1.Secondary Metabolites of Hemerocallis fulva var. kwanso Regel and Their PTP1B Inhibitory Potential
Thi Thanh LE ; Manh Tuan HA ; Trong Trieu TRAN ; Seung Eui MIN ; Kang-Hyun HAN ; Jungmoo HUH ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2026;32(1):76-83
A phytochemical study of the root extract of Hemerocallis fulva var. kwanso Regel resulted in the isolation and structural characterization of four lignans (1‒4), three flavanones (5, 6, and 8), one chalcone (9), and two monoterpenes (7 and 10). Enzyme inhibition assays revealed that two flavanone glucosides (5 and 6) showed significant inhibitory effect against protein tyrosine phosphatase 1B (PTP1B), with IC50 values of 31.38 µM and 51.46 µM, respectively. Further enzyme kinetic studies demonstrated that these two compounds acted as noncompetitive PTP1B inhibitors, with Ki values of 30.88 µM and 50.38 µM, respectively.
2.PTP1B Inhibitory Constituents from Dystaenia takeshimana: Mechanistic Insights via Kinetic and Molecular Docking Analyses
Manh Tuan HA ; Trong Trieu TRAN ; Thu Huong TRAN ; Jungmoo HUH ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2026;32(1):56-62
Dystaenia takeshimana (Nakai) Kitagawa belongs to the family Apiaceae (Umbelliferae) and is a perennial herb naturally endemic to Ulleung Island, Republic of Korea. Following its successful introduction and cultivation in mainland Korea, a phytochemical investigation of this plant was carried out. As a result, thirteen compounds were isolated and structurally characterized, including one flavonoid glycoside (1), two polyacetylenes (2 and3), one caffeoylquinic acid derivative (4), one aliphatic hydroxy acid (5), four phenolic acids and their derivatives(6, 8–10), one aromatic alcohol derivative (7), two carbohydrates (11 and 12), and one phytosterol (13). The structures of these compounds were elucidated based on spectroscopic analyses and comparison with previously reported literature data. To the best of our knowledge, this study represents the first report on the isolation of falcarinol (2), trans-4-hydroxy-2-nonenoic acid (5), and sucrose (11) from D. takeshimana and the evaluation of their protein tyrosine phosphatase 1B (PTP1B) inhibitory activity. Compounds 2, 3, and 5 exhibited potent PTP1B inhibitory effects with IC50 values of 10.74, 8.31, and 25.24 µM, respectively. Enzyme kinetic studies indicated noncompetitive inhibition by 2 and mixed-type inhibition by 5 against PTP1B. Furthermore, molecular docking analysis was performed to investigate the binding interactions between the active compounds and the enzyme active site.
3.A New Methoxyflavonoid Rutinoside and PTP1B-Inhibitory Phenolic Compounds from the Water Extract of Areca catechu L.
Manh Tuan HA ; Trong Trieu TRAN ; Thu Huong TRAN ; Seung Eui MIN ; Sang-Jin PARK ; Kang-Hyun HAN ; Jungmoo HUH ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2026;32(1):50-55
Phytochemical investigation of the water extract and alkaloid fraction of Areca catechu L. led to theisolation of one new methoxyflavonoid rutinoside (1), together with eleven known compounds (2−12), five of which (8−12) belong to the pyridine alkaloid class. The structure of the new compound was elucidated through extensive spectroscopic analyses, including 1D and 2D NMR experiments and high-resolution mass spectrometry.Notably, rhamnazin-3-O-rutinoside (2) is reported here for the first time from this species. The isolated compounds were evaluated for their inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) using a p-nitrophenyl phosphate assay. Flavonoids (3 and 4) and stilbene (5) exhibited notable inhibitory activity, with IC50 values of 13.30 ± 0.71, 13.44 ± 0.84, and 8.68 ± 0.12 μM, respectively. In contrast, methoxyflavonoid rutinosides (1 and 2) and pyridine alkaloids (8−12) did not show significant inhibitory activity against PTP1B.These findings provide additional chemical insights into A. catechu and its constituents in relation to PTP1B inhibition.
4.A 19F Blake Drain versus a 28F Conventional Drain Following Video-Assisted Thoracoscopic Esophagectomy for Esophageal Cancer: A Comparative Retrospective Study
Hiep Van PHAM ; Tuan Anh NGUYEN ; Thang Manh TRAN
Journal of Chest Surgery 2026;59(1):30-36
Background:
Pleural drainage is essential for preventing and managing respiratory complications after video-assisted thoracoscopic esophagectomy (VATE). Conventional largebore drains often cause significant pain. Small-bore drains (e.g., 19F Blake drains) may reduce discomfort; however, evidence regarding their use in VATE is limited. This study compared drainage effectiveness and pain between 19F Blake drains and conventional 28F drains after VATE for esophageal cancer.
Methods:
This retrospective study included 77 male patients with middle- or lower-third esophageal cancer who underwent VATE with laparoscopic retrosternal tunneling from November 2018 to November 2022. Fifty-five patients received a 28F conventional drain, and 22 received a 19F Blake drain. Outcomes included drainage duration and volume, pain levels (Visual Analog Scale [VAS]), postoperative pneumonia rates, and pulmonary function (forced vital capacity [FVC], forced expiratory volume in 1 second [FEV1]) on postoperative day 3.
Results:
The 19F group reported significantly lower pain scores on postoperative days 1–3 (VAS: 2.95–3.25 vs. 4.07–4.62, p<0.001). Drainage duration and pneumonia rates were similar between groups. The 19F group demonstrated a trend toward higher drainage volume and significantly better preservation of pulmonary function, with smaller declines in FVC (ΔFVC: 0.24±0.20 L vs. 0.63±0.17 L, p<0.001) and FEV1 (ΔFEV1: 0.38±0.25 L vs. 0.58±0.25 L, p=0.02).
Conclusion
19F Blake drains provide similar drainage effectiveness to that of 28F drains, with reduced postoperative pain and better pulmonary function preservation. These findings support the use of 19F Blake drains to improve patient comfort and recovery following VATE.
5.Bullous Erysipelas: A Case Highlighting Diagnostic and Therapeutic Management
Thien NGUYE ; Phuoc Nghia TRAN ; Anh Phuong DANG ; Tuan Anh VU
Brunei International Medical Journal 2026;22():35-38
Case Report Open Access 15 Methaemoglobinaemia is a rare but potentially life -threatening cause of hypoxemia that may be overlooked in emergency settings. We report a case of acquired methaemoglobinaemia in a 36 - year-old man following inhalation of an alkyl nitrite –containing recreational product (“Super Rush ”). The patient presented with cyanosis and hypoxemia on pulse oximetry despite minimal symptoms and preserved arterial oxygen tension. Diagnosis was confirmed by co -oximetry demonstrating elevated methaemoglobin levels. Prompt treatment with intravenous methylene blue led to rapid clinical and biochemical improvement. This case highlights the importance of suspecting and recognising recreational inhalants as a cause of methaemoglobinaemia and the utility of co -oximetry in patients with unexplained cyanosis and a saturation gap
6.Bullous Erysipelas: A Case Highlighting Diagnostic and Therapeutic Management
Thien NGUYE ; Phuoc Nghia TRAN ; Anh Phuong DANG ; Tuan Anh VU
Brunei International Medical Journal 2026;22():35-38
Case Report Open Access 15 Methaemoglobinaemia is a rare but potentially life -threatening cause of hypoxemia that may be overlooked in emergency settings. We report a case of acquired methaemoglobinaemia in a 36 - year-old man following inhalation of an alkyl nitrite –containing recreational product (“Super Rush ”). The patient presented with cyanosis and hypoxemia on pulse oximetry despite minimal symptoms and preserved arterial oxygen tension. Diagnosis was confirmed by co -oximetry demonstrating elevated methaemoglobin levels. Prompt treatment with intravenous methylene blue led to rapid clinical and biochemical improvement. This case highlights the importance of suspecting and recognising recreational inhalants as a cause of methaemoglobinaemia and the utility of co -oximetry in patients with unexplained cyanosis and a saturation gap
7.A predictive nomogram for selective screening of asymptomatic vertebral fractures: The Vietnam Osteoporosis Study
T. NGUYEN ; Bao T. NGUYEN ; An V. TRAN ; Tan T. NGUYEN ; Long H. NGO ; Tam VO ; Thi H NHUNG THAI ; Linh D. MAI ; Thach S. TRAN ; Tuan V. NGUYEN ; Lan T. HO-PHAM
Osteoporosis and Sarcopenia 2025;11(1):9-14
Objectives:
Vertebral fractures are associated with disability and mortality, but most vertebral fractures are asymptomatic. The present study aimed to determine the incidence of and develop a predictive nomogram for asymptomatic vertebral fractures in Vietnamese adults.
Methods:
This cohort study as a part of the Vietnam Osteoporosis Study involved 168 men and 287 women aged 50 years and older without a clinically diagnosed vertebral fracture. Their spine x-rays were taken at the recruitment and subsequent 2-year visit. Vertebral fractures were ascertained using the Genant’s semiquantitative method. We employed the Bayesian Model Averaging method to search for the optimal model for predicting asymptomatic vertebral fractures. A predictive nomogram was also developed to facilitate risk prediction.
Results:
During a median of 2.38 years of follow-up, 13 men and 16 women developed an asymptomatic vertebral fracture, yielding the overall incidence rate of 28 fractures per 1000 person-years, or 33 fractures/1000 personyears in men and 24 fractures/1000 person-years in women, respectively. Most asymptomatic vertebral fractures were moderate, almost 1.5 times more common than mild fractures. The optimal model for predicting incident asymptomatic vertebral fractures included age, male sex and lower femoral neck T-score. The area under the receiver’s operating characteristic curve was 0.91, with 95% CI ranging from 0.86 to 0.96.
Conclusions
Asymptomatic vertebral fractures were relatively common among adults in Vietnam. A simple model with sex, age and femoral neck T-score is helpful for selective screening of asymptomatic vertebral fractures in Vietnamese individuals.
8.Anti-inflammatory Constituents from Artemisia iwayomogi Kitamura: A Bioassay-guided Fractionation Study
Ngoc Khanh VU ; Thi Thanh LE ; Trong Trieu TRAN ; Manh Tuan HA ; Jeong Ah KIM ; Byung Sun MIN
Natural Product Sciences 2025;31(1):43-48
Bioassay-guided fractionation of the methanolic extract of Artemisia iwayomogi Kitamura led to the isolation of 12 known compounds (1‒12). Notably, this study marks the first report of 3-epimeridinol (1) being isolated and structurally characterized from a natural source. Additionally, compounds 3, 4, and 7 were isolated from the Asteraceae family for the first time. The structural elucidation of the isolated compound was achieved through analysis of 1D, 2D NMR, and MS data. Upon evaluation of their inhibitory effects against lipopolysaccharideinduced nitric oxide production, compound 12 demonstrated significant inhibitory activity with greater potency than the reference compound quercetin. These results established A. iwayomogi as a promising source of antiinflammatory agents.
9.A predictive nomogram for selective screening of asymptomatic vertebral fractures: The Vietnam Osteoporosis Study
T. NGUYEN ; Bao T. NGUYEN ; An V. TRAN ; Tan T. NGUYEN ; Long H. NGO ; Tam VO ; Thi H NHUNG THAI ; Linh D. MAI ; Thach S. TRAN ; Tuan V. NGUYEN ; Lan T. HO-PHAM
Osteoporosis and Sarcopenia 2025;11(1):9-14
Objectives:
Vertebral fractures are associated with disability and mortality, but most vertebral fractures are asymptomatic. The present study aimed to determine the incidence of and develop a predictive nomogram for asymptomatic vertebral fractures in Vietnamese adults.
Methods:
This cohort study as a part of the Vietnam Osteoporosis Study involved 168 men and 287 women aged 50 years and older without a clinically diagnosed vertebral fracture. Their spine x-rays were taken at the recruitment and subsequent 2-year visit. Vertebral fractures were ascertained using the Genant’s semiquantitative method. We employed the Bayesian Model Averaging method to search for the optimal model for predicting asymptomatic vertebral fractures. A predictive nomogram was also developed to facilitate risk prediction.
Results:
During a median of 2.38 years of follow-up, 13 men and 16 women developed an asymptomatic vertebral fracture, yielding the overall incidence rate of 28 fractures per 1000 person-years, or 33 fractures/1000 personyears in men and 24 fractures/1000 person-years in women, respectively. Most asymptomatic vertebral fractures were moderate, almost 1.5 times more common than mild fractures. The optimal model for predicting incident asymptomatic vertebral fractures included age, male sex and lower femoral neck T-score. The area under the receiver’s operating characteristic curve was 0.91, with 95% CI ranging from 0.86 to 0.96.
Conclusions
Asymptomatic vertebral fractures were relatively common among adults in Vietnam. A simple model with sex, age and femoral neck T-score is helpful for selective screening of asymptomatic vertebral fractures in Vietnamese individuals.
10.Effectiveness of biportal endoscopic lumbar interbody fusion using the multi-layer bone grafting technique: a retrospective study from Vietnam
Tran Vu Hoang DUONG ; Pham Anh TUAN ; Huynh Van VU ; Chu Van LAM ; Le Tan LINH ; Phan DUY ; Wongthawat LIAWRUNGRUEANG
Asian Spine Journal 2025;19(2):228-241
Methods:
This study included 41 patients with single-level grades 1 or 2 LS from February 2023 to February 2024. Clinical outcomes were assessed using the Visual Analog Scale (VAS) for back and leg pain and the Oswestry Disability Index (ODI). Bridwell fusion grades were evaluated via lumbar spine computed tomography performed 6 months postoperatively.
Results:
Over a mean follow-up period of 10.6 months (range, 7–18 months), significant improvements were observed in VAS scores for low back pain (from 7.8±0.8 to 2.1±1.4) and leg pain (from 8.1±1.3 to 1.9±1.5) as well as ODI scores (from 50.4±15.4 to 14.8±10.5). The cohort consisted of patients with grades 1 (73.2%) and 2 LS (26.8%) at L4–L5 (58.6%), L5–S1 (34.1%), and L3–L4 (7.3%) levels. The mean operation time was 182.8±36.4 minutes, with a mean intraoperative blood loss of 190.5±81.3 mL and a mean hospital stay of 7.2±3.6 days. Successful fusion (Bridwell grades I/II) was achieved in 82.9% of the cases, with a 4.9% incidence of cage subsidence. Minor complications included durotomies in two patients (4.9%), whereas no major complications, such as nerve root injury, hardware-related issues, or postoperative infections, were reported.
Conclusions
The described BE-LIF technique, using HA bone grafts, which are an autologous bone from the preserved IAP, and a TLIF cage, is a viable, safe, and effective option for treating low-grade LS. This approach achieves favorable clinical outcomes and high fusion rates, which provides a cost-effective alternative to advanced surgical implants.


Result Analysis
Print
Save
E-mail