Changes of Locomotor Activity by Dopamine D2, D3 Agonist Quinpirole in Mice Using Home-cage Monitoring System.

Objective: : As dopamine is closely linked to locomotor activities, animal studies on locomotor activities using dopaminergic agents were widely done. However, most of animal studies were performed for a short period that there is a lack of longitudinal study on the effects of dopaminergic agents on locomotor activities. This study aimed to examine the longterm effect of a dopamine D2, D3 agonist quinpirole on locomotor activities in mice using a home-cage monitoring system. Methods: : The locomotor activities of Institute Cancer Research mice were measured by infrared motion detectors in home-cages under the 12-hour dark and 12-hour light condition for three days after the quinpirole injection. Quinpirole was injected at a concentration of 0.5 mg/kg intraperitoneally in the beginning of the dark phase. The locomotor activities before and after the quinpirole administration were compared by the Wilcoxon signed-rank test and one-way repeated measures ANOVA. Results: : After the quinpirole administration, the 24-hour total locomotor activity did not change (p = 0.169), but activities were significantly increased in the 12-hour dark phase sum (p = 0.013) and decreased in the 12-hour light phase sum (p = 0.009). Significant increases in the activities were observed in the dark-light difference (p = 0.005) and dark-light ratio (p = 0.005) as well. Conclusion: : This study suggests that quinpirole injection entrains the circadian rest-activity rhythm of locomotor activities. Therefore, quinpirole can be a drug that mediates locomotor activity as a dopamine agonist as well as a modulator of the circadian rhythms.

Machine Learning Algorithms for the Prediction of Locomotor Activity by an Infrared Motion Detector on the Sleep-wake States in Mice.

Objective: Even though studies using machine learning on sleep-wake states have been performed, studies in various conditions are still necessary. This study aimed to examine the performance of the prediction model of locomotor activities on sleep-wake states using machine learning algorithms. Methods: The processed data using moving average of locomotor activities were used as predicting features. The sleep-wake states were used as true labels. The prediction models were established by machine learning classifiers such as support vector machine with radial basis function (SVM-RBF), linear discriminant analysis (LDA), naïve Bayes, and random forest (RF). The prediction model was evaluated by a six-fold cross validation. Results: The SVM-RBF and RF showed acceptable performance within a window of moving average from 480 to 1,200 seconds. The highest accuracy (0.869) was shown by the RF at the interval of 480 seconds. Meanwhile, the highest area under the curve (0.939) was shown by LDA at the interval of 870 seconds. Conclusion: This study suggested that the prediction model on sleep-wake state using machine learning could show an improvement of the model performance when using moving average with raw data. The prediction model using locomotor activity can be useful in research on sleep-wake state.

Optimization of Analysis of Circadian Rest-Activity Rhythm Using Cosinor Analysis in Mice.

OBJECTIVE: Data processing in analysis of circadian rhythm was performed in various ways. However, there was a lack of evidence for the optimal analysis of circadian rest-activity rhythm. Therefore, we aimed to perform mathematical simulations of data processing to investigate proper evidence for the optimal analysis of circadian rest-activity rhythm. METHODS: Locomotor activities of 20 ICR male mice were measured by infrared motion detectors. The data of locomotor activities was processed using data summation, data average, and data moving average methods for cosinor analysis. Circadian indices were estimated according to time block, respectively. Also, statistical F and p-values were calculated by zero-amplitude test. RESULTS: The data moving average result showed well-fitted cosine curves independent of data processing time. Meanwhile, the amplitude, MESOR, and acrophase were properly estimated within 800 seconds in data summation and data average methods. CONCLUSION: These findings suggest that data moving average would be an optimal method for data processing in a cosinor analysis and data average within 800-second data processing time might be adaptable. The results of this study can be helpful to analyze circadian restactivity rhythms and integrate the results of the studies using different data processing methods.

Nonfatal injuries in Korean children and adolescents, 2007-2018.

BACKGROUND: Injury is the leading cause of death or disability in children and adolescents. Rates of deaths from injuries have recently declined, but studies of the occurrence of nonfatal injuries are lacking. PURPOSE: This study aimed to investigate nonfatal injuries in children and adolescents younger than 20 years based on data from the Korean National Health and Nutrition Survey, 2007-2018. METHODS: A questionnaire survey was conducted to determine whether children and adolescents had experienced an injury requiring a hospital visit in the previous year. We investigated each injury's risk factors and characteristics. RESULTS: Of a total of 21,598 children and adolescents, 1,748 (weighted percentage, 8.1%) experienced one or more injuries in the previous year. There was no yearly difference in the proportion of injuries experienced. Among the male subjects, 10.0% had an injury experience; among the female participants, 6.1% had an injury experience (P<0.001). The highest rate was 9.0% in children aged 1-4 years. In multivariate logistic regression analysis, male sex; having an urban residence; having restricted activity due to visual, hearing, or developmental impairment; and attention deficit/hyperactivity disorder were significant risk factors for injury experience. The characteristics of up to 3 injuries per patient were investigated, and 1,951 injuries were analyzed. Falls and slips accounted for 34.9%, collisions for 34.1%, and motor vehicle accidents for 11.3% of the total injuries. Ninety-six percent of injuries were unintentional, 20% caused school absences, and 10% required hospitalization. CONCLUSION: Among Korean children and adolescents, 8.1% experienced injuries at least once a year with no significant differences in incidence over the past 12 years. Greater attention and effort to prevent injuries are needed.

Changes in the prevalence of anemia in Korean adolescents, 1998-2018.

BACKGROUND: Anemia is an important health problem affecting approximately 25% of the global population. Although its prevalence is decreasing worldwide, few studies have examined the prevalence of anemia in Korean adolescents. PURPOSE: This study aimed to determine the prevalence of anemia in Korean adolescents over the past 21 years using data from the Korea National Health and Nutrition Examination Survey. METHODS: We investigated the prevalence of anemia in adolescents aged 10-18 years for the period 1998-2018 according to sex, age, residential area, and household income. The effects of menarche age and menstruation were examined in female adolescents for the period 2001-2018. RESULTS: Among the total 11,782 participants, the weighted prevalence of anemia was 4.0%. The prevalence of anemia in male participants significantly decreased (from 3.0% to 0.5%, P<0.001), whereas that in female participants did not change significantly over time (from 7.9% to 8.5%, P=0.054). The average age at menarche was 12.4±0.0 years; the prevalence of anemia in females increased from age 13 years onward. Multivariate analysis revealed that anemia was more common in female than male participants (odds ratio [OR], 9.88; 95% confidence interval [CI], 7.19-13.57; P<0.001). In female adolescents, the prevalence of anemia increased with age (OR, 1.26; 95% CI, 1.15-1.38, P<0.001) and was 3.6 times higher after than before menarche (OR, 3.65; 95% CI, 2.21-6.05, P<0.001). CONCLUSION: Over the 21-year study period, the prevalence of anemia decreased among male adolescents but did not change in female adolescents. In female adolescents, age and menarche were identified as significant risk factors that require continued attention.

Reliability and validity of free software for the analysis of locomotor activity in mice.

Background: Kinovea software that tracking semi-automatically the motion in video screen has been used to study motion-related tasks in several studies. However, the validation of this software in open field test to assess locomotor activity have not been studied yet. Therefore, this study aimed to examine the reliability and validity of this software in analyzing locomotor activities. Methods: Thirty male Institute Cancer Research mice were subjected in this study. The results examined by this software and the classical method were compared. Test-retest reliability and inter-rater reliability were analyzed with Pearson's correlation coefficient and intraclass correlation coefficient (ICC). The validity of this software was analyzed with Pearson's correlation coefficient. Results: This software showed good test-retest reliability (ICC=0.997, 95% confidence interval [CI]=0.975-0.994, p<0.001). This software also showed good inter-rater reliability (ICC=0.987, 95% CI=0.973-0.994, p<0.001). Furthermore, in three analyses for the validity of this software, there were significant correlations between two methods (Pearson's correlation coefficient=0.928-0.972, p<0.001). In addition, this software showed good reliability and validity in the analysis locomotor activity according to time interval. Conclusion: This study showed that this software in analyzing drug-induced locomotor activity has good reliability and validity. This software can be effectively used in animal study using the analysis of locomotor activity.

The Validity of the Bayley-III and DDST-II in Preterm Infants With Neurodevelopmental Impairment: A Pilot Study.

OBJECTIVE: To identify the usefulness of both the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III) and Denver Developmental Screening Test II (DDST-II) in preterm babies with neurodevelopmental impairment, considering the detection rate as regulation of criteria. METHODS: Retrospective medical chart reviews which included the Bayley-III and DDST-II, were conducted for 69 preterm babies. Detection rate of neurodevelopmental impairment in preterm babies were investigated by modulating scaled score of the Bayley-III. The detection rate of DDST-II was identified by regarding more than 1 caution as an abnormality. Then detection rates of each corrected age group were verified using conventional criteria. RESULTS: When applying conventional criteria, 22 infants and 35 infants were detected as preterm babies with neurodevelopmental impairment, as per the Bayley-III and DDST-II evaluation, respectively. Detection rates increased by applying abnormal criteria that specified as less than 11 points in the Bayley-III scaled score. In DDST-II, detection rates rose from 50% to 68.6% using modified criteria. The detection rates were highest when performed after 12 months corrected age, being 100% in DDST II. The detection rate also increased when applying the modified criteria in both the Bayley-III and DDST-II. CONCLUSION: Accurate neurologic examination is more important for detection of preterm babies with neurodevelopmental impairment. We suggest further studies for the accurate modification of the detection criteria in DDST-II and the Bayley-III for preterm babies.

PLASMA CONCENTRATIONS OF VASCULAR ENDOTHELIAL GROWTH FACTOR IN RETINOPATHY OF PREMATURITY AFTER INTRAVITREAL BEVACIZUMAB INJECTION.

PURPOSE: To investigate the changes in plasma concentrations of vascular endothelial growth factor (VEGF), insulin growth factor (IGF-1), erythropoietin, pigment epithelium-derived factor, and IgG1 after bevacizumab intravitreal injection in infants with retinopathy of prematurity. METHODS: Eleven eyes from six infants who received intravitreal injection of bevacizumab were enrolled in this study. At preinjection and postinjection 1, 2, 3, 4, 5, 6, 7, and 8 weeks, 0.5 mL of blood was collected from each infant. The plasma concentrations of VEGF, insulin growth factor, erythropoietin, pigment epithelium-derived factor, and IgG1 were measured by enzyme-linked immunosorbent assay. Five patients received simultaneous bilateral bevacizumab injection; one patient received unilateral injection. RESULTS: Of the infants who received intravitreal bevacizumab injection, two were males and four were females. The mean gestational age was 26 ± 2 weeks. The mean birth weight was 870 g. The mean plasma VEGF concentration before bevacizumab injection was 2.05 ± 3.00 ng/mL; plasma level decreased significantly to 0.16 ± 0.10 ng/mL and to 0.14 ± 0.14 ng/mL (P = 0.028) after 1 week and 2 weeks, respectively. Moreover, the plasma concentrations of VEGF did not return to the original level in any of the samples until 8 weeks after the injection. However, mean plasma IgG1, erythropoietin, insulin growth factor, and PEDF concentrations did not change significantly during the interval between preinjection and any other follow-up time points. CONCLUSION: Intravitreal bevacizumab injections significantly reduce plasma VEGF concentration in infants with retinopathy of prematurity over a 7-week period.

Impact of attachment, temperament and parenting on human development.

The purpose of this review is to present the basic concepts of attachment theory and temperament traits and to discuss the integration of these concepts into parenting practices. Attachment is a basic human need for a close and intimate relationship between infants and their caregivers. Responsive and contingent parenting produces securely attached children who show more curiosity, self-reliance, and independence. Securely attached children also tend to become more resilient and competent adults. In contrast, those who do not experience a secure attachment with their caregivers may have difficulty getting along with others and be unable to develop a sense of confidence or trust in others. Children who are slow to adjust or are shy or irritable are likely to experience conflict with their parents and are likely to receive less parental acceptance or encouragement, which can make the children feel inadequate or unworthy. However, the influence of children's temperament or other attributes may be mitigated if parents adjust their caregiving behaviors to better fit the needs of the particular child. Reflecting on these arguments and our childhood relationships with our own parents can help us develop the skills needed to provide effective guidance and nurturance.