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Background and Objective: This review aims to provide an overview of novel diagnostic and therapeutic radiopharmaceuticals tested recently or used currently in genitourinary cancers within prospective phase 1-2 clinical trials, summarizing progresses and future directions., Methods: A systematic search was conducted using the PubMed/MEDLINE and ClinicalTrials.gov databases for original prospective research studies following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines., Key Findings and Limitations: Forty-six papers were systematically reviewed; 74 ongoing clinical trials were identified. The results of 27 novel radiopharmaceuticals (ie, not approved by the Food and Drug Administration/European Medicines Agency and not listed in the Pharmacopeia) prospectively investigated in genitourinary cancers, mostly prostate, for diagnostic, theranostic, or therapeutic purposes (21, one, and five of the 27 radiopharmaceuticals, respectively) over the past 5 yr were presented. Most were prostate-specific membrane antigen-targeting agents (17/27); other targets included gastrin-releasing peptide receptor, carbonic anhydrase IX, Cu, six transmembrane epithelial antigen of the prostate 1, tumor-associated glycoprotein 42, and urokinase-type plasminogen activator receptor. Ongoing research confirms the same trend. Fibroblast activation protein inhibitor, PD-L1, CD8, nectin-4, and HER2 are other targets under investigation. Among the 22 ongoing therapeutic trials (out of the 74 ongoing clinical trials), targeted alpha therapy is being explored in 12, and five are evaluating combinations of radioligand therapy with other treatments. We confirmed the safety of radiopharmaceuticals (regardless of the diagnostic/therapeutic purpose) and showed promising results in terms of diagnostic accuracy and therapeutic efficacy in genitourinary cancers., Conclusions and Clinical Implications: There continues to be expansion in radiopharmaceutical approaches to genitourinary cancers, reflecting a strong emphasis on improving tumor detection and treatment, which will likely impact future management across the disease spectrum, with the potential for improved patient care and outcomes., (Copyright © 2024 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

A key focus of cardiovascular medicine is the detection, treatment, and prevention of disease, with a move towards more personalized and patient-centred treatments. To achieve this goal, novel imaging approaches that allow for early and accurate detection of disease and risk stratification are needed. At present, the diagnosis, monitoring, and prognostication of thrombotic cardiovascular diseases are based on imaging techniques that measure changes in structural anatomy and biological function. Molecular imaging is emerging as a new tool for the non-invasive detection of biological processes, such as thrombosis, that can improve identification of these events above and beyond current imaging modalities. At the forefront of these evolving techniques is the use of high-sensitivity radiotracers in conjunction with positron emission tomography imaging that could revolutionise current diagnostic paradigms by improving our understanding of the role and origin of thrombosis in a range of cardiovascular diseases., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Poly (ADP-ribose) polymerases (PARPs) constitute of 17 members that are associated with divergent cellular processes and play a crucial role in DNA repair, chromatin organization, genome integrity, apoptosis, and inflammation. Multiple lines of evidence have shown that activated PARP1 is associated with intense DNA damage and irritating inflammatory responses, which are in turn related to etiologies of various neurological disorders. PARP1/2 as plausible therapeutic targets have attracted considerable interests, and multitudes of PARP1/2 inhibitors have emerged for treating cancer, metabolic, inflammatory, and neurological disorders. Furthermore, PARP1/2 as imaging targets have been shown to detect, delineate, and predict therapeutic responses in many diseases by locating and quantifying the expression levels of PARP1/2. PARP1/2-directed noninvasive positron emission tomography (PET) has potential in diagnosing and prognosing neurological diseases. However, quantitative PARP PET imaging in the central nervous system (CNS) has evaded us due to the challenges of developing blood-brain barrier (BBB) penetrable PARP radioligands. Here, we review PARP1/2's relevance in CNS diseases, summarize the recent progress on PARP PET and discuss the possibilities of developing novel PARP radiotracers for CNS diseases.

In vivo measurements of the deposition of an inhaled radiolabeled pharmaceutic have provided useful information related to the inhaler efficiency for depositing drug in the lung. A number of labeling techniques have been developed and applied to pharmaceutical aerosols delivered by pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs) and nebulizers; the choice of radiotracer depends on the type of imaging study being performed and the equipment used to image the lung. Preparation, validation and calibration of the radiolabeled pharmaceutical product is key to successful interpretation of the imaging study. When imaging a subject after inhalation of a radiolabeled formulation, it is the radioactivity that is detected and measured by the scanner; absolute amounts of deposited drug are inferred from the counts of radioactivity in the lung and other regions, based on the assumption that there is a 1:1 relationship between the two components—drug and radioactivity. This relationship holds true for direct-labeled PET products or for those formulations where a firm bond can be demonstrated between the drug and radiotracer for the time taken to acquire all the images. This chapter will discuss radiolabeling methods applied to therapeutic aerosols for the purpose of determining the deposition efficiency of these aerosols in the lung. The techniques apply to both in vivo studies in man and in animal models, and to some extent to in vitro models. [ABSTRACT FROM AUTHOR]

We hereby propose the use of stable, biocompatible, and uniformly sized polymeric micelles as high-radiotracer-payload carriers at region-of-interest with negligible background activity due to no or low offsite radiolysis. We modified glycol chitosan (GC) polymer with varying levels of palmitoylation (P) and quaternization (Q). Quaternary ammonium palmitoyl glycol chitosan (GCPQ) with a Q:P ratio of 9:35 (Q9P35GC) offers >99% biocompatibility at 10 mg mL−1. Q9P35GC micelles exhibit >99% 99mTechnetium (99mTc) radiolabeling via the stannous chloride reduction method without heat. The 99mTc-Q9P35GC micelles (65 ± 3 nm) exhibit >98% 6 h serum stability at 37 °C and 7 day of radiochemical stability at 25 °C. HepG2 cells show a higher uptake of FITC-Q9P35GC than Q13P15GC and Q20P15GC. The in vivo 24 h organ cumulated activity (MBq h) order follows: liver (234.4) > kidneys (60.95) > GIT (0.73) > spleen (88.84). The liver to organ ratio remains higher than 2.4, rendering a better contrast in the liver. The radiotracer uptake decreases significantly in fibrotic vs. normal liver, whereas a blocking study with excess Q9P35GC significantly decreases the radiotracer uptake in a healthy vs. fibrotic liver. FITC-Q9P35GC shows in vivo hepato-specific uptake. Radiotracer liver uptake profile follows reversible binding kinetics with data fitting to two-tissue compartmental (2T), and graphical Ichise multilinear analysis (MA2) with lower AIC and higher R2 values, respectively. The study concludes that 99mTc-Q9P35GC can be a robust radiotracer for noninvasive hepatocyte function assessment and diagnosis of liver fibrosis. Furthermore, its multifunctional properties enable it to be a promising platform for nanotheranostic applications. [ABSTRACT FROM AUTHOR]

A series of vasopressin receptor V1a ligands have been synthesized for positron emission tomography (PET) imaging. The lead compound (1S,5R)-1 ((4-(1H-indol-3-yl)-3-methoxyphenyl) ((1S,5R)-1,3,3-trimethyl-6-azabicyclo[3.2.1]octan-6-yl)methanone) and its F-ethyl analog 6c exhibited the best combination of high binding affinity and optimal lipophilicity within the series. (1S,5R)-1 was radiolabeled with 11C for PET studies. [11CH3](1S,5R)-1 readily entered the mouse (4.7% ID/g tissue) and prairie vole brains (∼2% ID/g tissue) and specifically (30-34%) labeled V1a receptor. The common animal anesthetic Propofol significantly blocked the brain uptake of [11CH3](1S,5R)-1 in the mouse brain, whereas anesthetics Ketamine and Saffan increased the uptake variability. Future PET imaging studies with V1a radiotracers in non-human primates should be performed in awake animals or using anesthetics that do not affect the V1a receptor.

Multiple myeloma (MM) is a neoplastic plasma cell proliferative disorder characterized by various osteolytic bone destruction as a radiological morphological marker. Functional imaging, particularly nuclear medicine imaging, is a promising method to visualize disease processes before the appearance of structural changes by targeting specific biomarkers related to metabolism ability, tumor microenvironment as well as neoplastic receptors. In addition, by targeting particular antigens with therapeutic antibodies, immuno-PET imaging can support the development of personalized theranostics. At present, various imaging agents have been prepared and evaluated in MM at preclinical and clinical levels. A summary overview of molecular functional imaging in MM is provided, and commonly used radiotracers are characterized.

Radioactive sealed sources and radiotracer techniques are used to diagnose industrial process units. This work introduces a workspace to simulate four sealed sources and radiotracer applications, namely, gamma scanning of distillation columns, gamma scanning of pipes, gamma transmission tomography, and radiotracer flow rate measurements. The workspace was created in Geant4 Application for Tomographic Emission (GATE) simulation toolkit and was called Industrial Radioisotope Applications Virtual Laboratory. The flexibility of GATE and the fact that it is an open-source software render it advantageous to radioisotope technology practitioners, educators, and students. The comparison of the simulation results with experimental results that are available in the literature showed the effectiveness of the virtual laboratory.

5-Chloro-2-methyl-4-isothiazolin-3-one (CMIT) and 2-methyl-4-isothiazolin-3-one (MIT) used as preservatives in various products, including humidifier disinfectants, presents substantial health hazards. This research delves into the toxicological assessments of CMIT/MIT in the respiratory system using animal models. Through the synthesis of radiolabeled [14C]CMIT and [14C]MIT, we investigated the biological uptake and in vivo behaviors of CMIT/MIT in the respiratory tissues following intratracheal exposure. Quantitative whole-body autoradiography (QWBA) revealed significant persistence of CMIT/MIT in lung tissue. In addition, radio high-performance liquid chromatography (radio-HPLC) with tandem mass spectrometry (LC-MS/MS) was employed for metabolite profiling and identification. Notably, around 28% of the radiolabel was retained in tissue after the extraction step, suggesting covalent binding of CMIT/MIT and their metabolites with pulmonary biomolecules. This observation demonstrates the propensity of the electrophilic isothiazolinone ring in CMIT/MIT to undergo chemical interactions with biothiols in proteins and enzymes, fostering irreversible alterations of biomolecules. Such accumulations of transformations could result in direct toxicity at both cellular and organ levels. Additionally, the detection of metabolites, including a MIT dimer conjugated with glutathione (GSH), as analyzed by mass spectrometry indicates the possible reduction of cellular GSH levels and subsequent oxidative stress. This investigation offers an in-depth insight into the toxic mechanisms of CMIT/MIT, underlying their capability to engage in complex formations with biomacromolecules and induce pronounced respiratory toxicity. These results highlight the imperative for stringent safety assessments of these chemicals, advocating for improved public health and safety measures in the use of chemicals. [Display omitted] • The radiolabeled CMIT and MIT were synthesized using radioactive carbon (14C). • The SUV of CMIT/MIT in lung was determined to be 6.01 after 0.083 h post exposure. • In the analysis of metabolites, the parent structures of CMIT/MIT were not observed. • Some metabolites were found to be conjugated with glutathione. • Approximately 28% of the radiolabel was bound to pulmonary biomolecules. [ABSTRACT FROM AUTHOR]

α‐Synucleinopathies including idiopathic Parkinson's disease, dementia with Lewy bodies and multiple systems atrophy share overlapping symptoms and pathological hallmarks. Selective neurodegeneration and Lewy pathology are the main hallmarks of α‐synucleinopathies. Currently, there is no imaging biomarker suitable for a definitive early diagnosis of α‐synucleinopathies. Although dopaminergic deficits detected with single‐photon emission computed tomography (SPECT) and positron emission tomography (PET) radiotracers can support clinical diagnosis by confirming the presence of dopaminergic neurodegeneration, dopaminergic imaging cannot visualize the preceding disease process, nor distinguish α‐synucleinopathies from tauopathies with dopaminergic neurodegeneration, especially at early symptomatic disease stage when clinical presentation is often overlapping. Aggregated α‐synuclein (αSyn) could be a suitable imaging biomarker in α‐synucleinopathies, because αSyn aggregation and therefore, Lewy pathology is evidently an early driver of α‐synucleinopathies pathogenesis. Additionally, several antibodies and small molecule compounds targeting aggregated αSyn are in development for therapy. However, there is no way to directly measure if or how much they lower the levels of aggregated αSyn in the brain. There is clearly a paramount diagnostic and therapeutic unmet medical need. To date, aggregated αSyn and Lewy pathology inclusion bodies cannot be assessed ante‐mortem with SPECT or PET imaging because of the suboptimal binding characteristics and/or physicochemical properties of current radiotracers. The aim of this narrative review is to highlight the suitability of aggregated αSyn as an imaging biomarker in α‐synucleinopathies, the current limitations with and lessons learned from αSyn radiotracer development, and finally to propose antibody‐based ligands for imaging αSyn aggregates as a complementary tool rather than an alternative to small molecule ligands. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society. [ABSTRACT FROM AUTHOR]

El abordaje quirúrgico de las distintas enfermedades, no solo oncológicas, ha evolucionado. Como ha sido acuñado de forma muy gráfica por el grupo de Veronesi, estamos pasando de los «tratamientos máximos tolerables a los mínimos eficaces» y este recorrido no puede ser llevado a cabo de otra forma que mediante un planteamiento de trabajo multidisciplinar y multimodalidad. Obligatoriamente multidisciplinar porque es necesaria la colaboración entre cirujanos, oncólogos, radiólogos, médicos nucleares, patólogos y todo aquel relacionado con el seguimiento de los pacientes, y obligatoriamente multimodalidad porque nos debemos encaminar hacia una cirugía de precisión a la medida de cada paciente en la que, por parte de la Medicina Nuclear, tiene mucho que decir la imagen híbrida (SPECT/TC y PET/TC), los trazadores bimodales, el empleo de nuevos aliados como la ecografía o nuestra propia adaptación a la cirugía robótica. Todo un amplio abanico de posibilidades construido a partir de un sólido cimiento como es la gammagrafía preoperatoria, que posibilita la identificación de los tejidos diana y cuyo conocimiento previo a la intervención permite plantear el abordaje quirúrgico necesario para cada paciente. The surgical approach to different pathologies, not only oncological, has evolved. As Veronesi's group has coined very graphically, we are moving from "maximum tolerable treatments to minimum effective treatments" and this journey cannot be carried out in any other way than through a multidisciplinary and multimodality approach. Multidisciplinary, because collaboration between surgeons, oncologists, radiologists, nuclear physicians, pathologists, and all those involved in patient follow-up is necessary, and multimodality, because we must move towards precision surgery tailored to each patient in which, on the part of Nuclear Medicine, hybrid imaging (SPECT/CT and PET/CT), bimodal tracers, the use of new allies such as ultrasound or our own adaptation to robotic surgery have a great deal to say. A wide range of possibilities is built on the solid foundation of preoperative scintigraphy, which makes it possible to identify the target tissues and whose knowledge prior to surgery allows the necessary surgical approach to be considered for each patient. [ABSTRACT FROM AUTHOR]

Opinion statement: Neuroendocrine neoplasms (NEN) are a heterogeneous group of tumours derived from cells of neuroendocrine origin and can potentially arise everywhere in the human body. The diagnostic assessment of NEN can be performed using a variety of PET radiopharmaceuticals. Well-differentiated NEN (NET) present a high expression of SSTR (somatostatin receptors) and can therefore be studied with 68Ga-DOTA-peptides ([68Ga]Ga-DOTANOC, [68Ga]Ga-DOTATOC, [68Ga]Ga-DOTATATE). Current guidelines recommend the use of SSTR imaging to assess disease extension at staging/restaging, follow-up, assessment of response to therapy and selection of patients who may benefit from radionuclide therapy (PRRT). [18F]F-FDG is used for the assessment of high-grade tumours (high-grade G2, G3 and NEC) and in every case, there is one or more mismatched lesions between diagnostic CT (positive) and SSTR-PET/CT (negative). [18F]F-DOPA is currently used for the assessment of medullary thyroid carcinoma, neuroblastoma, primary pheochromocytoma and abdominal paraganglioma. In recent years, however, several new tracers were designed exploiting the many potential targets of the neuroendocrine cell and were employed in clinical trials for both imaging and therapy. Currently, the real-life clinical impact of these tracers is still mostly not known; however, the favourable biodistribution (e.g. [68Ga]Ga-FAPI, SSTR antagonists) and the possibility to use new theranostic pairs may provide novel diagnostic as well as therapeutic options (e.g. [68Ga]Ga-PSMA, [64Cu]Cu-SARTATE, [68Ga]Ga-CXCR4) for NEN patients. [ABSTRACT FROM AUTHOR]

Several radioisotopes of iodine (123I, 124I, 125I, and 131I) are available for medical use. One of them can be used, depending on the application, for radioiodine labeling of New Chemical Entities (NCEs) and biomolecules (peptides, proteins, protein fragments, monoclonal antibodies, etc.) for the development of novel imaging and therapeutic pharmaceuticals. Direct, using inorganic and organic oxidizing agents and enzyme catalysts, and indirect, using prosthetic groups, radioiodine-labeling methods have been used routinely in the past. In this report, a comprehensive review of the physical properties of various iodine radionuclides, their medical applications, and a summary of various radioiodine labeling reagents and methods for NCEs and biomolecules are provided. [ABSTRACT FROM AUTHOR]

Breast cancer is one of the most common malignancies in women, with high morbidity and mortality rates. In breast cancer, the use of novel radiopharmaceuticals in nuclear medicine can improve the accuracy of diagnosis and staging, refine surveillance strategies and accuracy in choosing personalized treatment approaches, including radioligand therapy. Nuclear medicine thus shows great promise for improving the quality of life of breast cancer patients by allowing non-invasive assessment of the diverse and complex biological processes underlying the development of breast cancer and its evolution under therapy. This review aims to describe molecular probes currently in clinical use as well as those under investigation holding great promise for personalized medicine and precision oncology in breast cancer.

Many neurodegenerative diseases are neuropathologically characterized by neuronal loss, gliosis, and the deposition of misfolded proteins such as β-amyloid (Aβ) plaques and tau tangles in Alzheimer's disease (AD). In postmortem AD brains, reactive astrocytes and activated microglia are observed surrounding Aβ plaques and tau tangles. These activated glial cells secrete pro-inflammatory cytokines and reactive oxygen species, which may contribute to neurodegeneration. Therefore, in vivo imaging of glial response by positron emission tomography (PET) combined with Aβ and tau PET would provide new insights to better understand the disease process, as well as aid in the differential diagnosis, and monitoring glial response disease-specific therapeutics. There are two promising targets proposed for imaging reactive astrogliosis: monoamine oxidase-B (MAO-B) and imidazoline2 binding site (I2BS), which are predominantly expressed in the mitochondrial membranes of astrocytes and are upregulated in various neurodegenerative conditions. PET tracers targeting these two MAO-B and I2BS have been evaluated in humans. [18F]THK-5351, which was originally designed to target tau aggregates in AD, showed high affinity for MAO-B and clearly visualized reactive astrocytes in progressive supranuclear palsy (PSP). However, the lack of selectivity of [18F]THK-5351 binding to both MAO-B and tau, severely limits its clinical utility as a biomarker. Recently, [18F]SMBT-1 was developed as a selective and reversible MAO-B PET tracer via compound optimization of [18F]THK-5351. In this review, we summarize the strategy underlying molecular imaging of reactive astrogliosis and clinical studies using MAO-B and I2BS PET tracers. [ABSTRACT FROM AUTHOR]

In oncology, biomarker research aimed to provide insights on cancer biology via positron emission tomography (PET) and single photon emission tomography (SPECT) imaging has seen an incredible growth in the past two decades. Despite the increased number of publications on PET/SPECT radiopharmaceuticals, the field lacked standardization of in vitro and in vivo parameters necessary for the characterization of any radiotracer. Through the efforts of the World Molecular Imaging Society Education Committee, this white paper lays down validation studies that are essential to chemically and biologically characterize new radiopharmaceuticals derived from small molecules, peptides or proteins. Finally, a brief overview of the steps toward translation is also presented. Herein, we discuss the following: Chemistry and radiochemistry metrics to establish the identity of the imaging agent. In vitro and in vivo studies to examine the radiotracer's mechanism of action, which includes target specificity, pharmacokinetics and in vivo metabolism. [ABSTRACT FROM AUTHOR]

Purpose: Imaging of PARP expression has emerged as valuable strategy for prediction of tumor malignancy. While [18F]PARPi and [18F]FTT are already in clinical translation, both suffer from mainly hepatobiliary clearance hampering their use for detection of abdominal lesions, e.g., liver metastases. Our novel radiotracer [18F]FPyPARP aims to bridge this gap with a higher renal clearance and an easily translatable synthesis route for potential clinical application. Methods: We developed a less lipophilic variant of [18F]PARPi by exchange of the fluorobenzoyl residue with a fluoronicotinoyl group and automated the radiosyntheses of the three radiotracers. We then conducted a comparative side-by-side study of [18F]PARPi, [18F]FPyPARP, and [18F]FTT in NOD.CB17-Prkdcscid/J mice bearing HCC1937 xenografts to assess xenograft uptake and pharmacokinetics focusing on excretion pathways. Results: Together with decent uptake of all three radiotracers in the xenografts (tumor-to-blood ratios 3.41 ± 0.83, 3.99 ± 0.99, and 2.46 ± 0.35, respectively, for [18F]PARPi, [18F]FPyPARP, and [18F]FTT), a partial shift from hepatobiliary to renal clearance of [18F]FPyPARP was observed, whereas [18F]PARPi and [18F]FTT show almost exclusive hepatobiliary clearance. Conclusion: These findings imply that [18F]FPyPARP is an alternative to [18F]PARPi and [18F]FTT for PET imaging of PARP enzymes. [ABSTRACT FROM AUTHOR]

Advancements in brain imaging techniques have emerged as a significant tool in detecting Alzheimer's disease (AD) progression. The complicated cascade of AD progression can be detected using radio imaging, especially with Positron emission tomography (PET). The review focus on recently introduced investigational PET tracers targeting neurofibrillary tau aggregates found typically in AD. Herein, we also address the use of different PET tracers and the clinical implementation of established and newer generation tracers. This review also intends to discuss the importance of several PET radiotracers and challenges in PET imaging. • PET tracers play an important role in understanding AD progression. • Molecular PET tracers are a helpful tool to assess neuronal circuits. • PET tracers can be used to detect the alteration of toxic proteoforms in AD. • Engineering PET tracers would allow better adaptation in the early diagnosis of AD. [ABSTRACT FROM AUTHOR]

Evolving scientific evidence has begun to point towards hyperphosphorylated tau as a major neurotoxic component in the pathophysiological development of many major neurodegenerative conditions. In response to a need for accurate and reliable diagnosis and disease monitoring in clinical and trial settings, there has been great effort put into the development of tau radiotracers. While first-generation and second-generation radiotracers have provided a basis for assessing tau, concerns of inadequate specificity and selectivity have continued to motivate further study of these radiotracers and the development of novel radiopharmaceuticals. Given the prospective scientific and clinical value of a valid tau radiotracer, the molecular neuroimaging community must be aware of the most recent developments in the realm of tau radiotracer development. This brief review article will critically overview the most established tau radiotracers and, most importantly, concentrate on the progress of more recently developed tau radiotracers. [ABSTRACT FROM AUTHOR]

In chemical processes it is essential that the flow in the process is accurately defined. Fluid velocity measurements are important for fluid flow quality performance in flow systems. This study focuses on determination of the volumetric flow rate and its standard (relative) deviation for calibration of conventional flow meters by using a radiotracer approach. The measurements for flow meter calibration were performed at a pilot-scale flow rig using Technetium-99 m (99mTc) as a radiotracer in the form of pertechnetate ion (99mTcO4-). The measured data were analyzed, and precision of the experimental setup was investigated under two different approaches – IAEA’s RTD software and sum approximation of raw data. For the first time, the variation of standard deviation of calculated flow rate with the injection volume and activity of the radiotracer was determined. Plug flow with axial dispersion was used to simulate the measured RTD curves and investigate the flow dynamics of the flowing water. The results of the study have shown the possibility of in situ calibration of flow meters with a relative error lower than 1 %. They also revealed a slight dependency of the precision of output results on the injection volume as well as similar results for manual and specialized RTD software data processing.

Many neurodegenerative diseases are neuropathologically characterized by neuronal loss, gliosis, and the deposition of misfolded proteins such as β-amyloid (Aβ) plaques and tau tangles in Alzheimer’s disease (AD). In postmortem AD brains, reactive astrocytes and activated microglia are observed surrounding Aβ plaques and tau tangles. These activated glial cells secrete pro-inflammatory cytokines and reactive oxygen species, which may contribute to neurodegeneration. Therefore, in vivo imaging of glial response by positron emission tomography (PET) combined with Aβ and tau PET would provide new insights to better understand the disease process, as well as aid in the differential diagnosis, and monitoring glial response disease-specific therapeutics. There are two promising targets proposed for imaging reactive astrogliosis: monoamine oxidase-B (MAO-B) and imidazoline2 binding site (I2BS), which are predominantly expressed in the mitochondrial membranes of astrocytes and are upregulated in various neurodegenerative conditions. PET tracers targeting these two MAO-B and I2BS have been evaluated in humans. [18F]THK-5351, which was originally designed to target tau aggregates in AD, showed high affinity for MAO-B and clearly visualized reactive astrocytes in progressive supranuclear palsy (PSP). However, the lack of selectivity of [18F]THK-5351 binding to both MAO-B and tau, severely limits its clinical utility as a biomarker. Recently, [18F]SMBT-1 was developed as a selective and reversible MAO-B PET tracer via compound optimization of [18F]THK-5351. In this review, we summarize the strategy underlying molecular imaging of reactive astrogliosis and clinical studies using MAO-B and I2BS PET tracers.

PET/CT is a commonly used modality in cancer imaging, as it can help in diagnosis, staging and assessment of treatment response in many cancer types. A better understanding of the tumor microenvironment and identification of multiple selective targets are promoting further investigation into different radiotracers for diagnosis and therapy. In the past few decades many radiopharmaceuticals have emerged for specific oncologic indications providing superior detection rate than some morphologic modalities. The purpose of this review is to provide an update on the most current radiopharmaceuticals used in cancer imaging including the mechanism of action, indications and pitfalls.

Abstract Introduction A rapid transition from a clinical‐based classification to a pathology‐based classification of neurodegenerative conditions, largely promoted by the increasing availability of imaging biomarkers, is emerging. The Framework for Innovative Multi‐tracer molecular Brain Imaging, funded by the EU Joint Program ‐ Neurodegenerative Disease Research 2016 “Working Groups for Harmonisation and Alignment in Brain Imaging Methods for Neurodegeneration,” aimed at providing a roadmap for the applications of established and new molecular imaging techniques in dementia. Methods We consider current and future implications of adopting a pathology‐based framework for the use and development of positron emission tomography techniques. Results This approach will enhance efforts to understand the multifactorial etiology of Alzheimer's disease and other dementias. Discussion The availability of pathology biomarkers will soon transform clinical and research practice. Crucially, a comprehensive understanding of strengths and caveats of these techniques will promote an informed use to take full advantage of these tools.

Introduction: Assessing the potential sources of bias and variability of the Centiloid (CL) scale is fundamental for its appropriate clinical application., Methods: We included 533 participants from AMYloid imaging to Prevent Alzheimer's Disease (AMYPAD DPMS) and Alzheimer's Disease Neuroimaging Initiative (ADNI) cohorts. Thirty-two CL pipelines were created using different combinations of reference region (RR), RR and target types, and quantification spaces. Generalized estimating equations stratified by amyloid positivity were used to assess the impact of the quantification pipeline, radiotracer, age, brain atrophy, and harmonization status on CL., Results: RR selection and RR type impact CL the most, particularly in amyloid-negative individuals. The standard CL pipeline with the whole cerebellum as RR is robust against brain atrophy and differences in image resolution, with 95% confidence intervals below ± 3.95 CL for amyloid beta positivity cutoffs (CL < 24)., Discussion: The standard CL pipeline is recommended for most scenarios. Confidence intervals should be considered when operationalizing CL cutoffs in clinical and research settings., Highlights: We developed a framework for evaluating Centiloid (CL) variability to different factors. Reference region selection and delineation had the highest impact on CL values. Whole cerebellum (WCB) and whole cerebellum plus brainstem (WCB+BSTM) as reference regions yielded consistent results across tracers. The standard CL pipeline is robust against atrophy and image resolution variation. Estimated within- and between-pipeline variability (95% confidence interval) in absolute CL units., (© None The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Positron emission tomography imaging of misfolded proteins with high-affinity and selective radioligands has played a vital role in expanding our knowledge of neurodegenerative diseases such as Parkinson's and Alzheimer's disease. The pathogenesis of Huntington's disease, a CAG trinucleotide repeat disorder, is similarly linked to the presence of protein fibrils formed from mutant huntingtin (mHTT) protein. Development of mHTT fibril-specific radioligands has been limited by the lack of structural knowledge around mHTT and a dearth of available hit compounds for medicinal chemistry refinement. Over the past decade, the CHDI Foundation, a non-for-profit scientific management organisation has orchestrated a large-scale screen of small molecules to identify high affinity ligands of mHTT, with lead compounds now reaching clinical maturity. Here we describe the mHTT radioligands developed to date and opportunities for further improvement of this radiotracer class., (© 2024 The Authors. ChemBioChem published by Wiley-VCH GmbH.)

Atherosclerosis is a well-known disease leading to cardiovascular events, including myocardial infarction and ischemic stroke. These conditions lead to a high mortality rate, which explains the interest in their prevention, early detection, and treatment. Molecular imaging is able to shed light on the basic pathophysiological processes, such as inflammation, that cause the progression and instability of plaque. The most common radiotracers used in clinical practice can detect increased energy metabolism (FDG), macrophage number (somatostatin receptor imaging), the intensity of cell proliferation in the area (labeled choline), and microcalcifications (fluoride imaging). These radiopharmaceuticals, especially FDG and labeled sodium fluoride, can predict cardiovascular events. The limitations of molecular imaging in atherosclerosis include low uptake of highly specific tracers, possible overlap with other diseases of the vessel wall, and specific features of certain tracers’ physiological distribution. A common protocol for patient preparation, data acquisition, and quantification is needed in the area of atherosclerosis imaging research. [ABSTRACT FROM AUTHOR]

Atherosclerosis is a chronic widespread cardiovascular disease and a major predisposing factor for cardiovascular events, among which there are myocardial infarction and ischemic stroke. Atherosclerotic plaque formation is a process that involves different mechanisms, of which inflammation is the most common. Plenty of radiopharmaceuticals were developed to elucidate the process of plaque formation at different stages, some of which were highly specific for atherosclerotic plaque. This review summarizes the current nuclear medicine imaging landscape of preclinical and small-scale clinical studies of these specific RPs, which are not as widespread as labeled FDG, sodium fluoride, and choline. These include oxidation-specific epitope imaging, macrophage, and other cell receptors visualization, neoangiogenesis, and macrophage death imaging. It is shown that specific radiopharmaceuticals have strength in pathophysiologically sound imaging of the atherosclerotic plaques at different stages, but this also may induce problems with the signal registration for low-volume plaques in the vascular wall.

Background: Positron emission tomography (PET) myocardial perfusion imaging (MPI) with the novel radiopharmaceutical Fluorine-18 Flurpiridaz has been shown in Phase 1, 2, and first Phase 3 clinical studies to be safe and effective in diagnosing coronary artery disease (CAD). We describe the methodology of the second FDA-mandated phase 3 prospective, open-label, international, multi-center trial of F-18 Flurpiridaz PET MPI. Methods: The primary study end point is to assess the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD [≥ 50% by quantitative invasive coronary angiography (ICA)] in patients with suspected CAD. The secondary endpoints are to evaluate the diagnostic efficacy of F-18 Flurpiridaz PET MPI compared to Tc-99 m-labeled SPECT MPI in the detection of CAD in all patients and in the following subgroups: (1) females; (2) patients with body mass index ≥ 30 kg/m2; and (3) diabetic patients. This trial's design differs from the first phase 3 trial in that (1) comparison to SPECT is now a secondary end point; (2) patients with known CAD are excluded; and (3) both SPECT and PET MPI are performed before ICA. Conclusions: This second phase 3 study will provide additional evidence on the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD. Trial Registration Number: NCT03354273 [ABSTRACT FROM AUTHOR]

We hereby propose the use of stable, biocompatible, and uniformly sized polymeric micelles as high-radiotracer-payload carriers at region-of-interest with negligible background activity due to no or low offsite radiolysis. We modified glycol chitosan (GC) polymer with varying levels of palmitoylation (P) and quaternization (Q). Quaternary ammonium palmitoyl glycol chitosan (GCPQ) with a Q:P ratio of 9:35 (Q9P35GC) offers >99% biocompatibility at 10 mg mL−1. Q9P35GC micelles exhibit >99% 99mTechnetium (99mTc) radiolabeling via the stannous chloride reduction method without heat. The 99mTc-Q9P35GC micelles (65 ± 3 nm) exhibit >98% 6 h serum stability at 37 °C and 7 day of radiochemical stability at 25 °C. HepG2 cells show a higher uptake of FITC-Q9P35GC than Q13P15GC and Q20P15GC. The in vivo 24 h organ cumulated activity (MBq h) order follows: liver (234.4) > kidneys (60.95) > GIT (0.73) > spleen (88.84). The liver to organ ratio remains higher than 2.4, rendering a better contrast in the liver. The radiotracer uptake decreases significantly in fibrotic vs. normal liver, whereas a blocking study with excess Q9P35GC significantly decreases the radiotracer uptake in a healthy vs. fibrotic liver. FITC-Q9P35GC shows in vivo hepato-specific uptake. Radiotracer liver uptake profile follows reversible binding kinetics with data fitting to two-tissue compartmental (2T), and graphical Ichise multilinear analysis (MA2) with lower AIC and higher R2 values, respectively. The study concludes that 99mTc-Q9P35GC can be a robust radiotracer for noninvasive hepatocyte function assessment and diagnosis of liver fibrosis. Furthermore, its multifunctional properties enable it to be a promising platform for nanotheranostic applications.

The use of radiotracers of product flow ducts from the oil and gas industry allows checking of installed flow meters and knowledge of the flow profile within the duct. The time transient method is older for the flow media and gauging of the flowmeters and lower permanence of the radioactive magazine at two different points. For the oil and gas industry, it is important that there is an average rate of 0.7%, so that this value is reached by a level of necessary care. One of the points is a correct detector / duct geometry at the two measurement points because the quality of the contents depends on the passage across a straight section of the radioactive duct. The present work has the purpose of analyzing the collimation effect of the detector signal during radiotracer during flow in a steel duct using Au198 as the radiotracer. The analysis was carried out using computer simulation using the computational code Microshield, simulating the entire face detector / shielding / collimation system of the NaI detector 2x2" and the fluid being used in conjunction with the system Glycerol in regime of turbulent flow. The study is found in the same way as the radio of the detector in the same distance of the radio reserve from the radio in the entrance to the standard of the ANP.

Single and binary titanium and silicon xerogels were prepared to evaluate and compare their sorption performance with commercial sorbents (Al2O3 and TiO2) used for the 99Mo/99mTc separation, under neutral pH and room temperature conditions. Molybdenum sorption capacities were determined by batch equilibrium systems using Mo(VI) solutions labelled with 99Mo radiotracer. Ti-xerogel showed the highest 99Mo distribution coefficient and sorption capacity, while Si-xerogel exerted null affinity. Binary xerogels and reference sorbents showed similar capacities. Additionally, Ti-xerogel, after a heating process, drastically decreased its sorption capacity. Finally, a molybdenum sorption mechanism was studied. [ABSTRACT FROM AUTHOR]

Radiopharmaceuticals are used in the diagnosis and management of various diseases. There are several reports of adverse reactions related to the use of radiopharmaceuticals, though it is not as common as conventional drugs. Adverse reactions related to radiopharmaceuticals have been not widely reported and documented. In this review, we have tried to summarize the adverse reactions associated with some of the commonly used radiopharmaceuticals. [ABSTRACT FROM AUTHOR]

This review summarizes and analyzes published medicinal chemistry data regarding physiologically active 2-arylbenzothiazoles – a promising class of antiproliferative agents and potential diagnostic agents for Alzheimer's disease. The data have been examined in the light of SAR approach to the properties of 2-arylbenzothiazoles and substances bioactivation mechanisms using labeled radiopharmaceuticals. The most promising leaders-in-class for which clinical trials have been recommended or conducted have been highlighted. Synthetic methods for the preparation of 2-arylbenzothiazoles as precursors of new-generation drugs have been analyzed in detail. Various methods for the preparation of fluorine-containing 2-arylbenzothiazoles, including synthetic pathway to antiproliferative drugs PMX 610, 5-F 203, and Phortress have been described. 2-Arylbenzothiazoles future application in biology and medicine has been discussed. [ABSTRACT FROM AUTHOR]

Purpose of Review: Pheochromocytoma and paraganglioma (PPGLs) are neuroendocrine tumors with diverse clinical presentations. PPGLs can be sporadic but often are associated with various syndromes, which can have variable clinical presentations. A thorough workup is therefore critical for staging, treatment, and follow-up. Imaging is an essential part of the workup and diagnosis of PPGLs. Recent Findings: Improvements in cross-sectional imaging with radionuclides have increased specificity and sensitivity for identifying and treating PPGLs. Furthermore, a variety of targets on PPGLs has allowed for optimal imaging with radionuclides that can be used for staging and treatment. Currently, radionuclides are being evaluated for staging and treatment of PPGLs. Summary: Developing novel radionuclides that can identify disease sites and target them simultaneously provides a potential for improving survival and outcomes in patients with PPGLs. Given the clinical diversity among PPGLs, expanding the therapeutic arsenal against locally advanced or metastatic PPGLs can allow clinicians to evaluate and treat PPGLs thoroughly. [ABSTRACT FROM AUTHOR]

Fast and straightforward incorporation of radionuclides into pharmaceutically relevant molecules is one of the main barriers to preclinical and clinical tracer research. Late-stage direct incorporation of cyclotron-produced [ 11 C]CO 2 to afford carbon-11-labeled radiopharmaceuticals has the potential to provide ready-to-inject positron emission tomography agents in less than an hour. The present work describes photocatalyzed carboxylation of alkylbenzene derivatives to afford 11 C-phenylacetic acids. Reaction conditions and scope are investigated followed by application of this methodology to the preparative radiosynthesis of [ 11 C]fenoprofen, a nonsteroidal anti-inflammatory drug., (© 2023 The Authors. Journal of Labelled Compounds and Radiopharmaceuticals published by John Wiley & Sons Ltd.)

Background: The early identification of responsive and resistant patients to androgen receptor-targeting agents (ARTA) in metastatic castration-resistant prostate cancer (mCRPC) is not completely possible with prostate-specific antigen (PSA) assessment and conventional imaging. Considering its ability to determine metabolic activity of lesions, positron emission tomography (PET) assessment might be a promising tool., Patients and Methods: We carried out a monocentric prospective study in patients with mCRPC treated with ARTA to evaluate the role of different PET radiotracers: 49 patients were randomized to receive 11 C-Choline, Fluorine 18 fluciclovine (anti-1-amino-3-18F-fluorocyclobutane-1-carboxylic acid - FACBC) ( 18 F-FACBC), or Gallium-68-prostate-specific-membrane-antigen ( 68 Ga-PSMA) PET, one scan before therapy and one 2 months later. The primary aim was to investigate the performance of three novel PET radiotracers for the early evaluation of response to ARTA in metastatic CRPC patients; the outcome evaluated was biochemical response (PSA reduction ≥50%). The secondary aim was to investigate the prognostic role of several semiquantitative PET parameters and their variations with the different radiotracers in terms of biochemical progression-free survival (bPFS) and overall survival (OS). The study was promoted by the Italian Department of Health (code RF-2016-02364809)., Results: Regarding the primary endpoint, at log-rank test a statistically significant correlation was found between metabolic tumor volume (MTV) (P = 0.018) and total lesion activity (TLA) (P = 0.025) percentage variation among the two scans with 68 Ga-PSMA PET and biochemical response. As for the secondary endpoints, significant correlations with bPFS were found for 68 Ga-PSMA total MTV and TLA at the first scan (P = 0.001 and P = 0.025, respectively), and MTV percentage variation (P = 0.031). For OS, statistically significant correlations were found for different 68 Ga-PSMA and 18 F-FACBC parameters and for major maximum standardized uptake value at the first 11 C-Choline PET scan., Conclusions: Our study highlighted that 11 C-Choline, 68 Ga-PSMA, and 18 F-FACBC semiquantitative PET parameters and their variations present a prognostic value in terms of OS and bPFS, and MTV and TLA variations with 68 Ga-PSMA PET a correlation with biochemical response, which could help to assess the response to ARTA., Competing Interests: Disclosure FM has received research support and/or honoraria from Astellas, BMS, Janssen, Ipsen, MSD, and Pfizer outside the submitted work. All other authors have declared no conflicts of interest., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Although positron emission tomography/computed tomography (PET/CT) underwent rapid growth during the last quarter-century, becoming a new standard-of-care for imaging most cancer types, CT and bone scan remained the gold standard for patients with prostate cancer. This occurred as 2-fluorine-18-fluoro-2-deoxy-d-glucose was perceived to have a limited role owing to low sensitivity in many patients. A resurgence of interest occurred with the use of fluorine-18-sodium-fluoride PET/CT as a replacement for bone scintigraphy, and then choline, fluciclovine, and dihydrotestosterone (DHT) PET/CT as prostate "specific" radiotracers. The last decade, however, has seen a true revolution with the meteoric rise of prostate-specific membrane antigen PET/CT., Competing Interests: Disclosure M.S. Hofman acknowledged philanthropic/government grant support from the Prostate Cancer Foundation, Australia funded by CANICA Oslo Norway, Peter MacCallum Foundation, Australia, Medical Research Future Fund, Movember, Australia, and the Prostate Cancer Foundation of Australia, Australia. Other funding in last 10 years: U.S. Department of Defense, United States. M.S. Hofman acknowledges research grant support (to Peter MacCallum Cancer Centre) from Novartis, Switzerland (including AAA and Endocyte), ANSTO, Australia, Bayer, Germany, Isotopia, and MIM, Australia. Consulting fees for lectures or advisory boards from Astellas and AstraZeneca in the last 2 years, and Janssen, Merck/MSD and Mundipharma in the last 5 years. J.P. Buteau receives PhD support through an Australian Government Research Training Program Scholarship. All other authors declare no relevant disclosures., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Bevacizumab is thought to normalize tumor vasculature and restore the blood-brain barrier, decreasing enhancement and peritumoral edema. Conventional measurements of tumor response rely upon dimensions of enhancing tumor. After bevacizumab treatment, glioblastomas are more prone to progress as nonenhancing tumor. The RANO (Response Assessment in Neuro-Oncology) criteria for glioma response use fluid-attenuated inversion recovery (FLAIR)/T2 hyperintensity as a surrogate for nonenhancing tumor; however, nonenhancing tumor can be difficult to differentiate from other causes of FLAIR/T2 hyperintensity (e.g., radiation-induced gliosis). Due to these difficulties, recent efforts have been directed toward identifying new biomarkers that either predict treatment response or accurately measure response of both enhancing and nonenhancing tumor shortly after treatment initiation. This will allow for earlier treatment decisions, saving patients from the adverse effects of ineffective therapies while allowing them to try alternative therapies sooner. An active area of research is the use of physiologic imaging, which can potentially detect treatment effects before changes in tumor size are evident.

Radioisotopes have been used in earth and environmental sciences for over 150 years and provide unique tools to study environmental processes in great detail from a cellular level through to an oceanic basin scale. These nuclear techniques have been employed to understand coastal and marine ecosystems via laboratory and field studies in terms of how aquatic organisms respond to environmental stressors, including temperature, pH, nutrients, metals, organic anthropogenic contaminants, and biological toxins. Global marine issues, such as ocean warming, deoxygenation, plastic pollution, ocean acidification, increased duration, and intensity of toxic harmful algal blooms (HABs), and coastal contamination are all impacting marine environments, thereby imposing various environmental and economic risks. Being able to reliably assess the condition of coastal and marine ecosystems, and how they may respond to future disturbances, can provide vital information for society in the sustainable management of their marine environments. This paper summarizes the historical use of radiotracers in these systems, describes how existing techniques of radioecological tracing can be developed for specific current environmental issues and provides information on emerging issues that would benefit from current and new radiotracer methods. Current challenges with using radioecological tracers and opportunities are highlighted, as well as opportunities to maximize the application of these methods to greatly increase the ability of environmental managers to conduct evidence-based management of coastal and marine ecosystems.

The chlordecone (CLD) and the β-hexachlorocyclohexane (β-HCH) are persistent organic pollutants with a great environmental stability that cause severe affectations to health. The concentration of these pesticides in the environment is low, which represent a problem for their determination, even for the modern analytical methods. The labeling of these compounds with an iodine radioisotope for their use as radiotracers is a potential solution to this problem. The present work studies the interaction of 1-iodochlordecone (I-CLD) and β-1-iodo-pentachlorocyclohexane (I-β-HCH) with cyclodextrins (CDs), during the formation of molecular inclusion complexes pesticide@CDs. The methodology of multiple minima hypersurfaces, quantic calculations based on density functional theory and a topologic study of electronic density were used to corroborate the stability of I-CLD@CDs and I-β-HCH@CDs complexes. Three main types of guest-host complexes in relation to the occlusion grade were observed: with total occlusion, with partial occlusion and external interaction without occlusion. The more stable complexes are obtained when the γ-CD is the host molecule. The formed complexes with radiolabelled pollutants are analogous with the ones reported in previous works. These results confirm the utility of these complexes for the removal of organochlorine pesticides from polluted water and, also, demonstrate the possibility of using the I-CLD and the I-β-HCH as possible radiotracers for these pollutants in further studies with environmental proposes. [ABSTRACT FROM AUTHOR]

The historical anthropogenic impact on sediments from the Basque Mud Patch (southern Bay of Biscay) is explored using a multidisciplinary approach including the analysis of natural (210Pb) and artificial (137Cs, 239/240Pu) radiotracers, major elements (Al, Mn), metals (Zn, Pb, Cu, Cr), Pb isotopic ratios, and foraminiferal and pollen contents. The study of three short cores (19–46 cm), despite being hindered by the effects of biomixing, allow the calculation of a sedimentation rate of 1 ± 0.1 mm yr−1. Distribution with depth of Al-normalised concentrations of metals reflects an increasing trend since 1880 CE, related to the industrialization of the Basque coastal area. According to the Sediment Quality Guidelines applied, contents of Zn and Pb appear as a potential cause of concern, given that they exceed the values from which adverse biological effects can be occasionally expected. However, foraminiferal assemblages do not show recognizable changes along the cores following increasing trace metal concentrations. Finally, pollen results reveal an increasing trend of coniferous taxa and a parallel reduction of authochthonous Deciduous Quercus , probably as a consequence of reforestation works. Data obtained confirm that effects of coastal anthropogenic activities extend to the adjacent shelf, where muddy deposits are likely to act as a trap for contaminants. [ABSTRACT FROM AUTHOR]

Herein, we report the development of an 18F‐labeled, activity‐based small‐molecule probe targeting the cancer‐associated serine hydrolase NCEH1. We undertook a focused medicinal chemistry campaign to simultaneously preserve potent and specific NCEH1 labeling in live cells and animals, while permitting facile 18F radionuclide incorporation required for PET imaging. The resulting molecule, [18F]JW199, labels active NCEH1 in live cells at nanomolar concentrations and greater than 1000‐fold selectivity relative to other serine hydrolases. [18F]JW199 displays rapid, NCEH1‐dependent accumulation in mouse tissues. Finally, we demonstrate that [18F]JW199 labels aggressive cancer tumor cells in vivo, which uncovered localized NCEH1 activity at the leading edge of triple‐negative breast cancer tumors, suggesting roles for NCEH1 in tumor aggressiveness and metastasis. [ABSTRACT FROM AUTHOR]

Focused ultrasound (FUS) is a minimally-invasive technology used for treatment of many diseases, including diseases related to the colon, uterus, prostate, and brain. Although it has been mainly used for ablative procedures, the ability of FUS to open the blood-brain barrier (BBB) presents a promising new application. However, the mechanism of BBB opening by FUS remains unclear. This review focuses on the use of FUS to open the BBB for enhancing drug delivery and investigating how Positron Emission Tomography (PET) provides insight into the underlying mechanism. Unlabelled Image • FUS may be a useful technique to enhance cerebral drug delivery. • The mechanism of BBB opening by FUS remains unclear. • The effect of FUS and microbubbles on the mechanism of BBB transporters remains undetermined. • PET may be a promising quantitative approach to assess the molecular effects of sonication. [ABSTRACT FROM AUTHOR]

Coastal sediment redeposition after resuspension events may change the sediment capacity to sequester pollutants after the formation of new sediment-water interfaces. To test this hypothesis, radiotracer experiments were performed to evaluate zinc (65Zn) and cadmium (109Cd) removal kinetics by redeposited mangrove sediments. After 24-h experiments, average inventories within redeposited sediments were close to those from control sediments (~ 20% lower in redeposited sediments), while average decreases of 41% (109Cd) and 27% (65Zn) in the half-removal times (t1/2) from overlying water were promoted by redeposited sediments in comparison with control sediments. High variability in metal removal rates, however, implied in no statistically significant differences between t1/2 values, suggesting a low influence of sediment redeposition on the metal removal capacity of mangrove sediments. More limited depth diffusion of metals was observed within redeposited sediments, always within the uppermost centimeter. Possible benefits to water quality by a slightly faster metal diffusion into redeposited sediments may be less effective due to this trend since the metal retention very close to the sediment top can facilitate new remobilization to the overlying water. [ABSTRACT FROM AUTHOR]

Cadmium is a serious environmental pollutant and its uptake by plant represents a serious health risk. Uptake, accumulation as well as sensitivity of soybean plants to metals have been shown to vary with genotype, while the dynamics of this uptake has rarely been studied. Here we studied the uptake and accumulation of Cd2+ ions in different parts of soybean plants of four cultivars Moravians, Gallec, Kent and Cardiff. The plants at early developmental stage were immersed in Hoagland nutrient solution in the presence or absence of 50 mg.L−1 and the isotope of 109Cd2+ to monitor its accumulation continuously at 24 h intervals for 10 days. Our results showed that the uptake rate varied among the cultivars, being the highest in roots of the cv. Moravians and the lowest in the cv. Gallec. We also observed a non-even distribution of radioactivity within the entire plants of individual cultivars. The most of Cd2+ isotope was translocated into primary leaves and leaves in the cvs. Kent and Moravians; on the contrary, relatively less in the cvs. Cardiff and Gallec. The results were fitted with genetic potential, growth as well as defense parameters such as proline accumulation. Combining uptake dynamics and biochemical data are indicative for different tolerance strategies of soybeans.