Effects of Lactobacillus salivarius Ren on cancer prevention and intestinal microbiota in 1, 2-dimethylhydrazine-induced rat model

Ming Zhang,Xing Fan,Bing Fang,Chengzhen Zhu,Jun Zhu,Fazheng Ren 한국미생물학회 2015 The journal of microbiology Vol.53 No.6

Probiotics have been suggested as a prophylactic measure in colon cancer. The aim of this study was to investigate the impact of Lactobacillus salivarius Ren (Ren) in modulating colonic microbiota structure and colon cancer incidence in a rat model after injection with 1,2-dimethyl hydrazine (DMH). The results indicated that oral administration of Ren could effectively suppress DMH-induced colonic carcinogenesis. A significant decrease in cancer incidence (87.5% to 25%) was detected in rats fed with a dose of 5 × 1010 CFU/kg bodyweight per day. Using denaturing gradient gel electrophoresis and Real-time PCR combined with multivariate statistical methods, we demonstrated that injection with DMH significantly altered the rat gut microbiota, while Ren counteracted these DMH-induced adverse effects and promoted reversion of the gut microbiota close to the healthy state. Tvalue biplots followed by band sequencing identified 21 bacterial strains as critical variables affected by DMH and Ren. Injection of DMH significantly increased the amount of Ruminococcus species (sp.) and Clostridiales bacteria, as well as decreasing the Prevotella sp. Administration of Ren reduced the amount of Ruminococcus sp., Clostridiales bacteria, and Bacteroides dorei, and increased the amount of Prevotella. Real-time PCR results were consistent with the results derived by t-value biplots. These findings suggested that Ren is a potential agent for colon cancer prevention. In conclusion, the results in the present study suggest a potential therapeutic approach based on the modulation of intestinal microflora by probiotics may be beneficial in the prevention of colorectal carcinogenesis.

Association of MDR1 Gene Polymorphisms with Susceptibility to Hepatocellular Carcinoma in the Chinese Population

Ren, Yong-Qiang,Han, Ju-Qiang,Cao, Jian-Biao,Li, Shao-Xiang,Fan, Gong-Ren Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Objective: The objective of this study was to evaluate the association of MDR1 gene polymorphisms with susceptibility to hepatocellular carcinoma (HCC). Methods: A total of 689 HCC patients and 680 cancer-free subjects were enrolled. Human MDR1 gene polymorphisms were investigated by created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods. Multiple logistic regression models were applied to estimate the association between MDR1 gene polymorphisms and susceptibility to HCC. Results: We detected a novel c.4125A>C polymorphism and our findings suggested that this variant was significantly associated with susceptibility to HCC. A significantly increased susceptibility to HCC was noted in the homozygote comparison (CC versus AA: OR=1.621, 95% CI 1.143-2.300, ${\chi}^2$=7.4095, P=0.0065), recessive model (CC versus AC+AA: OR=1.625, 95% CI 1.167-2.264, ${\chi}^2$=8.3544, P=0.0039) and allele contrast (C versus A: OR=1.185, 95% CI 1.011-1.389, ${\chi}^2$=4.4046, P=0.0358). However, no significant increase was observed in the heterozygote comparison (AC versus AA: OR=0.995, 95% CI 0.794-1.248, ${\chi}^2$=0.0017, P=0.9672) and dominant model (CC+AC versus AA: OR=1.106, 95% CI 0.894-1.369, ${\chi}^2$=0.8560, P=0.3549). Conclusions: These findings suggest that the c.4125A>C polymorphism of the MDR1 gene might contribute to susceptibility to HCC in the Chinese population. Further work will be necessary to clarify the relationship between the c.4125A>C polymorphism and susceptibility to HCC on larger populations of diverse ethnicity.

CHARGE TRANSPORT THROUGH CARBON NANOTUBE OR FULLERENE–MOLECULE–SILICON JUNCTIONS

FU-REN F. FAN,BO CHEN,AUSTEN K. FLATT,JAMES M. TOUR,ALLEN J. BARD 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2007 NANO Vol.2 No.5

We report here the current–voltage (i–V) characteristics of several (n++-Si/MNOPE/C60/Pt-tip) or (n++-Si/MNOPE/SWCNT/Pt-tip) junctions, where MNOPE = 2'-mononitro-4, 4'-bis(phenylethynyl)-1-phenylenediazonium and SWCNT = single wall carbon nanotube. A layer of C60 or SWCNT-derivatized MNOPE has strong effect on the i–V behavior of the junctions, including rectification, negative differential resistance (NDR) and switching behaviors. The i–V curve of a grafted molecular monolayer (GMM) of MNOPE atop n++-Si shows NDR behavior, whereas those of C60- and SWCNT-derivatized GMMs of MNOPE on n++-Si show strong rectifying behavior with opposite rectification polarities. With C60, larger currents were found with negative tip bias, while with SWCNT, the forward top bias was positive. Because C60 tends to be a good electron acceptor and SWCNTs tend to be good electron donors, they show different i–V behavior, as observed. Some of the (n++-Si/MNOPE/SWCNT/Pt-tip) junctions also show reversible bistable switching behavior.

Sensorless PMSM Control with Sliding Mode Observer Based on Sigmoid Function

Ren Ningning,Fan Le,Zhang Zan 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.2

It is impossible to install or apply position sensors appropriately in some special applications of PMSM. Sensorless PMSM control is an appropriate choice to solve some problems in the control of PMSM. It is necessary to acquire an estimated position precisely and avoid the chattering phenomenon for sensorless PMSM control. This paper proposes an algorithm for estimating position with sliding mode observer (SMO) based on sigmoid function, and a suffi cient condition that leads SMO into a sliding surface is acquired using Lyapunov stabilization analysis. The outcome of this study shows that SMO based on sigmoid function for sensorless PMSM control can estimate position with high precision and avoid chattering phenomenon under the condition of diff erent velocity and load. However, the estimated position needs to be compensated for according to load, and the compensating value is in proportion to the value of the current.

Rodent peri-implantitis models: a systematic review and meta-analysis of morphological changes

Ren Jie Jacob Chew,Jacinta Xiaotong Lu,Yu Fan Sim,Alvin Boon Keng Yeo 대한치주과학회 2022 Journal of Periodontal & Implant Science Vol.52 No.6

Purpose: Rodent models have emerged as an alternative to established larger animal models for peri-implantitis research. However, the construct validity of rodent models is controversial due to a lack of consensus regarding their histological, morphological, and biochemical characteristics. This systematic review sought to validate rodent models by characterizing their morphological changes, particularly marginal bone loss (MBL), a hallmark of peri-implantitis. Methods: This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A literature search was performed electronically using MEDLINE (PubMed), and Embase, identifying pre-clinical studies reporting MBL after experimental peri-implantitis induction in rodents. Each study’s risk of bias was assessed using the Systematic Review Center for Laboratory animal Experimentation (SYRCLE) risk of bias tool. A meta-analysis was performed for the difference in MBL, comparing healthy implants to those with experimental peri-implantitis. Results: Of the 1,014 unique records retrieved, 23 studies that met the eligibility criteria were included. Peri-implantitis was induced using 4 methods: ligatures, lipopolysaccharide, microbial infection, and titanium particles. Studies presented high to unclear risks of bias. During the osseointegration phase, 11.6% and 6.4%-11.3% of implants inserted in mice and rats, respectively, had failed to osseointegrate. Twelve studies were included in the meta-analysis of the linear MBL measured using micro-computed tomography. Following experimental peri-implantitis, the MBL was estimated to be 0.25 mm (95% confidence interval [CI], 0.14–0.36 mm) in mice and 0.26 mm (95% CI, 0.19–0.34 mm) in rats. The resulting peri-implant MBL was circumferential, consisting of supra- and infrabony components. Conclusions: Experimental peri-implantitis in rodent models results in circumferential MBL, with morphology consistent with the clinical presentation of peri-implantitis. While rodent models are promising, there is still a need to further characterize their healing potentials, standardize experiment protocols, and improve the reporting of results and methodology.

Sp1-Induced SETDB1 Overexpression Transcriptionally Inhibits HPGD in a β-Catenin-Dependent Manner and Promotes the Proliferation and Metastasis of Gastric Cancer

Fan, Yaguan,Yang, Libo,Ren, Yi,Wu, Yunhua,Li, Linhai,Li, Lihua The Korean Gastric Cancer Association 2022 Journal of gastric cancer Vol.22 No.-

Purpose: Gastric cancer (GC) has high morbidity and mortality, the cure rate of surgical treatment and drug chemotherapy is not ideal. Therefore, development of new treatment strategies is necessary. We aimed to identify the mechanism underlying Sp1 regulation of GC progression. Methods and Methods: The levels of Sp1, β-catenin, SET domain bifurcated 1 (SETDB1), and 15-hydroxyprostaglandin dehydrogenase (HPGD) were detected by quantitative reverse transcription polymerase chain reaction and western blot analysis. The targets of SETDB1 were predicted by AnimalTFDB, and dual-luciferase reporter assay was used for confirming the combination of Sp1, β-catenin, and SETDB1. HGC27 or AGS cells (1×10⁶ cells/mouse) were injected into mice via the caudal vein for GC model establishment. The level of Ki67 was detected using immunohistochemistry, and hematoxylin and eosin staining was performed for evaluating tumor metastasis in mice with GC. Results: HPGD was inhibited, while the protein levels of Sp1, β-catenin, and SETDB1 were up-regulated in GC tissues and cell lines. HPGD overexpression or SETDB1 silencing inhibited the proliferation, invasion, and migration of GC cells, and Sp1 regulated the proliferation, invasion, and migration of GC cells in a β-catenin-dependent manner. Furthermore, HPGD served as a target of SETDB1, and it was negatively regulated by SETDB1; additionally, Sp1 and β-catenin bound to the SETDB1 promoter and negatively regulated HPGD expression. We proved that Sp1 regulated GC progression via the SETDB1/HPGD axis. Conclusions: Our findings revealed that Sp1 transcriptionally inhibited HPGD via SETDB1 in a β-catenin-dependent manner and promoted the proliferation and metastasis of GC cells.

Rodent peri-implantitis models: a systematic review and meta-analysis of morphological changes

Ren Jie Jacob Chew,Jacinta Xiaotong Lu,Yu Fan Sim,Alvin Boon Keng Yeo Korean Academy of Periodontology 2022 Journal of Periodontal & Implant Science Vol.52 No.6

Purpose: Rodent models have emerged as an alternative to established larger animal models for peri-implantitis research. However, the construct validity of rodent models is controversial due to a lack of consensus regarding their histological, morphological, and biochemical characteristics. This systematic review sought to validate rodent models by characterizing their morphological changes, particularly marginal bone loss (MBL), a hallmark of peri-implantitis. Methods: This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A literature search was performed electronically using MEDLINE (PubMed), and Embase, identifying pre-clinical studies reporting MBL after experimental peri-implantitis induction in rodents. Each study's risk of bias was assessed using the Systematic Review Center for Laboratory animal Experimentation (SYRCLE) risk of bias tool. A meta-analysis was performed for the difference in MBL, comparing healthy implants to those with experimental peri-implantitis. Results: Of the 1,014 unique records retrieved, 23 studies that met the eligibility criteria were included. Peri-implantitis was induced using 4 methods: ligatures, lipopolysaccharide, microbial infection, and titanium particles. Studies presented high to unclear risks of bias. During the osseointegration phase, 11.6% and 6.4%-11.3% of implants inserted in mice and rats, respectively, had failed to osseointegrate. Twelve studies were included in the meta-analysis of the linear MBL measured using micro-computed tomography. Following experimental peri-implantitis, the MBL was estimated to be 0.25 mm (95% confidence interval [CI], 0.14-0.36 mm) in mice and 0.26 mm (95% CI, 0.19-0.34 mm) in rats. The resulting peri-implant MBL was circumferential, consisting of supra- and infrabony components. Conclusions: Experimental peri-implantitis in rodent models results in circumferential MBL, with morphology consistent with the clinical presentation of peri-implantitis. While rodent models are promising, there is still a need to further characterize their healing potentials, standardize experiment protocols, and improve the reporting of results and methodology.

Fungichromin Production by Streptomyces padanus PMS-702 for Controlling Cucumber Downy Mildew

Fan, Ya-Ting,Chung, Kuang-Ren,Huang, Jenn-Wen The Korean Society of Plant Pathology 2019 Plant Pathology Journal Vol.35 No.4

Streptomyces padanus PMS-702 strain produces a polyene macrolide antibiotic fungichromin and displays antagonistic activities against many phytopathogenic fungi. In the present study, experimental formulations were assessed to improve the production of fungichromin, the efficacy of PMS-702 on the suppression of sporangial germination, and the reduction of cucumber downy mildew caused by Pseudoperonospora cubensis. PMS-702 strain cultured in a soybean meal-glucose (SMG) medium led to low levels of fungichromin accumulation and sporangial germination suppression. Increasing medium compositions and adding plant oils (noticeably coconut oil) in SMG significantly increased fungichromin production from 68 to $1,999.6{\mu}g/ml$. Microscopic examination reveals that the resultant suspensions significantly reduced sporangial germination and caused cytoplasmic aggregation. Greenhouse trials reveal that the application of PMS-702 cultural suspensions reduced downy mildew severity considerably. The addition of Tween 80 into the synthetic medium while culturing PMS-702 further increased the suppressive efficacy of downy mildew severity, particularly when applied at 24 h before inoculation or co-applied with inoculum. Fungichromin at $50{\mu}g/ml$ induced phytotoxicity showing minor necrosis surrounded with light yellowish halos on cucumber leaves. The concentration that leads to 90% inhibition (IC90) of sporangial germination was estimated to be around $10{\mu}g/ml$. The results provide a strong possibility of using the S. padanus PMS-702 strain as a biocontrol agent to control other plant pathogens.

Active Gate Charge Control Strategy for Series-Connected IGBTs

Fan Zhang,Yu Ren,Mofan Tian,Xu Yang 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Since the voltage blocking capability of a single insulated gate bipolar transistor (IGBT) is limited, series-connected IGBTs are used in power electronic converters to satisfy the requirements of high-power and high-voltage applications. However, due to the parameter differences of the series-connected IGBTs, it is difficult to ensure an equal voltage sharing between the devices during both transient and steady-state operations. This paper proposes a novel active gate drive which operates basing on the active gate charge control strategy. The proposed active gate drive is able to achieve both minimized power loss and proper voltage sharing between the series-connected IGBTs. The active gate charge control strategy has been validated by simulations, and promising results have been obtained.

Simulation of natural convection in an inclined polar cavity using a finite-difference lattice Boltzmann method

Fan Yang,Haicheng Yang,Yonghua Yan,Xueyan Guo,Ren Dai,Chaoqun Liu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.6

Natural convection heat transfer in an inclined polar cavity was studied using a Finite-difference lattice Boltzmann method (FDLBM)based on a double-population approach for body-fitted coordinates. A D2G9 model coupled with the simplest TD2Q4 lattice model wasapplied to determine the velocity field and temperature field. For both velocity and temperature fields, the discrete spatial derivativeswere obtained by combining the upwind scheme with the central scheme, and the discrete temporal term is obtained using a fourth-orderRunge-Kutta scheme. Studies were carried out for different Rayleigh numbers and different inclination angles. The results in terms ofstreamlines, isotherms, and Nusselt numbers explain the heat transfer mechanism of natural convection in an inclined polar cavity due tothe change of Rayleigh number and inclination angle.