68Ge/68Ga generators provide cyclotron-independent access to positron emission tomography (PET) radiopharmaceuticals. We describe a system which allows the safe and efficient handling of 68Ge/68Ga generator eluates for labelling of DOTA-derivatised peptide ligands. The system comprises concentration and purification of the 68Ga eluate as well as labelling and purification steps for peptides, and can be used with different 68Ge/68Ga generator types. The suitability and efficiency were tested with two different DOTA-derivatised somatostatin derivatives and a DOTA-derivatised bombesin derivative. Amounts of 10-20 nmol of the peptides were sufficient and resulted in labelling yields of 50% for all peptides. The built-in safety precautions have proven to be appropriate in allowing use of the method for routine clinical applications. The system was set up and operated in a "hot lab" by personnel with no previous experience in the preparation of PET radiopharmaceuticals.
Background. Insulin resistance and glucose intolerance are a major feature of patients with liver cirrhosis. However, site and mechanism of insulin resistance in cirrhosis are unknown. We investigated insulin-induced glucose metabolism of skeletal muscle by positron-emission tomography to identify possible defects of muscle glucose metabolism in these patients.Methods. Whole body glucose disposal and oxidation were determined by the combined use of the euglycemic-hyperinsulinemic clamp technique (insulin infusion rate: 1 mU/kg body wt per min) and indirect calorimetry in seven patients with biopsy-proven liver cirrhosis (Child: 1A, 5B, and 1C) and five
This study investigates the incorporation of bone grafts used in maxillofacial surgery by means of [18F]fluoride ion and positron emission tomography (PET). It considers patients who received pedicle grafts for mandibular reconstruction or onlay grafts for alveolar ridge augmentation. Dynamic PET images and arterialized venous blood samples were obtained within a 1-h period after i.v. injection of [18F]fluoride. Assuming a three-compartment model and applying multilinear least squares fitting, bone blood flow (K1) and fluoride influx (Kmlf) were determined. Additionally Patlak plot analysis was used to calculate fluoride influx (Kpat). In cervical vertebral bodies as the reference region, mean values for flow of K1 = 0.1162 +/- 0.0396 ml/min/ml and influx of Kmlf = 0.0508 +/- 0.0193 and Kpat = 0.0385 +/- 0.0102 ml/min/ml were found. Essentially these figures are comparable with physiological values in animal and man reported in the literature. Early after surgery a significant increase in flow and influx compared to vertebral bodies was observed in the regions of osteosyntheses between grafts used for reconstruction and recipient bone (K1 = 0.2181, Kmlf = 0.1000 and Kpat = 0.0666 ml/min/ml) and in onlay grafts (K1 = 0.2842, Kmlf = 0.1637 and Kpat = 0.0827 ml/min/ml). At the same time pedicle grafts showed a significant increase in flow but not in influx (K1 = 0.2042, Kmlf = 0.0774 and Kpat = 0.0529 ml/min/ml). Furthermore Kpat was significantly lower in pedicle grafts than in onlay grafts. In follow-up studies a significant decrease in flow occurred in pedicle grafts and the regions of osteosyntheses. Moreover the latter showed a significant decrease in Kmlf as well. It is concluded that [18F(-)] PET depicted increased blood flow and osteoblastic activity in onlay grafts and regions of osteosyntheses, indicating bone repair in the graft and adjacent host bone early after surgery. For the regions of osteosyntheses the decrease in both parameters corresponded to uncomplicated healing. The lack of increased influx, although flow was increased in pedicle grafts, most likely indicates that some necrosis occurred in these grafts despite patency of anastomoses. It may be concluded that [18F(-)] PET provides further insight into the biology of graft incorporation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.