1.Causal effects of fluid intelligence on psychiatric disorders
Sunyeup KIM ; Gahyun KIM ; Minyoung KIM ; Kyung-Hun SUNG ; Seunghyup LEE ; Youngoh BAE ; Seung Won LEE
Precision and Future Medicine 2026;10(1):27-38
Purpose:
Fluid intelligence (FI), a core cognitive function involved in reasoning and problem-solving, has been linked to psychiatric outcomes in observational studies. However, causal inferences remain challenging due to confounding and reverse causation. This study aimed to investigate the causal effects of FI on 10 major psychiatric disorders using Mendelian randomization (MR).
Methods:
We performed a phenome-wide association study-based two-sample MR analysis to evaluate the effects of genetically proxied FI on 10 psychiatric disorders. Genome-wide association study summary statistics were obtained from large-scale European cohort studies. The inverse-variance-weighted method served as the primary analytical method, and complementary sensitivity analyses were conducted to assess pleiotropy and heterogeneity.
Results:
Higher FI was causally associated with a reduced risk of attention-deficit/hyperactivity disorder (ADHD) (odds ratio [OR], 0.72; P< 0.001), schizophrenia (OR, 0.69; P= 0.016), and post-traumatic stress disorder (PTSD) (OR, 0.93; P= 0.006). In contrast, FI was positively associated with an increased risk of autism spectrum disorder (ASD; OR, 1.43; P < 0.001) and anorexia nervosa (OR, 1.39; P= 0.005). No significant associations were observed for major depressive disorder, anxiety disorder, bipolar disorder, obsessive-compulsive disorder, or postpartum depression. Sensitivity analyses supported the robustness of these findings, with no evidence of directional pleiotropy or undue influence of individual single-nucleotide polymorphisms.
Conclusion
This study provides genetic evidence that higher FI exerts divergent causal effects across psychiatric disorders, protective in externalizing and stress-related conditions (ADHD, PTSD, and schizophrenia) but associated with an increased risk of neurodevelopmental and internalizing conditions (ASD and anorexia nervosa). These findings highlight the need for a nuanced understanding of cognitive capacity in psychiatric vulnerability and guide preventive strategies tailored to disorder-specific cognitive profiles.
2.Polyunsaturated Fatty Acids and Skin Cancer: Two-Sample Mendelian Randomization Study
Gahyun KIM ; Bo Ri KIM ; Kyungho PAIK ; Seon-Pil JIN ; Hyunsun PARK ; Woojae MYUNG ; Jin-Ku LEE ; Chong Won CHOI ; Jinho KIM
Annals of Dermatology 2025;37(6):363-376
Background:
Observational studies have suggested associations between dietary polyunsaturated fatty acids (PUFAs) and cancer risk; however, causal inference regarding skin cancer remains limited due to potential recall bias, confounding, and reverse causation.
Objective:
This study aimed to evaluate the causal association between genetically predicted circulating PUFA levels and the risk of skin cancers, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma.
Methods:
We conducted a 2-sample Mendelian randomization (MR) study using genome-wide association study summary statistics from the UK Biobank (PUFAs, n=115,006) and the FinnGen consortium (BCC, n=26,272; SCC, n=4,663; melanoma, n=5,753). Genetic instruments were derived for omega-3, docosahexaenoic acid, omega-6, linoleic acid, and the omega-6:3 ratio.Multiple MR methods—including inverse-variance weighted, MR-Egger, weighted median, weighted mode, and MR-PRESSO—were applied to test for consistency and assess pleiotropy and heterogeneity.
Results:
A higher genetically predicted linoleic acid to total fatty acid ratio was associated with a significantly lower risk of BCC and SCC. Conversely, higher genetically proxied serum omega-3 levels were associated with increased risks of BCC, SCC, and melanoma. The risk effect on SCC was attenuated upon exclusion of rs174528, a variant in the fatty acid desaturase 1 (FADS1) gene, suggesting a role for endogenous PUFA metabolism in carcinogenesis.
Conclusion
This MR analysis supports a causal role of circulating PUFAs in skin cancer development and highlights the importance of FADS-mediated endogenous PUFA metabolism. These findings provide novel insights into the genetic and metabolic underpinnings of skin cancer susceptibility.
3.A comparative analysis of canine Internal Medicine pancreatic lipase tests for diagnosing pancreatitis in dogs
Jin-Kyung KIM ; Sun Young HWANG ; Se Eun KIM ; Gahyun LEE ; Soungjin JI ; Jungho KIM ; Yongbaek KIM
Journal of Veterinary Science 2024;25(3):e48-
Objective:
Many qualitative and quantitative commercial cPL tests have been developed and used in veterinary clinics. This study aimed to compare three different methodologies SNAP cPL, Spec cPL, and Vcheck cPL tests to assess the concordance of these assays.
Methods:
Fifty serum samples were collected from 36 dogs with or without pancreatitis and subjected to SNAP cPL, Spec cPL, and Vcheck cPL tests. Agreement and correlation coefficients were calculated between the test results, and correlations were determined during the management of the patients.
Results:
The results of the three cPL assays were strongly correlated in 47/50 serum samples (94%). Cohen’s kappa analysis between the Spec cPL and Vcheck cPL showed near perfect agreement (κ = 0.960, p < 0.001), SNAP cPL and Vcheck cPL (κ = 0.920, p < 0.001), and Spec cPL and SNAP cPL (κ = 0.880, p < 0.001). The correlation coefficients (r) between data from Spec cPL and Vcheck cPL tests was calculated by Spearman’s correlation test (r = 0.958, p < 0.001).Furthermore, the patterns of change in serum cPL concentrations determined using Spec cPL and Vcheck cPL were significantly consistent during the monitoring period in 11 patients.
Conclusions
and Relevance: Our data illustrated that Spec cPL and Vcheck cPL tests are compatible for clinical use in the diagnosis and monitoring of canine pancreatitis.
4.Development of delayed thyroid stimulating hormone elevation in small-for-gestational-age infants: is a second screening needed?
Gahyun LEE ; So Yun PARK ; Jae Hyun PARK ; Seokjin KANG
Annals of Pediatric Endocrinology & Metabolism 2023;28(1):42-48
Purpose:
Recent reports indicate that small for gestational age (SGA) could be a risk factor for delayed thyroid stimulating hormone (dTSH) elevation in preterm infants. The development of dTSH elevation in SGA late-preterm infants with a gestational age of 34–36 weeks has been investigated in only a few studies.
Methods:
In the present retrospective study, 70 SGA infants and 86 sex- and gestational age-matched controls who presented with normal results on initial thyroid function testing were included.
Results:
SGA infants had a significantly higher prevalence of dTSH elevation (15.7% vs. 3.5%, P=0.009) compared with appropriate-for-gestational age infants. In SGA infants, the mean age at the time of dTSH was 24 days. Development of dTSH was associated with SGA and medical treatment with dopamine or furosemide. After adjusting for confounding factors, multiple logistic regression analysis showed SGA was a significant risk factor for the development of dTSH elevation (odds ratio, 23.2; 95% confidence interval, 2.27–236.91; P=0.008).
Conclusion
SGA infants may be at risk for dTSH and clinicians could consider a second thyroid screening test around the age of 1 month.
5.Embarrassed Radiofrequency Catheter Ablation of Supraventricular Tachycardia in Pectus Excavatum
The Ewha Medical Journal 2022;45(3):e6-
A 16-year-old patient with pectus excavatum visited our hospital because of palpitation. He underwent first Nuss operations at the age of 3. When he was 13 years old, the slow-fast type atrioventricular nodal reentrant tachycardia was documented during electrophysiology study. However, the catheter ablation was not conducted because of recurrent atrial fibrillation during procedure. At that time, second Nuss operation was performed due to progressive chest wall deformity. And then, atrioventricular nodal reentrant tachycardia was successfully treated by radiofrequency catheter ablation at the higher position than usual slow pathway zone under the modified fluoroscopic view with the cranial angle although distorted right atrial geometry and radiographic obstacle of Nuss operation bar. The concern about abnormal cardiac and electrical anatomy, and the accurate and modified procedure technique are essential in patients with pectus excavatum. (Ewha Med J 2022;45(3):e6)
6.Assessment of neovascularization during bone healing using contrast-enhanced ultrasonography in a canine tibial osteotomy model: a preliminary study
Sunghoon JEON ; Jaeyoung JANG ; Gahyun LEE ; Seungjo PARK ; Sang kwon LEE ; Hyunwook KIM ; Jihye CHOI
Journal of Veterinary Science 2020;21(1):e10-
Blood perfusion of skeletal muscle and callus was evaluated using contrast-enhanced ultrasonography (CEUS) in a canine osteotomy model to determine the applicability of CEUS in the assessment of neovascularization during fracture healing and to compare the vascular signals on CEUS between external skeletal fixation and cast-applied dogs. In 6 Beagle dogs, a simple transverse osteotomy was performed at the left tibial shaft and external skeletal fixation (n = 3) or a cast (n = 3) was applied. Radiography, power Doppler ultrasonography (power Doppler), and CEUS were performed until complete union was achieved. On CEUS, vascular changes were quantitatively evaluated by measuring peak intensity (PI) and time to PI in the soft tissue and callus and by counting the vascular signals. Vascular signals from the soft tissue were detected on power Doppler and CEUS on day 2. Significantly more vascular signals were detected by CEUS than by power Doppler. On CEUS, PI in the surrounding soft tissue was markedly increased after the fracture line appeared indistinctively changed on radiography in all dogs. In the cast-applied dogs, vascular signals from the periosteal and endosteal callus were detected on CEUS before mineralized callus was observed on radiography. CEUS was useful in assessing the vascularity of soft tissue and callus, particularly in indirect fracture healing, and provided indications of a normally healing fracture.
7.Assessment of neovascularization during bone healing using contrast-enhanced ultrasonography in a canine tibial osteotomy model: a preliminary study
Sunghoon JEON ; Jaeyoung JANG ; Gahyun LEE ; Seungjo PARK ; Sang kwon LEE ; Hyunwook KIM ; Jihye CHOI
Journal of Veterinary Science 2020;21(1):e10-
Blood perfusion of skeletal muscle and callus was evaluated using contrast-enhanced ultrasonography (CEUS) in a canine osteotomy model to determine the applicability of CEUS in the assessment of neovascularization during fracture healing and to compare the vascular signals on CEUS between external skeletal fixation and cast-applied dogs. In 6 Beagle dogs, a simple transverse osteotomy was performed at the left tibial shaft and external skeletal fixation (n = 3) or a cast (n = 3) was applied. Radiography, power Doppler ultrasonography (power Doppler), and CEUS were performed until complete union was achieved. On CEUS, vascular changes were quantitatively evaluated by measuring peak intensity (PI) and time to PI in the soft tissue and callus and by counting the vascular signals. Vascular signals from the soft tissue were detected on power Doppler and CEUS on day 2. Significantly more vascular signals were detected by CEUS than by power Doppler. On CEUS, PI in the surrounding soft tissue was markedly increased after the fracture line appeared indistinctively changed on radiography in all dogs. In the cast-applied dogs, vascular signals from the periosteal and endosteal callus were detected on CEUS before mineralized callus was observed on radiography. CEUS was useful in assessing the vascularity of soft tissue and callus, particularly in indirect fracture healing, and provided indications of a normally healing fracture.
9.Quantitative evaluation of renal parenchymal perfusion using contrast-enhanced ultrasonography in renal ischemia-reperfusion injury in dogs.
Gahyun LEE ; Sunghoon JEON ; Sang kwon LEE ; Byunggyu CHEON ; Sohyeon MOON ; Jun Gyu PARK ; Kyoung Oh CHO ; Jihye CHOI
Journal of Veterinary Science 2017;18(4):507-514
This study evaluated whether renal perfusion changes can be noninvasively estimated by using contrast-enhanced ultrasonography (CEUS) in renal ischemia-reperfusion injury and investigated the correlation between renal perfusion measured by CEUS and necrosis and apoptosis of renal tubular epithelial cells. In six dogs with experimentally induced renal ischemia-reperfusion injury, changes in time to peak intensity, peak intensity, and area under the curve were measured on CEUS. Peak intensity and area under the curve of the renal cortex began to decrease on day 1 (about 20% lower than baseline) and reached the lowest levels (about 50% of baseline) on day 4. They then gradually increased until day 10, at which time peak intensity was about 87% and area under the curve was about 95% of baseline; neither fully recovered. Both parameters were strongly correlated with the necrosis scores on histopathologic examination on day 4 (r = −0.810 of peak intensity and r = −0.886 of area under the curve). CEUS allowed quantitative evaluation of perfusion changes in acute renal ischemia-reperfusion injury, and CEUS results were correlated with renal tubular damage on histopathologic examination. Thus, CEUS could be a noninvasive, quantitative diagnostic method for determining progress of renal ischemia-reperfusion injury.
Animals
;
Apoptosis
;
Dogs*
;
Epithelial Cells
;
Evaluation Studies as Topic*
;
Methods
;
Necrosis
;
Perfusion*
;
Reperfusion Injury*
;
Ultrasonography*
10.Clinical usefulness of post-operative 18F-fluorodeoxyglucose positron emission tomography-computed tomography in canine hemangiosarcoma.
Gahyun LEE ; Seong Young KWON ; Kyuyeol SON ; Seungjo PARK ; Ju Hwan LEE ; Kyoung Oh CHO ; Jung Joon MIN ; Jihye CHOI
Journal of Veterinary Science 2016;17(2):257-260
This report describes the usefulness of positron emission tomography-computed tomography (PET-CT) for evaluating recurrent or residual tumors following surgery. CT and 18F-fluorodeoxyglucose PET-CT were pre- and post-operatively applied to multiple masses in a dog with hemangiosarcoma. The distinction between the left subcutaneous mass and the peritoneum was clarified on pre-operative CT examination, and malignancy was suspected based on PET-CT. A recurrent or residual tumor in the left subcutaneous region was suspected on post-operative PET-CT, and confirmed through histopathologic examination.
Animals
;
Dogs
;
Electrons*
;
Hemangiosarcoma*
;
Neoplasm, Residual
;
Peritoneum

Result Analysis
Print
Save
E-mail