1.Psychological Characteristics Associated With Cyberbullying:Focusing on the Victim-Perpetrators and Gender Differences
Geon-Taek BAE ; Sang-Ick LEE ; Chul-Jin SHIN ; Jung-Woo SON ; Siekyeong KIM ; Gawon JU ; Jeonghwan LEE ; Joon Hyung JUNG ; Seungwon CHUNG
Journal of the Korean Academy of Child and Adolescent Psychiatry 2026;37(2):95-104
Objectives:
Cyberbullying is a modern form of violence involving intentional harassment through electronic devices. We aimed to investigate how psychological characteristics differ based on cyberbullying involvement, identify the psychological factors associated with cyberbullying, and examine whether these factors vary by gender.
Methods:
A survey was conducted with 449 middle school students in Cheongju, Korea. Participants were categorized into four groups based on their involvement: Neither (N), Victim (V), Perpetrator (P), and Victim-Perpetrator (VP). Psychological characteristics were assessed using the Beck Depression Inventory (BDI), Self-Esteem Scale, and Strengths and Difficulties Questionnaire (SDQ). We compared these characteristics across the four groups and examined their influence on cyberbullying involvement by gender.
Results:
Overall, 31.8% of participants were involved in cyberbullying, with the VP group being the largest (17.1%) among them. The VP group exhibited more severe psychopathology than the N group across most internalizing and externalizing problems. SDQ-Conduct Problems subscale scores were significantly associated with victimization and perpetration. For female participants, high SDQEmotional Symptoms subscale scores were associated with greater victimization, and high BDI scores increased the risk of belonging to the VP group. No variables significantly increased the risk of belonging to the VP group among male participants.
Conclusion
Adolescents who are both victims and perpetrators of cyberbullying face the most significant psychological difficulties.Factors associated with cyberbullying involvement vary by gender, highlighting the need for tailored gender-specific prevention and intervention strategies.
2.Early Clinical Outcome of Hyperopic Small Incision Lenticule Extraction (SMILE) Using the VisuMax 800 in South Korea: A Pilot Study
Han Young CHUNG ; Young Taek CHUNG ; Bu Ki KIM ; In-Cheon YOU
Korean Journal of Ophthalmology 2026;40(3):280-291
Purpose:
This study evaluated the early outcomes of hyperopic small incision lenticule extraction (SMILE) using the VisuMax 800 femtosecond laser in a South Korean cohort, focusing on safety, efficacy, refractive predictability, and centration accuracy.
Methods:
This retrospective study included 11 eyes from seven patients who underwent hyperopic SMILE using the VisuMax 800 between December 1, 2024, and October 31, 2025, at Onnuri Eye Hospital in Jeonju, South Korea. All eyes completed at least 3 months of postoperative follow-up. Preoperative and postoperative evaluations included uncorrected and corrected distance visual acuity (CDVA), manifest refraction, tomography, and wavefront aberrometry. Outcomes were analyzed using the standard nine graphs for refractive surgery. Astigmatic changes were assessed using the Alpins vector method. Optical zone decentration was calculated using postoperative Placido-Scheimpflug topography.
Results:
The median preoperative spherical equivalent (SEQ) was +2.50 diopters (D) (interquartile range [IQR], 1.94–4.12 D). At 3 months, eight eyes (72.7%) were within ±0.50 D and all eyes (100%) were within ±1.00 D of the residual SEQ. The median efficacy index was 0.90 (IQR, 0.80–0.95). CDVA was unchanged in 63.6% of eyes and decreased by one line in 36.4%; no eye lost two or more lines. The median safety index was 0.86 (IQR, 0.80–1.00). Root mean square higher-order aberrations (RMS HOA) increased by +0.38 μm (IQR, 0.09–0.52 μm). The median vertex-based decentration was 0.064 mm (IQR, 0.036–0.091 mm). Decentration demonstrated a significant positive correlation with RMS HOA (rho = 0.709, p = 0.014).
Conclusions
Hyperopic SMILE using the VisuMax 800 produced favorable early clinical outcomes with high centration accuracy as well as shorter surgical time. Larger prospective studies with longer follow-up are necessary to determine long-term stability.
3.Imaging differentiation of hepatocellular carcinoma, combined hepatocellular-cholangiocarcinoma, and intrahepatic cholangiocarcinoma: pitfalls and advances
Jaeseung SHIN ; Taek CHUNG ; Sang Yun HA ; Hyungjin RHEE
Journal of Liver Cancer 2026;26(1):9-18
Accurate non-invasive differentiation of primary liver cancers, such as hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (iCCA), and combined hepatocellular-cholangiocarcinoma (cHCC-CCA), is crucial for optimal management but challenging due to shared risk factors and overlapping imaging phenotypes. While the Liver Imaging Reporting and Data System category M effectively captures the classic targetoid appearance of large duct type iCCA, the small duct type frequently exhibits HCC-mimicking non-rim arterial phase hyperenhancement and non-peripheral washout, potentially compromising diagnostic specificity. Furthermore, cHCC-CCA presents a formidable diagnostic dilemma, existing on a continuous imaging spectrum that reflects its histologic dominance. This continuous imaging spectrum not only blurs radiologic distinctions but also complicates tissue sampling, limiting the diagnostic accuracy of core needle biopsies and highlighting the risk of misclassification. To enhance diagnostic clarity, this review highlights their key imaging hallmarks: while HCC typically shows non-rim arterial phase hyperenhancement (APHE) and non-peripheral washout, large duct iCCA displays a classic targetoid appearance with rim APHE and progressive central enhancement. Conversely, small duct iCCA often mimics HCC, and cHCC-CCA exhibits a variable spectrum depending on its predominant histologic component. Ultimately, overcoming these diagnostic pitfalls requires a rigorous, multidisciplinary approach that synthesizes imaging findings, serologic tumor markers, and clinical contexts.
4.Combined hepatocellular-cholangiocarcinoma: a contemporary pathologic and molecular perspective
Journal of Liver Cancer 2026;26(1):1-8
Combined hepatocellular cholangiocarcinoma (cHCC-CCA) is a rare primary liver carcinoma characterized by the unequivocal coexistence of hepatocytic and cholangiocytic differentiation within a single tumor. Despite its low incidence, cHCC-CCA has received considerable attention because of its marked histologic heterogeneity, diagnostic challenges, and poorer clinical outcomes than conventional hepatocellular carcinoma. Historically, the biological nature of cHCC-CCA has been controversial, with competing hypotheses, including derivation from hepatic progenitor cells, collision of independent tumors, and transdifferentiation between hepatocytic and biliary lineages. Recent advances in genomic and transcriptomic profiling have substantially improved this understanding. Accumulating evidence indicates that most cHCC-CCAs arise from a common clonal origin and subsequently undergo divergent differentiation rather than representing true collision tumors. Transcriptomic analyses further demonstrate that cHCC-CCAs span a biological continuum between hepatocellular- and cholangiocytic-like states, with intermediate tumors characterized by lineage plasticity, activation of developmental pathways, and heterogeneous tumor microenvironments. This review provides a pathology- centered overview of cHCC-CCAs, summarizing the key histopathological features and the supportive role of immunohistochemistry, followed by an integrated discussion of recent genomic, transcriptomic, and immune profiling studies. Additionally, it highlights emerging applications of artificial intelligence and digital pathology, which may assist in biological stratification. Collectively, the current evidence supports viewing cHCC-CCA not as a single static entity, but as a spectrum of primary liver carcinomas unified by lineage plasticity, underscoring the importance of integrated pathological and multi-omics approaches for future classification and research.
5.Molecular determinants of outcome to gemcitabine, cisplatin, and nab-paclitaxel in patients with advanced biliary tract cancer
Daeseong KIM ; Nam Suk SIM ; Seonjeong WOO ; Min Hwan KIM ; Choong-kun LEE ; Seung Soo HONG ; Sung Hyun KIM ; Ho Kyoung HWANG ; Chang Moo KANG ; Woo Jung LEE ; Jung Hyun JO ; Taek CHUNG ; Sohyun HWANG ; Beodeul KANG ; Jung Sun KIM ; Chang-Il KWON ; Sangwoo KIM ; Hong Jae CHON ; Chang Gon KIM ; Young Nyun PARK ; Hye Jin CHOI
Clinical and Molecular Hepatology 2026;32(2):721-736
Background/Aims:
Biliary tract cancer (BTC) is a rare malignancy with poor prognosis. We investigated genomic determinants of clinical benefit from gemcitabine, cisplatin, and nab-paclitaxel (GAP) versus gemcitabine and cisplatin (GC) in advanced BTC.
Methods:
Clinical and genomic data using TruSight Oncology 500 were analyzed from patients treated with GAP (N=198) or GC (N=89) as first-line therapy.
Results:
With a median follow-up of 33.0 months, GAP modestly improved progression-free survival (PFS) (hazard ratio [HR] 0.764; 95% confidence interval [CI] 0.591–0.989) without significant overall survival (OS) difference compared to GC. Genomic profiling revealed frequent alterations in TP53 (35.2%), KRAS (16.4%), SMAD4 (10.5%), and TNFRSF14 (10.5%), involving RTK/RAS (44.3%), TP53 (41.8%), and PI3K (20.2%) pathways. Single-gene mutations did not predict treatment benefit. However, pathway-level analysis identified PI3K pathway activation as significantly associated with inferior PFS (HR 2.148; 95% CI 1.478–3.124) and OS (HR 2.096; 95% CI 1.413–3.109) in patients receiving GAP, an effect not observed with GC. Importantly, GAP conferred clinical benefit only in patients without PI3K pathway activation, while no survival advantage was seen in those with such alterations (Pinteraction=0.023 for PFS, Pinteraction=0.003 for OS). Similar results were obtained in the independent validation cohort treated with GAP (N=103) or GC (N=64) for BTC.
Conclusions
Genomic profiling using next-generation sequencing identified PI3K pathway activation as key molecular determinant that differentiates patient outcomes between GAP and GC treatments in advanced BTC.
6.Hepatic Angiomyolipoma With Hemorrhagic Degeneration:A Case Report
Seung Hyun PARK ; Taek CHUNG ; Young Nyun PARK ; Dai Hoon HAN ; Hyungjin RHEE
Investigative Magnetic Resonance Imaging 2026;30(1):62-67
Hepatic angiomyolipoma is a rare benign tumor that often mimics hepatocellular carcinoma on imaging. Here, we report a rare case of hepatic angiomyolipoma with extensive hemorrhagic degeneration, resulting in a large hemorrhagic component that mimicked a complicated cystic neoplasm. A 43-year-old woman presented with mild abdominal distension, and imaging revealed a 16-cm multiloculated cystic mass in the left hepatic lobe. Computed tomography revealed a thick, enhancing wall and septa with hyperattenuating internal fluid. On gadoxetic acid-enhanced magnetic resonance imaging, arterial enhancement was observed along the thick wall, and a subtle opposedphase signal drop indicated a small fat component that was initially missed. Laparoscopic left lobectomy was performed under suspicion of a malignant cystic neoplasm. Histopathological examination revealed an angiomyolipoma composed of thick-walled vessels, spindle-shaped muscle bundles, and scant adipocytes, with human melanoma black 45 positivity and absence of an epithelial lining, consistent with hemorrhagic degeneration. This case highlights how hemorrhagic degeneration can pose a significant diagnostic challenge by masking the typical features of hepatic angiomyolipoma, leading to diagnostic confusion with complicated cystic tumors.
7.Bisphenol Analogs Downregulate the Self-Renewal Potential of Spermatogonial Stem Cells
Seo-Hee KIM ; Seung Hee SHIN ; Seok-Man KIM ; Sang-Eun JUNG ; Beom-Jin SHIN ; Jin Seop AHN ; Kyoung Taek LIM ; Dong-Hwan KIM ; Kichoon LEE ; Buom-Yong RYU
The World Journal of Men's Health 2025;43(1):154-165
Purpose:
In this study, we investigated the effect of bisphenol-A (BPA) and its major analogs, bisphenol-F (BPF), and bisphenol-S (BPS), on spermatogonial stem cells (SSCs) populations using in vitro SSC culture and in vivo transplantation models.
Materials and Methods:
SSCs enriched from 6- to 8-day-old C57BL/6-eGFP+ male mice testes were treated with varying concentrations of bisphenols for 7 days to examine bisphenol-derived cytotoxicity and changes in SSC characteristics. We utilized flow cytometry, immunocytochemistry, real-time quantitative reverse transcription-PCR, and western blot analysis. The functional alteration of SSCs was further investigated by examining donor SSC-derived spermatogenesis evaluation through in vivo transplantation and subsequent testis analysis.
Results:
BPF exhibited a similar inhibitory effect on SSCs as BPA, demonstrating a significant decrease in SSC survival, inhibition of proliferation, and induction of apoptosis. On the other hand, while BPS was comparatively weaker than BPA and BPF, it still showed significant SSC cytotoxicity. Importantly, SSCs exposed to BPA, BPF, and BPS exhibited a significant reduction in donor SSC-derived germ cell colonies per total number of cultured cells, indicating that, like BPA, BPF, and BPS can induce a comparable reduction in functional SSCs in the recipient animals. However, the progress of spermatogenesis, as evidenced by histochemistry and the expressions of PCNA and SSC specific markers, collectively indicates that BPA, BPF, and BPS may not adversely affect the spermatogenesis.
Conclusions
Our findings indicate that the major BPA substitutes, BPF and BPS, have significant cytotoxic effects on SSCs, similar to BPA. These effects may lead to a reduction in the functional self-renewal stem cell population and potential impacts on male fertility.
8.Powered Tool for the Removal of a Well-Fixed Acetabular Cup: A Comparative Experimental Study
Jun Young CHUNG ; Yonghan CHA ; Chang-Ho JUNG ; Jin-Woo KIM ; Jun-Il YOO ; Jung-Taek KIM ; Yongho JEON
Clinics in Orthopedic Surgery 2025;17(3):372-380
Background:
The removal of a well-fixed acetabular cup is a challenging, labor-intensive, and time-consuming step during revision hip arthroplasty. Although the advent of the manual osteotome, Explant, has simplified the procedure, it is still a stressful process as it dissipates the surgeon’s strength and time and risks an iatrogenic pelvic fracture. Recently, EZX, a powered tool for extraction of well-fixed acetabular cups with semicircular blade was invented. This study aimed to compare Explant and EZX in an experimental condition for their efficacy and safety.
Methods:
Cementless acetabular cups were press-fitted to 20 hemipelvic polyurethane models using foam adhesives. Ten cups were removed with each tool for comparison of the elapsed time, loads on the entire hemipelvis, periacetabular strain and temperature, volume of periacetabular bone removed, and diameter of the remaining acetabular rim. Strains and loads were quantitatively assessed using strain gauges and load cells for precise and reliable measurements.
Results:
The mean duration required to remove a well-fixed cup with EZX was 38.5 seconds (range, 25–55), whereas that with Explant was 543.7 seconds (range, 214–1,051) (p < 0.001). The load on the entire hemipelvis with EZX (mean, 9.1 kgf; range, 6.4–11.3) was 33% lower than that with Explant (mean, 13.6 kgf; range, 9.2–17.1) (p < 0.001). The periacetabular peak strains at the 3 positions with EZX were significantly lower than those with Explant (p < 0.001). The temperature during the removal did not differ significantly between the 2 tools. Although the mean volume of bone loss with Explant was 2.4 mL more than that with EZX (p < 0.001), the mean diameters of the remaining acetabular rim were not significantly different, measuring 54.1 mm with both tools.
Conclusions
The present experiment revealed that a well-fixed cup could be removed using a powered tool with less strength and time and less load on the entire pelvis. Although the powered tool removed a larger volume of bone, the diameters of the remaining acetabular rims were equivalent. This tool may help surgeons remove well-fixed cups in a short time and reduce the deforming load on the bone around the cup without increasing the size of the subsequent reconstruction cup.
9.Bisphenol Analogs Downregulate the Self-Renewal Potential of Spermatogonial Stem Cells
Seo-Hee KIM ; Seung Hee SHIN ; Seok-Man KIM ; Sang-Eun JUNG ; Beom-Jin SHIN ; Jin Seop AHN ; Kyoung Taek LIM ; Dong-Hwan KIM ; Kichoon LEE ; Buom-Yong RYU
The World Journal of Men's Health 2025;43(1):154-165
Purpose:
In this study, we investigated the effect of bisphenol-A (BPA) and its major analogs, bisphenol-F (BPF), and bisphenol-S (BPS), on spermatogonial stem cells (SSCs) populations using in vitro SSC culture and in vivo transplantation models.
Materials and Methods:
SSCs enriched from 6- to 8-day-old C57BL/6-eGFP+ male mice testes were treated with varying concentrations of bisphenols for 7 days to examine bisphenol-derived cytotoxicity and changes in SSC characteristics. We utilized flow cytometry, immunocytochemistry, real-time quantitative reverse transcription-PCR, and western blot analysis. The functional alteration of SSCs was further investigated by examining donor SSC-derived spermatogenesis evaluation through in vivo transplantation and subsequent testis analysis.
Results:
BPF exhibited a similar inhibitory effect on SSCs as BPA, demonstrating a significant decrease in SSC survival, inhibition of proliferation, and induction of apoptosis. On the other hand, while BPS was comparatively weaker than BPA and BPF, it still showed significant SSC cytotoxicity. Importantly, SSCs exposed to BPA, BPF, and BPS exhibited a significant reduction in donor SSC-derived germ cell colonies per total number of cultured cells, indicating that, like BPA, BPF, and BPS can induce a comparable reduction in functional SSCs in the recipient animals. However, the progress of spermatogenesis, as evidenced by histochemistry and the expressions of PCNA and SSC specific markers, collectively indicates that BPA, BPF, and BPS may not adversely affect the spermatogenesis.
Conclusions
Our findings indicate that the major BPA substitutes, BPF and BPS, have significant cytotoxic effects on SSCs, similar to BPA. These effects may lead to a reduction in the functional self-renewal stem cell population and potential impacts on male fertility.
10.Bisphenol Analogs Downregulate the Self-Renewal Potential of Spermatogonial Stem Cells
Seo-Hee KIM ; Seung Hee SHIN ; Seok-Man KIM ; Sang-Eun JUNG ; Beom-Jin SHIN ; Jin Seop AHN ; Kyoung Taek LIM ; Dong-Hwan KIM ; Kichoon LEE ; Buom-Yong RYU
The World Journal of Men's Health 2025;43(1):154-165
Purpose:
In this study, we investigated the effect of bisphenol-A (BPA) and its major analogs, bisphenol-F (BPF), and bisphenol-S (BPS), on spermatogonial stem cells (SSCs) populations using in vitro SSC culture and in vivo transplantation models.
Materials and Methods:
SSCs enriched from 6- to 8-day-old C57BL/6-eGFP+ male mice testes were treated with varying concentrations of bisphenols for 7 days to examine bisphenol-derived cytotoxicity and changes in SSC characteristics. We utilized flow cytometry, immunocytochemistry, real-time quantitative reverse transcription-PCR, and western blot analysis. The functional alteration of SSCs was further investigated by examining donor SSC-derived spermatogenesis evaluation through in vivo transplantation and subsequent testis analysis.
Results:
BPF exhibited a similar inhibitory effect on SSCs as BPA, demonstrating a significant decrease in SSC survival, inhibition of proliferation, and induction of apoptosis. On the other hand, while BPS was comparatively weaker than BPA and BPF, it still showed significant SSC cytotoxicity. Importantly, SSCs exposed to BPA, BPF, and BPS exhibited a significant reduction in donor SSC-derived germ cell colonies per total number of cultured cells, indicating that, like BPA, BPF, and BPS can induce a comparable reduction in functional SSCs in the recipient animals. However, the progress of spermatogenesis, as evidenced by histochemistry and the expressions of PCNA and SSC specific markers, collectively indicates that BPA, BPF, and BPS may not adversely affect the spermatogenesis.
Conclusions
Our findings indicate that the major BPA substitutes, BPF and BPS, have significant cytotoxic effects on SSCs, similar to BPA. These effects may lead to a reduction in the functional self-renewal stem cell population and potential impacts on male fertility.

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