Narcotics information management system in South Korea: system development and innovation.

BACKGROUND: As the misuse and abuse of medical narcotics are increasing in South Korea, an information system for the integrated information management of medical narcotic drugs across the nation is needed. This paper presents the development process of the Narcotics Information Management System (NIMS) for the monitoring of medical narcotics usage and the results of its implementation. METHODS: As the NIMS enforces that all narcotics handlers digitally report all information on handling medical narcotic drugs, the functional requirements of the NIMS have been identified in accordance with the Narcotics Control Act. In addition to the functional requirements, the non-functional requirements of the NIMS have been elicited by major narcotics handlers and their associations. The non-functional requirements include privacy, availability, connectivity, interoperability, and data integrity. The system design with entity-relationship diagrams and its implementation processes have been presented. RESULTS: The NIMS encompasses all narcotic handlers, which comprise exporting, importing, and pharmaceutical companies; wholesalers; hospitals and clinics; and pharmacies, collecting over 120 million cases annually. It enables transparent monitoring throughout the life cycle, from manufacturing, sales, purchase, and disposal of narcotics. As a result, the number of prescriptions for medical narcotics has been reduced by 9.2%. CONCLUSIONS: To the best of our knowledge, the NIMS is the world's first system to manage all information on the total life cycle of medical narcotics, including imports, production, distribution, use, and disposal of drugs. This system has enabled the safety management and monitoring of medical narcotic drugs. Additionally, it provides consistent and transparent information to physicians and patients, leading to the autonomous safety management of narcotics. The successful development of the NIMS can provide guidelines for implementing a narcotics management system in other countries.

Depression risk associated with the use of 5α-reductase inhibitors versus α-blockers: A retrospective cohort study in South Korea.

BACKGROUND: One of the most prescribed treatments for benign prostatic hyperplasia (BPH) is 5α-reductase inhibitors (5ARI). Europe experienced recent safety issues involving 5ARI and depression symptoms, with similar findings being seen in Western countries. The South Korea has updated the drug label in accordance with European recommendations, but the relevant evidence was insufficient. This study compared the use of 5ARI versus α-blocker (AB) as a treatment for BPH and related risks of depression to provide evidence based on the Korean population. METHODS: This was a retrospective cohort study using South Korea's Health Insurance Review & Assessment Service claim data from 2011 to 2017. New patients diagnosed in men with BPH and taking medications that contained either 5ARI or AB between July 1, 2013, and June 30, 2015, were included (n = 1,461 5ARI; n = 18,650 AB). The primary outcome was depression defined per the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10: F32-34, F38, F412, F432). Logistic regression was used to implement 1:1 propensity score (PS) matching of patients taking 5ARI to those taking AB to adjust for confounding. Cox proportional hazard models were used to compare the risk of depression associated with 5ARI versus AB. RESULTS: Balance in baseline characteristics between the treatment groups were achieved within PS matched pairs (1,461 pairs). Compared to the AB medication group, the 5ARI group had lower depression (HR: 0.69, 95% CI: [0.51-0.92]). However, we could not find a clinically relevant, statistical difference after PS matching (HR: 0.91, 95% CI: [0.61-1.36]). CONCLUSIONS: The risk of depression associated with 5ARI was not meaningfully different from AB in Korea, which suggests that medical officials should provide the most appropriate medication for BPH patients by considering both treatment benefits and depression risk.

Risk of aortic aneurysm and aortic dissection with the use of fluoroquinolones in Korea: a nested case-control study.

BACKGROUND: Recent studies have raised concern about the association of fluoroquinolones with an increased risk of aortic aneurysm and aortic dissection. We aimed to evaluate such risk in a Korean population. METHODS: We conducted a nested case-control study using data from the National Health Insurance Service collected from 2013 to 2017 in Korea. The study cohort included patients older than 40 years and excluded patients who had used fluoroquinolones or been diagnosed with aortic aneurysm, aortic dissection, or related diseases 1 year prior to the cohort entry date. We randomly matched four controls in the risk set with each case of aortic aneurysm and aortic dissection (same sex, age, and cohort entry date). We assessed the risk of aortic aneurysm and aortic dissection from fluoroquinolones and adjusted for potential confounders using a conditional logistic regression model. RESULTS: A total of 29,638 aortic aneurysm and aortic dissection patients were identified between 2014 and 2017. The use of fluoroquinolones within a year was associated with a 10% increased risk of aortic aneurysm and aortic dissection (adjusted odds ratio: 1.10, 95% CI 1.07-1.14, p < 0.05) compared with nonusers. The risk was higher in patients who had used fluoroquinolones within 60 days (adjusted odds ratio: 1.53, 95% CI 1.46-1.62, p < 0.05). The risk of aortic aneurysm and aortic dissection positively correlated with the cumulative dose and duration of fluoroquinolone therapy (p < 0.001). CONCLUSIONS: Our study provides real-world evidence of the risk of aortic aneurysm and aortic dissection from fluoroquinolones in Korea. Patients and medical professionals should be aware that fluoroquinolones can increase the risk of aortic aneurysm and aortic dissection, which may be acerbated by high dosage and duration of use.

Risk of genital and urinary tract infections associated with SGLT-2 inhibitors as an add-on therapy to metformin in patients with type 2 diabetes mellitus: A retrospective cohort study in Korea.

Sodium-glucose cotransporter-2 (SGLT-2) inhibitors are antidiabetic drugs with associated safety concerns regarding the risk of genital and urinary tract infections. This study assessed the risk of genital and urinary tract infections associated with prescription of SGLT-2 inhibitors as an add-on therapy to metformin in patients with type 2 diabetes mellitus (T2DM) compared to dipeptidyl peptidase-4 (DPP-4) inhibitors, sulfonylurea (SU), and thiazolidinedione (TZD). We conducted a retrospective cohort study using the NHIS-National Health Insurance-Database in Korea from 2014 to 2017. Patients aged ≥19 years and those diagnosed with T2DM prior to drug prescription were enrolled. The outcomes were genital and urinary tract infections. Analysis was performed using Cox's proportional hazard model following 1:1 propensity score matching to calculate the hazard ratio (HR) with a 95% confidence interval (CI). Among the 107 131 patients included in the study, a total of 7738, 7145, and 2175 patients were assigned to the DPP-4 inhibitors, SU, and TZD comparator groups, using the propensity score (PS) of each comparator based on 7741 people in the assessed drug SGLT-2 inhibitor group. SGLT-2 inhibitors were associated with a higher risk of genital infections than DPP-4 inhibitors (HR: 2.39, 95% CI: 2.07-2.76), SU (HR: 3.23, 95% CI: 2.73-3.81), and TZD (HR: 3.23, 95% CI: 2.35-4.44), as an add-on therapy to metformin. Similar results were observed for the risk of urinary tract infections. In conclusion, SGLT-2 inhibitors are significantly associated with a higher risk of genital and urinary tract infections compared to DPP-4 inhibitors, SU, and TZD.

Risk Management for the 21st Century: Current Status and Future Needs.

Global adoption of risk management principles outlined in the International Conference on Harmonisation (ICH) E2E guideline and the Council for International Organizations of Medical Sciences (CIOMS) Working Group VI guidance introduced greater proactivity and consistency into the practice of pharmacovigilance and benefit-risk management throughout the lifecycle of a drug. However, following the release of these guidelines there have been important advances in the science and practice of risk minimisation itself, especially in terms of how risk minimisation measures (RMMs) are designed, implemented, disseminated and evaluated for effectiveness in real-world healthcare settings. In this article, we describe how the field of design, implementation, dissemination and evaluation of RMMs has advanced in recent years while highlighting current areas of challenge and possible solutions. Where possible we cite global examples to demonstrate how evidence-based approaches have informed the development of RMMs. In this context, while taking into consideration local healthcare system policies and national legislations, we conclude with a call for a global effort to harmonise certain areas that focus on, but are not limited to, standardising certain terms and definitions, consistent application of robust methodologies, and outline of best practices for risk minimisation design, implementation, and dissemination.

Clinical and psychological characteristics of propofol abusers in Korea: a survey of propofol abuse in 38, non-healthcare professionals.

BACKGROUND: The aim of this study is to investigate the characteristics of propofol abuse based on the results of a survey analysis of abusers among non-healthcare professionals in Korea. METHODS: Thirty-eight propofol abusers were questioned between October and December 2010, and were enrolled and voluntarily participated in a structured survey consisting of an interview and completing a previously prepared questionnaire. The questionnaire was divided into three distinct parts: part 1 dealt with the history of propofol abuse; part 2 highlighted the problems caused by propofol abuse; and part 3 enquired regarding demographics of abusers. RESULTS: Thirty-one (81.6%) of the 38 interviewees abused propofol for more than one year. During the last 12 months, 34 (89.0%) received propofol at two or three times a week. The minimum and maximum amounts of propofol (median, range) administered each time were 500 (100, 1000) and 2000 (500, 4000) mg, respectively. Stress relief and the maintenance of a sense of well-being were quoted the most important reasons for the first-time administration of propofol and its subsequent abuse, respectively. The majority of abusers (36.0, 97.3%) reported a sense of pleasure or euphoria at the time of their propofol injection. Withdrawal symptoms occurred in five abusers (13.2%). Thirteen (36.1%) reported disruptions in their work life. None of the respondents had previously admitted to and or reported abuse of any other controlled substances. CONCLUSIONS: These results provided reference data for the regulation of propofol in Korea as a controlled substance and may also be of interest to international agencies in other countries.

The Expression of AGO2 and DGCR8 in Idiopathic Sudden Sensorineural Hearing Loss.

OBJECTIVES: The microRNAs have been implicated in the development and function of the inner ear, especially in contribution to hearing. However, the impact of idiopathic sudden sensorineural hearing loss (SSNHL) on expression of miRNA biogenesis-related components has not been established. To investigate the regulations of microRNA (miRNA) biogenesis-related components, argonaute 2 (AGO2) and DiGeorge syndrome critical region gene 8 (DGCR8) mRNA expression in SSNHL and to evaluate the value of clinical parameters on their expression. METHODS: Thirty-seven patients diagnosed with SSNHL and fifty-one healthy volunteers were included in this study. We measured mRNA expression levels of AGO2 and DGCR8 in whole blood cells but erythrocytes of patients with SSNHL and controls, using reverse transcription and real-time polymerase chain reaction analysis. RESULTS: The mRNA expression level of AGO2 is upregulated in SSNHL. The expression level of AGO2 was significantly correlated with that of DGCR8 in both patients with SSNHL and controls. Expression level of AGO2 in SSNHL was correlated with white blood cell counts. CONCLUSION: This study demonstrated for the first time that the AGO2 mRNA expression level was upregulated in SSNHL, suggesting its important role in pathobiology of SSNHL development.

Possibility of CTX-M-14 Gene Transfer from Shigella sonnei to a Commensal Escherichia coli Strain of the Gastroenteritis Microbiome.

OBJECTIVES: To investigated whether the CTX-M-14 gene could be transferred from a clinical Shigella sonnei strain to commensal Escherichia coli strain in the gastroenteritis microbiome. METHODS: E. coli strains were isolated from 30 stool samples of S. sonnei infected students in a gastroenteritis outbreak in 2004 and were characterized by antibiotic resistance analysis, in vitro conjugation and in vivo transfer of CTX-M-14 gene and molecular assays. RESULTS: One strain of Escherichia coli that had high levels of resistance to cefotaxime was isolated from a patient infected with S. sonnei. Isoelectric focusing showed that the E. coli and S. sonnei strains produced a ß-lactamase with an isoelectric point of 8.1. Moreover, polymerase chain reaction analysis indicated that both strains possessed the same DNA sequences for CTX-M-14. The results of in vitro and in vivo conjugation showed that the efficiency of CTX-M-14 transfer from S. sonnei to E. coli was similar to CTX-M-14 transfer between E. coli strains. CONCLUSION: The data suggest that the acquisition of the extended-spectrum ß-lactamases gene by pathogenic bacteria in the human intestinal tract to commensal microbiome bacteria can cause serious infectious diseases.

Characterization of CTX-M-type extended-spectrum beta-lactamase-producing diarrheagenic Escherichia coli isolates in the Republic of Korea during 2008-2011.

To characterize the extended-spectrum beta-lactamases (ESBLs) in diarrheagenic Escherichia coli from Korea in 2008-2011, we screened seven enterotoxigenic E. coli (ETEC) and one enteroaggregative E. coli (EAEC) that produce ESBLs from a nationwide survey. All eight isolates produced CTX-M-type ESBLs, including CTX-M-12 (n = 4), CTX-M-14 (n = 2), and CTX-M-15 (n = 2). PCR-based replicon typing indicated that the blaCTX-M-12 genes of four ETEC isolates were carried on a conjugative IncF plasmid, whereas the blaCTX-M-14 of one EAEC was located on an IncK plasmid. This is the first report of the occurrence of blaCTX-M genes in clinical isolates of EAEC in Korea. The ESBL-producing isolates were shown to be different based on pulsed-field gel electrophoresis and multilocus sequence typing, whereas the four isolates with CTX-M-12 were clonally related. These observations raise an alarm for the spread of plasmid-mediated resistance to ESBL among diarrheagenic E. coli.

Comprehensive variant screening of the UGT gene family.

PURPOSE: UGT1A1, UGT2B7, and UGT2B15 are well-known pharmacogenes that belong to the uridine diphosphate glucuronyltransferase gene family. For personalized drug treatment, it is important to study differences in the frequency of core markers across various ethnic groups. Accordingly, we screened single nucleotide polymorphisms (SNPs) of these three genes and analyzed differences in their frequency among five ethnic groups, as well as attempted to predict the function of novel SNPs. MATERIALS AND METHODS: We directly sequenced 288 subjects consisting of 96 Korean, 48 Japanese, 48 Han Chinese, 48 African American, and 48 European American subjects. Subsequently, we analyzed genetic variability, linkage disequilibrium (LD) structures and ethnic differences for each gene. We also conducted in silico analysis to predict the function of novel SNPs. RESULTS: A total of 87 SNPs were detected, with seven pharmacogenetic core SNPs and 31 novel SNPs. We observed that the frequencies of UGT1A1 *6 (rs4148323), UGT1A1 *60 (rs4124874), UGT1A1 *93 (rs10929302), UGT2B7 *2 (rs7439366), a part of UGT2B7 *3 (rs12233719), and UGT2B15 *2 (rs1902023) were different between Asian and other ethnic groups. Additional in silico analysis results showed that two novel promoter SNPs of UGT1A1 -690G>A and -689A>C were found to potentially change transcription factor binding sites. Moreover, 673G>A (UGT2B7), 2552T>C, and 23269C>T (both SNPs from UGT2B15) changed amino acid properties, which could cause structural deformation. CONCLUSION: Findings from the present study would be valuable for further studies on pharmacogenetic studies of personalized medicine and drug response.

Screening of dihydropyrimidine dehydrogenase genetic variants by direct sequencing in different ethnic groups.

Dihydropyrimidine dehydrogenase (DPYD) is an enzyme that regulates the rate-limiting step in pyrimidine metabolism, especially catabolism of fluorouracil, a chemotherapeutic agent for cancer. In order to determine the genetic distribution of DPYD, we directly sequenced 288 subjects from five ethnic groups (96 Koreans, 48 Japanese, 48 Han Chinese, 48 African Americans, and 48 European Americans). As a result, 56 polymorphisms were observed, including 6 core polymorphisms and 18 novel polymorphisms. Allele frequencies were nearly the same across the Asian populations, Korean, Han Chinese and Japanese, whereas several SNPs showed different genetic distributions between Asians and other ethnic populations (African American and European American). Additional in silico analysis was performed to predict the function of novel SNPs. One nonsynonymous SNP (+199381A > G, Asn151Asp) was predicted to change its polarity of amino acid (Asn, neutral to Asp, negative). These findings would be valuable for further research, including pharmacogenetic and drug responses studies.

Isolation and structural characterisation of a propoxyphenyl-linked thiohomosildenafil analogue found in a herbal product.

A propoxyphenyl-linked thiohomosildenafil analogue, one of the sildenafil analogues, was found in an herbal product. It was isolated by semi-preparative high-performance liquid chromatography (HPLC). The structure was established based on a comparison of chromatographic and spectroscopic behaviour with other sildenafil analogues using HPLC with diode array detection, quadrupole time-of-flight mass spectrometry (Q-TOF/MS), and nuclear magnetic resonance (NMR) spectroscopy. The HPLC analysis showed separation from known sildenafil analogues with a similar chromatographic retention time. An [M + H](+) ion at m/z 519.22 was detected by mass spectrometry corresponding to an empirical formula of C24H34N6O3S2. The structure was similar to that of thiohomosildenafil, except that the ethoxy group attached to the phenyl ring was substituted for a propoxy group. It was assigned as 5-[2-propoxy-5-(4-ethylpiperazin-4-ylsulfonyl)phenyl]-3-methyl-1-n-propyl-4,5,dihydro-1H-pyrazole[7,1,d]pyrimidin-4-thione and named as propoxyphenyl-thiohomosildenafil because the structure was considerably similar to thiohomosildenafil.

Simultaneous determination of 38 phosphodiestrase-5 inhibitors in illicit erectile dysfunction products by liquid chromatography-electrospray ionization-tandem mass spectrometry.

This paper describes the development and validation of simultaneous analytical method for 38 compounds, sildenafil, tadalafil, vardenafil and their analogues in illicit erectile dysfunction (ED) products by the liquid chromatography-electrospray ionization-tandem mass method (LC-ESI-MS/MS). Chromatographic separation was performed on a C18 reversed-phase column using a gradient of solvent A: aqueous 2 mM ammonium formate solution and solvent B: acetonitrile (ACN). All components were monitored under time-scheduled multiple reaction monitoring (MRM) mode. The limits of detection (LOD) ranged from 0.004 ng/ml to 0.455 ng/ml and the limits of quantification (LOQ) ranged from 0.012 ng/ml to 1.5 ng/ml. Calibration curves were linear with correlation coefficients over 0.9991. Mean recoveries ranged from 73.6% to 111.3%, and relative standard deviation (RSD) was less than 10%. The intra- and inter-day precision ranged from 0.2% to 16.3% and from 0.2% to 17.0%, respectively. The proposed method was applied to investigate the 52 illicit ED products.

Isolation and identification of a sibutramine analogue adulterated in slimming dietary supplements.

A suspected sibutramine analogue was detected in a slimming functional food by an ultra performance liquid chromatography-electrospray ionisation-time of flight mass spectrometry (UPLC-ESI-TOF/MS) method. The ultraviolet (UV) spectrum of this suspected compound showed close similarity to that of sibutramine. The sample was extracted with 70% MeOH and isolated by semi-preparative column chromatography. The structure of this compound was identified by spectroscopic analyses (nuclear magnetic resonance [NMR] technique, mass and tandem mass etc.). The structure of the unknown compound was demonstrated to be [(±)-dimethyl-1-[1-(3,4-dichlorophenyl)cyclobutyl]-N,N,3-trimethylbutan-1-amine (molecular formula C17H25NCl2) and named as chloro-sibutramine. Compared with sibutramine, it has one more chlorine atom than the 3-cholorophenyl group so was switched to 3,4-dichlorophenyl. Until now, chloro-sibutramine was isolated for the first time from the undeclared ingredient included in dietary supplements. Although the safety of chloro-sibutramine is unknown, there is a potential health risk to consumers because of a similar skeleton to sibutramine. For public health, this sibutramine analogue has been included in the inspection list of illegal adulterants in Korea.

Identification of a new tadalafil analogue found in a dietary supplement.

A new tadalafil analogue, acetaminotadalafil, was detected by HPLC in a bulk powder that is being used as an ingredient formanufacturing dietary supplements. The analogue was isolated by semi-preparative HPLC. A chemical structure of the new compound was elucidated by HPLC, LC-quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS), nuclear magnetic resonance (NMR), infrared (IR) and circular dichroism (CD) spectroscopy. The compound was identified as an acetylatedcompound of aminotadalafil. The structure of the previous unknown compound was confirmed as (6R,12aR)-2-acetamino-6-(1,3-benzodioxol-5-yl)-2,3,6,7,12,12a-hexahydro-pyrazino[1',2':1,6]pyrido[3,4-b]indole-1,4-dione and named as acetaminotadalafil.

In vitro evaluation of biomarkers for cisplatin-induced nephrotoxicity using HK-2 human kidney epithelial cells.

The non-animal in vitro test methods, especially for assessment of kidney toxicity, have become invaluable tools due to the target organ-selective nature of many nephrotoxic xenobiotics. In vitro evaluation of biomarkers for nephrotoxicity assessment using human cell lines, which can provide more reliable information for toxicological risk evaluation in humans than animal cells, has not been well established to date. The present study investigated the potential use of biomarkers for cisplatin-induced nephrotoxicity assessment in vitro using HK-2 cells derived from human kidney proximal tubule epithelial cells. Cisplatin induced apoptosis of HK-2 cells in which down-regulation of Bcl-2 and activation of caspase-3 were possibly involved. We investigated the effect of cisplatin on the protein levels of kidney injury molecule (KIM)-1, clusterin, calbindin, tissue inhibitor of metalloproteinase (TIMP)-1, cystatin C (CysC), ß2-microglobulin (ß2-M) and neutrophil gelatinase associated lipocalin (NGAL), which have been recently identified as in vivo biomarkers of nephrotoxicity. The protein levels of KIM-1, calbindin and TIMP-1 were significantly increased in the conditioned media of HK-2 cells treated with cisplatin, while ß2-M, CysC, NGAL and clusterin were not affected by cisplatin treatment. The mRNA levels of KIM-1, calbindin and TIMP-1 were increased by cisplatin, indicating that cisplatin-induced up-regulation involves transcriptional activation. The levels of KIM-1, calbindin and TIMP-1 were significantly increased in urine of cisplatin-treated rats, providing in vivo validation of the in vitro results. Taken together, our results clearly demonstrate that among the known in vivo nephrotoxic biomarkers, KIM-1, calbindin and TIMP-1 can be effectively used as in vitro biomarkers for cisplatin-induced nephrotoxicity using a HK-2 human kidney cell system.

Screening of Genetic Polymorphisms of CYP3A4 and CYP3A5 Genes.

Given the CYP3A4 and CYP3A5's impact on the efficacy of drugs, the genetic backgrounds of individuals and populations are regarded as an important factor to be considered in the prescription of personalized medicine. However, genetic studies with Korean population are relatively scarce compared to those with other populations. In this study, we aimed to identify CYP3A4/5 polymorphisms and compare the genotype distributions among five ethnicities. To identify CYP3A4/5 SNPs, we first performed direct sequencing with 288 DNA samples which consisted of 96 Koreans, 48 European-Americans, 48 African-Americans, 48 Han Chinese, and 48 Japanese. The direct sequencing identified 15 novel SNPs, as well as 42 known polymorphisms. We defined the genotype distributions, and compared the allele frequencies among five ethnicities. The results showed that minor allele frequencies of Korean population were similar with those of the Japanese and Han Chinese populations, whereas there were distinct differences from European-Americans or African-Americans. Among the pharmacogenetic markers, frequencies of CYP3A4*1B (rs2740574) and CYP3A5*3C (rs776742) in Asian groups were different from those in other populations. In addition, minor allele frequency of CYP3A4*18 (rs28371759) was the highest in Korean population. Additional in silico analysis predicted that two novel non-synonymous SNPs in CYP3A5 (+27256C>T, P389S and +31546T>G, I488S) could alter protein structure. The frequency distributions of the identified polymorphisms in the present study may contribute to the expansion of pharmacogenetic knowledge.

Evaluation of in vitro screening system for estrogenicity: comparison of stably transfected human estrogen receptor-α transcriptional activation (OECD TG455) assay and estrogen receptor (ER) binding assay.

The estrogenic activity of industrial chemicals, di(2-ethylhexyl) phthalate (DEHP), di(n-butyl) phthalate (DBP), benzylbutyl phthalate (BBP), diethyl phthalate (DEP), tetrabromobisphenol A (TBBPA), bisphenol A (BPA), and nonylphenol (NP), was compared using OECD test guideline 455(TG455), stably transfected transcriptional activation (STTA) and estrogen receptor (ER) binding assays. The estrogenic activity of BBP, BPA and NP were approximately 180,000-fold (PC(50), 4.32 x 10(-6 )M), 5,000-fold (PC(50), 1.26 x 10(-7) M) and 120,000-fold (PC(50), 2.92 x 10(-6 )M) less than 17ß-estradiol (PC(50), 2.43 x 10(-11)M), whereas DEHP, DBP and DEP did not show any estrogenicity activity in the STTA assay. Moreover, binding affinities to human ERα of BBP, BPA, and NP were approximately 200,000-fold (IC(50), 4.91 x 10(-4) M), 8000-fold (IC(50), 1.92 x 10(-5) M) and 1400-fold (IC(50), 3.34 x 10(-6) M) less than 17ß-estradiol (IC(50), 2.45 x 10(-9) M) in competitive human ERα binding assay. The relative potencies of STTA assay were very similar to ER binding, E-screen, and Yeast screening assays. Therefore, our results suggested that OECD test guideline TG455 may be useful as a screening test for potential endocrine disruptors.

Comparisons of polybrominated diphenyl ethers levels in paired South Korean cord blood, maternal blood, and breast milk samples.

Polybrominated diphenyl ethers (PBDEs), commonly used flame retardants, have been reported as potential endocrine disruptor and neurodevelopmental toxicants, thus giving rise to the public health concern. The goal of this study was to investigate the relationship between umbilical cord blood, maternal blood, and breast milk concentrations of PBDEs in South Korean. We assessed PBDE levels in paired samples of umbilical cord blood, maternal blood, and breast milk. The levels of seven PBDE congeners were measured in 21 paired samples collected from the Cheil Woman's Hospital (Seoul, Korea) in 2008. We also measured thyroid hormones levels in maternal and cord blood to assess the association between PBDEs exposure and thyroid hormone levels. However, there was no correlation between serum thyroxin (T4) and total PBDEs concentrations. The total PBDEs concentrations in the umbilical cord blood, maternal blood, and breast milk were 10.7±5.1 ng g(-1) lipid, 7.7±4.2 ng g(-1) lipid, and 3.0±1.8 ng g(-1) lipid, respectively. The ranges of total PBDE concentrations observed were 2.28-30.94 ng g(-1) lipid in umbilical cord blood, 1.8-17.66 ng g(-1) lipid in maternal blood, and 1.08-8.66 ng g(-1) lipid in breast milk. BDE-47 (45-73% of total PBDEs) was observed to be present dominantly in all samples, followed by BDE-153. A strong correlation was found for major BDE-congeners between breast milk and cord blood or maternal blood and cord blood samples. The measurement of PBDEs concentrations in maternal blood or breast milk may help to determine the concentration of PBDEs in infant.

Effects of nortriptyline on QT prolongation: a safety pharmacology study.

Nortriptyline, a second-generation tricyclic antidepressant, is an active metabolite of amitriptyline. Amitriptyline induces QT prolongation and torsades de pointes (TdP), which causes sudden death. We studied the cardiovascular safety of nortriptyline, including QT prolongation risk. We examined the effects of nortriptyline on the cardiovascular system in vivo and in vitro in accordance with the ICH-S7B guideline. We tested its effect on QT interval in conscious telemetered dogs. We also performed in vitro electrophysiological studies on hERG tail currents using stably transfected human embryonic kidney 293 (HEK293) cells. Action potential parameters were studied in isolated rabbit purkinje fibers. Nortriptyline dose-dependently blocked hERG current, with a tail IC(50) value of 2.20 ± 0.09 µM (n = 4). In the APD assay, total amplitude, Vmax, and resting membrane potential were not significantly changed by 1 µM nortriptyline, but nortriptyline at 0.3 and 1 µM shortened APD(50) and APD(90). Nortriptyline did not affect QTcV at 2 or 6 mg/kg, but slightly increased QTcV at 20 mg/kg. In conclusion, it is unlikely that nortriptyline affects the ventricular repolarization process at therapeutic dosages.