Synthesis and evaluation of 2-(2'-((dimethylamino)methyl)-4'-(2-fluoroethoxy-substituted)phenylthio)benzenamine derivatives as potential positron emission tomography imaging agents for serotonin transporters.

A series of diphenylsulfide derivatives with various substitutions at the 4-position on phenyl ring A and different lengths of the 2-fluoroethoxy-substituted side-chain at the 4'-position on ring B were synthesized and evaluated as potential positron emission tomography (PET) imaging agents for serotonin transporters (SERT). These ligands exhibited high SERT binding affinities (Ki = 0.11-1.3 nM) and the 4-methyl-substituted (4-Me) compounds 7a and 8a displayed excellent selectivity for SERT versus norepinephrine transporters (NET) (392- and 700-fold, respectively). In the parallel artificial membrane permeability assay (PAMPA), these ligands demonstrated moderate to high brain penetration, and the 4-Me analogs showed higher BBB permeability than the corresponding 4-F analogs. The 2-fluoroethoxy-substituted ligands showed higher metabolic stability and lower lipophilicity than 4-F-ADAM. [18F]7a-c were readily prepared using an automatic synthesizer and exhibited significant uptake and slow washout in rat brains. At 120 min after iv injection, [18F]7a exhibited the highest uptake in the midbrain, whereas [18F]7b exhibited the highest uptake in the hypothalamus and midbrain. After treatment with citalopram, a SERT-selective ligand, the uptake of [18F]7a in the hypothalamus and striatum was significantly decreased. The potent and highly selective SERT binding and the selective and reversible accumulation in SERT-rich brain regions suggested that [18F]7a is a promising lead for the further development of novel [18F]-labeled PET imaging agents for SERT binding sites in the brain.

Targeting histone deacetylase 4/ubiquitin-conjugating enzyme 9 impairs DNA repair for radiosensitization of hepatocellular carcinoma cells in mice.

Several strategies to improve the efficacy of radiation therapy against hepatocellular carcinoma (HCC) have been investigated. One approach is to develop radiosensitizing compounds. Because histone deacetylase 4 (HDAC4) is highly expressed in liver cancer and known to regulate oncogenesis through chromatin structure remodeling and controlling protein access to DNA, we postulated that HDAC4 inhibition might enhance radiation's effect on HCC cells. HCC cell lines (Huh7 and PLC5) and an ectopic xenograft were pretreated with HDAC inhibitor or short hairpin RNA to knock down expression of HDAC4 and then irradiated (2.5-10.0 Gy). We evaluated cell survival by a clonogenic assay; apoptosis by Annexin V immunofluorescence; γH2AX, Rad51, and HDAC4 by immunofluorescence staining; HDAC4, Rad51, and ubiquitin-conjugating enzyme 9 (Ubc9) in HCC cell nuclei by cell fractionation and confocal microscopy; physical interaction between HDAC4/Rad51/Ubc9 by immunoprecipitation; and the downstream targets of HDAC4 knockdown by immunoblotting. Both HDAC4 knockdown and HDAC inhibitor enhanced radiation-induced cell death and reduced homologous recombination repair of DNA double-strand breaks and protein kinase B activation, leading to increased apoptosis. HDAC4 knockdown with or without an HDAC inhibitor significantly delayed tumor growth in a radiation-treated xenograft model. Radiation stimulated nuclear translocation of Rad51 in an HDAC4-dependent manner and the binding of Ubc9 directly to HDAC4, which led to Ubc9 acetylation. Moreover, these effects were accompanied by HDAC4/Ubc9/Rad51 complex dissociation through inhibiting nuclear translocation. Conclusion: HDAC4 signaling blockade enhances radiation-induced lethality in HCC cells and xenografts. These findings raise the possibility that HDAC4/Ubc9/Rad51 complex in DNA repair may be a target for radiosensitization of HCC. (Hepatology 2018;67:586-599).

Phase II study of metabolic response to one-cycle chemotherapy in patients with locally advanced esophageal squamous cell carcinoma.

BACKGROUND: In the treatment of esophageal squamous cell carcinoma (ESCC), the optimal use of 18fluorodeoxyglucose positron emission tomography (PET) in measuring metabolic tumor response is undetermined. We launched a phase II trial to evaluate early metabolic response to one-cycle induction chemotherapy in patients with locally advanced ESCC. METHODS: ESCC patients in stage classification T3N0, N1M0, or M1a (American Joint Committee on Cancer, 6th edition) received one-cycle chemotherapy comprising paclitaxel, cisplatin, and 24-h infusional 5-fluorouracil and leucovorin on days 1 and 8, followed by neoadjuvant chemoradiotherapy, 40 Gy, with paclitaxel/cisplatin and then esophagectomy. PET was performed at baseline and day 14 of chemotherapy. The primary endpoint was pathologic complete response (pCR). We hypothesized early metabolic responders with >35% reduction in maximum standardized uptake value (SUVmax), would have better pCR Results. RESULTS: Sixty-six patients were enrolled. The median progression-free survival (PFS) and overall survival (OS) were 16 months (95% confidence interval [CI], 9-27) and 22 months (16-40), respectively. The early metabolic response rate was 55%; and the pCR rate was 34% in the esophagectomy population. The early metabolic response was not associated with pCR or survival. In an exploratory analysis, the postchemotherapy SUVmax was an independent prognostic factor for pCR, PFS, and OS. CONCLUSION: Our study failed to validate the predefined early metabolic response for pCR to neoadjuvant chemoradiotherapy in locally advanced ESCC patients. However, postchemotherapy SUVmax may be prognostic and predictive, and warrants further study.

Single allele Lmbrd1 knockout results in cardiac hypertrophy.

BACKGROUND/PURPOSE: LMBD1 protein, a type IV-B plasma membrane protein possessing nine putative trans-membrane domains, was previously demonstrated at cellular level to play a critical part in the signaling cascade of insulin receptor through its involvement in regulating clathrin-mediated endocytosis. However, at physiological level, the significance of LMBD1 protein in cardiac development remains unclear. METHODS: To understand the role of Lmbrd1 gene involved in the cardiac function, heterozygous knockout mice were used as an animal model system. The pathological outcomes were analyzed by micro-positron emission tomography, ECG acquisition, cardiac ultrasound, and immunohistochemistry. RESULTS: By studying the heterozygous knockout of Lmbrd1 (Lmbrd1+/-), we discovered that lack of Lmbrd1 not only resulted in the increase of cardiac-glucose uptake, pathological consequences were also observed. Here, we have distinguished that Lmbrd1+/- is sufficient in causing cardiac diseases through a pathway independent of the recessive vitamin B12 cblF cobalamin transport defect. Lmbrd1+/- mice exhibited an increase in myocardial glucose uptake and insulin receptor signaling that is insensitive to the administration of additional insulin. Pathological symptoms such as cardiac hypertrophy, ventricular tissue fibrosis, along with the increase of heart rate and cardiac muscle contractility were observed. As Lmbrd1+/- mice aged, the decrease in ejection fraction and fraction shortening showed signs of ventricular function deterioration. CONCLUSION: The results suggested that Lmbrd1 gene not only plays a significant role in mediating the energy homeostasis in cardiac tissue, it may also be a key factor in the regulation of cardiac function in mice.

Benefits of Neuronal Preferential Systemic Gene Therapy for Neurotransmitter Deficiency.

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive disease that impairs synthesis of dopamine and serotonin. Children with AADC deficiency exhibit severe motor, behavioral, and autonomic dysfunctions. We previously generated an IVS6+4A>T knock-in mouse model of AADC deficiency (Ddc(KI) mice) and showed that gene therapy at the neonatal stage can rescue this phenotype. In the present study, we extended this treatment to systemic therapy on young mice. After intraperitoneal injection of AADC viral vectors into 7-day-old Ddc(KI) mice, the treated mice exhibited improvements in weight gain, survival, motor function, autonomic function, and behavior. The yfAAV9/3-Syn-I-mAADC-treated mice showed greater neuronal transduction and higher brain dopamine levels than AAV9-CMV-hAADC-treated mice, whereas AAV9-CMV-hAADC-treated mice exhibited hyperactivity. Therefore, neurotransmitter-deficient animals can be rescued at a young age using systemic gene therapy, although a vector for preferential neuronal expression may be necessary to avoid hyperactivity caused by this treatment.

Search of Unknown Fever Focus Using PET in Critically Ill Children With Complicated Underlying Diseases.

OBJECTIVES: PET/CT with F-fluorodeoxyglucose can be used to image cellular metabolism and has been used for evaluating fever of unknown origin in adults. However, there are limited studies about the role of F-fluorodeoxyglucose PET/CT in evaluation of fever of unknown origin in critically ill children, especially those presenting with complicated underlying diseases under treatment. Here, we report our preliminary experience using F-fluorodeoxyglucose PET/CT in this specific group of patients. DESIGN: Retrospective observational study. SETTING: PICUs of a university hospital. PATIENTS: Nineteen critically ill children (mean age, 5.7 yr old) with complicated underlying diseases requiring intensive care support underwent F-fluorodeoxyglucose PET/CT to evaluate fever of unknown origin. The median hospitalized stay was 34 days (range, 15-235 d) and fever of at least 7 days (mean, 21.6 d; range, 7-52 d). The PET scan was advocated after all routine microbiology, and conventional imaging showed negative or inconclusive results. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The F-fluorodeoxyglucose PET/CT findings (blinded to the final clinical diagnosis) were compared with final histopathology, culture, serology results, or follow-up imaging. A final diagnosis was made in 16 patients (84.2%). F-fluorodeoxyglucose PET/CT accurately localized the source of fever in 14 patients, confers to a sensitivity of 87.5% (14 of 16; 95% CI, 0.604-0.978). A false-positive scan in a patient led to subsequent unnecessary investigations. Two false-negative F-fluorodeoxyglucose PET/CT images were later attributed to relapse of underlying disease in the bone marrow and renal abscesses, respectively. In the other two patients where F-fluorodeoxyglucose PET/CT also showed negative findings, fever subsided shortly thereafter without treatment. CONCLUSIONS: Our preliminary experience suggests that F-fluorodeoxyglucose PET/CT may be clinically beneficial in evaluating fever of unknown origin in children with complicated underlying diseases mandating intensive support in ICUs if usual investigative methods are unsuccessful. Further large prospective studies are needed to validate these findings.

The Incremental Diagnostic Performance of Coronary Computed Tomography Angiography Added to Myocardial Perfusion Imaging in Patients with Intermediate-to-High Cardiovascular Risk.

PURPOSE: Several studies have suggested that a combined approach of stress myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) can provide diagnostic results with excellent accuracy. We aimed to explore whether the addition of CCTA to stress MPI provides incremental diagnostic value in intermediate-to-high cardiovascular risk patients. METHODS: A total of 106 consecutive patients (93 male, 65 ± 10.4 years) underwent coronary artery calcium scoring (CACS), CCTA and (201)Thallium stress MPI before coronary angiography was reviewed. Thirty-seven patients (34.9%) had a history of proven coronary artery disease (CAD) or revascularization procedures, and four had documented non-significant CAD (3.8%). The remaining patients consisted of 17 (16.0%) classified as intermediate, and 48 (45.3%) as the high-risk groups. RESULTS: Obstructive CAD was diagnosed by invasive coronary angiography in 88 patients with 161 vessels. The sensitivity and specificity in a patient-based analysis for obstructive CAD were 99% and 17% for CCTA, 80% and 50% for MPI and 91% and 67% for the combined method, respectively. The per-vessel diagnostic sensitivity and specificity were 95% and 54% for CCTA, 59% and 75% for MPI and 84% and 76% for the combined method. There were significant differences (p < 0.05) when comparing the combined method with MPI or CCTA by areas under the curve in a patient- or vessel-based analysis. However, CACS of 400 or more could not further stratify the patients with obstructive CAD. CONCLUSIONS: CCTA, not CACS, provided additional diagnostic values to stress MPI in patients with intermediate-to-high cardiovascular risk. KEY WORDS: Coronary artery disease (CAD) • Coronary computed tomography angiography (CCTA) • Myocardial perfusion imaging (MPI) • Single-photon emission computed tomography (SPECT).

Data-driven respiratory motion tracking and compensation in CZT cameras: a comprehensive analysis of phantom and human images.

BACKGROUND: This study described a method for tracking and compensating respiratory motion in cadmium-zinc-telluride (CZT) cameras. We evaluated motion effects on myocardial perfusion imaging and assessed the usefulness of motion compensation in phantom and clinical studies. METHODS: SPECT studies were obtained from an oscillating heart phantom and 552 patients using CZT cameras with list-mode acquisition. Images were reformatted in 500-ms frames, and the activity centroid was calculated as respiratory signal. The myocardial perfusion, left ventricular (LV) wall thickness, and LV volume were assessed before and after the motion compensation technique. RESULTS: In phantom studies, we documented only minimal bias between simulated and measured shifts. Significantly reduced tracer activity, increased wall thickness and decreased volume in scans with 15 mm or more axial shifts were noted. In clinical studies, there was a higher prevalence of significant motion after treadmill exercise. The motion compensation technique could successfully compensate those motion artifacts. CONCLUSION: The described method allows for tracking and compensating respiratory motion in CZT cameras. Significant respiratory motion is still not uncommon using CZT cameras, especially in patients who underwent treadmill tests. Motion blurring can be compensated using image processing techniques and image quality could be significantly improved.

Sonic Hedgehog inhibition as a strategy to augment radiosensitivity of hepatocellular carcinoma.

BACKGROUND AND AIM: Sonic Hedgehog (SHH) is a regulator in tumorigenesis of hepatocellular carcinoma (HCC). This study aimed to determine whether radiation-induced SHH signaling occurs in HCC and whether SHH inhibitor acts as a radiosensitizer. METHODS: The in vitro effects of combining SHH ligand (recombinant human SHH) or inhibitor (cyclopamine) with irradiation were evaluated in the human HCC cell lines, Huh-7 and PLC/PRF/5, and murine cell line BNL. Cell survival and apoptosis were measured using a colony formation assay, annexin-V staining, and poly (ADP-ribose) polymerase activation. Western blotting and immunofluorescence staining were used to detect protein expression. The in vivo response to radiotherapy and/or cyclopamine was tested in BALB/c mice bearing an orthotopic allogeneic tumor. RESULTS: Treatment of HCC cells with irradiation and SHH ligand had a protective effect on clonogenic cell survival. Treatment with irradiation and cyclopamine was a more potent inhibitor of cell proliferation than either modality alone. The antiproliferative activity of cyclopamine was attributable to apoptosis induction. Radiation dose-dependently upregulated the expression of Gli-1 (a transcription factor induced by SHH), and this effect was observed mainly in the nucleus. When combined with cyclopamine, irradiation inhibited Gli-1 and increased DNA double-strand breakage. Radiotherapy increased SHH and Gli-1 expression in allogeneic tumor. When compared with radiotherapy alone, cyclopamine with radiotherapy reduced the mean tumor size of orthotopic tumors by 67% (P < 0.05). CONCLUSION: Combining an SHH inhibitor with radiotherapy may enhance HCC cell and orthotopic tumor radiosensitivity.

LMBD1 protein serves as a specific adaptor for insulin receptor internalization.

Energy homeostasis is crucial for maintaining normally functioning cells; disturbances in this balance often cause various diseases. The limb region 1 (LMBR1) domain containing 1 gene (lmbrd1) encodes the LMBD1 protein that possesses 9 putative transmembrane domains. LMBD1 has been suggested to be involved in the lysosome in aiding the export of cobalamin. In this study, we determined that LMBD1 plays a regulatory role in the plasma membrane. A micro-positron emission tomography analysis showed that a single-allele knock-out of lmbrd1 increased the (18)F-fluorodeoxyglucose uptake in murine hearts. In addition, the knockdown of lmbrd1 resulted in an up-regulated signaling of the insulin receptor (IR) and its downstream signaling molecule, Akt. Confocal and live total internal reflection fluorescence microscopy showed that LMBD1 co-localized and co-internalized with clathrin and the IR, but not with the transferrin receptor. The results of the mutation analysis and phenotypic rescue experiments indicate that LMBD1 interacts with adaptor protein-2 and is involved in the unique clathrin-mediated endocytosis of the IR. LMBD1 selectively interacts with the IR. The knockdown of lmbrd1 attenuated IR endocytosis, resulting in the perturbation of the IR recycling pathway and consequential enhancement of the IR signaling cascade. In summary, LMBD1 plays an imperative role in mediating and regulating the endocytosis of the IR.

Plasma tau as a window to the brain-negative associations with brain volume and memory function in mild cognitive impairment and early Alzheimer's disease.

Neurofibrillary tangles are associated with cognitive dysfunction, and hippocampal atrophy with increased CSF tau markers. However, the plasma tau levels of Alzheimer's disease (AD) have not been well studied. We investigated plasma tau by using an immunomagnetic reduction assay in 20 patients with mild cognitive impairment (MCI) due to AD, 10 early AD dementia, and 30 healthy elders (HE). All received a 3D-brain MRI scan and a set of cognitive function test. We explored their relationships with both brain structure and cognitive functions. Images were analyzed to determine the brain volumes and gray matter densities. Patients with MCI or early AD had significantly increased plasma tau levels compared with HE. Plasma tau levels were negatively associated with the performance of logical memory, visual reproduction, and verbal fluency; also negatively associated with volume of total gray matter, hippocampus, amygdala; and gray matter densities of various regions. Regression analyses indicated that logical memory explained 0.394 and hippocampus volume predicted .608 of the variance of plasma tau levels, both P < 0.001. Education years were negatively associated with the gray matter densities of the supramarginal (r = -0.407), middle temporal gyrus (r = -0.40) and precuneus (r = -0.377; all P < 0.05) in HE; and negatively associated with plasma tau levels in patients (r = -0.626). We propose that plasma tau may serve as a window to both structure and function of the brain. Higher education is a protective factor against AD and is associated with lower plasma tau levels in patients.

Prognostic value of semiquantification NP-59 SPECT/CT in primary aldosteronism patients after adrenalectomy.

PURPOSE: Primary aldosteronism (PA), characterized by an excessive production of aldosterone, affects 5-13 % of patients with hypertension. Accurate strategies are needed for the timely diagnosis of PA to allow curability and prevention of excessive cardiovascular events and related damage. This study aimed to evaluate the usefulness of semiquantification of (131)I-6ß-iodomethyl-norcholesterol (NP-59) single photon emission computed tomography (SPECT)/CT in differentiating aldosterone-producing adenoma (APA) from idiopathic adrenal hyperplasia (IAH) and in predicting clinical outcomes after adrenalectomy. METHODS: We retrospectively reviewed 49 PA patients who had undergone adrenalectomy after NP-59 SPECT/CT within 1 year. A conventional visual scale (VS) and two semiquantitative parameters generated from SPECT/CT, adrenal to liver ratio (ALR) and lesion to contralateral ratio of bilateral adrenal glands (CON), with cutoff values calculated by receiver-operating characteristic (ROC) analysis, were compared with pathology results and postsurgical outcomes to determine the accuracy. RESULTS: An ALR cutoff of 1.84 and a CON cutoff of 1.15 showed an ability to distinguish adenoma from hyperplasia similar to VS (p = 0.2592 and 0.1908, respectively). An ALR cutoff of 2.28 and a CON cutoff of 1.11 yielded the highest sensitivity and specificity to predict postsurgical outcomes, and an ALR of 2.28 had an ability superior to VS (p = 0.0215), while a CON of 1.11 did not (p = 0.1015). Patients with either ALR or CON greater than the cutoff had a high probability of positive postsurgical outcomes (n = 36/38), while patients with both ALR and CON less than the cutoff had a low probability of positive postsurgical outcomes (n = 2/11). CONCLUSION: Semiquantification of NP-59 scintigraphy has an ability similar to VS in differentiating APA from IAH, but an excellent ability to predict postsurgical outcomes of adrenalectomy. An ALR or CON greater than the cutoff strongly suggests benefits from adrenalectomy, and both ALR and CON less than the cutoff implies a reduced chance of improvement in postsurgical outcome.

Normal values and symptom correlation of a simplified oatmeal-based gastric emptying study in the Chinese population.

BACKGROUND AND AIM: Instant oatmeal has been proposed as a good alternative to the standardized low-fat egg white test meal for gastric emptying studies. We aim to establish normal values of oatmeal-based gastric emptying scintigraphy and test its correlation with gastroparesis symptoms in the Chinese population. METHODS: This study prospectively enrolled 60 healthy volunteers, 30 functional dyspepsia and 30 diabetes patients with gastroparesis symptoms. All participants were evaluated using the Gastroparesis Cardinal Symptom Index. Each participant ingested instant oatmeal mixed with 1 mCi of (99m) Tc diethylenetriaminepentacetic acid, and serial imaging was immediately acquired for 3 h in the supine position using a left anterior oblique projection. Time-activity curves were generated and quantitative parameters were determined. Normal values were established from healthy volunteers and further applied in the symptomatic patients. RESULTS: All participants finished the test meal and tolerated the procedure well. All gastric emptying parameters were not significantly affected by age or gender. Values above the 95th percentile of T1/2 , gastric retention at 1, 2, and 3 h (85 min, 65%, 28%, and 8%, respectively) were indicative of delayed gastric emptying. Values below the 5th percentile of gastric retention at 0.5 and 1 h (40% and 15%, respectively) were indicative of rapid gastric emptying. The lower gastric retention limit at 0.5 and 1 h were 40% and 15%, respectively. Four (13.3%) diabetes and four (13.3%) functional dyspepsia patients had delayed emptying while three diabetes patients (10%) had rapid emptying. Gastric emptying parameters correlated best with vomiting (r = 0.621) and nausea (r = 0.566) in diabetes patients. CONCLUSIONS: We established normal values of oatmeal-based gastric emptying scintigraphy and observed good correlation with cardinal gastroparesis symptoms in the Chinese population.

Regulation of the dopaminergic system in a murine model of aromatic L-amino acid decarboxylase deficiency.

Aromatic l-amino acid decarboxylase (AADC) is responsible for the syntheses of dopamine and serotonin. Children with AADC deficiency exhibit compromised development, particularly with regard to their motor functions. Currently, no animal model of AADC deficiency exists. We inserted an AADC gene mutation (IVS6+4A>T) and a neomycin-resistance gene into intron 6 of the mouse AADC (Ddc) gene. In the brains of homozygous knock-in (KI) mice (Ddc(IVS6/IVS6)), AADC mRNA lacked exon 6, and AADC activity was <0.3% of that in wild-type mice. Half of the KI mice were born alive but grew poorly and exhibited severe dyskinesia and hindlimb clasping after birth. Two-thirds of the live-born KI mice survived the weaning period, with subsequent improvements in their growth and motor functions; however, these mice still displayed cardiovascular dysfunction and behavioral problems due to serotonin deficiencies. The brain dopamine levels in the KI mice increased from 9.39% of the levels in wild-type mice at 2weeks of age to 37.86% of the levels in wild-type mice at 8weeks of age. Adult KI mice also exhibited an exaggerated response to apomorphine and an elevation of striatal c-Fos expression, suggesting post-synaptic adaptations. Therefore, we generated an AADC deficient mouse model, in which compensatory regulation allowed the mice to survive to adulthood. This mouse model will be useful both for developing gene therapies for AADC deficiency and for designing treatments for diseases associated with neurotransmitter deficiency.

The effects of 3-month atorvastatin therapy on arterial inflammation, calcification, abdominal adipose tissue and circulating biomarkers.

PURPOSE: (18)F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT has the potential to track vascular inflammation and monitor therapeutic response. The purpose of this study was to determine the association between arterial inflammation, calcification and serological biomarkers in subjects with atherosclerosis, and to assess their therapeutic response to 12-week atorvastatin treatment. METHODS: Forty-three statin-naïve subjects with atherosclerosis received atorvastatin (40 mg/day) for 12 weeks and underwent (18)F-FDG PET/CT, coronary calcification and abdominal adipose tissue volume measurements. A panel of serological biomarkers was analysed. Arterial inflammation was measured at seven arterial segments and normalized to venous FDG activity to produce target to background ratios (TBR). Thirty-four subjects without cardiovascular disease who repeated PET 1-4 years apart for routine health check-ups were retrospectively evaluated for comparison. RESULTS: The baseline mean TBR values in atherosclerotic patients were positively correlated with age (R = 0.36), body mass index (R = 0.54), abdominal visceral adipose tissue volume (R = 0.65), coronary calcification score (R = 0.40), levels of low-density lipoprotein cholesterol (R = 0.54), matrix metalloproteinase (MMP)-9 (R = 0.46) and fatty acid binding protein 4 (FABP4) (R = 0.67, all p < 0.05). The TBR as well as high-sensitivity C-reactive protein (hsCRP), E-selectin, MMP-9, monocyte chemotactic protein 1, FABP4 and follistatin values were reduced significantly after the 12-week atorvastatin treatment. The TBR reduction marginally correlated with changes in MMP-9 levels (R = 0.56, p = 0.05). The control group, whose median age was younger, by comparison had lower hsCRP and arterial TBR than the subjects with atherosclerosis (all p < 0.05), and moreover had a slight but insignificant increase in mean TBR at their 2.5±0.8 year follow-up. CONCLUSION: The medium dose of atorvastatin over a 12-week period resulted in a significant reduction of arterial inflammation as well as various circulating biomarkers.

Active coping with stress suppresses glucose metabolism in the rat hypothalamus.

We used 18F-fluorodeoxyglucose small-animal positron-emission tomography to determine whether different styles of coping with stress are associated with different patterns of neuronal activity in the hypothalamus. Adult rats were subjected to immobilization (IMO)-stress or to a non-immobilized condition for 30 min, in random order on separate days, each of which was followed by brain-scanning. Some rats in the immobilized condition were allowed to actively cope with the stress by chewing a wooden stick during IMO, while the other immobilized rats were given nothing to chew on. Voxel-based statistical analysis of the brain imaging data shows that chewing counteracted the stress-induced increased glucose uptake in the hypothalamus to the level of the non-immobilized condition. Region-of-interest analysis of the glucose uptake values further showed that chewing significantly suppressed stress-induced increased glucose uptake in the paraventricular hypothalamic nucleus and the anterior hypothalamic area but not in the lateral hypothalamus. Together with the finding that the mean plasma corticosterone concentration at the termination of the IMO was also significantly suppressed when rats had an opportunity to chew a wooden stick, our results showed that active coping by chewing inhibited the activation of the hypothalamic-pituitary-adrenal axis to reduce the endocrine stress response.

Development of 68Ga-glycopeptide as an imaging probe for tumor angiogenesis.

Objective. This study was aimed to study tissue distribution and tumor imaging potential of (68)Ga-glycopeptide (GP) in tumor-bearing rodents by PET. Methods. GP was synthesized by conjugating glutamate peptide and chitosan. GP was labeled with (68)Ga chloride for in vitro and in vivo studies. Computer outlined region of interest (counts per pixel) of the tumor and muscle (at the symmetric site) was used to determine tumor-to-muscle count density ratios. To ascertain the feasibility of (68)Ga-GP in tumor imaging in large animals, PET/CT imaging of (68)Ga-GP and (18)F-FDG were conducted in New Zealand white rabbits bearing VX2 tumors. Standard uptake value of tumors were determined by PET up to 45 min. To determine blood clearance and half-life of (68)Ga-GP, blood samples were collected from 10 seconds to 20 min. Results. Radiochemical purity of (68)Ga-GP determined by instant thin-layer chromatography was >95%. Tumor uptake values (SUV) for (68)Ga-GP and (18)F-FDG in New Zealand white rabbits bearing VX2 tumors were 3.25 versus 7.04. PET images in tumor-bearing rats and rabbits confirmed that (68)Ga-GP could assess tumor uptake. From blood clearance curve, the half-life of (68)Ga-GP was 1.84 hr. Conclusion Our data indicate that it is feasible to use (68)Ga-GP to assess tumor angiogenesis.

Neuroimaging findings in a brain with Niemann-Pick type C disease.

Niemann-Pick type C disease (NPC) is a rare autosomal recessive lipid storage disorder caused by impaired cellular functions in processing and transporting low-density lipoprotein-cholesterol. In this report, we present magnetic resonance imaging (MRI), magnetic resonance spectrography (MRS) and 18-fluoro-2-deoxyglucose positron emission tomography (PET) imaging results for a 22-year-old male NPC patient. The patient's two MRI studies (at age 19 years and 22 years) demonstrated progressive changes of brain atrophy that were more prominent at the frontal lobes, and hyperintense signals in bilateral parietal-occipital periventricular white matter. MRS (at age 19 years) revealed no significant decrease in N-acetyl aspartate/choline ratio in the left frontal central white matter. PET (at age 22 years) showed significant bilateral hypometabolism in the prefrontal cortex and dorsomedial thalamus, and hypermetabolism in the parietal-occipital white matter, lenticular nucleus of the basal ganglia, cerebellum and pons. The imaging findings noted by MRI, MRS and 18-fluoro-2-deoxyglucose PET offered a possible supplementary explanation for the clinical neurological symptoms of this NPC patient.

Cellular localization of the organic cation transporters, OCT1 and OCT2, in brain microvessel endothelial cells and its implication for MPTP transport across the blood-brain barrier and MPTP-induced dopaminergic toxicity in rodents.

The cellular localization of organic cation transporter (OCT) 1 and OCT2 in isolated brain microvessel endothelial cells from humans, rats, and mice and in cultured adult rat brain endothelial cells was examined by confocal microscopy and in isolated luminal and abluminal membrane fractions by Western blot analysis. Cellular uptake of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was measured with or without OCT1/OCT2 silencing. The interaction between MPTP and amantadine was studied by in vitro kinetic analysis and in vivo brain microdialysis. MPTP-induced dopaminergic toxicity was examined by measuring dopamine levels in the brain striatum and by positron emission tomography scanning. The results showed that both OCT1 and OCT2 were mainly expressed on the luminal side of brain microvessel endothelial cells and adult rat brain endothelial cells. Cellular uptake of MPTP was significantly (p < 0.05) decreased by about 53%, 60%, or 91% following silencing of OCT1, OCT2, or both, respectively. Amantadine competitively inhibited MPTP uptake in vitro and significantly (p < 0.05) reduced the area under the time-concentration curve for MPTP and MPP(+) in the brain extracellular fluid in rats and mice by 65-70% and 35-85%, respectively. MPTP-induced dopaminergic toxicity in mice was ameliorated by amantadine without stimulating dopamine turnover. In conclusion, OCT1 and OCT2 are important for MPTP transfer across the blood-brain barrier and amantadine reduces the blood-brain barrier transfer of MPTP and MPTP-induced dopaminergic toxicity in rodents.

Genotype-phenotype correlates in Taiwanese patients with early-onset recessive Parkinsonism.

We screened for mutations in the PARKIN, DJ-1, and PINK1 genes in a Taiwanese cohort (68 probands; 58 sporadic and 10 familial) with early-onset parkinsonism (EOP, onset <50 years of age). We identified 9 patients harboring mutations in PARKIN (three compound heterozygous and six single heterozygous carriers), 3 patients with heterozygous PINK1 mutations (including two novel substitutions M341I and P209A), and no DJ-1 mutations. Our frequencies of PARKIN (two allele mutation, 4.4%; single allele, 8.8%) and PINK1 (single heterozygous, 4.4%) mutations in Taiwanese-Chinese are similar to those in Caucasian and other Asian EOP patients. Although the role of heterozygosity of recessive genes in EOP remains to be resolved, molecular analysis and functional imaging will play a decisive role in differential diagnosis and determined therapeutic strategy.