807 research outputs found
Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma: Prevalence and Causative Factors of Extrahepatic Collateral Arteries in 479 Patients
OBJECTIVE: We wanted to investigate the prevalence and causative factors of extrahepatic arterial blood supply to hepatocellular carcinoma (HCC) at its initial presentation and during chemoembolization. MATERIALS AND METHODS: Between February 1998 and April 2000, consecutive 479 patients with newly diagnosed HCC were prospectively enrolled into this study. A total of 1629 sessions of transcatheter arterial chemoembolization (TACE) were performed in these patients (range: 1-15 sessions; mean: 3.4 sessions) until April 2004. For each TACE procedure, we determined the potential extrahepatic collateral arteries (ExCAs) depending on the location of the tumor, and we performed selective angiography of all suspected collaterals that could supply the tumor. The prevalence of ExCAs and the causative factors were analyzed. RESULTS: At initial presentation, 82 (17%) of these 479 patients showed 108 ExCAs supplying tumors. Univariate analysis showed that tumor size (p or =5 cm) was significantly higher than that for those patients with a small tumor (< 5 cm) (p < 0.01). CONCLUSION: The presence of ExCAs supplying HCC is rather common, and the tumor size is a significant causative factor for the development of these collateral arteries.This study was supported by a grant
(0620220-1) from the National R & D
Program for Cancer Control, Ministry of
Health & Welfare, Republic of Korea
Determination of Cutting Date and Interval on Native Grass Management of Agricultural Waterways in South Korea
Agricultural waterways provide a buffer zone between crop fields and adjacent rivers or streams. Waterways are important resource for agriculture water management, water quality and biodiversity conservation. The total linear distance of waterway in Korea is about 180,000 km, and about 40% are concrete and about 60% are grassed waterways. At present, the percentage of concrete waterways is increasing because of their water management efficiency. Some argue that continued expansion of concrete waterways is not sustainable because it leads to potential-degradation of the earth\u27s environment. This concern has led to renewed efforts to use grassed waterways as an alternative to concrete. In addition, grassed waterways enhance the environment-friendly image of agriculture that Korea farmers want to promote. The objective of this experiment was to determine the effect of cutting date and interval of native grasses for water management efficiency of agricultural waterway
Passivity, task segmentation, and relational capital: a study of interpersonal relationship formation among freshman medical students in team-based activities
Purpose Team-based learning in medical education facilitates the formation of interpersonal relationships, enhances academic achievement, and establishes future clinical connections. Despite medical schools’ distinct educational environments and curricula, research investigating students’ learning and behavioral characteristics within this context remains limited. This study aimed to investigate the specific characteristics of interpersonal relationship formation among freshmen medical students in team-based learning activities. Methods Focus group interviews were conducted with 11 students who participated in a team-based class held during the first semester of the premedical year. Results Medical students passively expressed their thoughts and feelings, such as active sympathy for the team’s opinions and self-censorship of SNS (social networking service) conversations. When performing team activities, students were excessively conscious of others and focused on evenly dividing their work, minimizing their opinions, and fulfilling their share to prevent potential interpersonal conflicts. Interpersonal activities were only superficial, as students intentionally maintained a certain distance from team members or used team activities as an opportunity to accumulate relational capital. Conclusion The results of this study are expected to provide a useful basis for designing and conducting team activity classes to enhance interpersonal relationship formation
Arabidopsis U2AF65 Regulates Flowering Time and the Growth of Pollen Tubes
During pre-mRNA splicing, U2 small nuclear ribonucleoprotein auxiliary factor 65 (U2AF65) interacts with U2AF35 and splicing factor 1 (SF1), allowing for the recognition of the 3′-splice site by the ternary complex. The functional characterization of U2AF65 homologs has not been performed in Arabidopsis thaliana yet. Here, we show that normal plant development, including floral transition, and male gametophyte development, requires two Arabidopsis U2AF65 isoforms (AtU2AF65a and AtU2AF65b). Loss-of-function mutants of these two isoforms displayed opposite flowering phenotypes: atu2af65a mutants showed late flowering, whereas atu2af65b mutants were characterized by slightly early flowering, as compared to that in the wild-type (Col-0) plants. These abnormal flowering phenotypes were well-correlated with the expression patterns of the flowering time genes such as FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT). However, the two atu2af65 mutants did not display any morphological abnormalities or alterations in abiotic stress tests. Double mutation of the AtU2AF65a and AtU2AF65b genes resulted in non-viable seeds due to defective male gametophyte. In vitro pollen germination test revealed that mutations in both AtU2AF65a and AtU2AF65b genes significantly impaired pollen tube growth. Collectively, our findings suggest that two protein isoforms of AtU2AF65 are differentially involved in regulating flowering time and display a redundant role in pollen tube growth
Potentiated therapeutic angiogenesis by primed human mesenchymal stem cells in a mouse model of hindlimb ischemia
Background: Human bone marrow-derived mesenchymal stem cells (hMSCs) are advantageous for cell-based therapy to treat ischemic diseases owing to their capacity to secrete various paracrine factors with potent angiogenic activity. Materials methods: In this study, we describe a method to increase secreted levels of VEGF and HGF from hMSCs without genetic modification. Results: We demonstrated that transplantation of primed hMSCs into ischemic limbs led to significantly greater improvements in tissue perfusion and limb salvage by increasing capillary formation compared with nonprimed hMSCs. The primed hMSCs also exhibited greater survival in vivo and secreted human VEGF and HGF in the ischemic tissue, supporting enhanced angiogenesis and cell survival. Conclusion: These findings indicate that priming hMSCs via methods described in this study enhances secretion of critical proangiogenic factors resulting in an enhanced therapeutic effect of cells for the treatment of ischemic diseases.This research was supported by grants from the Korea Health Technology R&D Project (M-S Chang, A100823) and the Innovative Research Institute for Cell Therapy, National University Hospital (A062260), both sponsored by the Ministry of Health, Welfare and Family, Seoul, Republic of Korea.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000027724/1SEQ:1PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000027724ADJUST_YN:YEMP_ID:A075930DEPT_CD:862CITE_RATE:3.718FILENAME:첨부된 내역이 없습니다.DEPT_NM:치의과학과EMAIL:[email protected]_YN:YCONFIRM:
Changes in academic performance in the online, integrated system-based curriculum implemented due to the COVID-19 pandemic in a medical school in Korea
Purpose This study examined how students’ academic performance changed after undergoing a transition to online learning during the coronavirus disease 2019 (COVID-19) pandemic, based on the test results of 16 integrated courses conducted in 3 semesters at Hanyang University College of Medicine in Korea. Methods For the 16 required courses that formed an integrated system-based curriculum running for 3 semesters, the major examinations’ raw scores were collected for each student. Percent-correct scores were used in the subsequent analysis. We used the t-test to compare grades between 2019 and 2020, and the Cohen D was calculated as a measure of effect size. The correlation of scores between courses was calculated using Pearson correlation coefficients. Results There was a significant decrease in scores in 2020 for 10 courses (62.5%). While most of the integrated system-based curriculum test scores showed strong correlations, with coefficients of 0.6 or higher in both 2019 and 2020, the correlation coefficients were generally higher in 2020. When students were divided into low, middle, and high achievement groups, low-achieving students consistently showed declining test scores in all 3 semesters. Conclusion Our findings suggest that the transition to online classes due to COVID-19 has led to an overall decline in academic performance. This overall decline, which may occur when the curriculum is centered on recorded lectures, needs to be addressed. Further, medical schools need to consider establishing a support system for the academic development of low-achieving students
Importance of remission and residual somatic symptoms in health-related quality of life among outpatients with major depressive disorder: a cross-sectional study
Background: Major depressive disorder (MDD) is strongly associated with an impaired quality of life (QoL), which is itself affected by various factors. Symptom-oriented ratings poorly reflect the impact of disease on the QoL and level of functioning of the mental health of subjects. The purpose of this study was to assess health-related QoL (HRQoL) using preference-based measures in outpatients with MDD with regard to their remission achievement and clinical factors affecting the HRQoL. Methods: This was a cross-sectional observational study. We recruited 811 patients with MDD from 14 psychiatric outpatient clinics in Korea. They were divided into three groups as follows: a new visit group (n = 287), a remitted group (n = 235), and a non-remitted group (n = 289). The 17-item Hamilton Depression Rating Scale was used to assign patients to the remitted or non-remitted group. The general HRQoL was assessed with the EuroQol 5D (EQ-5D), using both the EQ-5D index score and the EuroQol Visual Analog Scale (EQ-VAS). The disease-specific HRQoL was assessed with the Quality of Life Enjoyment and Satisfaction Questionnaire Short Form (Q-LES-Q-SF). Results: The non-remitted group showed a significant impairment of HRQoL in view of the subscales of EQ-5D index scores, EQ-VAS, and Q-LES-Q-SF. The EQ-5D index score in the remitted group was 0.77 ± 0.10, while it was 0.57 ± 0.23 in the non-remitted group and 0.58 ± 0.24 in the new visit group (p < 0.0001). The EQ-VAS scores for the remitted and non-remitted groups were 72.5 ± 16.6 and 50.9 ± 20.3, respectively (p < 0.0001). Likewise, patients with remission had the Q-LES-Q-SF total score of 46.5 ± 8.8, whereas those with non-remission reported 36.7 ± 7.7 (p < 0.0001). The symptom severity measured by the Depression and Somatic Symptoms Scale was significantly correlated with the HRQoL. Furthermore, patients with severe somatic symptoms showed a significantly lower EQ-5D index score (0.54 ± 0.24) than those with mild/moderate somatic symptoms (0.75 ± 0.12; p = 0.002). Conclusion: Non-remitted MDD patients, especially those with more severe somatic symptoms, show a distinct impairment of HRQoL and more clinical symptoms, suggesting the importance of achieving remission in the treatment of MDD
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