Safety and Efficacy of Everolimus-Eluting Bioresorbable Vascular Scaffold Versus Second-Generation Drug-Eluting Stents in Real-World Practice

Background@#The risk of device thrombosis and device-oriented clinical outcomes with bioresorbable vascular scaffold (BVS) was reported to be significantly higher than with contemporary drug-eluting stents (DESs). However, optimal device implantation may improve clinical outcomes in patients receiving BVS. The current study evaluated mid-term safety and efficacy of Absorb BVS with meticulous device optimization under intravascular imaging guidance. @*Methods@#The SMART-REWARD and PERSPECTIVE-PCI registries in Korea prospectively enrolled 390 patients with BVS and 675 patients with DES, respectively. The primary endpoint was target vessel failure (TVF) at 2 years and the secondary major endpoint was patientoriented composite outcome (POCO) at 2 years. @*Results@#Patient-level pooled analysis evaluated 1,003 patients (377 patients with BVS and 626 patients with DES). Mean scaffold diameter per lesion was 3.24 ± 0.30 mm in BVS group.Most BVSs were implanted with pre-dilatation (90.9%), intravascular imaging guidance (74.9%), and post-dilatation (73.1%) at proximal to mid segment (81.9%) in target vessel.Patients treated with BVS showed comparable risks of 2-year TVF (2.9% vs. 3.7%, adjusted hazard ratio [HR], 1.283, 95% confidence interval [CI], 0.487–3.378, P = 0.615) and 2-year POCO (4.5% vs. 5.9%, adjusted HR, 1.413, 95% CI, 0.663–3.012,P = 0.370) than those with DES. The rate of 2-year definite or probable device thrombosis (0.3% vs. 0.5%, P = 0.424) was also similar. The sensitivity analyses consistently showed comparable risk of TVF and POCO between the 2 groups. @*Conclusion@#With meticulous device optimization under imaging guidance and avoidance of implantation in small vessels, BVS showed comparable risks of 2-year TVF and device thrombosis with DES.

Novel 18ß-glycyrrhetinic acid derivatives as a Two-in-One agent with potent antimicrobial and anti-inflammatory activity.

18ß-glycyrrhetinic acid (GA) is a well-known natural compound of oleanane-type triterpene and is found possessing antimicrobial and anti-inflammatory properties. Nonetheless, its relatively low bioactivity restricts its potential in pharmaceutical applications. To maximize the potential use of this natural herbal compound as antimicrobial and anti-inflammatory agents, the rational modification of GA to enhance its pharmacological activity with low toxicity and to understand the mechanism of action is critically essential. We reported herein the design and synthesis of a series of new GA derivatives. The antimicrobial activities of these new compounds were evaluated by inhibition zone test and minimum inhibitory concentration (MIC) assay. In addition, the anti-inflammatory activity was evaluated by LPS induced BV2 cells inflammation model and 12-O-tetradecanoyl phorbol-13-acetate (TPA) induced ear inflammation mice model. It was found that the derivatives functionalized with a di-substituted phenyl group at the 2-position of GA generally displayed high antimicrobial activity against Gram-positive bacteria (MIC down to 2.5 µM) and potent anti-inflammatory effects (inhibition of NO production up to 55%, comparable to dexamethasone). The in vitro and in vivo results also showed that GA-O-02 and GA-O-06 exert their anti-inflammatory activities through downregulation of NO, pro-inflammatory cytokines and chemokines (IL-1ß, IL-6, IL-12, TNF-α, MCP-1 and MIP-1α) and upregulation of anti-inflammatory cytokines (IL-10). The anti-inflammatory mechanism may involve the inhibition of NF-κB, MAPKs and PI3K/Akt related inflammatory signaling pathways and activation of Nrf2/HO-1 signaling pathway. The results demonstrated that GA-O-02 and GA-O-06 possess great application potential as potent antimicrobial and anti-inflammatory agents.

A human antibody that broadly neutralizes betacoronaviruses protects against SARS-CoV-2 by blocking the fusion machinery

The repeated spillovers of {beta}-coronaviruses in humans along with the rapid emergence of SARS-CoV-2 escape variants highlight the need to develop broad coronavirus therapeutics and vaccines. Five monoclonal antibodies (mAbs) were isolated from COVID-19 convalescent individuals and found to cross-react with multiple {beta}-coronavirus spike (S) glycoproteins by targeting the stem helix. One of these mAbs, S2P6, cross-reacts with more than twenty human and animal {beta}-coronavirus S glycoproteins and broadly neutralizes SARS-CoV-2 and pseudotyped viruses from the sarbecovirus, merbecovirus and embecovirus subgenera. Structural and functional studies delineate the molecular basis of S2P6 cross-reactivity and broad neutralization and indicate that this mAb blocks viral entry by inhibiting membrane fusion. S2P6 protects hamsters challenged with SARS-CoV-2 (including the B.1.351 variant of concern) through direct viral neutralization and Fc-mediated effector functions. Serological and B cell repertoire analyses indicate that antibodies targeting the stem helix are found in some convalescent donors and vaccinees but are predominantly of narrow specificity. Germline reversion of the identified cross-reactive mAbs revealed that their unmutated ancestors are specific for the endemic OC43 or HKU1 viruses and acquired enhanced affinity and breadth through somatic mutations. These data demonstrate that conserved epitopes in the coronavirus fusion machinery can be targeted by protective antibodies and provide a framework for structure-guided design of pan-{beta}-coronavirus vaccines eliciting broad protection.

Atrial thrombi in elective patients considered for atrial fibrillation rhythm control: Risk factors and prognostic value.

The prognostic value of atrial thrombi (AT) among elective patients with atrial fibrillation (AF) referred for a rhythm control strategy is unclear. In this study, clinical variables were correlated with the presence of AT and long term survival among 205 patients submitted to transesophageal echocardiography before elective AF cardioversion or ablation. Atrial thrombi were present in 7.8% of cases and were significantly associated with reduced survival. Obesity was the only independent clinical predictor of AT [OR 4.27 (1.15-15.79), p = 0.03]. In patients with AF, AT appear to be associated with adverse outcomes, possibly indicating more advanced atrial cardiomyopathy.

HYPER: Group testing via hypergraph factorization applied to COVID-19

Large scale screening is a critical tool in the life sciences, but is often limited by reagents, samples, or cost. An important challenge in screening has recently manifested in the ongoing effort to achieve widespread testing for individuals with SARS-CoV-2 infection in the face of substantial resource constraints. Group testing methods utilize constrained testing resources more efficiently by pooling specimens together, potentially allowing larger populations to be screened with fewer tests. A key challenge in group testing is to design an effective pooling strategy. The global nature of the ongoing pandemic calls for something simple (to aid implementation) and flexible (to tailor for settings with differing needs) that remains efficient. Here we propose HYPER, a new group testing method based on hypergraph factorizations. We provide theoretical characterizations under a general statistical model, and exhaustively evaluate HYPER and proposed alternatives for SARS-CoV-2 screening under realistic simulations of epidemic spread and within-host viral kinetics. We demonstrate that HYPER performs at least as well as other methods in scenarios that are well-suited to each method, while outperforming those methods across a broad range of resource-constrained environments, being more flexible and simple in design, and taking no expertise to implement. An online tool to implement these designs in the lab is available at http://hyper.covid19-analysis.org.

Oleanolic acid indole derivatives as novel α-glucosidase inhibitors: Synthesis, biological evaluation, and mechanistic analysis.

Research efforts have been directed to the development of oleanolic acid (OA) based α-glucosidase inhibitors and various OA derivatives showed improved anti-α-glucosidase activity. However, the inhibitory effects of indole infused OA derivatives on α-glucosidase is unknown. Herein, we synthesized a series of indole-OA (2a-2o) and -OA methyl ester (3a-3 l) derivatives with various electron withdrawing groups inducted to indole benzene ring and evaluated their anti-α-glucosidase activity. Indole OA derivatives (2a-2o) exhibited superior α-glucosidase inhibitory effects as compared to OA methyl ester derivatives (3a-3l) and OA (with IC50 values of 4.02 µM-5.30 µM v.s. over 10 µM and 5.52 µM, respectively). In addition, mechanistic studies using biochemical (kinetic assay), biophysical (circular dichroism), and computational (docking) methods revealed that OA-indole derivatives (2a and 2f) are mixed type of α-glucosidase inhibitors and their inhibitory effects were attributed to their capacity of forming the ligand-enzyme complex with α-glucosidase enzyme. Findings from this study support that OA indole derivatives are promising α-glucosidase inhibitors as a potential management of diabetes mellitus.

Remdesivir-Ivermectin combination displays synergistic interaction with improved in vitro antiviral activity against SARS-CoV-2

A key element for the prevention and management of COVID-19 is the development of effective therapeutics. Drug combination strategies of repurposed drugs offer several advantages over monotherapies, including the potential to achieve greater efficacy, the potential to increase the therapeutic index of drugs and the potential to reduce the emergence of drug resistance. Here, we report on the in vitro synergistic interaction between two FDA approved drugs, remdesivir and ivermectin resulting in enhanced antiviral activity against SARS-CoV-2. These findings warrant further investigations into the clinical potential of this combination, together with studies to define the underlying mechanism.

Efficient prevalence estimation and infected sample identification with group testing for SARS-CoV-2

Extensive virological testing is central to SARS-CoV-2 containment, but many settings face severe limitations on testing. Group testing offers a way to increase throughput by testing pools of combined samples; however, most proposed designs have not yet addressed key concerns over sensitivity loss and implementation feasibility. Here, we combine a mathematical model of epidemic spread and empirically derived viral kinetics for SARS-CoV-2 infections to identify pooling designs that are robust to changes in prevalence, and to ratify losses in sensitivity against the time course of individual infections. Using this framework, we show that prevalence can be accurately estimated across four orders of magnitude using only a few dozen pooled tests without the need for individual identification. We then exhaustively evaluate the ability of different pooling designs to maximize the number of detected infections under various resource constraints, finding that simple pooling designs can identify up to 20 times as many positives compared to individual testing with a given budget. We illustrate how pooling affects sensitivity and overall detection capacity during an epidemic and on each day post infection, finding that sensitivity loss is mainly attributed to individuals sampled at the end of infection when detection for public health containment has minimal benefit. Crucially, we confirm that our theoretical results can be accurately translated into practice using pooled human nasopharyngeal specimens. Our results show that accounting for variation in sampled viral loads provides a nuanced picture of how pooling affects sensitivity to detect epidemiologically relevant infections. Using simple, practical group testing designs can vastly increase surveillance capabilities in resource-limited settings.

Modelling of Systemic versus Pulmonary Chloroquine Exposure in Man for COVID-19 Dose Selection

Chloroquine has attracted intense attention as a potential clinical candidate for prevention and treatment of COVID-19 based on reports of in-vitro efficacy against SARS-CoV-2. While the pharmacokinetic-pharmacodynamic (PK-PD) relationship of chloroquine is well established for malaria, there is sparse information regarding its dose-effect relationship in the context of COVID-19. Here, we explore the PK-PD relationship of chloroquine for COVID-19 by modelling both achievable systemic and pulmonary drug concentrations. Our data indicate that the standard anti-malarial treatment dose of 25mg/kg over three days does not deliver sufficient systemic drug exposures for the inhibition of viral replication. In contrast, PK predictions of chloroquine in the lungs using in-vivo data or human physiologically-based PK models, suggest that doses as low as 3mg/kg/day for 3 days could deliver exposures that are significantly higher than reported antiviral-EC90s for up to a week. Moreover, if pulmonary exposure is a driver for prevention, simulations show that chronic daily dosing of chloroquine may be unnecessary for prophylaxis purposes. Instead, once weekly doses of 5mg/kg would be sufficient to achieve a continuous cover of therapeutically active pulmonary exposures. These findings reveal a highly compartmentalised distribution of chloroquine in man that may significantly affect its therapeutic potential against COVID-19. The systemic circulation is shown as one site where chloroquine exposure is insufficient to inhibit SARS-CoV-2 replication. However, if therapeutic activity is driven by pulmonary exposure, it should be possible to reduce the chloroquine dose to safe levels. Carefully designed randomized controlled trials are urgently required to address these outstanding issues.

Potent Antimalarial 2-Pyrazolyl Quinolone bc 1 (Qi) Inhibitors with Improved Drug-like Properties.

A series of 2-pyrazolyl quinolones has been designed and synthesized in 5-7 steps to optimize for both in vitro antimalarial potency and various in vitro drug metabolism and pharmacokinetics (DMPK) features. The most potent compounds display no cross-resistance with multidrug resistant parasite strains (W2) compared to drug sensitive strains (3D7), with IC50 (concentration of drug required to achieve half maximal growth suppression) values in the range of 15-33 nM. Furthermore, members of the series retain moderate activity against the atovaquone-resistant parasite isolate (TM90C2B). The described 2-pyrazoyl series displays improved DMPK properties, including improved aqueous solubility compared to previously reported quinolone series and acceptable safety margin through in vitro cytotoxicity assessment. The 2-pyrazolyl quinolones are believed to bind to the ubiquinone-reducing Qi site of the parasite bc 1 complex, which is supported by crystallographic studies of bovine cytochrome bc 1 complex.

Identification and prioritization of novel anti-Wolbachia chemotypes from screening a 10,000-compound diversity library.

Lymphatic filariasis and onchocerciasis are two important neglected tropical diseases (NTDs) that cause severe disability. Control efforts are hindered by the lack of a safe macrofilaricidal drug. Targeting the Wolbachia bacterial endosymbionts in these parasites with doxycycline leads to a macrofilaricidal outcome, but protracted treatment regimens and contraindications restrict its widespread implementation. The Anti-Wolbachia consortium aims to develop improved anti-Wolbachia drugs to overcome these barriers. We describe the first screening of a large, diverse compound library against Wolbachia. This whole-organism screen, streamlined to reduce bottlenecks, produced a hit rate of 0.5%. Chemoinformatic analysis of the top 50 hits led to the identification of six structurally diverse chemotypes, the disclosure of which could offer interesting avenues of investigation to other researchers active in this field. An example of hit-to-lead optimization is described to further demonstrate the potential of developing these high-quality hit series as safe, efficacious, and selective anti-Wolbachia macrofilaricides.

A Comparison of Comorbidity and Psychological Outcomes in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE: The purpose of this study was to compare psychiatric comorbid disorders and psychological outcomes in children and adolescents with Attention-deficit/hyperactivity disorder (ADHD). METHODS: Subjects were divided into a child group (aged under 12 years) and an adolescent group (aged 12 years and above). All subjects were diagnosed with ADHD based on the DSM IV diagnostic criteria using the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Korean Version (K-SADS-PL-K). The K-SADS-PL-K was also used to evaluate those psychiatric disorders comorbid with ADHD. And the Korean version of the Child Behavior Checklist (K-CBCL) was used to examine the subjects' psychological outcomes. RESULTS: The rate of comorbidity in adolescent group was significantly higher than that in the child group. In particular, the adolescent group had a significantly higher ratio of comorbid conduct disorder and mood disorder than the child group. With respect to the predominantly inattentive type and Not Otherwise Specified, the school subscale scores on the K-CBCL for the children were significantly higher than those for the adolescents. CONCLUSION: These results suggest that the psychiatric comorbidity may differ between adolescents and children with ADHD. Therefore when treating adolescents with ADHD, more careful assessment and treatment targeting a range of comorbidities are needed.

Differences of Clinical Characteristics and Phenotypes between Prepubertal- and Adolescent-Onset Bipolar Disorders

The aim of this study is to describe the clinical characteristics of prepubertal- and adolescent-onset bipolar disorder (BD) and to identify any clinical differences between patients with prepubertal- and adolescent-onset BD. We analyzed the clinical records of 53 inpatients with BD. These patients were divided into prepubertal-onset and adolescent-onset groups. We also divided the subjects into narrow, intermediate, and broad phenotypes according to the definitions proposed by Leibenluft and colleagues. Of the total sample, 16 patients (30.2%) were in the prepubertal-onset group and 37 (69.8%) were in the adolescent-onset group. Patients with prepubertal-onset BD were more likely to display an insidious clinical presentation, atypical features, and comorbid psychopathology. And the majority of the subjects, especially in the prepubertal-onset group, were classified under the intermediate and broad phenotypes. These results suggest that the clinical presentation of BD with prepubertal-onset is different from that of adolescent-onset BD. It is inferred that a significant number of patients with prepubertal- and adolescent-onset BD do not meet DSM-IV criteria for mania or hypomania from the results of this study.

Characteristics of Temperament and Character Properties in Adolescents with Internet Addiction Tendency / 신경정신의학

OBJECTIVES: Recent studies have focused on characteristics of adolescents who use internet addictively. Due to many ambiguities in the definitions of internet addiction, it is hard to find a tool for diagnosing internet addiction. In this study, we attempt to identify the temperamental characteristics of adolescents who have addictive internet using patterns by administering a newly developed internet addiction scale based on a psychometric technique and temperament and character inventory (TCI) based on Cloninger's psychobiological model. METHODS: Participants were 566 high school students. 478 students were recruited from high schools, and 88 were selected from internet cafes. We applied the internet addiction scale and TCI. All the students were divided into 3 groups (high risk user group, potential risk user group and normal user group) according to the results of the internet addiction scale. TCI scores were compared and analyzed according to the participants' characteristics. RESULTS: There were significant differences in the distribution of internet user group according to gender. Boys had higher percentage of high risk and potential risk users than girls. When each TCI score was compared according to gender, girls showed significantly higher harm avoidance, reward dependence, cooperativeness scale scores and lower persistence, self-transcendence scale scores than boys. TCI scores were compared among the internet addiction risk user groups. Risky internet users showed lower scores in reward dependence, self-directness and cooperativeness dimensions than normal internet users. CONCLUSION: There was a gender difference in internet addiction risk in this study. These results suggest that adolescents who use internet addictively also have higher tendency of problematic social and interpersonal relationship. These tendencies need to be considered as one of the important aspects of internet addiction. This study shows that assessment of temperament and character in adolescents who have problems related to the internet may be needed for understanding their addiction behaviors and underlying psychopathologies.

The KIDSCREEN-52 Quality of Life Measure for Children and Adolescents (KIDSCREEN-52-HRQOL): Reliability and Validity of the Korean Version

The KIDSCREEN-52 quality-of-life (KIDSCREEN-52-HRQOL) is a relevant, worldwide tool used for assessing the health-related quality of life in children and adolescents. The purpose of this study was to define measurement properties of the Korean version of the KIDSCREEN-52 HRQOL. The original questionnaire was translated following international translation guidelines. Analysis regarding psychometric properties showed that the Cronbach-alpha ranged from 0.77 to 0.95. The correlation coefficient between the PedQL and KIDSCREEN-52 dimensions were high for the assessments of similar constructs. Therefore, the Korean version of the KIDSCREEN-52 was found to be suitable for use in Korean adolescents.

Psychiatric Comorbidity in Korean Children and Adolescents with Attention-Deficit Hyperactivity Disorder: Psychopathology According to Subtype

It is well-known that more than 50% of attention-deficit hyperactivity disorder (ADHD) cases also have comorbid psychiatric disorders. We evaluated the comorbid psychopathology of Korean children and adolescents with ADHD using a standardized diagnostic instrument. The Korean Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version (K-SADS-PL-K) was administered and completed in 105 patients who had been referred to the outpatient and inpatient clinics at the Samsung Medical Center from March 2004 to May 2005. All of the cases were diagnosed as ADHD according to DSM-IV criteria. We analyzed their clinical characteristics and psychiatric comorbidities, and assessed the correlation of any comorbidity with gender, age and ADHD subtype. Among our 105 participants, 70 (66.7%) subjects were diagnosed with combined-type ADHD, 22 (21.0%) were the predominantly inattentive type, only 1 (1.0%) was determined to have the predominantly hyperactive-impulsive type of ADHD, and 12 (11.4%) were classified as not otherwise specified (NOS) ADHD. Eighty (76.2%) subjects had at least one comorbid disorder such as oppositional defiant disorder (n = 53, 50.5%), anxiety disorders (n = 35, 33.3%) and affective disorders (n = 15, 14.3%). Our patients ranged in age from five to 16 years. Among the factors including gender, age, and ADHD subtype, ADHD subtype was the only one significant to comorbidity in our study. The results of this study suggest that psychiatric comorbidity in Korean children with ADHD is similar to the results of previous studies in western countries. Out of all the ADHD subtypes, the combined-type group had a significantly higher ratio of comorbid disorders and psychopathologies.

Prevalence and Correlates of Attention Deficit Hyperactivity Disorder: School-Based Mental Health Services in Seoul / 신경정신의학

OBJECTIVES: To estimate the prevalence and correlates of children who had Attention Deficit Hyperactivity Disorder (ADHD) in Seoul. METHODS: A cross-sectional survey of 2,429 children included in four elementary schools at Seoul. Parents and teachers completed the Korean ADHD Rating Scales (K-ARS) and the Korean version of the Strengths and Difficulties Questionnaire (SDQ-Kr). Child psychiatrists interviewed the children who demonstrated clinically significant scores on K-ARS and SDQ-Kr. Further assessments were conducted with other psychological tests if needed. RESULTS: 1) Of 2,429 children, 158 (6.5%) children had ADHD. 2) Compared to controls, ADHD children showed more frequently male preponderance, more single parent family, lower parental education level, more paternal no employment, poorer sibling relationship, fewer number of friends, and lower ability in language and mathematics. 3) In multivariate analysis, ADHD were associated with boys, single parent family, poor sibling relationship, and low language ability. Our stratified analysis by gender, there were association with single parent family and lower language ability in boys, and poor sibling relationship and lower mathematics ability in girls. CONCLUSION: This study found 6.5% prevalence of ADHD and ADHD were associated with gender, family environment, and academic achievements. Understanding of high-risk children would help in developing an ADHD school mental health program.

Seasonal Variations in Mood and Behavior in Korean High School Students / 수면정신생리

OBJECTIVES: Although many reports have been written on seasonal variations in mood and behavior in foreign countries, few reports have dealt with Korean adolescents, except medical students. The goal of this study was to estimate the frequency of seasonal variations in mood and behavior among Korean high school students. METHODS: A total of 656 high school students living in southeastern Seoul participated in this study. The subjects were investigated with the Korean translated version of the Seasonal Pattern Assessment Questionnaire (SPAQ), and their responses were evaluated for seasonal patterns in mood and behavior change according to Kasper's criteria to make SAD (seasonal affective disorder) or SSAD (subclinical seasonal affective disorder) diagnosis. RESULTS: A total of 565 subjects completed the questionnaire and the responses (M: F=324: 241) were collected and used for analysis. The mean age was 16.73 (SD=0.65) years, and mean global seasonality score 5.88 (SD=4.72). Of the respondents, 413 (73.1%) reported problems related with seasonal changes. Total prevalence rates were 13.6% for SAD, 10.8% for S-SAD. The estimated frequencies were 5.1% for summer SAD, 3.2% for summer S-SAD, 0.5% for winter SAD and 1.1% for winter S-SAD. The prevalence rate of summer SAD or S-SAD was higher than winter SAD or S-SAD. CONCLUSION: The subjects showed a higher prevalence rate of summer type than winter type in SAD or S-SAD. These results were similar to those of other studies carried out in East Asian countries. However, the unpleasant feelings resulting from high temperature and humidity in summer rather than depression may have influenced the results. Therefore, it is necessary to make new SAD criteria of the SPAQ suitable for East Asian countries.

Adjustment of Korean-American physicians in Korea: aspect of personal satisfaction

This study was conducted to assess the psychosocial adjustment of Korean-American physicians in the aspect of personal satisfaction after returning to Korea. A questionnaire was mailed to 72 Korean-American physicians who were practicing medicine in Korea and forty physicians responded. These physicians, typically in their 50s, lived in America for 21-30 years before coming back to Korea. The most frequent motives for them to come back to Korea were giving back to their native country, longing for their native country, filial duty, and suggestions from their colleagues or professors to move back. Eighty percent of them were extremely satisfied or slightly satisfied with their work in Korea, and only 10% are extremely or slightly dissatisfied with their decision to return. Although most of them are content for the time being in Korea, only 12.5% have definite plans to stay in Korea after retirement. The variables that were most significantly related to personal satisfaction of returning to Korea were how well treated at work and how much satisfied with job rather than other factors such as motives for returning, duration of staying in America and in Korea, and family situation.

Korean Standardization of Parent Temperament Questionnaire for Children / 신경정신의학

OBJECTIVES: One of the factors that obstructs active progress of the temperament study in Korea is lack of the standardized assessment tools. Therefore, this study was designed and conducted for the purpose of Korean standardization of "Parental Temperament Questionnaire(PTQ)", which was developed by Thomas and Chess, to assess the temperament of children between the ages of 3 and 7 years through parental questionnaire. METHOD: The samples consisted of 1,175 children who were attending nurseries nationwide. PTQ was translated into Korean language by the authors and distributed to the parents of these children, along with "Toddler Temperament Scale(TTS)" and "Yale Child Inventory(YCI)" which had been previously standardized by different investigators. The reliability and validity of the Korean version of PTQ were tested. RESULTS: Test-retest reliability, item-category correlations and internal consistency of the Korean version of PTQ were generally satisfactory. Correlations between the perceived temperament and the rated temperament were statistically significant in all temperamental categories except distractibility. The correlation between PTQ and TTS was statistically significant in all categories. The 9 categories of PTQ correlated variously with 11 subscales of preschool behavioral assessment of YCI. CONCLUSIONS:The Korean version of PTQ is a standardized tool to assess the temperament of children between ages 3 and 7 years, which will be a useful basic tool for the study of temperament of Korean children.