Mechanisms by Which the Fun for Wellness Intervention May Promote Subjective Well-Being in Adults with Obesity: a Reanalysis Using Baseline Target Moderation.

Fun For Wellness (FFW) is a self-efficacy theory-based online behavioral intervention that aims to promote growth in physical activity and well-being. The FFW conceptual model for the promotion of subjective well-being posits that FFW exerts both a positive direct effect, and a positive indirect effect through well-being self-efficacy, on subjective well-being. Subjective well-being is defined in FFW as an individual's satisfaction with their status in seven key domains of their life. Well-being self-efficacy is defined in FFW as the degree to which an individual perceives that they have the capability to attain a positive status in seven key domains of their life. The objective of this study was to use baseline target moderation to assess variation in the impact of FFW on subjective well-being dimensions in adults with obesity. Data (N = 667) from the Well-Being and Physical Activity Study (ClinicalTrials.gov, identifier: NCT03194854) were reanalyzed. There was evidence that well-being self-efficacy at baseline moderated the direct effect of FFW on well-being self-efficacy at 30 days post-baseline for the occupational and psychological dimensions. Both of these findings suggest a "compensatory" effect. Similarly, there was evidence that well-being self-efficacy at baseline moderated the indirect effect of FFW on subjective well-being at 60 days post-baseline through well-being self-efficacy at 30 days post-baseline for the occupational and psychological dimensions. Both of these findings suggest a "compensatory" effect. Finally, there was evidence that well-being self-efficacy at baseline moderated the direct effect of FFW on subjective well-being at 60 days post-baseline for the community, occupational, and physical dimensions. Each of these three findings suggests some version of a "rich-get-richer" effect. In summary, results provide both supportive and unsupportive (i.e., interpersonal, economic, and overall dimensions) evidence regarding variation in the impact of the FFW intervention and should impact the design of future FFW trials.

Measurement of Physical Activity Self-Efficacy in Adults With Obesity: A Latent Variable Approach to Explore Dimensionality, Temporal Invariance, and External Validity.

The objective of this study was to improve the measurement of physical activity self-efficacy (PASE) in adults with obesity. To accomplish this objective, a latent variable approach was used to explore dimensionality, temporal invariance, and external validity of responses to a newly developed battery of PASE scales. Data (Nbaseline = 461 and N30 days postbaseline = 427) from the Well-Being and Physical Activity Study (ClinicalTrials.gov, identifier: NCT03194854), which deployed the Fun For Wellness intervention, were analyzed. A two-dimensional factor structure explained responses to each PASE scale at baseline. There was strong evidence for at least partial temporal measurement invariance for this two-dimensional structure in each PASE scale. There was mixed evidence that the effectiveness of the Fun For Wellness intervention exerted a direct effect on latent PASE in adults with obesity at 30 days postbaseline (i.e., external validity) of this two-dimensional structure.

A highly reproducible method for the measurement of [6-O-methyl-11 C]diprenorphine and its radio-metabolites based on solid-phase extraction and radio-high-pressure liquid chromatography.

Described here is a method for the measurement of the radio-metabolites of the positron emission tomography radiotracer [6-O-methyl-11 C]diprenorphine ([11 C]diprenorphine) using in-line solid-phase extraction (SPE) combined with radio-high-pressure liquid chromatography analysis. We believe that this method offers a reliable and reproducible approach to [11 C]diprenorphine metabolite analysis. In addition, different SPE stationary phases are assessed for their efficiency for loading, retention and elution of the parent molecule and its metabolites. Having assessed C4, phenyl and C18 stationary phase, we concluded that a C18 SPE was optimal for our method. Finally, in silico predictions of diprenorphine metabolism were compared with in vivo metabolism of [11 C]diprenorphine induced by hepatic microsomal digestion and analysed by matrix-assisted laser desorption/ionisation mass spectrometry. It was found that there was a high degree of agreement between the two methods and in particular the formation of the diprenorphine-3-glucuronide metabolite.

Circadian influence on inflammatory response during cardiovascular disease.

Circadian rhythms follow a 24 h day and night cycle, regulate vital physiological processes, and are especially relevant to cardiovascular growth, renewal, repair, and remodeling. A recent flurry of clinical and experimental studies reveals a profound circadian influence on immune responses in cardiovascular disease. The first section of this review summarizes the importance of circadian rhythms for cardiovascular health and disease. The second section introduces the circadian nature of inflammatory responses. The third section combines these to elucidate a new role for the circadian system, influencing inflammation in heart disease, especially myocardial infarction. Particular focus is on circadian regulation of the NACHT, LRR, and PYD domains-containing protein 3 inflammasome, neutrophils, monocytes/macrophages, and T cells involved in cardiac repair. A role for biological sex is noted. The final section explores circadian influences on inflammation in other major cardiovascular conditions. Circadian regulation of inflammation has profound implications for benefitting the diagnosis, treatment, and prognosis of patients with cardiovascular disease.

Effectiveness of the Fun for Wellness Online Behavioral Intervention to Promote Well-Being Actions in Adults With Obesity or Overweight: A Randomized Controlled Trial.

The purpose of this study was to evaluate the effectiveness of the Fun For Wellness (FFW) online intervention to increase well-being actions in adults with obesity in the United States in relatively uncontrolled settings. The FFW intervention is guided by self-efficacy theory. The study design was a large-scale, prospective, double-blind, and parallel-group randomized controlled trial. Data collection occurred at baseline, 30 days after baseline, and 60 days after baseline. Participants (N = 667) who were assigned to the FFW group (nFFW = 331) were provided with 30 days of 24-hr access to FFW. Supportive evidence was provided for the effectiveness of FFW in real-world settings to promote, either directly or indirectly, three dimensions of well-being actions: community, occupational, and psychological. This study shows that theory-based intervention may be effective in promoting well-being actions in adults with obesity in the United States.

3D DESI-MS lipid imaging in a xenograft model of glioblastoma: a proof of principle.

Desorption electrospray ionisation mass spectrometry (DESI-MS) can image hundreds of molecules in a 2D tissue section, making it an ideal tool for mapping tumour heterogeneity. Tumour lipid metabolism has gained increasing attention over the past decade; and here, lipid heterogeneity has been visualised in a glioblastoma xenograft tumour using 3D DESI-MS imaging. The use of an automatic slide loader automates 3D imaging for high sample-throughput. Glioblastomas are highly aggressive primary brain tumours, which display heterogeneous characteristics and are resistant to chemotherapy and radiotherapy. It is therefore important to understand biochemical contributions to their heterogeneity, which may be contributing to treatment resistance. Adjacent sections to those used for DESI-MS imaging were used for H&E staining and immunofluorescence to identify different histological regions, and areas of hypoxia. Comparing DESI-MS imaging with biological staining allowed association of different lipid species with hypoxic and viable tissue within the tumour, and hence mapping of molecularly different tumour regions in 3D space. This work highlights that lipids are playing an important role in the heterogeneity of this xenograft tumour model, and DESI-MS imaging can be used for lipid 3D imaging in an automated fashion to reveal heterogeneity, which is not apparent in H&E stains alone.

P-glycoprotein overactivity in epileptogenic developmental lesions measured in vivo using (R)-[11 C]verapamil PET.

OBJECTIVE: Overexpression of the drug transporter P-glycoprotein (P-gp) is thought to be involved in drug-resistance in epilepsy by extrusion of antiepileptic drugs (AEDs). We used positron emission tomography (PET) and the P-gp substrate radiotracer (R)-[11 C]verapamil (VPM) together with the third-generation P-gp inhibitor tariquidar (TQD) to evaluate P-gp function in individuals with drug-resistant epileptogenic developmental lesions. METHODS: Twelve healthy controls (7 male, median age 45, range 35-55 years), and two patients with epileptogenic developmental lesions (2 male, aged 24 and 62 years) underwent VPM-PET scans before and 60 minutes after a 30-minute infusion of 2 and 3 mg/kg TQD. The influx rate constant, VPM-K1 , was estimated from the first 10 minutes of dynamic data using a single-tissue compartment model with a VPM plasma input function. Statistical parametric mapping (SPM) analysis was used to compare individual patients with the healthy controls. RESULTS: At baseline, SPM voxel-based analysis revealed significantly lower uptake of VPM corresponding to the area of the epileptogenic developmental lesion compared to 12 healthy controls (P < .048). This was accentuated following P-gp inhibition with TQD. After TQD, the uptake of VPM was significantly lower in the area of the epileptogenic developmental lesion compared to controls (P < .002). SIGNIFICANCE: This study provides further evidence of P-gp overactivity in patients with drug-resistant epilepsy, irrespective of the type of lesion. Identifying P-gp overactivity as an underlying contributor to drug-resistance in individual patients will enable novel treatment strategies aimed at overcoming or reversing P-gp overactivity.

Targeting the MAPK7/MMP9 axis for metastasis in primary bone cancer.

Metastasis is the leading cause of cancer-related death. This multistage process involves contribution from both tumour cells and the tumour stroma to release metastatic cells into the circulation. Circulating tumour cells (CTCs) survive circulatory cytotoxicity, extravasate and colonise secondary sites effecting metastatic outcome. Reprogramming the transcriptomic landscape is a metastatic hallmark, but detecting underlying master regulators that drive pathological gene expression is a key challenge, especially in childhood cancer. Here we used whole tumour plus single-cell RNA-sequencing in primary bone cancer and CTCs to perform weighted gene co-expression network analysis to systematically detect coordinated changes in metastatic transcript expression. This approach with comparisons applied to data collected from cell line models, clinical samples and xenograft mouse models revealed mitogen-activated protein kinase 7/matrix metallopeptidase 9 (MAPK7/MMP9) signalling as a driver for primary bone cancer metastasis. RNA interference knockdown of MAPK7 reduces proliferation, colony formation, migration, tumour growth, macrophage residency/polarisation and lung metastasis. Parallel to these observations were reduction of activated interleukins IL1B, IL6, IL8 plus mesenchymal markers VIM and VEGF in response to MAPK7 loss. Our results implicate a newly discovered, multidimensional MAPK7/MMP9 signalling hub in primary bone cancer metastasis that is clinically actionable.

Effectiveness of the Fun for Wellness Web-Based Behavioral Intervention to Promote Physical Activity in Adults With Obesity (or Overweight): Randomized Controlled Trial.

BACKGROUND: Insufficient physical activity in the adult population is a global pandemic. Fun for Wellness (FFW) is a self-efficacy theory- and Web-based behavioral intervention developed to promote growth in well-being and physical activity by providing capability-enhancing opportunities to participants. OBJECTIVE: This study aimed to evaluate the effectiveness of FFW to increase physical activity in adults with obesity in the United States in a relatively uncontrolled setting. METHODS: This was a large-scale, prospective, double-blind, parallel-group randomized controlled trial. Participants were recruited through an online panel recruitment company. Adults with overweight were also eligible to participate, consistent with many physical activity-promoting interventions for adults with obesity. Also consistent with much of the relevant literature the intended population as simply adults with obesity. Eligible participants were randomly assigned to the intervention (ie, FFW) or the usual care (ie, UC) group via software code that was written to accomplish equal allocations to the FFW and UC groups. Data collection was Web based, fully automated, and occurred at three time points: baseline, 30 days after baseline (T2), and 60 days after baseline (T3). Participants (N=461) who were assigned to the FFW group (nFFW=219) were provided with 30 days of 24-hour access to the Web-based intervention. A path model was fit to the data consistent with the FFW conceptual model for the promotion of physical activity. RESULTS: There was evidence for a positive direct effect of FFW on transport-related physical activity self-efficacy (beta=.22, P=.02; d=0.23), domestic-related physical activity self-efficacy (beta=.22, P=.03; d=0.22), and self-efficacy to regulate physical activity (beta=.16, P=.01; d=0.25) at T2. Furthermore, there was evidence for a positive indirect effect of FFW on physical activity at T3 through self-efficacy to regulate physical activity at T2 (beta=.42, 95% CI 0.06 to 1.14). Finally, there was evidence for a null direct effect of FFW on physical activity (beta=1.04, P=.47; d=0.07) at T3. CONCLUSIONS: This study provides some initial evidence for both the effectiveness (eg, a positive indirect effect of FFW on physical activity through self-efficacy to regulate physical activity) and the ineffectiveness (eg, a null direct effect of FFW on physical activity) of the FFW Web-based behavioral intervention to increase physical activity in adults with obesity in the United States. More broadly, FFW is a scalable Web-based behavioral intervention that may effectively, although indirectly, promote physical activity in adults with obesity and therefore may be useful in responding to the global pandemic of insufficient physical activity in this at-risk population. Self-efficacy to regulate physical activity appears to be a mechanism by which FFW may indirectly promote physical activity in adults with obesity. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT03194854; https://clinicaltrials.gov/ct2/show/NCT03194854.

Effectiveness of the fun for wellness online behavioral intervention to promote well-being and physical activity: protocol for a randomized controlled trial.

BACKGROUND: Fun For Wellness (FFW) is an online behavioral intervention developed to encourage growth in well-being by providing capability-enhancing learning opportunities to participants. Self-efficacy theory guides the conceptual model underlying the FFW intervention. Some initial evidence has been provided for the efficacy of FFW to promote: well-being self-efficacy; interpersonal, community, psychological and economic subjective well-being; and, interpersonal and physical well-being actions. The purpose of this paper is to describe the protocol for a new randomized controlled trial (RCT) designed to provide the first investigation of the effectiveness of FFW to increase well-being and physical activity in adults with obesity in the United States of America. METHODS: The study design is a large-scale, prospective, parallel group RCT. Approximately 9 hundred participants will be randomly assigned to the FFW or Usual Care (UC) group to achieve a 1:1 group (i.e. , FFW: UC) assignment. Participants will be recruited through an online panel recruitment company. Data collection, including determination of eligibility, will be conducted online and enrollment is scheduled to begin on 8 August 2018. Data collection will occur at baseline, 30 days and 60 days after baseline. Instruments to measure demographic information, anthropometric characteristics, self-efficacy, physical activity and well-being will be included in the battery. Data will be modeled under an intent to treat approach and/or a complier average causal effect approach depending on the level of observed engagement with the intervention. DISCUSSION: The effectiveness trial described in this paper builds upon the 2015 FFW efficacy trial and has the potential to be important for at least three reasons. The first reason is based upon a general scientific approach that the potential utility of interventions should be evaluated under both ideal (e.g., more controlled) and real-world (e.g., less controlled) conditions. The second reason is based upon the global need for readily scalable online behavioral interventions that effectively promote physical activity in adults. The third reason is based upon the troubling global trend toward obesity along with evidence for obesity as a risk factor for several major non-communicable diseases. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT03194854 , registered 21 June 2017.

Accelerometer-based assessment of physical activity within the Fun For Wellness online behavioral intervention: protocol for a feasibility study.

BACKGROUND: Fun For Wellness (FFW) is an online behavioral intervention designed to promote growth in well-being and physical activity by providing capability-enhancing learning opportunities to participants. The conceptual framework for the FFW intervention is guided by self-efficacy theory. Evidence has been provided for the efficacy of FFW to promote self-reported free-living physical well-being actions in adults who comply with the intervention. The objective of this manuscript is to describe the protocol for a feasibility study designed to address uncertainties regarding the inclusion of accelerometer-based assessment of free-living physical activity within the FFW online intervention among adults with obesity in the United States of America (USA). METHOD: The study design is a prospective, double-blind, parallel group randomized pilot trial. Thirty participants will be randomly assigned to the FFW or usual care (UC) group to achieve a 1:1 group (i.e., FFW:UC) assignment. Recruitment of participants is scheduled to begin on 29 April 2019 at a local bariatric services center within a major healthcare organization in the Midwest of the USA. There are five eligibility criteria for participation in this study: (1) between 18 and 64 years old, (2) a body mass index ≥ 25.00 kg/m2, (3) ability to access the online intervention, (4) the absence of simultaneous enrollment in another intervention program promoting physical activity, and (5) willingness to comply with instructions for physical activity monitoring. Eligibility verification and data collection will be conducted online. Three waves of data will be collected over a 13-week period. Instruments designed to measure demographic information, anthropometric characteristics, acceptability and feasibility of accelerometer-based assessment of physical activity, self-efficacy, and well-being will be included in the study. Data will be analyzed using descriptive statistics (e.g., recruitment rates), Pearson's correlation coefficient, Bland-Altman analyses, and inferential statistical models under both an intent to treat approach and a complier average causal effect approach. DISCUSSION: Results are intended to inform the preparation of a future definitive randomized controlled trial. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03906942, registered 8 April 2019. TRIAL FUNDING: The Erwin and Barbara Mautner Charitable Foundation and the Michigan State University College of Education.

Enhanced Fatty Acid Scavenging and Glycerophospholipid Metabolism Accompany Melanocyte Neoplasia Progression in Zebrafish.

Alterations in lipid metabolism in cancer cells impact cell structure, signaling, and energy metabolism, making lipid metabolism a potential diagnostic marker and therapeutic target. In this study, we combined PET, desorption electrospray ionization-mass spectrometry (DESI-MS), nonimaging MS, and transcriptomic analyses to interrogate changes in lipid metabolism in a transgenic zebrafish model of oncogenic RAS-driven melanocyte neoplasia progression. Exogenous fatty acid uptake was detected in melanoma tumor nodules by PET using the palmitic acid surrogate tracer 14(R,S)-18F-fluoro-6-thia-heptadecanoic acid ([18F]-FTHA), consistent with upregulation of genes associated with fatty acid uptake found through microarray analysis. DESI-MS imaging revealed that FTHA uptake in tumors was heterogeneous. Transcriptome and lipidome analyses further highlighted dysregulation of glycerophospholipid pathways in melanoma tumor nodules, including increased abundance of phosphatidyl ethanolamine and phosphatidyl choline species, corroborated by DESI-MS, which again revealed heterogeneous phospholipid composition in tumors. Overexpression of the gene encoding lipoprotein lipase (LPL), which was upregulated in zebrafish melanocyte tumor nodules and expressed in the majority of human melanomas, accelerated progression of oncogenic RAS-driven melanocyte neoplasia in zebrafish. Depletion or antagonism of LPL suppressed human melanoma cell growth; this required simultaneous fatty acid synthase (FASN) inhibition when FASN expression was also elevated. Collectively, our findings implicate fatty acid acquisition as a possible therapeutic target in melanoma, and the methods we developed for monitoring fatty acid uptake have potential for diagnosis, patient stratification, and monitoring pharmacologic response. SIGNIFICANCE: These findings demonstrate the translational potential of monitoring fatty acid uptake and identify lipoprotein lipase as a potential therapeutic target in melanoma.

Efficacy of the Fun For Wellness Online Intervention to Promote Well-Being Actions: A Secondary Data Analysis.

OBJECTIVE: Fun For Wellness (FFW) is a new online intervention designed to promote growth in well-being by providing capability-enhancing learning opportunities (e.g., play an interactive game) to participants. The purpose of this study was to provide an initial evaluation of the efficacy of the FFW intervention to increase well-being actions. MATERIALS AND METHODS: The study design was a secondary data analysis of a large-scale prospective, double-blind, parallel-group randomized controlled trial. Data were collected at baseline and 30 and 60 days postbaseline. A total of 479 adult employees at a major university in the southeast of the United States of America were enrolled. Participants who were randomly assigned to the FFW group were provided with 30 days of 24-hour access to the intervention. A two-class linear regression model with complier average causal effect estimation was fitted to well-being actions scores at 30 and 60 days. RESULTS: Intent-to-treat analysis provided evidence that the effect of being assigned to the FFW intervention, without considering actual participation in the FFW intervention, had a null effect on each dimension of well-being actions at 30 and 60 days. Participants who complied with the FFW intervention, however, had significantly higher well-being actions scores, compared to potential compliers in the Usual Care group, in the interpersonal dimension at 60 days, and the physical dimension at 30 days. CONCLUSIONS: Results from this secondary data analysis provide some supportive evidence for both the efficacy of and possible revisions to the FFW intervention in regard to promoting well-being actions.

Multi-modal imaging of long-term recovery post-stroke by positron emission tomography and matrix-assisted laser desorption/ionisation mass spectrometry.

RATIONALE: Stroke is a leading cause of disability worldwide. Understanding the recovery process post-stroke is essential; however, longer-term recovery studies are lacking. In vivo positron emission tomography (PET) can image biological recovery processes, but is limited by spatial resolution and its targeted nature. Untargeted mass spectrometry imaging offers high spatial resolution, providing an ideal ex vivo tool for brain recovery imaging. METHODS: Magnetic resonance imaging (MRI) was used to image a rat brain 48 h after ischaemic stroke to locate the infarcted regions of the brain. PET was carried out 3 months post-stroke using the tracers [18 F]DPA-714 for TSPO and [18 F]IAM6067 for sigma-1 receptors to image neuroinflammation and neurodegeneration, respectively. The rat brain was flash-frozen immediately after PET scanning, and sectioned for matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) imaging. RESULTS: Three months post-stroke, PET imaging shows minimal detection of neurodegeneration and neuroinflammation, indicating that the brain has stabilised. However, MALDI-MS images reveal distinct differences in lipid distributions (e.g. phosphatidylcholine and sphingomyelin) between the scar and the healthy brain, suggesting that recovery processes are still in play. It is currently not known if the altered lipids in the scar will change on a longer time scale, or if they are stabilised products of the brain post-stroke. CONCLUSIONS: The data demonstrates the ability to combine MALD-MS with in vivo PET to image different aspects of stroke recovery.

Efficacy of the Fun For Wellness Online Intervention to Promote Multidimensional Well-Being: a Randomized Controlled Trial.

Subjective well-being refers to people's level of satisfaction with life as a whole and with multiple dimensions within it. Interventions that promote subjective well-being are important because there is evidence that physical health, mental health, substance use, and health care costs may be related to subjective well-being. Fun For Wellness (FFW) is a new online universal intervention designed to promote growth in multiple dimensions of subjective well-being. The purpose of this study was to provide an initial evaluation of the efficacy of FFW to increase subjective well-being in multiple dimensions in a universal sample. The study design was a prospective, double-blind, parallel group randomized controlled trial. Data were collected at baseline and 30 and 60 days-post baseline. A total of 479 adult employees at a major university in the southeast of the USA were enrolled. Recruitment, eligibility verification, and data collection were conducted online. Measures of interpersonal, community, occupational, physical, psychological, economic (i.e., I COPPE), and overall subjective well-being were constructed based on responses to the I COPPE Scale. A two-class linear regression model with complier average causal effect estimation was imposed for each dimension of subjective well-being. Participants who complied with the FFW intervention had significantly higher subjective well-being, as compared to potential compliers in the Usual Care group, in the following dimensions: interpersonal at 60 days, community at 30 and 60 days, psychological at 60 days, and economic at 30 and 60 days. Results from this study provide some initial evidence for both the efficacy of, and possible revisions to, the FFW intervention.

Radiosynthesis of no-carrier-added meta-[124I]iodobenzylguanidine for PET imaging of metastatic neuroblastoma.

Meta-iodobenzylguanidine (mIBG) has been radiolabelled at the no-carrier-added level with [124I] for a proof of concept study to assess the diagnostic accuracy of [124I]mIBG PET/CT in detecting metastatic deposits in patients diagnosed with metastatic neuroblastoma. Radiolabelling of mIBG was achieved via the iododesilylation reaction between [124I]sodium iodide and meta-trimethylsilylbenzylguanidine. [124I]mIBG was produced in 62-70 % radioiodide incorporation yield from [124I]sodium iodide. The average amount of formulated [124I]mIBG was 359 MBq (range 344-389 MBq) with an average specific radioactivity of 4.1 TBq µmol-1 (range 1.8-5.9 TBq µmol-1) at end of synthesis.

Development & automation of a novel [(18)F]F prosthetic group, 2-[(18)F]-fluoro-3-pyridinecarboxaldehyde, and its application to an amino(oxy)-functionalised Aß peptide.

2-[(18)F]-Fluoro-3-pyridinecarboxaldehyde ([(18)F]FPCA) is a novel, water-soluble prosthetic group. It's radiochemistry has been developed and fully-automated for application in chemoselective radiolabelling of amino(oxy)-derivatised RI-OR2-TAT peptide, (Aoa-k)-RI-OR2-TAT, using a GE TRACERlab FX-FN. RI-OR2-TAT is a brain-penetrant, retro-inverso peptide that binds to amyloid species associated with Alzheimer's Disease. Radiolabelled (Aoa-k)-RI-OR2-TAT was reproducibly synthesised and the product of the reaction with FPCA has been fully characterised. In-vivo biodistribution of [(18)F]RI-OR2-TAT has been measured in Wistar rats.

Automation of [(18) F]fluoroacetaldehyde synthesis: application to a recombinant human interleukin-1 receptor antagonist (rhIL-1RA).

[(18) F]Fluoroacetaldehyde is a biocompatible prosthetic group that has been implemented pre-clinically using a semi-automated remotely controlled system. Automation of radiosyntheses permits use of higher levels of [(18) F]fluoride whilst minimising radiochemist exposure and enhancing reproducibility. In order to achieve full-automation of [(18) F]fluoroacetaldehyde peptide radiolabelling, a customised GE Tracerlab FX-FN with fully programmed automated synthesis was developed. The automated synthesis of [(18) F]fluoroacetaldehyde is carried out using a commercially available precursor, with reproducible yields of 26% ± 3 (decay-corrected, n = 10) within 45 min. Fully automated radiolabelling of a protein, recombinant human interleukin-1 receptor antagonist (rhIL-1RA), with [(18) F]fluoroacetaldehyde was achieved within 2 h. Radiolabelling efficiency of rhIL-1RA with [(18) F]fluoroacetaldehyde was confirmed using HPLC and reached 20% ± 10 (n = 5). Overall RCY of [(18) F]rhIL-1RA was 5% ± 2 (decay-corrected, n = 5) within 2 h starting from 35 to 40 GBq of [(18) F]fluoride. Specific activity measurements of 8.11-13.5 GBq/µmol were attained (n = 5), a near three-fold improvement of those achieved using the semi-automated approach. The strategy can be applied to radiolabelling a range of peptides and proteins with [(18) F]fluoroacetaldehyde analogous to other aldehyde-bearing prosthetic groups, yet automation of the method provides reproducibility thereby aiding translation to Good Manufacturing Practice manufacture and the transformation from pre-clinical to clinical production.

Striatal opioid receptor availability is related to acute and chronic pain perception in arthritis: does opioid adaptation increase resilience to chronic pain?

The experience of pain in humans is modulated by endogenous opioids, but it is largely unknown how the opioid system adapts to chronic pain states. Animal models of chronic pain point to upregulation of opioid receptors (OpR) in the brain, with unknown functional significance. We sought evidence for a similar relationship between chronic pain and OpR availability in humans. Using positron emission tomography and the radiotracer (11)C-diprenorphine, patients with arthritis pain (n = 17) and healthy controls (n = 9) underwent whole-brain positron emission tomography scanning to calculate parametric maps of OpR availability. Consistent with the upregulation hypothesis, within the arthritis group, greater OpR availability was found in the striatum (including the caudate) of patients reporting higher levels of recent chronic pain, as well as regions of interest in the descending opioidergic pathway including the anterior cingulate cortex, thalamus, and periaqueductal gray. The functional significance of striatal changes were clarified with respect to acute pain thresholds: data across patients and controls revealed that striatal OpR availability was related to reduced pain perception. These findings are consistent with the view that chronic pain may upregulate OpR availability to dampen pain. Finally, patients with arthritis pain, compared with healthy controls, had overall less OpR availability within the striatum specifically, consistent with the greater endogenous opioid binding that would be expected in chronic pain states. Our observational evidence points to the need for further studies to establish the causal relationship between chronic pain states and OpR adaptation.

The automated radiosynthesis and purification of the opioid receptor antagonist, [6-O-methyl-11C]diprenorphine on the GE TRACERlab FXFE radiochemistry module.

[6-O-Methyl-(11)C]diprenorphine ([(11)C]diprenorphine) is a positron emission tomography ligand used to probe the endogenous opioid system in vivo. Diprenorphine acts as an antagonist at all of the opioid receptor subtypes, that is, µ (mu), κ (kappa) and δ (delta). The radiosynthesis of [(11)C]diprenorphine using [(11)C]methyl iodide produced via the 'wet' method on a home-built automated radiosynthesis set-up has been described previously. Here, we describe a modified synthetic method to [(11)C]diprenorphine performed using [(11)C]methyl iodide produced via the gas phase method on a GE TRACERlab FXFE radiochemistry module. Also described is the use of [(11)C]methyl triflate as the carbon-11 methylating agent for the [(11)C]diprenorphine syntheses. [(11)C]Diprenorphine was produced to good manufacturing practice standards for use in a clinical setting. In comparison to previously reported [(11)C]diprenorphine radiosyntheisis, the method described herein gives a higher specific activity product which is advantageous for receptor occupancy studies. The radiochemical purity of [(11)C]diprenorphine is similar to what has been reported previously, although the radiochemical yield produced in the method described herein is reduced, an issue that is inherent in the gas phase radiosynthesis of [(11)C]methyl iodide. The yields of [(11)C]diprenorphine are nonetheless sufficient for clinical research applications. Other advantages of the method described herein are an improvement to both reproducibility and reliability of the production as well as simplification of the purification and formulation steps. We suggest that our automated radiochemistry route to [(11)C]diprenorphine should be the method of choice for routine [(11)C]diprenorphine productions for positron emission tomography studies, and the production process could easily be transferred to other radiochemistry modules such as the TRACERlab FX C pro.