, Abubaker; Abdulrasheed, Arshad; Kwok, See; Oca, Nicolas D.; Reyes, Ximena; Alieva, Rano B.; Kurbanov, Ravshanbek D.; Hoshimov, Shavkat U.; Nizamov, Ulugbek I.; Ziyaeva, Adolat V.; Abdullaeva, Guzal J.; Do, Doan L.; Nguyen, Mai N.T.; Kim, Ngoc T.; Le, Thanh T.; Le, Hong A.; Tokgozoglu, Lale; Catapano, Alberico L.; Ray, Kausik K.Vallejo-Vaz, Antonio J.; Stevens, Christophe A. T.; Lyons, Alexander R. M.; Dharmayat, Kanika I.; Freiberger, Tomas; Hovingh, G. Kees; Mata, Pedro; Raal, Frederick J.; Santos, Raul D.; Soran, Handrean; Watts, Gerald F.; Abifadel, Marianne; Aguilar-Salinas, Carlos A.; Alhabib, Khalid F.; Alkhnifsawi, Mutaz; Almahmeed, Wael; Alnouri, Fahad; Alonso, Rodrigo; Al-Rasadi, Khalid; Al-Sarraf, Ahmad; Al-Sayed, Nasreen; Araujo, Francisco; Ashavaid, Tester F.; Banach, Maciej; Béliard, Sophie; Benn, Marianne; Binder, Christoph J.; Bogsrud, Martin P.; Bourbon, Mafalda; Chlebus, Krzysztof; Corral, Pablo; Davletov, Kairat; Descamps, Olivier S.; Durst, Ronen; Ezhov, Marat; Gaita, Dan; Genest, Jacques; Groselj, Urh; Harada-Shiba, Mariko; Holven, Kirsten B.; Kayikcioglu, Meral; Khovidhunkit, Weerapan; Lalic, Katarina; Latkovskis, Gustavs; Laufs, Ulrich; Liberopoulos, Evangelos; Lima-Martinez, Marcos M.; Lin, Jie; Maher, Vincent; Marais, A. David; März, Winfried; Mirrakhimov, Erkin; Miserez, André R.; Mitchenko, Olena; Nawawi, Hapizah; Nordestgaard, Børge G.; Panayiotou, Andrie G.; Paragh, György; Petrulioniene, Zaneta; Pojskic, Belma; Postadzhiyan, Arman; Raslova, Katarina; Reda, Ashraf; Reiner, Željko; Sadiq, Fouzia; Sadoh, Wilson Ehidiamen; Schunkert, Heribert; Shek, Aleksandr B.; Stoll, Mario; Stroes, Erik; Su, Ta-Chen; Subramaniam, Tavintharan; Susekov, Andrey V.; Tilney, Myra; Tomlinson, Brian; Truong, Thanh Huong; Tselepis, Alexandros D.; Tybjærg-Hansen, Anne; Vázquez Cárdenas, Alejandra; Viigimaa, Margus; Wang, Luya; Yamashita, Shizuya; Kastelein, John J. P.; Bruckert, Eric; Vohnout, Branislav; Schreier, Laura; Pang, Jing; Ebenbichler, Christoph; Dieplinger, Hans; Innerhofer, Reinhold; Winhofer-Stöckl, Yvonne; Greber-Platzer, Susanne; Krychtiuk, Konstantin; Speidl, Walter; Toplak, Hermann; Widhalm, Kurt; Stulnig, Thomas; Huber, Kurt; Höllerl, Florian; Rega-Kaun, Gersina; Kleemann, Lucas; Mäser, Martin; Scholl-Bürgi, Sabine; Säly, Christoph; Mayer, Florian J.; Sablon, Gaelle; Tarantino, Eric; Nzeyimana, Charlotte; Pojskic, Lamija; Sisic, Ibrahim; Nalbantic, Azra D.; Jannes, Cinthia E.; Pereira, Alexandre C.; Krieger, Jose E.; Petrov, Ivo; Goudev, Assen; Nikolov, Fedya; Tisheva, Snejana; Yotov, Yoto; Tzvetkov, Ivajlo; Baass, Alexis; Bergeron, Jean; Bernard, Sophie; Brisson, Diane; Brunham, Liam R.; Cermakova, Lubomira; Couture, Patrick; Francis, Gordon A.; Gaudet, Daniel; Hegele, Robert A.; Khoury, Etienne; Mancini, G. B. John; Mccrindle, Brian W.; Paquette, Martine; Ruel, Isabelle; Cuevas, Ada; Asenjo, Sylvia; Wang, Xumin; Meng, Kang; Song, Xiantao; Yong, Qiang; Jiang, Tao; Liu, Ziyou; Duan, Yanyu; Hong, Jing; Ye, Pucong; Chen, Yan; Qi, Jianguang; Liu, Zesen; Li, Yuntao; Zhang, Chaoyi; Peng, Jie; Yang, Ya; Yu, Wei; Wang, Qian; Yuan, Hui; Cheng, Shitong; Jiang, Long; Chong, Mei; Jiao, Jian; Wu, Yue; Wen, Wenhui; Xu, Liyuan; Zhang, Ruiying; Qu, Yichen; He, Jianxun; Fan, Xuesong; Wang, Zhenjia; Chow, Elaine; Pećin, Ivan; Perica, Dražen; Symeonides, Phivos; Vrablik, Michal; Ceska, Richard; Soska, Vladimir; Tichy, Lukas; Adamkova, Vera; Franekova, Jana; Cifkova, Renata; Kraml, Pavel; Vonaskova, Katerina; Cepova, Jana; Dusejovska, Magdalena; Pavlickova, Lenka; Blaha, Vladimir; Rosolova, Hana; Nussbaumerova, Barbora; Cibulka, Roman; Vaverkova, Helena; Cibickova, Lubica; Krejsova, Zdenka; Rehouskova, Katerina; Malina, Pavel; Budikova, Milena; Palanova, Vaclava; Solcova, Lucie; Lubasova, Alena; Podzimkova, Helena; Bujdak, Juraj; Vesely, Jiri; Jordanova, Marta; Salek, Tomas; Urbanek, Robin; Zemek, Stanislav; Lacko, Jan; Halamkova, Hana; Machacova, Sona; Mala, Sarka; Cubova, Eva; Valoskova, Katerina; Burda, Lukas; Bendary, Ahmed; Daoud, Ihab; Emil, Sameh; Elbahry, Atef; Rafla, Samir; Sanad, Osama; Kazamel, Ghada; Ashraf, Mohamed; Sobhy, Mohamed; El-Hadidy, Amro; Shafy, Mohamed A.; Kamal, Saif; Bendary, Mohamed; Talviste, Grete; Angoulvant, Denis; Boccara, Franck; Cariou, Bertrand; Carreau, Valérie; Carrie, Alain; Charrieres, Sybil; Cottin, Yves; Di-Fillipo, Mathilde; Ducluzeau, Pierre H.; Dulong, Sonia; Durlach, Vincent; Farnier, Michel; Ferrari, Emile; Ferrieres, Dorota; Ferrieres, Jean; Gallo, Antonio; Hankard, Regis; Inamo, Jocelyne; Lemale, Julie; Moulin, Philippe; Paillard, François; Peretti, Noel; Perrin, Agnès; Pradignac, Alain; Rabes, Jean P.; Rigalleau, Vincent; Sultan, Ariane; Schiele, François; Tounian, Patrick; Valero, René; Verges, Bruno; Yelnik, Cécile; Ziegler, Olivier; Haack, Ira A.; Schmidt, Nina; Dressel, Alexander; Klein, Isabel; Christmann, Jutta; Sonntag, Antonia; Stumpp, Christine; Boger, Diana; Biedermann, Dana; Usme, Monica M. N.; Beil, F. Ulrich; Klose, Gerald; König, Christel; Gouni-Berthold, Ioanna; Otte, Britta; Böll, Gereon; Kirschbaum, Anja; Merke, Jürgen; Scholl, Johannes; Segiet, Thomas; Gebauer, Marco; Predica, Florentina; Mayer, Manfred; Leistikow, Frank; Füllgraf-Horst, Sabine; Müller, Cornelius; Schüler, Melanie; Wiener, Judith; Hein, Konrad; Baumgartner, Peter; Kopf, Stefan; Busch, Reinhold; Schömig, Michael; Matthias, Stephan; Allendorf-Ostwald, Nicole; Fink, Bruno; Böhm, Dieter; Jäkel, Alexander; Koschker, Ann-Cathrin; Schweizer, Rüdiger; Vogt, Anja; Parhofer, Klaus; König, Wolfgang; Reinhard, Wibke; Bäßler, Andrea; Stadelmann, Alexander; Schrader, Volker; Katzmann, Julius; Tarr, Adrienne; Steinhagen-Thiessen, Elisabeth; Kassner, Ursula; Paulsen, Gerret; Homberger, Jürgen; Zemmrich, Claudia; Seeger, Wolfgang; Biolik, Kathrin; Deiss, Dorothee; Richter, Corinna; Pantchechnikova, Elina; Dorn, Elena; Schatz, Ulrike; Julius, Ulrich; Spens, Antje; Wiesner, Tobias; Scholl, Michael; Rizos, Christos V.; Sakkas, Nikolaos; Elisaf, Moses; Skoumas, Ioannis; Tziomalos, Konstantinos; Rallidis, Loukianos; Kotsis, Vasileios; Doumas, Michalis; Athyros, Vasileios; Skalidis, Emmanouil; Kolovou, Genovefa; Garoufi, Anastasi

Searching for VHE gamma-ray emission associated with IceCube neutrino alerts using FACT, H.E.S.S., MAGIC, and VERITAS

The realtime follow-up of neutrino events is a promising approach to search for astrophysical neutrino sources. It has so far provided compelling evidence for a neutrino point source: the flaring gamma-ray blazar TXS 0506+056 observed in coincidence with the high-energy neutrino IceCube-170922A detected by IceCube. The detection of very-high-energy gamma rays (VHE, E&gt;100GeV E &gt; 100 G e V ) from this source helped establish the coincidence and constrained the modeling of the blazar emission at the time of the IceCube event. The four major imaging atmospheric Cherenkov telescope arrays (IACTs) - FACT, H.E.S.S., MAGIC, and VERITAS - operate an active follow-up program of target-of-opportunity observations of neutrino alerts sent by IceCube. This program has two main components. One are the observations of known gamma-ray sources around which a cluster of candidate neutrino events has been identified by IceCube (Gamma-ray Follow-Up, GFU). Second one is the follow-up of single high-energy neutrino candidate events of potential astrophysical origin such as IceCube-170922A. GFU has been recently upgraded by IceCube in collaboration with the IACT groups. We present here recent results from the IACT follow-up programs of IceCube neutrino alerts and a description of the upgraded IceCube GFU system