1.Molecular phylogeny and morphometric divergence of native Korean wild mice (Musmusculus)
Daewoo KIM ; Jooseong OH ; Jang Geun OH ; Hee-Young YANG ; Geun-Joong KIM ; Tae-Hoon LEE ; Bae-Keun LEE ; Chungoo PARK ; Dong-Ha NAM
Laboratory Animal Research 2026;42(1):68-81
Background:
The taxonomic status of house mice (Mus musculus) on the Korean Peninsula has long been debated due to conflicting morphological classifications and limited genetic evidence. Historically, three subspecies (M. m.molossinus, M. m. utsuryonis, and M. m. yamashinai) have been proposed based on external traits, although the validity of these proposals remains uncertain. Thus, this study aimed to integrate genetic and morphological analyses to clarify the phylogenetic relationships of Korean mice relative to the well-known primary M. musculus subspecies and evaluate the taxonomic distinctiveness.
Results:
Genetic analysis of mitochondrial DNA (cytb gene) from mice across Korea, including islands, mountains, and agricultural fields, confirmed that these mice belong to the Eurasian M. m. musculus lineage. Morphologically, Korean mice exhibited tail ratios consistent with previously assigned subspecies, suggesting these traits represent intraspecific variation within M. m. musculus. Craniometric analyses revealed distinctive features, such as a shorter, narrower premaxillary tooth-patch width and a longer maxillary tooth-row length, thereby distinguishing these mice from laboratory strains derived from M. m. domesticus. These cranial configurations, visualized via three-dimensional micro-computed tomography scans, further supported the morphological divergence of these mice from other subspecies.
Conclusions
Our findings indicate that Korean house mice belong to a single subspecific group within M. m.musculus, with observed morphological variations reflecting local adaptation rather than distinct taxonomic divisions.The Korean Peninsula likely served as an ecological bridge, facilitating the spatiotemporal diversification of M. m.musculus across East Eurasia. This study resolves longstanding taxonomic ambiguities and underscores the subspecific status of Korean house mice within M. m. musculus. These insights provide a foundation for understanding the biogeographic history of human commensal species and future biomedical research utilizing wild-derived mouse models.
2.Eligibility and causes of disqualification among living liver donor candidates: A single-center analysis of 991 candidates
Eun-Ju NAM ; Jong-Hyun KIM ; Hae-In SHIN ; Young-In YOON ; Deok-Bog MOON ; Ki-Hun KIM ; Tae-Yong HA ; Gi-Won SONG ; Dong-Hwan JUNG ; Gil-Chun PARK ; Shin HWANG ; Sung-Gyu LEE
Annals of Liver Transplantation 2026;6(1):17-24
Background:
A systematic evaluation of potential living liver donors is essential to ensure donor safety and optimize recipient outcomes in living donor liver transplantation (LDLT). This study aimed to assess donor acceptance rates and reasons for disqualification among individuals evaluated for LDLT at a high-volume transplant center over a one-year period.
Methods:
We retrospectively reviewed 1,087 potential living liver donors who presented for LDLT evaluation in 2023. Of these, 991 candidates advanced beyond the initial screening (Stage 1) and underwent comprehensive clinical, imaging, and pathological assessments (Stages 2 and 3). Candidates who discontinued after Stage 1 were excluded due to the absence of documented reasons for non-progression.
Results:
Among the 991 candidates who proceeded beyond initial screening, 473 (47.7%) completed the full donor evaluation, of whom 466 were judged to be suitable donors. Among suitable donors, 384 (82.4%) proceeded to donor hepatectomy, whereas 82 did not, primarily due to recipient-related factors such as clinical deterioration or withdrawal of consent. Donor ineligibility was determined in 422 candidates (42.6%), most commonly due to inadequate remnant liver volume (52.8%), hepatic steatosis (20.6%), and insufficient graft size (10.2%). Among candidates undergoing Stage 2 evaluation, 162 (16.3%) failed to meet steatosis criteria; 126 were excluded solely for steatosis and advised weight reduction, and 39 subsequently became eligible and successfully donated.
Conclusion
In this high-volume LDLT center, donor disqualification was primarily driven by remnant liver volume and hepatic steatosis. Targeted interventions such as weight reduction enabled successful donation in a subset of initially ineligible candidates, underscoring the importance of individualized donor evaluation and pre-donation optimization.
3.Effect of 50-Hz Filters on Pattern Electroretinogram
Dong Hee HA ; Nam Ju MOON ; Ungsoo Samuel KIM
Korean Journal of Ophthalmology 2025;39(3):241-245
Purpose:
Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results.
Methods:
This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated.
Results:
A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare.
Conclusions
Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.
4.Effect of 50-Hz Filters on Pattern Electroretinogram
Dong Hee HA ; Nam Ju MOON ; Ungsoo Samuel KIM
Korean Journal of Ophthalmology 2025;39(3):241-245
Purpose:
Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results.
Methods:
This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated.
Results:
A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare.
Conclusions
Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.
5.Effect of 50-Hz Filters on Pattern Electroretinogram
Dong Hee HA ; Nam Ju MOON ; Ungsoo Samuel KIM
Korean Journal of Ophthalmology 2025;39(3):241-245
Purpose:
Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results.
Methods:
This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated.
Results:
A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare.
Conclusions
Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.
6.Effect of 50-Hz Filters on Pattern Electroretinogram
Dong Hee HA ; Nam Ju MOON ; Ungsoo Samuel KIM
Korean Journal of Ophthalmology 2025;39(3):241-245
Purpose:
Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results.
Methods:
This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated.
Results:
A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare.
Conclusions
Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.
7.Effect of 50-Hz Filters on Pattern Electroretinogram
Dong Hee HA ; Nam Ju MOON ; Ungsoo Samuel KIM
Korean Journal of Ophthalmology 2025;39(3):241-245
Purpose:
Pattern electroretinogram (PERG) is used to evaluate the function of retinal ganglion cells. However, the amplitude of PERG is quite small, making the examination challenging to perform. Waveform noise may be minimized by applying various filters. We aimed to investigate the effect of 50-Hz filters on PERG test results.
Methods:
This is the retrospective observational study. PERG tests were performed using the RETI-scan system according to the International Society for Clinical Electrophysiology of Vision guidelines. Three types of 50-Hz filters (soft, middle, and hard) were applied. The differences in parameters (N35 peak time, P50 peak time, N95 peak time, P50 amplitude, N95 amplitude, and N95 to P50 ratio) were analyzed. Based on the provided normal range, the changes from normal to abnormal range or vice versa were investigated.
Results:
A total of 24 waveforms were analyzed. After filtering, the P50 and N95 amplitudes showed a significant reduction of 8% to 15% (P50 amplitude: 5.1 ± 2.7 μV without filter, 4.6 ± 2.3 μV with 50-Hz soft filter, 4.3 ± 2.1 μV with 50-Hz middle filter, 4.3 ± 2.1 μV with 50-Hz hard filter; N95 amplitude: 7.2 ± 4.2 μV without filter, 6.6 ± 3.8 μV with 50-Hz soft filter, 6.3 ± 3.6 μV with 50-Hz middle filter, 6.1 ± 3.6 μV with 50-Hz hard filter). This pattern was more prominent in normal subjects. All latencies except the N35 peak time exhibited no differences between the tests. The N95 to P50 ratio decreased after 50-Hz middle and hard filtering. Considering the normative data, switching between normal and abnormal results was rare.
Conclusions
Although peak time was not significantly affected, amplitude was significantly reduced after using 50-Hz filters. Thus, 50-Hz filters can smoothen the waveform. Nevertheless, caution must be exercised while taking readings.
8.Dual Specificity Phosphatase 27 Regulates Pluripotency and Meso-Endodermal Differentiation by Interacting with Transcription Factor CP2 Like-1 in Embryonic Stem Cells
Sujin SONG ; Jinbeom HEO ; Siwon LEE ; Yun Ji NAM ; YongHwan KIM ; Hyein JU ; Hyungu KWON ; Hyun Jun IM ; Seok Woo HA ; Hyun Ji KIM ; Dabin LEE ; Sang Jin PARK ; Sang Hoon SONG ; Juhyun PARK ; Eui Man JEONG ; Kyunggon KIM ; Dong-Myung SHIN ; Seungun LEE
International Journal of Stem Cells 2025;18(4):412-425
Transcription factor CP2-like protein 1 (Tfcp2l1), a naïve pluripotency transcription factor, is expressed in both early embryonic and adult tissues, where it enforces pluripotency of embryonic stem cells (ESCs) and stemness features of cancer cells, respectively. However, the detailed molecular pathways by which Tfcp2l1 is regulated in early embryonic development and cancer cells remain unknown. Here, we identified the pseudophosphatase dual specificity phosphatase 27 (Dusp27), also known as serine/threonine/tyrosine-interacting like-2, as a novel Tfcp2l1-interacting protein through a sterile alpha motif-like domain in the C-terminus of Tfcp2l1 in murine ESCs. The interaction between Dusp27 and Tfcp2l1 was dependent on the cell cycle status and increased during mitosis. Expression of Dusp27 was upregulated during naïve pluripotency and repressed during spontaneous differentiation of murine ESCs. Ectopic expression of Dusp27 enhanced the transcriptional activity of Tfcp2l1 and promoted features associated with the naïve pluripotent state, while suppressing meso-endodermal lineage differentiation. The present study demonstrates that Dusp27 is a novel positive regulator of Tfcp2l1 through a physical interaction and thereby fine-tunes the pluripotency status and meso-endodermal differentiation of murine ESCs.
9.Sex Difference in the Effect of Bifidobacterium longum on Repeated Water Avoidance Stress-induced Gut Dysbiosis in Wistar Rats
Soo In CHOI ; Nayoung KIM ; Ryoung Hee NAM ; Jae Young JANG ; Eun Hye KIM ; SungChan HA ; Kisung KANG ; Wonseok LEE ; Cheol Min SHIN ; Dong Ho LEE
Journal of Cancer Prevention 2024;29(1):16-23
Dysbiosis in gut microbiota is known to contribute to development of irritable bowel syndrome. We tried to investigate the effect of Bifidobacterium longum on repeated water avoidance stress (WAS) in a Wistar rat model. The three groups (no-stress, WAS, and WAS with B. longum) of rats were allocated to sham or WAS for 1 hour daily for 10 days, and B. longum was administered through gavage for 10 days. Fecal pellet numbers were counted at the end of each 1-hour session of WAS. After 10 days of repeated WAS, the rats were eutanized, and the feces were collected. WAS increased fecal pellet output (FPO) significantly in both sexes (P < 0.001), while the female B. longum group showed significantly decreased FPO (P = 0.005). However, there was no consistent change of myeloperoxidase activity and mRNA expression of interleukin-1ββ and TNF-αα. Mast cell infiltration at colonic submucosa increased in the female WAS group (P = 0.016). In terms of fecal microbiota, the repeated WAS groups in both sexes showed different beta-diversity compared to control and WAS with B. longum groups. WAS-induced mast cell infiltration was reduced by the administration of B. longum in female rats. Moreover, administration of B. longum relieved WAS-caused dysbiosis, especially in female rats. In conclusion, B. longum was beneficial for WAS-induced stress in rats, especially in females.
10.Fracture Liaison Service in Korea: 2022 Position Statement of the Korean Society for Bone and Mineral Research
Jae-Young LIM ; Young Yul KIM ; Jin-Woo KIM ; Seongbin HONG ; Kyunghoon MIN ; Jaewon BEOM ; Byung-Ho YOON ; Sang Yoon LEE ; Sung Hye KONG ; Jun-Il YOO ; Myung Sook PARK ; Jae-Hwi NHO ; Sangbong KO ; Min Wook JOO ; Dong Hwan KIM ; Chan Ho PARK ; Tae-Young KIM ; Seil SOHN ; So Young PARK ; A Ram HONG ; Young Joo KWON ; Sung Bae PARK ; Young-Kyun LEE ; Nam Hoon MOON ; Bo Ryun KIM ; Yongsoon PARK ; Yonghan CHA ; Yong-Chan HA
Journal of Bone Metabolism 2023;30(1):31-36
Osteoporosis and osteoporotic fractures cause socioeconomic concerns, and medical system and policies appear insufficient to prepare for these issues in Korea, where the older adult population is rapidly increasing. Many countries around the world are already responding to osteoporosis and osteoporotic fractures by adopting fracture liaison service (FLS), and such an attempt has only begun in Korea. In this article, we introduce the operation methods for institutions implementing FLS and characteristics of services, and activities of the FLS Committee for FLS implementation in the Korean Society for Bone and Mineral Research. In addition, we hope that the current position statement will contribute to the implementation of FLS in Korea and impel policy changes to enable a multidisciplinary and integrated FLS operated under the medical system.

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