Synthesis and initial evaluation of radioiodine-labelled deuterated tropane derivatives targeting dopamine transporter.

The dopamine transporter (DAT) is closely related to a variety of neurological disorders including Parkinson's disease (PD) and other neurodegenerative diseases. In vivo imaging of DAT with radio-labelled tracers has become a powerful technique in related disorders. The radioiodine-labelled tropane derivative [123I]FP-CIT ([123I]1a) is widely used in clinical single photon emission computed tomography (SPECT) imaging as a DAT imaging agent. To develop more metabolically stable DAT radioligands for accurate imaging, this work compared two novel deuterated tropane derivatives ([131I]1c-d) with non-deuterated tropane derivatives ([131I]1a-b). [131I]1a-d were obtained in high radiochemical purity (RCP) above 99 % with molar activities of 7.0-10.0 GBq/µmol. The [131I]1a and [131I]1c exhibited relatively higher affinity to DAT (Ki: 2.0-3.12 nM) than [131I]1b and [131I]1d. Biodistribution results showed that [131I]1c consistently exhibited a higher ratio of the target to non-target (striatum/cerebellum) than [131I]1a. Furthermore, metabolism studies indicated that the in vivo metabolic stability of [131I]1c was superior to that of [131I]1a. Ex vivo autoradiography showed that [131I]1c selectively localized on DAT-rich striatal regions and the specific signal could be blocked by DAT inhibitor. These results indicated that [131I]1c might be a potential probe for DAT SPECT imaging in the brain.

Elucidating the molecular mechanisms of ozone therapy for neuropathic pain management by integrated transcriptomic and metabolomic approach.

Introduction: Neuropathic pain remains a prevalent and challenging condition to treat, with current therapies often providing inadequate relief. Ozone therapy has emerged as a promising treatment option; however, its mechanisms of action in neuropathic pain remain poorly understood. Methods: In this study, we investigated the effects of ozone treatment on gene expression and metabolite levels in the brainstem and hypothalamus of a rat model, using a combined transcriptomic and metabolomic approach. Results: Our findings revealed significant alterations in key genes, including DCST1 and AIF1L, and metabolites such as Aconitic acid, L-Glutamic acid, UDP-glucose, and Tyrosine. These changes suggest a complex interplay of molecular pathways and region-specific mechanisms underlying the analgesic effects of ozone therapy. Discussion: Our study provides insights into the molecular targets of ozone treatment for neuropathic pain, laying the groundwork for future research on validating these targets and developing novel therapeutic strategies.

Visible-Light Photocatalytic Synthesis of Difluoromethylated Selenides from Selenosulfonates through a Radical Process.

A photocatalytic synthesis of difluoromethylated selenides from selenosulfonates is described here. Bench-stable difluoromethyl phosphonium salt [Ph3PCF2H]Br reacts smoothly with selenosulfonates to give a series of functionalized difluoromethylated selenides in moderate to good yields via a radical process. This protocol is free of a stoichiometric base and reductant, has tolerance of functional groups, and has successful late-stage modification of bioactive molecules, which provides facile access to molecules of pharmaceutical relevance.

Deuterated [18F]fluoroethyl tropane analogs as dopamine transporter probes: Synthesis and biological evaluation.

INTRODUCTION: The dopamine transporter (DAT) is vitally correlated with Parkinson's disease (PD) and other neurodegenerative diseases. Non-invasive imaging of DAT contributes to early diagnosis and monitoring of related diseases. Recently, we reported a deuterated [18F]fluoroethyl tropane analogue [18F]FECNT-d4 as a potential DAT PET imaging agent. The objective of this work was to extend the investigation by comparing four deuterated [18F]fluoroethyl tropane derivatives ([18F]2a-d) to develop metabolically stable DAT radioligands. METHODS: Four fluoroethyl substituted phenyl-tropane compounds 1a-d and deuterated compounds 2a-d were synthesized and their IC50 values to DAT were evaluated. The [18F]fluoroethyl ligands [18F]1a-d and [18F]2a-d were obtained from corresponding labeling precursors by one-step radio-labeling reactions and investigated in terms of lipophilicity and in vitro binding affinity studies. [18F]1d and [18F]2d were then selected for further evaluations by in vivo metabolism study, biodistribution, ex vivo autoradiography, and microPET imaging studies. RESULTS: [18F]1a-d and [18F]2a-d were obtained in radiochemical yield of 11-32 % with molar activities of 28-54 GBq/µmol. The 1d and 2d exhibited relatively high affinity to DAT (IC50: 1.9-2.1 nM). Ex vivo autoradiography and microPET studies showed that [18F]2d selectively localized on DAT-rich striatal regions and the specific signal could be blocked by DAT inhibitor. Biodistribution results showed that [18F]2d consistently exhibited a higher ratio of the target to non-target (striatum/cerebellum) than [18F]1d. Furthermore, metabolism study indicated that the in vivo metabolic stability of [18F]2d was superior to that of [18F]1d. CONCLUSION: Our findings suggested that the deuterated compound [18F]2d might be a potential probe for DAT PET imaging in the brain.

Synthesis and biological evaluation of 18F-labelled dopamine D3 receptor selective ligands.

The dopamine D3 receptor (D3R) is highly expressed in the limbic regions of the brain and closely related to a variety of neurological disorders including Parkinson's disease, schizophrenia and drug-seeking behavior. In vivo imaging of D3R with radio-labelled tracers and positron emission tomography (PET) has become a powerful technique in related disorders. In this study, we synthesized three novel aromatically 18F-labelled phenylpiperazine-like D3R selective radioactive ligands ([18F]5b, [18F]8b and [18F]11b) and developed a simple, rapid and efficient 18F-labelling method by condition optimization. Radiosynthesis of [18F]5b, [18F]8b and [18F]11b was achieved by 18F-fluorination from nitroarene precursors. Final radiochemical purities of [18F]5b, [18F]8b and [18F]11b solution were > 99% and remained good stability (> 98% for up to 6 h) in PBS and FBS. PET imaging and cellular binding studies revealed that [18F]8b had a higher D3R affinity than [18F]5b and [18F]11b. Autoradiography and biodistribution studies of the brain showed that [18F]8b had medium intensity specific accumulation in the striatum and cortex. Meanwhile, the low skeletal uptake of [18F]8b revealed a good in vivo stability with negligible defluorination. These results indicated that [18F]8b might be a potential 18F-labelled D3R PET imaging agent.

Nucleophilic Substitution of Selenosulfonates with Me3SiCF2Br: Facile and Efficient Access to Bromodifluoromethylated Selenides under Metal-Free Conditions.

A facile synthesis of bromodifluoromethylated selenides under metal-free conditions is described here. Commercially available Me3SiCF2Br and bench-stable selenosulfonates react smoothly to give a broad scope of alkyl- and aryl-substituted bromodifluoromethylated selenides in moderate to good yields via a difluorocarbene intermediate. This protocol features a short reaction time, the absence of toxic waste, good scalability, and successful late-stage modification of bioactive molecules. In addition, the title products can be easily converted to different fluorinated and 18F-labeled selenides.

Molar activity of [18F]FP-(+)-DTBZ radiopharmaceutical: Determination and its effect on quantitative analysis of VMAT2 autoradiography.

[18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ) is a rising positron tracer for imaging vesicular monoamine transporter II (VMAT2) in the central nervous system. The present work was to develop a novel chromatographic method capable of the molar activity (Am) determination of [18F]FP-(+)-DTBZ. As a complement work of the Am measurement, we also investigated the effect of Am on the quantitative analysis of VMAT2 autoradiography with [18F]FP-(+)-DTBZ. The Am determination was performed by high performance liquid chromatography (HPLC) using the non-radioactive standard (FP-(+)-DTBZ) for calibration plot of peak area against concentration. Based on this correlation, the Am of [18F]FP-(+)-DTBZ was calculated and corrected to the end of synthesis. In the quantitative analysis of in vitro VMAT2 autoradiography, the striatum radioactivity uptake together with the uptake ratio of striatum versus cortex reduced along with the decrease of Am and the increase of the FP-(+)-DTBZ content. Therefore, the Am and the corresponding FP-(+)-DTBZ content have a significant effect on the quantitative analysis of VMAT2 autoradiography using [18F]FP-(+)-DTBZ.

Synthesis and Biological Evaluation of [18F]FECNT-d4 as a Novel PET Agent for Dopamine Transporter Imaging.

PURPOSE: The dopamine transporter (DAT) is a marker of the occurrence and development of Parkinson's disease (PD) and other diseases with nigrostriatal degeneration. 2ß-Carbomethoxy-3ß-(4-chlorophenyl)-8-(2-[18F]-fluoroethyl)nortropane ([18F]FECNT), an 18F-labelled tropane derivative, was reported to be a useful positron-emitting probe for DAT. However, the rapid formation of brain-penetrating radioactive metabolites is an impediment to the proper quantitation of DAT in PET studies with [18F]FECNT. Deuterium-substituted analogues have presented better in vivo stability to reduce metabolites. This study aimed to synthesize a deuterium-substituted DAT radiotracer, [18F]FECNT-d4, and to make a preliminary investigation of its properties as a DAT tracer in vivo. PROCEDURES: The ligand [18F]FECNT-d4 was obtained by one-step radiolabelling reaction. The lipophilicity was measured by the shake-flask method. Binding properties of [18F]FECNT-d4 were estimated by in vitro binding assay, biodistribution, and microPET imaging in rats. In vivo stability of [18F]FECNT-d4 was estimated by radio-HPLC. RESULTS: [18F]FECNT-d4 was synthesized at an average activity yield of 46 ± 17 % (n = 15) and the molar activity was 67 ± 12 GBq/µmol. The deuterated tracer showed suitable lipophilicity and the ability to penetrate the blood-brain barrier (brain uptake of 1.72 % ID at 5 min). [18F]FECNT-d4 displayed a high binding affinity for DAT comparable to that of [18F]FECNT in rat striatum homogenates. Biodistribution results in normal rats showed that [18F]FECNT-d4 exhibited a higher ratio of the target to non-target (striatum/cerebellum) at 15 min post administration (5.00 ± 0.44 vs 3.84 ± 0.24 for [18F]FECNT-d4 vs [18F]FECNT). MicroPET imaging studies of [18F]FECNT-d4 in normal rats showed that the ligand selectively localized to DAT-rich striatal regions and the accumulation could be blocked with DAT inhibitor. Furthermore, in the unilateral PD model rat, a significant reduction of the signal was found in the lesioned side relative to the unlesioned side. Striatal standardized uptake value of [18F]FECNT-d4 remained ~4.02 in the striatum between 5 and 20 min, whereas that of [18F]FECNT fell rapidly from 4.11 to 2.95. Radio-HPLC analysis of the plasma demonstrated better in vivo stability of [18F]FECNT-d4 than [18F]FECNT. CONCLUSION: The deuterated compound [18F]FECNT-d4 may serve as a promising PET imaging agent to assess DAT-related disorders.

An escalating treatment strategy for children with severe chronic immune thrombocytopenia: Preliminary report from a single center.

OBJECTIVE: To analyze the effects of escalating treatment strategy in children with severe chronic immune thrombocytopenia (SCITP). METHODS: This was a single-center, retrospective cohort study. Data from children with SCITP who received escalating treatment strategy in our center were collected between June 2017 and August 2019. The escalating strategy included three steps: Step I (six courses of high-dose dexamethasone [HDD]), Step II (HDD combined with low-dose rituximab), and Step III (eltrombopag). RESULTS: A total of 30 cases (18 males and 12 females) were included, with duration of immune thrombocytopenia (ITP) of 20.5 (12.0-96.0) months. After treatment, the remission rate was 36.7% (11/30) and the sustained response (SR) rate was 68.2% (15/22). The distribution (remission rates) from Step I to III was as follows: nine of 30 (33.3%, 3/9); four of 30 (50%, 2/4); 17/30 (29.4%, 5/17), respectively. In eltrombopag (Step III) cases, 47.5% (8/17) maintained a platelet count of ≥50 × 109 /L, 37.5% (3/8) had dose tapering, and 25% (2/8) have successfully discontinued the medication. The number of patients at 12, 24, and 36 months were 30, seven, and two, with a total response and remission rates of 80% (36.7%), 57.1% (28.6%), and 50% (50%), respectively. The total relapse rate was 26.7% (8/30), and three cases from Step II and five cases from Step III. CONCLUSION: The escalating strategy for children SCITP showed an effective improvement rate with 36.7% remission and 68.2% SR, and 30% could benefit and retain SR from HDD treatment. Combined treatment with eltrombopag can reduce the relapse rate of low-dose rituximab.

MicroPET imaging of vesicular monoamine transporter 2 revealed the potentiation of (+)-dihydrotetrabenazine on MPTP-induced degeneration of dopaminergic neurons.

INTRODUCTION: Vesicular monoamine transporter 2 (VMAT2) has been associated with the risk of PD. Genetic reduction of VMAT2 level is reported to increase the vulnerability for dopaminergic neurodegeneration. In this study, by using in vivo microPET imaging with a VMAT2 radioligand [18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ), we investigated the enhanced role of inhibiting VMAT2 in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced loss of dopaminergic neurons. METHODS: The (+)-α-dihydrotetrabenazine ((+)-DTBZ, an inhibitor of VMAT2, 5 mg/kg), or MPTP (low dose (ld): 10 mg/kg, high dose (hd): 30 mg/kg) or both of them were intraperitoneally injected into C57BL/6 mice for 5 or 10 consecutive days. MicroPET imaging with [18F]FP-(+)-DTBZ was performed to test the dopaminergic neuronal integrity. [18F]FP-(+)-DTBZ uptake in striatum was quantified as standardized uptake value (SUV). The pathological changes in the striata and substantia nigra were confirmed by measuring the DA contents and immunohistochemical staining of tyrosine hydroxylase (TH). RESULTS: In vivo imaging results showed that the striatal SUVs of both DTBZ&MPTPld and MPTPhd groups were substantially declined compared to the baseline. Moreover, the striatal uptakes of [18F]FP-(+)-DTBZ in DTBZ&MPTPld and MPTPhd groups were obviously lower than the control, DTBZ group and MPTPld group. Notably, the decrease of the striatal uptake in the DTBZ&MPTPld/10d group was more serious than the DTBZ&MPTPld/5d group and comparable to the MPTPhd group. Consistently, the ratios of DA metabolites to DA in DTBZ&MPTPld/10d and MPTPhd mice were significantly increased. The correlation analysis showed that SUVs were highly correlated to the striatal dopaminergic fiber density and TH-positive dopaminergic neuron number in the substantia nigra. CONCLUSIONS: MicroPET brain imaging with [18F]FP-(+)-DTBZ noninvasively revealed that (+)-DTBZ co-administration significantly aggravated the neurotoxicity of MPTP to dopaminergic neurons, suggesting that inhibition of VMAT2 may be related to the pathogenesis of PD and tracing VMAT2 activity with PET imaging is of potential value in monitoring PD progression.

High-dose dexamethasone as a replacement for traditional prednisone as the first-line treatment in children with previously untreated primary immune thrombocytopenia: a prospective, randomized single-center study.

Immune thrombocytopenia (ITP) is one of the most common acquired immune-mediated bleeding disorders found in children. Prednisone is usually considered a first-line therapeutic agent for ITP in children. Yet, prolonged exposure to prednisone has been associated with certain side effects. This prospective randomized study comparatively assessed the efficacy and safety of short-course high-dose dexamethasone (HDD) and standard prednisone (PDN) as a first-line treatment for children with previously untreated primary ITP. Two hundred eleven children were randomized into the HDD (n = 110) and PDN (n = 101) groups. There was no difference in baseline characteristics between the two groups (p > 0.05). Early response rates were 92.7% and 93% (p = 0.923); initial response rates were 93.6% and 95% (p = 0.658) and durable response rates were 90% and 91% (p = 0.787) in the HDD and PDN groups, respectively. More remission patients in the HDD group compared with the PDN group (86.3% vs. 80.1%) at 12th month after treatment, yet no statistical difference was observed (p = 0.703). Bleeding events were 10.9% and 14.8% (p = 0.105), and bleeding score improvement rates were 78.2% and 76.2% (p = 0.284) in the HDD and PDN groups, respectively. Cushing's disease, weight gain and infection rates were higher in the PDN group compared to the HDD group (80% vs. 10%, p = 0.001; 74.2% vs. 13.6%, p = 0.001; and 26% vs. 11.8%, p = 0.012) 1 month after treatment. HDD showed non-inferior efficacy and fewer glucocorticoid-related adverse effects compared with PDN. These findings indicated that HDD could be considered as a first-line treatment in children with previously untreated primary ITP, thus replacing standard PDN.

PET imaging with [18F]FP-(+)-DTBZ in 6-OHDA-induced partial and full unilaterally-lesioned model rats of Parkinson's disease and the correlations to the biological data.

OBJECTIVE: The deficit of dopaminergic neurons in the nigrostriatal pathway is one of the pathological features of Parkinson's disease (PD). The decline of vesicular monoamine transporter type 2 (VMAT2) has been verified to relate with the severity of PD. The purpose of this study was to evaluate the ability of [18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ) to detect dopaminergic neuron dysfunction in a standard rat model of PD using PET imaging. Specifically, two different doses of 6-hydroxydopamine (6-OHDA) were injected unilaterally into the medial forebrain bundle (MFB) to create the models with two different severities. METHODS: Male Sprague-Dawley rats were intracranially injected with 8 µg 6-OHDA (partial lesion group), 16 µg 6-OHDA (full lesion group) and vehicle (sham group) into MFB, respectively. Thirty minutes static [18F]FP-(+)-DTBZ microPET scanning was performed to determine the dopaminergic neuron integrity on the 28th day post-injection and the behavioral tests were carried out in the next two days. Then, the rats were decapitated, and the brains were collected for biogenic amines content analysis or dissected for autoradiography and immunohistochemical (IHC) staining. The correlations of PET results to the behavioral, biological, histological, autoradiography results were analyzed, respectively. RESULTS: The standardized uptake value ratio (ST to CB) of [18F]FP-(+)-DTBZ in the ipsilateral striata decreased significantly in partial lesion group and full lesion group. Compared with the sham group, the ratio of the standardized uptake value in ipsilateral striatum to that in contralateral striatum decreased by 57.09 ± 2.30% (full lesion group) and 25.31 ± 5.70% (partial lesion group), respectively. The dopaminergic neuronal dysfunction was corroborated by in vitro autoradiography, IHC, and quantitative analysis of DA as well as its metabolites concentration tests. The motor function impairments of 6-OHDA-treated animals were manifested by a series of behavioral tests. The results of microPET imaging were linearly correlated with behavioral, biological, histological, and autoradiography results, respectively. CONCLUSION: Our data suggest that [18F]FP-(+)-DTBZ may be useful for detecting different degrees of dopaminergic neuronal lesions by PET imaging in PD models induced by 6-OHDA.

Phase I clinical study with different doses of 99mTc-TRODAT-1 in healthy adults.

OBJECTIVES: To study the pharmacokinetics, biodistribution, and injection doses of 99mTc-TRODAT-1 in healthy adults. METHODS: Thirty healthy individuals comprising 15 females and 15 males were randomly divided into three groups and the injection doses of 99mTc-TRODAT-1 of group 1, 2, and 3 were 370 MBq, 740 MBq, and 1110 MBq, respectively. Assessments of subjective symptoms and tests were performed before and after injection. Blood and urine collections and whole-body planar imaging were analyzed at various time points. Bilateral brain striatal SPECT images obtained at 3.5 h PI were assessed visually and semiquantitatively. RESULTS: No serious adverse events or deaths were observed in our study. The pharmacokinetic analysis showed that 99mTc-TRODAT-1 was eliminated rapidly from the circulation, with just about 4% of the injected dose remaining in blood at 1 h post-injection. The mean cumulative urinary excretion over 24 h was just 2.96 ± 0.96%ID. The time-activity curve demonstrated that the radioactivity was mainly in liver and abdomen. The highest absorbed dose was in the dose-limiting organ, liver (20.88 ± 4.45 × 10-3 mSv/MBq). The average effective dose was 5.22 ± 1.05 × 10-3 mSv/MBq. The clarity of striatal images assessed visually in group 1 was worse than that in group 2 and 3. The semiquantitative analysis showed that there were no differences in striatum/cerebellum between the three groups (group 1: 1.77 ± 0.11, group 2: 1.62 ± 0.14, and group 3: 1.75 ± 0.20; P = 0.088). CONCLUSIONS: 99mTc-TRODAT-1 was safe to use in humans and showed the status of dopaminergic neurons specifically and clearly. The injection dose we suggested was 740 MBq.

Correction to: A phase 2, open-label, multi-center study to evaluate the efficacy and safety of 99mTc-TRODAT-1 SPECT to detect Parkinson's disease.

The corresponding author of the article would like to remove "Jian Wang" in the author group.

An Efficient Automated Radiosynthesis and Bioactivity Confirmation of VMAT2 Tracer [18F]FP-(+)-DTBZ.

PURPOSE: The aim of this study was to optimize the radiolabeling method of [18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ) to fulfill the demand of preclinical and clinical application. PROCEDURES: Optimized labeling conditions were performed by altering the molar ratio of precursor to base (P/B), base species, solvents, reaction temperature, reaction time, and precursor concentration through manual radiosynthesis of [18F]FP-(+)-DTBZ. The conditions with the highest radiochemical yield (RCY) were applied to automated radiosynthesis, and the crude product was purified with a Sep-Pak Plus C18 cartridge. Quality control and stability of [18F]FP-(+)-DTBZ were carried out by HPLC. In vitro cellular uptake and blocking assays were conducted in human neuroblastoma cell line SH-SY5Y. In vivo imaging with small animal positron emission tomography (microPET) was performed with Sprague-Dawley rats. RESULTS: Under the optimized conditions (P/K2CO3 = 1:8, heating at 120 °C for 3 min in dimethyl sulfoxide), an RCY of 88.7 % was obtained with 1.0 mg precursor. The optimized reaction conditions were successfully applied to an automated module and gave a high activity yield (AY) of 30-55 % in about 40 min with a > 99.0 % radiochemical purity (RCP) and a > 44.4 GBq/µmol molar activity (Am). Stability test displayed that the RCP retained > 98.0 % in 8 h in saline and in phosphate buffer saline (PBS, pH 7.4). In vitro cellular uptake assay showed accumulation of [18F]FP-(+)-DTBZ in SH-SY5Y cells, which could be significantly inhibited by vesicular monoamine transporter 2 (VMAT2) inhibitor DTBZ. MicroPET images of rat brain displayed that the striatum showed the highest uptake with a standardized uptake value (SUV) of 3.91 ± 0.30 at ~ 70 min. Co-injection with DTBZ (1.0 mg/kg) resulted in a 75 % decrease of the striatal SUV, confirming the specificity of [18F]FP-(+)-DTBZ to VMAT2. CONCLUSIONS: We obtained an optimized radiolabeling method of [18F]FP-(+)-DTBZ and successfully applied it to a commercial available module. The automated synthesis gave a high AY and RCP of [18F]FP-(+)-DTBZ with high and specific binding to VMAT2, facilitating its routine application for VMAT2 tracing.

A phase 2, open-label, multi-center study to evaluate the efficacy and safety of 99mTc-TRODAT-1 SPECT to detect Parkinson's disease.

OBJECTIVES: To assess the efficacy and safety of 99mTc-TRODAT-1 SPECT in diagnosing Parkinson's disease (PD). METHODS: 99mTc-TRODAT-1 SPECT imaging was performed in 34 healthy controls and 96 PD patients 2.5 h later after injection. The striatal image was evaluated visually and semi-quantitively. Sensitivity and specificity of 99mTc-TRODAT-1 SPECT were analyzed according to Hoehn and Yahr scale (HYS). Based on HYS, the PD patients were divided into mild (HYS 1-2) and moderate (HYS 3-5) groups. The uptake ratios of striatum (ST) and cerebellum (CB) in contralateral, ipsilateral and bilateral striatum in different groups were calculated and analyzed. The safety was assessed. RESULTS: The sensitivity and specificity of 99mTc-TRODAT-1 SPECT to discriminate PD patients from healthy subjects were 98.96% and 94.12% and it has perfect agreement with HYS (κ = 0.94, p < 0.001). The sensitivity to diagnose mild and moderate PD was 43.42% and 95% separately. The uptake ratio in PD patients was significantly lower than that in healthy controls (1.37 ± 0.13 vs 1.68 ± 0.18, p < 0.001). And the uptake ratio in contralateral side was markedly reduced in unilateral PD patients as compared with the ipsilateral side (1.50 ± 0.20 vs 1.46 ± 0.21, p < 0.001). The striatal uptakes in affected striatum and bilateral striatum were reduced with increasing disease severity between healthy control versus mild stage versus moderate stage in the affected striatum and bilateral striatum in PD patients. No serious adverse events or death was observed after injecting 99mTc-TRODAT-1. CONCLUSION: We demonstrated that 99mTc-TRODAT-1 was a safety radiotracer which can be used in clinic to diagnose PD using SPECT.

Systemic bioinformatics analysis of recurrent aphthous stomatitis gene expression profiles.

Recurrent aphthous stomatitis (RAS) represents the most common chronic oral diseases with the prevalence ranges from 5% to 25% for different populations. Its pathogenesis remains poorly understood, which limits the development of effective drugs and treatment methods. In this study, we conducted systemic bioinformatics analysis of gene expression profiles from the Gene Expression Omnibus (GEO) to identify potential drug targets for RAS. We firstly downloaded the gene microarray datasets with the accession number of GSE37265 from GEO and performed robust multi-array (RMA) normalization with affy R programming package. Secondly, differential expression genes (DEGs) in RAS samples compared with control samples were identified based on limma package. Enriched gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of DEGs were obtained through the Database for Annotation, Visualization and Integrated Discovery (DAVID). Finally, protein-protein interaction (PPI) network was constructed based on the combination of HPRD and BioGrid databases. What's more, we identified modules of PPI network through MCODE plugin of Cytoscape for the purpose of screening of valuable targets. As a result, 915 genes were found to be significantly differential expression in RAS samples and biological processes related to immune and inflammatory response were significantly enriched in those genes. Network and module analysis identified FBXO6, ITGA4, VCAM1 and etc as valuable therapeutic targets for RAS. Finally, FBXO6, ITGA4, and VCAM1 were further confirmed by real time RT-PCR and western blot. This study should be helpful for the research and treatment of RAS.

Preclinical Comparative Study of (68)Ga-Labeled DOTA, NOTA, and HBED-CC Chelated Radiotracers for Targeting PSMA.

(68)Ga-labeled, low-molecular-weight imaging agents that target the prostate-specific membrane antigen (PSMA) are increasingly used clinically to detect prostate and other cancers with positron emission tomography (PET). The goal of this study was to compare the pharmacokinetics of three PSMA-targeted radiotracers: (68)Ga-1, using DOTA-monoamide as the chelating agent; (68)Ga-2, containing the macrocyclic chelating agent p-SCN-Bn-NOTA; and (68)Ga-DKFZ-PSMA-11, currently in clinical trials, which uses the acyclic chelating agent, HBED-CC. The PSMA-targeting scaffold for all three agents utilized a similar Glu-urea-Lys-linker construct. Each radiotracer enabled visualization of PSMA+ PC3 PIP tumor, kidney, and urinary bladder as early as 15 min post-injection using small animal PET/computed tomography (PET/CT). (68)Ga-2 demonstrated the fastest rate of clearance from all tissues in this series and displayed higher uptake in PSMA+ PC3 PIP tumor compared to (68)Ga-1 at 1 h post-injection. There was no significant difference in PSMA+ PC3 PIP tumor uptake for the three agents at 2 and 3 h post-injection. (68)Ga-DKFZ-PSMA-11 demonstrated the highest uptake and retention in normal tissues, including kidney, blood, spleen, and salivary glands and PSMA-negative PC3 flu tumors up to 3 h post-injection. In this preclinical evaluation (68)Ga-2 had the most advantageous characteristics for PSMA-targeted PET imaging.

Effects of anesthetics on vesicular monoamine transporter type 2 binding to ¹8F-FP-(+)-DTBZ: a biodistribution study in rat brain.

OBJECTIVES: The in vivo binding analysis of vesicular monoamine transporter type 2 (VMAT2) to radioligand has provided a means of investigating related disorders. Anesthesia is often inevitable when the investigations are performed in animals. In the present study, we tested effects of four commonly-used anesthetics: isoflurane, pentobarbital, chloral hydrate and ketamine, on in vivo VMAT2 binding to (18)F-FP-(+)-DTBZ, a specific VMAT2 radioligand, in rat brain. METHODS: The transient equilibrium time window for in vivo binding of (18)F-FP-(+)-DTBZ after a bolus injection was firstly determined. The brain biodistribution studies under anesthetized and awake rats were then performed at the equilibrium time. Standard uptake values (SUVs) of the interest brain regions: the striatum (ST), hippocampus (HP), cortex (CX) and cerebellum (CB) were obtained; and ratios of tissue to cerebellum were calculated. RESULTS: Isoflurane and pentobarbital did not alter distribution of (18)F-FP-(+)-DTBZ in the brain relative to the awake group; neither SUVs nor ratios of ST/CB and HP/CB were altered significantly. Chloral hydrate significantly increased SUVs of all the brain regions, but did not significantly alter ratios of ST/CB and HP/CB. Ketamine significantly increased SUVs of the striatum, hippocampus and cortex, and insignificantly increased the SUV of the cerebellum; consequently, ketamine significantly increased ratios of ST/CB and HP/CB. CONCLUSIONS: It is concluded that in vivo VMAT2 binding to (18)F-FP-(+)-DTBZ are not altered by isoflurane and pentobarbital, but altered by chloral hydrate and ketamine. Isoflurane and pentobarbital may be promising anesthetic compounds for investigating in vivo VMAT2 binding. Further studies are warranted to investigate the interactions of anesthetics with VMAT2 binding potential with in vivo PET studies.

Angiotensin II promotes an osteoblast-like phenotype in porcine aortic valve myofibroblasts.

OBJECTIVES: The mechanisms for pathogenesis of cardiac valve calcification were explored by studying the regulation of the Wnt signaling pathway during the transformation from cardiac valvular myofibroblasts to osteoblast-like phenotype. METHODS: Studies were carried on primary cultured porcine aortic valvular myofibroblasts. The cells were randomly divided into four groups and treated with angiotensin II (Ang II) according to the following: Ang II (10(-6) mol/l), Valsartan (Val) (10(-5) mol/l), Ang II plus Val (Ang II 10(-6) mol/l + Val 10(-5) mol/l) or mock treated as the control. Protein expression of Bone morphogenetic protein 2 (BMP2), Alkaline phosphatase (ALP), and Wnt pathway components, Wnt3a and ß-catenin, was investigated to assess the activation of the Wnt signaling pathway and determine whether cells undergo the transformation to osteoblast-like phenotype. RESULT: Ang II treatment of myofibroblasts led to significant up-regulation of α-SMA expression and activation of the cells. Neither the BMP2 or ALP proteins, nor the mRNA was detectable in the control group or the Val-treated group; however, there was a significant increase in Ang II-treated group (P < 0.01). The Wnt/ß-catenin signaling ligand, Wnt3a, was not expressed in the control or Val-treated groups, whereas in Ang II-treated cells, both Wnt3a and ß-catenin gene expression were enhanced (P < 0.01).The effect of Ang II can be inhibited by the addition of Val (P < 0.05). CONCLUSION: Ang II might act on the Ang II receptor on valvular interstitial cells (VICs) and lead to activation of the Wnt/ß-catenin pathway and hence cause the activation, differentiation and proliferation of myofibroblasts, and finally, osteoblast-like phenotype transformation, leading to calcification of heart valves.