1.Alteration in gut microbiota after colonoscopy: proposed mechanisms and the role of probiotic interventions
Hyeong Ho JO ; Moon Young LEE ; Se Eun HA ; Dong Han YEOM ; Yong Sung KIM
Clinical Endoscopy 2025;58(1):25-39
Colonoscopy, a widely used procedure for diagnosing and treating colonic diseases, induces transient gastrointestinal symptoms and alterations in the gut microbiota. This review comprehensively examines the evidence on alterations in the gut microbiota following colonoscopy and their possible mechanisms. Factors such as rapid colonic evacuation, increased osmolality, and mucus thinning caused by bowel preparation and exposure to oxygen during the procedure contribute to these alterations. Typically, the alterations revert to the baseline within a short time. However, their long-term implications remain unclear, necessitating further investigation. Split-dose bowel preparation and CO2 insufflation during the procedure result in fewer alterations in the gut microbiota. Probiotic administration immediately after colonoscopy shows promise in reducing alterations and gastrointestinal symptoms. However, the widespread use of probiotics remains controversial due to the transient nature of both the symptoms and gut microbial alterations following a colonoscopy. Probiotics may offer greater benefits to individuals with preexisting gastrointestinal symptoms. Thus, probiotic administration may be a viable option for selected patients.
2.Alteration in gut microbiota after colonoscopy: proposed mechanisms and the role of probiotic interventions
Hyeong Ho JO ; Moon Young LEE ; Se Eun HA ; Dong Han YEOM ; Yong Sung KIM
Clinical Endoscopy 2025;58(1):25-39
Colonoscopy, a widely used procedure for diagnosing and treating colonic diseases, induces transient gastrointestinal symptoms and alterations in the gut microbiota. This review comprehensively examines the evidence on alterations in the gut microbiota following colonoscopy and their possible mechanisms. Factors such as rapid colonic evacuation, increased osmolality, and mucus thinning caused by bowel preparation and exposure to oxygen during the procedure contribute to these alterations. Typically, the alterations revert to the baseline within a short time. However, their long-term implications remain unclear, necessitating further investigation. Split-dose bowel preparation and CO2 insufflation during the procedure result in fewer alterations in the gut microbiota. Probiotic administration immediately after colonoscopy shows promise in reducing alterations and gastrointestinal symptoms. However, the widespread use of probiotics remains controversial due to the transient nature of both the symptoms and gut microbial alterations following a colonoscopy. Probiotics may offer greater benefits to individuals with preexisting gastrointestinal symptoms. Thus, probiotic administration may be a viable option for selected patients.
3.Idiopathic Orbital Myositis Presenting with Upper Eyelid Retraction: A Case Series
Yong-Ha JO ; Min Kyu YANG ; Seong Jung HA ; Ho-Seok SA
Journal of the Korean Ophthalmological Society 2025;66(3):151-157
Purpose:
Although upper eyelid retraction is commonly associated with thyroid eye disease, its etiology remains unclear. This study evaluated the clinical features and treatment outcomes of patients with upper eyelid retraction caused by idiopathic orbital myositis (IOM).
Methods:
We conducted a retrospective analysis of the medical records of patients who presented with unilateral upper eyelid retraction. IOM was diagnosed based on normal thyroid function tests (TFT), including thyroid-stimulating immunoglobulin (TSI). Orbital imaging demonstrated contrast-enhanced enlargement of the superior rectus-levator palpebrae superioris complex (SR-LC). Pre- and post-systemic steroid treatment, margin-reflex distance 1 (MRD1), MRD1 difference between affected and unaffected eyes, exophthalmos, and diplopia were assessed.
Results:
In total, five patients (male: 4, female: 1) with a median age of 36.4 years were diagnosed with IOM. Three patients presented with diplopia on upgaze and supraduction limitation. Orbital imaging revealed levator palpebrae superioris muscle enlargement with distinct borders and homogeneous contrast enhancement. All cases with superior rectus enlargement demonstrated tendon involvement. The median duration from symptom onset to treatment initiation was 2.2 months. Four patients received oral prednisolone, whereas one received intravenous methylprednisolone. Although no significant improvements were observed in MRD1, MRD1 difference, or exophthalmos post-treatment, diplopia resolved in all three patients.
Conclusions
IOM can present with upper eyelid retraction, emphasizing the importance of differentiating it from thyroid eye disease. TFT, including TSIs, and orbital imaging are essential diagnostic tools. These findings indicate that systemic corticosteroids can effectively manage diplopia associated with IOM, emphasizing the potential benefit of early and aggressive treatment.
4.Idiopathic Orbital Myositis Presenting with Upper Eyelid Retraction: A Case Series
Yong-Ha JO ; Min Kyu YANG ; Seong Jung HA ; Ho-Seok SA
Journal of the Korean Ophthalmological Society 2025;66(3):151-157
Purpose:
Although upper eyelid retraction is commonly associated with thyroid eye disease, its etiology remains unclear. This study evaluated the clinical features and treatment outcomes of patients with upper eyelid retraction caused by idiopathic orbital myositis (IOM).
Methods:
We conducted a retrospective analysis of the medical records of patients who presented with unilateral upper eyelid retraction. IOM was diagnosed based on normal thyroid function tests (TFT), including thyroid-stimulating immunoglobulin (TSI). Orbital imaging demonstrated contrast-enhanced enlargement of the superior rectus-levator palpebrae superioris complex (SR-LC). Pre- and post-systemic steroid treatment, margin-reflex distance 1 (MRD1), MRD1 difference between affected and unaffected eyes, exophthalmos, and diplopia were assessed.
Results:
In total, five patients (male: 4, female: 1) with a median age of 36.4 years were diagnosed with IOM. Three patients presented with diplopia on upgaze and supraduction limitation. Orbital imaging revealed levator palpebrae superioris muscle enlargement with distinct borders and homogeneous contrast enhancement. All cases with superior rectus enlargement demonstrated tendon involvement. The median duration from symptom onset to treatment initiation was 2.2 months. Four patients received oral prednisolone, whereas one received intravenous methylprednisolone. Although no significant improvements were observed in MRD1, MRD1 difference, or exophthalmos post-treatment, diplopia resolved in all three patients.
Conclusions
IOM can present with upper eyelid retraction, emphasizing the importance of differentiating it from thyroid eye disease. TFT, including TSIs, and orbital imaging are essential diagnostic tools. These findings indicate that systemic corticosteroids can effectively manage diplopia associated with IOM, emphasizing the potential benefit of early and aggressive treatment.
5.Alteration in gut microbiota after colonoscopy: proposed mechanisms and the role of probiotic interventions
Hyeong Ho JO ; Moon Young LEE ; Se Eun HA ; Dong Han YEOM ; Yong Sung KIM
Clinical Endoscopy 2025;58(1):25-39
Colonoscopy, a widely used procedure for diagnosing and treating colonic diseases, induces transient gastrointestinal symptoms and alterations in the gut microbiota. This review comprehensively examines the evidence on alterations in the gut microbiota following colonoscopy and their possible mechanisms. Factors such as rapid colonic evacuation, increased osmolality, and mucus thinning caused by bowel preparation and exposure to oxygen during the procedure contribute to these alterations. Typically, the alterations revert to the baseline within a short time. However, their long-term implications remain unclear, necessitating further investigation. Split-dose bowel preparation and CO2 insufflation during the procedure result in fewer alterations in the gut microbiota. Probiotic administration immediately after colonoscopy shows promise in reducing alterations and gastrointestinal symptoms. However, the widespread use of probiotics remains controversial due to the transient nature of both the symptoms and gut microbial alterations following a colonoscopy. Probiotics may offer greater benefits to individuals with preexisting gastrointestinal symptoms. Thus, probiotic administration may be a viable option for selected patients.
6.Idiopathic Orbital Myositis Presenting with Upper Eyelid Retraction: A Case Series
Yong-Ha JO ; Min Kyu YANG ; Seong Jung HA ; Ho-Seok SA
Journal of the Korean Ophthalmological Society 2025;66(3):151-157
Purpose:
Although upper eyelid retraction is commonly associated with thyroid eye disease, its etiology remains unclear. This study evaluated the clinical features and treatment outcomes of patients with upper eyelid retraction caused by idiopathic orbital myositis (IOM).
Methods:
We conducted a retrospective analysis of the medical records of patients who presented with unilateral upper eyelid retraction. IOM was diagnosed based on normal thyroid function tests (TFT), including thyroid-stimulating immunoglobulin (TSI). Orbital imaging demonstrated contrast-enhanced enlargement of the superior rectus-levator palpebrae superioris complex (SR-LC). Pre- and post-systemic steroid treatment, margin-reflex distance 1 (MRD1), MRD1 difference between affected and unaffected eyes, exophthalmos, and diplopia were assessed.
Results:
In total, five patients (male: 4, female: 1) with a median age of 36.4 years were diagnosed with IOM. Three patients presented with diplopia on upgaze and supraduction limitation. Orbital imaging revealed levator palpebrae superioris muscle enlargement with distinct borders and homogeneous contrast enhancement. All cases with superior rectus enlargement demonstrated tendon involvement. The median duration from symptom onset to treatment initiation was 2.2 months. Four patients received oral prednisolone, whereas one received intravenous methylprednisolone. Although no significant improvements were observed in MRD1, MRD1 difference, or exophthalmos post-treatment, diplopia resolved in all three patients.
Conclusions
IOM can present with upper eyelid retraction, emphasizing the importance of differentiating it from thyroid eye disease. TFT, including TSIs, and orbital imaging are essential diagnostic tools. These findings indicate that systemic corticosteroids can effectively manage diplopia associated with IOM, emphasizing the potential benefit of early and aggressive treatment.
7.Chromosomal Rearrangements in 1,787 Cases of Acute Leukemia in Korea over 15 Years
DongGeun SON ; Ho Cheol JANG ; Young Eun LEE ; Yong Jun CHOI ; Joo Heon PARK ; Ha Jin LIM ; Hyun-Jung CHOI ; Hee Jo BAEK ; Hoon KOOK ; Mihee KIM ; Ga-Young SONG ; Seo-Yeon AHN ; Sung-Hoon JUNG ; Deok-Hwan YANG ; Je-Jung LEE ; Hyeonug-Joon KIM ; Jae-Sook AHN ; Myung-Geun SHIN
Annals of Laboratory Medicine 2025;45(4):391-398
Background:
Chromosomal alterations serve as diagnostic and prognostic markers in acute leukemia. Given the evolving landscape of chromosomal abnormalities in acute leukemia, we previously studied these over two periods. In this study, we investigated the frequency of these abnormalities and clinical trends in acute leukemia in Korea across three time periods.
Methods:
We retrospectively analyzed data from 1,787 patients with acute leukemia (319 children and 1,468 adults) diagnosed between 2006 and 2020. Conventional cytogenetics, FISH, and multiplex quantitative PCR were used for analysis. The patient groups were divided according to the following three study periods: 2006–2009 (I), 2010–2015 (II), and 2016–2020 (III).
Results:
Chromosomal aberrations were detected in 92% of patients. The PML::RARA translocation was the most frequent. Over the 15-yr period, chromosomal aberrations showed minimal changes, with specific fusion transcripts being common among patients.ALL was more prevalent in children than in adults and correlated significantly with the ETV6::RUNX1 and RUNX1::RUNX1T1 aberrations. The incidence of ALL increased during the three periods, with PML::RARA remaining common.
Conclusions
The frequency of chromosomal abnormalities in acute leukemia has changed subtly over time. Notably, the age of onset of adult AML has continuously increased. Our results may help in establishing diagnoses and clinical treatment strategies and developing various molecular diagnostic platforms.
8.Association Between Low Anti-spike Antibody Levels After the Third Dose of SARS-CoV-2 Vaccination and Hospitalization due to Symptomatic Breakthrough Infection in Kidney Transplant Recipients
Ahram HAN ; Sangil MIN ; Eun-Ah JO ; Hajeong LEE ; Yong Chul KIM ; Seung Seok HAN ; Hee Gyung KANG ; Yo Han AHN ; Inseong OH ; Eun Young SONG ; Jongwon HA
Annals of Laboratory Medicine 2024;44(1):64-73
Background:
Whether anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody levels post-third coronavirus disease (COVID-19) vaccination correlate with worse outcomes due to breakthrough infection is unclear. We evaluated the association between anti-SARS-CoV-2 antibody levels and symptomatic breakthrough infection or hospitalization during the Omicron surge in kidney transplant recipients.
Methods:
In total, 287 kidney transplant recipients expected to receive a third vaccination were enrolled between November 2021 and February 2022. The Abbott SARS-CoV-2 IgG II Quant test (Abbott, Chicago, IL, USA) was performed within three weeks before and four weeks after the third vaccination. The incidence of symptomatic breakthrough infection and hospitalization from two weeks to four months post-third vaccination was recorded.
Results:
After the third vaccination, the seropositive rate and median antibody titer of the 287 patients increased from 57.1% to 82.2% and from 71.7 (interquartile range [IQR] 7.2– 402.8) to 1,612.1 (IQR 153.9–5,489.1) AU/mL, respectively. Sixty-four (22.3%) patients had symptomatic breakthrough infections, of whom 12 required hospitalization. Lower anti-receptor-binding domain (RBD) IgG levels ( < 400 AU/mL) post-third vaccination were a risk factor for symptomatic breakthrough infection (hazard ratio [HR] = 3.46, P < 0.001).Anti-RBD IgG levels < 200 AU/mL were a critical risk factor for hospitalization (HR = 36.4, P = 0.007).
Conclusions
Low anti-spike IgG levels after third vaccination in kidney transplant recipients were associated with symptomatic breakthrough infection and, particularly, with hospitalization during the Omicron surge. These data can be used to identify patients requiring additional protective measures, such as passive immunization using monoclonal antibodies.
9.Smoking-attributable Mortality in Korea, 2020: A Meta-analysis of 4 Databases
Eunsil CHEON ; Yeun Soo YANG ; Suyoung JO ; Jieun HWANG ; Keum Ji JUNG ; Sunmi LEE ; Seong Yong PARK ; Kyoungin NA ; Soyeon KIM ; Sun Ha JEE ; Sung-il CHO
Journal of Preventive Medicine and Public Health 2024;57(4):327-338
Objectives:
Estimating the number of deaths caused by smoking is crucial for developing and evaluating tobacco control and smoking cessation policies. This study aimed to determine smoking-attributable mortality (SAM) in Korea in 2020.
Methods:
Four large-scale cohorts from Korea were analyzed. A Cox proportional-hazards model was used to determine the hazard ratios (HRs) of smoking-related death. By conducting a meta-analysis of these HRs, the pooled HRs of smoking-related death for 41 diseases were estimated. Population-attributable fractions (PAFs) were calculated based on the smoking prevalence for 1995 in conjunction with the pooled HRs. Subsequently, SAM was derived using the PAF and the number of deaths recorded for each disease in 2020.
Results:
The pooled HR for all-cause mortality attributable to smoking was 1.73 for current men smokers (95% confidence interval [CI], 1.53 to 1.95) and 1.63 for current women smokers (95% CI, 1.37 to 1.94). Smoking accounted for 33.2% of all-cause deaths in men and 4.6% in women. Additionally, it was a factor in 71.8% of men lung cancer deaths and 11.9% of women lung cancer deaths. In 2020, smoking was responsible for 53 930 men deaths and 6283 women deaths, totaling 60 213 deaths.
Conclusions
Cigarette smoking was responsible for a significant number of deaths in Korea in 2020. Monitoring the impact and societal burden of smoking is essential for effective tobacco control and harm prevention policies.
10.Allergen sensitization trajectories in children with respiratory and allergic diseases
So Won JO ; Soyoung JEON ; Hye Sun LEE ; Ha Min KIM ; Yoon Young NO ; Mi Reu PARK ; Jae Hwa JUNG ; Soo Yeon KIM ; Jong Duck KIM ; Min Jung KIM ; Yong Ju LEE ; Kyung Won KIM ; Myung Hyun SOHN ; Yoon Hee KIM
Allergy, Asthma & Respiratory Disease 2023;11(1):34-42
Purpose:
There is a lack of a report about the trajectories of allergen sensitization, although it is important to understand the change of allergen sensitization to manage allergic disease. This study aimed to analyze the change and trajectories of allergen sensitization in children with respiratory and allergic diseases.
Methods:
From 2006 to 2020, children with respiratory and allergic diseases or screened for allergic sensitization were evaluated. We visualized the alterations and the trajectories of allergen sensitization using stacked area graphs, box plots, and Sankey diagrams.
Results:
A total of 2,804 subjects were included, and allergic rhino-conjunctivitis was diagnosed in 1,931 children (68.9%). The mean age for the first test was 4.1 years, and that for the second test was 6.5 years. Children sensitized to class 1 food allergen before age 5 showed sensitizations more for other allergens and at a younger age after age 5 than children who were not. The atopic tendency continued once it had been obtained before the early school age in the persistence or the new development of sensitization.
Conclusion
Allergen sensitization has changed over time and has shown different patterns according to age. Its trajectory has taken a wide variety of courses in children with respiratory and allergic diseases until the early school age. These changes reflect the allergic diseases and socio-environmental characteristics of children and adolescents.

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