1.Lessons from the 2024–2025 measles outbreak in southern Viet Nam
Thang Nguyen-Tien ; Hoa Minh Tran ; Anh Vu Le
Western Pacific Surveillance and Response 2026;17(2):64-67
Dong Nai province in southern Viet Nam was among the hardest hit in a measles outbreak in 2024–2025 with over 7000 cases. Our analysis outlines major takeaways for measles control in recommending the need for strengthened surveillance, digital communication and intersectoral collaboration to address immunization gaps and build health system resilience in Viet Nam.
2.Production, purification and characterization of novel protease from Bacillus amyloliquefaciens D19 isolated in Vietnam
Tan Viet Pham ; Hanh Thi Dieu Nguyen ; Thi Luyen Bui ; Ngoc An Nguyen
Malaysian Journal of Microbiology 2024;20(no.1):85-93
Aims:
Microorganisms play a vital role in the breakdown of natural organic compounds and are valuable objects for worldwide enzyme production. The aim of this study was to identify favorable production conditions for Bacillus amyloliquefaciens D19 protease, followed by the purification and chemical characterization of this novel enzyme to assess its potential applications in various fields.
Methodology and results:
In this study, favorable conditions of protease production from B. amyloliquefaciens D19 were determined using a medium containing soluble starch (1.5%), earthworm extract (1.0%), yeast extract (0.5%), NaCl
(1.0%), at pH 7.0-8.0, 37 °C for 36 h with 150 rpm shaking condition. The protease was purified and had a molecular weight of about 23 kDa. The optimum condition for casein hydrolysis was at 40 °C and pH 6.5-7.0 in the presence of 1.0 mM Na+ or 5.0 mM Zn2+. The enzymatic activity was maintained at 75-100% at 30-50 °C and in pH 6.0-10.0. The values of Vmax and KM were also determined as 1547 U/mg and 6.33 mg/mL, respectively.
Conclusion, significance and impact of study
The identified optimal conditions will serve as the foundation for the production of the 23 kDa B. amyloliquefaciens D19 protease, one of the smallest proteases within the Bacillus genus. Moreover, its notable heat resistance, broad pH tolerance, high substrate catalysis and moderate substrate binding affinity make this enzyme a promising candidate for various applications in the food-feed and brewing industries.
3.8-Methoxypsoralen Induces Apoptosis by Upregulating p53 and Inhibits Metastasis by Downregulating MMP-2 and MMP-9 in Human Gastric Cancer Cells
Eun Kyoung CHOI ; Hae Dong KIM ; Eun Jung PARK ; Seuk Young SONG ; Tien Thuy PHAN ; Miyoung NAM ; Minjung KIM ; Dong-Uk KIM ; Kwang-Lae HOE
Biomolecules & Therapeutics 2023;31(2):219-226
Furanocoumarin 8-methoxypsoralen (8-MOP) is the parent compound that naturally occurs in traditional medicinal plants used historically. 8-MOP has been employed as a photochemotherapeutic component of Psoralen + Ultraviolet A (PUVA) therapy for the treatment of vitiligo and psoriasis. Although the role of 8-MOP in PUVA therapy has been studied, little is known about the effects of 8-MOP alone on human gastric cancer cells. In this study, we observed anti-proliferative effect of 8-MOP in several human cancer cell lines. Among these, the human gastric cancer cell line SNU1 is the most sensitive to 8-MOP. 8-MOP treated SNU1 cells showed G1-arrest by upregulating p53 and apoptosis by activating caspase-3 in a dose-dependent manner, which was confirmed by loss-of-function analysis through the knockdown of p53-siRNA and inhibition of apoptosis by Z-VAD-FMK. Moreover, 8-MOPinduced apoptosis is not associated with autophagy or necrosis. The signaling pathway responsible for the effect of 8-MOP on SNU1 cells was confirmed to be related to phosphorylated PI3K, ERK2, and STAT3. In contrast, 8-MOP treatment decreased the expression of the typical metastasis-related proteins MMP-2, MMP-9, and Snail in a p53-independent manner. In accordance with the serendipitous findings, treatment with 8-MOP decreased the wound healing, migration, and invasion ability of cells in a dose-dependent manner. In addition, combination treatment with 8-MOP and gemcitabine was effective at the lowest concentrations. Overall, our findings indicate that oral 8-MOP has the potential to treat early human gastric cancer, with fewer side effects.
4.Diabetes and Risk of Hepatocellular Carcinoma in Cirrhosis Patients with Nonalcoholic Fatty Liver Disease
Pai-Chi TENG ; Daniel Q. HUANG ; Ting-Yi LIN ; Mazen NOUREDDIN ; Ju Dong YANG
Gut and Liver 2023;17(1):24-33
Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the world. NAFLD is a hepatic manifestation of insulin resistance, the core pathophysiology of diabetes. Multiple clinical studies show that diabetes increases the risk of liver disease progression and cirrhosis development in patients with NAFLD. Diabetes has causal associations with many different cancers, including hepatocellular carcinoma (HCC). More recent studies demonstrate that diabetes increases the risk of HCC in patients with underlying NAFLD cirrhosis, confirming the direct hepatocarcinogenic effect of diabetes among cirrhosis patients. Diabetes promotes hepatocarcinogenesis via the activation of inflammatory cascades producing reactive oxygen species and proinflammatory cytokines, leading to genomic instability, cellular proliferation, and inhibition of apoptosis. Given the global increase in the burden of NAFLD and HCC, high-risk patients such as older diabetic individuals should be carefully monitored for HCC development. Future larger studies should explore whether the effect of diabetes on HCC risk in NAFLD cirrhosis is modifiable by the type of antidiabetic medication and the effectiveness of diabetes control.
5.Machine learning models compared to existing criteria for noninvasive prediction of endoscopic retrograde cholangiopancreatography-confirmed choledocholithiasis
Camellia Dalai ; John M Azizian ; Harry Trieu ; Anand Rajan ; Formosa C Chen ; Tien Dong ; Simon W Beaven ; James H. Tabibian
Liver Research 2021;5(4):224-231
Background and aims
Noninvasive predictors of choledocholithiasis have generally exhibited marginal performance characteristics. We aimed to identify noninvasive independent predictors of endoscopic retrograde cholangiopancreatography (ERCP)-confirmed choledocholithiasis and accordingly developed predictive machine learning models (MLMs).
Methods
Clinical data of consecutive patients undergoing first-ever ERCP for suspected choledocholithiasis from 2015 to 2019 were abstracted from a prospectively-maintained database. Multiple logistic regression was used to identify predictors of ERCP-confirmed choledocholithiasis. MLMs were then trained to predict ERCP-confirmed choledocholithiasis using pre-ERCP ultrasound (US) imaging only as well as using all available noninvasive imaging (US, computed tomography, and/or magnetic resonance cholangiopancreatography). The diagnostic performance of American Society for Gastrointestinal Endoscopy (ASGE) “high-likelihood” criteria was compared to MLMs.
Results
We identified 270 patients (mean age 46 years, 62.2% female, 73.7% Hispanic/Latino, 59% with noninvasive imaging positive for choledocholithiasis) with native papilla who underwent ERCP for suspected choledocholithiasis, of whom 230 (85.2%) were found to have ERCP-confirmed choledocholithiasis. Logistic regression identified choledocholithiasis on noninvasive imaging (odds ratio (OR) = 3.045, P = 0.004) and common bile duct (CBD) diameter on noninvasive imaging (OR = 1.157, P = 0.011) as predictors of ERCP-confirmed choledocholithiasis. Among the various MLMs trained, the random forest-based MLM performed best; sensitivity was 61.4% and 77.3% and specificity was 100% and 75.0%, using US-only and using all available imaging, respectively. ASGE high-likelihood criteria demonstrated sensitivity of 90.9% and specificity of 25.0%; using cut-points achieving this specificity, MLMs achieved sensitivity up to 97.7%.
Conclusions
MLMs using age, sex, race/ethnicity, presence of diabetes, fever, body mass index (BMI), total bilirubin, maximum CBD diameter, and choledocholithiasis on pre-ERCP noninvasive imaging predict ERCP-confirmed choledocholithiasis with good sensitivity and specificity and outperform the ASGE criteria for patients with suspected choledocholithiasis.
6.Econazole Induces p53-Dependent Apoptosis and Decreases Metastasis Ability in Gastric Cancer Cells
Eun Kyoung CHOI ; Eun Jung PARK ; Tien Thuy PHAN ; Hea Dong KIM ; Kwang-Lae HOE ; Dong-Uk KIM
Biomolecules & Therapeutics 2020;28(4):370-379
Econazole, a potent broad-spectrum antifungal agent and a Ca2+ channel antagonist, induces cytotoxicity in leukemia cells and is used for the treatment of skin infections. However, little is known about its cytotoxic effects on solid tumor cells. Here, we investigated the molecular mechanism underlying econazole-induced toxicity in vitro and evaluated its regulatory effect on the metastasis of gastric cancer cells. Using the gastric cancer cell lines AGS and SNU1 expressing wild-type p53 we demonstrated that econazole could significantly reduce cell viability and colony-forming (tumorigenesis) ability. Econazole induced G0/G1 phase arrest, promoted apoptosis, and effectively blocked proliferation- and survival-related signal transduction pathways in gastric cancer cells. In addition, econazole inhibited the secretion of matrix metalloproteinase- 2 (MMP-2) and MMP-9, which degrade the extracellular matrix and basement membrane. Econazole also effectively inhibited the metastasis of gastric cancer cells, as confirmed from cell invasion and wound healing assays. The protein level of p53 was significantly elevated after econazole treatment of AGS and SNU1 cells. However, apoptosis was blocked in econazole-treated cells exposed to a p53-specific small-interfering RNA to eliminate p53 expression. These results provide evidence that econazole could be repurposed to induce gastric cancer cell death and inhibit cancer invasion.
7.Kalopanaxsaponin A Exerts Anti-Inflammatory Effects in Lipopolysaccharide-Stimulated Microglia via Inhibition of JNK and NF-kappaB/AP-1 Pathways.
Yeon Hui JEONG ; Jin Won HYUN ; Tien KIM VAN LE ; Dong Hyun KIM ; Hee Sun KIM
Biomolecules & Therapeutics 2013;21(5):332-337
Microglial activation plays an important role in the development and progression of various neurological disorders such as cerebral ischemia, multiple sclerosis, and Alzheimer's disease. Thus, controlling microglial activation can serve as a promising therapeutic strategy for such brain diseases. In the present study, we showed that kalopanaxsaponin A, a triterpenoid saponin isolated from Kalopanax pictus, inhibited inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and tumor necrosis factor (TNF)-alpha expression in lipopolysaccharide (LPS)-stimulated microglia, while kalopanaxsaponin A increased anti-inflammatory cytokine interleukin (IL)-10 expression. Subsequent mechanistic studies revealed that kalopanaxsaponin A inhibited LPS-induced DNA binding activities of NF-kappaB and AP-1, and the phosphorylation of JNK without affecting other MAP kinases. Furthermore, kalopanaxsaponin A inhibited the intracellular ROS production with upregulation of anti-inflammatory hemeoxygenase-1 (HO-1) expression. Based on the previous reports that JNK pathway is largely involved in iNOS and proinflammatory cytokine gene expression via modulating NF-kappaB/AP-1 and ROS, our data collectively suggest that inhibition of JNK pathway plays a key role in anti-inflammatory effects of kalopanaxsaponin A in LPS-stimulated microglia.
Alzheimer Disease
;
Brain Diseases
;
Brain Ischemia
;
Cyclooxygenase 2
;
DNA
;
Gene Expression
;
Interleukins
;
Kalopanax
;
MAP Kinase Signaling System
;
Microglia*
;
Multiple Sclerosis
;
Nervous System Diseases
;
NF-kappa B
;
Nitric Oxide Synthase Type II
;
Phosphorylation
;
Phosphotransferases
;
Saponins
;
Transcription Factor AP-1
;
Tumor Necrosis Factor-alpha
;
Up-Regulation


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