Following the in vivo biodistribution of platelets can contribute to a better understanding of their physiological and pathological roles, and nuclear imaging methods, such as single photon emission ...tomography (SPECT), provide an excellent method for that. SPECT imaging needs stable labeling of the platelets with a radioisotope. In this study, we report a new method to label platelets with sup.99mTc, the most frequently used isotope for SPECT in clinical applications. The proposed radiolabeling procedure uses a membrane-binding peptide, duramycin. Our results show that duramycin does not cause significant platelet activation, and radiolabeling can be carried out with a procedure utilizing a simple labeling step followed by a size-exclusion chromatography-based purification step. The in vivo application of the radiolabeled human platelets in mice yielded quantitative biodistribution images of the spleen and liver and no accumulation in the lungs. The performed small-animal SPECT/CT in vivo imaging investigations revealed good in vivo stability of the labeling, which paves the way for further applications of sup.99mTc-labeled-Duramycin in platelet imaging.
iRENEX is a software module that incorporates scintigraphic and clinical data to interpret 99m Tc- mercaptoacetyltriglycine (MAG3) diuretic studies and provide reasons for their conclusions. Our ...objectives were to compare iRENEX interpretations with those of expert physicians, use iRENEX to evaluate resident performance and determine if iRENEX could improve the diagnostic accuracy of experienced residents.
Baseline and furosemide 99m Tc-MAG3 acquisitions of 50 patients with suspected obstruction (mean age ± SD, 58.7 ± 15.8 years, 60% female) were randomly selected from an archived database and independently interpreted by iRENEX, three expert readers and four nuclear medicine residents with one full year of residency. All raters had access to scintigraphic data and a text file containing clinical information and scored each kidney on a scale from +1.0 to -1.0. Scores ≥0.20 represented obstruction with higher scores indicating greater confidence. Scores +0.19 to -0.19 were indeterminate; scores ≤-0.20 indicated no obstruction. Several months later, residents reinterpreted the studies with access to iRENEX. Receiver operating characteristic (ROC) analysis and concordance correlation coefficient (CCC) quantified agreement.
The CCC among experts was higher than that among residents, 0.84, versus 0.39, respectively, P < 0.001. When residents reinterpreted the studies with iRENEX, their CCC improved from 0.39 to 0.73, P < 0.001. ROC analysis showed significant improvement in the ability of residents to distinguish between obstructed and non-obstructed kidneys using iRENEX ( P = 0.036).
iRENEX interpretations were comparable to those of experts. iRENEX reduced interobserver variability among experienced residents and led to better agreement between resident and expert interpretations.
Novel imaging tools, including multiparametric magnetic resonance imaging and molecular imaging techniques, are capable of noninvasively characterizing indeterminate renal masses. Pending validation ...and increased adoption, these tools can be combined with radiomics and artificial intelligence to provide a comprehensive virtual biopsy, ultimately allowing for risk-adapted tailored treatment approaches for patients.
The incidental detection of localized renal masses has been rising steadily, but a significant proportion of these tumors are benign or indolent and, in most cases, do not require treatment. At the present time, a majority of patients with an incidentally detected renal tumor undergo treatment for the presumption of cancer, leading to a significant number of unnecessary surgical interventions that can result in complications including loss of renal function. Thus, there exists a clinical need for improved tools to aid in the pretreatment characterization of renal tumors to inform patient management.
To systematically review the evidence on noninvasive, imaging-based tools for solid renal mass characterization.
The MEDLINE database was systematically searched for relevant studies on novel imaging techniques and interpretative tools for the characterization of solid renal masses, published in the past 10 yr.
Over the past decade, several novel imaging tools have offered promise for the improved characterization of indeterminate renal masses. Technologies of particular note include multiparametric magnetic resonance imaging of the kidney, molecular imaging with targeted radiopharmaceutical agents, and use of radiomics as well as artificial intelligence to enhance the interpretation of imaging studies. Among these, 99mTc-sestamibi single photon emission computed tomography/computed tomography (CT) for the identification of benign renal oncocytomas and hybrid oncocytic chromophobe tumors, and positron emission tomography/CT imaging with radiolabeled girentuximab for the identification of clear cell renal cell carcinoma, are likely to be closest to implementation in clinical practice.
A number of novel imaging tools stand poised to aid in the noninvasive characterization of indeterminate renal masses. In the future, these tools may aid in patient management by providing a comprehensive virtual biopsy, complete with information on tumor histology, underlying molecular abnormalities, and ultimately disease prognosis.
Not all renal tumors require treatment, as a significant proportion are either benign or have limited metastatic potential. Several innovative imaging tools have shown promise for their ability to improve the characterization of renal tumors and provide guidance in terms of patient management.
The development of new drugs that can specifically screen tumors is a global need. When it comes to lung cancer, which is the second main cause of cancer-related deaths, early detection of lung ...tumors using appropriate imaging is very important. In this study, gemcitabine hydrochloride (GCH) was radiolabeled with 99mTcTc under different conditions (changing reducing agent, antioxidant agent, incubation time, pH, 99mTcTc activity) and radiolabeling activity (quality control) using Radio Thin Layer Chromatography and paper electrophoresis. The results showed that the most stable complex (99mTcTc-GCH) was prepared using 0.015 mg of stannous chloride as a reducing agent, 0.01 mg of ascorbic acid as an antioxidant and 37 MBq activity at pH 7.4 after 15 min of incubation time. The complex remained stable for 6 h. Cell incorporation studies showed a six-fold higher uptake of 99mTcTc-GCH in cancer (A-549) cells (38.42 ± 1.53) than healthy (L-929) cells (6.11 ± 0.17) have shown that it can. In addition, the different behaviors of R/H-99mTcTc confirmed the specificity of this newly developed radiopharmaceutical. Although these studies are preliminary, it has been concluded that 99mTcTc-GCH may be a candidate drug for use in nuclear medicine, particularly in the diagnosis of lung cancer.
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•99mTcTc-gemcitabine hydrochloride (GCH) was produced.•Varying reducing agent, antioxidant agent, incubation time, pH, and activity of 99mTcTc was optimized.•Quality control studies: Radio Thin Layer Chromatography and paper electrophoresis.•99mTcTc-GCH was able to bind the cancer cells higher than healthy cells corroborating the specificity of the GCH.
•REBa2Cu3O7-δ superconducting phases having a high-entropy-alloy-type RE site have been synthesized.•A transition temperature is not affected by the presence of the high-entropy-alloy-type RE ...site.•For all the REBa2Cu3O7-δ samples examined in this work, a transition temperature and a critical current density tended to increase with increasing orthorhombicity.
We have synthesized high-entropy-alloy-type (HEA-type) RE123 superconductors Y0.28Nd0.16Sm0.18Eu0.18Gd0.20Ba2Cu3O7-δ and Y0.18La0.24Nd0.14Sm0.14Eu0.15Gd0.15Ba2Cu3O7-δ with a superconducting transition temperature (Tc) exceeding 90 K. From comparison between HEA-type and conventional RE123 samples, we found that the mixing entropy at the rare earth site does not affect Tc and critical current density (Jc) of the RE123 samples. For all the examined samples, orthorhombicity was found to be an essential parameter for Tc and Jc.
The well designed TCPP/GQDs/Bi2MoO6 Z-scheme heterojunction can be utilized as a highly efficient and stable photocatalyst for pharmaceutical antibiotic degradation and Cr(VI) reduction under visible ...light.
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Constructing novel Z-scheme heterojunctions is an effective strategy for obtaining high-performance photocatalysts. Herein, tetra (4-carboxyphenyl) porphyrin (TCPP) and graphene quantum dots (GQDs) were loaded on the surface of Bi2MoO6 (BMO) to fabricate novel Z-scheme heterojunctions of TCPP/G/BMO. Especially, TCPP/G/BMO-2 showed an exceptional visible-light photoactivity for tetracycline (TC) degradation (81.0%, 40 min) and Cr(VI) reduction (90.7%, 60 min), respectively by 2.38 folds and 2.96 folds enhancement compared to sole Bi2MoO6. The substantial enhancement of activity is attributed to the synergy effect of the Z-scheme charge transfer mechanism and the improved light absorption. The degradation pathways of TC were inferred by determining the generated intermediates using high performance liquid chromatography-mass spectrometry (HPLC-MS), and the toxicity of the transformation products was assessed by Toxicity Estimation Software Tool (T.E.S.T). Overall, on the basis of trapping experiments and electron spin resonance spectra (ESR) analysis, the photocatalytic mechanisms of Cr(VI) reduction and TC degradation by the TCPP/G/BMO Z-scheme heterojunction was proposed. This work indicates TCPP/G/BMO could be a promising photocatalyst for wastewater treatment.
•Historical discoveries of hole-doped cuprates and representative milestone work.•Several simple and universal scaling laws of the hole-doped cuprates.•A comprehensive classification list with ...references for hole-doped cuprates.•Representative physical parameters for selected hole-doped cuprates.
Hole-doped cuprate high temperature superconductors have ushered in the modern era of high temperature superconductivity (HTS) and have continued to be at center stage in the field. Extensive studies have been made, many compounds discovered, voluminous data compiled, numerous models proposed, many review articles written, and various prototype devices made and tested with better performance than their nonsuperconducting counterparts. The field is indeed vast. We have therefore decided to focus on the major cuprate materials systems that have laid the foundation of HTS science and technology and present several simple scaling laws that show the systematic and universal simplicity amid the complexity of these material systems, while referring readers interested in the HTS physics and devices to the review articles. Developments in the field are mostly presented in chronological order, sometimes with anecdotes, in an attempt to share some of the moments of excitement and despair in the history of HTS with readers, especially the younger ones.
In addition to gamma radiation,
Tc emits low-energy Auger electrons with path-lengths of nanometers to micrometers that cannot be utilized for diagnostic procedures; however, they have frequently ...been discussed for therapeutic applications. We compared radiotoxicity of three
Tc-labeled radiopharmaceuticals with differences in the subcellular distribution.
The intracellular radionuclide uptake and subcellular distribution of
Tc-pertechnetate (
Tc-pertechnetate),
TcTc-hexamethyl-propylene-aminoxime (
Tc-HMPAO) and
TcTc-hexakis-2-methoxyisobutylisonitrile (
Tc-MIBI) were quantified in rat thyroid FRTL-5 cells. Radiotoxicity was compared using late phosphorylated histone H2AX (γH2AX) foci as a marker for unrepaired DNA double-strand breaks (DNA-DSB) and clonogenic cell survival.
Tc-HMPAO showed a substantially higher uptake into the nucleus and the membrane/organelles than
Tc-pertechnetate or
Tc-MIBI. The colony-forming assay showed that
Tc-pertechnetate and
Tc-HMPAO caused a similar reduction in cell survival.
Tc-MIBI is less radiotoxic in terms of the estimated nucleus dose and induced the fewest number of γH2AX foci compared with the other
Tc-tracers, and
Tc-HMPAO induced a fewer number of γH2AX foci than
Tc-pertechnetate.
Our findings reveal that clonogenic cellular survival is not solely determined by the DNA-DSB response. This finding may suggest the involvement of extra-nuclear radiosensitive targets in cell inactivation. For example, the mitochondria or the cell membrane could be affected by
Tc-HMPAO.
•Three new supramolecular materials with novel structures were prepared•The three materials were tested and analyzed by FT-IR, EA, PXRD, TG-DTA, BG•The photocatalytic degradation performance and ...kinetics for tetracycline were studied.•The H2O2/compound 1 system has good catalytic degradation ability for tetracycline.
As a class of materials with novel structures and good functionality, supramolecular compounds are frequently used for photocatalytic degradation of organic pollutants. On this basis, three new supramolecular materials {L1·Ag5I8}n (1), {(L2)·(Ag5I8)·DMF}n (2) and {L3·Ag6I9}n (3) were synthesized by solution volatilization reaction of three cationic templates 1,3,5-Tris(diethylaminomethyl)-2,4,6-Trimethylphenyl bromide (L1), 1,3,5-Tris(trimethylaminomethyl)-phenyl bromide (L2) and 1,3,5-Tris(1-methylimidazolylmethyl)-2,4,6-trimethylphenyl bromide (L3) with AgI at room temperature, respectively. Compounds 1-3 were characterized by elemental analysis, infrared spectroscopy, UV-vis absorption spectroscopy, and thermometry. The results of single crystal X-ray diffraction analysis show that compounds 1-3 are anion polymers with multinuclear building blocks. As a catalyst, compound 1/H2O2 has a good degradation effect on tetracycline (TC) under visible light irradiation. The adsorption dynamics are best fit by quasi-first order models.
The design and synthesis of catalysts with high-intensity photocatalytic properties has been the focus of many researchers in recent years. On this basis, three new 1-3D supramolecular materials {L1·Ag5I8}n (1), {(L2)·(Ag5I8)·DMF}n (2) and {L3·Ag6I9}n (3) were synthesized by solution volatilization reaction of three cationic templates 1,3,5-Tris(diethylaminomethyl)-2,4,6-Trimethylphenyl bromide (L1), 1,3,5-Tris(trimethylaminomethyl)-phenyl bromide (L2) and 1,3,5-Tris(1-methylimidazolylmethyl)-2,4,6-trimethylphenyl bromide (L3) with AgI at room temperature, respectively. Compounds 1-3 were characterized by elemental analysis, infrared spectroscopy, UV-vis absorption spectroscopy, and thermometry. The results of single crystal X-ray diffraction analysis show that compounds 1-3 are anion polymers with multinuclear building blocks. As a catalyst, compound 1/H2O2 has a good degradation effect on tetracycline (TC) under visible light irradiation. The adsorption dynamics are best fit by quasi-first order models. Display omitted
Cyclotron production of 99mTc is a promising route to supply 99mTc radiopharmaceuticals. Higher 99mTc yields can be obtained with medium-energy cyclotrons in comparison to those dedicated to PET ...isotope production. To take advantage of this capability, evaluation of the radioisotopic purity of 99mTc produced at medium energy (20-24 MeV) and its impact on image quality and dosimetry was required.
Thick 100Mo (99.03% and 99.815%) targets were irradiated with incident energies of 20, 22, and 24 MeV for 2 or 6 h. The targets were processed to recover an effective thickness corresponding to approximately 5-MeV energy loss, and the resulting sodium pertechnetate 99mTc was assayed for chemical, radiochemical, and radionuclidic purity. Radioisotopic content in final formulation was quantified using γ-ray spectrometry. The internal radiation dose for 99mTc-pertechnetate was calculated on the basis of experimentally measured values and biokinetic data in humans. Planar and SPECT imaging were performed using thin capillary and water-filled Jaszczak phantoms.
Extracted sodium pertechnetate 99mTc met all provisional quality standards. The formulated solution for injection had a pH of 5.0-5.5, contained greater than 98% of radioactivity in the form of pertechnetate ion, and was stable for at least 24 h after formulation. Radioisotopic purity of 99mTc produced with 99.03% enriched 100Mo was greater than 99.0% decay corrected to the end of bombardment (EOB). The radioisotopic purity of 99mTc produced with 99.815% enriched 100Mo was 99.98% or greater (decay corrected to the EOB). The estimated dose increase relative to 99mTc without any radionuclidic impurities was below 10% for sodium pertechnetate 99mTc produced from 99.03% 100Mo if injected up to 6 h after the EOB. For 99.815% 100Mo, the increase in effective dose was less than 2% at 6 h after the EOB and less than 4% at 15 h after the EOB when the target was irradiated at an incident energy of 24 MeV. Image spatial resolution and contrast with cyclotron-produced 99mTc were equivalent to those obtained with 99mTc eluted from a conventional generator.
Clinical-grade sodium pertechnetate 99mTc was produced with a cyclotron at medium energies. Quality control procedures and release specifications were drafted as part of a clinical trial application that received approval from Health Canada. The results of this work are intended to contribute to establishing a regulatory framework for using cyclotron-produced 99mTc in routine clinical practice.
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