Dorsal prefrontal cortical serotonin 2A receptor binding indices are differentially related to individual scores on harm avoidance.

Although the serotonergic system has been implicated in healthy as well as in pathological emotional states, knowledge about its involvement in personality is limited. Earlier research on this topic suggests that post-synaptic 5-HT2A receptors could be involved in particular in frontal cortical areas. In drug-naïve healthy individuals, we examined the relationship between these 5-HT2A receptors and the temperament dimension harm avoidance (HA) using 123I-5-I-R91150 single photon emission computed tomography (SPECT).

Stress sensitive healthy females show less left amygdala activation in response to withdrawal-related visual stimuli under passive viewing conditions.

The amygdalae are key players in the processing of a variety of emotional stimuli. Especially aversive visual stimuli have been reported to attract attention and activate the amygdalae. However, as it has been argued that passively viewing withdrawal-related images could attenuate instead of activate amygdalae neuronal responses, its role under passive viewing conditions remains unclear.

The influence of emotional priming on the neural substrates of memory: a prospective fMRI study using portrait art stimuli.

Events coupled with an emotional context seem to be better retained than non-emotional events. The aim of our study was to investigate whether an emotional context could influence the neural substrates of memory associations with novel portrait art stimuli. In the current prospective fMRI study, we have investigated for one specific visual art form (modern artistic portraits with a high degree of abstraction) whether memory is influenced by priming with emotional facial pictures.

Inhibition of firefly luciferase by general anesthetics: effect on in vitro and in vivo bioluminescence imaging.

Unlabelled: Bioluminescence imaging is routinely performed in anesthetized mice. Often isoflurane anesthesia is used because of its ease of use and fast induction/recovery. However, general anesthetics have been described as important inhibitors of the luciferase enzyme reaction.

Is treatment-resistance in unipolar melancholic depression characterized by decreased serotonin₂A receptors in the dorsal prefrontal - anterior cingulate cortex?

Objectives: Quite a number of patients diagnosed with major depression are resistant to several well carried-out psychopharmacological interventions. It remains unclear as to how the serotonergic system is implicated in the phenomenon of treatment-resistance.

Methods: We examined the involvement of post-synaptic 5-HT(2A) receptors in the pathophysiology of treatment-resistance in unipolar melancholic major depression with (123)I-5-I-R91150 SPECT.

The impact of HF-rTMS treatment on serotonin(2A) receptors in unipolar melancholic depression.

Background: Currently, the underlying neurobiological mechanism as to how repetitive transcranial magnetic stimulation (rTMS) can alter depressive states remains unclear. Animal data suggest that its influence could occur at the neurotransmitter level, such as modulation of the serotonin system.

Methods: Twenty-one antidepressant-free medication-resistant unipolar depressed patients, and 21 age- and gender-matched healthy subjects were studied.

The effect of one left-sided dorsolateral prefrontal cortical HF-rTMS session on emotional brain processes in women.

Although repetitive Transcranial Magnetic Stimulation (rTMS) is frequently used to examine emotional changes in healthy volunteers, it remains largely unknown how rTMS is able to influence emotion.We carried out a sham-controlled single-blind crossover study using fMRI, we examined in 20 right-handed healthy female volunteers whether a single high frequency (HF)-rTMS session applied to the left dorsolateral prefrontal cortex (DLPFC) could influence emotional processing while focussing on blocks of positively and negatively valenced baby faces. A single HF-rTMS session selectively influenced the processing of positively and negatively valenced baby faces.

Localization, mechanism and reduction of renal retention of technetium-99m labeled epidermal growth factor receptor-specific nanobody in mice.

Background: Nanobodies are single-domain antigen binding fragments derived from functional heavy-chain antibodies elicited in Camelidae. They are powerful probes for radioimmunoimaging, but their renal uptake is relatively high. In this study we have evaluated the role of megalin on the renal uptake of anti-EGFR (99m)Tc-7C12 nanobody and the potency of gelofusine and/or lysine to reduce renal uptake of (99m)Tc-7C12.

Improved quantification in multiple-pinhole SPECT by anatomy-based reconstruction using microCT information.

Purpose: The aim of this study was to evaluate the potential of anatomy-based reconstruction, using microCT information, to improve quantitative accuracy in multiple-pinhole SPECT.

Methods: Multiple-pinhole SPECT and microCT images were acquired with the Micro Deluxe Phantom using both hot and cold rod inserts. The phantoms were filled with 3.

Evaluation of the radiation dose in micro-CT with optimization of the scan protocol.

Introduction: Micro-CT provides non-invasive anatomic evaluation of small animals. Serial micro-CT measurements are, however, hampered by the severity of ionizing radiation doses cumulating over the total period of follow-up. The dose levels may be sufficient to influence experimental outcomes such as animal survival or tumor growth.

In vitro analysis and in vivo tumor targeting of a humanized, grafted nanobody in mice using pinhole SPECT/micro-CT.

Unlabelled: Nanobodies are a novel type of immunoglobulinlike, antigen-binding protein with beneficial pharmacologic and pharmacokinetic properties that are ideally suited to targeting cellular antigens for molecular imaging or therapeutic purposes. However, because of their camelid, nonhuman origin, the possible immunogenicity of Nanobodies when used in the clinic is a concern. Here we present a new strategy to quickly generate humanized Nanobodies for molecular imaging purposes.

Passively viewing negatively valenced baby faces attenuates left amygdala activity in healthy females scoring high on 'Harm Avoidance'.

The amygdalae play an important role in the evaluation and processing of emotionally salient visual stimuli. However, individual differences in personality traits, such as Harm Avoidance (HA), have been reported to influence emotional amygdalae responses. To trigger strong approach and withdrawal-related emotions in 'never depressed' young female subjects under fMRI, we presented them with blocks of happy 'healthy' baby faces and baby faces disfigured by severe dermatological conditions and we integrated the temperament dimension HA into our analysis.

Preliminary in vivo evaluation of [131I]-2-iodo-D-phenylalanine as a potential radionuclide therapeutic agent in R1M-fluc rhabdomyosarcoma tumor-bearing NuNu mice using bioluminescent imaging.

Background: Carrier-added [(123)I]-2-iodo-D-phenylalanine (CA [(123)I]-2-I-D-Phe) was previously found to have a preferential retention in tumors with a high tumor background contrast in animal models. A previous human dosimetry study demonstrated a favorable biodistribution and radiation burden in human subjects.

Aim: The aim of this study was to investigate the potential of CA [(131)I]-2-I-D-Phe as an agent for radionuclide therapy.

Plasma protein binding of luciferase substrates influences sensitivity and accuracy of bioluminescence imaging.

Introduction: Potential confounding factors in bioluminescence imaging (BLI)-quantification need to be identified to improve its accuracy and repeatability.

Purpose: The aim of this study was to study the degree to which plasma protein binding of BLI substrates influences signal intensity and quantification, both in vitro and in vivo.

Procedures: Protein binding was assessed using ultrafiltration and spectrophotometry.

Effect of high-intensity ultrasound-targeted microbubble destruction on perfusion and function of the rat heart assessed by pinhole-gated SPECT.

Although ultrasound-targeted microbubble destruction (UTMD) has been shown to induce bioeffects, UTMD is still desirable for therapeutic applications. Therefore, we studied the effects of UTMD on perfusion and function of the rat heart, assessed by (99m)Tc-MIBI pinhole-gated SPECT (Ph-gSPECT) compared with biomarker release and histopathology. Fifty-two male Wistar rats were studied.

HF-rTMS treatment in medication-resistant melancholic depression: results from 18FDG-PET brain imaging.

Introduction: High frequency repetitive transcranial magnetic stimulation (HF-rTMS) of the left dorsolateral prefrontal cortex (DLPFC) might be a promising strategy to treat depression, but not all patients show a positive outcome.

Objective: In this open study, we evaluate whether a favorable HF-rTMS treatment outcome could be predicted by baseline prefrontal brain glucose metabolism (CMRglc), measured by 18fluorodeoxyglucose positron emission tomography (18FDG-PET).

Methods: A sample of 21 antidepressant-free, treatment-resistant depression (TRD) patients of the melancholic subtype received 10 sessions of HF-rTMS delivered on the left DLPFC.

Tracheobronchomalacia incidentally detected on Tc-99m ventilation/perfusion SPECT.

A Tc-99m Technegas MAA-SPECT was performed on an 81-year-old woman to exclude pulmonary embolism. It showed hypoperfusion and practically absent ventilation of the entire left lung, suggesting a left-sided centrally localized airway obstruction or compression with secondary hypoxic vasoconstriction. Subsequent bronchoscopy and CT scan detected tracheobronchomalacia with significant narrowing of the left bronchus.

Amygdala responses to positively and negatively valenced baby faces in healthy female volunteers: influences of individual differences in harm avoidance.

Research regarding the lateralization of processing emotional visual stimuli suggests various roles for affective information-processing by the amygdalae. However, individual differences seem to influence outcome results. In this study we re-investigate this question, paying special attention to the salient nature of the mood inducing stimuli.

Regional quantitative analysis of small animal myocardial sympathetic innervation and initial application in streptozotocin induced diabetes.

Background: In several disease models it is known that heterogeneous dysinnervation occurs in the sympathetic nervous system. We therefore adapted the (123)I-MIBG imaging procedure in small animals to allow quantification of both global and regional uptake and wash-out rate using high specific activity (123)I-MIBG in the myocardium of rats. After evaluation of the image procedure in normal animals, we then applied our imaging protocol to visualize the regional dysinnervation in cardiac autonomic neuropathy occurring in streptozotocin-induced diabetes.

Dose dependency and reversibility of serotonin-induced valvular heart disease in rats.

Serotonergic drugs may lead to valvular heart disease in humans and more recently also in rats. Although clinical data suggest that dose dependency and reversibility after drug cessation might occur, proof of this is lacking. For that purpose, a total of 106 rats were prospectively enrolled: 22 control animals and 7 groups of 12 rats that received daily subcutaneous serotonin injections (5, 10, 20, 30, 40, 50 and 60 mg/kg respectively) for 12 weeks.

Improved quantification in single-pinhole and multiple-pinhole SPECT using micro-CT information.

Purpose: The purpose of this study was to demonstrate the feasibility of accurate quantification in pinhole SPECT using micro-CT information.

Methods: Pinhole SPECT scans were performed using a clinical dual-head gamma camera. Each pinhole SPECT scan was followed by a micro-CT acquisition.

Using 3D-MRI to localize the dorsolateral prefrontal cortex in TMS research.

Transcranial magnetic stimulation (TMS) is currently used as a non-invasive treatment for depression. In most clinical trials, the left dorsolateral prefrontal cortex (DLPFC) has been selected as the target site for TMS treatment and this region is commonly determined by a "standard procedure", using a fixed position with respect to the motor cortex. In this study, to evaluate the relevance of using individual anatomical data during coil positioning, we used a more individualized localization method, based on three-dimensional magnetic resonance imaging of the head (3D-MRI).

Echocardiographic and histological assessment of age-related valvular changes in normal rats.

Aging is associated with morphologic and functional alterations of the rat's left ventricle. However, the time-course of valvular function and morphology in normal aging rats has not yet been studied. For this purpose, 30 male Wistar rats (318 +/- 5g, 10 weeks old) underwent serial echocardiograms for 58 weeks under sodium pentobarbital 50 mg/kg IP anesthetization followed by necropsy.

Time-course of contrast enhancement in spleen and liver with Exia 160, Fenestra LC, and VC.

Objective: The purpose of this study was to compare the time-course of contrast-enhancement in spleen and liver using Exia 160 in comparison with Fenestra LC and VC in healthy mice.

Procedures: Healthy C57bl/6 mice were used in this study. Fenestra LC and VC was administered intravenously at a dose of 0.