Application of Machine Learning Approaches to Predict Postnatal Growth Failure in Very Low Birth Weight Infants

PurposeThe aims of the study were to develop and evaluate a machine learning model with which to predict postnatal growth failure (PGF) among very low birth weight (VLBW) infants.Materials and MethodsOf 10425 VLBW infants registered in the Korean Neonatal Network between 2013 and 2017, 7954 infants were included. PGF was defined as a decrease in Z score >1.28 at discharge, compared to that at birth. Six metrics [area under the receiver operating characteristic curve (AUROC), accuracy, precision, sensitivity, specificity, and F1 score] were obtained at five time points (at birth, 7 days, 14 days, 28 days after birth, and at discharge). Machine learning models were built using four different techniques [extreme gradient boosting (XGB), random forest, support vector machine, and convolutional neural network] to compare against the conventional multiple logistic regression (MLR) model.ResultsThe XGB algorithm showed the best performance with all six metrics across the board. When compared with MLR, XGB showed a significantly higher AUROC (p=0.03) for Day 7, which was the primary performance metric. Using optimal cut-off points, for Day 7, XGB still showed better performances in terms of AUROC (0.74), accuracy (0.68), and F1 score (0.67). AUROC values seemed to increase slightly from birth to 7 days after birth with significance, almost reaching a plateau after 7 days after birth.ConclusionWe have shown the possibility of predicting PGF through machine learning algorithms, especially XGB. Such models may help neonatologists in the early diagnosis of high-risk infants for PGF for early intervention.     

Monthly and seasonal variations in vestibular neuritis

Seasonal variations in vestibular neuritis (VN) could support the etiology of viral infection. However, several recent studies revealed no significant seasonal variations in VN. Further studies are necessary to determine the etiology of VN. We analyzed patients with VN to evaluate monthly and seasonal variations. Patients with VN who visited our otorhinolaryngology department or were referred to our department from the emergency department between March 2014 and February 2019 were included retrospectively in this study. Differences among the months and seasons of VN visits were analyzed. Patients were divided into 2 groups according to sex and age (65 years or older and younger than 65 years). Differences among the months and seasons of VN visits were analyzed between groups. There were no significant differences in monthly and seasonal distributions in 248 patients with VN. There were also no significant differences in monthly and seasonal distributions in male and female patients or in older and younger patients. There were no significant differences in monthly or seasonal distributions of patients with VN. Factors other than viruses, such as vascular ischemia, should also be considered in the incidence of VN, especially in older patients.     

Serial blood concentration of polyethoxylated tallow amine and clinical presentations in acute herbicide poisoning

<正>1Department of Emergency Medicine, Chungnam National University Hospital, Daejeon 35015, South Korea2Department of Emergency Medicine, College of Medicine, Chungnam National University, Daejeon 35015, South Korea3Forensic Toxicology Division, National Forensic Service, Daejeon 34054, South Korea4Department of Emergency Medicine, Chungbuk National University Hospital, Cheongju 28644, South Korea Corresponding Author:Wonjoon Jeong, Email:gardenjun@hanmail.net     

Sex-specific associations of obesity with exercise capacity and diastolic function in Koreans

Background and aimsWomen with obesity are highly predominant among patients with heart failure with preserved ejection fraction (HFpEF). We aimed to elucidate sex-specific associations of obesity with exercise capacity and diastolic function.Methods and resultsHealthy individuals without known cardiovascular diseases undergoing cardiopulmonary exercise test and echocardiography (n = 736) were included and categorized into 4 groups according to their sex and obesity. Exercise capacity was lower in women than men. Obesity was associated with a lower exercise capacity in women (23.5 ± 7.3 vs. 21.3 ± 5.4 ml/kg/min, p < 0.05) but not in men (28.2 ± 7.8 vs. 28.0 ± 6.6 ml/kg/min, p > 0.10). Overall, women had a higher E/e′ than men. Women without obesity had a similar E/e′ to men with obesity (8.2 ± 1.8 vs. 8.4 ± 2.1, p > 0.10), and women with obesity had the highest E/e′. Among 5 risk factors (aging, obesity, elevated blood pressure, elevated heart rate, and elevated fasting glucose), obesity was a significant determinant of exercise intolerance in women but not men. Furthermore, obesity was associated with a greater risk of diastolic dysfunction in women than men (women, adjusted odds ratio 4.35 [95% confidence interval 2.44–7.74]; men, adjusted odds ratio 2.91 [95% confidence interval 1.42–5.95]).ConclusionObesity had a more deleterious effect on exercise capacity and diastolic function in women than men, even in a healthy cohort. These subclinical changes might contribute to the development of a female predominance among HFpEF patients, particularly among individuals with obesity.     

Usefulness of Known Computed Tomography and Clinical Criteria for Diagnosing Strangulation in Small-Bowel Obstruction: Analysis of True and False Interpretation Groups in Computed Tomography

Computed tomography (CT) criteria have proven useful, but not sufficient, for diagnosis of bowel strangulation. The purpose of the present study was to evaluate the useof clinical criteria in the interpretation of CT scans as a means of improving the diagnostic accuracy of CT, especially in patients whose CT scans are equivocal for distinguishing simple obstruction from strangulated obstruction. We analyzed the CT scans of 136 patients with simple (n = 70) or strangulated (n = 66) small-bowel obstruction. Three radiologists interpreted the CT scans independently for the presence of intestinal strangulation. According to their interpretation, 136 patients were divided into two groups, i.e., a false and a true interpretation group. The diagnostic value of known CT and four clinical criteria (tenderness, tachycardia, fever, and leukocytosis) were compared in the two groups. The diagnostic accuracy of CT criteria for distinguishing simple obstructions from strangulated small-bowel obstructions ranged between 73% and 80%. Of the 136 patients, 31 belonged to the false group and 105 to the true group. The CT criteria that were highly specific in both groups included severe mesenteric haziness, serrated beak, and poor bowel wall enhancement. Among the clinical criteria, both tachycardia and leukocytosis were highly specific in both groups. The number of positive clinical criteria was helpful in making a diagnosis; none or one clinical criterion indicated a simple obstruction, whereas three or four criteria indicated a strangulated obstruction; when this result was applied retrospectively to the false group, the CT diagnostic accuracy improved in 19 of the 31 patients. The use of clinical criteria when CT findings are equivocal, may overcome the inherent limitations of CT for diagnosing strangulated small-bowel obstruction.     

Glucose starvation induces resistance to metformin through the elevation of mitochondrial multidrug resistance protein 1

Metformin, a drug for type 2 diabetes mellitus, has shown therapeutic effects for various cancers. However, it had no beneficial effects on the survival rate of human malignant mesothelioma (HMM) patients. The present study was performed to elucidate the underlying mechanism of metformin resistance in HMM cells. Glucose‐starved HMM cells had enhanced resistance to metformin, demonstrated by decreased apoptosis and autophagy and increased cell survival. These cells showed abnormalities in mitochondria, such as decreased ATP synthesis, morphological elongation, altered mitochondrial permeability transition pore and hyperpolarization of mitochondrial membrane potential (MMP). Intriguingly, Mdr1 was significantly upregulated in mitochondria but not in cell membrane. The upregulated mitochondrial Mdr1 was reversed by treatment with carbonyl cyanide m‐chlorophenyl hydrazone, an MMP depolarization inducer. Furthermore, apoptosis and autophagy were increased in multidrug resistance protein 1 knockout HMM cells cultured under glucose starvation with metformin treatment. The data suggest that mitochondrial Mdr1 plays a critical role in the chemoresistance to metformin in HMM cells, which could be a potential target for improving its therapeutic efficacy.     

The Effect of Campaign-Generated Interpersonal Communication on Campaign-Targeted Health Outcomes: A Meta-Analysis

This study examined the effect of mass media campaign-generated conversations on campaign-targeted health outcomes, via a systematic meta-analysis of 28 studies (including 124 sub-studies and a total of 138,898 participants). The study also conducted a series of moderation analyses to examine the conditions under which interpersonal communication has larger effects on bringing about the desired outcomes. The findings of this meta-analysis indicate that campaign-generated conversations have a positive effect on inducing campaign-targeted outcomes (OR = 1.28) and show that this effect is moderated by health topic addressed by the campaign, the type of outcome being targeted by the campaign, and with whom people converse, along with several other campaign-relevant and study-relevant variables. The implications of these findings for future research are discussed.