Parkinson’s disease (PD) is a neurodegenerative disorder marked by the progressive loss of dopaminergic neurons in the nigrostriatal pathway. The dopamine active transporter (DAT), a key protein involved in dopamine reuptake, serves as a selective biomarker for dopaminergic terminals in the striatum. DAT binding has been extensively studied using in vivo imaging techniques such as Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET). To support the design of new radiotracers targeting DAT, we employ Quantitative Structure–Activity Relationship (QSAR) analysis on a structurally diverse dataset composed of 57 compounds with known affinity constants for DAT. The best-performing QSAR model includes four molecular descriptors and demonstrates robust statistical performance: R2 = 0.7554, Q2LOO = 0.6800, and external R2 = 0.7090. These values indicate strong predictive capability and model stability. The predicted compounds are evaluated using a docking methodology to check the correct coupling and interactions with the DAT. The proposed approach—combining QSAR modeling and docking—offers a valuable strategy for screening and optimizing potential PET/SPECT radiotracers, ultimately aiding in the neuroimaging and early diagnosis of Parkinson’s disease.
La clasificación oficial de la Organización Mundial de la Salud de los tumores de tejidos hematopoyéticos y linfoides de 2016 introduce el concepto de policitemia vera (PV) enmascarada y revela que esta entidad ha sido infradiagnosticada en el pasado. Se presenta el caso de un varón de 49 años, fumador, intervenido de fractura de tobillo hace más de 15 años, remitido para valorar un posible proceso infeccioso asociado. Al no producirse separación previa de los hematíes por sedimentación durante el procedimiento de marcaje de leucocitos con 99mTc-exametazima se revisaron las causas de disminución de la velocidad de sedimentación globular. Entre ellas destacan la poliglobulia y el hábito tabáquico, ambas presentes en el paciente. Se recomendó realización de estudio hematológico que concluyó con el diagnóstico de PV. Las indicaciones del especialista en Radiofarmacia permitieron diagnosticar un caso no identificado hasta entonces, pese a que el paciente presentaba síntomas desde hacía años.
Introduction: To evaluate [18F]Fluodeoxyglucose ([18F]FDG) distribution in a murine model of myocardial infarction (MI), using Positron Emission Tomography and Computed Tomography (PET/CT) to validate this approach for use in evaluating new therapies for MI treatment. Method: MI was induced by permanent ligation of the left anterior descending coronary artery. The study included a sham group, a group with 7 days infarction (acute infarction) and another with 21 days infarction (chronic infarction). Prior to euthanasia, each group was imaged by PET/CT approximately 60 minutes after injection of [18F]FDG. Total and maximal Region of Interest and Standard Uptake Value values were obtained using CT, which enables more precise delineation of the anatomy to assess between-group differences in [18F]FDG uptake in the heart, brain and bladder. Results: Following distribution of [18F]FDG throughout the body, at 60 minutes after injection homogeneous cardiac distribution of the radiopharmaceutical was observed in the healthy group, while in the infarcted groups there was an absence of uptake in the infarct area. Using ANOVA analysis and the Kruskal-Wallis test, statistically significant differences were detected between the healthy and acute infarction groups and the acute and chronic infarction groups. There were no significant differences between the three groups in brain uptake or radiopharmaceutical clearance. Conclusions: The microPET/CT technique has the sensitivity to detect infarcted areas in the murine model. Moreover, it allows us to quantify [18F]FDG uptake and thus assess uptake by the organs in the different groups studied.
15 November 2021 in Nereis. Interdisciplinary Ibero-American Journal of Methods, Modelling and Simulation.
Liver tumors are an important health problem worldwide that on many occasions is associatedwith previous pathologies and risk factors such as viral hepatitis B and C, excessive alcohol consumptionand the increase in cases of non-alcoholic steatohepatitis, each increasingly relevant inindustrialized countries.In hepatocarcinomas not susceptible to surgical resection, brachytherapy is proving very effectiveagainst systemic and transarterial chemotherapy, developing new minimally invasiveregional treatments with less toxicity.Hepatic radioembolization is a form of brachytherapy consisting in the arterial administrationof microspheres labeled with beta negative emitting radionuclides that have little penetration inliver tissue, allowing the administration of high doses that cause cellular damage in tumor tissue,avoiding the irradiation of the contiguous healthy tissue.Among the most used microspheres are those of resin and/or glass marked with 90Y, althoughthe use of 166Ho on a biodegradable matrix of poly-L-lactic acid is currently increasing, the mainreasons lie in the special characteristics of this radionuclide, such as, lower energy of emissionbeta, shorter half-life as well as the emission of gamma photons, which allows its gammagraphicmonitoring. It is also a paramagnetic element, so it can be detected by means of magnetic resonance,facilitating simulation prior to treatment and its subsequent monitoring.