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.

Influences of Dopamine D2, D3 Agonist Quinpirole Dosage on Locomotor Activity Measured by Open-FieldTest / 우울ㆍ조울병

Background@#Dopamine D2 and D3 receptor agonist quinpirole have been tried as one of drug-induced bipolar animal models. An open-field test is used to assess locomotor activity related to anxiety. Not many studies have analyzed the effects of quinpirole dosages on locomotor activity. The purpose of this study was to look at the locomotor activity of quinpirole-injected mice in an open-field test. @*Methods@#The open-field test was used to observe the locomotor activities of 28 mice. Quinpirole was administrated at 0.05-5 mg/kg and normal saline were used as a control. The Mann-Whitney U-test was employed to compare the locomotor activities in the quinpirole and control groups. @*Results@#Quinpirole-induced locomotor activities reduced as time elapsed during the first 30 minutes following the injection in most mice, then increased or fluctuated in the later 30 minutes. As the dosage was increased, there was a stronger initial inhibition, followed by a rapid and further increase in the last 30 minutes. @*Conclusion@#This study showed the differential effects of quinpirole-induced locomotor activities depending on dosage, and initial suppression of locomotor activities by quinpirole was observed. Additionally, longitudinal observation of more than 1 hour would be required to look into the biphasic pattern of quinpirole in an animal model.

Analysis of ultradian rest-activity rhythms using locomotor activity in mice / 고신대학교의과대학학술지

Background@#Locomotor activity in mice may have an ultradian rest-activity rhythm. However, to date, no study has shown how locomotor activity can be explained statistically using fitted cosine curves. Therefore, this study explored whether the ultradian rhythm of locomotor activity in mice could be analyzed using cosine fitting analysis. @*Methods@#The locomotor activity of 20 male mice under a 12/12-hour dark/light cycle for 2 days was fitted to a cosine function to obtain the best fit. The mean absolute error (MAE) values were used to determine the explanatory power of the calculated cosine model for locomotor activity. The cosine fitting analysis was performed using R statistical software (version 4.1.1). @*Results@#The mean MAE was 0.2944, whereas the mean MAE for integrating the individual analyses in the two experimental groups was 0.3284. The periods of the estimated ultradian rest-activity rhythm ranged from 1.602 to 4.168 hours. @*Conclusions@#These results suggest that locomotor activity data reflect an ultradian rhythm better than a circadian rhythm. Locomotor activity can be statistically fitted to a cosine curve under well-controlled conditions. In the future, it will be necessary to explore whether this cosine-fitting analysis can be used to analyze ultradian rhythms under different experimental conditions.

Performance comparison between Elecsys Anti-SARS-CoV-2 and Anti-SARS-CoV-2 S and Atellica IM SARS-CoV-2 Total and SARS-CoV-2 IgG assays / 고신대학교의과대학학술지

Background@#Although serological severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) tests from several manufacturers have been introduced in South Korea and some are commercially available, the performance of these test kits has not yet been sufficiently validated. Therefore, we compared the performance of Elecsys Anti-SARS-CoV-2 (ACOV2) and Anti-SARS-CoV-2 S (ACOV2S) and Atellica IM SARS-CoV-2 Total (COV2T) and SARS-CoV-2 IgG (sCOVG) serological tests in this study. @*Methods@#A total of 186 patient samples were used. For each test, we analyzed the positive rate of serological antibody tests, precision, linearity, and agreement among the four assays. @*Results@#The positive rates of COV2T, sCOVG, and ACOV2S were high (81.7%–89.2%) in total, with those for ACOV2S being the highest, while those of ACOV2 were as low as 44.6%. This may be related to the high completion rate of vaccination in Korea. The repeatability and within-laboratory coefficients of variation were within the claimed allowable imprecision; however, further research is needed to establish an allowable imprecision at low concentrations. COV2T showed a linear fit, whereas sCOVG and ACOV2S were appropriately modeled with a nonlinear fit. Good agreement was found among COV2T, sCOVG, and ACOV2S; however, the agreement between ACOV2 and any one of the other methods was poor. @*Conclusions@#Considering the different antigens used in serological SARS-CoV-2 antibody assays, the performance of the tested assays is thought to show no significant difference for the qualitative detection of antibodies to SARS-CoV-2.

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.

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

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.

Comparison of Hemoglobin Correction Effects According to Storage Period and Other Factors in the Transfusion of Packed Red Blood Cells in Neonatal Intensive Care Unit Patients

PURPOSE: Preterm infants frequently require red blood cell (RBC) transfusions in neonatal intensive care units (NICU). Storage RBCs undergo many changes during storage periods. We aimed to compare the hemoglobin (Hb) correction effect according to the period of RBC storage and investigate the factors influencing Hb correction. METHODS: This retrospective study reviewed the medical records of 289 patients who received RBC transfusion more than once in the NICU of Kosin University Gospel Hospital between February 2006 and March 2016. The subjects were classified into two storage groups: short-term (≤7 days, n=88) and long-term (>7 days, n=201), according to the period of RBC storage. We checked Hb levels by complete blood cell count tests conducted within 2 days before and 5 to 9 days after the first transfusion. We compared the Hb difference between the two groups and analyzed the factors influencing Hb correction. RESULTS: Excluding the use of an invasive ventilator, there was no significant difference between the two groups in terms of clinical characteristics. There was no significant difference in the Hb correction effect between the two groups (P=0.537). Birth weight greater than 1,500 g, higher weight at transfusion, and larger volume of transfusion were significant prognostic factors affecting greater changes in Hb. In addition, surgery experience, higher Hb level at transfusion, and additional blood tests were found to be significantly associated with less changes in Hb. CONCLUSION: The RBC storage period did not affect the Hb correction effect. The Hb correction effect may be diminished in infants with lower birth weight and lower weight at transfusion under unstable clinical conditions.

A Case of Transient Myeloproliferative Disorder Associated with Clonal Trisomy 21 in a Chromosomally Normal Newborn / 임상소아혈액종양

Transient myeloproliferative disorder (TMD) is similar to congenital leukemia, with leukocytosis, increased peripheral blast cells, and hepatomegaly in the neonatal period. Although TMD occurs only in patients with Down syndrome and trisomy 21 mosaicism, there have been reports of congenital leukemia with trisomy 21 limited to hematopoietic cells showing spontaneous resolution. We identified trisomy 21 in the leukemic cells in a patient with congenital leukemia. As there was no other gene abnormality, we stopped chemotherapy, and the disease resolved spontaneously. We reviewed the cases of clonal trisomy 21 TMD and found that their clinical features were similar to those of TDM associated with Down syndrome. In conclusion, in a phenotypically normal patient with suspected congenital leukemia, it is necessary to confirm the presence of 21 trisomy. If the neonate has only trisomy 21 without other gene abnormalities, intensive chemotherapy may not be required.

A Multicenter Survey on the Current Status of Pediatric Blood Cultures in Korea

PURPOSE: Blood culture is an essential diagnostic tool and requires clear indications, proper techniques, and quality control. We aimed to investigate whether blood cultures in children are appropriate for indications, are performed correctly, and receive proper quality control. METHODS: We conducted an online survey targeting pediatric infectious diseases (ID) specialists working in general hospitals and neonatologists (Neo) working at hospitals operating a neonatal intensive care unit in Korea. RESULTS: Approximately 81.1% (30/37) of pediatric ID specialists and 72.2% (52/72) of Neo responded to the survey. Some of the respondents (33.3% of ID and 59.6% of Neo) performed blood culture as a regular test irrespective of the indication. Approximately 40% of ID and 65.4% of Neo ordered only one set of blood culture in patients suspected with bacteremia. The most commonly used disinfectant for skin preparation was povidone-iodine, while the skin preparation method varied by institution. Approximately two-thirds of the institutions were monitoring the blood culture contamination rate, whereas relatively few provided staff with feedback on that rate. In addition, less than half of the institutions were providing regular staff training on blood culture (40% of ID and 28.8% of Neo). CONCLUSIONS: The indication and methods of blood culture for children varied according to institution, and few hospitals exert effort in improving the quality of blood culture. Institutions have to strive constantly toward improvement of blood culture quality and evidence-based recommendations for pediatric blood cultures should be standardized.

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

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.

Influenza A Outbreak in a Neonatal Intensive Care Unit During the 2011-2012 Influenza Season in Korea

PURPOSE: An outbreak of influenza virus is uncommon in neonatal intensive care unit (NICU). The clinical presentation of influenza virus infection in neonates is diverse. This study was aimed to report an outbreak of influenza A in a NICU and to investigate the clinical characteristics of influenza virus infection in neonates especially preterm infants during the 2011-2012 influenza season in Korea. METHODS: We reviewed the medical records of 29 patients who were evaluated by respiratory virus multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) at NICU of Kosin University Gospel Hospital during the 2011-2012 seasonal influenza outbreak in Korea. RESULTS: Eleven patients (37.9%) were influenza A virus RT-PCR positive during the survey periods. They were all preterm infants and three of them had no symptoms. Eight patients had symptoms and it was fever (18%, 2/11), respiratory difficulty (72.7%, 8/11) without symptoms of upper respiratory infection, and gastrointestinal symptoms (27.3%, 3/11). The median duration of symptom was 5 days. There were differences of duration of admission at the test of respiratory RT-PCR, Clinical Risk Index for Babies (CRIB) score, use of mechanical ventilation, and use of dexamethasone before infection between influenza A virus RT-PCR positive and negative group. All 11 patients with influenza A were discharged without any complications. CONCLUSIONS: The symptoms of influenza A virus infection in the preterm infants is nonspecific. Influenza A virus should be considered as a possible cause of infection in NICU during the influenza season in the community.

Clinical Characteristics Associated with Blood Culture Contamination in Neonates

PURPOSE: This study was aimed to investigate the contamination rates of blood culture in a neonatal intensive care unit (NICU) and to examine the clinical characteristics related to the contamination. METHODS: Eight hundred thirty cases of blood culture performed from March 2013 to February 2014 were analyzed. We evaluated the contamination rates of blood culture by blood sampling sites and compared the clinical characteristics such as real name system and body weights of the contaminated cases and those of non-contaminated ones. The clinical characteristics were retrospectively reviewed by medical records. RESULTS: The overall contamination rate was 3.6% (30/830). The contamination rates by blood sampling sites were as follows: peripheral vein 15.6% (10/64), peripheral artery 2.6% (20/759), and umbilical arterial catheter 0% (0/7). There was no difference in the contamination rates between cases with and without real name system (P =0.484). However, there were significant differences in the contamination rates by the physicians who performed the culture (P =0.038) and body weight ( or =1,000 g) at the time of blood culture (P<0.001). CONCLUSIONS: These results suggest that neonates with a body weight less than 1,000 g have more risks of the contamination of blood culture. Furthermore, there is a necessity to provide blood culture performers with active feedbacks and individualized education plans that can help diminish blood culture contamination rates. Prospective studies in a systematic manner that can be applied in actual clinical settings are needed in order to figure out factors that can diminish the contamination rates of blood culture in NICU.

Preterm Ovarian Hyperstimulation Syndrome

Preterm ovarian hyperstimulation syndrome (POHS) is characterized by swelling of the vulva and hypogastrium, elevated estradiol and gonadotropin levels, and multiple ovarian follicular cysts in premature baby girls. We report a case of POHS with a review of the literature. The patient presented with swelling of the clitoral hood, and the labia majora and minora. We confirmed multiple ovarian cysts, as well as elevated estradiol and lutenizing hormone levels by performing pelvic ultrasound and laboratory tests. The symptoms resolved gradually and spontaneously.

Clinical Features and Factors Associated with the Frequency of Phototherapy in Premature Birth Gestation < 35 Weeks and Birth Weight < or =2,500 g / 고신대학교의과대학학술지

OBJECTIVES: Clinical features according to the frequency of phototherapy and clinical risk factors on the number of phototherapy were investigated in premature births with gestation <35 weeks and birth weight < or =2,500 g. METHODS: The 186 infants with gestation <35 weeks and birth weight < or =2,500 g were admitted to the neonatal intensive care unit of Kosin University Gospel Hospital from March 2009 to August 2010. The 171 infants were alive and had jaundice requiring phototherapy. Phototherapy was usually started to 50-70% of the maximal bilirubin level. They were divided into two groups according to the frequency of phototherapy as single phototherapy group (group I) and multiple phototherapy group (group II). We retrospectively reviewed the medical records of all patients. RESULTS: The mean gestational age and birth weight of group I were 31.0+/-2.9 weeks and 1,596+/-485 g and those of group II were 31.1+/-2.6 weeks and 1,592+/-430 g. Compared with group I, albumin and Apgar score at 1 minute of group II were significantly higher and the day of peak bilirubin was also late. Duration of phototherapy in group II was statistically longer than that group I but duration of ventilator and aminophylline use for apnea was significantly shorter. The frequency of antibiotic use, incidence of bronchopulmonary dysplasia (BPD), and intraventricular hemorrhage (IVH) of group II were significantly lower than those of group I. CONCLUSIONS: The day of peak bilirubin was late and the frequency of antibiotic use, incidence of BPD, and IVH were low in group II. The aggressive phototherapy may be considered in premature births with jaundice.

Bronchial Perforation Complicating Endotracheal Intubation in an Extremely Low Birth Weight Infant

Bronchial injury is a rare and serious complication of endotracheal intubation in neonates. Bronchial perforation following tracheal intubation causes a high-volume air leak mimicking pneumothorax and pneumomediastinum, and it may result in intraventricular hemorrhage, mediastinitis and sepsis. I report my experience of diagnosing a main bronchial perforation in an extremely low birth weight infant, who had a high-volume air leak following tracheal intubation, which persisted after chest tube insertion.

Central Diabetes Insipidus Associated with Symptomatic Cytomegalovirus Infection in an Extremely Low Birth Weight Infant

I report a case of extremely low birth weight infant, who presented central diabetes insipidus associated with cytomegalovirus infection. His brain magnetic resonance imaging showed a flattened pituitary gland, and demonstrated a lack of posterior pituitary hyperintensity. It successfully managed with oral desmopressin (Minirin(R)) and persisted beyond the resolving of symptomatic cytomegalovirus infection.

Impact of attachment, temperament and parenting on human development / 소아과

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.

Assessment of Iron Parameters in Children with Acute Infectious Disease / 임상소아혈액종양

BACKGROUND: As some parameters reflecting iron status were known to change with infection or inflammation, we examined the changes of these parameters in children with minor illnesses.METHODS: Hematologic tests were done in 42 young children with acute infection. Iron deficiency anemia (IDA) was defined as having Hb less than age-matched normal range, MCH <27 pg, and either Tfsat (transferrin saturation) <10% or TIBC >360 microg/dL. Iron deficiency (ID) was defined as having Hb equal or more than age matched normal low limit with MCH <27 pg, and either Tfsat <10% or TIBC >360 microg/dL. The others were classified as normal control (NC).RESULTS: The proportion of IDA, ID and NC were 16.6% (7/42), 33.3% (14/42) and 50.0% (21/42), respectively. Comparisons of means of Hb, MCV, MCH, and RDW between groups showed statistical difference in general, while levels of iron, ferritin and hs-CRP showed no statistical difference. Mean blood levels of zinc protoporphyrin (ZnPP) of IDA, ID and NC were 72.21 microg/dL, 57.02 microg/dL, and 45.62 microg/dL, respectively, but the difference was significant only between IDA and NC. ZnPP was inversely correlated with MCV (r=-0.518, P<0.01) and RDW (r=-0.640, P<0.01), but not with hs-CRP or ferritin.CONCLUSION: Combination of RBC indices with newly controlled Tfsat or TIBC can be available for an iron status assessment in children with minor infections. ZnPP levels in blood reflect some aspect of iron status, while ferritin and iron do not reflect it.

Assessment of Iron Parameters in Children with Acute Infectious Disease / 임상소아혈액종양

BACKGROUND: As some parameters reflecting iron status were known to change with infection or inflammation, we examined the changes of these parameters in children with minor illnesses. METHODS: Hematologic tests were done in 42 young children with acute infection. Iron deficiency anemia (IDA) was defined as having Hb less than age-matched normal range, MCH 360 microg/dL. Iron deficiency (ID) was defined as having Hb equal or more than age matched normal low limit with MCH 360 microg/dL. The others were classified as normal control (NC). RESULTS: The proportion of IDA, ID and NC were 16.6% (7/42), 33.3% (14/42) and 50.0% (21/42), respectively. Comparisons of means of Hb, MCV, MCH, and RDW between groups showed statistical difference in general, while levels of iron, ferritin and hs-CRP showed no statistical difference. Mean blood levels of zinc protoporphyrin (ZnPP) of IDA, ID and NC were 72.21 microg/dL, 57.02 microg/dL, and 45.62 microg/dL, respectively, but the difference was significant only between IDA and NC. ZnPP was inversely correlated with MCV (r=-0.518, P<0.01) and RDW (r=-0.640, P<0.01), but not with hs-CRP or ferritin. CONCLUSION: Combination of RBC indices with newly controlled Tfsat or TIBC can be available for an iron status assessment in children with minor infections. ZnPP levels in blood reflect some aspect of iron status, while ferritin and iron do not reflect it.