The synthesis of tritium-labeled N,N-demethyl-2-phenylaziridinium has been described. The specific radioactivity of the product obtained was 1,06 TBq/mmole. Kinetics of incorporation of this radioactive label into acetylcholinesterase of cobra venom (Naja naja oxiana) has been studied at 1,05 mM ligand concentration (25 degrees C, pH 7,50. 0,15 M phosphate buffer). Under these conditions two molecules of the radioactive label have been found to react with the enzyme. One molecule incorporates fast with half-life of 4,8 min, not affecting the enzymatic activity. Incorporation of the second label is a slow reaction with half-life of 6 hr and leads to complete inactivation of acetylcholinesterase. Molecular mass of the modified enzyme is 63 +/- 4 kDa and coincides with that of native one.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Compartmental modeling for blood flow quantification from dynamic O-water PET images of humans: a systematic review.
Ann Nucl Med
January 2025
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Dynamic positron emission tomography (PET) can be used to non-invasively estimate the blood flow of different organs via compartmental modeling. Out of different PET tracers, water labeled with the radioactive O isotope of oxygen (half-life of 2.04 min) is freely diffusable, and therefore, very well-suited for blood flow quantification.
View Article and Find Full Text PDFRadiocaesium and radiostrontium transfer to an insect herbivore and an insect detritivore through holometabolous development: A comparison between the cabbage butterfly (Pieris brassicae) and the black soldier fly (Hermetia illucens).
Sci Total Environ
February 2025
Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway.
The presence of the long-lived radionuclides Cs and Sr in ecosystems is a major environmental concern because bioavailable forms of the radionuclides are readily transferred to living organisms. The present study investigated how holometabolous insect development influences the fate of radiocaesium and radiostrontium by examining the behaviour of tracers (Cs and Sr) and stable elements during the larval feeding stage (21-23 days old), the pupal stage, and the adult stage. We aimed to evaluate the degree to which an herbivore or a detritivore food chain could serve as transfer pathways to higher trophic levels in terms of accumulation potential, and during which stage of development the accumulation potential is highest.
View Article and Find Full Text PDFSingle-Injection Composite Tracer Achieves Intraoperative Dual-Tracing and Precise Localization of Sentinel Lymph Nodes.
ACS Appl Mater Interfaces
January 2025
Sixth People's Hospital, School of Medicine & School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, P. R. China.
The use of dual-tracer contrast agents in clinical applications, such as sentinel lymph node (SLN) identification, offers significant advantages including enhanced accuracy, sensitivity, as well as comprehensive and multimodal visualization. In the current clinical practice, SLNs are typically marked prior to surgical resection by multiple and sequential injections of two tracers, the radioactive tracer and methylene blue (MB) dye. This imposes physical and psychological burden on patients and medical staff.
View Article and Find Full Text PDFSentinel lymph node biopsy in breast cancer: the role of ICG fluorescence after neoadjuvant chemotherapy.
Breast Cancer Res Treat
January 2025
Department of Surgical Oncology, Medical University of Lublin, Radziwiłłowska 13 St., 20-080, Lublin, Poland.
Purpose: The purpose of this study was to evaluate the feasibility and safety of indocyanine green (ICG) fluorescence as an alternative to traditional sentinel lymph node biopsy (SLNB) techniques in breast cancer (BC) patients undergoing neoadjuvant chemotherapy (NAC). Specifically, the study aimed to assess sentinel node identification rates and the effectiveness of ICG in axillary staging without the use of radioactive tracers.
Methods: This retrospective study included 71 BC patients treated with NAC, who underwent SLNB using ICG fluorescence between 2020 and 2024.
Flow electrolytic separation of radionuclides for interference suppression in γ-spectrometry.
Anal Chim Acta
February 2025
Department of Chemistry and Applied Biosciences, Laboratory of Inorganic Chemistry, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, Zürich, CH-8093, Switzerland; Laboratory of Radiochemistry, Centre for Nuclear Engineering and Sciences, Paul Scherrer Institute, Forschungsstrasse 111, Villigen PSI, CH-5232, Switzerland. Electronic address:
Background: The direct and accurate measurement of low-level γ-emitters in samples from nuclear facilities is a challenging task due to the presence of high activities of dominant radionuclides. In this case a complex chemical separation is required to remove interfering radionuclides prior to γ-spectrometric analysis. Several radionuclides such as, Ag, Sb, Sn and Te are of relevance for radioanalytical analysis in nuclear facilities.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!