• Journal of Microbiology
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• v.44 no.3
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• pp.293-300
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• 2006

The Escherichia coli heat-labile enterotoxin B subunit (HLT-B) is one of the most powerful mucosal immunogens and known mucosal adjuvants. However, the induction of high levels of HLT-B expression in E. coli has proven a difficult proposition. Therefore, in this study, the HLT-B gene was cloned from pathogenic E. coli and expressed as a fusion protein with GST (glutathion S-transferase) in E. coli BL2l (DE3), in an attempt to harvest a large quantity of soluble HLT-B. The culture conditions, including the culture media used, temperature, pH and the presence of lactose as an inducer, were all optimized in order to obtain an increase in the expression of soluble GST-rHLT-B. The biological activity of the purified rHLT-B was assayed in a series of GMI-ELISA experiments. The findings of these trials indicated that the yield of soluble recombinant GST-rHLT-B could be increased by up to 3-fold, as compared with that seen prior to the optimization, and that lactose was a more efficient alternative inducer than IPTG. The production of rHLT-B, at 92 % purity, reached an optimal level of 96 mg/l in a 3.7 L fermentor. The specific GM1 binding ability of the purified rHLT-B was determined to be almost identical to that of standard CTB.

• Microbiology and Biotechnology Letters
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• v.40 no.1
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• pp.10-16
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• 2012

The Streptomyces peucetius OIM (Overproducing Industrial Mutant) strain is a recursively-mutated and optimally-screened strain used for the industrial production of polyketide antibiotics, such as doxorubicin (DXR). Using the S. peucetius OIM mutant strain as a surrogate host, a model minimal polyketide pathway for aloesaponarin II, an actinorhodin shunt product, was cloned in a high-copy conjugative plasmid, followed by functional pathway expression and quantitative metabolite analysis. The level of aloesaponarin II production was noted as being significantly higher in the OIM strain than in the wild-type S. peucetius, as well as in the regulatory network-stimulated S. coelicolor mutant strain. Moreover, the aloesaponarin II production level was seen to be even higher in a down-regulator $wblA_{spe}$-deleted S. peucetius OIM strain, implying that the rationally-engineered S. peucetius OIM mutant strain could be used as an efficient surrogate host for the high expression of foreign polyketide pathways.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3451-3455
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• 2014

Background: The serum carcinoembryonic antigen (CEA) level can reflect tumor growth, recurrence and metastasis. It has been reported that epidermal growth factor receptor (EGFR) mutations in exons 19 and 21may have an important relationship with tumor cell sensitivity to EGFR-TKI therapy. In this study, we investigated the clinical value of EGFR mutations and serum CEA in patients with non-small cell lung cancer (NSCLC). Materials and Methods: The presence of mutations in EGFR exons 19 and 21 in the tissue samples of 315 patients with NSCLC was detected with real-time fluorescent PCR technology, while the serum CEA level in cases who had not yet undergone surgery, radiotherapy, chemotherapy and targeted therapy were assessed by electrochemical luminescence. Results: The mutation rates in EGFR exons 19 and 21 were 23.2% and 14.9%, respectively, with the two combined in 3.81%. Measured prior to the start of surgery, radiotherapy, chemotherapy and targeted treatment, serum CEA levels were abnormally high in 54.3% of the patients. In those with a serum CEA level <5 ng/mL, the EGFR mutation rate was 18.8%, while with 5~19 ng/mL and ${\geq}20ng/mL$, the rates were 36.4% and 62.5%. In addition, in the cohort of patients with the CEA level being 20~49 ng/mL, the EGFR mutation rate was 85.7%, while in those with the CEA level ${\geq}50ng/mL$, the EGFR mutation rate was only 20.0%, approximately the same as in cases with the CEA level<5 ng/mL. Conclusions: There is a positive correlation between serum CEA expression level and EGFR mutation status in NSCLC patients, namely the EGFR mutation-positive rate increases as the serum CEA expression level rises within a certain range (${\geq}20ng/mL$, especially 20~49 ng/mL). If patient samples are not suitable for EGFR mutation testing, or cannot be obtained at all, testing serum CEA levels might be a simple and easy screening method. Hence, for the NSCLC patients with high serum CEA level (${\geq}20ng/mL$, especially 20~49 ng/mL), it is worthy of attempting EGFR-TKI treatment, which may achieve better clinical efficacy and quality of life.

• Journal of Animal Science and Technology
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• v.57 no.3
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• pp.8.1-8.8
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• 2015

Background: The demand for healthy, lean and consistent meat products containing low saturated fatty acid content and high quality polyunsaturated fatty acids (PUFA), especially long-chain (${\geq}C_{20}$) omega-3 PUFA, has increased in recent times. Fat deposition is altered by both the genetic background and dietary supplements, and this study aimed to assess the effect of dietary Spirulina supplementation levels on the mRNA expression patterns of genes controlling lipid metabolism in the subcutaneous adipose tissue (SAT) and Longissimus dorsi (ld) muscle of Australian crossbred sheep. Methods: Twenty-four weaned lambs belonging to four breeds under the same management conditions were maintained on ryegrass pasture and fed three levels of Spirulina supplement (control, low and high). In terms of nutrient composition, Spirulina is a nutrient-rich supplement that contains all essential amino acids, vitamins and minerals. It also is a rich source of carotenoids and fatty acids, especially gamma-linolenic acid (GLA) that infer health benefits. After slaughter, subcutaneous adipose tissue (SAT) and ld samples were subjected to mRNA extraction and reverse transcription using quantitative polymerase chain reaction (RT-qPCR) to assess the mRNA expression levels of the Aralkylamine N-acetyltransferase (AANAT), Adrenergic beta-3 receptor (ADRB3), B-cell translocation gene 2 (BTG2) and Fatty acid synthase (FASN) genes, which are associated with lipid metabolism. Results: Both low and high Spirulina supplementation levels strongly up-regulated the transcription of all the selected genes in both SAT and ld tissues (mostly in the subcutaneous adipose), but sheep breed and sex did not influence the gene expression patterns in these tissues. Conclusions: The evidence indicates that high Spirulina supplementation level resulted in a decrease in intramuscular fat content in Australian purebred and crossbred sheep due to the enhanced production of melatonin in sheep muscle tissues and strong up-regulation of mRNA expression of BTG2 in SAT which negatively affected fat deposition. In contrast, low Spirulina supplementation level strongly up-regulated the ADRB3 and FASN genes responsible for fat production. These findings are consistent with the observed phenotypic data suggesting that low Spirulina supplementation level can increase lamb production, with higher long-chain PUFA content.

• The Journal of the Korea Contents Association
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• v.19 no.4
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• pp.315-325
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• 2019

Loss experience can bring more negative impact to the person, if experienced in a younger period. This study examined how self-esteem mediates the effect of emotional expression and maladaptive emotion regulation strategies regarding one's loss during adolescence among college students on depression. The data of 380 college students entails what kind of loss was experienced, how the level of self-esteem mediated the effect of emotional expression and maladaptive emotion regulation strategy after loss experience on depression; and it was analyzed with SPSS 21.0 and Amos 21.0. The results showed that emotional expression about loss experiences was negatively correlated with depression (${\beta}=-.180$, p<.01), and maladaptive emotion regulation strategies showed a positive correlation with depression (${\beta}=.266$, p<.001). The emotional expression of loss experiences decreased the level of depression by increasing the level of self - esteem, and maladaptive emotion regulation strategy of loss experience increased depression level by lowering self-esteem level. Therefore, it is conceivable to assume that the more people articulate on various emotional experiences after their loss and think positively about themselves, and the less they criticize for themselves, the less likely they are to experience depression while maintaining high self-esteem.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.437-443
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• 2010

To be economically profitable, the poultry industry demands an increase in stocking density, which could adversely affect chicken welfare. The current study was performed to investigate the effect of stocking density on stress-related, heat shock protein genes (HSP70 and HSP90), 3-hydroxyl-3-methyl-glutaryl coenzyme A reductase (HMGCR) gene and telomere length in broiler chickens. Seven-day-old broiler chickens were housed at High (0.0578 $m^2$/bird), Standard (0.077 $m^2$/bird) and Low (0.116 $m^2$/bird) stocking densities with 8 replicates each until 35 d of age. The growth performance, such as body weight gain and average daily feed intake, was found to be significantly (p<0.05) higher in the Low density group, but these parameters did not show any difference between the High and Standard groups. Other growth performance, such as feed conversion ratio and final feed intake, showed no difference among the treated groups. The expression levels of HSP70 and HMGCR were found to be elevated with the increase of stocking density. The expression level of these genes was significantly (p<0.05) higher in the High density stocked group compared with the other groups, whereas the expression levels were not significantly different between the Low and Standard groups. The expression levels of HSP90 did not show any significant changes among the treated groups. The telomeric length of the birds housed in High density was reduced significantly (p<0.05) when compared to that of the birds in Low density. These results clearly indicate that birds stocked at high density show physiological adaptive changes indicative of stress at gene transcriptional and telomere levels.

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.292-298
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• 2007

Zinc plays indispensable roles in metabolism, including cell growth, apoptosis, proliferation and differentiation. Kidneys are target organs for various regulators of mineral metabolism, and play a key role in zinc balance. To investigate the zinc uptake efficiency, we examined the zinc uptake and accumulation level in vivo and in vitro study. Plasma zinc concentration was peaked out at 1 hr after oral zinc administration. The renal zinc level was peaked out at 12 hr after oral zinc administration, and it was the highest in 40 mg/kg Zn-Asp administrated group in comparison with other groups. In addition, the m-RNA expression level of zinc transporter-1 (ZnT-1), zinc transporter-2 (ZnT-2) and high-affinity L-aspartate transporter (EAAT-3) in Zn-Asp administered group were increased compared with control groups and $ZnSO_4$ group. In order to investigate the intracellular zinc uptake mechanism, we performed the in vitro study by using human embryonic kidney cell line, HEK 293. Intracellular zinc level was peaked out at 3 hr after zinc treatment. In the same way, the mRNA expression level of ZnT-1 and EAAT-3 were increased compared with control group. This study showed that Zn-Asp is effective the zinc uptake into the kidney by increasing the zinc transporter expression.

• The Korean Journal of Zoology
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• v.33 no.4
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• pp.446-453
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• 1990

In order to investigate the retinoic acid indticed-differentiation of F9 teratocarcinoma stem cell, we have analyzed the change of cell morphology and laminin expression after exposure to retinoic add and cyclic AMP. It is shown that undifferentiated F9 stem cells grow as closely packed colonies, and it is difficult to distinguish cell-cell boundaries. After retinoic add and dibutyryl cyclic AMP treatment, F9 cells assume a flat morphology characterized by perinuclear granules and arrest growth. According to Northern blot analysis, laminin expression was increased markedly after retinoic acid treatment. Laminin Bi gene expression was increased at least 30-fold and laminin B2 gene expression was increased approximately 20-fold during differentiation process. Employing immunofluoresence analysis, it was proved that the synthesis of laminin protein was low level in F9 stem cell whereas it became high level in retinoic acid treated F9 cell and the laminin protein was largely accumulated in the cell surface. Our results suggest that induction of laminin Bi and B2 genes m F9 cells is retinoic acid-mediated control, and morphological change and differentiation of F9 cells might be associated with laminin gene expression.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.1
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• pp.20-24
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• 2015

Insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-1 (IGFBP-1) play a pivotal role in regulating cellular hypoxic response. In this study, we cloned and characterized the genes encoding IGF-1 and IGFBP-1 to improve the current knowledge on their roles in highland Bos grunniens (Yak). We also compared their expression levels in the liver and kidney tissues between yaks and lowland cattle. We obtained full-length 465 bp IGF-1 and 792 bp IGFBP-1, encoding 154 amino acids (AA) IGF-1, and 263 AA IGFBP-1 protein, respectively using reverse transcriptase-polyerase chain reaction (RT-PCR) technology. Analysis of their corresponding amino acid sequences showed a high identity between B. grunniens and lowland mammals. Moreover, the two genes were proved to be widely distributed in the examined tissues through expression pattern analysis. Real-time PCR results revealed that IGF-1 expression was higher in the liver and kidney tissues in B. grunniens than in Bos taurus (p<0.05). The IGFBP-1 gene was expressed at a higher level in the liver (p<0.05) of B. taurus than B. grunniens, but it has a similar expression level in the kidneys of the two species. These results indicated that upregulated IGF-1 and downregulated IGFBP-1 are associated with hypoxia adaptive response in B. grunniens.

• Toxicological Research
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• v.16 no.1
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• pp.67-71
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• 2000

It has been demonstrated that the injection of naked DNA expressing vascular endothelial growth factor 165(VEGFl165) to the affected area can provide significant therapeutic effects on peripherol artery occlusive diseases. Success with this type of gene therapy highly depends on the quality of the vector delivering the therapeutic gene, especially in terms of the level and duration of gene expression in the localized area. We have recently developed a vector expressing VEGF165(pCK-VEGF) for the treatment of peripheral artery occulsive diseases and demonstrated high level expression of VEGF165 in mouse skeletal muscle. This study was designed to assess the acute toxicity of intramuscularly injected pCK-VEGF in BALB/c mice and Sprague-Dawely rats. There was no evidence of any changes in clinical signs, body weights, or gross pathological signs. We estimate LD50 values of pCK-VEGF higher than 50mg/kg in mice and 20 mg/kg in rats by intramuscular injection.