ESS - MN - Medicina Nuclear
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- 188Re-PEI-MP as potential agent for metabolic radiotherapyPublication . Ferreira, Sara; Abrantes, Ana Margarida; Metello, Luís F.; Zeevart, Jan; Louw, Werner; Dormehl, Irene D.; Botelho, Maria FilomenaIntroduction: 188Re is a promising radionuclide for metabolic therapy because of the emission of high energy beta-particles. The development of watersoluble bone-seeking polymers such as PEI-MP (polyethyleneimine, functionalised with methylphosphonate-groups) that might be labeled with 188Re are recent approaches, with a strong potential for bone cancer treatment. The aim of this study was to evaluate the efficacy of 188Re-PEI-MP, as therapeutic agent for osteosarcoma, through in vitro and in vivo models.
- 3D vs 2D Cell Cultures in the Evaluation of Radiobiological Effects of Exposition to Low Doses - Medical Imaging Levels - of Ionizing RadiationPublication . Costa, Pedro; Caires, Hugo; Lemos, Joana; Cunha, Lídia; Bravo, Joana; Bravo, Isabel; Silva, Regina; Summavielle, Teresa; Metello, Luís F.Pretending to develop advanced biological models to study biological effects of low doses of ionizing radiation and following the actual policies on Animal Sciences, based on 3 R’s Rule (to Reduce, Refine and Replace) – that limits as much as possible the application of animal models – scientific research using cellular models is constantly increasing. Nevertheless, the intrinsic limitations of actual cellular models quite often had been recognized on a significant number of papers pointing a significant number of non-concordances between results obtained using in vitro and in vivo studies. Actually, an increasing number of authors admit that three-dimensional cell culture (and spheroid cell culture in particular) could represent an interesting solution and a step further on use of cellular models. The work here to be presented reflects the first phase on the use of this methodology on the study, evaluation and quantification of cellular effects of low doses – starting on medical imaging level - of exposition to ionizing radiation.
- 45Ti - Titanium: from cyclotron production to potential applications evaluationPublication . Costa, Pedro; Metello, Luís F.; Cunha, Lídia; Lass, Piotr; Currie, Geoff; Johnson, Richard R.; Gelbart, W.; Obermair, J.; Artner, Christoph; Alves, Francisco; Naia, M. DuarteIntroduction: Thousands of radioisotopes are known and virtually all may be artificially produced, however clinical applications of PET imaging are mainly based on 18F, 11C, 13N and 68Ga. This trend could change in the near future, since several groups worldwide are busy developing very promising new entities aiming to contribute for spreading the use and efficacy of clinical diagnostic using Nuclear Medicine imaging techniques. Our group is developing 45Ti-Titanium, assuming it as a potential candidate, since presenting interesting properties: physical half-life of 3.09h, together with relevant chemical properties, that enable radiolabelling with bifunctional chelates, ligands or could even be useful for studies concerning the distribution of new titanium-based chemotherapy drugs or titanium oxide nanoparticles. Considering that data characterizing excitation functions is necessary for radionuclide optimal production, this work aims to disseminate results regarding the determination of excitation function of 45Sc(p,n)45Ti reaction, studied as a potential route to produce 45Ti in low energy cyclotrons.
- 99mTc-MAA for Lung Perfusion Scintigraphy: Impact of Counting Method on the Effective Number of Particles Administered and Particle Aggregation Over TimePublication . Costa, Pedro; Cunha, Lídia; Soares, Sofia; Mendes, Ângela; Queiroz, Ana; Nunes, Amélia; Ferreira, Elisabete; Botelho, Elisa; Sousa, Maria C.; Castro, Rosa; Pires, Laucena; João, M. Faria; Metello, Luís F.: 99mTc-MAA (macroaggregates of albumin) is the selected radiopharmaceutical for the Lung Perfusion Scintigraphy. It is retained in lung capillaries by mechanical blockage resulting in local microembolization. Care should be taken concerning not only particle size but also the number of particles administered to patients, particularly those who present with special conditions (pulmonary hypertension, shunt or lung transplant). European Pharmacopoeia only requires the assessment of particle size. This work aims to characterize particle size and particle aggregation of two commercial brands of MAA kits and to compare particle counting methods
- 99mTc-MAA for Lung Perfusion Scintigraphy: Impact of Counting Method on the Effective Number of Particles Administered and Particle Aggregation Over TimePublication . Costa, Pedro; Cunha, Lídia; Soares, Sofia; Mendes, Ângela; Queiroz, A. Isabel; Nunes, Amélia; Ferreira, Elisabete; Botelho, Elisa; Sousa, Conceição; Castro, Rosa; Pires, Laucena; João, M. Faria; Metello, Luís F.Introduction: 99mTc-MAA (macroaggregates of albumin) is the selected radiopharmaceutical for the Lung Perfusion Scintigraphy. It is retained in lung capillaries by mechanical blockage resulting in local microembolization. Care should be taken concerning not only particle size butalso the number of particles administered to patients, particularly those who present with special conditions (pulmonary hypertension, shunt or lung transplant). European Pharmacopoeia only requires the assessment of particle size. This work aims to characterize particle size and particle aggregation of two commercial brands of MAA kits and to compare particle counting methods.
- 99mTc-Technetium Shortage: old problems asking for new solutionsPublication . Metello, Luis F.Technetium 99-metastable (99mTc) is the most important radionuclide, responsible for more than 80% of applications in nuclear medicine, with more than 40 million procedures being performed each year, worldwide, in all major clinical fields. It decays with a half-life of 6.01 hours by isomeric tran sition to 99gTc, thereby emitting 140 keV gamma photons. This energy almost ideally meets the maximum sensitivity of single photon emission computed tomography (SPECT) cam era systems. In addition, the rich complex chemistry of Techne tium allows the incorporation of the radioisotope into a wide variety of ligands stabilizing the radionuclide at different oxida tion states. Thus, since the early 60s, hundreds of radiopharma ceuticals labeled with 99mTc have been developed, and some have gained significant market success. However, the main reason for the special role of Technetium in SPECT is probably the cost effectiveness and the on-demand worldwide availability of the isotope through the 99Mo/99mTc generator systems.
- Acetyl-L-Carnitine Improves Cell BioenergeticsPublication . Cunha, Lídia; Bravo, Joana; Costa, Pedro; Fernandes, Sílvia; Oliveira, Marta; Castro, Rosa; Metello, Luís F.; Summavielle, TeresaIntroduction: Acetyl-L-Carnitine (ALC), a natural occurring compound in all mammalian species, plays a variety of vital functions in the body. The most important are related to mitochondria, namely the transport of fatty acids for energy production through β oxidation and the control of acyl-CoA/CoA ratio. Due to this close interaction with cell bioenergetics, it plays a role in many diseases, especially those related to the mitochondria. We propose to characterize the action of ALC in mitochondrial bioenergetics and functional integrity.
- Actual Trends in Nuclear MedicinePublication . Vieira, Domingos; Lemos, Joana; Ferreira, Sara; Metello, Luís F.
- Actualities on Nuclear Medicine Applications in Sports MedicinePublication . Fonseca, Abigaíl; Soares, Sofia; Cunha, Lídia; Metello, Luís F.Aims: This paper aims to address some of the main possible applications of actual Nuclear Medicine Imaging techniques and methodologies in the specific context of Sports Medicine, namely in two critical systems: musculoskeletal and cardiovascular. Discussion: At the musculoskeletal level, bone scintigraphy techniques proved to be a mean of diagnosis of functional orientation and high sensibility compared with other morphological imaging techniques in the detection and temporal evaluation of pathological situations, for instance allowing the acquisition of information of great relevance in athletes with stress fractures. On the other hand, infection/inflammation studies might be of an important added value to characterize specific situations, early diagnose of potential critical issues – so giving opportunity to precise, complete and fast solutions – while allowing the evaluation and eventual optimization of training programs. At cardiovascular system level, Nuclear Medicine had proved to be crucial in differential diagnosis between cardiac hypertrophy secondary to physical activity (the so called "athlete's heart") and hypertrophic cardiomyopathy, in the diagnosis and prognosis of changes in cardiac function in athletes, as well as in direct - and non-invasive - in vivo visualization of sympathetic cardiac innervation, something that seems to take more and more importance nowadays, namely in order to try to avoid sudden death episodes at intense physical effort. Also the clinical application of Positron Emission Tomography (PET) has becoming more and more widely recognized as promising. Conclusions: It has been concluded that Nuclear Medicine can become an important application in Sports Medicine. Its well established capabilities to early detection of processes involving functional properties allied to its high sensibility and the actual technical possibilities (namely those related with hybrid imaging, that allows to add information provided by high resolution morphological imaging techniques, such as CT and/or MRI) make it a powerful diagnostic tool, claiming to be used on an each day higher range of clinical applications related with all levels of sport activities. Since the improvements at equipment characteristics and detection levels allows the use of smaller and smaller doses, so minimizing radiation exposure it is believed by the authors that the increase of the use of NM tools in the Sports Medicine area should be considered.
- ALC Neuroprotection through autophagy and ups acitivityPublication . Bravo, Joana; Cunha, Lídia; Fernandes, Sílvia; Binienda, Zbigniew; Summavielle, TeresaAcetyl–L-carnitine (ALC) has beneficial effects in neurodegenerative diseases and was shown to be protective against exposure to methamphetamine (METH) reducing mitochondrial dysfunction and oxidative stress. However, the mechanisms underlying ALC action are still unknown, limiting its putative therapeutic use.