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1. 18th European Symposium on Radiopharmacy and Radiopharmaceuticals: Salzburg, Austria. 7-10 April 2016

Author

Radchenko, V., Engle, J. W., Roy, C., Griswold, J., Nortier, M. F., Birnbaum, E. R., Brugh, M., Mirzadeh, S., John, K. D., Fassbender, M. E., Zhai, Chuangyan, Franssen, Gerben M., Petrik, Milos, Laverman, Peter, Decristoforo, Clemens, Samia, Ait-Mohand, Véronique, Dumulon-Perreault, Brigitte, Guérin, Summer, D., Kroess, A., Rangger, C., Haas, H., Laverman, P., Gerben, F., von Guggenberg, E., Decristoforo, C., Bolzati, Cristina, Salvarese, Nicola, Refosco, Fiorenzo, Meléndez-Alafort, Laura, Carpanese, Debora, Rosato, Antonio, Saviano, Michele, Del Gatto, Annarita, Comegna, Daniela, Zaccaro, Laura, Billaud, Emilie, Ahamed, Muneer, Cleeren, Frederik, Shahbazali, Elnaz, Noël, Tim, Hessel, Volker, Verbruggen, Alfons, Bormans, Guy, Cleeren, F., Lecina, J., Koole, M., Verbruggen, A., Bormans, G., Lugatoa, B., Stucchia, S., Turollaa, E. A., Giulianoa, L., Toddea, S., Ferraboschib, P., Klok, R. P., Mooijer, M. P. J., Hendrikse, N. H., Windhorst, A. D., Collet, C., Petry, N., Chrétien, F., Karcher, G., Pellegrini-Moïse, N., Lamandé-Langle, S., Pfaff, Sarah, Philippe, Cecile, Mitterhauser, Markus, Hacker, Marcus, Wadsak, Wolfgang, Guérard, François, Lee, Yong-Sok, Gouard, Sébastien, Baidoo, Kwamena, Alliot, Cyrille, Chérel, Michel, Brechbiel, Martin W., Gestin, Jean-François, Lam, K., Chan, C., Reilly, R. M., Paillas, Salomé, Marshall, John, Pouget, Jean-Pierre, Sosabowski, Jane, Briard, Emmanuelle, Auberson, Yves P., Reilly, John, Healy, Mark, Sykes, David, Paulus, Andreas, Lichtenbelt, Wouter van Marken, Mottaghy, Felix, Bauwens, Matthias, Baranski, Ann-Christin, Schäfer, Martin, Bauder-Wüst, Ulrike, Haberkorn, Uwe, Eder, Matthias, Kopka, Klaus, Chaussard, M., Hosten, B., Vignal, N., Tsoupko-Sitnikov, V., Hernio, N., Hontonnou, F., Merlet, P., Poyet, J. L., Sarda-Mantel, L., Rizzo-Padoin, N., Cardinale, J., Schäfer, M., Benešová, M., Bauder-Wüst, U., Seibert, O., Giesel, F., Haberkorn, U., Eder, M., Kopka, K., Nematallah, Mansour, Michel, Paquette, Samia, Ait-Mohand, Véronique, Dumulon-Perreault, Roger, Lecomte, Brigitte, Guérin, Fernandez-Maza, L., Rivera-Marrero, S., Capote, A. Prats, Parrado-Gallego, A., Fernandez-Gomez, I., Balcerzyk, M., Sablon-Carrazana, M., Perera-Pintado, A., Merceron-Martinez, D., Acosta-Medina, E., Rodriguez-Tanty, C., Attili, Bala, Ahamed, Muneer, Bormans, Guy, Philippe, C., Zeilinger, M., Scherer, T., Fürnsinn, C., Dumanic, M., Wadsak, W., Hacker, M., Mitterhauser, M., Janssen, B., Vugts, D. J., Molenaar, G.T. T., Funke, U., Kruijer, P. S., Dollé, F., Bormans, G., Lammertsma, A. A., Windhorst, A. D., Vermeulen, Koen, Ahamed, Muneer, Schnekenburger, Michael, Froeyen, Mathy, Olberg, Dag Erlend, Diederich, Marc, Bormansa, Guy, Raaphorst, R. M., Luurtsema, G., Lammertsma, A. A., Elsinga, P. H., Windhorst, A D., Rotteveel, Lonneke, Funke, Uta, ten Dijke, Peter, Bogaard, Harm Jan, Lammertsma, Adriaan A., Windhorst, Albert D., Song, Lei, Able, Sarah, Falzone, Nadia, Kersemans, Veerle, Vallis, Katherine, Carta, Davide, Salvarese, Nicola, Sihver, Wiebke, Gao, Feng, Pietzsch, Hans Jürgen, Biondi, Barbara, Ruzza, Paolo, Refosco, Fiorenzo, Bolzati, Cristina, Haubner, Roland, Finkensted, Armin, Stegmair, Armin, Rangger, Christine, Decristoforo, Clemens, Zoller, Heinz, Virgolini, Irene J., Pooters, Ivo, Lotz, Maartje, Wierts, Roel, Mottaghy, Felix, Bauwens, Matthias, Forsback, Sarita, Jörgen, Bergman, Riikka, Kivelä, Karageorgou, M., Radović, M., Tsoukalas, C., Antic, B., Gazouli, M., Paravatou-Petsotas, M., Xanthopouls, S., Calamiotou, M., Stamopoulos, D., Vranješ-Durić, S., Bouziotis, P., Lunev, A. S., Larenkov, A. A., Petrosova, K. A., Klementyeva, O. E., Kodina, G. E., Kvernenes, O. H., Adamsen, T. C. H., Martin, René, Weidlich, Sebastian, Zerges, Anna-Maria, Gameiro, Cristiana, Lazarova, Neva, Müllera, Marco, Luurtsema, Gert, de Vries, Michèl, Ghyoot, Michel, van der Woude, Gina, Zijlma, Rolf, Dierckx, Rudi, Boersma, Hendrikus H., Elsinga, Philip H., Lambrecht, Fatma Yurt, Er, Ozge, Ince, Mine, Avci, Cıgır Biray, Gunduz, Cumhur, Sarı, Fatma Aslihan, Ocakoglu, Kasim, Er, Ozge, Ersoz, Onur Alp, Lambrecht, Fatma Yurt, Ince, Mine, Kayabasi, Cagla, Gunduz, Cumhur, Kniess, Torsten, Meister, Sebastian, Fischer, Steffen, Steinbach, Jörg, Ashfaq, Rabia, Iqbal, Saeed, ullah Khan, Irfan, Iglesias-Jerez, R., Martín-Banderas, L., Perera-Pintado, A., Borrego-Dorado, I., Farinha-Antunes, Ines, Kwizera, Chantal, Lacivita, Enza, Lucente, Ermelinda, Niso, Mauro, De Giorgio, Paola, Perrone, Roberto, Colabufo, Nicola A., Elsinga, Philip H., Leopoldo, Marcello, Vaulina, V. V., Fedorova, O. S., Orlovskaja, V. V., Chen, С. L., Li, G. Y., Meng, F. C., Liu, R. S., Wang, H. E., Krasikova, R. N., Meléndez-Alafort, Laura, Abozeid, Mohamed, Ferro-Flores, Guillermina, Negri, Anna, Bello, Michele, Uzunov, Nikolay, Paiusco, Martha, Esposito, Juan, Rosato, Antonio, Meléndez-Alafort, Laura, Bolzati, Cristina, Ferro-Flores, Guillermina, Salvarese, Nicola, Carpanese, Debora, Abozeid, Mohamed, Rosato, Antonio, Uzunov, Nikolay, Palmieri, L., Verbrugghen, T., Glassner, M., Hoogenboom, R., Staelens, S., Wyffels, L., Orlovskaja, V. V., Kuznetsova, O. F., Fedorova, O. S., Maleev, V. I., Belokon, Yu. N., Geolchanyan, A., Saghyan, A. S., Mu, L., Schibli, R., Ametamey, S. M., Krasikova, R. N., Revunov, Evgeny, Malmquist, Jonas, Johnström, Peter, Van Valkenburgh, Juno, Steele, Dalton, Halldin, Christer, Schou, Magnus, Osati, Samira, Paquette, Michel, Beaudoin, Simon, Ali, Hasrat, Guerin, Brigitte, Leyton, Jeffrey V., van Lier, Johan E., Di Iorio, V, Iori, M., Donati, C., Lanzetta, V., Capponi, P. C., Rubagotti, S., Dreger, T., Kunkel, F., Asti, M., Zhai, Chuangyan, Rangger, Christine, Summer, Dominik, Haas, Hubertus, Decristoforo, Clemens, Kijprayoon, Suphansa, Ruangma, Ananya, Ngokpol, Suthatip, Tuamputsha, Samart, Filp, Ulrike, Pees, Anna, Taddei, Carlotta, Pekošak, Aleksandra, Gee, Antony D., Poot, Alex J., Windhorst, Albert D., Gunay, Mine Silindir, Ozer, A. Yekta, Erdogan, Suna, Baysal, Ipek, Guilloteau, Denis, Chalon, Sylvie, Galli, Filippo, Artico, Marco, Taurone, Samanta, Bianchi, Enrica, Weintraub, Bruce D., Skudlinski, Mariusz, Signore, Alberto, Lepareur, Nicolas, Noiret, Nicolas, Hindré, François, Lacœuille, Franck, Benoist, Eric, Garin, Etienne, Trejo-Ballado, F., Zamora-Romo, E., Manrique-Arias, J. C., Gama-Romero, H M, Contreras-Castañon, G., Tecuapetla-Chantes, R. G., Avila-Rodriguez, M. A., Kvaternik, H., Hausberger, D., Zink, C., Rumpf, B., Aigner, R. M., Kvaternik, H., Hausberger, D., Rumpf, B., Aigner, R. M., Janković, Drina, Lakić, Mladen, Savić, Aleksandar, Ristić, Slavica, Nikolić, Nadežda, Vukadinović, Aleksandar, Sabo, Tibor J., Vranješ-Đurić, Sanja, Vranješ-Đurić, S., Radović, M., Janković, D., Nikolić, N., Goya, G. F., Calatayud, P., Spasojević, V., Antić, B., Goblet, David, Gameiro, Cristiana, Lazarova, Neva, Gameiro, Cristiana, Oxley, Ian, Abrunhosa, Antero, Kramer, Vasko, Vosjan, Maria, Spaans, Arnold, Vats, Kusum, Satpati, Drishty, Sarma, Haladhar D., Banerjee, Sharmila, Wojdowska, W., Pawlak, D. W., Parus, L. J., Garnuszek, P., Mikołajczak, R., Pijarowska-Kruszyna, J., Jaron, A., Kachniarz, A., Malkowski, B., Garnuszek, P., Mikolajczak, R., Ilem-Ozdemir, Derya, Caglayan-Orumlu, Oya, Asikoglu, Makbule, Ilem-Ozdemir, Derya, Caglayan-Orumlu, Oya, Asikoglu, Makbule, Eveliina, Arponen, Semi, Helin, Timo, Saarinen, Simo, Vauhkala, Esa, Kokkomäki, Pertti, Lehikoinen, De Simone, Mariarosaria, Pascali, Giancarlo, Carzoli, Ludovica, Quaglierini, Mauro, Telleschi, Mauro, Salvadori, Piero A., Lam, Phoebe, Aistleitner, Martina, Eichinger, Reinhard, Artner, Christoph, Nakka, Surendra, MC, Hemantha Kumara, Al-Qahtani, Mohammed, Al-Qahtani, Mohammed, Al-Malki, Yousif, Mambilima, N., Rubow, S. M., Berroterán-Infante, N., Hacker, M., Mitterhauser, M., Wadsak, W., Funke, Uta, Cleeren, Frederik, Lecina, Joan, Gallardo, Rodrigo, Verbruggen, Alfons M., Bormans, Guy, Ramos-Membrive, Rocío, Brotons, Ana, Quincoces, Gemma, Inchaurraga, Laura, de Redín, Inés Luis, Morán, Verónica, García-García, Berta, Irache, Juan Manuel, Peñuelas, Iván, Trabelsi, M., Cooper, M. S., Abella, Alejandra, Fuente, Teodomiro, Montellano, Antonio Jesús, Martínez, Teresa, Rabadan, Ruben, Meseguer-Olmo, Luis, Lehtiniemi, P., Yim, C., Mikkola, K., Nuutila, P., Solin, O., von Guggenberg, E., Rangger, C., Mair, C., Balogh, L., Pöstényi, Z., Pawlak, D., Mikołajczak, R., Socan, A., Peitl, P. Kolenc, Krošelj, M., Rangger, C., Decristoforo, C., Collet, C., Remy, S., Didier, R., Vergote, T., Karcher, G., Véran, N., Pawlak, D., Maurin, M., Garnuszek, P., Karczmarczyk, U., Mikołajczak, R., Fredericia, Pil, Severin, Gregory, Groesser, Torsten, Köster, Ulli, Jensen, Mikael, Leonte, R., Puicea, F. D., Raicu, A., Min, E. A., Serban, R., Manda, G., Niculae, D., Zerna, Marion, Schieferstein, Hanno, Müller, Andre, Berndt, Mathias, Yim, Cheng-Bin, Mikkola, Kirsi, Nuutila, Pirjo, Solin, Olof, Seifert, D., Ráliš, J., Lebeda, O., Selivanova, Svetlana V., Senta, Helena, Lavallée, Éric, Caouette, Lyne, Turcotte, Éric, Lecomte, Roger, Kochovska, Marina Zdraveska, Ivanovska, Emilija Janjevik, Jokic, Vesna Spasic, Ackova, Darinka Gjorgieva, Smilkov, Katarina, Makreski, Petre, Stafilov, Trajče, Janevik-Ivanovska, Emilija, Alemu, Aschalew, Muchira, Joel Munene, Wanjeh, David Mwanza, Janevik-Ivanovska, Emilija, Janevik-Ivanovska, Emilija, Zdravev, Zoran, Bhonsle, Uday, Alberto, Osso Júnior João, Duatti, Adriano, Angelovska, Bistra, Stojanovska, Zdenka, Sarafinovska, Zorica Arsova, Bosnakovski, Darko, Gorgieva-Ackova, Darinka, Smilkov, Katarina, Drakalska, Elena, Venkatesh, Meera, Gulaboski, Rubin, Colin, Didier J., Inkster, James A. H., Germain, Stéphane, Seimbille, Yann, Atiq-ur-Rehman, and Cayero-Otero

Published
2016
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6. 18F-FLT and 125I-IdUrd uptake increase in human tumour cell lines induced by the thymidylate synthase inhibitor FdUrd

Author

Viertl, D., Perillo-Adamer, F., Andre, Pierre-Alain, Ametamey, S. M., Ross, T. L., Kosinski, M., Dupertuis, Y. M., Bischof Delaloye, A., and Buchegger, Franz

Subjects
embryonic structures, cardiovascular system, ddc:616.0757
Abstract

AIM: 5-fluoro-2'-deoxyuridine (FdUrd) depletes the endogenous 5'-deoxythymidine triphosphate (dTTP) pool. We hypothesized whether uptake of exogenous dThd analogues could be favoured through a feedback enhanced salvage pathway and studied the FdUrd effect on cellular uptake of 3'-deoxy-3'-18F-fluorothymidine (18F-FLT) and 5-125I-iodo-2'-deoxyuridine (125I-IdUrd) in different cancer cell lines in parallel. METHODS: Cell uptake of 18F-FLT and 125I-IdUrd was studied in 2 human breast, 2 colon cancer and 2 glioblastoma lines. Cells were incubated with/without 1 µmol/l FdUrd for 1 h and, after washing, with 1.2 MBq 18F-FLT or 125I-IdUrd for 0.3 to 2 h. Cell bound 18F-FLT and 125I-IdUrd was counted and expressed in % incubated activity (%IA). Kinetics of 18F-FLT cell uptake and release were studied with/without FdUrd modulation. 2'-3H-methyl-fluorothymidine (2'-3H-FLT) uptake with/without FdUrd pretreatment was tested on U87 spheroids and monolayer cells. RESULTS: Basal uptake at 2 h of 18F-FLT and 125I-IdUrd was in the range of 0.8-1.0 and 0.4-0.6 Bq/cell, respectively. FdUrd pretreatment enhanced 18F-FLT and 125I-IdUrd uptake 1.2-2.1 and 1.7-4.4 fold, respectively, while co-incubation with excess thymidine abrogated all 18F-FLT uptake. FdUrd enhanced 18F-FLT cellular inflow in 2 breast cancer lines by factors of 1.8 and 1.6, respectively, while outflow persisted at a slightly lower rate. 2'-3H-FLT basal uptake was very low while uptake increase after FdUrd was similar in U87 monolayer cells and spheroids. CONCLUSIONS: Basal uptake of 18F-FLT was frequently higher than that of 125I-IdUrd but FdUrd induced uptake enhancement was stronger for 125I-IdUrd in five of six cell lines. 18F-FLT outflow from cells might be an explanation for the observed difference with 125I-IdUrd.

Published
2012

7. Efficient Synthesis of Enantiomerically Pure Thioester Precursors of [11C] MCN-5652 from Racemic MCN-5652

Author

Zessin, J., Gucker, P., Ametamey, S. M., Steinbach, J., Brust, P., Vollenweider, T. X., Johannsen, B., and Schubiger, P. A.

Abstract

An improved synthesis of the enantiomerically pure thioester precursors of [11C](+)-McN-5652 ([11C](+)-1), and [11C](-)-McN5652 ([11C](-)-1) starting from racemic McN-5652 ((±)-1) is described. The synthetic method includes the resolution of (±)-1 by repeated crystallization of the (+)- and (-)-di-p-toluoyltartrates yielding (+)-McN-5652 ((+)-1) and (-)-McN-5652 ((-)-1), each with > 98 % enantiomeric purity. S-Demethylation of (±)-1, (+)-1 and (-)-1, respectively was achieved by treatment with sodium amide at low temperatures (-78 °C) followed by conversion of the intermediate thiols 2 with acetyl chloride to give the corresponding thioester precursors (±)-3, (+)-3 or (-)-3. This demethylation method almost completely suppressed the isomerization of the pharmacologically active trans diastereomer into the inactive cis form. Chiral HPLC analyses confirmed that the S-demethylation proceeded without any racemization. 11C-Labelling of (+)-3 or (-)-3 yields enantiomerically pure [11C](+)-McN-5652 or [11C](-)-McN5652, each in 22 % radiochemical yield (decay-corrected, related to [11C]CO2) and a specific radioactivity of 74 GBq/µmol (2 Ci/µmol) at the end of synthesis (EOS).

Published
1999

8. Pharmacological Prerequisites for PET Ligands and Practical Issues in Preclinical PET Research.

Author

Stock, G., Lessl, M., Schubiger, P. A., Lehmann, L., Friebe, M., Ametamey, S. M., and Honer, M.

Abstract

The development of PET radiopharmaceuticals for the non-invasive imaging of cancerous lesions, brain receptors, transporters and enzymes started more than 25 years ago. But till today no established algorithms exist to predict the success of a PET radiopharmaceutical. PET radioligand development is a challenging endeavor and predicting the success of PET ligand can be an elusive undertaking. A large number of PET radiopharmaceuticals have been developed for imaging, but so far only a few have found application as imaging agents in vivo in humans. Typically, the potential compound selected for development usually has the desired in vitro characteristics but unknown in vivo properties. The purpose of this chapter is to highlight some of the pharmacological constraints and prerequisites. Interspecies difference in metabolism and mass effects are discussed with examples. Finally, some of the practical issues related to laboratory animal imaging using anesthetic agents are also presented. [ABSTRACT FROM AUTHOR]

Published
2007
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9. Measurements of hypoxia ([18F]-FMISO, [18F]-EF5) with positron emission tomography (PET) and perfusion using PET ([15O]-H2O) and power Doppler ultrasonography in feline fibrosarcomas.

Author

Allemann, K., Wyss, M. T., Wergin, M., Ohlerth, S., Rohrer-Bley, C., Evans, S. M., Schubiger, A. P., Ametamey, S. M., and Kaser-Hotz, B.

Subjects
HYPOXEMIA, CAT diseases, TUMORS in animals, INFLUENCE of altitude, POSITRON emission tomography, TUMOR necrosis factors, ULTRASONIC imaging
Abstract

The aim of this study was to evaluate if hypoxia in feline fibrosarcomas can be detected. This was done using positron emission tomography (PET), two hypoxia tracers and polarographic pO2 measurements. Of the seven cats included, five received [18F]-fluoromisonidazole and two 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide. Perfusion was evaluated with [15O]-H2O ( n = 4) and with contrast-enhanced power Doppler ultrasonography ( n = 5). Hypoxia was detected in three cats. Polarographic pO2 measurements did not confirm PET results. In the ultrasonographic evaluation, low vascularity and low perfusion were seen with a peripheral vascular pattern and no perfusion in the centre of the tumour. This was in contrast to the [15O]-H2O scans, where central perfusion of the tumour was also found. In conclusion, it appears that hypoxia exists in this tumour type. The presence of tumour necrosis and heterogeneous hypoxia patterns in these tumours may explain the found discrepancies between the applied techniques. [ABSTRACT FROM AUTHOR]

Published
2005
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22. 18F-FLT and 125I-IdUrd uptake increase in human tumour cell lines induced by the thymidylate synthase inhibitor FdUrd.

Author

Viertl D, Perillo-Adamer F, André PA, Ametamey SM, Ross TL, Kosinski M, Dupertuis YM, Bischof Delaloye A, and Buchegger F

Subjects
Cell Line, Tumor diagnostic imaging, Humans, Metabolic Clearance Rate drug effects, Radionuclide Imaging, Radiopharmaceuticals pharmacokinetics, Cell Line, Tumor metabolism, Dideoxynucleosides pharmacokinetics, Floxuridine administration & dosage, Idoxuridine pharmacokinetics, Nucleoside-Phosphate Kinase antagonists & inhibitors
Abstract

Aim: 5-fluoro-2'-deoxyuridine (FdUrd) depletes the endogenous 5'-deoxythymidine triphosphate (dTTP) pool. We hypothesized whether uptake of exogenous dThd analogues could be favoured through a feedback enhanced salvage pathway and studied the FdUrd effect on cellular uptake of 3'-deoxy-3'-18F-fluorothymidine (18F-FLT) and 5-125I-iodo-2'-deoxyuridine (125I-IdUrd) in different cancer cell lines in parallel., Methods: Cell uptake of 18F-FLT and 125I-IdUrd was studied in 2 human breast, 2 colon cancer and 2 glioblastoma lines. Cells were incubated with/without 1 µmol/l FdUrd for 1 h and, after washing, with 1.2 MBq 18F-FLT or 125I-IdUrd for 0.3 to 2 h. Cell bound 18F-FLT and 125I-IdUrd was counted and expressed in % incubated activity (%IA). Kinetics of 18F-FLT cell uptake and release were studied with/without FdUrd modulation. 2'-3H-methyl-fluorothymidine (2'-3H-FLT) uptake with/without FdUrd pretreatment was tested on U87 spheroids and monolayer cells., Results: Basal uptake at 2 h of 18F-FLT and 125I-IdUrd was in the range of 0.8-1.0 and 0.4-0.6 Bq/cell, respectively. FdUrd pretreatment enhanced 18F-FLT and 125I-IdUrd uptake 1.2-2.1 and 1.7-4.4 fold, respectively, while co-incubation with excess thymidine abrogated all 18F-FLT uptake. FdUrd enhanced 18F-FLT cellular inflow in 2 breast cancer lines by factors of 1.8 and 1.6, respectively, while outflow persisted at a slightly lower rate. 2'-3H-FLT basal uptake was very low while uptake increase after FdUrd was similar in U87 monolayer cells and spheroids., Conclusions: Basal uptake of 18F-FLT was frequently higher than that of 125I-IdUrd but FdUrd induced uptake enhancement was stronger for 125I-IdUrd in five of six cell lines. 18F-FLT outflow from cells might be an explanation for the observed difference with 125I-IdUrd.

Published
2012
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23. GMP-compliant radiosynthesis of [18F]altanserin and human plasma metabolite studies.

Author

Hasler F, Kuznetsova OF, Krasikova RN, Cservenyak T, Quednow BB, Vollenweider FX, Ametamey SM, and Westera G

Subjects
Chromatography, High Pressure Liquid, Fluorine Radioisotopes blood, Humans, Ketanserin blood, Ketanserin chemical synthesis, Positron-Emission Tomography, Quality Control, Fluorine Radioisotopes chemistry, Ketanserin analogs & derivatives
Abstract

[(18)F]altanserin is the preferred radiotracer for in-vivo labeling of serotonin 2A receptors by positron emission tomography (PET). We report a modified synthesis procedure suited for reliable production of multi-GBq amounts of [(18)F]altanserin useful for application in humans. We introduced thermal heating for drying of [(18)F]fluoride as well as for the reaction instead of microwave heating. We furthermore describe solid phase extraction and HPLC procedures for quantitative determination of [(18)F]altanserin and metabolites in plasma. The time course of arterial plasma activity with and without metabolite correction was determined. 90 min after bolus injection, 38.4% of total plasma activity derived from unchanged [(18)F]altanserin. Statistical comparison of kinetic profiles of [(18)F]altanserin metabolism in plasma samples collected in the course of two ongoing studies employing placebo, the serotonin releaser dexfenfluramine and the hallucinogen psilocybin, revealed the same tracer metabolism. We conclude that metabolite analysis for correction of individual plasma input functions used in tracer modeling is not necessary for [(18)F]altanserin studies involving psilocybin or dexfenfluramine treatment.

Published
2009
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24. Pharmacological prerequisites for PET ligands and practical issues in preclinical PET research.

Author

Ametamey SM and Honer M

Subjects
Anesthesia, Animals, Drug Evaluation, Preclinical, Humans, Ligands, Radiopharmaceuticals metabolism, Positron-Emission Tomography methods, Radiopharmaceuticals chemistry, Radiopharmaceuticals pharmacology
Abstract

The development of PET radiopharmaceuticals for the non-invasive imaging of cancerous lesions, brain receptors, transporters and enzymes started more than 25 years ago. But till today no established algorithms exist to predict the success of a PET radiopharmaceutical. PET radioligand development is a challenging endeavor and predicting the success of PET ligand can be an elusive undertaking. A large number of PET radiopharmaceuticals have been developed for imaging, but so far only a few have found application as imaging agents in vivo in humans. Typically, the potential compound selected for development usually has the desired in vitro characteristics but unknown in vivo properties. The purpose of this chapter is to highlight some of the pharmacological constraints and prerequisites. Interspecies difference in metabolism and mass effects are discussed with examples. Finally, some of the practical issues related to laboratory animal imaging using anesthetic agents are also presented.

Published
2007
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25. Measurements of hypoxia ([(18)F]-FMISO, [(18)F]-EF5) with positron emission tomography (PET) and perfusion using PET ([(15)O]-H(2)O) and power Doppler ultrasonography in feline fibrosarcomas*.

Author

Allemann K, Wyss MT, Wergin M, Ohlerth S, Rohrer-Bley C, Evans SM, Schubiger AP, Ametamey SM, and Kaser-Hotz B

Abstract

Abstract The aim of this study was to evaluate if hypoxia in feline fibrosarcomas can be detected. This was done using positron emission tomography (PET), two hypoxia tracers and polarographic pO(2) measurements. Of the seven cats included, five received [(18)F]-fluoromisonidazole and two 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide. Perfusion was evaluated with [(15)O]-H(2)O (n = 4) and with contrast-enhanced power Doppler ultrasonography (n = 5). Hypoxia was detected in three cats. Polarographic pO(2) measurements did not confirm PET results. In the ultrasonographic evaluation, low vascularity and low perfusion were seen with a peripheral vascular pattern and no perfusion in the centre of the tumour. This was in contrast to the [(15)O]-H(2)O scans, where central perfusion of the tumour was also found. In conclusion, it appears that hypoxia exists in this tumour type. The presence of tumour necrosis and heterogeneous hypoxia patterns in these tumours may explain the found discrepancies between the applied techniques.

Published
2005
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26. Catalytic enantioselective synthesis of 18F-fluorinated alpha-amino acids under phase-transfer conditions using (S)-NOBIN.

Author

Krasikova RN, Zaitsev VV, Ametamey SM, Kuznetsova OF, Fedorova OS, Mosevich IK, Belokon YN, Vyskocil S, Shatik SV, Nader M, and Schubiger PA

Subjects
Animals, Catalysis, Dihydroxyphenylalanine isolation & purification, Fluorine Radioisotopes chemistry, Fluorine Radioisotopes isolation & purification, Fluorine Radioisotopes pharmacokinetics, Glioma diagnostic imaging, Isomerism, Metabolic Clearance Rate, Organ Specificity, Phase Transition, Radionuclide Imaging, Radiopharmaceuticals chemical synthesis, Radiopharmaceuticals isolation & purification, Radiopharmaceuticals pharmacokinetics, Rats, Rats, Wistar, Tissue Distribution, Tyrosine isolation & purification, 2-Naphthylamine analogs & derivatives, 2-Naphthylamine chemistry, Dihydroxyphenylalanine analogs & derivatives, Dihydroxyphenylalanine chemistry, Dihydroxyphenylalanine pharmacokinetics, Glioma metabolism, Isotope Labeling methods, Naphthols chemistry, Tyrosine chemistry, Tyrosine pharmacokinetics
Abstract

We describe a new method for the asymmetric synthesis of [(18)F]fluorinated aromatic alpha-amino acids (FAA) under phase transfer conditions using achiral glycine derivative NiPBPGly and (S)-NOBIN as a novel substrate/catalyst pair. The key alkylation step proceeds under mild conditions. Substituted [(18)F]fluorobenzylbromides were prepared using nucleophilic [(18)F]fluoride and were used as alkylation agents. Two important FAA, 2-[(18)F]fluoro-L-tyrosine (2-FTYR) and 6-[(18)F]fluoro-L-3,4-dihydroxyphenylalanine (6-FDOPA), were synthesized with an ee of 92 and 96%, respectively. The total synthesis time was 110-120 min and radiochemical yields (d.c.) were 25+/-6% for 2-FTYR and 16+/-5% for 6-FDOPA.

Published
2004
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27. PET studies of 18F-memantine in healthy volunteers.

Author

Ametamey SM, Bruehlmeier M, Kneifel S, Kokic M, Honer M, Arigoni M, Buck A, Burger C, Samnick S, Quack G, and Schubiger PA

Subjects
Adult, Brain metabolism, Humans, Male, Memantine blood, Radioligand Assay, Radiopharmaceuticals blood, Receptors, N-Methyl-D-Aspartate analysis, Reference Values, Tomography, Emission-Computed, Brain diagnostic imaging, Memantine analogs & derivatives, Memantine pharmacokinetics, Radiopharmaceuticals pharmacokinetics, Receptors, N-Methyl-D-Aspartate metabolism
Abstract

Previous studies in mice and PET investigations in a Rhesus monkey showed that the regional uptake of 18F-memantine could be blocked by pharmacological doses of memantine and (+)-MK-801. In the present study, the binding characteristics of 18F-memantine was examined in five healthy volunteers. In humans, 18F-memantine was homogeneously distributed in gray matter i.e. cortex and basal ganglia regions, as well as the cerebellum. No radioactive metabolites were detected in plasma during the time-frame of the PET studies. The uptake of 18F-memantine in receptor-rich regions such as striatum and frontal cortex could be well described by a 1-tissue compartment model. The DV" values of all gray matter regions were similar and ranged from 15 to 20 ml/ml. The white matter showed lower DV" values of 15 +/- 1.4 ml/ml. These results suggest that 18F-memantine distribution in human brain does not reflect the regional NMDA receptor concentration, and therefore, this radioligand is not suitable for the PET imaging of the NMDA receptors.

Published
2002
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28. Evaluation of serotonergic transporters using PET and [11C](+)McN-5652: assessment of methods.

Author

Buck A, Gucker PM, Schönbächler RD, Arigoni M, Kneifel S, Vollenweider FX, Ametamey SM, and Burger C

Subjects
Adult, Carbon Radioisotopes, Cerebellum blood supply, Cerebellum diagnostic imaging, Female, Humans, Kinetics, Male, Serotonin Plasma Membrane Transport Proteins, Temporal Lobe blood supply, Temporal Lobe chemistry, Temporal Lobe diagnostic imaging, Thalamus blood supply, Thalamus diagnostic imaging, Carrier Proteins analysis, Cerebellum chemistry, Isoquinolines pharmacokinetics, Membrane Glycoproteins analysis, Membrane Transport Proteins, Nerve Tissue Proteins, Serotonin Antagonists, Thalamus chemistry, Tomography, Emission-Computed methods
Abstract

[11C](+)McN-5652 is an established positron emission tomography tracer used to assess serotonergic transporter density. Several methods have been used to analyze [11C](+)McN-5652 data; however, no evaluation of candidate methods has been published in detail yet. In this study, compartmental modeling using a one-tissue compartment model (K1, k2"), a two-tissue compartment model (K1 to k4), and a noncompartmental method that relies on a reference region devoid of specific binding sites were assessed. Because of its low density of serotonergic transporters, white matter was chosen as reference. Parameters related to transporter density were the total distribution volume DV" (= K1/k2", one tissue compartment), DVtot, (=K1/k1' (1 + k3/k4), two tissue compartments), and Rv (= k3'/k4, noncompartmental method). The DV", DVtot, and Rv values extended over a similar range and reflected the known pattern of serotonergic transporters. However, all parameters related to transporter density were markedly confounded by nonspecific binding. With regard to K1, the one-tissue compartment model yielded markedly lower values, which were, however, more stable. The minimal study duration needed to determine stable values for the distribution volume was approximately 60 minutes. The choice of the method to analyze [11C](+)McN-5652 data depends on the situation. Parametric maps of Rv are useful if no information on K1 is needed. If compartmental modeling is chosen, both the one- and the two-tissue compartment models have advantages. The one-tissue compartment model underestimates K1 but yields more robust values. The distribution volumes calculated with both models contain a similar amount of information. None of the parameters reflected serotonergic transporter density in a true quantitative manner, as all were confounded by nonspecific binding.

Published
2000
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29. Synthesis, radiolabelling and biological characterization of (D)-7-iodo-N-(1-phosphonoethyl)-5-aminomethylquinoxaline-2,3-dione, a glycine-binding site antagonist of NMDA receptors.

Author

Ametamey SM, Kokic M, Carrey-Rémy N, Bläuenstein P, Willmann M, Bischoff S, Schmutz M, Schubiger PA, and Auberson YP

Subjects
Animals, Anticonvulsants pharmacokinetics, Binding Sites drug effects, Female, Inhibitory Concentration 50, Iodine Radioisotopes chemistry, Kidney metabolism, Mice, Mice, Inbred BALB C, Organophosphonates metabolism, Organophosphonates pharmacokinetics, Quinoxalines metabolism, Quinoxalines pharmacokinetics, Radioligand Assay, Radiopharmaceuticals pharmacokinetics, Receptors, N-Methyl-D-Aspartate metabolism, Substrate Specificity, Tissue Distribution, Anticonvulsants chemical synthesis, Anticonvulsants pharmacology, Glycine metabolism, Organophosphonates chemical synthesis, Organophosphonates pharmacology, Quinoxalines chemical synthesis, Quinoxalines pharmacology, Radiopharmaceuticals chemical synthesis, Radiopharmaceuticals pharmacology, Receptors, N-Methyl-D-Aspartate antagonists & inhibitors
Abstract

(D)-7-Iodo-N-(1-phosphonoethyl)-5-aminomethylquinoxaline-2,3 -dione (I-PAMQX), is a potent, in vivo active antagonist acting at the glycine binding site of the NMDA receptor complex. Radioiodinated [131I]I-PAMQX was prepared with good yields and high specific activity from its 7-bromo analogue. Biodistribution studies of [131I]I-PAMQX in mice showed a relatively slow clearance from the blood. The uptake of radioactivity was highest in the kidneys, moderate in the heart, lung, liver and bones, and low in the brain.

Published
2000
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30. Radiosynthesis of [11C]brofaromine, a potential tracer for imaging monoamine oxidase A.

Author

Ametamey SM, Beer HF, Guenther I, Antonini A, Leenders KL, Waldmeier PC, and Schubiger PA

Subjects
Animals, Benzamides pharmacology, Brain diagnostic imaging, Brain drug effects, Clorgyline pharmacology, Female, Hydrocarbons, Iodinated, Indicators and Reagents, Isoenzymes analysis, Isotope Labeling, Macaca mulatta, Moclobemide, Piperidines chemical synthesis, Brain metabolism, Carbon Radioisotopes pharmacokinetics, Monoamine Oxidase analysis, Monoamine Oxidase Inhibitors chemical synthesis, Monoamine Oxidase Inhibitors pharmacology, Piperidines pharmacokinetics, Tomography, Emission-Computed methods
Abstract

Brofaromine (4-5(-methoxy-7-bromobenzofuranyl)-2-piperidine-HCl) is a potent and selective inhibitor of monoamine oxidase (MAO) A. Two methods for its synthesis and a preliminary positron emission tomography (PET) evaluation in monkey brain are described. The first method, at low carrier concentration of CO2, consisted of direct O-methylation of (4-(5-hydroxy-7-bromobenzofuranyl)-2-piperidine). The total radiochemical yield achieved ranged from 30 to 50% (from end of bombardment [EOB] and decay corrected) with an overall synthesis time of 45 min. The second approach, with high carrier amounts of CO2 arising from inherent target problems, was accomplished in a three-step route involving protection of secondary amino functionality, O-methylation and deprotection. The total radiochemical yield was 10% (from EOB and decay corrected) with a total synthesis time of 70 min. For both methods methylation was achieved using the classical methylating agent [11C]CH3I, and radiochemical purity was higher than 98%. PET evaluation of the radioligand in a Rhesus monkey showed a high uptake of radioactivity in the brain. Using the irreversible MAO-A inhibitor clorgyline and reversible MAO-A inhibitors moclobemide and brofaromine, three blockade experiments were designed to determine the extent of specific binding of [11C]brofaromine to MAO-A. No apparent decrease in accumulation of radioactivity in the monkey brain was observed when compared to a baseline scan.

Published
1996
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31. Synthesis of nor-beta-CIT, beta-CIT and trimethylstannyl-beta-CT.

Author

Ametamey SM, Halldin C, Swahn CG, Hall H, Schubiger PA, and Farde L

Subjects
Autoradiography, Brain diagnostic imaging, Brain Chemistry physiology, Cocaine chemical synthesis, Cocaine pharmacology, Dopamine Agents pharmacology, Humans, Iodine Radioisotopes, Isotope Labeling, Organometallic Compounds pharmacology, Radionuclide Imaging, Cocaine analogs & derivatives, Dopamine Agents chemical synthesis, Organometallic Compounds chemical synthesis, Trimethyltin Compounds
Published
1995
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