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Funder: Akademiska Sjukhuset; doi: http://dx.doi.org/10.13039/501100005423, Funder: Uppsala University, PURPOSE: [11C]Metomidate positron emission tomography (PET) is currently used for staging of adrenocortical carcinoma and for lateralization in primary aldosteronism (PA). Due to the short half-life of carbon-11 and a high non-specific liver uptake of [11C]metomidate there is a need for improved adrenal imaging methods. In a previous pre-clinical study para-chloro-2-[18F]fluoroethyletomidate has been proven to be a specific adrenal tracer. The objective is to perform a first evaluation of para-chloro-2-[18F]fluoroethyletomidate positron emission computed tomography ([18F]CETO-PET/CT) in patients with adrenal tumours and healthy volunteers. METHODS: Fifteen patients underwent [18F]CETO-PET/CT. Five healthy volunteers were recruited for test-retest analysis and three out of the five underwent additional [15O]water PET/CT to measure adrenal blood flow. Arterial blood sampling and tracer metabolite analysis was performed. The kinetics of [18F]CETO were assessed and simplified quantitative methods were validated by comparison to outcome measures of tracer kinetic analysis. RESULTS: Uptake of [18F]CETO was low in the liver and high in adrenals. Initial metabolization was rapid, followed by a plateau. The kinetics of [18F]CETO in healthy adrenals and all adrenal pathologies, except for adrenocortical carcinoma, were best described by an irreversible single-tissue compartment model. Standardized uptake values (SUV) correlated well with the uptake rate constant K1. Both K1 and SUV were highly correlated to adrenal blood flow in healthy controls. Repeatability coefficients of K1, SUV65-70, and SUV120 were 25, 22, and 17%. CONCLUSIONS: High adrenal uptake combined with a low unspecific liver uptake suggests that 18F]CETO is a suitable tracer for adrenal imaging. Adrenal SUV, based on a whole-body scan at 1 h p.i., correlated well with the net uptake rate Ki. TRIAL REGISTRATION: ClinicalTrials.gov , NCT05361083 Retrospectively registered 29 April 2022. at, https://clinicaltrials.gov/ct2/show/NCT05361083.

It has been extensively debated whether selective serotonin reuptake inhibitors (SSRIs) are more efficacious than placebo in affective disorders, and it is not fully understood how SSRIs exert their beneficial effects. Along with serotonin transporter blockade, altered dopamine signaling and psychological factors may contribute. In this randomized clinical trial of participants with social anxiety disorder (SAD) we investigated how manipulation of verbally-induced expectancies, vital for placebo response, affect brain monoamine transporters and symptom improvement during SSRI treatment. Twenty-seven participants with SAD (17 men, 10 women), were randomized, to 9 weeks of overt or covert treatment with escitalopram 20 mg. The overt group received correct treatment information whereas the covert group was treated deceptively with escitalopram, described as an active placebo in a cover story. Before and after treatment, patients underwent positron emission tomography (PET) assessments with the [C-11]DASB and [C-11]PE2I radiotracers, probing brain serotonin (SERT) and dopamine (DAT) transporters. SAD symptoms were measured by the Liebowitz Social Anxiety Scale. Overt was superior to covert SSRI treatment, resulting in almost a fourfold higher rate of responders. PET results showed that SERT occupancy after treatment was unrelated to anxiety reduction and equally high in both groups. In contrast, DAT binding decreased in the right putamen, pallidum, and the left thalamus with overt SSRI treatment, and increased with covert treatment, resulting in significant group differences. DAT binding potential changes in these regions correlated negatively with symptom improvement. Findings support that the anxiolytic effects of SSRIs involve psychological factors contingent on dopaminergic neurotransmission while serotonin transporter blockade alone is insufficient for clinical response. Funding Agencies|Swedish Research CouncilSwedish Research CouncilEuropean Commission; Riksbankens Jubileumsfond-the Swedish Foundation for Humanities and Social Sciences; Kjell and Marta Beijer Foundation

[Fifteen patients underwent [Uptake of [High adrenal uptake combined with a low unspecific liver uptake suggests thatClinicalTrials.gov , NCT05361083 Retrospectively registered 29 April 2022. at, https://clinicaltrials.gov/ct2/show/NCT05361083.

Introduction: Early detection of liver fibrosis and monitoring response to treatment crucial for the management of patients are currently not feasible in clinical practice. Platelet derived growth factor receptor beta (PDGER-beta) expression is regarded as a potential biomarker to determine the stages of fibrotic diseases including liver fibrosis. [Ga-68]Ga-BOT5035 comprising a bicyclic peptide was developed for specific targeting of ppGrR-beta overexpressed in pathological fibrosis. The realization of microdosing phase 0 study using [Ga-68]Ga-BOT5035 positron emission tomography required automated good manufacturing practice (GMP) compliant production of [Ga-68]Ga-BOT5035 presented herein. Moreover, the investigation of radiation dosimetry was conducted to ensure possibility of multiple annual examinations for disease monitoring in clinical setup. Methods: The active pharmaceutical ingredient starting material BOT5035 (GMP grade) was provided by BiOrion Technologies BV. The Ga-68-labelling process was developed and automated using synthesis platform (ModularLab PharmTrace, Eckert & Ziegler), disposable cassettes for Ga-68-labelling, and pharmaceutical grade Ge-68/Ga-68 generator (GalliaPharm (R)) purchased from Eckert & Ziegler. Radiolysis sensitive BOT5035 required development and systematic optimization of the labelling synthesis parameters such as time, temperature, precursor concentration, radical scavenger, buffer concentration and pH. The validation process was conducted with regard to the product quality and quantity, as well as production reproducibility. Human organ equivalent doses and total body effective doses were calculated using Organ Level Internal Dose Assessment Code software (OLINDA/EXM 1.1), based on ex vivo organ distribution in Sprague-Dawley rats. Results: The GMP compliant automated production of [Ga-68]Ga-BOT5035 with on-line documentation demonstrated high reproducibility. The time for the labelling synthesis and quality control was approximately 60 min. The non-decay corrected radiochemical yield and radiochemical purity of the radiopharmaceutical were 43.7 +/- 7.6% (n = 3, process validation) and 97.7 +/- 0.4% (n = 3, process validation), respectively. Predefined acceptance criteria were met for the sterility, endotoxins level, radionuclidic purity and residual solvent content. The stability at ambient temperature was controlled for 120 min with approved results. Ex vivo organ distribution data revealed fast blood clearance and washout from most of the organs. The dose-limiting organs were kidney and bone marrow. The total effective dose as limiting parameter would allow for up to 3-4 PET scans per annum. Conclusion: The fully automated and GMP compliant production of [Ga-68]Ga-BOT5035 was developed and thoroughly validated. The radiopharmaceutical was approved by Swedish Medicinal Products Agency and the Ethical Review Authority for the Phase 0 clinical study of the quantitative imaging of liver fibrosis. Human dosimetry calculations extrapolated from animal experiment indicated possibility of 3-4 PET examinations per year.

Aromatase, the enzyme that in the brain converts testosterone and androstenedione to estradiol and estrone, respectively, is a putative key factor in psychoneuroendocrinology. In vivo assessment of aromatase was performed to evaluate tracer kinetic models and optimal scan duration, for quantitative analysis of the aromatase positron emission tomography (PET) ligand [11 C]cetrozole. Anatomical magnetic resonance and 90-min dynamic [11 C]cetrozole PET-CT scans were performed on healthy women. Volume of interest (VOI)-based analyses with a plasma-input function were performed using the single-tissue and two-tissue (2TCM) reversible compartment models and plasma-input Logan analysis. Additionally, the simplified reference tissue model (SRTM), Logan reference tissue model (LRTM), and standardized uptake volume ratio model, with cerebellum as reference region, were evaluated. Parametric images were generated and regionally averaged voxel values were compared with VOI-based analyses of the reference tissue models. The optimal reference model was used for evaluation of a decreased scan duration. Differences between the plasma-input- and reference tissue-based methods and comparisons between scan durations were assessed by linear regression. The [11 C]cetrozole time-activity curves were best described by the 2TCM. SRTM nondisplaceable binding potential (BPND ), with cerebellum as reference region, can be used to estimate [11 C]cetrozole binding and generated robust and quantitatively accurate results for a reduced scan duration of 60 min. Receptor parametric mapping, a basis function implementation of SRTM, as well as LRTM, produced quantitatively accurate parametric images, showing BPND at the voxel level. As PET tracer, [11 C]cetrozole can be employed for relatively short brain scans to measure aromatase binding using a reference tissue-based approach.

Traumatic brain injury (TBI) or repeated sport-related concussions (rSRC) may lead to long-term memory impairment. Diffusion tensor imaging (DTI) is helpful to reveal global white matter damage but may underestimate focal abnormalities. We investigated the distribution of post-injury regional white matter changes after TBI and rSRC. Six patients with moderate/severe TBI, and 12 athletes with rSRC were included ≥6 months post-injury, and 10 (age-matched) healthy controls (HC) were analyzed. The Repeatable Battery for the Assessment of Neuropsychological Status was performed at the time of DTI. Major white matter pathways were tracked using q-space diffeomorphic reconstruction and analyzed for global and regional changes with a controlled false discovery rate. TBI patients displayed multiple classic white matter injuries compared with HC (p < 0.01). At the regional white matter analysis, the left frontal aslant tract, anterior thalamic radiation, and the genu of the corpus callosum displayed focal changes in both groups compared with HC but with different trends. Both TBI and rSRC displayed worse memory performance compared with HC (p < 0.05). While global analysis of DTI-based parameters did not reveal common abnormalities in TBI and rSRC, abnormalities to the fronto-thalamic network were observed in both groups using regional analysis of the white matter pathways. These results may be valuable to tailor individualized rehabilitative approaches for post-injury cognitive impairment in both TBI and rSRC patients.

Introduction: Neutrophils are part of the innate immune system and function as a first line of defense against invading microorganisms. Overactivity of the immune system may result in a devastating immuno-inflammation with extensive damage to tissue leading to organ damage and/or failure. The literature suggests several human diseases in which neutrophil elastase (NE) is postulated to be important in the pathophysiology including inflammatory bowel disease (IBD), chronic obstructive pulmonary disorder (COPD), abdominal aortic aneurysms (AAA), breast and lung cancer, and recently also in Sars-cov-2 virus infection (Covid-19). In particular, the lungs are affected by the destructive power of the protease neutrophil elastase (NE). In this paper, we report the pre-clinical development of a selective and specific positron emission tomography (PET) tracer, [C-11] GW457427, as an in vivo biomarker for the study of NE, now available for human studies. Methods: [C-11]GW457427 was produced by methylation of GW447631 using [C-11]methyl triflate and GMP validated production and quality control methods were developed. Chemical purity was high with no traces of the precursor GW611437 or other uv-absorbing compounds. A method for the determination of intact [C-11] GW457427 in plasma was developed and the binding characteristics were evaluated in vitro and in vivo. An animal model for lung inflammation was used to investigate the specificity and sensitivity of the [C-11]GW457427 tracer for neutrophil elastase (NE) in pulmonary inflammation, verified by blockade using two structurally different elastase inhibitors. Results: [C-11]GW457427 was obtained in approximately 45% radiochemical yield and with a radiochemical purity higher than 98%. Molar activity was in the range 130-360 GBq/mu mol. Binding to NE was shown to be highly specific both in vitro and in vivo and a significantly higher uptake of tracer was found in a lipopolysaccharide mouse model of pulmonary inflammation compared with control animals. The uptake in lung tissue measured as standardized uptake value (SUV) strongly correlated with tissue NE content as measured by ELISA. In vitro studies also showed specific tracer binding in aortic tissue of patients with abdominal aorta aneurysm (AAA). The rate of metabolism in rats was appropriate considering the critical balance between available tracer for binding and requirement for blood clearance with about 40% and 20% intact [C-11]GW457427 in plasma at 5 and 40 min, respectively. Radioactivity was cleared from blood and organs in control animals with mainly hepatobiliary excretion with distribution in the intestines and the urinary bladder; but without retention of the tracer in healthy organs of interests such as the lung, liver, kidneys or in the cardiovascular system. A dosimetry study in rat indicated that the whole-body effective dose was 2.2 mu Sv/MBq with bone marrow as the limiting organ. It is estimated that up to five PET-CT investigations could be performed in humans without exceeding a total dose of 10 mSv. Conclusion: [C-11]GW457427 is a promising in vivo PET-biomarker for NE with high specific binding demonstrated both in vitro and in vivo. A GMP validated production method including quality control has been developed and a microdosing toxicity study performed with no adverse signs. [C-11]GW457427 is currently being evaluated in a First-In-Man PET study.

Primary Objective Traumatic brain injury (TBI) and sports-related concussion (SRC) may result in chronic functional and neuroanatomical changes. We tested the hypothesis that neuroimaging findings (cerebral blood flow (CBF), cortical thickness, and 1H-magnetic resonance (MR) spectroscopy (MRS)) were associated to cognitive function, TBI severity, and sex. Research Design Eleven controls, 12 athletes symptomatic following ≥3SRCs and 6 patients with moderate-severe TBI underwent MR scanning for evaluation of cortical thickness, brain metabolites (MRS), and CBF using pseudo-continuous arterial spin labeling (ASL). Cognitive screening was performed using the RBANS cognitive test battery. Main Outcomes and Results RBANS-index was impaired in both injury groups and correlated with the injury severity, although not with any neuroimaging parameter. Cortical thickness correlated with injury severity (p = 0.02), while neuronal density, using the MRS marker ((NAA+NAAG)/Cr, did not. On multivariate analysis, injury severity (p = 0.0003) and sex (p = 0.002) were associated with CBF. Patients with TBI had decreased gray (p = 0.02) and white matter (p = 0.02) CBF compared to controls. CBF was significantly lower in total gray, white matter and in 16 of the 20 gray matter brain regions in female but not male athletes when compared to female and male controls, respectively. Conclusions Injury severity correlated with CBF, cognitive function, and cortical thickness. CBF also correlated with sex and was reduced in female, not male, athletes. Chronic CBF changes may contribute to the persistent injury mechanisms in TBI and rSRC.

Bone tracers bind to amyloid-containing heart of most patients with ATTR amyloidosis. Amyloid deposits outside the heart are often scarce and bone scintigraphy is increasingly often used to diagnose cardiac involvement. However, the nature of the binding of bone tracers to the heart is not clear.To identify possible calcium deposits in hearts with amyloid, explaining bone tracer binding.Formalin-fixed and paraffin embedded cardiac specimens from three patients with ATTR and one with AL amyloidosis, all with cardiac deposits, were studied. The specimens covered large parts of the heart. Sections were stained immunohistochemically for ATTR deposits and according to von Kóssa for calcifications. The study identified in all hearts, but particularly in the ATTR materials, focal, tight swarms of tiny calcifications. These were sometimes associated with amyloid but found as frequent in areas without such deposits. Autoradiography with [Our study indicates that binding of skeletal probes to amyloid-containing hearts depends on an irregular presence of clouds of very tiny calcifications, which seem not to be directly associated with amyloid fibrils. Therefore, [

Neutrophils are part of the innate immune system and function as a first line of defense against invading microorganisms. Overactivity of the immune system may result in a devastating immuno-inflammation with extensive damage to tissue leading to organ damage and/or failure. The literature suggests several human diseases in which neutrophil elastase (NE) is postulated to be important in the pathophysiology including inflammatory bowel disease (IBD), chronic obstructive pulmonary disorder (COPD), abdominal aortic aneurysms (AAA), breast and lung cancer, and recently also in Sars-cov-2 virus infection (Covid-19). In particular, the lungs are affected by the destructive power of the protease neutrophil elastase (NE). In this paper, we report the pre-clinical development of a selective and specific positron emission tomography (PET) tracer, [[[[

A new method for the fluorine-18 labelling of trifluoromethyl ketones has been developed. This method is based on the conversion of a-COCF

Pharmacological inhibition of phosphodiesterase 10A (PDE10A) is being investigated as a treatment option in schizophrenia. PDE10A acts postsynaptically on striatal dopamine signaling by regulating neuronal excitability through its inhibition of cyclic adenosine monophosphate (cAMP), and we recently found it to be reduced in schizophrenia compared to controls. Here, this finding of reduced PDE10A in schizophrenia was followed up in the same sample to investigate the effect of reduced striatal PDE10A on the neural and behavioral function of striatal and downstream basal ganglia regions. A positron emission tomography (PET) scan with the PDE10A ligand [11C]Lu AE92686 was performed, followed by a 6 min resting-state magnetic resonance imaging (MRI) scan in ten patients with schizophrenia. To assess the relationship between striatal function and neurophysiological and behavioral functioning, salience processing was assessed using a mismatch negativity paradigm, an auditory event-related electroencephalographic measure, episodic memory was assessed using the Rey auditory verbal learning test (RAVLT) and executive functioning using trail-making test B. Reduced striatal PDE10A was associated with increased amplitude of low-frequency fluctuations (ALFF) within the putamen and substantia nigra, respectively. Higher ALFF in the substantia nigra, in turn, was associated with lower episodic memory performance. The findings are in line with a role for PDE10A in striatal functioning, and suggest that reduced striatal PDE10A may contribute to cognitive symptoms in schizophrenia.

Geminal 18F-oxyfluorination of diazoketones was performed in the presence of rhodium mediators. The reactions were performed using a hypervalent iodine-based [18F]fluoro-benziodoxole reagent. By this methodology various α-[18F]fluoro ethers were obtained in high radiochemical yield (up to 98%) and molar activity (216 GBq μmol-1).

Introduction: The Glucagon Like Peptide-1 receptor (GLP1R) is a gut hormone receptor, intricately linked to regulation of blood glucose homeostasis via several mechanisms. It is an established and emergent drug target in metabolic disease. Positron Emission Tomography (PET) radioligand 68Ga-DO3A-VS-Exendin4 (68Ga-Exendin4) has the potential to enable longitudinal studies of the GLP1R in human pancreas. Methods:68Ga-Exendin4 PET/CT examinations were acquired in overweight to obese individuals with type 2 diabetes (T2D) (n = 13) as part of a larger target engagement study (NCT03350191). A scanning protocol was developed to optimize reproducibility (target amount of 0.5 MBq/kg, corresponding to

The prospects for using carbon-11 labelled compounds in molecular imaging has improved with the development of diverse synthesis methods, including C-11-carbonylations and refined techniques to handle [C-11]carbon monoxide at a nanomole scale. Facilitating biological research and molecular imaging was the driving force when [C-11]carbon monoxide was used in the first in vivo application with carbon-11 in human (1945) and when [C-11]carbon monoxide was used for the first time as a chemical reagent in the synthesis of [C-11]phosgene (1978). This review examines a rich plethora of labelled compounds synthesized from [C-11]carbon monoxide, their chemistry and use in molecular imaging. While the strong development of the C-11-carbonylation chemistry has expanded the carbon-11 domain considerably, it could be argued that the number of C-11-carbonyl compounds entering biological investigations should be higher. The reason for this may partly be the lack of commercially available synthesis instruments designed for C-11-carbonylations. But as this review shows, novel and greatly simplified methods to handle [C-11]carbon monoxide have been developed. The next important challenge is to make full use of these technologies and synthesis methods in PET research. When there is a PET-tracer that meets a more general need, the incentive to implement C-11-carbonylation protocols will increase.

Graphical abstract, Highlights • Traumatic brain injury (TBI) leads to axonal injury and an inflammatory response. • Repeated sports-related concussions (rSRC) are linked to neurodegeneration. • We studied tau aggregation and neuroinflammation in rSRC and TBI using PET/MRI. • In young rSRC and TBI patients, tau aggregation and neuroinflammation was increased. • PET useful when studying the long-term consequences of rSRC and TBI., Traumatic brain injury (TBI) and repeated sports-related concussions (rSRCs) are associated with an increased risk for neurodegeneration. Autopsy findings of selected cohorts of long-term TBI survivors and rSRC athletes reveal increased tau aggregation and a persistent neuroinflammation. To assess in vivo tau aggregation and neuroinflammation in young adult TBI and rSRC cohorts, we evaluated 9 healthy controls (mean age 26 ± 5 years; 4 males, 5 females), 12 symptomatic athletes (26 ± 7 years; 6 males, 6 females) attaining ≥3 previous SRCs, and 6 moderate-to severe TBI patients (27 ± 7 years; 4 males, 2 females) in a combined positron emission tomography (PET)/magnetic resonance (MR) scanner ≥6 months post-injury. Dual PET tracers, [18F]THK5317 for tau aggregation and [11C]PK11195 for neuroinflammation/microglial activation, were investigated on the same day. The Repeated Battery Assessment of Neurological Status (RBANS) scores, used for cognitive evaluation, were lower in both the rSRC and TBI groups (p

Serotonin and dopamine are putatively involved in the etiology and treatment of anxiety disorders, but positron emission tomography (PET) studies probing the two neurotransmitters in the same individuals are lacking. The aim of this multitracer PET study was to evaluate the regional expression and co-expression of the transporter proteins for serotonin (SERT) and dopamine (DAT) in patients with social anxiety disorder (SAD). Voxel-wise binding potentials (BPND) for SERT and DAT were determined in 27 patients with SAD and 43 age- and sex-matched healthy controls, using the radioligands [11C]DASB (3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile) and [11C]PE2I (N-(3-iodopro-2E-enyl)-2beta-carbomethoxy-3beta-(4'-methylphenyl)nortropane). Results showed that, within transmitter systems, SAD patients exhibited higher SERT binding in the nucleus accumbens while DAT availability in the amygdala, hippocampus, and putamen correlated positively with symptom severity. At a more lenient statistical threshold, SERT and DAT BPND were also higher in other striatal and limbic regions in patients, and correlated with symptom severity, whereas no brain region showed higher binding in healthy controls. Moreover, SERT/DAT co-expression was significantly higher in SAD patients in the amygdala, nucleus accumbens, caudate, putamen, and posterior ventral thalamus, while lower co-expression was noted in the dorsomedial thalamus. Follow-up logistic regression analysis confirmed that SAD diagnosis was significantly predicted by the statistical interaction between SERT and DAT availability, in the amygdala, putamen, and dorsomedial thalamus. Thus, SAD was associated with mainly increased expression and co-expression of the transporters for serotonin and dopamine in fear and reward-related brain regions. Resultant monoamine dysregulation may underlie SAD symptomatology and constitute a target for treatment.

There is an unmet medical need for non-invasive, sensitive, and quantitative methods for the assessment of fibrosis. Herein, an improved collagelin analogue labelled with gallium-68 for use with positron emission tomography (PET) is presented. A cyclic peptide, c[CPGRVNleHGLHLGDDEGPC], was synthesized by solid-phase peptide synthesis, conjugated to 2-(4,7-bis(2-(tert-butoxy)-2-oxoethyl)-1,4,7-triazonan-1-yl)acetic acid, and labelled with gallium-68. High performance liquid chromatography (HPLC) was used for the quality and stability assessment of the collagelin analogue. Non-specific organ distribution, blood clearance, and excretion rates were investigated in healthy mice and rats using ex vivo organ distribution analysis and dynamic in vivo PET/CT. Mice with carbon tetrachloride (CCl4) induced liver fibrosis were used for the investigation of specific binding via in vitro frozen section autoradiography, ex vivo organ distribution, and in vivo PET/CT. A non-decay corrected radiochemical yield (48 ± 6%) of [68Ga]Ga-NOTA-PEG2-c[CPGRVNleHGLHLGDDEGPC] ([68Ga]Ga-NO2A-[Nle13]-Col) with a radiochemical purity of 98 ± 2% was achieved without radical scavengers. The 68Ga-labelling was regioselective and stable at ambient temperature for at least 3 h. The autoradiography of the cryosections of fibrotic mouse liver tissue demonstrated a distinct heterogeneous radioactivity uptake that correlated with the fibrosis scores estimated after Sirius Red staining. The blood clearance and tissue washout from the [68Ga]Ga-NO2A-[Nle13]-Col was fast in both normal and diseased mice. Dosimetry investigation in rats indicated the possibility for 4–5 PET/CT examinations per year. Radiolytic stability of the collagelin analogue was achieved by the substitution of methionine with norleucine amino acid residue without a deterioration of its binding capability. [68Ga]Ga-NO2A-[Nle13]-Col demonstrated a safe dosimetry profile suitable for repeated scanning. Title in Web of Science: Improved Radiolytic Stability of a Ga-68-labelled Collagelin Analogue for the Imaging of Fibrosis

The Gamma-aminobutyric acid (GABA) and glutamate (Glu) neurotransmitter systems are implicated in depression. While previous studies found reduced GABA levels, and a tendency towards reduced Glu, using proton (H-1) magnetic resonance spectroscopy (H-1-MRS), little is known about GABA(A) receptor availability in depression. Here, the aim was to characterize GABA and Glu-levels in dorsal anterior cingulate cortex (dACC), whole-brain GABA(A) availability, and their relationship in patients with depression compared to healthy controls. Forty-two patients and 45 controls underwent H-1-MRS using a MEGA-PRESS sequence to quantify dACC GABA+ and Glu (contrasted against creatine [Cr]). Immediately preceding the H-1-MRS, a subsample of 28 patients and 15 controls underwent positron emission tomography (PET) with [C-11]Flumazenil to assess whole-brain GABA(A) receptor availability. There were no differences in dACC GABA+/Cr or Glu/Cr ratios between patients and controls. The same was true for whole-brain GABA(A) receptor availability. However, there was a significant negative relationship between GABA+/Cr ratio and receptor availability in ACC, in a whole-brain voxel-wise analysis across patients and controls, controlling for group or depressive symptoms. This relatively large study did not support the GABA-deficit hypothesis in depression, but shed light on GABA-system functioning, suggesting a balance between neurotransmitter concentration and receptor availability in dACC.

Introduction: [68Ga]Ga-DO3A-VS-Cys40-Tuna-2 (previously published as [68Ga]Ga-DO3A-VS-Cys40-S01-GCG) has shown high-affinity specific binding to the glucagon receptor (GCGR) in vitro and in vivo in rats and non-human primates in our previous studies, confirming the suitability of the tracer for drug development applications in humans. The manufacturing process of [68Ga]Ga-DO3A-VS-Cys40-Tuna-2 was automated for clinical use to meet the radiation safety and good manufacturing practice (GMP) requirements. Methods: The automated synthesis platform (Modular-Lab PharmTrace, Eckert &amp, Ziegler, Eurotope, Germany), disposable cassettes for 68Ga-labeling, and pharmaceutical-grade 68Ge/68Ga generator (GalliaPharm&reg, ) used in the study were purchased from Eckert &amp, Ziegler. The parameters such as time, temperature, precursor concentration, radical scavenger, buffer concentration, and pH, as well as product purification step, were investigated and optimized. Process optimization was conducted with regard to product quality and quantity, as well as process reproducibility. The active pharmaceutical ingredient starting material DO3A-VS-Cys40-Tuna-2 (GMP-grade) was provided by Sanofi Aventis. Results: The reproducible and GMP-compliant automated production of [68Ga]Ga-DO3A-VS-Cys40-Tuna-2 with on-line documentation was developed. The non-decay-corrected radiochemical yield was 45.2 &plusmn, 2.5% (n = 3, process validation) at the end of the synthesis with a labeling synthesis duration of 38 min and a quality controlincluding release procedure of 20 min. The radiochemical purity of the product was 98.9 &plusmn, 0.6% (n = 17) with the total amount of the peptide in the preparation of 48 &plusmn, 2 &micro, g (n = 3, process validation). Radionuclidic purity, sterility, endotoxin content, residual solvent content, and sterile filter integrity tests met the acceptance criteria. The product was stable at ambient temperature for at least 2 h. Conclusion: The fully automated GMP-compliant manufacturing process was developed and thoroughly validated. The resulting [68Ga]Ga-DO3A-VS-Cys40-Tuna-2 was used in a clinical study for accurate quantification of GCGR occupancy by a dual anti-diabetic drug in vivo in humans.

Early detection of liver fibrosis and monitoring response to treatment crucial for the management of patients are currently not feasible in clinical practice. Platelet derived growth factor receptor β (PDGFR-β) expression is regarded as a potential biomarker to determine the stages of fibrotic diseases including liver fibrosis. [The active pharmaceutical ingredient starting material BOT5035 (GMP grade) was provided by BiOrion Technologies BV. TheThe GMP compliant automated production of [The fully automated and GMP compliant production of [

Despite the importance of the glucagon receptor (GCGR) in disease and in pharmaceutical drug development, there is a lack of specific and sensitive biomarkers of its activation in humans. The PET radioligand

OBJECTIVES: This dual-site study evaluated the diagnostic accuracy of the method.BACKGROUND: Pittsburgh compound ([11C]PIB) positron emission tomography (PIB-PET) has shown promise as a specific and noninvasive method for the diagnosis of cardiac amyloidosis (CA).METHODS: The study had 2 parts. In the initial study, 51 subjects were included, 36 patients with known CA and increased wall thickness (15 immunoglobulin light chain [AL] and 21 transthyretin [ATTR] amyloidosis) and 15 control patients (7 were nonamyloid hypertrophic and 8 healthy volunteers). Subjects underwent PIB-PET and echocardiography. Sensitivity and specificity of PIB-PET were established for 2 simple semiquantitative approaches, standardized uptake value ratio (SUVR) and retention index (RI). The second part of the study included 11 amyloidosis patients (5 AL and 6 hereditary ATTR) without increased wall thickness to which the optimal cutoff values of SUVR (>1.09) and RI (>0.037 min-1) were applied prospectively.RESULTS: The diagnostic accuracy of visual inspection of [11C]PIB uptake was 100% in discriminating CA patients with increased wall thickness from controls. Semiquantitative [11C]PIB uptake discriminated CA from controls with a 94% (95% confidence interval [CI]: 80% to 99%) sensitivity for both SUVR and RI and specificity of 93% (95% CI: 66% to 100%) for SUVR and 100% (95% CI: 75% to 100%) for RI. [11C]PIB uptake was significantly higher in AL-CA than in ATTR-CA patients (p < 0.001) and discriminated AL-CA from controls with 100% (95% CI: 88% to 100%) accuracy for both the semiquantitative measures. In the prospective group without increased wall thickness, RI was elevated compared to controls (p = 0.001) and 5 of 11 subjects were evaluated as [11C]PIB PET positive.CONCLUSIONS: In a dual-center setting, [11C]PIB PET was highly accurate in detecting cardiac involvement in the main amyloid subtypes, with 100% accuracy in AL amyloidosis. A proportion of amyloidosis patients without known cardiac involvement were [11C]PIB PET positive, indicating that the method may detect early stages of CA.

The prospects for using carbon-11 labelled compounds in molecular imaging has improved with the development of diverse synthesis methods, including