Amentoflavone Acts as a Radioprotector for Irradiated v79 Cells by Regulating Reactive Oxygen Species (ROS), Cell Cycle and Mitochondrial Mass

Xu, Ping,Jiang, En-Jin,Wen, Si-Yuan,Lu, Dan-Dan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

Radioprotective effects of amentoflavone were investigated by examining cell viability, apoptosis, cell cycling concentrations of intracellular ROS (reactive oxygen species), and relative mitochondrial mass by flow cytometry after $^{60}Co$ irradiation. Pretreatment with amentoflavone 24 hours prior to 8 Gy $^{60}Co$ ${\gamma}$-ray irradiation significantly inhibited apoptosis, promoted the G2 phase, decreased the concentration of ROS and mitochondrial mass. These results collectively indicate that amentoflavone is an effective radioprotective agent.

Glycosyltransformation of ginsenoside Rh2 into two novel ginsenosides using recombinant glycosyltransferase from Lactobacillus rhamnosus and its in vitro applications

Dan-Dan Wang,Yeon-Ju Kim,Nam In Baek,Ramya Mathiyalagan,Chao Wang,Yan Jin,Xing Yue Xu,Deok-Chun Yang 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.1

Background: Ginsenoside Rh2 is well known for many pharmacological activities, such as anticancer, antidiabetes, antiinflammatory, and antiobesity properties. Glycosyltransferases (GTs) are ubiquitous enzymes present in nature and are widely used for the synthesis of oligosaccharides, polysaccharides, glycoconjugates, and novel derivatives. We aimed to synthesize new ginsenosides from Rh2 using the recombinant GT enzyme and investigate its cytotoxicity with diverse cell lines. Methods: We have used a GT gene with 1,224-bp gene sequence cloned from Lactobacillus rhamnosus (LRGT) and then expressed in Escherichia coli BL21 (DE3). The recombinant GT protein was purified and demonstrated to transform Rh2 into two novel ginsenosides, and they were characterized by nuclear magnetic resonance (NMR) techniques and evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay. Results: Two novel ginsenosides with an additional glucopyranosyl (6/1) and two additional glucopyranosyl (6/1) linked with the C-3 position of the substrate Rh2 were synthesized, respectively. Cell viability assay in the lung cancer (A549) cell line showed that glucosyl ginsenoside Rh2 inhibited cell viability more potently than ginsenoside Rg3 and Rh2 at a concentration of 10 μM. Furthermore, glucosyl ginsenoside Rh2 did not exhibit any cytotoxic effect in murine macrophage cells (RAW264.7), mouse embryo fibroblasts cells (3T3-L1), and skin cells (B16BL6) at a concentration of 10 μM compared with ginsenoside Rh2 and Rg3. Conclusion: This is the first report on the synthesis of two novel ginsenosides, namely, glucosyl ginsenoside Rh2 and diglucosyl ginsenoside Rh2 from Rh2 by using recombinant GT isolated from L. rhamnosus. Moreover, diglucosyl ginsenoside Rh2 might be a new candidate for treatment of inflammation, obesity, and skin whiting, and especially for anticancer.

Association Between the Ku70-1310C/G Promoter Polymorphism and Cancer Risk: a Meta-analysis

Xu, Lu,Ju, Xiao-Bing,Li, Pu,Wang, Jue,Shi, Zhu-Mei,Zheng, Ming-Jie,Xue, Dan-Dan,Xu, Yan-Jie,Yin, Yong-Mei,Wang, Shui,You, Yong-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2

Ku70 plays an important role in DNA double-strand break repair. Studies revealing conflicting results on the role of the Ku70-1310C/G promoter polymorphism on cancer risk led us to perform a meta-analysis to investigate this relationship. Ten case-control studies with 2566 cases and 3058 controls were identified. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of associations. The overall results suggested no association between the Ku70-1310C/G promoter polymorphism and total cancer risk. However, on stratified analysis, significantly increased risks were observed among the Asian population (GG vs. CC: OR=1.50, 95%CI=1.10-2.06; GG vs. CC/CG: OR=1.47, 95%CI=1.07-2.01) and population-based case-control studies (GG vs. CC: OR=1.57, 95%CI=1.12-2.22; CG vs. CC: OR=1.35, 95%CI=1.11-1.64; CG/GG vs. CC: OR=1.37, 95%CI=1.14-1.65). Additionally, variant genotypes were associated with a significantly increased breast cancer risk (GG vs. CC: OR=1.80, 95%CI=1.26-2.56; GG vs. CC/CG: OR=1.40, 95%CI=1.01-1.95).

Homicidal Poisoning of Heroin and Estazolam : Autopsy and Pathological Findings, Toxicological Analysis

Dan Liu,Shangxun Li,Xiangtao Ma,Jinxue Gao,Liang Xu,Jun He,Yuhong Li,Dan Yan,Yiwu Zhou,Qingming Wu 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.4

We reported an unusual homicidal case in which a 40-year-old woman was deceived into drinking a cup of milk that had 72 tablets of estazolam (2mg/tablet) dissolved in, and then being injected heroin aqueous solution on the right deltoid region by the criminal. At autopsy, pinpoint pupils and a new injection site on the right deltoid region were found. The pathologic pictures showed multiple patchy hemorrhages and considerable amounts of foreign amorphous substance with yellow appearance at the injection site. Some double refracting crystals with the forms of Maltese cross, acicular, rhomb or irregular were found by polarizing microscope, which may result from the diluent in heroin such as starch. Toxicological qualitative analysis by gas chromatography mass spectrometry (GC-MS) demonstrated the presence of benzodiazepine and morphine in blood and urine, and heroin in the injector left at scene. Quantitative analysis was also performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), providing the data on distribution of 6-monoacetylmorphine, morphine and estazolam in the woman’s body. And the cause of death was determined to polydrug heroin-related deaths due to the combined poisoning of heroin and estazolam. It taught a lesson that the determination of other drugs, particularly central nervous system depressants in heroin poisoning were quite important in forensic expertise.

Analysis of the Magnetization Effect of Permanent Magnets on the Nonlinear Magnetic Characteristic Distributions of a Balanced Armature Receiver

Xu, Dan-Ping,Jiang, Yuan-Wu,Hwang, Sang-Moon IEEE 2019 IEEE transactions on magnetics Vol.55 No.2

<P>Balanced armature (BA) receivers are widely used due to their small size and good performance. The magnetization of the permanent magnets (PMs) affects the nonlinear magnetic characteristics, which can affect the performance of a BA receiver. In this paper, four different magnetizations were simulated to examine the influence of magnetization on the cogging force, force factor, inductance, and speedance. The simulation results show that the nonlinearity is more obvious with larger magnetization of the PMs and approach a limit when there is saturation in the magnetic circuit. In addition, within a small vibration position or current range, the influence of the magnetization on the cogging force, force factor, and speedance can be treated as linear, and there is no influence on inductance. Based on the simulated nonlinear magnetic characteristics, the vibration displacement can be solved with coupling analyses. The cogging force also affects the displacement resonance frequency. The force factor has a big effect on the vibration displacement at low frequency. Two samples with different magnetizations were made, and the simulation results were verified experimentally.</P>

Assessment of Esophageal Motor Disorders Using High-resolution Manometry in Esophageal Dysphagia With Normal Endoscopy

Dan Wang,Xiu Wang,Yao Yu,Xiaowen Xu,Jing Wang,Yuting Jia,Hong Xu 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.1

Background/Aims The distribution and esophageal motor characteristics of Chinese patients with esophageal dysphagia who exhibit no structural abnormalities on esophagogastroduodenoscopy remain unclear. Our aim is to assess the esophageal motor patterns using high-resolution manometry (HRM) and classify them according to the Chicago classification version 3.0 (CC v3.0). Furthermore, we compared the CC v3.0 and the previous version 2.0 (CC v2.0) for diagnosis of motor disorders. Methods Two hundred thirty-six (mean age 48.4 ± 12.2 years, 61.9% female) patients with esophageal dysphagia were included for analysis of motor function using HRM. All participants were administered a questionnaire to determine Eckardt scores before HRM. Results According to the CC v3.0, 57 (24.2%) patients showed evidence of esophagogastric junction outflow obstruction and were classified as Group 1. Eighteen (7.6%) patients with major disorders of peristalsis were classified as Group 2. Minor disorders of peristalsis (Group 3) were much more frequent (129 [54.7%] patients). Thirty-two (13.6%) patients had normal esophageal manometry were classified as Group 4. All patients with abnormal pH or pH impedance monitoring (n = 44) had minor motor disorders (ineffective esophageal motility [IEM] = 34, fragmented peristalsis = 10). Based on motor category, the Eckardt score was 4.7 ± 0.1 in Group 1, 4.5 ± 0.3 in Group 2, 3.5 ± 0.1 in Group 3, and 3.9 ± 0.1 in Group 4. Conclusions IEM was the most common esophageal motor disorder in patients with esophageal dysphagia who showed no structural abnormality on endoscopy. While a high Eckardt score suggests outflow obstruction or a major motor disorder, a low score suggests IEM.

EBV-miR-BHRF1-1 Targets p53 Gene: Potential Role in Epstein-Barr Virus Associated Chronic Lymphocytic Leukemia

Dan-Min Xu,Yi-Lin Kong,Li Wang,Hua-Yuan Zhu,Jia-Zhu Wu,Yi Xia,Yue Li,Shu-Chao Qin,Lei Fan,Jian-Yong Li,Jin-Hua Liang,Wei Xu 대한암학회 2020 Cancer Research and Treatment Vol.52 No.2

Purpose The purpose of this study was to investigate the prognostic impact of Epstein-Barr virus (EBV)–microRNA (miRNA, miR)-BHRF1-1 with chronic lymphocytic leukemia (CLL) as well as role of EBV-miR-BHRF1-1 in p53 gene. Materials and Methods Quantitative reverse transcription–polymerase chain reaction and western blotting were used to quantify EBV-miR-BHRF1-1 and p53 expression in cultured CLL. Results p53 aberration was associated with the higher expression level of EBV-miR-BHRF1-1 (p < 0.001) which was also an independent prognostic marker for overall survival (p=0.028; hazard ratio, 5.335; 95% confidence interval, 1.193 to 23.846) in 97 newly-diagnosed CLL patients after adjusted with International Prognostic Index for patients with CLL. We identified EBV-miR-BHRF1-1 as a viral miRNA regulator of p53. EBV-miR-BHRF1-1 repressed luciferase reporter activity by specific interaction with the seed region within the p53 3- untranslated region. Discordance of p53 messenger RNA and protein expression was associated with high EBV-miR-BHRF1-1 levels in CLL patients and cell lines. EBV-miR-BHRF1- 1 inhibition upregulated p53 protein expression, induced cell cycle arrest and apoptosis and decreased cell proliferation in cell lines. EBV-miR-BHRF1-1 mimics downregulated p53 protein expression, decreased cell cycle arrest and apoptosis, and induced cell proliferation in cell lines. Conclusion This study supported the role of EBV-miR-BHRF1-1 in p53 regulation in vitro. Our results support the potential of EBV-miR-BHRF1-1 as a therapeutic target in EBV-associated CLL with p53 gene aberration.

Improvement of Poly(γ-glutamic acid) Biosynthesis and Quantitative Metabolic Flux Analysis of a Two-stage Strategy for Agitation Speed Control in the Culture of Bacillus subtilis NX-2

Dan Zhang,Zongqi Xu,Hong Xu,Xiaohai Feng,Sha Li,Heng Cai,Yan Wei,Pingkai Ouyang 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.6

In this study, the production of poly(γ-glutamic acid) by Bacillus subtilis NX-2 (PGA) at different agitation speeds was investigated. Based on the analysis of specific cell growth rate (μ) and specific PGA formation rate (q_p),a two-stage strategy for agitation speed control was proposed. During the first 24 h, an agitation speed of 600rpm was used to maintain a high μ for better cell growth,which then reduced to 400 rpm after 24 h to maintain a high qp to enhance PGA production. Using this method, the maximum concentration of PGA reached 40.5 ± 0.91 g/L and the PGA productivity was 0.56 ± 0.012 g/L/h, which was 17.7 and 9.8% higher, respectively, than the best results obtained when a constant agitation speed was used. The flux distributions and the related enzymes of 2-oxoglutarate could be affected by this two-stage strategy for agitation speed. The activity of isocitrate dehydrogenase and glutamate dehydrogenase at the key node of 2-oxoglutarate increased, and more flux distribution was directed to glutamate. The flux distribution from extracellular to intracellular glutamate also increased and improved PGA production as the glutamate uptake rates increased using the agitation-shift control method.

Surface Display of the HPV L1 Capsid Protein by the Autotransporter Shigella IcsA

Dan Xu,Xiaofeng Yang,Depu Wang,Jun Yu,Yili Wang 한국미생물학회 2014 The journal of microbiology Vol.52 No.1

Autotransporters have become attractive tools for surface expression of foreign proteins in Gram-negative bacteria. In this study, the Shigella autotransporter IcsA, has been exploited to express the human papillomavirus (HPV) type 16 L1 capsid protein in Shigella sonnei and Escherichia coli. The L1 gene was fused in-frame to replace the coding sequence of the IcsA passenger domain that is responsible for actin-based motility. The resultant hybrid protein could be detected by an anti-L1 antibody on the surface of S. sonnei and E. coli. In E. coli, the protein was expressed on the entire surface of the bacterium. In contrast, the protein was detected mainly at one pole of the Shigella bacterium. However, the protein became evenly distributed on the surface of the Shigella bacterium when the icsP gene was removed. Our study demonstrated the possibility of exploiting autotransporters for surface expression of large, heterologous viral proteins,which may be a useful strategy for vaccine development.

Development and Evaluation of a Duplex Real-Time PCR Assay With a Novel Internal Standard for Precise Quantification of Plasma DNA

Dan Chen,Shi-yang Pan,Erfu Xie,Li Gao,Huaguo Xu,Wenying Xia,Ting Xu,Peijun Huang 대한진단검사의학회 2017 Annals of Laboratory Medicine Vol.37 No.1

Background: Circulating levels of cell-free DNA increase in many pathologic conditions. However, notable discrepancies in the quantitative analysis of cell-free DNA from a large number of laboratories have become a considerable pitfall, hampering its clinical application. Methods: We designed a novel recombinant DNA fragment that could be applied as an internal standard in a newly developed and validated duplex real-time PCR assay for the quantitative analysis of total cell-free plasma DNA, which was tested in 5,442 healthy adults and 200 trauma patients. Results: Compared with two traditional methods, this novel assay showed a lower detection limit of 0.1 ng/mL, lower intra- and inter-assay CVs, and higher accuracy in the recovery test. The median plasma DNA concentration of healthy males (20.3 ng/mL, n=3,092) was significantly higher than that of healthy females (16.1 ng/mL, n=2,350) (Mann-Whitney two-sample rank sum test, P<0.0001). The reference intervals of plasma DNA concentration were 0-45.8 ng/mL and 0-52.5 ng/mL for healthy females and males, respectively. The plasma DNA concentrations of the majority of trauma patients (96%) were higher than the upper normal cutoff values and were closely related to the corresponding injury severity scores (R2=0.916, P<0.0001). Conclusions: This duplex real-time PCR assay with a new internal standard could eliminate variation and allow for more sensitive, repeatable, accurate, and stable quantitative measurements of plasma DNA, showing promising application in clinical diagnosis.