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Inorganic Chemistry Oct 2015With the aim of preparing hypoxia-selective imaging and therapeutic agents, technetium(I) and rhenium(I) tricarbonyl complexes with pyridylhydrazone, dipyridylamine, and...
With the aim of preparing hypoxia-selective imaging and therapeutic agents, technetium(I) and rhenium(I) tricarbonyl complexes with pyridylhydrazone, dipyridylamine, and pyridylaminocarboxylate ligands containing nitrobenzyl or nitroimidazole functional groups have been prepared. The rhenium tricarbonyl complexes were synthesized with short reaction times using microwave irradiation. Rhenium tricarbonyl complexes with deprotonated p-nitrophenyl pyridylhydrazone ligands are luminescent, and this has been used to track their uptake in HeLa cells using confocal fluorescent microscopy. Selected rhenium tricarbonyl complexes displayed higher uptake in hypoxic cells when compared to normoxic cells. A (99m)Tc tricarbonyl complex with a dipyridylamine ligand bearing a nitroimidazole functional group is stable in human serum and was shown to localize in a human renal cell carcinoma (RCC; SK-RC-52) tumor in a mouse.
Topics: Animals; Cell Line, Tumor; Diagnostic Imaging; Electrochemical Techniques; HeLa Cells; Humans; Hypoxia; Ligands; Luminescence; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Fluorescence; Models, Molecular; Molecular Structure; Organometallic Compounds; Rhenium; Technetium; Tissue Distribution
PubMed: 26375592
DOI: 10.1021/acs.inorgchem.5b01691 -
Bioorganic & Medicinal Chemistry Letters Apr 2021The transmetalation reaction between zinc dithiocarbamates functionalized with organic groups and the cation fac-[Tc(HO)(CO)] has been studied as a new strategy to bind...
The transmetalation reaction between zinc dithiocarbamates functionalized with organic groups and the cation fac-[Tc(HO)(CO)] has been studied as a new strategy to bind biomolecules to this radionuclide for preparing radiopharmaceuticals with high molar activity. All complexes were obtained in high yields by heating at moderate temperatures and without subsequent purification. The chemical identity was ascertained by HPLC comparison with the homologous rhenium complexes. Stability studies in cysteine solution and serum have shown a good stability of the coordination set fac-[Tc(CO)(SS)(P)]. Preliminary biological studies of the radiocomplex functionalized with D-(+)-glucosamine with carcinoma cells have been performed.
Topics: Animals; Coordination Complexes; Mice; Radiopharmaceuticals; Single Photon Emission Computed Tomography Computed Tomography; Technetium; Tissue Distribution; Zinc
PubMed: 33556570
DOI: 10.1016/j.bmcl.2021.127840 -
Journal of Aerosol Medicine and... Feb 2019Electronic cigarettes (ECIGs) are widely used, but their health effects are not well known. ECIG exposure is difficult to quantify, and a direct measurement of...
BACKGROUND
Electronic cigarettes (ECIGs) are widely used, but their health effects are not well known. ECIG exposure is difficult to quantify, and a direct measurement of deposition would be beneficial to in vivo and in vitro toxicity studies. The aim of this study was to demonstrate effective radiolabeling of an ECIG.
METHODS
A technetium-99m-labeled carbon ultrafine (TCU) aerosol was generated and introduced to a fourth-generation ECIG before nucleation and aerosol formation. The aerosolized e-liquid was a commercially available strawberry flavor containing 1.2% nicotine in a 55% propylene glycol and 45% vegetable glycerine base. An ECIG power setting of 100 W was selected. Mass and radioactivity were measured on each stage within a Sierra Cascade Impactor at 14 L/min to verify the labeling technique using the calculated aerodynamic diameters. A strong positive correlation (R > 0.95) between the percent activity and percent mass deposition on each stage provides a reliable validation of colocation.
RESULTS
Unlabeled ECIG aerosol from the chosen e-liquid produced a mass median aerodynamic diameter (MMAD) of 0.85 μm. An ECIG labeled with TCU produced an aerosol with an activity median aerodynamic diameter of 0.84 μm and an MMAD of 0.84 μm. The relative mass versus radioactivity on each plate was highly correlated (average R = 0.973, p < 0.001).
CONCLUSION
A TCU radiolabel was generated and shown to associate with the mass of an aerosol produced by a typical commercially available ECIG. Thus, the radioactivity of the deposited aerosol may be used to determine ECIG aerosol deposition for the future in vivo and in vitro dosimetry studies of the third- and fourth-generation ECIGs.
Topics: Administration, Inhalation; Aerosols; Carbon; Electronic Nicotine Delivery Systems; Nicotine; Nicotinic Agonists; Particle Size; Particulate Matter; Technetium; Vaping
PubMed: 30376396
DOI: 10.1089/jamp.2017.1442 -
Journal of Nuclear Medicine : Official... Apr 1972
Topics: Autoradiography; Chromatography, Paper; Colloids; Hydrogen Sulfide; Hydrogen-Ion Concentration; Hydrolysis; Isotope Labeling; Povidone; Radiochemistry; Rhenium; Sulfides; Technetium; Thiosulfates
PubMed: 5011784
DOI: No ID Found -
JACC. Cardiovascular Imaging Mar 2009Approximately 9 million nuclear cardiology studies performed each year in the U.S. use technetium-99m, which is produced from the decay of molybdenum-99. The fragility...
Approximately 9 million nuclear cardiology studies performed each year in the U.S. use technetium-99m, which is produced from the decay of molybdenum-99. The fragility of the worldwide technetium-99m supply chain has been underscored by current shortages caused by an unplanned shutdown of Europe's largest reactor. The majority of the U.S. supply derives from a reactor in Canada that is nearing the end of its lifespan and whose planned replacements have been cancelled recently. In this article, the clinical importance of technetium-99m and our tenuous dependence on the foreign supply of molybdenum are addressed, along with potential measures that may be taken to ensure that America's supply chain remains unbroken.
Topics: Canada; Commerce; Europe; Health Services Accessibility; Molybdenum; Private Sector; Public Sector; Radioisotopes; Radionuclide Generators; Radionuclide Imaging; Radiopharmaceuticals; Technetium; United States
PubMed: 19356583
DOI: 10.1016/j.jcmg.2008.10.008 -
Journal of Nuclear Medicine Technology Dec 2014
Topics: Canada; Erythrocytes; Isotope Labeling; Technetium
PubMed: 25472511
DOI: 10.2967/jnmt.114.148650 -
Cells May 2022Nuclear medicine staff are constantly exposed to low doses of ionizing radiation. This study investigated the level of genotoxic effects in hospital employees exposed to...
Nuclear medicine staff are constantly exposed to low doses of ionizing radiation. This study investigated the level of genotoxic effects in hospital employees exposed to routinely used I and Tc in comparison with a control group. The study compared the results of physical and biological monitoring in peripheral blood lymphocytes. The effects of confounding factors, such as smoking status and physical activity, were also considered. Physical dosimetry monitoring revealed differences in the individual annual effective dose as measured by finger ring dosimeter and whole-body dosimeter between the I- and Tc-exposed groups. The DNA damage studies revealed differences between the groups in terms of excess premature chromosome condensation (PCC) fragments and tail DNA. Physical activity and smoking status differentiated the investigated groups. When assessed by the level of physical activity, the highest mean values of tail DNA were observed for the Tc group. When assessed by work-related physical effort, excess PCC fragments were significantly higher in the I group than in the control group. In the investigated groups, the tail DNA values were significantly different between non-smokers and past or current smokers, but excess PCC fragments did not significantly differ by smoking status. It is important to measure exposure to low doses of ionizing radiation and assess the potential risk from this exposure. Such investigations support the need to continue epidemiological and experimental studies to improve our understanding of the mechanisms of the health effects of radionuclides and to develop predictive models of the behavior of these complex systems in response to low-dose radiation.
Topics: Biological Monitoring; DNA; DNA Damage; Humans; Iodine Radioisotopes; Nuclear Medicine; Occupational Exposure; Technetium
PubMed: 35626692
DOI: 10.3390/cells11101655 -
Journal of Nuclear Medicine : Official... Jun 2014
Topics: Cyclotrons; Radiochemistry; Technetium
PubMed: 24777289
DOI: 10.2967/jnumed.114.138008 -
Journal of Nuclear Medicine Technology Jun 2020The phenomenon of adsorption of several Tc-radiopharmaceuticals onto disposable syringes is common knowledge and can reach a level of up to 50%, with the result being...
The phenomenon of adsorption of several Tc-radiopharmaceuticals onto disposable syringes is common knowledge and can reach a level of up to 50%, with the result being inadequate dosing. The resulting underdosing has a substantial influence on the quality of imaging, especially in pediatric patients. Therefore, we aimed to establish a standardized in vitro assessment to investigate the adsorption of several Tc-radiopharmaceuticals on various brands of syringes. The Tc-radiopharmaceuticals were prepared according to manufacturer instructions. For the assessment, the disposable syringes ( = 3) were filled to one third of capacity with the Tc preparation and incubated for 30 min at room temperature. The syringes were emptied into evacuated vials, and the radioactivity of the syringes was measured before and after they were emptied. Furthermore, the dilution effect of Tc preparations was studied. We used 2 different brands of syringes and systematically examined Tc-pertechnetate, Tc-butedronate, Tc-oxidronate, Tc-medronate, Tc-tetrofosmin, Tc-sestamibi, Tc(V)-dimercaptosuccinic acid, and Tc-succimer. Additionally, Tc-succimer was retested with 5 brands of syringes. Tc-pertechnetate, Tc-phosphonates, and Tc(V)-dimercaptosuccinic acid showed no significant adsorption. The measured radioactive retention of 2%-5% was equivalent to the determined dead volume. Using Tc-tetrofosmin, we found a slight but significant adsorption of 4%-7%. The Tc-sestamibi preparation showed a nonsignificant retention of 3%-5%. However, when the Tc-sestamibi was diluted 1:10 with saline, the adsorption rate increased to 9%-13%. Tc-succimer displayed different adsorption levels depending on the brand of syringe and the preparation technique. The adsorption of Tc-succimer, prepared from kits according to the instructions, did not exceed 15%. The 1:10 saline dilution of a Tc-succimer kit preparation, as well as an in-house preparation, demonstrated a radioactive syringe adsorption rate of more than 30%. The results revealed the significance of syringe adsorption of radiopharmaceuticals in the prevention of underdosing. Therefore, a quality assurance assessment is recommended before the introduction of new brands of plastic syringes or routine application of diluted or in-house radiopharmaceuticals.
Topics: Adsorption; Artifacts; Plastics; Radiation Dosage; Radiopharmaceuticals; Syringes; Technetium
PubMed: 31811065
DOI: 10.2967/jnmt.119.235432 -
Scientific Reports Jul 2021Other than in animal models of human disease, little functional imaging has been performed in most of the animal world. The aim of this study was to explore the...
Other than in animal models of human disease, little functional imaging has been performed in most of the animal world. The aim of this study was to explore the functional anatomy of the European round back slug (Arionidae) and leopard slug (Limacidae) and to establish an imaging protocol for comparative species study. Radionuclide images with single photon emission computed tomography (SPECT) and positron emission tomography (PET) were obtained after injections of standard clinical radiopharmaceuticals technetium dicarboxypropane diphosphonate (bone scintigraphy), technetium mercaptoacetyltriglycine (kidney function), technetium diethylenetriaminepentaacetic acid (kidney function), technetium pertechnetate (mediated by the sodium-iodide symporter), technetium sestamibi (cardiac scintigraphy) or F-fluoro-deoxyglucose (glucose metabolism) in combination with magnetic resonance imaging (MRI) and computed tomography (CT) for uptake anatomic definition. Images were compared with anatomic drawings for the Arionidae species. Additionally, organ uptake data was determined for a description of slug functional anatomy in comparison to human tracer biodistribution patterns identifying the heart, the open circulatory anatomy, calcified shell remnant, renal structure (nephridium), liver (digestive gland) and intestine. The results show the detailed functional anatomy of Arionidae and Limacidae, and describe an in vivo whole-body imaging procedure for invertebrate species.
Topics: Animals; Gastropoda; Magnetic Resonance Spectroscopy; Radionuclide Imaging; Radiopharmaceuticals; Technetium; Tissue Distribution; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Whole Body Imaging
PubMed: 34226574
DOI: 10.1038/s41598-021-93012-2