Anorexia nervosa is associated with higher brain mu-opioid receptor availability.

Anorexia nervosa (AN) is a severe psychiatric disorder, characterized by restricted eating, fear to gain weight, and a distorted body image. Mu-opioid receptor (MOR) functions as a part of complex opioid system and supports both homeostatic and hedonic control of eating behavior. Thirteen patients with AN and thirteen healthy controls (HC) were included in this study.

P2X -receptor binding in new-onset and secondary progressive MS - a [C]SMW139 PET study.

Background: PET imaging of activated microglia has improved our understanding of the pathology behind disability progression in MS, and pro-inflammatory microglia at 'smoldering' lesion rims have been implicated as drivers of disability progression. The P2X R is upregulated in the cellular membranes of activated microglia. A single-tissue dual-input model was applied to quantify P2X R binding in the normal appearing white matter, perilesional areas and thalamus among progressive MS patients, healthy controls and newly diagnosed relapsing MS patients.

Aberrant type 2 dopamine receptor availability in violent offenders with psychopathy.

Psychopathy is characterized by antisocial behavior, poor behavioral control and lacking empathy, and structural alterations in the corresponding neural circuits. Molecular brain basis of psychopathy remains poorly characterized. Here we studied type 2 dopamine receptor (D2R) and mu-opioid receptor (MOR) availability in convicted violent offenders with high psychopathic traits (n = 11) and healthy matched controls (n = 17) using positron emission tomography (PET).

Blood biomarkers of neurodegeneration associate differently with amyloid deposition, medial temporal atrophy, and cerebrovascular changes in APOE ε4-enriched cognitively unimpaired elderly.

Background: Alzheimer's disease (AD) is characterized by the accumulation of amyloid-β (Aβ) plaques, neurofibrillary tau tangles, and neurodegeneration in the brain parenchyma. Here, we aimed to (i) assess differences in blood and imaging biomarkers used to evaluate neurodegeneration among cognitively unimpaired APOE ε4 homozygotes, heterozygotes, and non-carriers with varying risk for sporadic AD, and (ii) to determine how different cerebral pathologies (i.e.

In-target production of [C]CH from a nitrogen/hydrogen gas target as a function of beam current, irradiation time, and target temperature.

Background: Production of [C]CH from gas targets is notorious for weak performance with respect to yield, especially when using high beam currents. Post-target conversion of [C]CO to [C]CH is a widely used roundabout method in C-radiochemistry, but the added complexity increase the challenge to control carrier carbon. Thus in-target-produced [C]CH is superior with respect to molar activity.

Cognitively healthy APOE4/4 carriers show white matter impairment associated with serum NfL and amyloid-PET.

Except for aging, carrying the APOE ε4 allele (APOE4) is the most important risk factor for sporadic Alzheimer's disease. APOE4 carriers may have reduced capacity to recycle lipids, resulting in white matter microstructural abnormalities. In this study, we evaluated whether white matter impairment measured by diffusion tensor imaging (DTI) differs between healthy individuals with a different number of APOE4 alleles, and whether white matter impairment associates with brain beta-amyloid (Aβ) load and serum levels of neurofilament light chain (NfL).

Midlife insulin resistance, APOE genotype, and change in late-life brain beta-amyloid accumulation - A 5-year follow-up [C]PIB-PET study.

We studied if midlife insulin resistance (IR) and APOE genotype would predict brain beta-amyloid (Aβ) accumulation and Aβ change in late-life in 5-year follow-up [C]PIB-PET study. 43 dementia-free participants were scanned twice with [C]PIB-PET in their late-life (mean age at follow-up 75.4 years).

Head-to-head comparison of plasma p-tau181, p-tau231 and glial fibrillary acidic protein in clinically unimpaired elderly with three levels of APOE4-related risk for Alzheimer's disease.

Plasma phosphorylated tau (p-tau) and glial fibrillary acidic protein (GFAP) both reflect early changes in Alzheimer's disease (AD) pathology. Here, we compared the biomarker levels and their association with regional β-amyloid (Aβ) pathology and cognitive performance head-to-head in clinically unimpaired elderly (n = 88) at three levels of APOE4-related genetic risk for sporadic AD (APOE4/4 n = 19, APOE3/4 n = 32 or non-carriers n = 37). Concentrations of plasma p-tau181, p-tau231 and GFAP were measured using Single molecule array (Simoa), regional Aβ deposition with C-PiB positron emission tomography (PET), and cognitive performance with a preclinical composite.

Insulin resistance and body mass index are associated with TSPO PET in cognitively unimpaired elderly.

Metabolic risk factors are associated with peripheral low-grade inflammation and an increased risk for dementia. We evaluated if metabolic risk factors i.e.

APOE ε4 gene dose effect on imaging and blood biomarkers of neuroinflammation and beta-amyloid in cognitively unimpaired elderly.

Background: Neuroinflammation, characterized by increased reactivity of microglia and astrocytes in the brain, is known to be present at various stages of the Alzheimer's disease (AD) continuum. However, its presence and relationship with amyloid pathology in cognitively normal at-risk individuals is less clear. Here, we used positron emission tomography (PET) and blood biomarker measurements to examine differences in neuroinflammation and beta-amyloid (Aβ) and their association in cognitively unimpaired homozygotes, heterozygotes, or non-carriers of the APOE ε4 allele, the strongest genetic risk for sporadic AD.

[C]carfentanil PET imaging for studying the peripheral opioid system in vivo: effect of photoperiod on mu-opioid receptor availability in brown adipose tissue.

Purpose: Photoperiod determines the metabolic activity of brown adipose tissue (BAT) and affects the food intake and body mass of mammals. Sympathetic innervation of the BAT controls thermogenesis and facilitates physiological adaption to seasonal changes, but the exact mechanism remains elusive. Previous studies have shown that central opioid signaling regulates BAT thermogenesis, and that the expression of the brain mu-opioid receptor (MOR) varies seasonally.

Adenosine A receptor availability in patients with early- and moderate-stage Parkinson's disease.

Introduction: Adenosine 2A (A) receptors co-localize with dopamine Dreceptors in striatopallidal medium spiny neurons of the indirect pathway. A receptor activation in the striatum or pallidum decreases Dsignaling. In contrast, A receptor antagonism may help potentiate it.

Obesity risk is associated with altered cerebral glucose metabolism and decreased μ-opioid and CB receptor availability.

Background: Obesity is a pressing public health concern worldwide. Novel pharmacological means are urgently needed to combat the increase of obesity and accompanying type 2 diabetes (T2D). Although fully established obesity is associated with neuromolecular alterations and insulin resistance in the brain, potential obesity-promoting mechanisms in the central nervous system have remained elusive.

Comparison of: (2,4)-4-[F]Fluoroglutamine, [C]Methionine, and 2-Deoxy-2-[F]Fluoro--Glucose and Two Small-Animal PET/CT Systems Imaging Rat Gliomas.

Purpose: The three positron emission tomography (PET) imaging compounds: (2,4)-4-[F]Fluoroglutamine ([F]FGln), -[methyl-C]Methionine ([C]Met), and 2-deoxy-2-[F]fluoro--glucose ([F]FDG) were investigated to contrast their ability to image orthotopic BT4C gliomas in BDIX rats. Two separate small animal imaging systems were compared for their tumor detection potential. Dynamic acquisition of [F]FGln was evaluated with multiple pharmacokinetic models for future quantitative comparison.

Episodic memory and cortical amyloid pathology: PET study in cognitively discordant twin pairs.

We studied the association between episodic memory and cortical fibrillar β-amyloid pathology within twin pairs. Using telephone-administered cognitive screening of 1415 twin pairs in a population-based older Finnish Twin Cohort study, we identified 45 (mean [SD] age 72.9 [4.

Direct Comparison of [F]F-DPA with [F]DPA-714 and [C]PBR28 for Neuroinflammation Imaging in the same Alzheimer's Disease Model Mice and Healthy Controls.

Purpose: In this study we compared the recently developed TSPO tracer [F]F-DPA, with [F]DPA-714 and [C]PBR28 by performing in vivo PET imaging on the same Alzheimer's disease mouse model APP/PS1-21 (TG) and wild-type (WT) mice with all three radiotracers.

Procedures: To compare the radiotracer uptake, percentage of injected dose/mL (%ID/mL), standardized uptake value ratios to cerebellum (SUVR), and voxel-wise analyses were performed.

Results: The peak uptake of [F]F-DPA was higher than 4.

Mesolimbic opioid-dopamine interaction is disrupted in obesity but recovered by weight loss following bariatric surgery.

Obesity is a growing burden to health and the economy worldwide. Obesity is associated with central µ-opioid receptor (MOR) downregulation and disruption of the interaction between MOR and dopamine D receptor (DR) system in the ventral striatum. Weight loss recovers MOR function, but it remains unknown whether it also recovers aberrant opioid-dopamine interaction.

Preoperative brain μ-opioid receptor availability predicts weight development following bariatric surgery in women.

Bariatric surgery is the most effective method for weight loss in morbid obesity. There is significant individual variability in the weight loss outcomes, yet factors leading to postoperative weight loss or weight regain remain elusive. Alterations in the μ-opioid receptor (MOR) and dopamine D2 receptor (D2R) systems are associated with obesity and appetite control, and the magnitude of initial brain receptor system perturbation may predict long-term surgical weight loss outcomes.

Effect of dopaminergic medication on adenosine 2A receptor availability in patients with Parkinson's disease.

Objective: To assess the necessity of withdrawing dopaminergic medication in Parkinson's disease (PD) patients for accurate estimation of adenosine 2A receptor (AR) availability using [C]TMSX PET imaging. This was accomplished by studying the short-term effect of the cessation of dopaminergic medication on AR availability in non-dyskinetic patients with PD treated with dopaminergic medication.

Methods: Eight PD patients (age 67.

Association of Early β-Amyloid Accumulation and Neuroinflammation Measured With [C]PBR28 in Elderly Individuals Without Dementia.

Objective: To examine whether early β-amyloid (Aβ) accumulation and metabolic risk factors are associated with neuroinflammation in elderly individuals without dementia.

Methods: We examined 54 volunteers (mean age 70.0 years, 56% women, 51% ɛ4 carriers) with the translocator protein (TSPO) tracer [C]PBR28 to assess neuroinflammation and with [C] Pittsburgh compound B (PiB) to assess cerebral Aβ accumulation.

Seasonal Variation in the Brain μ-Opioid Receptor Availability.

Seasonal rhythms influence mood and sociability. The brain μ-opioid receptor (MOR) system modulates a multitude of seasonally varying socioemotional functions, but its seasonal variation remains elusive with no previously reported evidence. Here, we first conducted a cross-sectional study with previously acquired human [C]carfentanil PET imaging data (132 male and 72 female healthy subjects) to test whether there is seasonal variation in MOR availability.

Functional imaging with 11C-metomidate PET for subtype diagnosis in primary aldosteronism.

Objective: Endocrine Society guidelines recommend adrenal venous sampling (AVS) in primary aldosteronism (PA) if adrenalectomy is considered. We tested whether functional imaging of adrenal cortex with 11C-metomidate (11C-MTO) could offer a noninvasive alternative to AVS in the subtype classification of PA.

Design: We prospectively recruited 58 patients with confirmed PA who were eligible for adrenal surgery.

Association of neuroinflammation with episodic memory: a [C]PBR28 PET study in cognitively discordant twin pairs.

Alzheimer's disease is associated with chronic response of innate immune system, referred as neuroinflammation. PET radioligands binding to the 18 kDa translocator protein are potential biomarkers of neuroinflammation. Translocator protein PET studies in mild cognitive impairment and Alzheimer's disease have indicated controversial results, possibly reflecting interindividual variation and heterogeneity of study populations.