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    An intelligent system for the classification of postoperative pleural effusion between 4 and 30 days using medical knowledge discovery
    (Scientific Publishers of India, 2017) Guldogan E.; Arslan A.K.; Colak M.C.; Colak C.; Erdil N.
    Objective: Pleural Effusion (PE) is a considerable and a common health problem. The classification of this condition is of great importance in terms of clinical decision making. The purpose of the study is to design an intelligent system for the classification of postoperative pleural effusion between 4 and 30 days after surgery by medical knowledge discovery (MKD) methods. Materials and methods: This study included 2309 individuals diagnosed with coronary artery disease for elective coronary artery bypass grafting (CABG) operation. The results of chest x-ray were used to diagnose PE. The subjects were allocated to two groups: PE group (n=81) and non-PE group (n=2228), consecutively. In the preprocessing step, outlier analysis, data transformation and feature selection processes were performed. In the data mining step, Naïve Bayes, Bayesian network and Random Forest algorithms were utilized. Accuracy and area under receiver operating characteristics (ROC) curve (AUC) were calculated as evaluation metrics. Results: In the preprocessing step, 85 outlier observations were removed from the study. The rest of the data consisted of 2224 subjects: 2149 of these individuals were in non-PE group, and the 75 were in PE group. Random Forest yielded the best classification performance with 97.45% of accuracy and 0.990 of AUC for 0.7 of the optimal split ratio by Grid search algorithm. Conclusion: The achieved results pointed out that the best classification performance was obtained from the RF ensemble model. Therefore, the suggested intelligent system can be used as a clinical decision making tool. © 2017, Scientific Publishers of India. All rights reserved.
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    Perioperative high-dose amiodarone elevates nitric oxide levels in patients undergoing coronary artery bypass surgery
    (2013) Uysal A.; Azak S.; Colak M.C.; Burma O.; Ozguler I.M.; Ustundag B.; Bayar M.K.
    The aim of the current study was to assess the effects of the Class III antiarrhythmic drug amiodarone on arterial blood Nitric oxide (NO) levels together with malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-px), and catalase (CAT) levels in patients undergoing coronary artery bypass surgery (CABG). Twenty patients undergoing CABG were included in the study. The patients were divided into control and amiodarone groups (n=10 in each group). The patients in group 1 did not receive any drugs. The patients in group II received 4X400 mg/day amiodarone on the day before surgery, 2X600 mg/day amiodarone on the day of surgery, and 2X400 mg/day amiodarone for the first consecutive four days after the surgery. NO, MDA, SOD, GSH-px, and CAT values were measured for biochemical evaluation of oxidative stress before the induction of anesthesia (TA), before CPB (TCPB), five minutes after the clamp was removed (Tc), after pro-tamine (TP), and on postoperative days 1 (T1), 3 (T3), and 5 (T5). Hemodynamic changes of all patients were recorded at before the induction of anesthesia (TA), before CPB (TCPB), after protamine (TP), and on postoperative day 1 (T1). Amiodarone elevated NO levels at all times during the study period but did not cause changes in MDA, SOD, GSH-px, or CAT. In addition, amiodarone decreased mean pulmonary artery pressure, pulmonary capillary wedge pressure, and heart rate in these patients. No side effect due to drug was observed. Heart rate was found more decreased in amiodarone group at T1 and T2 stages when compared with controls (p<0.05). Perioperative high-dose amiodarone might be beneficial for patients who are pulmonary hypertensive and are undergoing CABG.