2.A Novel Approach for Estimating the Effective Atomic Number Using Dual Energy
Jeong Heon KIM ; So Hyun AHN ; Kwang Woo PARK ; Jin Sung KIM
Progress in Medical Physics 2025;36(1):1-7
Purpose:
This study aimed to present a novel method for estimating the effective atomic number(Zeff ) using dual-energy computed tomography (DECT) designed to improve accuracy andstreamline clinical workflows by reducing computational complexity.
Methods:
The proposed model leverages the DECT-derived mass attenuation coefficients without detailed compositional analysis. By incorporating additional parameters into the conventional Rutherford model, such as exponential and trigonometric functions, the model effectively capturescomplex variations in attenuation, enabling precise Zeff estimation. Model fitting was performedusing dual-energy data and evaluated using the percentage difference in error rates.
Results:
Compared with the Rutherford model, which recorded a maximum error rate of 0.55%, the proposed model demonstrated a significantly lower maximum error rate of 0.15%, highlightingits precision. Zeff estimates for various materials closely matched the reference values, confirmingthe improved accuracy of the model.
Conclusions
The proposed DECT-based model provides a practical and efficient approach to Zeff estimation, with potential applications in radiation oncology, particularly for accurate stopping power ratio calculations in proton and heavy ion therapies.
3.Prosthetic treatment of velopharyngeal insufficiency using maxillary obturator in an edentulous patient with Passavant’s ridge
Yun-A KIM ; Chang-Mo JEONG ; Mi-Jung YUN ; Jung-Bo HUH ; So-Hyoun LEE
The Journal of Korean Academy of Prosthodontics 2025;63(2):164-175
This case report presents an 81-year-old edentulous female patient with congenital cleft lip and palate, rehabilitated with a maxillary obturator and a mandibular complete denture. A defect in the hard palate causes nasal leakage and hypernasalization of speech. Velopharyngeal insufficiency due to a defect in the soft palate causes reflux during swallowing and decreased clarity of pronunciation.The anatomical structures, such as Passavant’s ridge, were considered to prevent respiratory problems when impression taking. We achieved satisfactory results including velopharyngeal closure for pronunciation, mastication, and swallowing, as well as improved aesthetics. Therefore, we report the process and considerations of the treatment.
4.The mutual interaction of TRPC5 channel with polycystin proteins
Misun KWAK ; Hana KANG ; Jinhyeong KIM ; Yejun HONG ; Byeongseok JEONG ; Jongyun MYEONG ; Insuk SO
The Korean Journal of Physiology and Pharmacology 2025;29(1):93-108
PKD1 regulates a number of cellular processes through the formation of complexes with the PKD2 ion channel or transient receptor potential classical (TRPC) 4 in the endothelial cells. Although Ca 2+ modulation by polycystins has been reported between PKD1 and TRPC4 channel or TRPC1 and PKD2, the function with TRPC subfamily regulated by PKD2 has remained elusive. We confirmed TRPC4 or TRPC5 channel activation via PKD1 by modulating G-protein signaling without change in TRPC4/C5 translocation. The activation of TRPC4/C5 channels by intracellular 0.2 mM GTPγS was not significantly different regardless of the presence or absence of PKD1. Furthermore, the C-terminal fragment (CTF) of PKD1 did not affect TRPC4/C5 activity, likely due to the loss of the N-terminus that contains the G-protein coupled receptor proteolytic site (GPS). We also investigated whether TRPC1/C4/C5 can form a heterodimeric channel with PKD2, despite PKD2 being primarily retained in the endoplasmic reticulum (ER). Our findings show that PKD2 is targeted to the plasma membrane, particularly by TRPC5, but not by TRPC1. However, PKD2 did not coimmunoprecipitate with TRPC5 as well as with TRPC1. PKD2 decreased both basal and La 3+ -induced TRPC5 currents but increased M 3 R-mediated TRPC5 currents. Interestingly, PKD2 increased STAT3 phosphorylation with TRPC5 and decreased STAT1 phosphorylation with TRPC1. To be specific, PKD2 and TRPC1 compete to bind with TRPC5 to modulate intracellular Ca 2+ signaling and reach the plasma membrane. This interaction suggests a new therapeutic target in TRPC5 channels for improving vascular endothelial function in polycystic kidney disease.
5.Microglial galectin-3 increases with aging in the mouse hippocampus
Hyun Joo SHIN ; So Jeong LEE ; Hyeong Seok AN ; Ha Nyeoung CHOI ; Eun Ae JEONG ; Jaewoong LEE ; Kyung Eun KIM ; Bong-Hoi CHOI ; Seung Pil YUN ; Dawon KANG ; Sang Soo KANG ; Gu Seob ROH
The Korean Journal of Physiology and Pharmacology 2025;29(2):215-225
Microglial activation during aging is associated with neuroinflammation and cognitive impairment. Galectin-3 plays a crucial role in microglial activation and phagocytosis. However, the role of galectin-3 in the aged brain is not completely understood. In the present study, we investigated aging-related mechanisms and microglial galectin-3 expression in the mouse hippocampus using female 6-, 12-, and 24-month-old C57BL/6 mice. Western blot analysis revealed neurodegeneration, blood-brain barrier leakage, and increased levels of neuroinflammation-related proteins in 24-month-old mice compared to 6- and 12-month-old mice. Immunohistochemistry revealed an increase in activated microglia in the hippocampus of 24-month-old mice compared to 6- and 12-month-old mice. Furthermore, we found more galectin-3 and triggering receptor expressed on myeloid cells-2-positive microglia in 24-month-old mice compared to 6- and 12-month-old mice. Using primary mouse microglial cells, galectin -3 was also increased by lipopolysaccharide treatment. These findings suggest that galectin-3 may play an important role in microglial activation and neuroinflammation during brain aging.
6.Reduction of Low-Density Lipoprotein Cholesterol by Mesenchymal Stem Cells in a Mouse Model of Exogenous Cushing’s Syndrome
Yu-Hee KIM ; Seonghee JEONG ; Kyung-Ah CHO ; So-Youn WOO ; Seung-Ho HAN ; Kyung-Ha RYU
Tissue Engineering and Regenerative Medicine 2025;22(2):237-248
BACKGROUND:
Exogenous Cushing’s syndrome, which results from prolonged glucocorticoid treatment, is associated with metabolic abnormalities. Previously, we reported the inhibitory effect of tonsil-derived mesenchymal stem cell conditioned medium (T-MSC CM) on glucocorticoid signal transduction. In this study, we investigated the therapeutic efficacy of T-MSCs in a mouse model of exogenous Cushing’s syndrome.
METHODS:
Exogenous Cushing’s syndrome model mice was generated by corticosterone administration in the drinking water for 5 weeks, and T-MSCs were injected intraperitoneally twice during the third week. Serum lipid profiles were measured using a chemistry analyzer. HepG2 cells were treated with dexamethasone and co-cultured with T-MSCs.Expression levels of genes involved in cholesterol metabolism were examined using real-time PCR. Low-density lipoprotein receptor (LDLR) protein levels were determined using western blotting and immunohistochemistry. Liver RNA extracted from the CORT and CORT ? MSC mouse groups was used for transcriptome sequencing analysis and protein– protein interaction analysis.
RESULTS:
Weight reduction and improvements in dyslipidemia by T-MSC administration were observed only in female mice. T-MSCs reduce circulating LDL cholesterol levels by downregulating liver X receptor a (LXRa) and inducible degrader of LDLR (IDOL) expression, thereby stabilizing LDLRs in the liver. Transcriptome analysis of liver tissue revealed pathways that are regulated by T-MSCs administration.
CONCLUSION
Administration of MSCs to female mice receiving chronic corticosterone treatment reduced the circulating LDL cholesterol level by downregulating the LXRa–IDOL axis in hepatocytes. These results suggest that T-MSCs may offer a novel therapeutic strategy for managing exogenous Cushing’s syndrome by regulating cholesterol metabolism.
7.Effects of hepatic fibrosis on the quantification of hepatic steatosis using the controlled attenuation parameter in patients with chronic hepatitis B
Hee Jun PARK ; Hyo Jeong KANG ; So Yeon KIM ; Seonghun YOON ; Seunghee BAEK ; In Hye SONG ; Hyeon Ji JANG ; Jong Keon JANG
Ultrasonography 2025;44(1):83-91
Purpose:
This study assessed the impact of hepatic fibrosis on the diagnostic performance of the controlled attenuation parameter (CAP) in quantifying hepatic steatosis in patients with chronic hepatitis B (CHB).
Methods:
CHB patients who underwent liver stiffness measurement (LSM) and CAP assessment using transient elastography before liver resection between 2019 and 2022 were retrospectively evaluated. Clinical data included body mass index (BMI) and laboratory parameters. The histologically determined hepatic fat fraction (HFF) and fibrosis stages were reviewed by pathologists blinded to clinical and radiologic data. The Pearson correlation coefficient between CAP and HFF was calculated. The diagnostic performance of CAP for significant hepatic steatosis (HFF ≥10%) was assessed using areas under the receiver operating curve (AUCs), stratified by fibrosis stages (F0-1 vs. F2-4). Factors significantly associated with CAP were determined by univariable and multivariable linear regression analyses.
Results:
Among 399 CHB patients (median age 59 years; 306 men), 16.3% showed significant steatosis. HFF ranged from 0% to 60%. Of these patients, 9.8%, 19.8%, 29.3%, and 41.1% had fibrosis stages F0-1, F2, F3, and F4, respectively. CAP positively correlated with HFF (r=0.445, P<0.001). The AUC of CAP for diagnosing significant steatosis was 0.786 (95% confidence interval [CI], 0.726 to 0.845) overall, and significantly lower in F2-4 (0.772; 95% CI, 0.708 to 0.836) than in F0-1 (0.924; 95% CI, 0.835 to 1.000) (P=0.006). Multivariable analysis showed that BMI (P<0.001) and HFF (P<0.001) significantly affected CAP, whereas LSM and fibrosis stages did not.
Conclusion
CAP evaluations of significant hepatic steatosis are less reliable in CHB patients with significant or more advanced (F2-4) than with no or mild (F0-1) fibrosis.
8.Increasing Very Low-Dose Edoxaban Prescription: Effectiveness and Safety Data of Korean AF Patients
JungMin CHOI ; So-Young YANG ; So-Ryoung LEE ; Min Soo CHO ; Kyung-Yeon LEE ; Hyo-Jeong AHN ; Soonil KWON ; Myung-Jin CHA ; Jun KIM ; Gi-Byoung NAM ; Kee-Joon CHOI ; Eue-Keun CHOI ; Seil OH ; Gregory Y. H. LIP
Korean Circulation Journal 2025;55(3):215-227
Background and Objectives:
Evidence remains limited on the real-world prescription of very low-dose oral anticoagulation among frail patients with atrial fibrillation (AF). We described the practice patterns, effectiveness, and safety of very low-dose edoxaban (15 mg once daily).
Methods:
Patients with AF prescribed edoxaban 15 mg once daily in 2 tertiary hospitals between 2016 and September 2022 were included. Baseline clinical characteristics and clinical outcomes of interest were thromboembolic and bleeding events.
Results:
A total of 674 patients were included (mean age 78.3±9.1, 49.7% aged ≥80 years, 49.3% women, median follow-up 1.0±1.2 years). Mean CHA 2 DS 2 -VASc score was 3.9±1.6, and the modified HAS-BLED score was 2.0±1.1. Between 2016 and 2022, the number of very lowdose edoxaban prescriptions increased. The main reasons for the prescription of very lowdose were low body weight (55.5% below 60 kg), anaemia (62.8%), chronic kidney disease (40.2%), active cancer (15.3%), concomitant anti-platelet use (26.7%), and prior major bleeding (19.7%). During a median follow-up duration of 8 (interquartile range 3–16) months, overall thromboembolic and bleeding events occurred in 16 (2.3%) and 88 (13.1%) patients, respectively. Compared to the expected event rates on the established risk scoring systems, patients receiving very low-dose edoxaban demonstrated a 61% reduction in ischemic stroke, a 68% reduction of ischemic stroke/transient ischemic attack/systemic embolism, whereas a 49% increase in major bleeding.
Conclusions
The prescription of very low-dose edoxaban was increased over time, attributable to various clinical factors. The use of very low-dose edoxaban reduced the expected risk of thromboembolic events.
9.Career paths and career choice factors of medical school graduates working in the Daejeon, Sejong, and Chungcheongnam-do region: a retrospective observational study
Korean Journal of Medical Education 2025;37(2):105-118
Purpose:
This study analyzed the career paths of medical school graduates in the Daejeon, Sejong, and Chungcheongnam-do (DSC) region of South Korea, focusing on career choice factors at each career path. The ultimate goal was to derive practical insights to improve career guidance in the medical field and enhance professionalism.
Methods:
Data were collected through in-depth interviews with 10 medical school graduates working in the DSC region. A semi-structured questionnaire was used to explore their career paths, and factors influencing their career decisions. The collected qualitative data were analyzed using the constant comparative method to identify themes and categories.
Results:
The study results categorized career stages into three phases: “entering medical school,” “choosing a specialty after graduation,” and “choosing a workplace after training.” Career choice factors were classified into “personal factors,” “social factors,” and “job and work environment factors.” The factors influencing career choices differed across each career path.
Conclusion
This study holds significance in its in-depth analysis of career choice factors across different career paths from a long-term perspective. The findings suggest that effective support for career decision-making in the medical field requires a tailored approach that considers the distinct needs and influencing factors at each career path.
10.Latest Insights into Long COVID Diagnosis and Treatment
Jun-Won SEO ; Seong Eun KIM ; Yoonjung KIM ; Eun Jung KIM ; Tark KIM ; Tae Hwa KIM ; So Hee LEE ; Eunjung LEE ; Jacob LEE ; Yu Bin SEO ; Young-Hoon JEONG ; Young Hee JUNG ; Yu Jung CHOI ; Joon Young SONG
Korean Journal of Medicine 2025;100(2):45-53
Long coronavirus disease (COVID) is a condition in which coronavirus disease 2019 (COVID-19) symptoms persist for over 3 months, and currently poses a global public health challenge. Due to varying manifestations and lack of standardized definitions, diagnostic methods, and treatments, comprehensive clinical guidelines are required. This review article, summarizing research and expert consensus up to June 2023, provides recommendations for diagnosis and long-term management of long COVID symptoms. It emphasizes thorough patient evaluation, including medical history, physical examinations, and tests, and advocates vaccination and antiviral treatments to reduce risk. Guidelines for long COVID will be updated as new knowledge emerges.

Result Analysis
Print
Save
E-mail