Young Hwan Lee

Subungual Tumors: Clinicopathologic Correlation with US and MR Imaging Findings

Various types of tumors can affect the subungual space, including benign solid tumors (glomus tumor, subungual exostosis, soft-tissue chondroma, keratoacanthoma, hemangioma, lobular capillary hemangioma), benign cystic lesions (epidermal and mucoid cysts), and malignant tumors (squamous cell carcinoma, malignant melanoma). Imaging plays an important role in the detection and differentiation of subungual tumors because of their small size, nonspecific clinical manifestations, and functional significance. Ultrasonography (US)-in particular, high-resolution US with color Doppler studies-provides useful information regarding tumor size, location, shape, and internal characteristics (cystic, solid, or mixed), but it is limited in the further characterization of tissue. Magnetic resonance (MR) imaging has an important role in categorizing tumors according to their anatomic location, pathologic origin, and signal characteristics. There is some overlap between the US and MR imaging features of subungual tumors; however, certain features can allow accurate diagnosis and expedite management when correlated with clinical and pathologic findings.

A Fatal Case of Severe Hemolytic Disease of Newborn Associated with Anti-Jkb

The Kidd blood group is clinically significant since the Jk antibodies can cause acute and delayed transfusion reactions as well as hemolytic disease of newborn (HDN). In general, HDN due to anti-Jkb incompatibility is rare and it usually displays mild clinical symptoms with a favorable prognosis. Yet, we apparently experienced the second case of HDN due to anti-Jkb with severe clinical symptoms and a fatal outcome. A female patient having the AB, Rh(D)-positive boodtype was admitted for jaundice on the fourth day after birth. At the time of admission, the patient was lethargic and exhibited high pitched crying. The laboratory data indicated a hemoglobin value of 11.4 mg/dL, a reticulocyte count of 14.9% and a total bilirubin of 46.1 mg/dL, a direct bilirubin of 1.1 mg/dL and a strong positive result (+++) on the direct Coombs test. As a result of the identification of irregular antibody from the maternal serum, anti-Jkb was detected, which was also found in the eluate made from infants blood. Despite the aggressive treatment with exchange transfusion and intensive phototherapy, the patient died of intractable seizure and acute renal failure on the fourth day of admission. Therefore, pediatricians should be aware of the clinical courses of hemolytic jaundice due to anti-Jkb, and they should be ready to treat this disease with active therapeutic interventions.

Stress and Heart Rate Variability: A Meta-Analysis and Review of the Literature

Objective Physical or mental imbalance caused by harmful stimuli can induce stress to maintain homeostasis. During chronic stress, the sympathetic nervous system is hyperactivated, causing physical, psychological, and behavioral abnormalities. At present, there is no accepted standard for stress evaluation. This review aimed to survey studies providing a rationale for selecting heart rate variability (HRV) as a psychological stress indicator. Methods Term searches in the Web of Science®, National Library of Medicine (PubMed), and Google Scholar databases yielded 37 publications meeting our criteria. The inclusion criteria were involvement of human participants, HRV as an objective psychological stress measure, and measured HRV reactivity. Results In most studies, HRV variables changed in response to stress induced by various methods. The most frequently reported factor associated with variation in HRV variables was low parasympathetic activity, which is characterized by a decrease in the high-frequency band and an increase in the low-frequency band. Neuroimaging studies suggested that HRV may be linked to cortical regions (e.g., the ventromedial prefrontal cortex) that are involved in stressful situation appraisal. Conclusion In conclusion, the current neurobiological evidence suggests that HRV is impacted by stress and supports its use for the objective assessment of psychological health and stress.

Production of Chemokines in Kawasaki Disease, Henoch-Schönlein Purpura and Acute Febrile Illness

We compared the production of three chemokines; interferon-γ-inducible protein-10 (IP-10), monocyte chemoattractant protein-1 (MCP-1) and growth-related oncogene-α (Gro-α) that attracts monocytes or neutrophils, or both, in peripheral blood at acute stage of Kawasaki disease (n=29), Henoch-Schönlein purpura (n=15) and acute febrile illnesses (n=12). The production of the chemokines was assayed by ELISA. The plasma levels of IP-10 were markedly elevated in Kawasaki disease (538.6±336.4 pg/mL) and acute febrile illnesses (417.1±262.2 pg/mL) compared with in Henoch-Schönlein purpura (58.7±95.7 pg/mL) (p<0.05). The MCP-1 levels were elevated in Kawasaki disease (443.0±473.1 pg/mL) and acute febrile illnesses (328.6±261.1 pg/mL) compared with in Henoch-Schönlein purpura (82.9±79.0 pg/mL) (p<0.05). The Gro-α levels were elevated only in acute febrile illnesses (134.3±153.6 pg/mL) compared with in Kawasaki disease (31.8±22.1 pg/mL) or Henoch-Schönlein purpura (29.4±53.3 pg/mL) (p<0.05). According to these results, monocytes may play an important role in Kawasaki disease. In acute febrile illnesses, both monocytes and neutrophils may play an important role. By contrast, Henoch-Schönlein purpura may not be associated with the role of monocytes and neutrophils. Further studies using a larger number of cases are needed.

Candidate tumor suppressor, HCCS‐1, is downregulated in human cancers and induces apoptosis in cervical cancer

To identify the genes involved in cervical carcinogenesis, we applied the mRNA differential display method and identified a candidate tumor suppressor gene, HCCS‐1, which was present in normal cervical tissue but absent in cervical cancer, metastatic lymph node and CUMC‐6 cervical cancer cell line. HCCS‐1 transcripts were expressed in many normal tissues including leukocyte, lung, spleen, liver, heart and uterine cervix. Its expression was absent in 8 human cancer cell lines. HCCS‐1‐transfected HeLa cells exhibited growth inhibition by about 50%. This inhibitory effect of HCCS‐1 on cervical cancer cells was associated with apoptotic process including DNA fragmentation. HCCS‐1‐transfected HeLa cells were shown to release cytochrome c from mitochondria, which activates caspase‐9 and ‐3 and finally results in cleavage of poly(ADP‐ribose) polymerase. Apoptosis formation was detected by propidium‐iodide/annexin V. HCCS‐1‐transfected HeLa cells were more sensitive to adriamycin or UVC ray triggered apoptosis. These results suggest that HCCS‐1 is downregulated in multiple human tumor types and may serve as a candidate tumor suppressor gene through apoptotic pathway against human cervical cancer.

Clinical characteristics of Kawasaki disease with sterile pyuria

Purpose Kawasaki disease (KD) is a systemic vasculitis and affects many organ systems. It often presents sterile pyuria, microscopic hematuria, and proteinuria due to renal involvement. The aims of this study were to define clinical characteristics of acute KD patients with pyuria and to analyze meaning of pyuria in KD. Methods The medical records and laboratory findings including serum and urine test of 133 patients with KD admitted to Yeungnam University Hospital from March 2006 to December 2010 were reviewed retrospectively. Results Forty patients had sterile pyuria and their clinical characteristics including age, gender and body weight were not significantly different with those who did not have pyuria. Fever duration after treatment was significantly longer in KD patients with pyuria. Erythrocyte sedimentation rate, C-reactive protein and serum concentration of alanine aminotransferase were significantly higher in patients with pyuria. Hyponatremia and coronary artery lesion were seen more often in patients with pyuria but there was no significant difference. Also serum blood urea nitrogen was significantly higher in KD patients with pyuria. Urine β2-microglobulin was elevated in both patients groups and showed no difference between two groups. Conclusion We found more severe inflammatory reaction in KD patients with pyuria. We also found elevation of some useful parameters like β2-microglobulin that indicate renal involvement of KD through the urine test. Careful management and follow up will need for KD patients with pyuria and it is necessary in the future to study the specific parameters for renal involvement of KD.

Kikuchi-Fujimoto disease mimicking malignant lymphoma with 2-[(18)F]fluoro-2-deoxy-D-glucose PET/CT in children.

Purpose Kikuchi-Fujimoto disease (KFD) is a benign disease, which is characterized by a cervical lymphadenopathy with fever, and it often mimics malignant lymphoma (ML). 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) is a powerful imaging modality for the diagnosis, staging and monitoring of ML, with the limitations including the nonspecific FDG uptake in infectious or inflammatory processes. This study compared clinical manifestations and PET/CT findings between KFD and ML patients. Methods We retrospectively reviewed the medical records of 23 patients with KFD and 33 patients with ML, diagnosed histopathologically, between January 2000 and May 2013 at the Department of Pediatrics, Yeungnam University Medical Center. Among them, we analyzed the clinical manifestations, laboratory findings and characteristics, and the amount of 18F-FDG uptake between 8 KFD and 9 ML patients who had 18F-FDG PET/CT. Results The 18F-FDG PET/CT maximum standardized uptake values (SUVmax) ranged from 8.3 to 22.5 (mean, 12.0) in KFDs, and from 5.8 to 34.3 (mean, 15.9) in MLs. There were no significant differences in SUVmax between KFDs and MLs. 18F-FDG PET/CT with ML patients showed hot uptakes in the extranodal organs, such as bone marrow, small bowel, thymus, kidney, orbit and pleura. However, none of the KFD cases showed extranodal uptake (P<0.001). 18F-FDG PET/CT findings of KFD with nodal involvement only were indistinguishable from those of ML. Conclusion Patients who had extranodal involvement on PET/CT were more likely to have malignancy than KFD.

Academic burnout and selection-optimization-compensation strategy in medical students

PURPOSE This study was conducted to examine the relationship between academic demand, academic burnout, and the selection-optimization-compensation (SOC) strategy in medical students. METHODS A total of 317 students at Yeungnam University, comprising 90 premedical course students, 114 medical course students, and 113 graduate course students, completed a survey that addressed the factors of academic burnout and the selection-optimization-compensation strategy. We analyzed variances of burnout and SOC strategy use by group, and stepwise multiple regression analysis was conducted. RESULTS There were significant differences in emotional exhaustion and cynicism between groups and year in school. In the SOC strategy, there were no significant differences between groups except for elective selection. The second-year medical and graduate students experienced significantly greater exhaustion (p<0.001), and first-year premedical students experienced significantly higher cynicism (p<0.001). By multiple regression analysis, subfactors of academic burnout and emotional exhaustion were significantly affected by academic demand (p<0.001), and 46% of the variance was explained. Cynicism was significantly affected by elective selection (p<0.05), and inefficacy was significantly influenced by optimization (p<0.001). CONCLUSION To improve adaptation, prescriptive strategies and preventive support should be implemented with regard to academic burnout in medical school. Longitudinal and qualitative studies on burnout must be conducted.

T-Helper Cytokine Profiles in Patients with Kawasaki Disease.

Background and Objectives Kawasaki disease is an acute systemic vasculitis of which pathogenesis suspected is caused by immune dysregulation. The goal of this study is to evaluate the activation pattern of T helper cell type 1 (Th1) and T helper cell type 2 (Th2) in patients with Kawasaki disease. Subjects and Methods Prospective study of 60 patients (male 36, female 24) with diagnosis of Kawasaki disease were enrolled. One hundred and eighty blood samples from these patients were collected according to the different clinical stages {before initial intravenous immunoglobulin (IVIG), 5 days after initial IVIG, 2 months after initial IVIG}. The plasma level of Th1 cytokines; interferon-gamma (IFN-γ) & interleukin (IL)-2 and Th2 cytokines; IL-4 & IL-10 were measured by enzyme-liked immunosorbent assay. Results In all patients, the plasma level of Th1 cytokines (IFN-γ, IL-2) and Th2 cytokines (IL-4 and IL-10) were markedly elevated during the acute stage of Kawasaki disease. Since then, the plasma level of all these cytokines decreased significantly along with the process of clinical stages. Regardless of the existence of coronary artery lesion or no response to initial IVIG treatment, there were no significant differences between them. Conclusion These data suggest that both Th1 and Th2 cells may be activated simultaneously during the acute stage of Kawasaki disease. Further studies are therefore required to establish the difference of activation pattern of T helper cells between Kawasaki disease and other inflammatory diseases.

Improvement of debate competence: an outcome of an introductory course for medical humanities

Purpose: Academic debate is an effective method to enhance the competences of critical thinking, problem solving, communication skills and cooperation skills. The present study examined the improvement of debate competence which is an outcome of debate-based flipped learning. Methods: A questionnaire was administrated to second-year premedical school students at Yeungnam University. In total 45 students participated in the survey. The survey questionnaire was composed of 60 items of eight subfactors on debate competence. To investigate the homogeneous of low and high achievement groups, 18 items on empathy and 75 items on critical thinking scales were used. To compare the pretest with posttest scores, data was analyzed using paired sample t-test. Results: There were no significant differences between low and high achievement groups by average grade at the beginning of the semester. There was a significant improvement in high achievers on the logical argumentation (p<0.001), proficiency in inquiry (p<0.01), active participation (p<0.001), ability to investigate and analyze (p<0.001), observance of debate rules (p<0.05), and acceptability (p<0.05). Even in low achievers, active participation (p<0.05) and ability to investigate and analyze (p<0.01) were significantly improved. Conclusion: Results showed that students could improve their debate competence by the debate-based flipped learning. A prospective and comparative study on the communication and teamwork competences needs to be conducted in the future. It is suggested that in-depth discussion for the curriculum design and teaching will be needed in terms of the effectiveness and the outcomes of the medical humanities.