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- Eriksson, Olof, et al.
(författare)
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On the use of [F-18]DOPA as an imaging biomarker for transplanted islet mass
- 2014
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Ingår i: Annals of Nuclear Medicine. - : Springer Science and Business Media LLC. - 0914-7187 .- 1864-6433. ; 28:1, s. 47-52
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Tidskriftsartikel (refereegranskat)abstract
- AimIslet transplantation is being developed as a potential cure for patients with type 1 diabetes. There is a need for non-invasive imaging techniques for the quantification of transplanted islets, as current transplantation sites are associated with a substantial loss of islet viability. The dopaminergic metabolic pathway is present in the islets; therefore, we propose Fluorine-18 labeled l-3,4-dihydroxyphenylalanine ([F-18]DOPA) as a biomarker for transplanted islet mass.MethodsThe expression of enzymes involved in the dopaminergic metabolic pathway was investigated in both native and transplanted human islets. The specific uptake of [F-18]DOPA in islets and immortalized beta cells was studied in vitro by selective blocking of dopa decarboxylase (DDC). Initial in vivo PET imaging of viable subcutaneous human islets was performed using [F-18]DOPA.ResultsDDC and vesicular monoamine transporter 2 are co-localized with insulin in the native human pancreas, and the expression is retained after transplantation. Islet uptake of the [F-18]DOPA could be modulated by inhibiting DDC, indicating that the uptake followed the normal dopaminergic metabolic pathway. In vivo imaging revealed [F-18]DOPA uptake at the site of the functional islet graft. Based on the in vitro and in vivo results presented in this study, we propose to further validate [F-18]DOPA-PET as a sensitive imaging modality for imaging extrahepatically transplanted islets.
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| 2. |
- Neth, Bryan J, et al.
(författare)
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Modified ketogenic diet is associated with improved cerebrospinal fluid biomarker profile, cerebral perfusion, and cerebral ketone body uptake in older adults at risk for Alzheimer's disease: a pilot study.
- 2020
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Ingår i: Neurobiology of aging. - : Elsevier BV. - 1558-1497 .- 0197-4580. ; 86, s. 54-63
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Tidskriftsartikel (refereegranskat)abstract
- There is currently no established therapy to treat or prevent Alzheimer's disease. The ketogenic diet supplies an alternative cerebral metabolic fuel, with potential neuroprotective effects. Our goal was to compare the effects of a modified Mediterranean-ketogenic diet (MMKD) and an American Heart Association Diet (AHAD) on cerebrospinal fluid Alzheimer's biomarkers, neuroimaging measures, peripheral metabolism, and cognition in older adults at risk for Alzheimer's. Twenty participants with subjective memory complaints (n= 11) or mild cognitive impairment (n= 9) completed both diets, with 3 participants discontinuing early. Mean compliance rates were 90% for MMKD and 95% for AHAD. All participants had improved metabolic indices following MMKD. MMKD was associated with increased cerebrospinal fluid Aβ42 and decreased tau. There was increased cerebral perfusion and increased cerebral ketone body uptake (11C-acetoacetate PET, in subsample) following MMKD. Memory performance improved after both diets, which may be due to practice effects. Our results suggest that a ketogenic intervention targeted toward adults at risk for Alzheimer's may prove beneficial in the prevention of cognitive decline.
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