If It Works, Don't Touch It? A Cell-Based Approach to Studying 2-[F]FDG Metabolism.

The glucose derivative 2-[F]fluoro-2-deoxy-D-glucose (2-[F]FDG) is still the most used radiotracer for positron emission tomography, as it visualizes glucose utilization and energy demand. In general, 2-[F]FDG is said to be trapped intracellularly as 2-[F]FDG-6-phosphate, which cannot be further metabolized. However, increasingly, this dogma is being questioned because of publications showing metabolism beyond 2-[F]FDG-6-phosphate and even postulating 2-[F]FDG imaging to depend on the enzyme hexose-6-phosphate dehydrogenase in the endoplasmic reticulum.

Disrupted relationship between blood glucose and brain dopamine D2/3 receptor binding in patients with first-episode schizophrenia.

An elemental function of brain dopamine is to coordinate cognitive and motor resources for successful exploitation of environmental energy sources. Dopamine transmission, goal-directed behavior, and glucose homeostasis are altered in schizophrenia patients prior to and after initiation of pharmacological treatment. Thus, we investigated the relationship between blood glucose levels and brain dopamine signaling in drug-naïve patients with first-episode psychosis.

Feasibility of In Vivo Imaging of Fibroblast Activation Protein in Human Arterial Walls.

Increased expression of fibroblast-activating protein (FAP) in fibrous caps may contribute to progression of atherosclerotic plaques. Forty-one patients who underwent Ga-conjugated quinoline-based FAP inhibitor (Ga-FAPI-04) PET/CT for noncardiovascular indications were retrospectively analyzed. Correlations were assessed between the uptake of Ga-FAPI-04 in large arterial walls (SUV and target-to-background ratio, TBR) and degree of calcification and cardiovascular risk factors.

CXCR4 PET/MRI for follow-up of gastric mucosa-associated lymphoid tissue lymphoma after first-line Helicobacter pylori eradication.

Posttreatment evaluation of gastric mucosa-associated lymphoid tissue (MALT) lymphoma currently relies on esophagogastroduodenoscopy with histological assessment of biopsies. Overexpression of the G protein-coupled C-X-C chemokine receptor type 4 (CXCR4) has been previously observed in MALT lymphoma. The aim of this prospective study was to evaluate positron emission tomography (PET) with the novel CXCR4 tracer [68Ga]Pentixafor as a potential alternative to follow up biopsies for assessment of residual disease (noncomplete remission [CR]) after first-line Helicobacter pylori eradication.

[68Ga]DOTA-TATE PET for the detection of early transplant rejection in a heterotopic allograft heart transplantation model of the rat: a pilot study.

Background: The most important cause of heart transplant loss is early acute allograft rejection, caused by the infiltration of lymphocytes, development of edema and myocardial necrosis. It has been propagated that [68Ga]DOTA-TATE PET might be suitable to quantify the presence of SSTR over-expressing lymphocytes. With heterotopic allogenic heart transplant models in the rat readily available, we aimed to investigate, if monitoring and quantification of acute allograft rejection after heterotopic allogenic heart transplantation was feasible by non-invasive serial [68Ga]DOTA-TATE PET.

Combining body mass index with waist circumference to assess coronary microvascular function in patients with non-obstructive coronary artery disease.

Background: Coronary microvascular dysfunction (CMD) may precede clinically overt coronary artery disease (CAD). Overall and central obesity (CO) are major risk factors for CAD. This study sought to investigate the subclinical significance of body adiposity patterns based on the CMD risk.

Spontaneous version after preterm prelabor rupture of membranes.

Background: Preterm prelabor rupture of membranes (PPROM), defined as rupture of membranes before the onset of labor at < 37 weeks' gestation, affects approximately 3% of all pregnancies. For PPROM prior to 34 weeks' gestation, in the absence of contraindications to expectant management, antibiotics are administered to increase the latency period and reduce the incidence of maternal and neonatal infection. The latency period additionally provides an opportunity for fetal presentation to change, which impacts the mode of delivery.

Biodegradable macromers for implant bulk and surface engineering.

Macromers, polymeric molecules with at least two functional groups for cross-polymerization, are interesting materials to tailor mechanical, biochemical and degradative bulk and surface properties of implants for tissue regeneration. In this review we focus on macromers with at least one biodegradable building block. Manifold design options, such as choice of polymeric block(s), optional core molecule and reactive groups, as well as cross-co-polymerization with suitable anchor or linker molecules, allow the adaptation of macromer-based biomaterials towards specific application requirements in both hard and soft tissue regeneration.

High-dose testosterone treatment reduces monoamine oxidase A levels in the human brain: A preliminary report.

The sex hormones testosterone and estradiol influence brain structure and function and are implicated in the pathogenesis, prevalence and disease course of major depression. Recent research employing gender-affirming hormone treatment (GHT) of gender dysphoric individuals and utilizing positron emission tomography (PET) indicates increased serotonin transporter binding upon high-dosages of testosterone treatment. Here, we investigated the effects of GHT on levels of monoamine oxidase A (MAO-A), another key target of antidepressant treatment.

AI-enhanced simultaneous multiparametric F-FDG PET/MRI for accurate breast cancer diagnosis.

Purpose: To assess whether a radiomics and machine learning (ML) model combining quantitative parameters and radiomics features extracted from simultaneous multiparametric F-FDG PET/MRI can discriminate between benign and malignant breast lesions.

Methods: A population of 102 patients with 120 breast lesions (101 malignant and 19 benign) detected on ultrasound and/or mammography was prospectively enrolled. All patients underwent hybrid F-FDG PET/MRI for diagnostic purposes.

Single-lesion Prostate-specific Membrane Antigen Protein Expression (PSMA) and Response to [Lu]-PSMA-ligand Therapy in Patients with Castration-resistant Prostate Cancer.

Unlabelled: Initial reports of a clinical response in patients treated with the radioligand [Lu]-PSMA-617 for castration-resistant prostate cancer (CRPC) are promising, despite known inter- and intrapatient heterogeneity. In metastatic CRPC, we examined the association of baseline immunohistochemical (IHC) expression of prostate-specific membrane antigen (PSMA) in a single lesion and responsiveness to [Lu]-PSMA-617 therapy, measured as the PSMA maximum standardized uptake value (SUV). Between 2015 and 2020, 19 patients with multiple metastases underwent single-lesion biopsy, [Ga]-PSMA positron emission tomography (PET) imaging, and treatment with [Lu]-PSMA-617.

Discrimination, Microaggressions, and Perceptions of Institutional Response in an Academic Obstetrics and Gynecology Department.

Introduction Discrimination in the workplace remains a barrier to advancing diversity and inclusion in the physician workforce. This study sought to examine experiences of discrimination, microaggressions, and perceptions of the institution's response in an academic obstetrics and gynecology department. Method All obstetrics and gynecology faculty, fellows, and residents were invited to complete an anonymous, Institutional Review Board-approved cross-sectional survey from February through June 2019.

Characterization of endogenous bile acid composition in individuals with cold-activated brown adipose tissue.

Introduction: Bile acid signaling has been suggested to promote BAT activity in various experimental models. However, little is known if and how physiologic bile acid metabolism is linked to BAT function in humans. Here we investigated the association between BAT activity and circulating bile acid concentrations in lean and obese individuals.

Pregnancy complications, substance abuse, and prenatal care predict birthweight in adolescent mothers.

Background: Reduced birthweight is associated with adverse physical and mental health outcomes later in life. Children of adolescent mothers are at higher risk for reduced birthweight. The current study aimed to identify the key risk factors affecting birthweight in a well-characterized sample of adolescent mothers to inform preventive public health efforts.

Endocrine disrupting chemical-associated hair product use during pregnancy and gestational age at delivery: a pilot study.

Background: Prenatal endocrine disrupting chemical (EDC) exposure has been associated with increased risk of preterm birth. Non-Hispanic Black women have higher incidence of preterm birth compared to other racial/ethnic groups and may be disproportionately exposed to EDCs through EDC-containing hair products. However, research on the use of EDC-associated hair products during pregnancy and risk of preterm birth is lacking.

Lenvatinib Targets PDGFR-β Pericytes and Inhibits Synergy With Thyroid Carcinoma Cells: Novel Translational Insights.

Context: Pericyte populations abundantly express tyrosine kinases (eg, platelet-derived growth factor receptor-β [PDGFR-β]) and impact therapeutic response. Lenvatinib is a clinically available tyrosine kinase inhibitor that also targets PDGFR-β. Duration of therapeutic response was shorter in patients with greater disease burden and metastasis.

Functional Characterization of Adrenocortical Masses in Nononcologic Patients Using Ga-Pentixafor.

We aimed to investigate the diagnostic and prognostic value of Ga-pentixafor PET/CT imaging in noncancer patients with suspected adrenal masses. Sixty-four patients who had benign adrenal masses on CT were retrospectively included in our study. All patients underwent Ga-pentixafor PET/CT, and 56 of these patients subsequently underwent adrenalectomy.

BDNF rs6265 Genotype Influences Outcomes of Pharmacotherapy and Subthalamic Nucleus Deep Brain Stimulation in Early-Stage Parkinson's Disease.

Introduction: The efficacy of pharmacotherapy and deep brain stimulation of the subthalamic nucleus in treating Parkinson's disease motor symptoms is highly variable and may be influenced by patient genotype. The relatively common (prevalence about one in three) and protein-altering rs6265 single nucleotide polymorphism (C > T) in the gene BDNF has been associated with different clinical outcomes with levodopa.

Objective: We sought to replicate this reported association in early-stage Parkinson's disease subjects and to examine whether a difference in clinical outcomes was present with subthalamic nucleus deep brain stimulation.

ABCB1 and ABCG2 Together Limit the Distribution of ABCB1/ABCG2 Substrates to the Human Retina and the Single Nucleotide Polymorphism Q141K (c.421C> A) May Lead to Increased Drug Exposure.

The widely expressed and poly-specific ABC transporters breast cancer resistance protein (ABCG2) and P-glycoprotein (ABCB1) are co-localized at the blood-brain barrier (BBB) and have shown to limit the brain distribution of several clinically used ABCB1/ABCG2 substrate drugs. It is currently not known to which extent these transporters, which are also expressed at the blood-retinal barrier (BRB), may limit drug distribution to the human eye and whether the reduced-function single-nucleotide polymorphism (SNP) Q141K (c.421C > A) has an impact on retinal drug distribution.

PSMA Expression in 122 Treatment Naive Glioma Patients Related to Tumor Metabolism in C-Methionine PET and Survival.

Apart from its expression in benign and malignant prostate tissue, prostate specific membrane antigen (PSMA) was shown to be expressed specifically in the neovasculature of solid tumors. For gliomas only little information exists. Therefore, we aimed to correlate PSMA expression in gliomas to tumor metabolism by L-[S-methyl-C]methionine (MET) PET and survival.

Update on PET Tracer Development for Muscarinic Acetylcholine Receptors.

The muscarinic cholinergic system regulates peripheral and central nervous system functions, and, thus, their potential as a therapeutic target for several neurodegenerative diseases is undoubted. A clinically applicable positron emission tomography (PET) tracer would facilitate the monitoring of disease progression, elucidate the role of muscarinic acetylcholine receptors (mAChR) in disease development and would aid to clarify the diverse natural functions of mAChR regulation throughout the nervous system, which still are largely unresolved. Still, no mAChR PET tracer has yet found broad clinical application, which demands mAChR tracers with improved imaging properties.

Ambient PM gross β-activity and glucose levels during pregnancy.

Background: Exposure to ionizing radiation has been associated with insulin resistance and type 2 diabetes. In light of recent work showing an association between ambient particulate matter (PM) gross β-activity and gestational diabetes mellitus (GDM) among pregnant women, we examined pregnancy glucose levels in relation to PM gross β-activity to better understand this pathway.

Methods: Our study included 103 participants receiving prenatal care at Beth Israel Deaconess Medical Center in Boston, MA.

Reliability of task-specific neuronal activation assessed with functional PET, ASL and BOLD imaging.

Mapping the neuronal response during cognitive processing is of crucial importance to gain new insights into human brain function. BOLD imaging and ASL are established MRI methods in this endeavor. Recently, the novel approach of functional PET (fPET) was introduced, enabling absolute quantification of glucose metabolism at rest and during task execution in a single measurement.

A focus on critical aspects of uptake and transport of milk-derived extracellular vesicles across the Caco-2 intestinal barrier model.

Bovine milk-derived extracellular vesicles (EVs) hold promises as oral drug delivery systems. Since EV bioavailability studies are difficult to compare, key factors regarding EV uptake and intestinal permeability remain little understood. This work aims to critically study uptake and transport properties of milk-derived EVs across the intestinal barrier in vitro by standardization approaches.