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Background: Although studies have indicated that the frontal lobe plays an important role in performance on the Wisconsin Card Sorting Test (WCST) and that basal ganglia play a specific role in frontal lobe function, the role of striatal dopamine (DA) activity in performance on the WCST remains unclear. Methods: We assessed the relation between the availability of striatal dopamine transporters (DATs) and performance on the WCST as a measure of executive function in healthy individuals. We approximated the availability of DATs in 53 healthy volunteers aged 19-61 years by use of single photon emission computed tomography with technetium-99m ([sup.99m]Tc)-TRODAT-1 as the ligand. The WCST was administered to all participants. Results: The availability of DAT was significantly negatively correlated with perseverative errors on the WCST, both before and after adjustment for body mass index ([r.sub.before] = -0.39, p = 0.004; [r.sub.after] = -0.39, p = 0.005). Limitations: This was an association study; thus, a causal relation between DAT availability and performance cannot be confirmed. Conclusion: Our results suggest that striatal DAT availability may play a role in executive function as measured by the WCST., Introduction The Wisconsin Card Sorting Test (WCST) is an important neuropsychological test that is generally regarded as a prototype abstract reasoning task. The test is mainly reliant on frontal lobe [...]

Neuropsychiatric disorders are becoming a major socioeconomic burden to modern society. In recent years, a dramatic expansion of tools has facilitated the study of the molecular basis of neuropsychiatric disorders. Molecular imaging has enabled the noninvasive characterization and quantification of biological processes at the cellular, tissue, and organism levels in intact living subjects. This technology has revolutionized the practice of medicine and has become critical to quality health care. New advances in research on molecular imaging hold promise for personalized medicine in neuropsychiatric disorders, with adjusted therapeutic doses, predictable responses, reduced adverse drug reactions, early diagnosis, and personal health planning. In this paper, we discuss the development of radiotracers for imaging dopaminergic, serotonergic, and noradrenergic systems and β-amyloid plaques. We will underline the role of molecular imaging technologies in various neuropsychiatric disorders, describe their unique strengths and limitations, and suggest future directions in the diagnosis and management of neuropsychiatric disorders., 1. Introduction Modern neuroimaging offers tremendous opportunities for gaining insights into the molecular basis of neuropsychiatric disorders. Molecular imaging shows how specific tissues are functioning. This contrasts with conventional diagnostic [...]

Radiolabeled annexin V (ANV) has been widely used for imaging cell apoptosis. Recently, a novel ANV-Kunitz-type protease inhibitor fusion protein, ANV-6L15, was found to be a promising probe for improved apoptosis detection based on its higher affinity to phosphatidylserine (PS) compared to native ANV. The present paper investigates the feasibility of apoptosis detection using radioiodinated ANV-6L15. Native ANV and ANV-6L15 were labeled with iodine-123 andiodine-125 using Iodogen method. The binding between the radioiodinated proteins and erythrocyte ghosts or chemical-induced apoptotic cells was examined. ANV-6L15 can be radioiodinated with high yield (40%-60%) and excellent radiochemical purity (>95%). [sup.123]I-ANV-6L15 exhibited a higher binding ratio to erythrocyte ghosts and apoptotic cells compared to [sup.123]I-ANV. The biodistribution of [sup.123]I-ANV-6L15 in mice was also characterized. [sup.123]I-ANV-6L15 was rapidly cleared from the blood. High uptake in the liver and the kidneys may limit the evaluation of apoptosis in abdominal regions. Our data suggest that radiolabled ANV-6L15 may be a better scintigraphic tracer than native ANV for apoptosis detection., 1. Introduction Apoptosis (programmed cell death) plays an important role in the maintenance of physiological homeostasis as well as in the pathogenesis of a number of disorders including cerebral and [...]

Technetium-99m ethyl cysteinate dimer (Tc-99m-ECD) is an essential imaging agent used in evaluating the regional cerebral blood flow in patients with cerebrovascular diseases. Determination of active pharmaceutical ingredient, that is, L-Cysteine, N, N'-1,2-ethanediylbis-, diethyl ester, dihydrochloride (ECD) in ECD Kit is a relevant requirement for the pharmaceutical quality control in processes of mass fabrication. We here presented a direct solid sample determination method of ECD in ECD Kit without sample dissolution to avoid the rapid degradation of ECD. An elemental analyzer equipped with a nondispersive infrared detector and a calibration curve of coal standard was used for the quantitation of sulfur in ECD Kit. No significant matrix effect was found. The peak area of coal standard against the amount of sulfur was linear over the range of 0.03-0.10 mg, with a correlation coefficient (r) of 0.9993. Method validation parameters were achieved to demonstrate the potential of this method., 1. Introduction To date, technetium-99m ethyl cysteinate dimer (Tc-99m-ECD or bicisate) is one of the most essential single-photon emission-computed tomography (SPECT) imaging agents in hospitals. According to the practice guidelines [...]

Rationale and objective: Serotonin is one of the key neuromodulators involved in fundamental cerebral functions and behaviors. Previous study has demonstrated that somatization symptoms are probably associated with central serotonergic circuits, which are implicated in anxiety and nociception regulation. This study aims to examine the correlation between somatization subscale score and serotonin transporter (SERT) availability in healthy volunteers. Methods: Sixty-four healthy participants, 26 males and 38 females, were enrolled from the community and were administered the single somatization subscale of the Chinese symptom checklist 90 revised (SCL90-R). Single photon emission computed tomography with [I] 2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine was also performed to examine SERT availability. Results: The somatization scores were negatively correlated with SERT availability (Spearman's ρ = −0.35, p = 0.005), particularly in males (Spearman's ρ = −0.54, p = 0.004). Conclusion: This result reconfirmed the correlation between central serotonergic activity and the intensity of somatization symptoms, even in healthy participants. However, a gender difference exists in this correlation. [ABSTRACT FROM AUTHOR]