http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
The extract of natural plant promotes the proliferation of murine spermatogonial stem cells
Hye-Ryeon Kang,Yong-Hee Kim,Dong-Gu Lee,Ki-Jung Kim,Polash Chandra Karmakar,Hyun-Gu Kang,Sang-Eun Jung,Myeong-Geun Oh,Yeon-Jim Cho,Yu-Ri Choi,Chan Kyu Han,Sanghyung Lee,Buom-Yong Ryu 한국발생생물학회 2015 한국발생생물학회 학술발표대회 Vol.2015 No.9
The aim of this study was to enhance the proliferation efficiency of spermatogonial stem cells (SSCs). In order to improve the proliferation efficiency, we investigated new factors that promote the proliferation of SSCs using in vitro culture method with natural plant extracts. Germ cell populations containing SSCs were collected 6- to 8-days-old from C57BL/6-TG-EGFP (C57GFP) mice and SSCs were isolated from the collected cells via magnetic-activated cell sorting (MACS). Since then, SSCs were cultured for a week with culture medium containing natural plant extracts at concentration of 0.1, 1, and 10 μg/mL. After a week of culture, we looked for an increase, especially a dose-dependent increase, in the number of cells compared to that of the control group. A dose-dependent increase, in the number of cells was observed in the Petasides japonicus-treated groups. Furthermore, we carried out repeated experiment that is process consisting of selection and additional segmentation to explore new factors for activating SSCs at the molecular level. As a results, Petasides japonicus butanol fraction significantly increased the proliferation rate of SSCs in a dose-dependent manner among Petasides japonicus fraction samples. We identified normal expression level of PLZF in SSCs cultured with plant extracts using immunocytochemistry method. Furthermore, we also carried out qRT-PCR and identified normal expression level of Lhx1 and GFRα1. The finding of this study could contribute to improvement of proliferation and activation for SSCs, using culture method with natural plant extracts.
Types of 23S Ribosomal RNA Point Mutations and Therapeutic Outcomes for Helicobacter pylori
( Sang Yoon Kim ),( Jae Myung Park ),( Chul-hyun Lim ),( Hye Ah Lee ),( Ga-yeong Shin ),( Younghee Choe ),( Yu Kyung Cho ),( Myung-gyu Choi ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2021 Gut and Liver Vol.15 No.4
Background/Aims: Point mutations in the 23S ribosomal RNA gene have been associated with Helicobacter pylori clarithromycin resistance. This study aimed to detect the prevalence of these point mutations and to investigate the role of different point mutations in the success of eradication therapy. Methods: We retrospectively investigated a total of 464 consecutive patients who underwent an endoscopic examination and dual-priming oligonucleotide-based multiplex polymerase chain reaction for H. pylori between June 2014 and October 2019. For 289 patients with negative point mutations, standard triple therapy was used in 287 patients, and the bismuth-quadruple regimen was used in two patients. For 175 patients with positive point mutations (A2142G, A2143G, and both mutations), standard triple and bismuth-quadruple therapies were used in 37 patients and 138 patients, respectively. Results: The eradication rates of standard triple and bismuth-quadruple therapies showed no significant difference in mutation-negative patients or those with the A2142G point mutation. However, the eradication rate with bismuth-quadruple therapy was significantly higher than that with standard triple therapy in the group with the A2143G mutation or with the double mutation. The eradication rates for standard triple and bismuth-quadruple therapies, respectively, were 25.8% and 92.1% in the per-protocol group (p<0.001) and 24.2% and 85.2% in the intention-totreat analysis (p<0.001). Conclusions: The A2143G point mutation is the most prevalent cause of clarithromycin resistance. Bismuth-quadruple therapy is superior to standard triple therapy in patients with the A2143G or double point mutation. (Gut Liver 2021;15:528-536)
Induction of REDD1 <i>via</i> AP-1 prevents oxidative stress-mediated injury in hepatocytes
Cho, Sam Seok,Kim, Kyu Min,Yang, Ji Hye,Kim, Ji Young,Park, Su Jung,Kim, Seung Jung,Kim, Jae Kwang,Cho, Il Je,Ki, Sung Hwan Elsevier 2018 FREE RADICAL BIOLOGY AND MEDICINE Vol.124 No.-
<P><B>Abstract</B></P> <P>Regulated in development and DNA damage responses 1 (REDD1) is an inducible gene in response to various stresses, which functions as a negative regulator of the mammalian target of rapamycin protein kinase in complex 1. In the present study, we identified the role of REDD1 under the oxidative stress-mediated hepatocyte injury and its regulatory mechanism. REDD1 protein was increased in H<SUB>2</SUB>O<SUB>2</SUB> or <I>tert</I>-butylhydroperoxide (t-BHP)-treated hepatocytes<SUB>·</SUB> H<SUB>2</SUB>O<SUB>2</SUB> also elevated REDD1 mRNA levels. This event was inhibited by antioxidants such as diphenyleneiodonium chloride, <I>N</I>-acetyl-<SMALL>L</SMALL>-cysteine, or butylated hydroxy anisole. Interestingly, we found that H<SUB>2</SUB>O<SUB>2</SUB>-mediated REDD1 induction was transcriptionally regulated by activator protein-1 (AP-1), and that overexpression of c-Jun increased REDD1 protein levels and REDD1 promoter-driven luciferase activity. Deletion of the putative AP-1 binding site in proximal region of the human <I>REDD1</I> promoter significantly abolished REDD1 transactivation by c-Jun. A NF-E2-related factor 2 activator, <I>tert</I>-butylhydroquinone treatment also elevated REDD1 levels, but it was independent on NF-E2-related factor 2 activation. Furthermore, we observed that REDD1 overexpression attenuated H<SUB>2</SUB>O<SUB>2</SUB> or t-BHP-derived reactive oxygen species formation as well as cytotoxicity. Conversely, siRNA against REDD1 aggravated t-BHP-induced reactive oxygen species generation and cell death. In addition, we showed that REDD1 was induced by <I>in vitro</I> or <I>in vivo</I> ischemia/reperfusion model. Our results demonstrate that REDD1 induction by oxidative stress is mainly transcriptionally regulated by AP-1, and protects oxidative stress-mediated hepatocyte injury. These findings suggest REDD1 as a novel molecule that reduced susceptibility to oxidant-induced liver injury.</P> <P><B>Highlights</B></P> <P> <UL> <LI> REDD1 was enhanced in response to oxidative stress. </LI> <LI> AP-1 site from − 644 to − 638 bp in human <I>REDD1</I> was critical for gene expression. </LI> <LI> REDD1 protects cells against ROS in hepatocytes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Bioinspired tuning of glycol chitosan for 3D cell culture
Cho, Myeong Ok,Li, Zhengzheng,Shim, Hye-Eun,Cho, Ik-Sung,Nurunnabi, Md,Park, Honghyun,Lee, Kuen Yong,Moon, Sung-Hwan,Kim, Ki-Suk,Kang, Sun-Woong,Huh, Kang Moo Nature Publishing Group 2016 NPG Asia Materials Vol.8 No.-
<P>Three-dimensional (3D) cell culture systems have promising applications compared with conventional two-dimensional cell culture systems. Herein, we report a facile method for the formation of 3D spheroids using novel thermo-reversible polysaccharide-based hydrogels. A series of thermo-reversible hydrogels consisting of N-acyl glycol chitosans (NAGCs) are synthesized through a simple N-acylation reaction, and the degree of acylation is finely tuned to obtain adequate thermo-reversible properties and gel stability. Among the NAGCs, N-hexanoyl glycol chitosan is the most thermo-sensitive and is highly effective for forming multi-cellular spheroids when used to coat the surfaces of cell culture dishes. Cell spheroids are effectively formed at various cell concentrations, and their spheroid shape and cellular functions are well maintained for longer times. The hydrogel culture system is also useful for co-cultures that mimic a biological microenvironment. Our thermo-reversible hydrogels may offer a convenient method for the development of in vitro 3D cell culture systems to provide enhanced performance in tissue regeneration, organ-on-chips, drug screening research and other biomedical applications.</P>
Cho, Young Hye,Lee, Sang Yeoup,Kim, Cheol Min,Kim, Nam Deuk,Choe, Sangmin,Lee, Chang-Hyung,Shin, Jin-Hong Hindawi Publishing Corporation 2016 Evidence-based Complementary and Alternative Medic Vol.2016 No.-
<P>Ursolic acid (UA) is the major active component of the loquat leaf extract (LLE) and several previous studies have indicated that UA may have the ability to prevent skeletal muscle atrophy. Therefore, we conducted a randomized, double-blind, and placebo-controlled study to investigate the effects of the LLE on muscle strength, muscle mass, muscle function, and metabolic markers in healthy adults; the safety of the compound was also evaluated. We examined the peak torque/body weight at 60°/s knee extension, handgrip strength, skeletal muscle mass, physical performance, and metabolic parameters at baseline, as well as after 4 and 12 weeks of intervention. Either 500 mg of LLE (50.94 mg of UA) or a placebo was administered to fifty-four healthy adults each day for 12 weeks; no differences in muscle strength, muscle mass, and physical performance were observed between the two groups. However, the right-handgrip strength of female subjects in the LLE group was found to be significantly better than that of subjects in the control group (<I>P</I> = 0.047). Further studies are required to determine the optimal dose and duration of LLE supplementation to confirm the first-stage study results for clinical application. ClinicalTrials.gov Identifier is NCT02401113.</P>
( Hye Yon Cho ),( Sung Ho Park ),( Hong Bae Kim ) 대한산부인과학회 2010 Journal of Womens Medicine Vol.3 No.1
Vaginal evisceration with abdominal viscera following hysterectomy is very uncommon complication. However, total laparoscopic hysterectomy (TLH) seems to be higher risk than other hysterectomy routes. Minimizing the use of electrothermal instruments and meticulous, full-thickness closure during vaginal vault procedure in TLH will decrease the risk. But if a vaginal vault prolapse occurs unfortunately, a delayed absorbable polydioxanone suture like PDS will be benefit in closing vaginal vault. In most of these cases, healing of vaginal vault is good by one time of repair and recurrence is rare. We experience a case of 48-year-old woman who presented repetitive vaginal evisceration after TLH. Therefore, we report this case with relevant literatures. Surgeons should consider advising women who underwent TLH regarding the slow and steady resumption of the first sexual intercourse postoperatively, particularly patients having highly sexual activity and high risk of wound-healing.
Adaptive Voltage-Controlled Oscillator for Improved Dynamic Performance in LLC Resonant Converter
Sang-Woo Kang,Hye-Jin Kim,Bo-Hyung Cho IEEE 2016 IEEE transactions on industry applications Vol.52 No.2
<P>This paper proposes an adaptive voltage-controlled oscillator (VCO) to improve the dynamic performance in LLC resonant converters. The proposed adaptive VCO is designed to have frequency-dependent small-signal gains, so that the variation of low-frequency magnitude in frequency response of LLC resonant converter is effectively adjusted. As a result, an enhanced dynamic performance is obtained over wide-operating ranges. Through approximated derivation, the proposed adaptive VCO has a simple formula and does not require any additional sensing circuits. Furthermore, it is robust to variation of circuit parameters. Dynamic performance enhancement was verified by experimental results with a 144-W laboratory prototype half-bridge LLC resonant converter.</P>
Validation and Determination of the Contents of Acetaldehyde and Formaldehyde in Foods
Hye-Seung Jeong,Hyun Chung,Sang-Hoon Song,Cho-Il Kim,Joon-Goo Lee,Young-Suk Kim 한국독성학회 2015 Toxicological Research Vol.31 No.3
The aim of this study was to develop an efficient quantitative method for the determination of acetaldehyde (AA) and formaldehyde (FA) contents in solid and liquid food matrices. The determination of those compounds was validated and performed using gas chromatography-mass spectrometry combined by solid phase micro-extraction after derivatization with O-(2,3,4,5,6-pentafluoro-benzyl)-hydroxylamine hydrochloride. Validation was carried out in terms of limit of detection, limit of quantitation, linearity, precision, and recovery. Then their contents were analyzed in various food samples including 15 fruits, 22 milk products, 31 alcohol-free beverages, and 13 alcoholic beverages. The highest contents of AA and FA were determined in a white wine (40,607.02 ng/g) and an instant coffee (1,522.46 ng/g), respectively.