Development of Prediction Model for Suicide Attempts Using the Korean Youth Health Behavior Web-Based Survey in Korean Middle and High School Students / 신경정신의학

Objectives@#Assessing the risks of youth suicide in educational and clinical settings is crucial.Therefore, this study developed a machine learning model to predict suicide attempts using the Korean Youth Risk Behavior Web-based Survey (KYRBWS). @*Methods@#KYRBWS is conducted annually on Korean middle and high school students to assess their health-related behaviors. The KYRBWS data for 2021, which showed 1206 adolescents reporting suicide attempts out of 54848, was split into the training (n=43878) and test (n=10970) datasets. Thirty-nine features were selected from the KYRBWS questionnaire. The balanced accuracy of the model was employed as a metric to select the best model. Independent validations were conducted with the test dataset of 2021 KYRBWS (n=10970) and the external dataset of 2020 KYRBWS (n=54948). The clinical implication of the prediction by the selected model was measured for sensitivity, specificity, true prediction rate (TPR), and false prediction rate (FPR). @*Results@#Balanced bag of histogram gradient boosting model has shown the best performance (balanced accuracy=0.803). This model shows 76.23% sensitivity, 83.08% specificity, 10.03% TPR, and 99.30% FPR for the test dataset as well as 77.25% sensitivity, 84.62% specificity, 9.31% TPR, and 99.45% FPR for the external dataset, respectively. @*Conclusion@#These results suggest that a specific machine learning model can predict suicide attempts among adolescents with high accuracy.

Impulsivity in Major Depressive Disorder Patients with Suicidal Ideation: Event-related Potentials in a GoNogo Task

Objective@#Suicidal ideation is one of the strongest predictors of suicide, and its relevance to impulsivity in depressed patients has been accumulated. Furthermore, high impulsivity patients show the attenuation of the Nogo amplitude in the GoNogo event-related potential (ERP). The purpose of the current study is to determine the correlation of Nogo ERP to the suicidal ideation depending on the condition of its presence or absence in major depressive disorder (MDD) patients. @*Methods@#A total 162 participants (104 patients with suicidal ideation, 31 patients without suicidal ideation, and 27 healthy controls) were recruited, and performed GoNogo tasks during the electroencephalogram measurement. Depression, anxiety, suicidal ideation and impulsivity were assessed by self-rating scales. The clinical measures, behavioral data and Nogo ERP were compared among groups. @*Results@#The MDD with suicidal ideation (SI) group showed significantly decreased Nogo P3 amplitudes compared to MDD without SI (Fz and Cz electrodes) and control group (all electrodes). The MDD with SI group also had significantly low accuracy of both Go and Nogo trails, compared to the MDD without group. The Nogo P3 amplitudes showed the negative relation to the scores of impulsivity, depression, anxiety and SI. @*Conclusion@#Our results concluded that the Nogo P3 ERP amplitude was decreased in MDD patients with SI compared to MDD patients without SI and controls. These findings suggest that the decreased Nogo P3 amplitude is the one of the candidate biomarker for impulsivity in MDD patients to evaluating SI.

Report on the methacholine bronchial provocation test protocol: An updated statement of Korean Academy of Asthma, Allergy and Clinical Immunology

The Korean Academy of Asthma, Allergy, and Clinical Immunology task force report aims to provide new protocols for methacholine challenge test (MCT). Although new devices have different delivery system compared to old ones, previous protocols are still used, which cannot guarantee adequate diagnoses of asthma. Another important issue is the recent recommendation in European Respiratory Society (ERS) technical standard guideline to use a delivered methacholine dose that causes a 20% decrease in forced expiratory volume in 1 second (FEV1) (PD 20). Although the previous protocol based on the methacholine concentration causing a 20% decrease in FEV1 (PC 20) has been used globally, several studies have reported that PD 20 is more reliable and applicable for new protocols of MCT. Indeed, a tidal breathing inhalation protocol using a breath-actuated or continuous nebulizer is recommended. Herein, we recommend 3 protocols for the MCT using new devices and provide a brief summary of the change in strategy based on the updated ERS guideline.

Relationship Between the Loudness Dependence of the Auditory Evoked Potential and the Severity of Suicidal Ideation in Patients with Major Depressive Disorder

Objective@#The loudness dependence of the auditory evoked potential (LDAEP) is a reliable indicator that is inversely related to central serotonergic activity, and recent studies have suggested an association between LDAEP and suicidal ideation. This study investigated differences in LDAEP between patients with major depressive disorder and high suicidality and those with major depressive disorder and low suicidality compared to healthy controls. @*Methods@#This study included 67 participants: 23 patients with major depressive disorder with high suicidality (9 males, mean age 29.3 ± 15.7 years, total score of SSI-BECK ≥ 15), 22 patients with major depressive disorder with low suicidality (9 males, mean age 42.2 ± 14.4 years, total score of SSI-BECK ≤ 14), and 22 healthy controls (11 males, mean age 31.6 ± 8.7 years). Participants completed the following assessments: Patient Health Questionnaire-9, Beck Depression Inventory-II, Beck Scale for Suicidal ideation, State Anxiety Scale of the State-Trait Anxiety Inventory, Beck Anxiety Inventory, and LDAEP (measured at electrode Cz). @*Results@#There were no sex-related differences among groups (p = 0.821). The high-suicidality group exhibited significantly higher LDAEP compared to the low-suicidality group (0.82 ± 0.79 vs. 0.26 ± 0.36, p = 0.014). No significant differences were found between the control and high-suicidality (p = 0.281) or the control and low-suicidality groups (p = 0.236). @*Conclusion@#LDAEP was applied to demonstrate the association between serotonergic activity and suicidal ideation and suicide risk in major depression and may be a candidate of biological marker for preventing suicide in this study.

Relationship Between the Loudness Dependence of the Auditory Evoked Potential and the Severity of Suicidal Ideation in Patients with Major Depressive Disorder

Objective@#The loudness dependence of the auditory evoked potential (LDAEP) is a reliable indicator that is inversely related to central serotonergic activity, and recent studies have suggested an association between LDAEP and suicidal ideation. This study investigated differences in LDAEP between patients with major depressive disorder and high suicidality and those with major depressive disorder and low suicidality compared to healthy controls. @*Methods@#This study included 67 participants: 23 patients with major depressive disorder with high suicidality (9 males, mean age 29.3 ± 15.7 years, total score of SSI-BECK ≥ 15), 22 patients with major depressive disorder with low suicidality (9 males, mean age 42.2 ± 14.4 years, total score of SSI-BECK ≤ 14), and 22 healthy controls (11 males, mean age 31.6 ± 8.7 years). Participants completed the following assessments: Patient Health Questionnaire-9, Beck Depression Inventory-II, Beck Scale for Suicidal ideation, State Anxiety Scale of the State-Trait Anxiety Inventory, Beck Anxiety Inventory, and LDAEP (measured at electrode Cz). @*Results@#There were no sex-related differences among groups (p = 0.821). The high-suicidality group exhibited significantly higher LDAEP compared to the low-suicidality group (0.82 ± 0.79 vs. 0.26 ± 0.36, p = 0.014). No significant differences were found between the control and high-suicidality (p = 0.281) or the control and low-suicidality groups (p = 0.236). @*Conclusion@#LDAEP was applied to demonstrate the association between serotonergic activity and suicidal ideation and suicide risk in major depression and may be a candidate of biological marker for preventing suicide in this study.

Application of Text-Classification Based Machine Learningin Predicting Psychiatric Diagnosis

Objectives@#ZZThe aim was to find effective vectorization and classification models to predict a psychiatric diagnosis from text-basedmedical records. @*Methods@#ZZElectronic medical records (n = 494) of present illness were collected retrospectively in inpatient admission notes withthree diagnoses of major depressive disorder, type 1 bipolar disorder, and schizophrenia. Data were split into 400 training data and 94 independentvalidation data. Data were vectorized by two different models such as term frequency-inverse document frequency (TF-IDF)and Doc2vec. Machine learning models for classification including stochastic gradient descent, logistic regression, support vectorclassification, and deep learning (DL) were applied to predict three psychiatric diagnoses. Five-fold cross-validation was used to find aneffective model. Metrics such as accuracy, precision, recall, and F1-score were measured for comparison between the models. @*Results@#ZZFive-fold cross-validation in training data showed DL model with Doc2vec was the most effective model to predict the diagnosis(accuracy = 0.87, F1-score = 0.87). However, these metrics have been reduced in independent test data set with final workingDL models (accuracy = 0.79, F1-score = 0.79), while the model of logistic regression and support vector machine with Doc2vec showedslightly better performance (accuracy = 0.80, F1-score = 0.80) than the DL models with Doc2vec and others with TF-IDF. @*Conclusions@#ZZThe current results suggest that the vectorization may have more impact on the performance of classification thanthe machine learning model. However, data set had a number of limitations including small sample size, imbalance among the category,and its generalizability. With this regard, the need for research with multi-sites and large samples is suggested to improve the machinelearning models.

Application of Text-Classification Based Machine Learningin Predicting Psychiatric Diagnosis

Objectives@#ZZThe aim was to find effective vectorization and classification models to predict a psychiatric diagnosis from text-basedmedical records. @*Methods@#ZZElectronic medical records (n = 494) of present illness were collected retrospectively in inpatient admission notes withthree diagnoses of major depressive disorder, type 1 bipolar disorder, and schizophrenia. Data were split into 400 training data and 94 independentvalidation data. Data were vectorized by two different models such as term frequency-inverse document frequency (TF-IDF)and Doc2vec. Machine learning models for classification including stochastic gradient descent, logistic regression, support vectorclassification, and deep learning (DL) were applied to predict three psychiatric diagnoses. Five-fold cross-validation was used to find aneffective model. Metrics such as accuracy, precision, recall, and F1-score were measured for comparison between the models. @*Results@#ZZFive-fold cross-validation in training data showed DL model with Doc2vec was the most effective model to predict the diagnosis(accuracy = 0.87, F1-score = 0.87). However, these metrics have been reduced in independent test data set with final workingDL models (accuracy = 0.79, F1-score = 0.79), while the model of logistic regression and support vector machine with Doc2vec showedslightly better performance (accuracy = 0.80, F1-score = 0.80) than the DL models with Doc2vec and others with TF-IDF. @*Conclusions@#ZZThe current results suggest that the vectorization may have more impact on the performance of classification thanthe machine learning model. However, data set had a number of limitations including small sample size, imbalance among the category,and its generalizability. With this regard, the need for research with multi-sites and large samples is suggested to improve the machinelearning models.

Age-Related Changes in Auditory Nogo-N200 Latency in Medication-Naïve Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

Objective@#Event-related potential (ERP) changes with brain development in healthy children and adolescents. However, few studies have focused on age-related changes in the N200 and P300 components among individuals with attention-deficit/hyperactivity disorder (ADHD). Therefore, this study aimed to assess age-related differences in the auditory nogo-N200 components in individuals with ADHD. @*Methods@#We enrolled 46 participants with auditory nogo-N200 and nogo-P300 components. We assessed ADHD symptoms using the Advanced Test of Attention (ATA) and Korean ADHD Rating Scale-IV (K-ARS-IV). Moreover, we assessed emotional and behavioral problems using the Korean Child Behavior Checklist (K-CBCL). Further, we measured auditory ERPs. @*Results@#There were no differences with respect to sex or ATA, K-ARS-IV, and K-CBCL scores between the groups. With a 1-year increase in age, the nogo-N200 latency at Fz and Cz decreased by 6.08 ms and 4.88 ms, respectively; this result was statistically significant in multivariable linear regression adjusted by sex and dominant hand. @*Conclusion@#Our findings revealed age-related changes in nogo-N200 latency at the Fz and Cz electrodes in individuals with ADHD. Future studies should perform comparisons with healthy controls to determine whether auditory nogo-N200 can be used to evaluate the developmental level in individuals with ADHD.

Clinical characteristics and cholinesterase levels in childrenwith carbofuran poisoning

Objective@#Acute group poisoning caused by food ingestion occurred in an elementary school in Korea. We aimed todescribe the clinical characteristics, emergency treatment, outcomes, and the cholinesterase level of children with carbofuranpoisoning. @*Methods@#We recruited 32 children who were transferred to hospitals, and they underwent physical examination and laboratoryinvestigations with detailed history-taking performed at one week after carbofuran poisoning. A questionnaireabout presenting symptoms, the transport process, treatment, and the clinical course was conducted with their parent’sagreement. We compared the level of cholinesterase in red blood cells (RBCs) of the child patients without poisoning. @*Results@#The most common presenting symptoms were hypersalivation (84.4%), dizziness (68.8%), nausea (65.6%),and tremor of the limbs (56.3%). Among them, nine children were transported from the initial hospital to a higher levelemergency medical center. Both cholinesterase measurements and atropine injection were done only at a provincialemergency medical center. One child who required ventilator care and was admitted to the intensive care unit showed alow serum cholinesterase level until one week. Six children had symptoms that lasted until a week. Patients showed asignificantly lower RBC cholinesterase level than did the children without poisoning (11974 [95% CI 10257-13997] vs13025 [95% CI 12157-13552] IU/gHb) (P=0.017). @*Conclusion@#The clinical features and cholinesterase activity of children with carbamate poisoning may be different fromthose of adults with carbamate poisoning. RBC acetylcholinestrase was significantly lower than that of healthy childrenuntil a week after carbofuran poisoning. Cholinersterase could be decreased for a long time, against our expectations,and it is a biomarker of exposure to carbofuran in children by serial monitoring.

Associated Factors for Asthma Severity in Korean Children: A Korean Childhood Asthma Study

PURPOSE: Childhood asthma has a considerable social impact and economic burden, especially in severe asthma. This study aimed to identify the proportion of childhood asthma severity and to evaluate associated factors for greater asthma severity. METHODS: This study was performed on 667 children aged 5–15 years with asthma from the nationwide 19 hospitals in the Korean childhood Asthma Study (KAS). Asthma was classified as mild intermittent, mild persistent, and moderate/severe persistent groups according to the National Asthma Education and Prevention Program recommendations. Multinomial logistic regression models were used to identify the associated factors for greater asthma severity. RESULTS: Mild persistent asthma was most prevalent (39.0%), followed by mild intermittent (37.6%), moderate persistent (22.8%), and severe persistent asthma (0.6%). Onset later than 6 years of age (adjusted odds ratio [aOR], 1.69 for mild persistent asthma; aOR, 1.92 for moderate/severe persistent asthma) tended to increase asthma severity. Exposure to environmental tobacco smoke (aOR, 1.53 for mild persistent asthma; aOR, 1.85 for moderate/severe persistent asthma), and current dog ownership with sensitization to dog dander (aOR, 5.86 for mild persistent asthma; aOR, 6.90 for moderate/severe persistent asthma) showed increasing trends with greater asthma severity. Lower maternal education levels (aOR, 2.32) and no usage of an air purifier in exposure to high levels of outdoor air pollution (aOR, 1.76) were associated with moderate/severe persistent asthma. CONCLUSIONS: Modification of identified environmental factors associated with greater asthma severity might help better control childhood asthma, thereby reducing the disease burden due to childhood asthma.

Risk Factors and Comorbidities Associated With the Allergic Rhinitis Phenotype in Children According to the ARIA Classification

PURPOSE: Data are lacking on the association between the allergic rhinitis (AR) phenotype and sensitization to specific allergens or bronchial hyperresponsiveness (BHR) in children. We here investigated risk factors and comorbidities, including sensitization to specific allergens and BHR, for the AR phenotype by AR and its Impact on Asthma (ARIA) classification in a general population-based birth cohort study. METHODS: We enrolled 606 children aged 7 years from the Panel Study of Korean Children. The AR phenotype was assigned in accordance with the ARIA classification in children. Skin prick tests and Provocholine provocation test were performed. Risk factors and comorbidities for AR phenotypes were then analyzed. RESULTS: The prevalence of mild and moderate to severe AR in our study cohort was 37.2% and 8.8%, respectively. Recent use of analgesics or antipyretics and current cat ownership were associated with the risk of mild persistent AR. Sensitizations to Dermatophagoides Pteronyssinus (Der p), Japanese hop and cat were associated with moderate to severe persistent AR. Children with moderate to severe AR had a higher risk of current asthma and BHR compared to mild AR cases (adjusted odds ratio [aOR], 5.26; 95% confidence interval [CI], 1.77–15.62). Moderate to severe AR with allergic sensitization was associated with the highest risk of BHR (aOR, 11.77; 95% CI, 3.40–40.74). CONCLUSIONS: Moderate to severe-persistent AR is more closely related to respiratory comorbidities and sensitizations than mild AR. Stratifying the AR phenotype by ARIA classification may assist in disease management.

Fractional exhaled nitric oxide and forced expiratory volume in 1 second/forced vital capacity have predictive value of asthma exacerbation in Korean school children

BACKGROUND: The incidence of asthma exacerbation (AE) and the predictive value of spirometry and fractional exhaled nitric oxide (FeNO) in school children have not been evaluated.OBJECTIVE: We sought to evaluate the efficacy of spirometry measurement and FeNO monitoring for predicting AE in school children in the Cheongju area in Korea.METHODS: With parental agreement, we studied 170 students aged 7–12 years. Children were evaluated by an asthma specialist using baseline spirometry, skin prick test, seasonal FeNO measurement, and asthma control test. The study participants underwent a physical examination and their medical history was also evaluated by the specialist. They were assessed for asthma control status during regular doctor visits for 1 year.RESULTS: In total, 160 children (94.1%) completed follow-up and FeNO monitoring. Of which, 26 children (16.3%) had AE. AE was associated with male children and children with allergic rhinitis (p < 0.05). While, children with AE tended to have higher FeNO than those without AE, no significant difference was found. The maximum value of FeNO ≥35 ppb was associated with AE (p < 0.05). Children with AE had a significantly decreased baseline forced expiratory volume in 1 second/forced vital capacity (FEV₁/FVC), %predicted, forced expiratory flow at 25%–75% of FVC (FEF(25%–75%)). FEV₁/FVC < 80% was associated with AE in children regardless of inhalant allergen sensitization (all p < 0.05).CONCLUSION: Baseline spirometry had a predictive value of AE in school children. Sensitive spirometric parameters such as FEV₁/FVC and FEF(25%–75%) can be used as prognostic factors to predict future childhood AE. FeNO value ≥ 35 ppb during monitoring was associated with AE in school children.

Indoor pet ownership in infancy is a risk factor for the development of sensitization to pets and asthma in childhood

PURPOSE: It is controversial whether indoor pet exposure is either a risk or protective factor developing sensitization to pet allergens or asthma. Therefore, we investigated whether indoor pet ownership entails a risk for the development of asthma and sensitization in childhood. METHODS: The Panel Study of Korean Children (PSKC) is a general-population-based birth cohort study that recruited 2,078 mother-baby dyads in Korea between April and July of 2008. Among 1,577 children who were followed up in 2015, 559 underwent skin prick tests, spirometry and bronchial provocation tests using Provocholine. Having a cat or a dog and the prevalence of asthma were evaluated by using self-reported questionnaires and physicians’ medical records. RESULTS: During infancy, the rate of dog ownership was 4.5% (71 of 1,574) and that of cat ownership was 0.5% (8 of 1,574). Of the subjects, 7.9% (n=109) currently had at least 1 dog and 2.5% (n=34) had at least 1 cat. Pet ownership during infancy was associated with sensitization to cats or dogs (adjusted odds ratio [aOR], 4.24; 95% confidence interval [CI], 1.29–13.98), wheezing within 12 months (aOR, 5.56; 95% CI, 1.65–18.75) and current asthma (wheezing episode in the last 12 months+diagnosed asthma by physicians) (aOR, 6.36; 95% CI, 1.54–26.28). In contrast, pet ownership during the last 12 months was not associated with sensitization to cats or dogs or current asthma. CONCLUSION: Indoor pet exposure during infancy can be critical for developing sensitization to cats or dogs and asthma in childhood. Avoidance of pet exposure in early life may reduce sensitization to cats or dogs and development of asthma.

Association Analysis between Chromogranin B Genetic Variations and Smooth Pursuit Eye Movement Abnormality in Korean Patients with Schizophrenia

OBJECTIVES: According to previous studies, the Chromogranin B (CHGB) gene could be an important candidate gene for schizophrenia which is located on chromosome 20p12.3. Some studies have linked the polymorphism in CHGB gene with the risk of schizophrenia. Meanwhile, smooth pursuit eye movement (SPEM) abnormality has been regarded as one of the most consistent endophenotype of schizophrenia. In this study, we investigated the association between the polymorphisms in CHGB gene and SPEM abnormality in Korean patients with schizophrenia. METHODS: We measured SPEM function in 24 Korean patients with schizophrenia (16 male, 8 female) and they were divided according to SPEM function into two groups, good and poor SPEM function groups. We also investigated genotypes of polymorphisms in CHGB gene in each group. A logistic regression analysis was performed to find the association between SPEM abnormality and the number of polymorphism. RESULTS: The natural logarithm value of signal/noise ratio (Ln S/N ratio) of good SPEM function group was 4.19 ± 0.19 and that of poor SPEM function group was 3.17 ± 0.65. In total, 15 single nucleotide polymorphisms of CHGB were identified and the genotypes were divided into C/C, C/R, and R/R. Statistical analysis revealed that two genetic variants (rs16991480, rs76791154) were associated with SPEM abnormality in schizophrenia (p = 0.004). CONCLUSIONS: Despite the limitations including a small number of samples and lack of functional study, our results suggest that genetic variants of CHGB may be associated with SPEM abnormality and provide useful preliminary information for further study.

Relation of allergic rhinitis, allergen sensitization, and air pollutants in preschool children

PURPOSE: We aimed to investigate the prevalence and allergen sensitization of allergic rhinitis (AR) in preschool children. We assessed the relationship of AR, allergen sensitization, and air pollutants. METHODS: Between 2012 and 2016 in Jincheon, skin prick testing and questionnaire survey were performed on 2,958 children. AR have diagnosed on the basis of current symptoms and sign of AR on the Korean International Study of Asthma and Allergies in Childhood questionnaire and 1 or more proven allergen sensitization. RESULTS: A total of 2,052 children completed survey and skin prick testing, and were included in the analysis. The prevalence of AR symptom within last 12 months and AR were 27.0% and 10.9%, respectively. During study, both prevalences were increased from 20.1% and 8.6%, respectively in 2012 to 29.1% and 12.8%, respectively in 2016. The total inhalant allergen sensitization rate was 32.6%. The most common inhalant allergen was Dermatophagoides farinae (23.1%), followed by Dermatophagoides pteronyssinus (22.5%), tree pollens (5.3%), weed pollens (5.2%), fungi (4.7%), dog hair (4.5%) cat fur (3.6%), grass pollens (1.1%), and cockroach (0.8%). Although there was no difference tree or weed pollen sensitization, pollen seasonal prevalence of current AR symptoms is highest in spring (80%) versus autumn (52.3%). Seasonal PM10 (particulate matter with a median aerodynamic diameter less than or equal to 10 µm in diameter) and SO2 (sulfur dioxide) levels were correlated with the prevalence of seasonal AR symptoms. Pollen seasonal current AR symptoms were significantly related to seasonal pollen sensitization, but not inhalant allergens including dust mites. CONCLUSION: There was a rapid increasing prevalence of AR in preschool children in the areas of urbanization and industrialization. Pollen seasonal current AR symptoms have a close relationship with PM10 and seasonal pollen sensitization.

Prevalence, Risk Factors and Cutoff Values for Bronchial Hyperresponsiveness to Provocholine in 7-Year-Old Children

BACKGROUND: A US Food and Drug Administration (FDA)-approved drug methacholine chloride (Provocholine®) was recently introduced to Korea where it is now widely used in clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine in 7-year-old children. METHODS: Six hundred and thirty-three children from the Panel Study on Korean Children who visited 16 regional hospitals were evaluated. Skin prick tests, spirometry and bronchial provocation tests for Provocholine as well as a detailed history and physical examinations were performed. The bronchial provocation test was reliably performed on 559 of these children. RESULTS: The prevalence of ever-diagnosed asthma via medical records was 7.7%, and that of current asthma (wheezy episode in the last 12 months + diagnosed asthma by physicians) was 3.2%. The prevalence of BHR to Provocholine was 17.2% and 25.8%, respectively, for a PC20 < 8 and < 16 mg/mL. The risk factors for BHR (PC20 < 16 mg/mL) were atopic dermatitis diagnosis and current dog ownership, whereas those for current asthma were allergy rhinitis diagnosis, a history of bronchiolitis before the age of 3, recent use of analgesics/antipyretics and maternal history of asthma. The BHR prevalence trend showed an increase along with the increased immunoglobulin E (IgE) quartile. The cutoff value of PC20 for the diagnosis of current asthma in children at age 7 was 5.8 mg/mL (sensitivity: 47.1%, specificity: 87.4%). CONCLUSIONS: BHR to Provocholine (PC20 < 8 mg/mL) was observed in 17.2% of 7-year-olds children from the general population and the cutoff value of PC20 for the diagnosis of current asthma was 5.8 mg/mL in this age group. The risk factors for BHR and current asthma showed discrepancies suggesting different underlying mechanisms. Bronchial provocation testing with Provocholine will be a useful clinical tool in the future.

Gender-Specific Associations between CHGB Genetic Variants and Schizophrenia in a Korean Population

PURPOSE: Schizophrenia is a devastating mental disorder and is known to be affected by genetic factors. The chromogranin B (CHGB), a member of the chromogranin gene family, has been proposed as a candidate gene associated with the risk of schizophrenia. The secretory pathway for peptide hormones and neuropeptides in the brain is regulated by chromogranin proteins. The aim of this study was to investigate the potential associations between genetic variants of CHGB and schizophrenia susceptibility. MATERIALS AND METHODS: In the current study, 15 single nucleotide polymorphisms of CHGB were genotyped in 310 schizophrenia patients and 604 healthy controls. RESULTS: Statistical analysis revealed that two genetic variants (non-synonymous rs910122; rs2821 in 3′-untranslated region) were associated with schizophrenia [minimum p=0.002; odds ratio (OR)=0.72], even after correction for multiple testing (p(corr)=0.02). Since schizophrenia is known to be differentially expressed between sexes, additional analysis for sex was performed. As a result, these two genetic variants (rs910122 and rs2821) and a haplotype (ht3) showed significant associations with schizophrenia in male subjects (p(corr)=0.02; OR=0.64), whereas the significance disappeared in female subjects (p>0.05). CONCLUSION: Although this study has limitations including a small number of samples and lack of functional study, our results suggest that genetic variants of CHGB may have sex-specific effects on the risk of schizophrenia and provide useful preliminary information for further study.

No Association between (AAT)n Repeat Polymorphisms in the Cannabinoid Receptor 1 Gene and Smooth Pursuit Eye Movement Abnormality in Korean Patients with Schizophrenia

OBJECTIVES: According to previous studies, the cannabinoid receptor 1 (CNR1) gene could be an important candidate gene for schizophrenia. Some studies have linked the (AAT)n trinucleotide repeat polymorphism in CNR1 gene with the risk of schizophrenia. Meanwhile, smooth pursuit eye movement (SPEM) has been regarded as one of the most consistent endophenotypes of schizophrenia. In this study, we investigated the association between the (AAT)n trinucleotide repeats in CNR1 gene and SPEM abnormality in Korean patients with schizophrenia. METHODS: We measured SPEM function in 167 Korean patients with schizophrenia (84 male, 83 female) and they were divided according to SPEM function into two groups, good and poor SPEM function groups. We also investigated allele frequencies of (AAT)n repeat polymorphisms on CNR1 gene in each group. A logistic regression analysis was performed to find the association between SPEM abnormality and the number of (AAT)n trinucleotide repeats. RESULTS: The natural logarithm value of signal/noise ratio (Ln S/N ratio) of the good SPEM function group was 4.34 ± 0.29 and that of the poor SPEM function group was 3.21 ± 0.70. In total, 7 types of trinucleotide repeats were identified, each containing 7, 10, 11, 12, 13, 14, and 15 repeats, respectively. In the patients with (AAT)₇ allele, the distributions of the good and poor SPEM function groups were 18 (11.1%) and 19 (11.0%) respectively. In the patients with (AAT)₁₀ allele, (AAT)₁₁ allele, (AAT)₁₂ allele, (AAT)₁₃ allele, (AAT)₁₄ allele and (AAT)₁₅ allele, the distributions of good and poor SPEM function groups were 13 (8.0%) and 12 (7.0%), 4 (2.5%) and 6 (3.5%), 31 (19.8%) and 35 (20.3%), 51 (31.5%) and 51 (29.7%), 36 (22.2%) and 45 (26.2%), 9 (5.6%) and 4 (2.3%) respectively. As the number of (AAT) n repeat increased, there was no aggravation of abnormality of SPEM function. CONCLUSIONS: There was no significant aggravation of SPEM abnormality along with the increase of number of (AAT)n trinucleotide repeats in the CNR1 gene in Korean patients with schizophrenia.

Translation and linguistic validation of Korean version of the Test for Respiratory and Asthma Control in Kids instrument

PURPOSE: We aimed to translate the Test for Respiratory and Asthma Control in Kids (TRACK) instrument into Korean, with subsequent linguistic validation. METHODS: The multistep process of forward translation, reconciliation, back-translation, cognitive debriefing, and proofreading of the Korean version of the TRACK was completed. RESULTS: Two bilingual medical personnel independently translated the original English version of the TRACK into Korean one. After moderating the translation into a single reconciled one, 4 other bilingual persons were invited to translate the Korean draft back into an English one. Discrepancies between the original English version and the back-translated one were reviewed, and the need to modify the reconciled Korean draft was discussed. Twenty caregivers of asthmatic children took part in interviews that examine the appropriateness of the Korean version of the TRACK. The feedback from caregivers were then reviewed by a panel of pediatric allergists and reflected in the final Korean version. The document was finally proofread to check the spelling, grammar, layout and formatting. CONCLUSION: Translation and linguistic validation of the Korean version of the TRACK instrument were completed.

Prasugrel-Induced Hypersensitivity Skin Reaction

We report a case of hypersensitivity skin reaction to prasugrel. The patient exhibited a generalized skin rash after treatment with prasugrel, which was resolved after discontinuation of prasugrel and substitution to clopidogrel. Clopidogrel was successfully administered as an alternative to prasugrel without any signs of further hypersensitivity.