BACKGROUND: To prevent unsolved problems of medical devices, we hypothesized that combinatorial effects of zwitterionic functional group and anti-bacterial metal ions can reduce effectively the thrombosis and bacterial infection of polymeric biomaterials. In this research, we designed a novel series of zwitterionic polyurethane (zPU) additives to impart anti-thrombotic properties to a polyvinyl chloride (PVC) matrix. METHODS: We have synthesized zPUs by combination of various components and zPUs complexed with metal ions. Zwitterion group was prepared by reaction with 1,3-propane sultone and Nmethyldiethanolamine and metal ions were incorporated into sulfobetaine chains via molecular complexation. These zPU additives were characterized using FT-IR, 1H-NMR, elemental analysis, and thermal analysis. The PVC film blended with zPU additives were prepared by utilizing a solvent casting and hot melting process. RESULTS: Water contact angle demonstrated that the introduction of zwitterion group has improved hydrophilicity of polyurethanes dramatically. Protein adsorption test resulted in improved anti-fouling effects dependent on additive concentration and decreases in their effects by metal complexation. Platelet adhesion test revealed anti-fouling effects by additive blending but not significant as compared to protein resistance results. CONCLUSION With further studies, the synthesized zPUs and zPUs complexed with metal ions are expected to be used as good biomaterials in biomedical fields. Based on our results, we can carefully estimate that the enhanced anti-fouling effect contributed to reduced platelet adhesion.

The Korean Society of Nephrology (KSN) has published a clinical practice guideline (CPG) document for maintenance hemodialysis (HD). The document, 2021 Clinical Practice Guideline on Optimal HD Treatment, is based on an extensive evidence-oriented review of the benefits of preparation, initiation, and maintenance therapy for HD, with the participation of representative experts from the KSN under the methodologists’ support for guideline development. It was intended to help clinicians participating in HD treatment make safer and more effective clinical decisions by providing user-friendly guidelines. We hope that this CPG will be meaningful as a recommendation in practice, but not on a regulatory rule basis, as different approaches and treatments may be used by health care providers depending on the individual patient’s condition. This CPG consists of eight sections and 15 key questions. Each begins with statements that are graded by the strength of recommendations and quality of the evidence. Each statement is followed by a summary of the evidence supporting the recommendations. There are also a link to full-text documents and lists of the most important reports so that the readers can read further (most of this is available online).

The Korean Society of Nephrology (KSN) has published a clinical practice guideline (CPG) document for maintenance hemodialysis (HD). The document, 2021 Clinical Practice Guideline on Optimal HD Treatment, is based on an extensive evidence-oriented review of the benefits of preparation, initiation, and maintenance therapy for HD, with the participation of representative experts from the KSN under the methodologists’ support for guideline development. It was intended to help clinicians participating in HD treatment make safer and more effective clinical decisions by providing user-friendly guidelines. We hope that this CPG will be meaningful as a recommendation in practice, but not on a regulatory rule basis, as different approaches and treatments may be used by health care providers depending on the individual patient’s condition. This CPG consists of eight sections and 15 key questions. Each begins with statements that are graded by the strength of recommendations and quality of the evidence. Each statement is followed by a summary of the evidence supporting the recommendations. There is also a link to full-text documents and lists of the most important reports so that the readers can read further (most of this is available online).

OBJECTIVE: This study aimed to determine the efficacy of flexible pole training combined with lumbar stabilization in improving trunk muscle activities and to investigate the difference according to posture in young adults. METHODS: Twenty-five participants were enrolled in this study. The subjects were randomly allocated into either the flexible pole group or the rigid pole group. Participants performed lumbar stabilization exercises on quadruped and curl-up, with the flexible pole or rigid pole. Electromyography was used to assess the percent maximal voluntary isometric contracion (%MVIC) of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spine (ES) muscles. All participants completed one 30-minute session per day, 3 days per week, for 6 weeks. The evaluation was performed before and 6 weeks after the training, and follow-up. The data were analyzed using independent t-test and two-way repeated measure analysis of variance to determine the statistical significance. RESULTS: The flexible pole in curl-up showed significant differences in EO and IO muscle activities compared with the rigid pole. The flexible pole in quadruped showed significant differences in IO and ES muscle activities compared with the rigid pole. The RA, EO, IO, and ES muscle activities of both groups were significantly higher after 6 weeks training. CONCLUSION: The flexible pole in curl-up and quadruped showed an improvement in trunk muscle activation. The flexible pole combined with lumbar stabilization will be useful as an exercise tool to improve activity of trunk muscles.
Adult ; Electromyography ; Exercise ; Follow-Up Studies ; Humans ; Jupiter ; Muscles ; Posture ; Rectus Abdominis ; Spine ; Young Adult

BACKGROUND AND OBJECTIVES: Electrocardiography (ECG) is a cost-effective and useful method for diagnosing left ventricular hypertrophy (LVH) in a large-scale study or in clinical practice. Among ECG criteria, the Cornell product (Cor P) and Sokolow-Lyon criteria were adopted by the European Society of Hypertension-European Society of Cardiology Guidelines but have different performances among races. The aim of this study was to compare the diagnostic performance of two voltage criteria in Korean patients. SUBJECTS AND METHODS: Electrocardiography and echocardiographic LV mass of 332 (159 male, 173 female) consecutive patients were analyzed. Cornell voltage criteria and the Cor P were compared with Sokolow-Lyon voltage (Sok V) and the Sokolow-Lyon product (Sok P). The sensitivities and specificities were estimated using a receiver-operating characteristics (ROC) curve in relation to the LVH diagnosis. The sensitivities and revised cut-off values were derived at specificity levels of 90, 95, and 100%. RESULTS: The Cornell-based criteria generally showed better performance than that of the Sok V criteria and Sok P in the area under the ROC curve analysis. The revised cut-off values for the Cornell voltage criteria (20 and 16 mm for males and females, respectively) showed an improved sensitivity (19.7 and 30.3% for males and females, respectively), with a high specificity of 95%. CONCLUSION: The Cornell-based criteria had better performance than that of the Sokolow-Lyon criteria in both Korean men and women. However, revised cut-off values are needed to improve accuracy.
Cardiology ; Continental Population Groups ; Echocardiography ; Electrocardiography ; Female ; Humans ; Hypertrophy, Left Ventricular ; Male ; ROC Curve ; Sensitivity and Specificity

BACKGROUND AND OBJECTIVES: Ambulatory arterial stiffness index (AASI) is well known as a predictor of cardiovascular mortality in hypertensive patients. Mathematically, AASI reflect the standard deviation (SD) of blood pressure (BP) variation. AASI is measured higher levels in non-dipper than dipper. Thus, AASI has a possibility of not only reflecting arterial stiffness but also BP variability and/or autonomic nervous dysfunction. SUBJECTS AND METHODS: Consecutive data from 418 untreated hypertensive patients were analyzed retrospectively. We examined the association between the 24-hour ambulatory BP monitoring (ABPM) parameters and AASI. RESULTS: AASI had a simple correlation with age (R=0.189, p<0.001), relative wall thickness (RWT) (R=0.115, p=0.019), left ventricular mass index (LVMI) (R=0.192, p<0.001), average systolic BP (SBP) (R=0.232, p<0.001), average pulse pressure (PP) (R=0.363, p<0.001), SD of diastolic BP (DBP) (R=-0.352, p<0.001), SD of PP (R=0.330, p<0.001), SD of heart rate (HR) (R=-0.268, p<0.001), and nocturnal dipping (R=-0.137, p=0.005). In multiple linear regression analysis model including clinical parameters and 24 hour-ABPM parameters, independent predictors of AASI were SD of PP (beta=1.246, p<0.001), SD of DBP (beta=-1.067, p<0.001), SD of SBP (beta=-0.197, p<0.001), and non-dipper (beta=0.054, p=0.033). CONCLUSION: AASI is closely correlated with BP variability. The result of this study shows that AASI is not only a parameter for arterial stiffness, but also a parameter for BP variability.
Autonomic Nervous System Diseases ; Blood Pressure ; Blood Pressure Monitoring, Ambulatory ; Heart Rate ; Humans ; Linear Models ; Retrospective Studies ; Vascular Stiffness

BACKGROUND AND OBJECTIVES: Inappropriately high left ventricular mass (iLVM) is known to be related to cardiovascular prognosis. A non-dipper pattern has a greater mean left ventricular (LV) mass than the dipper pattern in hypertensive patients. However, the appropriateness of LV mass in dipper or non-dipper patterns has not been adequately investigated. The aim of this study was to define the relationship between nocturnal dipping and the appropriateness of LV mass. SUBJECTS AND METHODS: Using the ambulatory blood pressure monitoring (ABPM) database, the data of 361 patients who underwent ABPM and echocardiography was analyzed retrospectively. Appropriateness of LV mass was calculated as observed/predicted ratio of LV mass (OPR) using a Korean-specified equation. Nocturnal dipping was expressed as percent fall in systolic blood pressure (BP) during the night compared to the day. RESULTS: Daytime, nighttime and 24 hours BP in hypertensive patients was 140.4+/-14.8 mmHg, 143.7+/-15.2 mmHg and 129.4+/-20.0 mmHg, respectively. OPR was 106.3+/-19.9% and nocturnal dipping was 10.2+/-10.9 mmHg. In a multiple linear regression model, 24 hours systolic BP (beta=0.097, p=0.043) and nocturnal dipping (beta=-0.098, p=0.046) were independent determinants of OPR as well as age (beta=0.130, p=0.025) and body mass index (BMI) (beta=0.363, p<0.001). Odds ratio of the non-dipper pattern was 2.134 for iLVM (p=0.021) and 3.694 for obesity (p<0.001; BMI >25 kg/m2). CONCLUSION: The non-dipper pattern is independently associated with iLVM in hypertensive patients as well as obesity.
Blood Pressure ; Blood Pressure Monitoring, Ambulatory ; Body Mass Index ; Echocardiography ; Humans ; Hypertension ; Hypertrophy, Left Ventricular ; Linear Models ; Obesity ; Odds Ratio ; Prognosis ; Retrospective Studies

PURPOSE: Although the quality of life (QoL) of prostate cancer (PCa) patients is a major issue, there is no unified and useful methodology for assessing QoL. The Expanded Prostate Cancer Index Composite (EPIC) is a globally used tool to measure QoL after PCa treatment that comprises urinary, bowel, sexual, and hormonal domains. Acknowledging the need for such a tool applicable to Korean PCa patients, we translated EPIC into Korean and validated the new version. MATERIALS AND METHODS: The Korean version of EPIC was devised by translation, back-translation, and reconciliation. Subsequently, we randomly selected 153 patients with localized PCa treated with radical perineal prostatectomy (67, 43.8%), radical retropubic prostatectomy (19, 12.4%), laparoscopic radical prostatectomy (12, 7.8%), robot-assisted laparoscopic radical prostatectomy (36, 23.5%), and high-intensity focused ultrasound ablation of the prostate (19, 12.4%) and asked them to complete EPIC. Reliability was assessed by test-retest correlation and Cronbach's alpha. Validity was assessed by factor analysis, interscale correlation, and correlation with Functional Assessment of Cancer Therapy-Prostate (FACT-P). RESULTS: Test-retest correlation and Cronbach's alpha were high in each of the domains (0.92, 0.91, 0.76, 0.84 and 0.86, 0.84, 0.92, 0.83, p<0.0001). Interscale correlation among the domains was low (r<0.37), which indicated that EPIC is composed of proper domains. Interscale correlation between the function and bother subscales was high (0.94, 0.81, 0.84 and 0.80, p<0.0001). EPIC domains had low correlation with FACT-P, permitting complementary use. CONCLUSIONS: The Korean version of EPIC was developed by a proper process, as evident by its high reliability and validity. Therefore, it is a reliable, comprehensive, systematic method that evaluates QoL in Korean patients after PCa treatment. Furthermore, it can be adapted as an objective methodology for research globally.
High-Intensity Focused Ultrasound Ablation ; Humans ; Passive Cutaneous Anaphylaxis ; Prostate ; Prostatectomy ; Prostatic Neoplasms ; Quality of Life ; Reproducibility of Results

BACKGROUND AND OBJECTIVES: The structural significance of the inappropriateness of left ventricular mass (iLVM) is known to be an important prognostic factor for cardiovascular events; however, the functional changes associated with iLVM have not been established. This study was performed to determine if diastolic dysfunction is associated with iLVM using a tissue Doppler technique. SUBJECTS AND METHODS: Three hundred sixty consecutive subjects, including 221 hypertension patients from the echocardiography database, were analyzed. Regarding the appropriateness of left ventricular (LV) mass, an observed/predicted ratio of LV mass (OPR) >130% was defined as inappropriate. Echocardiographic parameters, including early diastolic peak velocity (E)/late diastolic peak velocity (A), deceleration time (DT), isovolumetric relaxation time (IVRT), and E/early mitral annulus velocity (E'), were compared between the appropriate LV mass (aLVM) group and the iLVM group. RESULTS: Among transmitral flow parameters, only the E velocity was negatively correlated with the OPR when adjusted for age (adjusted r=-0.107, p=0.04). Based on multiple regression analysis, the OPR (beta=0.163, p=0.003), as well as age (beta=0.286, p=0.0001), systolic blood pressure (beta=0.120, p=0.019), fasting blood glucose (beta=0.098, p=0.042), and male gender (beta=0.157, p=0.002) were independent factors determining E/E'. The cholesterol level was not an independent factor (beta=-0.059, p=0.355). In the iLVM group (n=105), the adjusted E/E' was higher than in the aLVM group (n=255; 11.7+/-3.4 vs. 10.8+/-3.1, p=0.02), while the peak E flow velocity was significantly lower than in the aLVM group (70.9+/-15.1 vs. 75.5+/-17.6, p=0.03). CONCLUSION: Inappropriateness of LV mass is independently associated with increased E/E'. Thus, E/E' may be a useful parameter for the evaluation of diastolic dysfunction.
Blood Glucose ; Blood Pressure ; Cholesterol ; Deceleration ; Echocardiography ; Fasting ; Heart Ventricles ; Humans ; Hypertension ; Hypertrophy ; Male ; Relaxation

PURPOSE: To date, it has been impossible to relate the occurrence of ventricular arrhythmia to survival in hyperkalemia. QT dispersion is thought to reflect the inhomogeneity of ventricular repolarization and to be related to ventricular-arrhythmia-induced sudden cardiac death in various medical conditions. Therefore, the purpose of this study was to investigate to use QT dispersion as a prognostic marker in hyperkalemia and to suggest treatment guidelines for hyperkalemia by analyzing the correlations between the QT dispersion on the initial ECG and the treatment outcomes. METHODS: This study's population was comprised of 104 patients with serum potassium concentrations > or =5.5 mEq/L, who were divided into 2 groups; group 1 was the survival group (n=81), group 2 was the death group (n=23). We reviewed retrospectively the underlying diseases, electrolytes, treatment outcomes and the clinical and ECG findings during the initial and the recovery states. The QT interval for each lead was measured manually on an enlarged (X1.5) ECG. The QT interval was measured from the first deflection of the QRS complex to the point of the T wave offset, and the corrected QT interval was obtained by using B a z e t t's formula. The QT dispersion and the corrected QT dispersion were defined as the differences between the minimal and the maximal QT values and between the corresponding corrected QT values for each of the 12 leads, respectively. RESULTS: The treatment outcomes were not related to the initial serum potassium and the hourly serum potassium change rates. For hyperkalemia > or =7.0 mEq/L, the death group had significantly larger QT dispersion than the survival group (death group = 95.6+/-15.4 msec, survival group = 51.8+/-17.5 msec, p<0.01). However, the QT dispersions of the two groups were not different for serum potassium levels <7.0 mEq/L. For hyperkalemia > or =7.0mEq/L, QT dispersion above 65 msec had a 93.8% sensitivity, a 79.4% specificity, and a 68.2% positive predictive value for death. CONCLUSION: For hyperkalemia > or =7.0 mEq/L, QT dispersion above 65 msec should be considered to be a prognostic marker for prediction of the treatment outcome.
Arrhythmias, Cardiac ; Death, Sudden, Cardiac ; Electrocardiography ; Electrolytes ; Humans ; Hyperkalemia* ; Potassium ; Prognosis ; Retrospective Studies ; Sensitivity and Specificity ; Treatment Outcome