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( Ji Young Kim ),( Chang Wook Kim ),( Yun Hui Kim ),( Seok Cheon Yeom ),( Su Gyeong Lee ),( Hee Yeon Kim ),( Si Hyun Bae ),( Jong Young Choi ),( Seung Kew Yoon ) 대한간학회 2016 춘·추계 학술대회 (KASL) Vol.2016 No.1
Aims: Immune regulatory molecules such as forkhead box P3 (Foxp3) on CD4+ T cell and cytotoxic T lymphocyte-associated antigen 4 CTLA-4) on CD8+ T cell are associated with antiviral effector T cell dysfunction, which influences on T cell exhaustion and persistent viral infection in patients with chronic hepatitis B. These Foxp3 and CTLA-4 are up-regulated in chronic hepatitis B. During antiviral therapy with tenofovir, the expressions of Foxp3 and CTLA-4 could be changed. We investigated the relationship between antiviral effects of tenofovir and the expression of Foxp3 and CTLA-4 during tenofovir treatment in chronic hepatitis B. Methods: Eight patients with chronic hepatitis B under tenofovir treatment were enrolled for detection of Foxp3 on CD4+ T cell and CTLA-4 on CD8+ T cell. Peripheral blood mononuclear cells were isolated from these subjects before tenofovir treatment (T0), 3 month (T3) and 6 month (T6) during tenofovir treatment. For antiviral effect analysis, serum HBV DNA levels were checked at same time. The expressions of Foxp3 and CTLA-4 on T cells were monitored by flow cytometry. Results: Three patients (3 of 8) showed marked decreases of Foxp3 and CTLA-4 during tenofovir therapy (group 1). Five patients (5 of 8) showed minimal changes of Foxp3 or CTLA-4 during tenofovir therapy (group 2). Group 1 showed complete virologic response within 6 month therapy regardless of baseline HBV DNA level but, group 2 showed complete virologic response within 6 month therapy only in patients with low baseline HBV DNA level (< 7log HBV DNA). Conclusions: Among the patients with chronic hepatitis B, the patients who showed marked decrease of Foxp3 and CTLA-4 during tenofovir therapy are associated with strong antiviral effects of tenofovir regardless of baseline HBV DNA level. This finding suggests that restoration of HBV-specific T cell strengthens the antiviral effects of tenofovir.
Yoon-Hyuck Chang(장윤혁),Joong-Hyun Yeom(염중현),Kyung-Hwan Jung(정경환),Byung Chul Chang(장병철),Jung Hee Shin(신정희),Sun-Kyun Yoo(유선균) 한국생명과학회 2009 생명과학회지 Vol.19 No.4
본 연구는 Lipomyces starkeyi KCTC 17343에 의한 dextranase 최적 생산 조건을 확립하고 dextran에 대한 효소분해 특성을 규명하였다. 균주의 성장과 dextranase생산은 발효초기 pH와 온도에 따라 다르며 최적 pH는 4-5, 최적온도는 25-30℃의 범위에서 결정이 되었다. 최적 발효조건에서의 dextranase 생산은 total enzyme activity가 4.85 IU/㎖으로 나타났다. 이때의 발효균주의 specific growth rate는 0.076h?¹이었다. 발효 중 dextranase의 활성은 발효 정상기에서도 안정성을 유지하였다. Dextranase에 의한 dextran을 가수분해 결과, 가수분해물의 구성은 DP2 to 8에 이르는 올리고 덱스트란으로 이루어졌다. We optimized dextranase culture conditions by batch fermentation using Lipomyces starkeyi KCTC 17343. Furthermore, dextranase was purified by an ultra-membrane, and then dextran hydrolyzates were characterized. Cell growth and dextranase production varied depending on the initial culture pH and temperature. The conditions of optimal dextranase production were met in a pH range of 4-5 and temperature between 25-30℃. At optimal fermentation conditions, total enzyme activity and specific enzyme activity were about 4.85 IU/㎖ and 0.79 IU/g cells, respectively. The specific growth rate was examined to be 0.076 hr-¹. The production of dextranase in culture broth was very stably maintained after mid-log phase of growth. The enzyme hydrolyzed dextran into DP (degree of polymerization) 2 to 8 oligodextran series. Analysis of the composition of hydrolysates suggested that the enzyme produced is an endo-dextranase.
Yoon, Ho Yub,Kwak, Seong Shin,Jang, Moon Ho,Kang, Min Hyung,Sung, Si Woo,Kim, Chang Hyun,Kim, Sung Rae,Yeom, Dong Woo,Kang, Myung Joo,Choi, Young Wook Elsevier 2017 International journal of pharmaceutics Vol.523 No.1
<P><B>Abstract</B></P> <P>We previously synthesized the RIPL peptide (IPLVVPLRRRRRRRRC) to facilitate selective delivery into hepsin-expressing cancer cells and showed that RIPL peptide-conjugated liposomes (RIPL-L) enhanced the intracellular delivery of fluorescent probes <I>in vitro</I>. In this study, docetaxel-loaded RIPL-L (DTX-RIPL-L) were prepared and evaluated for <I>in vitro</I> drug release, cytotoxicity, and <I>in vivo</I> antitumor efficacy. DTX was successfully encapsulated by pre-loading, with an average encapsulation efficiency and drug loading capacity of 32.4% and 21.39±2.05 (μg/mg), respectively. A DTX release study using dialysis showed a biphasic release pattern, i.e., rapid release for 6h, followed by sustained release up to 72h. The first-order equation provided the best fit for drug release (r<SUP>2</SUP> =0.9349). <I>In vitro</I> cytotoxicity was dose-dependent, resulting in IC<SUB>50</SUB> values of 36.10 (SK-OV-3) and 48.62ng/mL (MCF-7) for hepsin-positive, and 61.12 (DU145) and 53.04ng/mL (PC-3) for hepsin-negative cell lines. Live/dead cell imaging was carried out to visualize the proportion of viable and nonviable SK-OV-3 cells. Compared to DTX solution, DTX-RIPL-L significantly inhibited tumor growth and prolonged survival time in BALB/c nude mice with SK-OV-3 cell tumors. We suggest that DTX-RIPL-L is a good candidate for efficient drug targeting to hepsin-expressing cancer cells.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Yeom, Ji-Ran,Yoon, Soon-Uk,Kim, Chang-Gyun Elsevier 2017 CHEMOSPHERE - Vol.182 No.-
<P><B>Abstract</B></P> <P>Antibiotic resistant bacteria (ARB) in livestock manure used as fertilizer and spread over agriculture land, may pose a threat to the health of humans. Considering this, the concentrations of tetracycline (TC), oxytetracycline (OTC), and sulfathiazole (STZ) in the surface soil were quantified using LC-MS. These antibiotics have been used in livestock and are found in fertilizer produced from livestock excretions. Species of ABR were identified using 16S rDNA. Soil samples were collected at depths of 0, 7, and 15 cm from farmland in Incheon (South Korea). In the surface soil, three compounds were detected: TC (17.74 μg/kg), OTC (0.78 μg/kg), and STZ (0.23 μg/kg). However, except for STZ, antibiotics were not detected in the deeper samples. Overall, TC can form a chelated complex with cations, which consequently enhances its adsorption to the organic matter and metals in soil. This property can significantly reduce the mobility of TC (to lower than that of STZ). The result of 16S rDNA gene analysis indicated that <I>Pseudomonas</I> spp., <I>Arthrobacter</I> spp., and <I>Rhodococcus</I> spp. showed persistent resistance to the three antibiotics tested. DNA quantification results revealed strong resistance of <I>Pseudomonas</I> spp. to STZ, whereas <I>Arthrobacter</I> spp. and <I>Rhodococcus</I> spp. had resistance to TC and OTC. Antibiotics biodegradation suggested ability of ARB to grow in soil samples in presence of residual antibiotics during 13 days incubation. The concentrations of STZ, TC, and OTC reduced as much as 23.53, 35.60 and 66.88%, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> TC (17.74 μg/kg), OTC (0.78 μg/kg), STZ (0.23 μg/kg) were detected in the topmost soil (collected at ground surface). </LI> <LI> <I>Pseudomonas</I> spp., <I>Arthrobacter</I> spp. and <I>Rhodococcus</I> spp. had persistent resistance to the 3 antibiotics tested by 16s rDNA. </LI> <LI> <I>Pseudomonas</I> spp. showed strong resistance to STZ, and <I>Arthrobacter</I> spp. and <I>Rhodococcus</I> spp. to TC and OTC by RT-qPCR. </LI> <LI> The concentrations of STZ, TC, and OTC degraded by ARB respectively dropped to 23.53%, 35.60% and 66.88%. </LI> </UL> </P>
室內培養에 의한 Cosmarium laeve Rabenhorst와 C. subprotumidum var. gregorii(Roy et Biss.) West et West의 形態變異
염청미,張允卿 숙명여자대학교 자연과학연구소 1989 자연과학논문집 Vol.- No.1
한국산 Cosmarium 속의 종 분류학적 연구를 위하여 1985년 3월부터 1986년 9월까지 경기도 부근에서 Cosmarium laeve Rabenhorst와 Cosmarium subprotumidum var. gregorii(Roy et Biss.) West et West의 2 strain을 채집 분리하였다. 실내 배양을 통해 Cosmarium 속 식물의 세포 형태, 크기 및 세포벽의 구조를 비교 고찰하였다. aging에 따른 관찰 결과 C.laeve는 세포의 크기와 형태에 변이폭이 심해 janus type과 C. laeve var. depressum type의 형태가 유도되었으며, 2배체로 여겨지는 대형 세포도 관찰되었다. C.subprotumidum var. gregorii는 세포벽 과립의 약화로 인해 기본종에 수렴하는 세포형태를 보였다. 또한 대형세포로서 크기가 증가한 세포와 극면이 삼각형인 세포가 나타남으로써 매우 변이가 심한 종으로 간주되었다. Two strains of Cosmarium species, C. laeve Rabenhorst and C. subprotumidum var. gregorii(Roy et Biss.) West et West were isolated from two ponds in Kyunggi-Do for taxonomical study. The isolates were cultured in laboratory to observe variations in cell shape, size and wall structure. Both isolates were proved to be morphologically quite variable when studied under laboratory conditions. In the stationary culture of C. laeve we could find janus type and C. laeve var. depressum type along with giant cells which are considered to be diploid. Three radiate staurastrum type and C. ubprotumidum type were found in the stationary culture of C. subprotumidum var.gregorii.
Investigation of a four-wave mixing signal generated in fiber-delivered CARS microscopy
Jun, Chang Su,Kim, Byoung Yoon,Park, Ju Hyun,Lee, Jae Yong,Lee, Eun Seong,Yeom, Dong-Il The Optical Society 2010 Applied Optics Vol.49 No.20
<P>We studied the nonlinear signal generated in the fiber at an anti-Stokes wavelength during the delivery of the picosecond (ps) pump and Stokes beams in coherent anti-Stokes Raman scattering (CARS) microscopy. A small non-phase-matched four-wave mixing (FWM) signal was prevalently observed in the fiber at the power level where other nonlinear processes, including self-phase modulation and cross-phase modulation, were well suppressed. We analyzed the features of the FWM signal generation by varying the location of temporal overlap between two input pulses in the fiber to compare this to the CARS signal generated in the sample. Numerical modeling based on the nonlinear Schrödinger equation was also conducted and clearly explains the results in the experiment. In addition, we experimentally verified the interferometric feature of this FWM signal with the CARS signal by employing a phase-shifting unit, which potentially suggests the use of the FWM signal as a local oscillator for the interferometric CARS system.</P>