Instructor factors associated with medical students' lecture evaluation: a longitudinal analysis.

PURPOSE: This study identified factors that affect lecture evaluation by analyzing sophomores from Dankook University, examining each cluster's characteristics, and comparing differences among trajectories. METHODS: This study identified factors that affect lecture evaluation by analyzing sophomores from Dankook University, examining each cluster's characteristics, and comparing differences among trajectories. RESULTS: The lecture evaluation score decreased as the teaching hours per instructor in a year increased by an hour, and the number of instructors per lecture increased by one individual. During trajectory analysis, the first trajectory had lower lecture evaluation scores overall but relatively high appropriateness of the textbook and punctuality of class, whereas the second trajectory had higher lecture evaluation scores overall for all four items. CONCLUSION: The two trajectories showed differences in teaching methods (understanding of lecture content and usefulness of the lecture) rather than in external factors (appropriateness of the textbook and punctuality of class). Therefore, to improve lecture satisfaction, enhancing instructors' instructional competencies through lectures and adjusting the teaching hours by assigning an adequate number of instructors per lecture are recommended.

Analysis and suggestions on medical educators' roles.

PURPOSE: This study aimed to investigate the differences in the perception between professors and students regarding medical educators' roles and discuss their desirable roles. METHODS: A survey was administered to 116 professors and 379 students of the medical colleges from Dankook University and Hallym University. The subjects were given a self-created questionnaire designed to measure their perception of medical educators' roles. RESULTS: First, "student performance management" for professors and "teaching skill development" for students were recognized as the most essential medical educators' role. Second, females students perceived the roles to be more important than males in eight of 10 roles. CONCLUSION: First, "student performance management" for professors and "teaching skill development" for students were recognized as the most essential medical educators' role. Second, females students perceived the roles to be more important than males in eight of 10 roles.

Perception and attitudes of medical students on clinical clerkship in the era of the Coronavirus Disease 2019 pandemic.

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) has been placing severe strain on global healthcare systems and medical education programs, leading to growing demands for medical students to assume the role of preliminary healthcare providers. OBJECTIVES: To assess the perception and attitudes of medical students about clinical clerkship training during the COVID-19 pandemic. DESIGN: A cross-sectional survey with web-based 3-fields/14-items questionnaire was conducted, from April 7 to 14, 2020, to evaluate their self-assessed perception and attitudes on clerkship training of hospital practice under the COVID-19 outbreak and spread among 161 (78 on pre-clerkship course, 83 on clinical clerkship course) medical students at Dankook University College of Medicine, Cheonan, Republic of Korea. RESULTS: Of the 151 medical students who completed the survey, 81 students (53.7%) considered themselves familiar with COVID-19. Although the students were concerned about the spread of the virus during clinical clerkship training, 118 (78.1%) students preferred the clerkship training in a hospital practice. The students in the clinical clerkship program preferred this over those in the pre-clerkship program (85.7% vs. 70.2%, P = 0.03), primarily because a clinical clerkship could not be replaced by an online class during the COVID-19 pandemic. In addition, their responses indicated, in order of significance, fear of not completing the clerkship course on time, willingness to participate as a preliminary healthcare provider in pandemic, the potential waste of tuition, and belief that a hospital is rather safe. The change in the academic calendar had not a positive impact on the lifestyles of many students. CONCLUSIONS: In circumstances such as the COVID-19 pandemic, educational strategies to clinical clerkship training for medical students should be developed to provide them with the opportunity to be actively involved in hospital practice under strict safety guidance focused on preventing virus infection and transmission.

The relationship between classical item characteristics and item response time on computer-based testing.

PURPOSE: This study investigated the relationship between the item response time (iRT) and classic item analysis indicators obtained from computer-based test (CBT) results and deduce students' problem-solving behavior using the relationship. METHODS: We retrospectively analyzed the results of the Comprehensive Basic Medical Sciences Examination conducted for 5 years by a CBT system in Dankook University College of Medicine. iRT is defined as the time spent to answer the question. The discrimination index and the difficulty level were used to analyze the items using classical test theory (CTT). The relationship of iRT and the CTT were investigated using a correlation analysis. An analysis of variance was performed to identify the difference between iRT and difficulty level. A regression analysis was conducted to examine the effect of the difficulty index and discrimination index on iRT. RESULTS: iRT increases with increasing difficulty index, and iRT tends to decrease with increasing discrimination index. The students' effort is increased when they solve difficult items but reduced when they are confronted with items with a high discrimination. The students' test effort represented by iRT was properly maintained when the items have a 'desirable' difficulty and a 'good' discrimination. CONCLUSION: The results of our study show that an adequate degree of item difficulty and discrimination is required to increase students' motivation. It might be inferred that with the combination of CTT and iRT, we can gain insights about the quality of the examination and test behaviors of the students, which can provide us with more powerful tools to improve them.

Preliminary evaluation of clinical utility of CYFRA 21-1, CA 72-4, NSE, CA19-9 and CEA in stomach cancer.

BACKGROUND: Although various tumor markers have been utilized in management of stomach cancer (SC), only a few reports have described relevance of examples such as CYFRA 21-1 and neuron-specific enolase (NSE). The purpose of this study was to evaluate the potential diagnostic performance of carcinoembryonic antigen (CEA), CA 19-9, CA72-4, CYFRA 21-1 and NSE in patients with SC. MATERIALS AND METHODS: Ninety-six SC patients with pathologic confirmation between 2012 and 2013 were enrolled. Serum levels of five tumor markers were analyzed using a solid-phase immunoradiometric assay. Receiver operating characteristic (ROC) curves were plotted for the five tumor markers to investigate their diagnostic powers and adjusted cutoff values derived from analysis of ROC curves were evaluated to calculate the sensitivity of each for SC with recommended cutoff values. RESULTS: Based on two different cutoff values (recommended and adjusted), CYFRA 21-1 (≥2.0 and 1.2 ng/ml) had a respective sensitivity of 50% and 78.1%, compared with 8.3% and 18.8% for CEA (≥7.0 and 3.9 ng/ml), 15.6% and 18.8% for CA 19-9 (≥37 and 26.7 ng/ml), 28.1% and 9.6% for CA 72-4 (≥4.0 and 13 ng/ml) and 7.3% and 7.3% for NSE (≥14.7 and 15.0 ng/ml) in the initial staging of primary SC. The area under the curve (AUC) for CYFRA 21-1, with a value of 0.978 (95% confidence interval, 0.964-0.991) was comparatively the highest. Univariate analysis revealed significant relationships between tumor marker level and lymph node involvement, metastasis and staging with CYFRA 21-1, CA 72-4 and NSE. CONCLUSIONS: CYFRA 21-1 was the most sensitive tumor marker and showed the most powerful diagnostic performance among the five SC tumor markers. NSE and CA 72-4 are significantly related to lymph node involvement, metastasis or stage. Further evaluations are warranted to clarify the clinical usefulness and prognostic prediction of these markers in SC.

Biologic correlation between glucose transporters, hexokinase-II, Ki-67 and FDG uptake in malignant melanoma.

INTRODUCTION: The purpose of this study was to investigate the correlative association between tumoral 2-deoxy-2-[(18)F]-fluoro-D-glucose (FDG) uptake, and the expressions of glucose transporter 1 (GLUT-1), glucose transporter 3 (GLUT-3), hexokinase II (HK-2), and Ki-67 expression in malignant melanoma. METHODS: Nineteen patients with histologically proven malignant melanoma and pretreatment FDG PET/CT performance were involved in this preliminary study. For semi-quantitative analysis of FDG PET/CT, maximal standardized uptake values (SUVmax) were estimated. Immunohistochemical staining of tumor sections was performed for GLUT-1, GLUT-3, and HK-2, and for the cell proliferation maker Ki-67. Especially, by combining proportions and intensity of immunochemical staining, we evaluated modified immunohistologic scores of GLUT-1 and GLUT-3. RESULTS: The SUVmax of malignant melanoma lesions ranged from 2 to 18.7 (average; 9.1±5.4). Comparison between nodal and extranodal lesions revealed no significant difference of SUVmax (p=0.97). GLUT-1 staining showed the most positive expression level (89.5%, 17/19) among the diverse immunohistochemical markers. There were significant relationships between FDG uptake of malignant melanoma and GLUT-1 proportion (p<0.0001), GLUT-1 intensity (p<0.0001), GLUT-3 proportion (p=0.031), GLUT-3 intensity (p=0.009), GLUT-1 immunohistologic scores (p<0.0001), and GLUT-3 immunohistologic scores (p=0.028). HK-2 was not expressed in all melanoma samples. Although Ki-67 expression showed a high grade in all staining, there was no significant link between FDG uptake and Ki-67 grades (p=0.38). CONCLUSIONS: The data in this preliminary study indicate that FDG uptake in malignant melanoma is determined by GLUT-1 and GLUT-3, whereas HK-2 and Ki-67 play no role in FDG uptake of malignant melanoma.

Urinary metabolites before and after cleanup and subjective symptoms in volunteer participants in cleanup of the Hebei Spirit oil spill.

BACKGROUND: On December 7th, 2007, the Hong Kong tanker Hebei Spirit (HS) (146,848 tons) was crushed by a crane ship near the shore of Taean, Korea. More than 12,547 kl of crude oil spilled into the sea and contaminated the western coastline of the Korean peninsula. For a period of six months after the accident, approximately 1,000,000 volunteers participated in the cleanup. Our goal in this study was to examine the exposure status and acute health effects on volunteers that participated in the oil spill cleanup. METHODS: A survey questionnaire was filled out by 565 volunteers, requesting information regarding physical symptoms. Out of the total number of participants, urine samples from 105 university student volunteers were collected before and after the cleanup work, and metabolite levels of volatile organic compounds and polycyclic aromatic hydrocarbons were analyzed. RESULTS: Volunteers that participated for longer cleanup work reported an increase in physical symptoms including visual disturbance, nasal and bronchus irritation, headaches, heart palpitations, fatigue and fever, memory and cognitive disturbance, and abdominal pain. The levels of t,t-muconic acid, mandelic acid, and 1-hydroxypyrene were significantly higher in samples after cleanup than those measured before participation (p<0.05). Other than the associated risk of dermal irritation with the difference in the t,t-muconic acid level between the post- to pre-cleanup levels, no other physical symptoms demonstrated a significant association with changes observed in the levels of urinary metabolites. CONCLUSIONS: Based on the significant increase of subjective symptoms in volunteers participating in the study, monitoring of the long term health effects, focusing on those with longer exposure, is warranted.

Relationship Between Dual-Time Point FDG PET and Immunohistochemical Parameters in Preoperative Colorectal Cancer: Preliminary Study.

PURPOSE: The clinical availability of 2-deoxy-2-[18F] fluoro-D-glucose (FDG) dual-time point positron emission tomography/computerized tomography (DTPP) has been investigated in diverse oncologic fields. The aim of this preliminary study was to evaluate the relationship between various immunohistopathologic markers reflecting disease progression of colorectal cancer and parameters extracted from FDG DTPP in colorectal cancer patients. MATERIALS AND METHODS: Forty-seven patients with histologically confirmed colorectal cancer were analyzed in this preliminary study. FDG DTPP consisted of an early scan 1 h after FDG injection and a delayed scan 1.5 h after the early scan. Based on an analysis of FDG DTPP, we estimated the maximum standardized uptake value (SUV) of tumors on the early and delayed scans (SUVearly and SUVdelayed, respectively). The retention index (RI) was calculated as follows: (SUVdelayed - SUVearly) × 100/ SUVearly. The clinicopathological findings (size and T and N stages) and immunohistochemical factors [glucose transporter 1 (GLUT-1), hexokinase 2 (HK-2), p53, P504S, and ß-catenin] were analyzed by visual analysis. RESULTS: The RIs calculated from the SUVs ranged from -1.8 to 73.4 (31.8 ± 15.5). The RIs were significantly higher in patients with high T stages (T3 and T4) than with low T stages (T1 and T2; p < 0.05). Among the immunohistochemical analytic markers, GLUT-1 had the highest positive staining rate (93.6%) compared to other markers. Based on univariable analysis, it was shown that the RI of high-level GLUT-1 expression was significantly higher than low-level GLUT-1 expression (p = 0.01), and the RI of high-level p53 expression was slightly higher than low-level p53 expression (p = 0.08). Multivariate analysis to investigate a link between RI and clinicopathologic parameters of colorectal carcinoma showed that GLUT-1, p53, and T staging were independently connected with increased RIs (p < 0.05, total) using backward selection methods. There was no significant statistical relationship between SUVearly and SUVdelayed and clinicopathologic parameters in this study. CONCLUSION: The RIs obtained from preoperative colorectal cancers had a significant relationship to tumor size, T staging, GLUT-1, and p53, in contrast to SUVearly or SUVdelayed. Compared with previous reports, our results showed that RI can better predict GLUT-1 expression than HK-2 and other immunohistochemical markers. This study demonstrated that the RI might have the potential to be applied as a prognostic marker in preoperative colorectal cancer.

F-18 FDG PET/CT imaging of solitary genital tuberculosis mimicking recurrent lymphoma.

A 65-year-old man who had multiple lymph nodes swelling was pathologically diagnosed with diffuse large B cell lymphoma. After initiation of induction chemotherapy, F-18 FDG PET/CT showed a significantly decreased extent of previous lymphomatous lesions except for 2 newly developed focal hypermetabolic lesions in the prostate and left epididymis. The specimens from the prostate and orchiectomy revealed tuberculosis lesions. After a 3-month antituberculosis regimen, there was definitively decreased glucose uptake in the prostate on F-18 FDG PET. F-18 FDG PET may be helpful for characterizing genitourinary tuberculosis and monitoring antituberculosis treatment.

Performance of FDG PET/CT in postoperative colorectal cancer patients with a suspected recurrence and a normal CEA level.

PURPOSE: The performance of 2-deoxy-2-[(18)F]fluoro-D-glucose positron emission tomography/computed tomography (FDG PET/CT) has been not established for the evaluation of recurrent colorectal cancer. The aim of this study was to evaluate the diagnostic value of FDG PET/CT in postoperative colorectal cancer patients with normal carcinoembryonic antigen (CEA) levels. METHODS: This retrospective study was conducted on 63 FDG PET/CT cases, involving postoperative colorectal cancer patients suspected of having recurrent or metastatic lesions with normal CEA levels. The diagnostic performance of FDG PET/CT was evaluated based on diverse suspected conditions, using physical examination, a conventional imaging work-up, and endoscopy. Histopathology, a clinical imaging work-up (including an FDG PET/CT examination), and determination of tumor marker levels during the follow-up served as the reference standard. RESULTS: The sensitivity, specificity, and accuracy for FDG PET/CT were 95, 76.6, and 88.8% for a lesion-by-lesion analysis, and 96.3, 86.1, and 90.5% for a case-by-case analysis, respectively. Three false-negative lesions among 107 suspected recurrent findings were identified as compared with nine false-positive lesions. For radiologically suspected recurrent or metastatic conditions, FDG PET/CT diagnostic performance was superior to radiological image modalities, for both lesion-by-lesion and case-by-case analyses. On follow-up of patients with normal CEA levels, but high CA19-9 levels, the use of FDG PET/CT detected true-positive findings in 63.3% of cases. CONCLUSION: FDG PET/CT is a valuable tool to distinguish recurrence or metachronous tumor from postoperative changes or other benign lesions in postoperative colorectal cancer patients with normal CEA levels and radiologically or clinically suspicious lesions.

Estimation of the Release Time from Isolation for Patients with Differentiated Thyroid Cancer Treated with High-dose I-131.

PURPOSE: Patients receiving high-dose I-131 to treat differentiated thyroid cancer are isolated from visitors to limit radiation exposure to reasonable levels. The appropriate isolation time is unclear and has not been reported in Korea. The purpose of this study was to estimate the isolation time and investigate the possibility of earlier release from isolation. METHODS: This study was a retrospective analysis of data from 71 patients (10 men and 61 women; mean age, 49 ± 11.1 y) who received 3.7 GBq (47 patients), 5.55 GBq (23 patients), or 7.4 GBq (1 patient) of I-131 between January 2008 and December 2008. The radiation dose was measured with a fixed probe placed inside the isolation room. The total estimated dose equivalent (TEDE) to family members, the time required for the external dose rate to become <0.07 mSv/h, and the time required for whole-body retention to become <1.2 GBq were calculated. RESULTS: By the TEDE criterion (<5 mSv), 70 of 71 patients (98.6%) could have been released without isolation. By the external dose rate criterion, 10 of 71 (14.1%) and 60 of 71 patients (84.5%) could have been released without isolation and within 24 h, respectively. With whole-body retention criterion, 19 of 71 (26.8%) and 48 of 71 patients (67.6%) could have been released within 24 h and within 48 h, respectively. CONCLUSIONS: Appropriate release times were estimated and compared using different criteria. Most patients could have been released without isolation or within 24 h of radiation treatment.

The diagnosis and prognosis of impingement syndrome in the shoulder with using quantitative SPECT assessment: a prospective study of 73 patients and 24 volunteers.

BACKGROUND: Diagnosing impingement syndrome without rotator cuff tear usually depends on the physical examination and roentgenography, and obtaining objective evidence for this condition is at best difficult. The purpose of this study was to ascertain whether quantitatively assessing this condition with using single photon emission computerized tomography (SPECT) can diagnose impingement syndrome and predict the postoperative results. METHODS: Before executing arthroscopic or open treatment, SPECT was performed on 73 patients and 24 volunteers and these people were followed up for 2 years. Any increased uptake on SPECT was investigated by using the axial view, which demonstrated the greatest uptake for the acromion, distal clavicle, greater tuberosity, lesser tuberosity and the coracoid process of the operated and non-operated sides. RESULTS: The patients who were diagnosed as having impingement syndrome with or without rotator cuff tear showed increased uptake on the operative side compared to the non-operated side in the assessed locations. The greater tuberosity of the humerus could be used for quantitative measurement as a postoperative prognostic factor. CONCLUSIONS: The bone SPECT method is useful for making the diagnosis of patients with impingement syndrome, and the results of quantitative assessment at the greater tuberosity can be used for evaluating the prognosis following the operation.

[The effects of wearing protective devices among residents and volunteers participating in the cleanup of the Hebei Spirit oil spill].

OBJECTIVES: To assess the protective effects of wearing protective devices among the residents and volunteers who participated in the cleanup of the Hebei Spirit oil spill. METHODS: A total of 288 residents and 724 volunteers were surveyed about symptoms, whether they were wearing protective devices and potential confounding variables. The questionnaires were administered from the second to the sixth week following the accident. Spot urine samples were collected and analyzed for metabolites of 4 volatile organic compounds (VOCs), 2 polycyclic aromatic hydrocarbons (PAHs), and 6 heavy metals. The association between the wearing of protective devices and various symptoms was assessed using a multiple logistic regression adjusted for confounding variables. A multiple generalized linear regression model adjusted for the covariates was used to test for a difference in least-square mean concentration of urinary biomarkers between residents who wore protective devices and those who did not. RESULTS: Thirty nine to 98% of the residents and 62-98% of volunteers wore protective devices. Levels of fatigue and fever were higher among residents not wearing masks than among those who did wear masks (odds ratio 4.5; 95% confidence interval 1.23-19.86). Urinary mercury levels were found to be significantly higher among residents not wearing work clothes or boots (p<0.05). CONCLUSIONS: Because the survey was not performed during the initial high-exposure period, no significant difference was found in metabolite levels between people who wore protective devices and those who did not, except for mercury, whose biological half-life is more than 6 weeks.

Struma ovarii and peritoneal strumosis with thyrotoxicosis.

BACKGROUND: Struma ovarii is a highly specialized form of mature ovarian teratoma consisting of thyroid tissue and exhibiting all the histological features of the thyroid gland. Malignant transformation of thyroid tissue in struma ovarii and metastasis are extremely uncommon. In rare cases, benign thyroid tissue may spread to the peritoneal cavity, and pathologic examination of the peritoneal implants shows multiple nodules of varying sizes of mature thyroid tissue similar to struma ovarii. This condition is termed "peritoneal strumosis." SUMMARY: We report a 49-year-old woman with struma ovarii complicated by peritoneal strumosis with thyrotoxicosis. After surgical resection of the struma ovarii and peritoneal strumosis the patient became euthyroid. CONCLUSION: To the best of our knowledge this is the first report of a patient with peritoneal strumosis complicated by thyrotoxicosis. The relative contribution to circulating thyroid hormones by the patient's struma ovarii as compared to the peritoneal strumosis is not known.

Differences between Scores Assessed by Examiners and Examinees on Objective Structured Clinical Examination.

PURPOSE: Self-assessment is important for learning. But, the reliability of self-assessment has long been questioned. We investigated this problem in an objective structured clinical examination (OSCE) setting. METHODS: Forty third-year nursing students who participated in the OSCE were given the same checklist that was used for assessment by the examiners after they finished the OSCE. Then, the scores that were calculated by the examiners and examinees were compared, measuring the average, correlation, difference in score between examinee and examiner, difference in score according to the examinee's level, and Z-score. RESULTS: Scores that were made by the examinees were significantly higher than those of the examiners (average 72.34 vs. 64.03), between which there was a loose positive correlation (r=0.34). The correlation coefficient increased (r=0.62) when a difference in score (examinee-examiner) was compared with the examiner score. When examinees were divided into 3 groups according to their scores, the difference tended to become less as the scores of examinee rose. When the Z-score was compared with the level of the examinee, examinees who had higher scores evaluated themselves lower than the examiners, and examinees with lower scores assessed themselves higher than the examiners. CONCLUSION: According to comparison of averages or correlation analysis, self-assessment by the examinee appeared to be less reliable. But when data were analyzed using difference in score, examinee levels, and Z-score, a certain tendency developed. This pattern may be due to the heterogeneity of the examinee group. Selection of appropriate analysis methods might be important to estabilish the reliability of self-assessment skills.

Quantitative evaluation of very acute stage of complex regional pain syndrome after stroke using three-phase bone scintigraphy.

PURPOSE: Three-phase bone scintigraphy (TPBS) is an objective diagnostic test for complex regional pain syndrome (CRPS). The diagnostic importance of an increased uptake on the delayed phase has been proven in early CRPS, but that of the vascular and blood pool phases has not. The purpose of this study is to improve the diagnostic strength of the very acute stage of CRPS after stroke through a combined quantitative evaluation of each TPBS phase. METHODS: Quantitative TPBS analysis was performed in 26 post-stroke hemiplegic patients with very acute stage of CRPS and in 12 controls with no CRPS after brain lesion. Regions of interest (hands without fingers--carpal bones, metacarpal bones and metacarpopharyngeal joints) were selected and the count ratios of the affected to unaffected sides were calculated. RESULTS: The maximum values of control in each phase were used as the criteria of positive findings of each TPBS phase. Eleven patients in the vascular phase, 13 in the blood pool phase and 17 in the delayed phase had a higher assumption than the maximum values and a sensitivity of 42.3%, 50% and 65.4%, respectively. Twenty-one of 26 patients were interpreted as abnormal when at least one phase showed a positive finding. As a result, increased sensitivity of 80.8% and identical specificity of 100% were achieved. CONCLUSION: These findings suggest that the combination of quantitative evaluation of each TPBS phase can improve the diagnostic strength of the very acute stage of CRPS after stroke.