Research using experimental animals has substantially contributed to advances in science and medicine. Animal experiments are nearly essential for biomedical research and development efforts. Because many animals are sacrificed, researchers should consider the welfare of experimental animals and related ethical issues, along with the successful results of their experiments. This review introduces the criteria that should be considered in terms of experimental animal ethics, based on the principles of the 3 R’s: replacement, representing careful consideration of the need for animal experiments; reduction, representing the use of the minimal number of animals to obtain meaningful experimental results; and refinement, representing continuous effects to find alternative methods to reduce pain and distress in experimental animals. Based on these principles, the following points should be considered when planning experiments: the necessity of animal experiments; alternatives to animal experiments; the relevance of the species and numbers of experimental animals; appropriate assessment and management of pain; the proper usage of sedatives, painkillers, and anesthesia; and valid timing for humane endpoints and euthanasia. These criteria are beneficial for both experimental animals and researchers because careful handling to ensure experimental animal welfare guarantees that scientific research will yield convincing, repeatable, and accurate results.

PURPOSE: The purpose of this study was to identify non-psychiatric nurses' difficulties in caring for patients with mental illness. METHODS: Data were collected from eighteen general medical-surgical nurses working at a university hospital in Seoul, Korea. This study involved two focus group discussions and three in-depth individual interviews. All interviews were recorded and transcribed as they were spoken, and data were analyzed using qualitative content analysis. RESULTS: General medical-surgical nurses experienced difficulties in 3 categories, 9 subcategories, 27 codes. The three categories were ‘nurse’ related factors, ‘patient’ related factors, ‘resource’ related factors. The nine categories were ‘unpreparedness’, ‘nursing barriers due to stigma’, ‘undervaluing and avoidance of psychiatric nursing’, ‘eroding into the trap of a vicious cycle’, ‘facing unapproachable patients’, ‘dealing with unhelpful family members’, ‘burdening already overburdened staff’, ‘obstructive environment’, and ‘isolation of staff with heavy responsibilities’. CONCLUSION: The results of this study indicate the need to develop psychiatric mental health education programs for non-psychiatric nurses. Education about psychiatric mental health and support from institutions for non-psychiatric nurses can reduce their negative attitude toward psychiatric patients and difficulties in caring for psychiatric patients.
Education ; Focus Groups ; Humans ; Korea ; Medical-Surgical Nursing ; Mental Disorders ; Mental Health ; Psychiatric Nursing ; Qualitative Research ; Seoul

BACKGROUND: The aim of this study is to evaluate the effect of depression, anxiety, and optimism on postoperative satisfaction and clinical outcomes in patients who underwent less than two-level posterior instrumented fusions for lumbar spinal stenosis and degenerative spondylolisthesis. METHODS: Preoperative psychological status of subjects, such as depression, anxiety, and optimism, was evaluated using the Hospital Anxiety and Depression Scale (HADS) and the Revised Life Orientation Test (LOT-R). Clinical evaluation was determined by measuring changes in a visual analogue scale (VAS) and the Oswestry Disability Index (ODI) before and after surgery. Postoperative satisfaction of subjects assessed using the North American Spine Society lumbar spine questionnaire was comparatively analyzed against the preoperative psychological status. The correlation between patient's preoperative psychological status (depression, anxiety, and optimism) and clinical outcomes (VAS and ODI) was evaluated. RESULTS: VAS and ODI scores significantly decreased after surgery (p < 0.001), suggesting clinically favorable outcomes. Preoperative psychological status of patients (anxiety, depression, and optimism) was not related to the degree of improvement in clinical outcomes (VAS and ODI) after surgery. However, postoperative satisfaction was moderately correlated with optimism. CONCLUSIONS: Anxiety and optimism were more correlated with patient satisfaction than clinical outcomes. Accordingly, the surgeon can predict postoperative satisfaction of patients based on careful evaluation of psychological status before surgery.
Anxiety* ; Cohort Studies* ; Depression* ; Humans ; Optimism* ; Patient Satisfaction ; Spinal Stenosis* ; Spine ; Spondylolisthesis*

BACKGROUND: Type 2 diabetes mellitus is associated with an increased risk of osteoporotic fracture despite relatively preserved bone mineral density (BMD). Although this paradox might be attributed to the influence of insulin resistance (IR) on bone structure and material properties, the association of IR with femur bone geometry and strength indices remains unclear. METHODS: Using data from the Cardiovascular and Metabolic Disease Etiology Research Center cohort study, we conducted a cross-sectional analysis among nondiabetic postmenopausal women. IR was estimated using the homeostasis model assessment of IR (HOMA-IR). Compartment-specific volumetric BMD (vBMD) and bone volume of proximal femur were measured using quantitative computed tomography. The compressive strength index (CSI), section modulus (Z), and buckling ratio of the femoral neck were calculated as bone strength indices. RESULTS: Among 1,008 subjects (mean age, 57.3 years; body mass index [BMI], 23.6 kg/m²), BMI, waist circumference, and vBMD of the femoral neck and total hip increased in a linear trend from the lowest ( < 1.37) to highest (≥2.27) HOMA-IR quartile (P < 0.05 for all). The HOMA-IR showed an independent negative association with total bone volume (standardized β=−0.12), cortical volume (β=−0.05), CSI (β=−0.013), and Z (β=−0.017; P < 0.05 for all) of the femoral neck after adjustment for age, weight, height, physical activity, and vitamin D and high-sensitivity C-reactive protein levels. However, the association between HOMA-IR and vBMD was attenuated in the adjusted model (femoral neck, β=0.94; P=0.548). CONCLUSIONS: Elevated HOMA-IR was associated with lower cortical bone volume and bone strength indices in nondiabetic postmenopausal women, independent of age and body size.
Body Mass Index ; Body Size ; Bone Density ; C-Reactive Protein ; Cohort Studies ; Compressive Strength ; Cross-Sectional Studies ; Diabetes Mellitus, Type 2 ; Female ; Femur Neck ; Femur* ; Hip ; Homeostasis ; Humans ; Insulin Resistance* ; Insulin* ; Metabolic Diseases ; Motor Activity ; Neck ; Osteoporosis ; Osteoporotic Fractures ; Postmenopause ; Vitamin D ; Waist Circumference

PURPOSE: Elderly patients (pts) (EPs; > or = 65 years old) with newly diagnosed-acute decompensated heart failure (ND-ADHF) have not yet been studied. The aim of the present study was to investigate clinical characteristics, including echocardiographic findings and prognosis, for EPs with ND-ADHF and to compare those with non-elderly pts (NEPs). MATERIALS AND METHODS: We retrospectively investigated 256 pts (144 males, 63.0 +/- 14.8 years old) who were admitted to our hospital between January 2005 and March 2009 with ND-ADHF. Clinical characteristics and echocardiographic parameters were analyzed in EPs (n = 135, 58 males) and NEPs (n = 121, 86 males). RESULTS: In intergroup comparison, female gender, diabetes mellitus, previous stroke and hypertension were more common in EPs. Body mass index (22.3 +/- 4.5 vs. 24.0 +/- 4.4 kg/m2), estimated glomerular filtration rate (54.8 +/- 24.3 vs. 69.2 +/- 30.7 mL/min/m2), C-reactive protein (28.5 +/- 46.9 vs. 7.6 +/- 11.6 mg/dL), hemoglobin (12.3 +/- 2.1 vs. 13.6 +/- 2.3 g/dL) and N-terminal pro-brain natriuretic peptide level (10,538.2 +/- 10,942.3 vs. 6,771.0 +/- 8,964.7 pg/mL) were significantly different (p < 0.05 for all). Early mitral inflow velocity to early diastolic mitral annular velocity (E/E') was significantly higher in EPs than in NEPs (21.2 +/- 9.4 vs. 18.0 +/- 8.9, p < 0.05). During follow-up (44.7 +/- 14.5 months), there were no significant differences in in-hospital mortality, re-hospitalization and cardiovascular mortality between EPs and NEPs (p = NS for all). CONCLUSION: EPs with ND-ADHF have different clinical characteristics and higher LV filling pressure when compared with NEPs. However, the clinical outcomes for NEPs with ND-ADHF are not necessarily more favorable than those for EPs.
Aged ; Echocardiography/*methods ; Female ; Heart Failure/*diagnosis/*epidemiology ; Humans ; Male ; Middle Aged ; Retrospective Studies

Background: Cardiac resynchronization therapy (CRT) is an effective treatment option for patients with heart failure (HF) and left ventricular (LV) dyssynchrony. However, the problem of some patients not responding to CRT remains unresolved. This study aimed to propose a novel in silico method for CRT simulation. Methods: Three-dimensional heart geometry was constructed from computed tomography images. The finite ele‑ ment method was used to elucidate the electric wave propagation in the heart. The electric excitation and mechani‑ cal contraction were coupled with vascular hemodynamics by the lumped parameter model. The model parameters for three-dimensional (3D) heart and vascular mechanics were estimated by matching computed variables with measured physiological parameters. CRT effects were simulated in a patient with HF and left bundle branch block (LBBB). LV end-diastolic (LVEDV) and end-systolic volumes (LVESV), LV ejection fraction (LVEF), and CRT responsiveness measured from the in silico simulation model were compared with those from clinical observation. A CRT responder was defined as absolute increase in LVEF ≥ 5% or relative increase in LVEF ≥ 15%. Results: A 68-year-old female with nonischemic HF and LBBB was retrospectively included. The in silico CRT simu‑ lation modeling revealed that changes in LVEDV, LVESV, and LVEF by CRT were from 174 to 173 mL, 116 to 104 mL, and 33 to 40%, respectively. Absolute and relative ΔLVEF were 7% and 18%, respectively, signifying a CRT responder.In clinical observation, echocardiography showed that changes in LVEDV, LVESV, and LVEF by CRT were from 162 to 119 mL, 114 to 69 mL, and 29 to 42%, respectively. Absolute and relative ΔLVESV were 13% and 31%, respectively, also signifying a CRT responder. CRT responsiveness from the in silico CRT simulation model was concordant with that in the clinical observation. Conclusion This in silico CRT simulation method is a feasible technique to screen for CRT non-responders in patients with HF and LBBB.

Objective: To develop a set of reference standards for tibial motor, common peroneal motor, sural sensory, and superficial peroneal sensory nerve conduction studies (NCSs) with expanded uncertainty in a healthy Korean population. Methods: Standardized procedures were conducted for individual lower extremity NCSs of 199 healthy participants in their 20s (n=100) and 50s (n=99). Mean values and expanded uncertainties for parameters were analyzed with thorough consideration of multiple uncertainty factors under the International Guide to the Expression of Uncertainty in Measurement. In addition, side-to-side differences in onset latency, amplitude, and nerve conduction velocity (NCV) were analyzed. Results: Mean (reference range) for distal onset latency, baseline to negative peak amplitude, NCV of tibial motor nerve in males in their 20s were 4.3 ms (3.1–5.4 ms), 7.1 mV (3.4–10.9 mV), and 50.7 m/s (42.2–59.3 m/s), respectively; sural sensory nerve baseline to negative peak amplitude in males in their 20s was 21.7 μV (8.3–35.2 μV). Including the aforementioned data, we present a vast dataset of normative mean values and expanded uncertainties for NCSs of the leg in a healthy Korean population. Furthermore, upper limits for normal side-to-side differences for onset latency, amplitude, and NCV of each nerve are suggested. Conclusion To our knowledge, this is the first study to present the reference standards of leg NCSs with consideration for multifactorial uncertainties in an Asian population. We expect these results to help practitioners make reliable and reproducible clinical decisions.

Background: Angiotensin type II receptor blockers (ARBs) are the most widely used antihypertensive drugs. This study aimed to elucidate the likelihood and pattern of ARB-induced liver injury in a hospital-based cohort. Methods: Data of patients receiving fimasartan (n = 5,543), candesartan (n = 6,406), valsartan (n = 6,040), and losartan (n = 9,126) were retrieved from the clinical data warehouse of two tertiary hospitals. Patients with alanine aminotransferase (ALT) levels > 5 times the upper normal limit were assessed according to the Roussel Uclaf Causality Assessment Method (RUCAM). Results: A total of 27,115 patients were enrolled, including 14,630 (54.0%) men, with a mean age of 64.6 years (standard deviation, 13.6). During 31,717 person-years of ARB therapy, serum ALT levels > 120 IU/L were found in 558 (2.1%) person-years, and levels > 200 IU/L were found in 155 (0.6%) person-years. The incidence of ALT elevation > 120 IU/L per 10 6cumulative defined daily doses was 6.6, 3.6, 3.9, and 4.0 in the fimasartan, candesartan, valsartan, and losartan groups, respectively (P = 0.002). An ALT level > 200 IU/L with RUCAM score ≥ 6 was found in 20 patients, suggesting probable drug-induced liver injury for 11 (0.2%) patients receiving fimasartan, five (0.1%) receiving candesartan, four (0.1%) receiving valsartan, and none receiving losartan (P < 0.001). Conclusion Approximately 2% of patients receiving ARB therapy had significant ALT elevation (4.24/10 6 cumulative defined daily doses [cDDDs]), which was associated with probable ARB-related liver injury in 0.07% of patients (0.15/10 6 cDDDs). Elevation of ALT was more commonly associated with fimasartan than the other ARBs. Clinicians should be aware of the possibility of ARB-related ALT elevation in patients with unexplained chronic abnormal ALT.

Objective: To develop a deep-learning-based bone age prediction model optimized for Korean children and adolescents and evaluate its feasibility by comparing it with a Greulich-Pyle-based deep-learning model. Materials and Methods: A convolutional neural network was trained to predict age according to the bone development shown on a hand radiograph (bone age) using 21036 hand radiographs of Korean children and adolescents without known bone development-affecting diseases/conditions obtained between 1998 and 2019 (median age [interquartile range {IQR}], 9 [7–12] years; male:female, 11794:9242) and their chronological ages as labels (Korean model). We constructed 2 separate external datasets consisting of Korean children and adolescents with healthy bone development (Institution 1: n = 343;median age [IQR], 10 [4–15] years; male: female, 183:160; Institution 2: n = 321; median age [IQR], 9 [5–14] years; male:female, 164:157) to test the model performance. The mean absolute error (MAE), root mean square error (RMSE), and proportions of bone age predictions within 6, 12, 18, and 24 months of the reference age (chronological age) were compared between the Korean model and a commercial model (VUNO Med-BoneAge version 1.1; VUNO) trained with Greulich-Pyle-based age as the label (GP-based model). Results: Compared with the GP-based model, the Korean model showed a lower RMSE (11.2 vs. 13.8 months; P = 0.004) and MAE (8.2 vs. 10.5 months; P = 0.002), a higher proportion of bone age predictions within 18 months of chronological age (88.3% vs. 82.2%; P = 0.031) for Institution 1, and a lower MAE (9.5 vs. 11.0 months; P = 0.022) and higher proportion of bone age predictions within 6 months (44.5% vs. 36.4%; P = 0.044) for Institution 2. Conclusion The Korean model trained using the chronological ages of Korean children and adolescents without known bone development-affecting diseases/conditions as labels performed better in bone age assessment than the GP-based model in the Korean pediatric population. Further validation is required to confirm its accuracy.