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We previously showed a hydroxamic acid‐based histone deacetylase inhibitor (HDACi), compound 13, provides neuroprotection against chronic cerebral hypoperfusion (CCH) both in vitro under oxygen‐glucose deprivation (OGD) conditions and in vivo under bilateral common carotid artery occlusion (BCCAO) conditions. Intriguingly, the protective effect of this HDACi is via H3K14 or H4K5 acetylation–mediated differential BDNF isoform activation. BDNF is involved in cell proliferation and differentiation in development, synaptic plasticity and in learning and memory related with receptors or synaptic proteins. B6 mice underwent BCCAO and were randomized into 4 groups; a sham without BCCAO (sham), BCCAO mice injected with DMSO (DMSO), mice injected with HDACi‐compound 13 (compound 13) and mice injected with suberoylanilide hydroxamic acid (SAHA). The cortex and hippocampus of mice were harvested at 3 months after BCCAO, and levels of BDNF, AMPA receptor and dopamine receptors (D1, D2 and D3) were studied using Western blotting analysis or immunohistochemistry. We found that the AMPA receptor plays a key role in the molecular mechanism of this process by modulating HDAC. This protective effect of HDACi may be through BDNF; therefore, activation of this downstream signalling molecule, for example by AMPA receptors, could be a therapeutic target or intervention applied under CCH conditions.

Shiou-Shiow Farn,1,2 Kang-Wei Chang,3 Wan-Chi Lin,1 Hung-Man Yu,1 Kun-Liang Lin,1 Yu-Chin Tseng,1 Yu Chang,1 Chung-Shan Yu,2,4 Wuu-Jyh Lin1 1Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, 32546, Taiwan; 2Department of Biomedical Engineering and Environmental Sciences, National Tsing-Hua University, Hsinchu, 300, Taiwan; 3Laboratory Animal Center, Office of Research and Development, Taipei Medical University, Taipei, 11031, Taiwan; 4Institute of Nuclear Engineering and Science, College of Nuclear Science, National Tsing-Hua University, Hsinchu, 300, TaiwanCorrespondence: Wuu-Jyh Lin; Chung-Shan Yu Email WJLin@seecurellc.com; csyu@mx.nthu.edu.twIntroduction: Novel radiotracer development for imaging dopamine transporters is a subject of interest because although [99mTc]TRODAT-1, [123I]β-CIT, and [123I]FP-CIT are commercially available; 99Mo/99mTc generator is in short supply and 123I production is highly dependent on compact cyclotron. Therefore, we designed a novel positron emission tomography (PET) tracer based on a tropane derivative through C-2 modification to conjugate NOTA for chelating 68Ga, a radioisotope derived from a 68Ge/68Ga generator.Methods: IPCAT-NOTA 22 was synthesized and labeled with [68Ga]GaCl4− at room temperature. Biological studies on serum stability, LogP, and in vitro autoradiography (binding assay and competitive assay) were performed. Furthermore, ex vivo autoradiography, biodistribution, and dynamic PET imaging studies were performed in Sprague Dawley rats.Results: [68Ga]IPCAT-NOTA 24 obtained had a radiochemical yield of ≥ 90% and a specific activity of 4.25 MBq/nmol. [68Ga]IPCAT-NOTA 24 of 85% radiochemical purity (RCP%) was stable at 37°C for up to 60 minutes in serum with a lipophilicity of 0.88. The specific binding ratio (SBR%) reached 15.8 ± 6.7 at 60 minutes, and the 85% specific uptake could be blocked through co-injection at 100- and 1000-fold of the cold precursor in in vitro binding studies. Tissue regional distribution studies in rats with [68Ga]IPCAT-NOTA 24 showed striatal uptake (0.02% at 5 minutes and 0.007% at 60 minutes) with SBR% of 6%, 25%, and 62% at 5– 15, 30– 40, and 60– 70 minutes, respectively, in NanoPET studies. The RCP% of [68Ga]IPCAT-NOTA 24 at 30 minutes in vivo remained 67.65%.Conclusion: Data described here provide new information on the design of PET probe of conjugate/pendent approach for DAT imaging. Another chelator or another direct method of intracranial injection must be used to prove the relation between [68Ga]IPCAT-NOTA 24 uptake and transporter localization.Keywords: Parkinson disease, dopamine transporter, Ga-68

Cut foliage of Monstera deliciosa is widely used in flower arrangement due to its long vase life and striking foliage pattern. Variegated Monstera of commercial importance is scarce. Therefore, we examined the potential of mutagenesis in obtaining variegated mutants by gamma ray irradiating the seeds. The germination rate was reduced by increasing the irradiation dosage. The LD50 dosage was between 10 to 25 Gy. We further compared the survival rate of seeds from different source at 0, 7.5, 10, and 12.5 Gy. Dosage higher than 12.5 Gy was required to achieve LD50 germination rate. Next, seeds pre-soaked for 5 days were compared to dry seeds for their sensitivity to gamma irradiation at various dosages (10, 12.5, 15, 17.5, 20, and 22.5 Gy). The highest germination rate was obtained by 10 Gy of dry seeds and 12.5 Gy of soaked seeds. The lowest germination rate was observed by 22.5 Gy for both dry and soaked seeds. The soaked seeds apparently were more tolerant to the damage caused by higher dosage of irradiation. Different pattern of leaf variegation was obtained after gamma ray irradiation, including light green to yellow green sectors.

A new naphthol derivative, [F-18]FEONM, has been designed to be a new Tau protein PET imaging molecule for detecting Tau tangle status of Alzheimer's disease in a transgenic mouse model. In order to synthesize this molecule, 2-acetyl-6-methoxynaphthalene was the starting compound and needed five steps preparation to bonding functional and leaving group for preparing the precursor. Radiofluorination on the precursor was carried out by a modified [F-18]FDG autosynthesizer. After half an hour processing, it yielded more than 99% chemical and radiochemical purity product at up to 60% yield. Radiofluorination kinetic study showing 80% [F-18]FEONM would be produced within the first 5 min. The radiofluorination gap function factor is 0.122 for 150 min reaction. Recovery yield of crude [F-18]FEONM could be up to 60% by semi-preparative HILIC HPLC column purification with 95% ethanol elution. Brain glioma tumor mice PET imaging were performed after tail vein injecting [F-18]FEONM. Binding in mice brain tumor reached steady state after 30 min injection and shows 30–70% higher uptake compared to normal mouse. The static brain tumor uptake showed the summation accumulation binding rate was 60% faster than normal mouse. In vitro postmortem AD patient brain slice binding showed 70% higher uptake than normal brain. The uptake of spherical stem cells also showed higher association with neuronal differentiation and PET imaging of Tau and ABeta transgenic mice also showed visualized difference. The specific binding ratio of hippocampus to cerebellum of control mouse is 46.56%, cortex to cerebellum is 11.08% in a 12-month-old P301S Tau transgenic mouse; hippocampus to cerebellum is 106.66%, cortex to cerebellum is 82.48%. Relative ratio of hippocampus to cerebellum of a P301S mouse to control mouse is 2.29, cortex to cerebellum is 7.44.

A reversed-phase high-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was applied to study the forced degradation behavior and stability of epidepride. 123 I radioisotope-labeled epidepride, [(-)- N -{[(2 S )-1-ethylpyrrolidin-2-yl]methyl}-5-iodo-2,3- dimethoxybenzamide] is a radiotracer with a high affinity for dopamine D 2 receptors in the brain and has been used as an imaging agent for single-photon emission computed tomography. HPLC studies were performed using 127 I-epidepride (the nonradioactive compound), instead of 123 I-epidepride, with an RP-18 column using a mobile phase consisting of methanol, acetonitrile, and ammonium acetate (pH 7.0, 10 mM). The eluent flow rate and the wavelength for HPLC detection were 0.5 mL/min and 210 nm, respectively. The ligand was exposed to acid (1 N HCl) and alkaline (1 N NaOH) media and was subjected to oxidative decomposition at room temperature using 3% H 2 O 2 and to thermal decomposition at 50°C. After various reaction times (30 minutes, 1 hour, 2 hours, 8 hours, and 24 hours), the substances were investigated by HPLC and LC-MS/MS. Although no decomposition products were observed after the acidic, alkaline, and thermal treatments, >80% of the initial amount of 127 I-epidepride was oxidized within 24 hours in the presence of H 2 O 2 . Only one major oxidation product with an m/z value of 435 was observed, in addition to the 127 I-epidepride species (m/z 419). The product was characterized by LC-MS/MS fragmentation, and the deteriorated type and fragmentation pathways were proposed for epidepride.

[(123)I]Epidepride is a radio-tracer with very high affinity for dopamine D(2)/D(3) receptors in brain. The importance of alteration in dopamine D(2)/D(3) receptor binding condition has been wildly verified in schizophrenia. In the present study we set up a rat schizophrenia model by chronic injection of a non-competitive NMDA receptor antagonist, MK-801, to examine if [(123)I]epidepride could be used to evaluate the alterations of dopamine D(2)/D(3) receptor binding condition in specific brain regions.Rats were given repeated injection of MK-801 (dissolved in saline, 0.3mg/kg) or saline for 1month. Afterwards, total distance traveled (cm) and social interaction changes were recorded. Radiochemical purity of [(123)I]epidepride was analyzed by Radio-Thin-Layer Chromatography (chloroform: methanol, 9:1, v/v) and [(123)I]epidepride neuroimages were obtained by ex vivo autoradiography and small animal SPECT/CT. Data obtained were then analyzed to determine the changes of specific binding ratio.Chronic MK-801 treatment for a month caused significantly increased local motor activity and induced an inhibition of social interaction. As shown in [(123)I]epidepride ex vivo autoradiographs, MK-801 induced a decrease of specific binding ratio in the striatum (24.01%), hypothalamus (35.43%), midbrain (41.73%) and substantia nigra (37.93%). In addition, [(123)I]epidepride small animal SPECT/CT neuroimaging was performed in the striatum and midbrain. There were statistically significant decreases in specific binding ratio in both the striatum (P.01) and midbrain (P.05) between the saline and MK-801 group.These results suggest that [(123)I]epidepride is a useful radio-tracer to reveal the alterations of dopamine D(2)/D(3) receptor binding in a rat schizophrenia model and is also helpful to evaluate therapeutic effects of schizophrenia in the future.

3,4-Methylenedioxymethamphetamine (MDMA), also known as “Ecstasy”, is a common recreational drug of abuse. Several previous studies have attributed the central serotonergic neurotoxicity of MDMA to distal axotomy, since only fine serotonergic axons ascending from the raphe nucleus are lost without apparent damage to their cell bodies. However, this axotomy has never been visualized directly in vivo. The present study examined the axonal integrity of the efferent projections from the midbrain raphe nucleus after MDMA exposure using in vivo manganese-enhanced magnetic resonance imaging (MEMRI). Rats were injected subcutaneously six times with MDMA (5 mg/kg) or saline once daily. Eight days after the last injection, manganese ions (Mn2+) were injected stereotactically into the raphe nucleus, and a series of MEMRI images was acquired over a period of 38 h to monitor the evolution of Mn2+-induced signal enhancement across the ventral tegmental area, the medial forebrain bundle (MFB), and the striatum. The MDMA-induced loss of serotonin transporters was clearly evidenced by immunohistological staining consistent with the Mn2+-induced signal enhancement observed across the MFB and striatum. MEMRI successfully revealed the disruption of the serotonergic raphe-striatal projections and the variable effect of MDMA on the kinetics of Mn2+ accumulation in the MFB and striatum.

[(18)F]Flurobutyl ethacrynic amide ([(18)F]FBuEA) was prepared from the precursor tosylate N-Boc-N-[4-(toluenesulfonyloxy)butyl]ethacrynic amide with a radiochemical yield of 3%, a specific activity of 48 GBq/μmol and radiochemical purity of 98%. Chemical conjugation of [(18)F]FBuEA with glutathione (GSH) via a self-coupling reaction and enzymatic conjugation under catalysis of glutathiontransferase alpha (GST-α) and π provided about 41% yields of radiochemical conjugated product [(18)F]FBuEA-GSH, 85% and 5-16%, respectively. The catalytic selectivity of this tracer toward GST-alpha was addressed. Positron emission tomography (PET) imaging of [(18)F]FBuEA in normal rats showed that a homogeneous pattern of radioactivity was distributed in the liver, suggesting a catalytic role of GST. By contrast, PET images of [(18)F]FBuEA in rats with thioacetamide-induced cholangiocarcinoma displayed a heterogeneous pattern of radioactive accumulation with cold spots in tumor lesions. PET imaging with [(18)F]FBuEA could be used for early diagnosis of hepatic tumor with a low GST activity as well as liver function.

It is predicted that depression will become the most common neurological disease in the new millennium. Its incidence is currently about 3% of diseases worldwide. Serotonin is an essential neurotransmitter for the central and peripheral nervous systems and plays a crucial role in neuropsychiatric disorders. (123)I-labeled ADAM was developed to facilitate an early diagnosis of serotonin transporter (SERT) abnormalities in the brain. Many studies have confirmed that the binding of this radiotracer to SERTs is associated with depression. The aim of this study was to evaluate the acute and subacute toxicity of ADAM and to determine its no observed adverse effect level (NOAEL) by administering it via intravenous injection to Sprague-Dawley rats for 14 consecutive days. None of the animals died, and no treatment-related clinical signs were observed. Urinalysis, hematology, and clinical chemistry analysis revealed that daily administration of ADAM (2-2-dimethylaminomethylphenylthio-5-iodophenylamine) for 2 weeks had no toxicological effects. It is concluded that ADAM exerts no adverse toxic effects on this animal model. The NOAEL was 155 microg/kg/day.

6-[ 124 I]iodo-2-(4′-N,N-dimethylamino)-phenylimidazo[1,2-a]pyridine ([ 124 I]IMPY) was synthesized and characterized as a positron-emitting probe to identify Alzheimer's disease in transgenic mouse models. A significant reduction in radioactivity retention in the hippocampus and frontal cortex by co-incubation with nonradioactive IMPY was observed. Highly specific retention of radioactivity in beta-amyloid-rich regions of brain sections was also noted. This study demonstrated that [ 124 I]IMPY was a promising probe for the mouse model and may be useful for positron emission tomography to image beta-amyloid plaques in the human brain.

Benzo[a]pyrene (B[a]P) has been shown to produce DNA adducts and to initiate pulmonary carcinogenesis in animals. We observed differential susceptibility to B[a]P in two human lung adenocarcinoma cell lines, A427 and CL3. DNA adducts were induced by B[a]P treatment in CL3 cells, however, A427 cells were much less responsive to B[a]P treatment. Cytochrome P450 1A1 (CYP1A1) is involved in bioactivation of B[a]P in nonhepatic tissues. Cotreatment with α-naphthoflavone, a CYP1A1 inhibitor, abolished DNA adduct formation by B[a]P in CL3 cells. Nevertheless, CYP1A1 inducer β-naphthoflavone, enhanced DNA adduct formation by B[a]P in both A427 and CL3 cells. Both enzyme activity and mRNA levels of CYP1A1 were highly induced by 1 or 10 μM B[a]P treatment for 24 hr in CL3 cells but not in A427 cells. Protein levels of AhR and aryl hydrocarbon receptor nuclear translocator (Arnt) were similar in A427 and CL3 cells before B[a]P treatment. However, B[a]P induced a retarded band with the [32P]-dioxin responsive element in CL3 cells, but not in A427 cells. This study demonstrated that variation in AhR-mediated CYP1A1 induction contributes to differential susceptibility to B[a]P-DNA adduct formation in human lung cells. Since AhR and/or Arnt function is impaired in A427 cells, this cell line offers a model for investigating the repression mechanisms of CYP1A1 induction by B[a]P in lung cells.

This study is concerned with the development of an agent for single photon emission computer tomography (SPECT) for imaging inflammation and tumor progression. [ 123 I]Iodooctyl fenbufen amide ([ 123 I]IOFA) was prepared from the precursor N-octyl-4-oxo-4-(4 0 -(trimethylstannyl)biphenyl-4-yl) butanamide with a radiochemical yield of 15%, specific activity of 37 GBq/mmol, and radiochemical purity of 95%. Analysis of the binding of [ 123 I]IOFA to COX-1 and COX-2 enzymes by using HPLC and a gel filtration column showed a selectivity ratio of 1:1.3. An assay for the competitive inhibition of substrate transfer showed that IOFA exhibited a comparable IC50 value compared to fenbufen. In the normal rat liver, a lower level and homogeneous pattern of [ 123 I]IOFA radioactivity was observed by SPECT. In contrast, in the rat liver with thioacetamide-induced cholangiocarcinoma, a higher uptake and heterogeneous pattern of [ 123 I]IOFA radioactivity was seen as hot spots in tumor lesions by SPECT imaging. Importantly, elevated COX-1 and COX-2 expressions from immunostaining were found in the bile ducts of tumor rats but not of normal rats. Therefore, [ 123 I]IOFA was found to exhibit the potential for imaging tumors that over-express COX.