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author:("Lee, wondo")
1.  Gadolinium Complex of 125I/127I-RGD-DOTA Conjugate as a Tumor-Targeting SPECT/MR Bimodal Imaging Probe 
ACS Medicinal Chemistry Letters  2012;4(2):216-219.
The work describes the synthesis and in vivo application of [Gd(L)(H2O)]·xH2O, where L is a (125I/127I-RGD)- DOTA conjugate, as a tumor-targeting SPECT/MR bimodal imaging probe. Here, (125I/127I-RGD)-DOTA signifies a “cocktail mixture” of radioisotopic (1a, L = 125I-RGD-DOTA) and natural (1b, L = 127I-RGD-DOTA) Gd complexes. The two complexes are chemically equivalent as revealed by HPLC, and their cocktail mixture exhibits the integrin-specific tumor enhancement, demonstrating that they constitute essentially a single bimodal imaging probe. Employment of a cocktail mixture thus proves to be a sole and practical approach to overcome the sensitivity difference problem between MRI and SPECT.
doi:10.1021/ml3003499
PMCID: PMC4027545  PMID: 24900644
dual modality; SPECT/MR; RGD peptide; small molecule; tumor targeting
2.  DOSE REDUCTION IN CT USING BISMUTH SHIELDING: MEASUREMENTS AND MONTE CARLO SIMULATIONS 
Radiation protection dosimetry  2009;138(4):10.1093/rpd/ncp278.
Objective
In this research, using direct measurements and Monte Carlo calculations, we evaluated the potential dose reduction achieved by bismuth shielding in computed tomography. Patient dose was measured using an ionization chamber in a polymethylmethacrylate (PMMA) phantom which had five measurement points at the center and periphery. We performed simulations using the MCNPX code. For both the bare and the bismuth-shielded phantom, the differences of dose values between experiment and simulation were within 9%. The dose reductions due to the bismuth shielding were 1.2–55% depending on the measurement points, X-ray tube voltage, and the type of shielding. The amount of dose reduction was significant for the position covered by bismuth shielding (34–46% for head and 41–55% for body phantom in average) and negligible for other peripheral positions. The artifact on the reconstructed images were minimal when the distance between the shielding and the organs was more than 1 cm, and hence the shielding should be selectively located to protect critical organs such as the eye lens, thyroid, and breast. The simulation results using PMMA phantom was compared with those using a realistically voxelized phantom (KTMAN-2). For eye and breast, the simulation results using PMMA and KTMAN-2 phantom were similar with each other while, for thyroid, the simulation results were different due to the discrepancy of locations and the size of phantoms. The dose reductions achieved by bismuth and lead shielding were compared with each other and the results showed that the difference of the dose reductions achieved by two materials was less than 2~3 %.
doi:10.1093/rpd/ncp278
PMCID: PMC3878978  PMID: 19959602
3.  Nonalcoholic fatty liver disease is associated with coronary artery disease in Koreans 
AIM: To investigate whether nonalcoholic fatty liver disease (NAFLD) affects coronary artery disease (CAD) and identify candidate mediators.
METHODS: Patients who underwent coronary angiography were consecutively recruited. The patients were classified into four groups by coronary artery stenosis: A, insignificant; B, one-vessel disease; C, two-vessel disease; and D, three-vessel disease. Abdominal ultrasonography was performed to determine the presence of a fatty liver and categorize by grade: 0, no evidence; 1, mild; 2, moderate; and 3, severe. We measured not only known CAD risk factors, but also serum insulin, HOMA-index, adiponectin, interleukin-6, tumor necrosis factor-α and high-sensitivity C-reactive protein levels.
RESULTS: Of the 134 patients who met the inclusion criteria, 82 (61.2%) had ultrasonographically diagnosed NAFLD. Among the 46 patients with CAD, 37 (80.4%) had evidence of a fatty liver. The two groups (A vs B-D) were significantly different in terms of age, total cholesterol, triglycerides, low-density lipoprotein levels and fatty liver. Coronary artery stenosis was strongly associated with fatty liver in a grade-dependent manner (P = 0.025). In binary logistic regression, NAFLD was a significant independent predictor of CAD (P = 0.03, OR = 1.685; 95%CI: 1.051-2.702). Among the candidate mediators, the serum adiponectin level showed a trend toward lowering based on CAD progression (P = 0.071).
CONCLUSION: NAFLD is an independent risk factor for CAD in a grade-dependent manner. Moreover, adiponectin might be related to the pathogenesis of NAFLD.
doi:10.3748/wjg.v19.i38.6453
PMCID: PMC3801316  PMID: 24151364
Nonalcoholic fatty liver disease; Coronary artery disease; Coronary angiography; Adiponectin; Insulin resistance
4.  Very Early Onset of Amiodarone-Induced Pulmonary Toxicity 
Korean Circulation Journal  2013;43(10):699-701.
Amiodarone is a widely used antiarrhythmic agent. Among its various adverse effects, amiodarone-induced pulmonary toxicity (APT) is the most life threatening complication, which has been described mostly in patients who have been in treatment with high accumulative doses for a long duration of time. However, amiodarone therapy in short-term duration induced APT was rarely reported. We describe a case of a 54-year-old man who is presented with symptoms of APT after a few days of therapy for post-myocardial infarction ventricular tachycardia. For early diagnosis and successful treatment, awareness and high suspicion of this rare type of early onset APT is crucial in patients with amiodarone therapy.
doi:10.4070/kcj.2013.43.10.699
PMCID: PMC3831017  PMID: 24255655
Amiodarone; Drug toxicity; Myocardial infarctions; Arrhythmias, cardiac
5.  DRD1 Associations with Smoking Abstinence Across Slow and Normal Nicotine Metabolizers 
Pharmacogenetics and Genomics  2012;22(7):551-554.
Nicotine metabolism and genetic variation have an impact on nicotine addiction and smoking abstinence, but further research is required. The nicotine metabolite ratio (NMR) is a robust biomarker of nicotine metabolism used to categorize slow and normal nicotine metabolizers (lower 25th quartile cutoff). In two randomized clinical trials of smoking abstinence treatments, we conducted NMR-stratified analyses on smoking abstinence across 13 regions coding for nicotinic acetylcholine receptors and proteins involved in the dopamine reward system. Gene × NMR interaction P-values were adjusted for multiple correlated tests, and we used a Bonferroni-corrected α-level of 0.004 to determine system-wide significance. Three SNPs in DRD1 (rs11746641, rs2168631, rs11749035) had significant interactions (0.001 ≤ adjusted P-values ≤ 0.004), with increased odds of abstinence within slow metabolizers (ORs=3.1–3.5, 95% CI 1.7–6.7). Our findings support the role of DRD1 in nicotine dependence, and identify genetic and nicotine metabolism profiles that may interact to impact nicotine dependence.
doi:10.1097/FPC.0b013e3283539062
PMCID: PMC3376177  PMID: 22495174
Genetic association studies; heterogeneity; smoking abstinence; nicotine metabolism; nicotine metabolite ratio; DRD1
6.  Gender Stratified Gene and Gene–Treatment Interactions in Smoking Cessation 
The pharmacogenomics journal  2011;12(6):521-532.
We conducted gender-stratified analyses on a systems-based candidate gene study of 53 regions involved in nicotinic response and the brain-reward pathway in two randomized clinical trials of smoking cessation treatments (placebo, bupropion, transdermal and nasal spray nicotine replacement therapy). We adjusted P-values for multiple correlated tests, and used a Bonferroni corrected α-level of 5 × 10−4 to determine system-wide significance. Four SNPs (rs12021667, rs12027267, rs6702335, rs12039988; r2>0.98) in erythrocyte membrane protein band 4.1 (EPB41) had a significant male-specific marginal association with smoking abstinence (OR=0.5; 95% CI 0.3–0.6) at end of treatment (adjusted P<6 × 10−5). rs806365 in cannabinoid receptor 1 (CNR1) had a significant male-specific gene-treatment interaction at 6-month follow-up (adjusted P=3.9 × 10−5); within males using nasal spray, rs806365 was associated with a decrease in odds of abstinence (OR=0.04; 95% CI 0.01–0.2). While the role of CNR1 in substance abuse has been well studied, we report EPB41 for the first time in the nicotine literature.
doi:10.1038/tpj.2011.30
PMCID: PMC3208134  PMID: 21808284
Genetic association studies; heterogeneity; smoking cessation
7.  Heteronuclear Gd-99mTc Complex of DTPA-Bis(histidylamide) Conjugate as a Bimodal MR/SPECT Imaging Probe 
ACS Medicinal Chemistry Letters  2012;3(4):299-302.
The work describes the synthesis and in vivo application of heterotrimetallic complexes of the type {Gd(H2O)[(M(H2O)(CO)3)2(1)]} {1 = DTPA-bis(histidyl-amide); M = Re (3a); 99mTc (3b)} for dual modality MR/SPECT imaging. Here, the DTPA-bis(histidylamide) conjugate functions as a trinucleating chelate incorporating Gd in the DTPA core with Re or 99mTc in the pair of histidylamide side arms. The two complexes are chemically equivalent as revealed by HPLC, and their “cocktail mixture” (3a + 3b) has demonstrated itself to be essentially a single bimodal imaging probe. The present system has thus overcome the sensitivity difference problem between MRI and SPECT and paved the way for practical applications.
doi:10.1021/ml200285p
PMCID: PMC4025745  PMID: 24900467
dual modality; MR/SPECT; imaging probe; cocktail mixture; heterotrimetallic Gd-[99mTc]2/[Re]2 complexes
8.  Dopamine genes and nicotine dependence in treatment seeking and community smokers 
We utilized a cohort of 828 treatment seeking self-identified white cigarette smokers (50% female) to rank candidate gene single nucleotide polymorphisms (SNPs) associated with the Fagerström Test for Nicotine Dependence (FTND), a measure of nicotine dependence which assesses quantity of cigarettes smoked and time- and place-dependent characteristics of the respondent’s smoking behavior. 1123 SNPs at 55 autosomal candidate genes, nicotinic acetylcholine receptors and genes involved in dopaminergic function, were tested for association to baseline FTND scores adjusted for age, depression, education, sex and study site. SNP P values were adjusted for the number of transmission models, the number of SNPs tested per candidate gene, and their intragenic correlation. DRD2, SLC6A3 and NR4A2 SNPs with adjusted P values < 0.10 were considered sufficiently noteworthy to justify further genetic, bioinformatic and literature analyses. Each independent signal among the top-ranked SNPs accounted for ~1% of the FTND variance in this sample. The DRD2 SNP appears to represent a novel association with nicotine dependence. The SLC6A3 SNPs have previously been shown to be associated with SLC6A3 transcription or dopamine transporter density in vitro, in vivo and ex vivo. Analysis of SLC6A3 and NR4A2 SNPs identified a statistically significant gene-gene interaction (P=0.001), consistent with in vitro evidence that the NR4A2 protein product (NURR1) regulates SLC6A3 transcription. A community cohort of N=175 multiplex ever smoking pedigrees (N=423 ever smokers) provided nominal evidence for association with the FTND at these top ranked SNPs, uncorrected for multiple comparisons.
doi:10.1038/npp.2009.52
PMCID: PMC3558036  PMID: 19494806
dopamine transporter; Fagerström Test for Nicotine Dependence; single nucleotide polymorphism; candidate gene association scan; gene-gene interaction
9.  Association of the Calcyon Neuron-Specific Vesicular Protein Gene (CALY) With Adolescent Smoking Initiation in China and California 
American Journal of Epidemiology  2011;173(9):1039-1048.
Although previous investigations have indicated a role for genetic factors in smoking initiation, the underlying genetic mechanisms are still unknown. In 2,339 adolescents from a Chinese Han population in the Wuhan Smoking Prevention Trial (Wuhan, China, 1998–1999), the authors explored the association of 57 genes in the dopamine pathway with smoking initiation. Using a conservative approach for declaring significance, positive findings were further examined in an independent sample of 603 Caucasian adolescents followed for up to 10 years as part of the Children's Health Study (Southern California, 1993–2009). The authors identified 1 single nucleotide polymorphism (rs2298122) in the calcyon neuron-specific vesicular protein gene (CALY) that was positively associated with smoking initiation in females (odds ratio = 2.21, 95% confidence interval: 1.49, 3.27; P = 8.4 × 10−5) in the Wuhan Smoking Prevention Trial cohort, and they replicated the association in females from the Children's Health Study cohort (hazard rate ratio = 2.05, 95% confidence interval: 1.27, 3.31; P = 0.003). These results suggest that the CALY gene may influence smoking initiation in adolescents, although the potential roles of underlying psychological characteristics that may be components of the smoking-initiation phenotype, such as impulsivity or novelty-seeking, remain to be explored.
doi:10.1093/aje/kwq471
PMCID: PMC3121219  PMID: 21415033
adolescent; dopamine; genetic association studies; smoking
10.  Dose reduction in CT using bismuth shielding: measurements and Monte Carlo simulations 
Radiation Protection Dosimetry  2009;138(4):382-388.
In this research, using direct measurements and Monte Carlo calculations, the potential dose reduction achieved by bismuth shielding in computed tomography was evaluated. The patient dose was measured using an ionisation chamber in a polymethylmethacrylate (PMMA) phantom that had five measurement points at the centre and periphery. Simulations were performed using the MCNPX code. For both the bare and the bismuth-shielded phantom, the differences of dose values between experiment and simulation were within 9 %. The dose reductions due to the bismuth shielding were 1.2–55 % depending on the measurement points, X-ray tube voltage and the type of shielding. The amount of dose reduction was significant for the positions covered by the bismuth shielding (34 − 46 % for head and 41 − 55 % for body phantom on average) and negligible for other peripheral positions. The artefact on the reconstructed images were minimal when the distance between the shielding and the organs was >1 cm, and hence the shielding should be selectively located to protect critical organs such as the eye lens, thyroid and breast. The simulation results using the PMMA phantom was compared with those using a realistically voxelised phantom (KTMAN-2). For eye and breast, the simulation results using the PMMA and KTMAN-2 phantoms were similar with each other, while for thyroid the simulation results were different due to the discrepancy of locations and the sizes of the phantoms. The dose reductions achieved by bismuth and lead shielding were compared with each other and the results showed that the difference of the dose reductions achieved by the two materials was less than 2–3 %.
doi:10.1093/rpd/ncp278
PMCID: PMC3878978  PMID: 19959602

Results 1-10 (10)