1.Prevalence and molecular characteristics of β-lactam resistance in non-typeable Haemophilus influenzae isolates in Korea
Eun-Young KIM ; Yeon Chan CHOI ; Hyeon Jin CHOI ; Si Hyun KIM ; Jihyun CHO ; Seok Hoon JEONG ; Dokyun KIM ; Hyun Soo KIM ; Soo Hyun KIM ; Young Ah KIM ; Young Ree KIM ; Nam Hee RYOO ; Jong Hee SHIN ; Kyeong Seob SHIN ; Young UH ; Jeong Hwan SHIN
Annals of Clinical Microbiology 2025;28(4):23-
Background:
Haemophilus influenzae is the causative pathogen for various infectious diseases, such as respiratory infections, otitis media, sinusitis, and meningitis. This study aimed to investigate the prevalence and molecular characteristics of β-lactam resistance in non-typeable H. influenzae isolates in South Korea.
Methods:
In total, 115 non-duplicated H. influenzae isolates were included in this study.Bacterial identification and serotyping were performed using matrix assisted laser desorption ionization-time of flight mass spectrometry and polymerase chain reaction (PCR) of bexA, respectively. Antimicrobial susceptibility was tested using the broth microdilution method.The production of β-lactamase was determined using nitrocefin disks. The presence of blaTEM and blaROB was confirmed using PCR. ftsI was analyzed to identify amino acid mutations in penicillin-binding protein (PBP) 3.
Results:
Resistance rates to ampicillin, amoxicillin–clavulanate, and cefuroxime were 67.8%, 13.9%, and 32.2%, respectively. None of the isolates were resistant to cefotaxime or ceftriaxone. Among 78 ampicillin-resistant isolates, 71 were β-lactamase-producing ampicillinresistant (BLPAR), and 7 were β-lactamase-non-producing ampicillin-resistant. All BLPAR isolates carried blaTEM, and none carried blaROB. Among 16 amoxicillin–clavulanate-resistant isolates, 15 β-lactamase producers harbored blaTEM. Four to 7 PBP3 mutations per isolate were detected in all 16 non-β-lactamase-producing ampicillin-resistant or cephalosporinresistant isolates.
Conclusion
Beta-lactam resistance in non-typeable H. influenzae isolates is highly prevalent in South Korea, primarily because of blaTEM and various PBP3 mutations. Therefore, continuous monitoring of antimicrobial resistance rates and mechanisms in non-typeable H.influenzae is necessary.
2.Current status of treatment for esophagojejunostomy leakage after total gastrectomy in patients with gastric cancer: a multicenter retrospective study in Korea
Min-Chan KIM ; Mi Ran JUNG ; Jeong Ju NOH ; Sunghwa KANG ; Jae Hun CHUNG ; Ji-Ho PARK ; Tae-Han KIM ; Jae Kyun PARK ; Yoonhong KIM ; Sang Hyuk SEO ; Sung Eun KIM ; Oh Kyung KWON ; Ji Yeon PARK ; Ki Bum PARK ; Sun-Hwi HWANG ; SI-Hak LEE ; Young-Joon LEE ; Sang-Ho JEONG ; Tae-Yong JEON ; Dae Hwan KIM ; Chang In CHOI ; Ki Young YOON ; Kyung Won SEO ; Ki Hyun KIM ; Sang Hoon OH ; Kwang Hee KIM
Journal of Minimally Invasive Surgery 2025;28(4):184-192
Purpose:
Esophagojejunostomy leakage (EJL) remains one of the most critical complications following total gastrectomy for gastric cancer. This study aimed to evaluate the evolving therapeutic approaches and clinical outcomes of EJL using data from a large-scale multicenter retrospective cohort.
Methods:
Among 6,577 patients who underwent total gastrectomy or proximal gastrectomy with double tract reconstruction at nine institutions from 2003 to 2024, 196 (3.0%) developed EJL. Of these, 162 patients with comprehensive clinical data were included in the final analysis. The study examined treatment modalities, changes in management over time, patient characteristics, surgical variables, and clinical outcomes. Four groups were defined according to treatment approach: conservative, endoscopic, reoperation, and multimodal (combined) therapy.
Results:
Endoscopic therapy was first introduced in 2011 and has progressively supplanted reoperation, now comprising 32.5% of cases. The average time to EJL diagnosis was 8.4 days after surgery. Overall in-hospital mortality was 6.1% (10/162). When conservative management was excluded, endoscopic treatment demonstrated the highest rate of therapeutic success (94.3%, p = 0.004). Both the duration until diet resumption and length of hospital stay were notably reduced in the endoscopic and conservative groups compared with reoperation and multimodal therapy (p < 0.001). Moreover, although the highest post-leakage hospitalization costs were observed with multimodal treatment (p < 0.001), overall hospitalization expenses were significantly lower for patients managed conservatively or with endoscopic intervention (p < 0.001).
Conclusion
Over the past two decades, management of EJL has shifted toward endoscopic approaches. Endoscopic therapies yield superior clinical outcomes and should be considered a primary option for appropriate candidates.
3.Catalpa bignonioides extract improves exercise performance through regulation of growth and metabolism in skeletal muscles
Hoibin Jeong ; Dong-joo Lee ; Sung-Pil Kwon ; SeonJu Park ; Song-Rae Kim ; Seung Hyun Kim ; Jae-Il Park ; Deug-chan Lee ; Kyung-Min Choi ; WonWoo Lee ; Ji-Won Park ; Bohyun Yun ; Su-Hyeon Cho ; Kil-Nam Kim
Asian Pacific Journal of Tropical Biomedicine 2024;14(2):47-54
Objective: To evaluate the effects of Catalpa bignonioides fruit extract on the promotion of muscle growth and muscular capacity in vitro and in vivo. Methods: Cell viability was measured using the 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide assay. Cell proliferation was assessed using a 5-bromo-2’-deoxyuridine (BrdU) assay kit. Western blot analysis was performed to determine the protein expressions of related factors. The effects of Catalpa bignonioides extract were investigated in mice using the treadmill exhaustion test and whole-limb grip strength assay. Chemical composition analysis was performed using high-performance liquid chromatography (HPLC). Results: Catalpa bignonioides extract increased the proliferation of C2C12 mouse myoblasts by activating the Akt/mTOR signaling pathway. It also induced metabolic changes, increasing the number of mitochondria and glucose metabolism by phosphorylating adenosine monophosphate-activated protein kinase. In an in vivo study, the extract-treated mice showed improved motor abilities, such as muscular endurance and grip strength. Additionally, HPLC analysis showed that vanillic acid may be the main component of the Catalpa bignonioides extract that enhanced muscle strength. Conclusions: Catalpa bignonioides improves exercise performance through regulation of growth and metabolism in skeletal muscles, suggesting its potential as an effective natural agent for improving muscular strength.
4.Presenteeism in Agricultural, Forestry and Fishing Workers:Based on the 6th Korean Working Conditions Survey
Sang-Hee HONG ; Eun-Chul JANG ; Soon-Chan KWON ; Hwa-Young LEE ; Myoung-Je SONG ; Jong-Sun KIM ; Mid-Eum MOON ; Sang-Hyeon KIM ; Ji-Suk YUN ; Young-Sun MIN
Journal of Agricultural Medicine & Community Health 2024;49(1):1-12
Objectives:
Presenteeism is known to be a much more economically damaging social cost than disease rest while going to work despite physical pain. Since COVID-19, social discussions on the sickness benefit have been taking place as a countermeasure against presenteeism, and in particular, farmers and fishermen do not have an institutional mechanism for livelihood support when a disease other than work occurs. This study attempted to examine the relationship between agricultural, fishing, and forestry workers and presenteeism using the 6th Korean Work Conditions Survey.
Methods:
From October 2020 to January 2021, data from the 6th working conditions survey conducted on 17 cities and provinces in Korea were used, and a total of 34,981 people were studied. Control variables were gender, age, self-health assessment, education level, night work, shift work, monthly income, occupation, working hours per week, and employment status.
Results:
As a result of the analysis, farmers and fishermen showed the characteristics of the self-employed and the elderly, and as a result of the regression analysis, when farmers and fishermen analyzed the relationship with presenteeism tendency compared to other industry workers, farmers and fishermen increased by 23% compared to other industry groups.
Conclusion
This study is significant in that it has representation by utilizing the 6th working conditions survey and objectively suggests the need for a sickness benefit for farmers and fishermen who may be overlooked in the sickness benefit.
5.Phenolic Compounds Isolated from Juncus decipiens and Their Effects on Osteoblast Differentiation in the Mouse Mesenchymal Stem Cell Line C3H10T1/2
Chan Hee CHO ; Si Hyeon CHAE ; Seon Hee KIM ; Ki Hyun KIM
Natural Product Sciences 2024;30(2):135-142
As part of our current projects to discover biologically active compounds from natural sources, we conducted a phytochemical investigation of Juncus decipiens, a species generally distributed throughout Korea. J. decipiens has been used in traditional Chinese medicine to control diuresis for strangury and clear out heart fire. The phytochemical investigation of the EtOH extract of J. decipiens led to the isolation of five phenolic compounds (1–5) via semi-preparative HPLC purification. The chemical structures of the isolated compounds were identified as isosaponarin (1), isovitexin 7,2′′-di-O-glucoside (2), 4-O-feruloylquinic acid (3), 5-O-feruloylquinic acid (4), and 3-O-caffeoylquinic acid (5) based on comparisons of their spectroscopic and physical properties with those reported in previous studies. Notably, this is the first report of the presence of compounds (1–4) in J. decipiens. Then, compounds 1–5 were tested to determine their effects on osteogenesis and adipogenesis in the mouse mesenchymal stem cell line C3H10T1/2. We found that quinic acid derivatives (3–5) promoted the osteogenic differentiation of stem cells. These findings demonstrate that the bioactive quinic acid derivatives might be effective for the treatment of menopause-associated syndromes, such as osteoporosis, as the isolated compounds were shown to promote osteogenesis of stem cells.
6.Tivozanib-induced activation of the mitochondrial apoptotic pathway and suppression of epithelial-to-mesenchymal transition in oral squamous cell carcinoma
Nak-Eun CHOI ; Si-Chan PARK ; In-Ryoung KIM
The Korean Journal of Physiology and Pharmacology 2024;28(3):197-207
The potential of tivozanib as a treatment for oral squamous cell carcinoma (OSCC) was explored in this study. We investigated the effects of tivozanib on OSCC using the Ca9-22 and CAL27 cell lines. OSCC is a highly prevalent cancer type with a significant risk of lymphatic metastasis and recurrence, which necessitates the development of innovative treatment approaches. Tivozanib, a vascular endothelial growth factor receptor inhibitor, has shown efficacy in inhibiting neovascularization in various cancer types but has not been thoroughly studied in OSCC. Our comprehensive assessment revealed that tivozanib effectively inhibited OSCC cells. This was accompanied by the suppression of Bcl-2, a reduction in matrix metalloproteinase levels, and the induction of intrinsic pathway-mediated apoptosis. Furthermore, tivozanib contributed to epithelial-to-mesenchymal transition (EMT) inhibition by increasing E-cadherin levels while decreasing N-cadherin levels. These findings highlight the substantial anticancer potential of tivozanib in OSCC and thus its promise as a therapeutic option. Beyond reducing cell viability and inducing apoptosis, the capacity of tivozanib to inhibit EMT and modulate key proteins presents the possibility of a paradigm shift in OSCC treatment.
7.Presenteeism in Agricultural, Forestry and Fishing Workers:Based on the 6th Korean Working Conditions Survey
Sang-Hee HONG ; Eun-Chul JANG ; Soon-Chan KWON ; Hwa-Young LEE ; Myoung-Je SONG ; Jong-Sun KIM ; Mid-Eum MOON ; Sang-Hyeon KIM ; Ji-Suk YUN ; Young-Sun MIN
Journal of Agricultural Medicine & Community Health 2024;49(1):1-12
Objectives:
Presenteeism is known to be a much more economically damaging social cost than disease rest while going to work despite physical pain. Since COVID-19, social discussions on the sickness benefit have been taking place as a countermeasure against presenteeism, and in particular, farmers and fishermen do not have an institutional mechanism for livelihood support when a disease other than work occurs. This study attempted to examine the relationship between agricultural, fishing, and forestry workers and presenteeism using the 6th Korean Work Conditions Survey.
Methods:
From October 2020 to January 2021, data from the 6th working conditions survey conducted on 17 cities and provinces in Korea were used, and a total of 34,981 people were studied. Control variables were gender, age, self-health assessment, education level, night work, shift work, monthly income, occupation, working hours per week, and employment status.
Results:
As a result of the analysis, farmers and fishermen showed the characteristics of the self-employed and the elderly, and as a result of the regression analysis, when farmers and fishermen analyzed the relationship with presenteeism tendency compared to other industry workers, farmers and fishermen increased by 23% compared to other industry groups.
Conclusion
This study is significant in that it has representation by utilizing the 6th working conditions survey and objectively suggests the need for a sickness benefit for farmers and fishermen who may be overlooked in the sickness benefit.
8.Presenteeism in Agricultural, Forestry and Fishing Workers:Based on the 6th Korean Working Conditions Survey
Sang-Hee HONG ; Eun-Chul JANG ; Soon-Chan KWON ; Hwa-Young LEE ; Myoung-Je SONG ; Jong-Sun KIM ; Mid-Eum MOON ; Sang-Hyeon KIM ; Ji-Suk YUN ; Young-Sun MIN
Journal of Agricultural Medicine & Community Health 2024;49(1):1-12
Objectives:
Presenteeism is known to be a much more economically damaging social cost than disease rest while going to work despite physical pain. Since COVID-19, social discussions on the sickness benefit have been taking place as a countermeasure against presenteeism, and in particular, farmers and fishermen do not have an institutional mechanism for livelihood support when a disease other than work occurs. This study attempted to examine the relationship between agricultural, fishing, and forestry workers and presenteeism using the 6th Korean Work Conditions Survey.
Methods:
From October 2020 to January 2021, data from the 6th working conditions survey conducted on 17 cities and provinces in Korea were used, and a total of 34,981 people were studied. Control variables were gender, age, self-health assessment, education level, night work, shift work, monthly income, occupation, working hours per week, and employment status.
Results:
As a result of the analysis, farmers and fishermen showed the characteristics of the self-employed and the elderly, and as a result of the regression analysis, when farmers and fishermen analyzed the relationship with presenteeism tendency compared to other industry workers, farmers and fishermen increased by 23% compared to other industry groups.
Conclusion
This study is significant in that it has representation by utilizing the 6th working conditions survey and objectively suggests the need for a sickness benefit for farmers and fishermen who may be overlooked in the sickness benefit.
9.A Phase II Trial of S-1 and Oxaliplatin in Patients with Metastatic Breast Cancer Previously Treated with Anthracycline and Taxane (KCSG-BR07-03)
Dae-Won LEE ; Bhumsuk KEAM ; Keun Seok LEE ; Jin-Hee AHN ; Joohyuk SOHN ; Jin Seok AHN ; Moon Hee LEE ; Jee Hyun KIM ; Kyung Eun LEE ; Hyo Jung KIM ; Si-Young KIM ; Yeon Hee PARK ; Chan-Young OCK ; Kyung-Hun LEE ; Sae-Won HAN ; Sung-Bae KIM ; Young Hyuck IM ; Hyun Cheol CHUNG ; Do-Youn OH ; Seock-Ah IM
Cancer Research and Treatment 2023;55(2):523-530
Purpose:
This single-arm phase II trial investigate the efficacy and safety of S-1 plus oxaliplatin (SOX) in patients with metastatic breast cancer.
Materials and Methods:
Patients with metastatic breast cancer previously treated with anthracyclines and taxanes were enrolled. Patients received S-1 (40-60 mg depending on patient’s body surface area, twice a day, day 1-14) and oxaliplatin (130 mg/m2, day 1) in 3 weeks cycle until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumor 1.1. Secondary endpoints included time-to-progression (TTP), duration-of-response (DoR), overall survival (OS), and adverse events.
Results:
A total of 87 patients were enrolled from 11 institutions in Korea. Hormone receptor was positive in 54 (62.1%) patients and six (6.9%) had human epidermal growth factor receptor 2–positive disease. Forty-eight patients (85.1%) had visceral metastasis and 74 (55.2%) had more than three sites of metastases. The ORR of SOX regimen was 38.5% (95% confidence interval [CI], 26.9 to 50.0) with a median TTP of 6.0 months (95% CI, 5.1 to 6.9). Median DoR and OS were 10.3 months (95% CI, 5.5 to 15.1) and 19.4 (95% CI, not estimated) months, respectively. Grade 3 or 4 neutropenia was reported in 28 patients (32.1%) and thrombocytopenia was observed in 23 patients (26.6%).
Conclusion
This phase II study showed that SOX regimen is a reasonable option in metastatic breast cancer previously treated with anthracyclines and taxanes.
10.The Expression of Programmed Death-Ligand 1 on Immune Cells Is Related to a Better Prognosis in Biliary Tract Cancer
Sung Chan KWON ; Seungmin BANG ; Young Nyun PARK ; Ji Hoon PARK ; So Jeong KIM ; Jung Hyun JO ; Moon Jae CHUNG ; Jeong Youp PARK ; Seung Woo PARK ; Si Young SONG ; Eunhyang PARK ; Hee Seung LEE
Gut and Liver 2023;17(6):933-941
Background/Aims:
Programmed death-ligand 1 (PD-L1) expression in tumor cells is associated with a poor biliary tract cancer (BTC) prognosis; tumor-infiltrating immune cells in the tumor microenvironment are associated with a better prognosis. The effect of PD-L1 expression on immune cells on survival is unclear. We investigated the relationship between PD-L1 expression in immune cells and BTC prognosis.
Methods:
PD-L1 expression was evaluated using an anti-PD-L1 22C3 mouse monoclonal primary antibody, and its relationships with clinical characteristics and prognosis were analyzed using the Cox proportional hazard model to investigate the prognostic performance of PD-L1 in BTC.
Results:
Among 144 analyzed cases, patients with positive PD-L1 expression in tumor cells and negative PD-L1 expression in immune cells showed poorer overall survival rates than those exhibiting other expressions (tumor cells: hazard ratio [HR]=1.023, p<0.001; immune cells: HR=0.983, p=0.021). PD-L1 expression in tumor cells was an independent predictor of poor overall survival (HR=1.024, p<0.001). In contrast, PD-L1 expression in immune cells was a predictive marker of good prognosis (HR=0.983, p=0.018).
Conclusions
PD-L1 expression in immune cells may be used as an independent factor to evaluate the prognosis of patients with BTC.

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