1.The Differential Developmental Neurotoxicity of Valproic Acid on Anterior and Posterior Neural Induction of Human Pluripotent Stem Cells
Jeongah KIM ; Si-Hyung PARK ; Woong SUN
International Journal of Stem Cells 2025;18(1):49-58
Valproic acid (VPA), widely used as an antiepileptic drug, exhibits developmental neurotoxicity when exposure occurs during early or late pregnancy, resulting in various conditions ranging from neural tube defects to autism spectrum disorders. However, toxicity during the very early stages of neural development has not been addressed. Therefore, we investigated the effects of VPA in a model where human pluripotent stem cells differentiate into anterior or posterior neural tissues. Exposure to VPA during the induction of neural stem cells induced different developmental toxic effects in a dose-dependent manner. For instance, VPA induced cell death more profoundly during anteriorly guided neural progenitor induction, while inhibition of cell proliferation and enhanced differentiation were observed during posteriorly guided neural induction. Furthermore, acute exposure to VPA during the posterior induction step also retarded the subsequent neurulation-like tube morphogenesis process in neural organoid culture. These results suggest that VPA exposure during very early embryonic development might exhibit cytotoxicity and subsequently disrupt neural differentiation and morphogenesis processes.
2.The Differential Developmental Neurotoxicity of Valproic Acid on Anterior and Posterior Neural Induction of Human Pluripotent Stem Cells
Jeongah KIM ; Si-Hyung PARK ; Woong SUN
International Journal of Stem Cells 2025;18(1):49-58
Valproic acid (VPA), widely used as an antiepileptic drug, exhibits developmental neurotoxicity when exposure occurs during early or late pregnancy, resulting in various conditions ranging from neural tube defects to autism spectrum disorders. However, toxicity during the very early stages of neural development has not been addressed. Therefore, we investigated the effects of VPA in a model where human pluripotent stem cells differentiate into anterior or posterior neural tissues. Exposure to VPA during the induction of neural stem cells induced different developmental toxic effects in a dose-dependent manner. For instance, VPA induced cell death more profoundly during anteriorly guided neural progenitor induction, while inhibition of cell proliferation and enhanced differentiation were observed during posteriorly guided neural induction. Furthermore, acute exposure to VPA during the posterior induction step also retarded the subsequent neurulation-like tube morphogenesis process in neural organoid culture. These results suggest that VPA exposure during very early embryonic development might exhibit cytotoxicity and subsequently disrupt neural differentiation and morphogenesis processes.
3.The Differential Developmental Neurotoxicity of Valproic Acid on Anterior and Posterior Neural Induction of Human Pluripotent Stem Cells
Jeongah KIM ; Si-Hyung PARK ; Woong SUN
International Journal of Stem Cells 2025;18(1):49-58
Valproic acid (VPA), widely used as an antiepileptic drug, exhibits developmental neurotoxicity when exposure occurs during early or late pregnancy, resulting in various conditions ranging from neural tube defects to autism spectrum disorders. However, toxicity during the very early stages of neural development has not been addressed. Therefore, we investigated the effects of VPA in a model where human pluripotent stem cells differentiate into anterior or posterior neural tissues. Exposure to VPA during the induction of neural stem cells induced different developmental toxic effects in a dose-dependent manner. For instance, VPA induced cell death more profoundly during anteriorly guided neural progenitor induction, while inhibition of cell proliferation and enhanced differentiation were observed during posteriorly guided neural induction. Furthermore, acute exposure to VPA during the posterior induction step also retarded the subsequent neurulation-like tube morphogenesis process in neural organoid culture. These results suggest that VPA exposure during very early embryonic development might exhibit cytotoxicity and subsequently disrupt neural differentiation and morphogenesis processes.
4.Preoperative Shoulder MRI Findings to Predict Subscapularis Tendon Tear Requiring Surgical Repair
Ji-hoon JUNG ; Young-Hoon JO ; Yeo Ju KIM ; Seunghun LEE ; JeongAh RYU
Journal of the Korean Society of Radiology 2024;85(1):171-183
Purpose:
This study aimed to investigate which indirect parameters on preoperative MRI were the principal predictors of subscapularis tendon tears (STTs) requiring surgical repair.
Materials and Methods:
Preoperative MRI scans of 86 patients were retrospectively reviewed for visual assessment of the STT, pathology of the long head of the biceps tendon (LHBT), posterior decentering (PD) of the humeral head, humeral rotation, fatty degeneration, and subscapularis muscle atrophy. To evaluate atrophy, visual grading using the anatomical line connecting the coracoid tip to the glenoid base, designated as the base-to-tip line (BTL), and thickness measurements were performed in the en-face view.
Results:
Arthroscopically, 31 patients (36%) exhibited Lafosse type III or IV STT and underwent surgical repair. LHBT pathology (p = 0.002), PD of the humeral head (p = 0.012), fatty degeneration (p < 0.001), and BTL grade (p = 0.003) significantly correlated with STT. In the multivariate analysis, PD of the humeral head (p = 0.011, odds ratio [OR] = 5.14) and fatty degeneration (p = 0.046, OR = 2.81) were independent predictors of STT.
Conclusion
PD of the humeral head and fatty degeneration of the subscapularis can help to diagnose clinically significant STT. Interpretation of these findings may contribute to the planning of an optimal surgical strategy.
5.Preoperative Shoulder MRI Findings to Predict Subscapularis Tendon Tear Requiring Surgical Repair
Ji-hoon JUNG ; Young-Hoon JO ; Yeo Ju KIM ; Seunghun LEE ; JeongAh RYU
Journal of the Korean Society of Radiology 2024;85(1):171-183
Purpose:
This study aimed to investigate which indirect parameters on preoperative MRI were the principal predictors of subscapularis tendon tears (STTs) requiring surgical repair.
Materials and Methods:
Preoperative MRI scans of 86 patients were retrospectively reviewed for visual assessment of the STT, pathology of the long head of the biceps tendon (LHBT), posterior decentering (PD) of the humeral head, humeral rotation, fatty degeneration, and subscapularis muscle atrophy. To evaluate atrophy, visual grading using the anatomical line connecting the coracoid tip to the glenoid base, designated as the base-to-tip line (BTL), and thickness measurements were performed in the en-face view.
Results:
Arthroscopically, 31 patients (36%) exhibited Lafosse type III or IV STT and underwent surgical repair. LHBT pathology (p = 0.002), PD of the humeral head (p = 0.012), fatty degeneration (p < 0.001), and BTL grade (p = 0.003) significantly correlated with STT. In the multivariate analysis, PD of the humeral head (p = 0.011, odds ratio [OR] = 5.14) and fatty degeneration (p = 0.046, OR = 2.81) were independent predictors of STT.
Conclusion
PD of the humeral head and fatty degeneration of the subscapularis can help to diagnose clinically significant STT. Interpretation of these findings may contribute to the planning of an optimal surgical strategy.
6.Preoperative Shoulder MRI Findings to Predict Subscapularis Tendon Tear Requiring Surgical Repair
Ji-hoon JUNG ; Young-Hoon JO ; Yeo Ju KIM ; Seunghun LEE ; JeongAh RYU
Journal of the Korean Society of Radiology 2024;85(1):171-183
Purpose:
This study aimed to investigate which indirect parameters on preoperative MRI were the principal predictors of subscapularis tendon tears (STTs) requiring surgical repair.
Materials and Methods:
Preoperative MRI scans of 86 patients were retrospectively reviewed for visual assessment of the STT, pathology of the long head of the biceps tendon (LHBT), posterior decentering (PD) of the humeral head, humeral rotation, fatty degeneration, and subscapularis muscle atrophy. To evaluate atrophy, visual grading using the anatomical line connecting the coracoid tip to the glenoid base, designated as the base-to-tip line (BTL), and thickness measurements were performed in the en-face view.
Results:
Arthroscopically, 31 patients (36%) exhibited Lafosse type III or IV STT and underwent surgical repair. LHBT pathology (p = 0.002), PD of the humeral head (p = 0.012), fatty degeneration (p < 0.001), and BTL grade (p = 0.003) significantly correlated with STT. In the multivariate analysis, PD of the humeral head (p = 0.011, odds ratio [OR] = 5.14) and fatty degeneration (p = 0.046, OR = 2.81) were independent predictors of STT.
Conclusion
PD of the humeral head and fatty degeneration of the subscapularis can help to diagnose clinically significant STT. Interpretation of these findings may contribute to the planning of an optimal surgical strategy.
7.Feasibility of Ultrashort Echo Time T2* Mapping in Comparison With T2 Mapping for Quantitative Evaluation of Meniscal Degeneration
JeongAh RYU ; Sang Hoon LEE ; Soo Yeon CHOI ; Myung Jin SHIN ; Min Hee LEE ; Hye Won CHUNG
Investigative Magnetic Resonance Imaging 2023;27(1):49-55
Purpose:
This study aimed to assess the feasibility of ultrashort echo time (UTE)-T2* mapping in comparison with T2 mapping for quantitative evaluation of meniscal degeneration.
Materials and Methods:
This study included 208 menisci of 99 patients (59 women and 40 men, median age 52 years old [16–80 years]) who underwent knee MRI with both standard T2 mapping and UTE-T2* mapping sequences. A radiologist reviewed the images and graded meniscal degeneration according to the morphologic criteria on T2-weighted and proton density-weighted sequences. Manually drawn regions of interest were placed along the outline and hyperintensity subregion within the meniscus, and in the same location on midsagittal images of each T2 and UTE-T2* sequence. Meniscal T2 and T2* values (T2m and T2*m) as well as T2 and T2* values of hyperintensity subregions (T2h, T2*h) were calculated.
Results:
There was a strong correlation between T2m, T2*m, T2h, and T2*h, and morphological grades (correlation coefficient 0.793–0.943, 95% CI). On morphologic analysis, 50, 52, 50, and 56 menisci were graded as 0, 1, 2, and 3, respectively. T2m, T2*m, T2h, and T2*h were found to be significantly different in all the grades and tended to be higher in the more degraded meniscus (p < 0.001 for both). Mean T2m was 10.78 ± 2.91 ms, 15.81 ± 2.99 ms, 20.26 ± 3.19 ms, and 30.80 ± 7.38 ms and mean T2*m was 7.10 ± 1.12 ms, 9.64 ± 1.27 ms, 12.01 ± 1.58 ms, and 18.98 ± 4.67 ms for grades 0, 1, 2, and 3, respectively. Mean T2h was 20.05 ± 3.67 ms, 24.39 ± 4.73 ms, and 38.92 ± 9.49 ms and mean T2*h was 10.94 ± 1.65 ms, 13.67 ± 2.41 ms, and 22.36 ± 5.20 ms for grades 1, 2, and 3, respectively.
Conclusion
UTE-T2* mapping was feasible for quantitative evaluation of meniscal degeneration in patients. With a few improvements UTE-T2* mapping is a potential substitute for the standard T2 mapping, with improved efficacy.
9.Pathophysiology and MRI Findings of Infectious Spondylitis and the Differential Diagnosis
Sunjin RYU ; Yeo Ju KIM ; Seunghun LEE ; Jeongah RYU ; Sunghoon PARK ; Jung Ui HONG
Journal of the Korean Radiological Society 2021;82(6):1413-1440
On MRI, abnormal signals of the intervertebral disc, destruction of the upper and lower vertebral body endplate around the disc, and bone marrow edema around the endplate are considered typical findings of infectious spondylitis. These findings can also appear in various non-infectious spinal diseases, such as degenerative changes, acute Schmorl’s node, spondyloarthropathy, synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO), chronic recurrent multifocal osteomyelitis, and calcium pyrophosphate dihydrate crystal deposition disease. The imaging findings of infectious spondylitis that can be differentiated from these non-infectious spinal diseases on MRI are high signal intensity and abscess of the disc space, an abscess in the paraspinal soft tissue, and the loss of the linear low signal intensity on T1-weighted images of the bony endplate. However, these differentiation points do not always apply since there are many similarities in the imaging findings of infectious and non-infectious diseases. Therefore, for an accurate diagnosis, it is important to know the imaging characteristics related to the pathophysiology of not only infectious spondylitis but also non-infectious spinal diseases, which requires differentiation from infection.
10.Effects of the Experiences of Multicultural Education and Multicultural Contact on Cultural Competence among Korean Nursing Students
Health Communication 2019;14(1):17-24
BACKGROUND: The purpose of this study was to identify the level of cultural competence and effects of the experiences of multicultural education and multicultural contact on cultural competence among Korean nursing students.METHODS: This study involved 233 nursing students from two colleges. Data collection was conducted through questionnaires about the experiences of multicultural education, multicultural contact, and cultural competence.RESULTS: The main results were as follows. Cultural competence of participants was found to be moderate(M=3.45, SD=0.45). Among the experiences of multicultural education and multicultural contact, grade level, multicultural in-class education, multicultural education in non-cultural class, multicultural education in extra-curricular programs, the experience of caring for foreign patients, and acquiring multicultural information from mass-media were variables with a statistically significant correlation with cultural competence.CONCLUSION: When developing a program to enhance cultural competence, it is necessary to develop level-specific programs considering the differences by grade level, encourage extra-curricular activities, and construct systematic educational programs applying various teaching methods.
Cultural Competency
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Data Collection
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Education
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Humans
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Nursing
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Students, Nursing
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Teaching

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