Optimization of Human Interferon Gamma Production in Escherichia coli by Response Surface Methodology

Victor E. Balderas Hernandez,Luz M. T. Paz Maldonado,Emilio Medina Rivero,Ana P. Barba de la Rosa,Leandro G. Ordonez Acevedo,Antonio De Leon Rodriguez 한국생물공학회 2008 Biotechnology and Bioprocess Engineering Vol.13 No.1

The production of human interferon gamma (hIFN-γ) using a synthetic gene in Escherichia coli BL21-SI was optimized by response surface methodology (RSM) and a Box-Behnken design. The process variables studied were temperature, biomass concentration at induction time and the NaCl concentration as inducer. According to the Box-Behnken design, a second order response function was developed. The optimal expression conditions were a temperature of 32.6℃, induction biomass of 0.31 g/L and 0.3 M NaCl in minimal medium. The model prediction for the maximum hIFN-γ production was 77.3 mg/L, which corresponded satisfactorily with the experimental data. The hIFN-γ concentration attained under optimized conditions was 13-times higher than that obtained using the non-optimized conditions. We conclude that RSM is an effective method for the optimization of recombinant protein expression using synthetic genes in E. coli.

First Record of the Pacific Fanfish Pteraclis aesticola (Jordan and Snyder, 1901) in the Tropical Eastern Pacific

Aguero, Jose De La Cruz,Gomez, Victor Manuel Cota The Korean Society of Oceanography 2008 Ocean science journal Vol.43 No.3

One specimen of Pteraclis aesticola was collected off San Jose del Cabo, Baja California Sur, Mexico ($22^{\circ}54'N$, $109^{\circ}45'W$), in March 2007. Present record is the first reported occurrence of the species in the Tropical Eastern Pacific biogeographic region (Gulf of California to southern Ecuadorian waters). Its large fan-like anal and dorsal fins and its counts of fin rays and vertebrae can distinguish the Pacific fanfish from the other species in the genus. This fish may have not yet been recorded in the region because its presence has been overlooked in the past because of rarity and lack of commercial value.

中文教與學處理學生學習差異的原則和策略

Tse Shek Kam,Wong Man Ying,Laing Victor,Wu Kam Fong,Tsui Pik Fong,To Heiken,Lam Lu Sai 단국대학교 한문교육연구소 2020 International Han-character Education Research Vol.3 No.1

홍콩에는 예부터 지금까지 파키스탄, 인도, 네팔 등에서 온 이민들을 포함하여, 비중국어권 아동들이 적지 않다. 평등교육의 이념을 표방하는 홍콩평등기회위원회(香港平等機會委員會)는 비중국어권 학습자들이 중국어권 학습자들과 같은 학교에서 학습하기를 건의하여 그들이 최대한 빠른 시일 내에 홍콩 사회로 융화되게 하려 하였다. 이로 인해, 비중국어권 아동들은 홍콩 현지의 일반 유치원을 다니게 되었는데, 홍콩의 교육 관할 당국도 적지 않은 자원을 투입하여 이들이 현지 교육과정에 적응할 수 있도록 협조하였으나, 그 효과를 즉각적으로 확인할 수는 없었다. 그 중 가장 큰 문제는 학습의 차이를 처리하는 것이었다. 비중국어권 아동들의 중국어 실력은 모국어 수준에 미치지는 못했다. 이들이 중국어권 아동들과 함께 중국어 수업에 참여할 때 적잖은 어려움이 발행했다. 또한, 비중국어권 아동들의 성장 배경도 각기 달랐다. 신이민자 가정의 아동도 있고, 현지에서 출생한 소수 민족 아동도 있어, 이러한 학습자 사이의 중국어 수준의 차이도 존재했다. 이밖에도 소수민족과 홍콩의 문화적 차이 또한 매우 커서 모든 교사와 아동은 ‘학습’과 ‘교수’ 두 측면에서 모두 여러 가지 차이로 인해 발생하는 문제들을 처리해야 했다. 이처럼 비중국어권 학습자들이 홍콩에서 중국어를 배우는 것은 매우 쉽지 않았다. 상술한 문제들을 해결하기 위해서 경마회 자선기금 및 다섯 단체의 공영교육 사회복지기구는 「경마회의 재밌는 중국어 배우기(賽馬會(有)友趣學中文)」 라는 프로젝트를 추진하여, 중국어를 모국어로 갖지 않는 학습자들이 효과적으로 중국어 학습 하여 빠르게 사회에 융화되도록 도왔다. 본 프로 젝트는 수준별 교육과정, 수준별 교재, 수준별 학습법, 수준별 교구, 수준별 평가와 다층적 교학법을 설계하고 지원하여 학습 차이에서 생기는 어려움을 해결하는 데 도움을 주었다. 본고에서는 연구 이론과 설계, 데이터 수집 및 연구 결과를 상세히 서술하고, 효과적인 사례에 대해 상세하게 서술하려고 한다. 이러한 연구 성과는 세계 각지에 광범위하게 적용될 수 있을 것이다. The majority of non-Chinese speaking (NCS) young students are studying in mainstream kindergartens. They are of ethnic groups, for instance, Pakistani, Indian, and Nepalese, who are new immigrants or offspring of immigrants in the past. The Equal Opportunities Commission encourages NCS students to study together with Chinese speaking students, for the sake of social inclusion in the long run. In recent years, the Education Bureau has allocated more resources in supporting NCS students for early adaption to the local education system. However, its effect is not predominant. It is believed that managing individual learning differences is one of the major challenges. NCS students is generally lagging behind those with Chinese as their mother tongue in the Chinese proficiency. Therefore, problems and complications arise as the result of the two groups of students studying in the same environment. Dissimilarities exist even among NCS students, some are new immigrants while some are born in Hong Kong. While there are obvious cultural differences between ethnic minorities and local Hong Kong students, teachers face challenges in handling these disparities. NCS students learning Chinese in Hong Kong is not an easy task. Regarding all these above, The Hong Kong Jockey Club Charities Trust in collaboration with three universities and two social welfare organizations have initiated the “C-for-Chinese@JC” project. It supported NCS students learning Chinese, as well as facilitated early social inclusion. The project developed differentiated school-based curriculum, differentiated teaching and learning materials, differentiated pedagogies and assessment, and varied support measures to kindergartens. Language development of non-Chinese speaking kindergarteners was tracked longitudinally in each of their pre-school years that composed of four language assessments. Significant improvement of language learning results was observed during the three years, which proved the effects of differentiate teaching and learning system. The system is able to alleviate the learning difficulties of NCS preschoolers and bridge the learning differences. This paper detailed research theories and design, data collection, research findings, and analysis of successful cases. The findings of this research could be applied in different settings internationally and be globally referenced.

Derepression of <i>CLDN3</i> and <i>CLDN4</i> during ovarian tumorigenesis is associated with loss of repressive histone modifications

Kwon, Mi Jeong,Kim, Sung-Su,Choi, Yoon-La,Jung, Hun Soon,Balch, Curt,Kim, Su-Hyeong,Song, Yong-Sang,Marquez, Victor E.,Nephew, Kenneth P.,Shin, Young Kee Oxford University Press 2010 Carcinogenesis Vol.31 No.6

<P>Unlike epigenetic silencing of tumor suppressor genes, the role of epigenetic derepression of cancer-promoting genes or oncogenes in carcinogenesis remains less well understood. The tight junction proteins claudin-3 and claudin-4 are frequently overexpressed in ovarian cancer and their overexpression was previously reported to promote the migration and invasion of ovarian epithelial cells. Here, we show that the expression of claudin-3 and claudin-4 is repressed in ovarian epithelial cells in association with promoter ‘bivalent’ histone modifications, containing both the activating trimethylated histone H3 lysine 4 (H3K4me3) mark and the repressive mark of trimethylated histone H3 lysine 27 (H3K27me3). During ovarian tumorigenesis, derepression of <I>CLDN3</I> and <I>CLDN4</I> expression correlates with loss of H3K27me3 in addition to trimethylated histone H4 lysine 20 (H4K20me3), another repressive histone modification. Although <I>CLDN4</I> repression was accompanied by both DNA hypermethylation and repressive histone modifications, DNA methylation was not required for <I>CLDN3</I> repression in immortalized ovarian epithelial cells. Moreover, activation of both <I>CLDN3</I> and <I>CLDN4</I> in ovarian cancer cells was associated with simultaneous changes in multiple histone modifications, whereas H3K27me3 loss alone was insufficient for their derepression. <I>CLDN4</I> repression was robustly reversed by combined treatment targeting both DNA demethylation and histone acetylation. Our study strongly suggests that in addition to the well-known chromatin-associated silencing of tumor suppressor genes, epigenetic derepression by the conversely related loss of repressive chromatin modifications also contributes to ovarian tumorigenesis via activation of cancer-promoting genes or candidate oncogenes.</P>

Intradiscal injection of simvastatin retards progression of intervertebral disc degeneration induced by stab injury

Zhang, Huina,Wang, Lin,Park, Jun Beom,Park, Paul,Yang, Victor C,Hollister, Scott J,La Marca, Frank,Lin, Chia-Ying BioMed Central 2009 Arthritis research & therapy Vol.11 No.6

<P><B>Introduction</B></P><P>Earlier work indicates that the cholesterol-lowering drug, simvastatin, is anabolic to chondrogenic expression of rat intervertebral disc (IVD) cells, which suggests a potential role for simvastatin in IVD regeneration. In this study, we expand on our earlier work to test the effectiveness of simvastatin on disc degeneration utilizing a rat tail disc degeneration model.</P><P><B>Methods</B></P><P>30 rats that underwent 21 G needle-puncture at rat tail discs were injected with simvastatin-loaded poly(ethylene glycol)-poly(lactic acid-co-glycolic acid)-poly(ethylene glycol) (PEG-PLGA-PEG) gel (5 mg/ml) or vehicle control at 4 weeks after needle injury. All animals were sacrificed 2 weeks after simvastatin injection. Bone morphogenetic protein-2 (BMP-2), aggrecan, collagen type II, and collagen type I messenger ribonucleic acid (mRNA) expression in the rat nucleus pulposus (NP) were measured by real-time polymerase chain reaction (PCR). <I>In vivo </I>magnetic resonance imaging (MRI) was performed to monitor changes in disc degeneration. Rat discs were also assessed by histology using hematoxylin and eosin (H&E) and safranin O staining. In addition, the NP weight, glycosaminoglycan (sGAG) and DNA content were also measured.</P><P><B>Results</B></P><P>A single dose of simvastatin loaded in thermo-sensitive PEG-PLGA-PEG gel injected into the NP had the trend to increase aggrecan expression and sGAG content, and significantly increased mRNA levels of BMP-2, collagen type II, and the differentiation index (the ratio of collagen type II to collagen type I). The decreased NP weight, T2 intensity, as well as MRI index in the rat tail discs induced by needle puncture were significantly reversed after 2 weeks of simvastatin treatment. In addition, simvastatin treatment also improved histological changes induced by needle puncture.</P><P><B>Conclusions</B></P><P>A single injection of simvastatin loaded in PEG-PLGA-PEG gel into rat tail discs had the potential to retard or regenerate the degenerative disc.</P>