OBJECTIVES: Breast cancer is the second most common cancer among Korean women. Because breast cancer is strongly associated with negative emotional and physical changes, early detection and treatment of breast cancer are very important. As a supporting tool for classifying breast cancer, we tried to identify the best meta-learner model in a stacking ensemble when the same machine learning models for the base learner and meta-learner are used. METHODS: We used machine learning models, such as the gradient boosted model, distributed random forest, generalized linear model, and deep neural network in a stacking ensemble. These models were used to construct a base learner, and each of them was used as a meta-learner again. Then, we compared the performance of machine learning models in the meta-learner to determine the best meta-learner model in the stacking ensemble. RESULTS: Experimental results showed that using the GBM as a meta-learner led to higher accuracy than that achieved with any other model for breast cancer data and using the GLM as a meta learner led to low root-mean-squared error for both sets of breast cancer data. CONCLUSIONS: We compared the performance of every meta-learner model in a stacking ensemble as a supporting tool for classifying breast cancer. The study showed that using specific models as a metalearner resulted in better performance than single classifiers, and using GBM and GLM as a meta-learner is appropriate as a supporting tool for classifying breast cancer data.
Breast Neoplasms ; Breast ; Classification ; Female ; Forests ; Humans ; Linear Models ; Machine Learning ; Medical Informatics ; Statistics as Topic

Sirtuins (SIRTs) are involved in multiple cellular processes including those related to aging, cancer, and a variety of cellular functions including cell cycle progression, DNA repair, and cellular proliferation. SIRTs have been shown to extend the yeast life span, although there is presently little known about SIRT expression in the organs of mice. In the present study, we were especially interested in identifying differences in SIRT expression between young mice and aged mice. Specifically, we investigated the expression of SIRT1 and SIRT3 in the kidney, lung, skin, adipose tissue, and spleens of 6-month-old and 24-month-old mice using immunohistochemical staining. Compared with that in younger mice, the expression of SIRT1 in 24-month-old rats was increased in kidney, lung, and spleen tissue, while that of SIRT3 was decreased in adipose, kidney, and lung tissue. The results of our study suggest that aging is associated with altered patterns of expression of SIRT1 and SIRT3. In addition, we noted that the expression patterns of SIRT1 and SIRT3 varied by organ. Taken together, the results of this study suggest the possibility that SIRTs may be involved in diseases associated with aging.
Adipose Tissue ; Aging ; Animals ; Cell Cycle ; Cell Proliferation ; Child, Preschool ; DNA Repair ; Humans ; Immunohistochemistry ; Infant ; Kidney ; Lung ; Mice* ; Rats ; Sirtuins ; Skin ; Spleen ; Yeasts

Sirtuins (SIRTs) are involved in multiple cellular processes. And they are involved in cellular pathways related aging, cancer, and a variety of cellular functions including cell cycle, DNA repair and proliferation. Also they modulate life span. Stem cells have the ability to self-renew for unlimited proliferation and differentiate into various cell types. It has been a little known that the mutation of undifferentiated stem cells in tissue may result in the development of cancer cells by genotoxic carcinogens. Therefore, this study investigated whether some carcinogenic compounds can modulate the expression of sirtuin mRNA on human adipose-derived stem cells. Adipose-derived stem cells (ADSC) were exposed to genotoxic carcinogenic compound (2-nitrofluorene, 2NF) and non-genotoxic carcinogenic compound (clonidine, CND) for 24 hours, 48 hours, 72 hours and 96 hours. The expression of SIRT1 mRNA increased on 72 hours. Expressions of SIRT2 and SIRT7 mRNA increased robustly on 48 hours. But all of SIRTs decreased to a level before a treatment of genotoxic compound on adipose-derived stem cells. These results demonstrated that a treatment of genotoxic compound induced the expression of SIRT mRNA only in the short time. But their level returned to untreated cells on 96 hours. They suggest that the possibility that the sirtuins can retard the carcinogenesis of adipose derived stem cells.
Aging ; Carcinogenesis ; Carcinogens ; Cell Cycle ; Clonidine* ; DNA Repair ; Humans ; RNA, Messenger* ; Sirtuins ; Stem Cells*

Objective: The ratio of 2nd and 4th digit length (2D:4D) is considered to be a sexually dimorphic trait. Low 2D:4D is implicated in alcohol dependence and heroin dependence and correlated with psychological traits such as aggression, physical aggression, and sensation. The purpose of this study is to compare the 2D:4D between methamphetamine (METH) dependence and controls and the 2D:4D ratio that is a potential biomarker for METH dependence. Methods: In this study, 40 patients diagnosed with METH dependence in Eulji University Gangnam Eulji Hospital and 50 healthy volunteers were all employees in the same hospital. Images of participants’ hands were created using a scanning device. The images contained both the right and left hands; computer software was used to measure the 2D:4D ratio for both hands. We compared the ratios, analyzed by t test, between the METH dependence group and the control group. Results: The mean 2D:4D values were 0.941 (right hand) and 0.943 (left hand) for the patients with METH dependence; in contrast, they were 0.961 (right hand) and 0.961 (left hand) for the control group. These values were significantly smaller than the control in patients’ right hands (p = 0.003) and left hands (p = 0.012). Conclusion Patients with METH dependence had smaller 2D:4D ratios than those in the control group, which is similar to the results from the previous substance use disorder studies. Thus, elevated prenatal testosterone levels during the gonadal period could be related to future METH problems. Furthermore, the 2D:4D ratio is a potential marker for the prediction of METH dependence.

PURPOSE: The aim of this study was to investigate the clinical characteristics and causative organisms of meningitis in the Daegu region and seek a useful tool for the early prediction of bacterial meningitis in children. METHODS: We retrospectively reviewed the medical records of 115 pediatric patients diagnosed with bacterial or aseptic meningitis at Yeungnam university hospital in Daegu from March 2012 to July 2013. We evaluated their clinical symptoms, laboratory findings, clinical courses, bacterial meningitis scores and complications. RESULTS: The subjects included 106 with aseptic meningitis and 9 with bacterial meningitis. At the time of visit, fever was the most frequent symptom, followed by headache, vomiting and neck stiffness. In cerebrospinal fluid (CSF) analysis, white blood cell (WBC) count were higher in the bacterial meningitis group (1423.8+/-1980.4 vs. 120.0+/-161.6 mg/dL). Mean CSF protein was 219.4+/-183.6 mg/dL in bacterial meningitis and 42.4+/-27.0 mg/dL in aseptic meningitis (P <0.001). Bacterial meningitis score (BMS) were higher in the group with bacterial meningitis. Abnormal radiological findings were found in 44% of the group with bacterial meningitis. CONCLUSION: Although the clinical features between the groups were similar, the CSF analysis revealed significant differences statistically. Furthermore, BMS could be helpful to predict bacterial meningitis in children. During the outbreak of aseptic meningitis, it might reduce unnecessary hospital admissions and antibiotic treatments.
Cerebrospinal Fluid ; Child ; Daegu ; Fever ; Headache ; Humans ; Leukocytes ; Medical Records ; Meningitis ; Meningitis, Aseptic* ; Meningitis, Bacterial ; Neck ; Retrospective Studies ; Vomiting

BACKGROUND: The activation of guanine nucleotide binding protein-coupled receptors, such as adenosine receptor (ADR) and opioid receptor (OPR), protects the heart against ischemia and reperfusion injury. We hypothesized that ADR or OPR might be involved in polyphenol (-)-epigallocatechin gallate (EGCG)-induced cardioprotection. METHODS: Langendorff perfused rat hearts were subjected to 30 min of regional ischemia and 2 h of reperfusion. Hearts were treated with 10 microM of EGCG, with or without the ADR or OPR antagonist at early reperfusion. Infarct size measured with 2,3,5-triphenyltetrazolium chloride staining was chosen as end-point. RESULTS: EGCG significantly reduced infarct volume as a percentage of ischemic volume (33.5 +/- 4.1%) compared to control hearts (14.4 +/- 1.1%, P < 0.001). A nonspecific ADR antagonist 8-(p-sulfophenyl) theophylline hydrate (27.1 +/- 1.9%, P < 0.05 vs. EGCG) but not a nonspecific OPR antagonist naloxone (14.3 +/- 1.3%, P > 0.05 vs. EGCG) blocked the anti-infarct effect by EGCG. The infarct reducing effect of EGCG was significantly reversed by 200 nM of the A1 ADR antagonist DPCPX (25.9 +/- 1.1%, P < 0.05) and 15 nM of the A2B ADR antagonist MRS1706 (29.3 +/- 1.7%, P < 0.01) but not by 10 microM of the A2A ADR antagonist ZM241385 (23.9 +/- 1.9%. P > 0.05 vs. EGCG) and 100 nM of the A3 ADR antagonist MRS1334 (24.1 +/- 1.8%, P > 0.05). CONCLUSIONS: The infarct reducing effect of EGCG appears to involve activation of ADR, especially A1 and A2B ADR, but not OPR.
Adenosine ; Animals ; Catechin ; Guanine ; Heart ; Ischemia ; Myocardial Infarction ; Naloxone ; Purines ; Rats ; Receptors, Opioid ; Receptors, Purinergic P1 ; Reperfusion ; Reperfusion Injury ; Tetrazolium Salts ; Theophylline ; Triazines ; Triazoles ; Xanthines

Objective: To elucidate whether clinical features and the weighted genetic risk score (wGRS) were associated with the presence of lupus nephritis (LN). Methods: We retrospectively divided patients with systemic lupus erythematosus (SLE, n=1,078) into biopsy-proven LN (n=507) and non-LN groups (non-LN, n=571). Baseline clinical features, serologic markers, and the wGRS were collected. The wGRS was calculated from 112 non-human leukocyte antigen (non-HLA) loci and HLA-DRβ1 amino acid haplotypes for SLE. Associations among clinical features, wGRS, and the presence of LN were identified. Results: In the multivariate analysis, patients with LN were younger at diagnosis (odds ratio [OR]=0.97, p＜0.001), had more pleuritis (OR=2.44, p＜0.001) and pericarditis (OR=1.62, p=0.029), had a higher detection rate of anti-double stranded deoxyribonucleic acid (anti-dsDNA antibodies, OR=2.22, p＜0.001), anti-Smith antibodies (anti-Sm antibodies, OR=1.70, p=0.002), low level of complement (OR=1.37, p=0.043) and absence of antiphospholipid antibodies (aPL antibodies, OR=1.60, p=0.002), and had higher wGRS (OR=1.16, p=0.012). Mediation analysis suggested that anti-Sm antibodies and low complement could be mediators in the relationship between high wGRS and the presence of LN. Conclusion Onset age, pleuritis, pericarditis, several serologic markers, and wGRS were associated with the presence of LN. Anti-Sm antibodies and low complement appeared to mediate the indirect relationship between wGRS and the presence of LN.

Objective: To elucidate whether clinical features and the weighted genetic risk score (wGRS) were associated with the presence of lupus nephritis (LN). Methods: We retrospectively divided patients with systemic lupus erythematosus (SLE, n=1,078) into biopsy-proven LN (n=507) and non-LN groups (non-LN, n=571). Baseline clinical features, serologic markers, and the wGRS were collected. The wGRS was calculated from 112 non-human leukocyte antigen (non-HLA) loci and HLA-DRβ1 amino acid haplotypes for SLE. Associations among clinical features, wGRS, and the presence of LN were identified. Results: In the multivariate analysis, patients with LN were younger at diagnosis (odds ratio [OR]=0.97, p＜0.001), had more pleuritis (OR=2.44, p＜0.001) and pericarditis (OR=1.62, p=0.029), had a higher detection rate of anti-double stranded deoxyribonucleic acid (anti-dsDNA antibodies, OR=2.22, p＜0.001), anti-Smith antibodies (anti-Sm antibodies, OR=1.70, p=0.002), low level of complement (OR=1.37, p=0.043) and absence of antiphospholipid antibodies (aPL antibodies, OR=1.60, p=0.002), and had higher wGRS (OR=1.16, p=0.012). Mediation analysis suggested that anti-Sm antibodies and low complement could be mediators in the relationship between high wGRS and the presence of LN. Conclusion Onset age, pleuritis, pericarditis, several serologic markers, and wGRS were associated with the presence of LN. Anti-Sm antibodies and low complement appeared to mediate the indirect relationship between wGRS and the presence of LN.