Brown adipose tissue is associated with reduced weight loss and risk of cancer cachexia: A retrospective cohort study.

Background & Aims: Brown adipose tissue (BAT) has been mainly investigated as a potential target against cardiometabolic disease, but it has also been linked to cancer-related outcomes. Although preclinical data support that BAT and the thermogenic adipocytes in white adipose tissue may play an adverse role in the pathogenesis of cancer cachexia, results from studies in patients have reported inconsistent results. The purpose of this study was to examine the interrelationship between presence of detectable BAT, changes in body weight, and cachexia in patients with cancer.

Total-body positron emission tomography: a tool for systemic, quantitative evaluation of the inflammatory burden of psoriatic arthritis.

Objectives: To test the hypothesis that recently-developed total body-positron emission tomography (TB-PET) imaging with integrated computed tomography (CT) will enable low-dose, quantitative, domain-specific evaluation of the total inflammatory burden of psoriatic arthritis (PsA), and associate with established outcome measures of the clinical domains of PsA.

Methods: Seventy-one adult participants (40 with PsA, 16 with rheumatoid arthritis (RA), and 15 with osteoarthritis (OA)) underwent 20-min TB-PET/CT scans using [18F]FDG, a glucose analogue radiotracer. [18F]FDG uptake was assessed qualitatively and quantitatively.

Focusing on ligamentous soft tissue inflammation for the future understanding of early axial psoriatic arthritis.

Imaging has transformed the understanding of inflammatory and degenerative arthritis in both peripheral and axial disease. In axial inflammation, fat suppression magnetic resonance imaging (MRI) has unravelled the role of sub-fibrocartilaginous osteitis in axial spondyloarthritis and the role of peri-entheseal vertebral body osteitis and subsequent spinal new bone formation. Established or late-stage axial psoriatic arthritis (PsA) cases often exhibit impressive para-marginal or chunky syndesmophytosis on conventional X-ray that pathologically represents entheseal soft tissue ossification.

Role of Total Body PET/CT in Inflammatory Disorders.

Inflammatory disorders historically have been difficult to monitor with conventional PET imaging due to limitations including radiation exposure, lack of validated imaging biomarkers, low spatial resolution, and long acquisition durations. However, the recent development of long-axial field-of-view (LAFOV) PET/CT scanners may allow utilization of novel noninvasive biomarkers to diagnose, predict outcomes, and monitor therapeutic response of inflammatory conditions. LAFOV PET scanners can image most of the human body (if not the entire body) simultaneously in one bed position, with improved signal collection efficiency compared to conventional PET scanners.

Shifts in the spatiotemporal profile of inflammatory phenotypes of innate immune cells in the rat brain following acute intoxication with the organophosphate diisopropylfluorophosphate.

Acute intoxication with cholinesterase inhibiting organophosphates (OP) can produce life-threatening cholinergic crisis and status epilepticus (SE). Survivors often develop long-term neurological consequences, including spontaneous recurrent seizures (SRS) and impaired cognition. Numerous studies implicate OP-induced neuroinflammation as a pathogenic mechanism contributing to these chronic sequelae; however, little is known about the inflammatory phenotype of innate immune cells in the brain following acute OP intoxication.

Quantitative Total-Body Imaging of Blood Flow with High Temporal Resolution Early Dynamic F-Fluorodeoxyglucose PET Kinetic Modeling.

Unlabelled: Quantitative total-body PET imaging of blood flow can be performed with freely diffusible flow radiotracers such as O-water and C-butanol, but their short half-lives necessitate close access to a cyclotron. Past efforts to measure blood flow with the widely available radiotracer F-fluorodeoxyglucose (FDG) were limited to tissues with high F-FDG extraction fraction. In this study, we developed an early-dynamic F-FDG PET method with high temporal resolution kinetic modeling to assess total-body blood flow based on deriving the vascular transit time of F-FDG and conducted a pilot comparison study against a C-butanol reference.

The role of brown adipose tissue in branched-chain amino acid clearance in people.

Brown adipose tissue (BAT) in rodents appears to be an important tissue for the clearance of plasma branched-chain amino acids (BCAAs) contributing to improved metabolic health. However, the role of human BAT in plasma BCAA clearance is poorly understood. Here, we evaluate patients with prostate cancer who underwent positron emission tomography-computed tomography imaging after an injection of F-fluciclovine (L-leucine analog).

Temporal progression of tau pathology and neuroinflammation in a rhesus monkey model of Alzheimer's disease.

Introduction: The understanding of the pathological events in Alzheimer's disease (AD) has advanced dramatically, but the successful translation from rodent models into efficient human therapies is still problematic.

Methods: To examine how tau pathology can develop in the primate brain, we injected 12 macaques with a dual tau mutation (P301L/S320F) into the entorhinal cortex (ERC). An investigation was performed using high-resolution microscopy, magnetic resonance imaging (MRI), positron emission tomography (PET), and fluid biomarkers to determine the temporal progression of the pathology 3 and 6 months after the injection.

A longitudinal MRI and TSPO PET-based investigation of brain region-specific neuroprotection by diazepam versus midazolam following organophosphate-induced seizures.

Acute poisoning with organophosphorus cholinesterase inhibitors (OPs), such as OP nerve agents and pesticides, can cause life threatening cholinergic crisis and status epilepticus (SE). Survivors often experience significant morbidity, including brain injury, acquired epilepsy, and cognitive deficits. Current medical countermeasures for acute OP poisoning include a benzodiazepine to mitigate seizures.

Quantitative T mapping-based longitudinal assessment of brain injury and therapeutic rescue in the rat following acute organophosphate intoxication.

Acute intoxication with organophosphate (OP) cholinesterase inhibitors poses a significant public health risk. While currently approved medical countermeasures can improve survival rates, they often fail to prevent chronic neurological damage. Therefore, there is need to develop effective therapies and quantitative metrics for assessing OP-induced brain injury and its rescue by these therapies.

Fully automated whole brain segmentation from rat MRI scans with a convolutional neural network.

Background: Whole brain delineation (WBD) is utilized in neuroimaging analysis for data preprocessing and deriving whole brain image metrics. Current automated WBD techniques for analysis of preclinical brain MRI data show limited accuracy when images present with significant neuropathology and anatomical deformations, such as that resulting from organophosphate intoxication (OPI) and Alzheimer's Disease (AD), and inadequate generalizability.

Methods: A modified 2D U-Net framework was employed for WBD of MRI rodent brains, consisting of 27 convolutional layers, batch normalization, two dropout layers and data augmentation, after training parameter optimization.

Relationships between diagnostic imaging of first carpometacarpal osteoarthritis and pain, functional status, and disease progression: A systematic review.

Objective: To systematically review the association of pain, function, and progression in first carpometacarpal (CMC) osteoarthritis (OA) with imaging biomarkers and radiography-based staging.

Design: Database searches in PubMed, Embase, and the Cochrane Library, along with citation searching were conducted in accordance with published guidance. Data on the association of imaging with pain, functional status, and disease progression were extracted and synthesized, along with key information on study methodology such as sample sizes, use of control subjects, study design, number of image raters, and blinding.

EXPLORing Arthritis with Total-body Positron Emission Tomography.

Arthritis has significant adverse consequences on musculoskeletal tissues and often other organs of the body. Current methods for clinical evaluation of arthritis are suboptimal, and biomarkers that are objective and measurable indicators for monitoring of arthritis disease activity are in critical demand. Recently, total-body positron emission tomography (PET) has been developed that can collect imaging signals synchronously from the entire body at ultra-low doses and reduced scan times.

Time- and region-dependent blood-brain barrier impairment in a rat model of organophosphate-induced status epilepticus.

Acute organophosphate (OP) intoxication can trigger seizures that progress to status epilepticus (SE), and survivors often develop chronic morbidities, including spontaneous recurrent seizures (SRS). The pathogenic mechanisms underlying OP-induced SRS are unknown, but increased BBB permeability is hypothesized to be involved. Previous studies reported BBB leakage following OP-induced SE, but key information regarding time and regional distribution of BBB impairment during the epileptogenic period is missing.

Clinical, functional, and opportunistic CT metrics of sarcopenia at the point of imaging care: analysis of all-cause mortality.

Purpose: This study examines clinical, functional, and CT metrics of sarcopenia and all-cause mortality in older adults undergoing outpatient imaging.

Methods: The study included outpatients ≥ 65 years of age undergoing CT or PET/CT at a tertiary care institution. Assessments included screening questionnaires for sarcopenia (SARC-F) and frailty (FRAIL scale), and measurements of grip strength and usual gait speed (6 m course).

Total-Body Multiparametric PET Quantification of F-FDG Delivery and Metabolism in the Study of Coronavirus Disease 2019 Recovery.

Conventional whole-body static F-FDG PET imaging provides a semiquantitative evaluation of overall glucose metabolism without insight into the specific transport and metabolic steps. Here we demonstrate the ability of total-body multiparametric F-FDG PET to quantitatively evaluate glucose metabolism using macroparametric quantification and assess specific glucose delivery and phosphorylation processes using microparametric quantification for studying recovery from coronavirus disease 2019 (COVID-19). The study included 13 healthy subjects and 12 recovering COVID-19 subjects within 8 wk of confirmed diagnosis.

Novel Insights From Basic Science in Psoriatic Disease at the GRAPPA 2022 Annual Meeting.

Recent basic science advances in psoriatic disease (PsD) were presented and discussed at the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2022 annual meeting. Topics included clinical applications of biomarkers, what the future of biomarkers for PsD may hold, the challenges of developing biomarker research to the point of clinical utility, advances in total-body positron emission tomography/computed tomography imaging, and emerging concepts from single-cell studies in PsD.

Total-Body Multiparametric PET Quantification of F-FDG Delivery and Metabolism in the Study of COVID-19 Recovery.

Unlabelled: Conventional whole-body F-FDG PET imaging provides a semi-quantitative evaluation of overall glucose metabolism without gaining insight into the specific transport and metabolic steps. Here we demonstrate the ability of total-body multiparametric F-FDG PET to quantitatively evaluate glucose metabolism using macroparametric quantification and assess specific glucose delivery and phosphorylation processes using microparametric quantification for studying recovery from coronavirus disease 2019 (COVID-19).

Methods: The study included thirteen healthy subjects and twelve recovering COVID-19 subjects within eight weeks of confirmed diagnosis.

Neural correlates and effect of jealousy on cognitive flexibility in the female titi monkey (Plecturocebus cupreus).

Jealousy is a social emotion that manifests as behavioral reactions from an individual toward a threat to a valuable relationship. Monogamous species exhibit jealousy-type behaviors as an adaptive response to preserve the relationship. Jealousy is also a complex, negatively-valenced emotion which may include fear of loss, anxiety, suspiciousness, and anger.

Increased Striatal Presynaptic Dopamine in a Nonhuman Primate Model of Maternal Immune Activation: A Longitudinal Neurodevelopmental Positron Emission Tomography Study With Implications for Schizophrenia.

Background: Epidemiological studies suggest that maternal immune activation (MIA) is a significant risk factor for future neurodevelopmental disorders, including schizophrenia (SZ), in offspring. Consistent with findings in SZ research and work in rodent systems, preliminary cross-sectional findings in nonhuman primates suggest that MIA is associated with dopaminergic hyperfunction in young adult offspring.

Methods: In this unique prospective longitudinal study, we used [F]fluoro-l-m-tyrosine positron emission tomography to examine the developmental time course of striatal presynaptic dopamine synthesis in male rhesus monkeys born to dams (n = 13) injected with a modified form of the inflammatory viral mimic, polyinosinic:polycytidylic acid [poly(I:C)], in the late first trimester.

Regulation of beige adipocyte thermogenesis by the cold-repressed ER protein NNAT.

Objective: Cold stimuli trigger the conversion of white adipose tissue into beige adipose tissue, which is capable of non-shivering thermogenesis. However, what process drives this activation of thermogenesis in beige fat is not well understood. Here, we examine the ER protein NNAT as a regulator of thermogenesis in adipose tissue.