• Asian-Australasian Journal of Animal Sciences
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• 제16권2호
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• pp.227-233
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• 2003

Two experiments were conducted to evaluate the effects of chromium (Cr) on the growth performance, bone trait, serum traits, and immune responses in broilers. The broilers were fed corn-soybean meal basal diet supplemented with Cr at level of 0(control), 200, 400, or 800 ppb in the form of chromium picolinate (CrPic). The broilers were fed treated diets for 6 weeks in Exp. 1, but the Cr supplement was removed for the last 3 weeks in Exp. 2. Exp. 1 showed that dietary supplement of Cr did not affect growth performance of the broiler, though improved feed efficiency (p<0.05) was observed during 0 to 3 weeks. Moreover, serum total (p<0.05) and HDL cholesterols (p<0.06) were significantly higher in pooled Cr added group at 6 weeks of age, however, the difference was not significant in Exp. 2. The pooled Cr added group in Exp.1 had significantly lower (p<0.05) alkaline phosphatase activity and higher (p<0.09) calcium at 3 weeks. Significantly lower phosphorus was also observed in Exp. 2. With continued supplement of Cr as in Exp. 1, the alkaline phosphatase activity maintained higher at 6 weeks, as opposed to significantly lower in Exp. 2, which had no further Cr supplement. Higher bone breaking strength was observed in 400 ppb Cr supplemented in Exp. 1, though not significantly different. Serum glucose and triglyceride were not affected by Cr supplement. Antibody against Infectious Bronchitis (IB) was significantly (p<0.05) higher with 400 ppb Cr supplemented, and anti-Newcastle disease (ND) antibody also tended to be higher (p<0.06) in pooled Cr added group at 6 weeks of age in Exp. 1. Peripheral blood blastogenesis activity was not different among the treatments. The results suggest that diet supplemented with 400 ppb CrPic may be beneficial to the broiler.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.362-366
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• 2005

Actinobacillus pleuropneumoniae is an important pig pathogen, which is responsible for swine pleuropneumonia, a highly contagious respiratory infection. To develop subunit vaccines for A. pleuropneumoniae infection, the Apx toxin genes, apxI and apxII, which are thought to be important for protective immunity, were expressed in Saccharomyces cerevisiae, and the induction of immune responses in mice was examined. The apxI and apxII genes were placed under the control of a yeast hybrid ADH2-GPD promoter (AG), consisting of alcohol dehydrogenase II (ADH2) and the GPD promoter. Western blot analysis confirmed that both toxins were successfully expressed in the yeast. The ApxIA and ApxIIA-specific IgG antibody response assays showed dose dependent increases in the antigen-specific IgG antibody titers. The challenge test revealed that ninety percent of the mice immunized with ApxIIA or a mixture of ApxIA and ApxIIA, and sixty percent of mice immunized with ApxIA survived, while none of those in the control groups survived longer than 36 h. These results suggest that vaccination of the yeast ex­pressing the ApxI and ApxII antigens is effective for the induction of protective immune responses against A. pleuropneumoniae infections in mice.

• IMMUNE NETWORK
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• 제2권4호
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• pp.233-241
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• 2002

Background: Monoclonal antibodies (mAb) of rodent origin are produced with ease by hybridoma fusion technique, and have been successfully used as therapeutic reagents for humans after humanization by genetic engineering. However, utilization of these antibodies for therapeutic purpose has been limited by the fact that they act as immunogens in human body causing undesired side effects. So far, there have been several attempts to produce human mAbs for effective in vivo diagnostic or therapeutic reagents including the use of humanized xenomouse that is generated by mating knockout mice which lost Ig heavy and light chain genes by homologous recombination and transgenic mice having both human Ig heavy and light gene loci in their genome. Methods: Genomic DNA fragments of mouse Ig heavy and light chain were obtained from a mouse brain ${\lambda}$ genomic library by PCR screening and cloned into a targeting vector with ultimate goal of generating Ig knockout mouse. Results: Through PCR screening of the genomic library, three heavy chain and three light chain Ig gene fragments were identified, and restriction map of one of the heavy chain gene fragments was determined. Then heavy chain Ig gene fragments were subcloned into a targeting vector. The resulting construct was introduced into embryonic stem cells. Antibiotic selection of transfected cells is under the progress. Conclusion: Generation of xenomouse is particularly important in medical biotechnology. However, this goal is not easily achieved due to the technical difficulties as well as huge financial expenses. Although we are in the early stage of a long-term project, our results, at least, partially contribute the successful generation of humanized xenomouse in Korea.

• Asian-Australasian Journal of Animal Sciences
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• 제22권4호
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• pp.591-597
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• 2009

Egg white protein (EWP) was glycated with maltopentaose (MP) through the Maillard reaction and subsequently phosphorylated by $85^{\circ}C$ dry-heating at pH 4.0 for 1 d in the presence of pyrophosphate. The functional properties of glycated, phosphorylated EWP were compared with those of native EWP and with EWP which was phosphorylated by dry-heating in the presence of pyrophosphate under the same conditions. The phosphorus content of EWP was increased to ~0.60% by phosphorylation, and to ~0.74% by glycation with MP and subsequent phosphorylation. The electrophoretic mobility of EWP increased through phosphorylation. The stability of EWP against heat-induced insolubility at pH 7.0 was considerably improved by phosphorylation alone and further by phosphorylation after glycation. The anti-ovalbumin antibody response was reduced significantly by glycation and phosphorylation, and further reduced by phosphorylation after glycation. The anti-ovomucoid antibody response was reduced significantly by glycation, phosphorylation and phosphorylation after glycation. The calcium phosphate-solubilizing ability of EWP was enhanced by both phosphorylation methods.

• Journal of Biosystems Engineering
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• 제38권4호
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• pp.335-340
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• 2013

Purpose: This study was performed to develop a lateral flow strip sensor for the detection of pathogenic Escherichia coli O157:H7 in various samples. Also, feasibility of using an image analysis method to improve the interpretation of the strip sensor was evaluated. Methods: The lateral flow strip sensor has been fabricated based on nitrocellulose lateral-flow membrane. Colloidal gold and E. coli O157:H7 antibodies were used as a tag and a receptor, respectively. Manually spotted E. coli O157:H7 antibody and anti-mouse antibody on nitrocellulose membrane were used as test and control dots, respectively. Feasibility of the lateral flow strip sensor to detect E. coli O157:H7 were evaluated with serially diluted E. coli O157:H7 cells in PBS or food samples. Test results of the lateral flow strip sensor were measured with an image analysis method. Results: The intensity of the test dot started to increase with higher concentration of the cells were introduced. The sensitivities of the sensor were both $10^4$ CFU/mL Escherichia coli O157:H7 spiked in PBS and in chicken meat extract, respectively. Conclusions: The lateral flow strip sensor and image analysis method could detect E. coli O157:H7 in 20 min, which is significantly quicker than conventional plate counting method.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.528-532
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• 2019

본 연구는 뉴런 세포와 슈반 세포의 공동 배양에 의한 수초화 발생 과정과 herpes simplex virus-1 감염에 의한 탈수초화 발생과정을 전자 현미경과 분자생물학적 분석에 의하여 확인하고자 하였다. 쥐의 배아로부터 후근신경절(dorsal root ganglion, DRG)을 분리하여 슈반(Schwann) 세포와 뉴런 세포(neuronal cell)를 in vitro에서 각각 배양하였다. 유사 분열 억제인자로 처리한 뉴런세포와 정제된 슈반 세포를 함께 공동 배양을 하여 수초화를 발생시켰다. 이렇게 수초화된 공동 배양 세포에 herpes simplex virus-1를 감염시켜 탈수초화를 진행시켰다. 수초 형성의 존재를 의미하는 myelin protein zero(MPZ) 항체를 사용하고 전자 현미경을 이용하여 수초 발생 및 탈수초화 과정을 관찰하였다. 이 연구는 과학 기술부, ICT 및 미래 계획 (NRF-2016R1A2B4016552 및 2017R1A2B3005753)이 자금을 지원하는 국립 연구 재단 (NRF)을 통한 기초 연구 프로그램의 지원을 받았다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.82-86
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• 1998

The maltose binding protein (MBP) fusion protein system is a versatile tool to express and isolate recombinant proteins in E. coli. In this system, MBP fusion proteins are efficiently isolated from whole cell lysate using amylose conjugated agarose beads and then eluted by competition with free maltose. Since MBP is a rather large molecule (∼42 kDa), for further experiments, the MBP part is usually proteolytically cleaved from the fusion protein and subsequently removed by ion-exchange chromatography or rebinding to amylose columns after washing out excess and MBP-bound maltose. In the present study, we have developed an improved method for the removal of cleaved MBP, which is advantageous over conventional methods. In this method, factor Xa cleaved MBP fusion proteins were incubated with Sepharose beads conjugated with MBP specific monoclonal antibodies and then precipitated buy centrifugation, resulting in highly purified proteins in the supernatant.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.97-99
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• 1996

Intracellular gradients of the free calcium concentration are thought to be critical for the localization of functional responses within a cell. The mechanism of mechanotransduction may be associated with the localized accumulation of calcium stores for shear stress-exposed endothelial cells. The distribution of the calcium stores and the formation of the stress fibers were investigated by the indirect double immunofluorescent staining method with the calreticulin antibody and rhodamine phalloidin under flow condition. The shear stress of steady flow reorganized the cytoskeleton structure including the bundling and translocation to focal contacts. The calcium stores translocated from the cytoplasm to the focal contacting area. Consequently. accumulation of the calcium stores may participate in the shear stress-induced cytoskeleton organization of endothelial cells.

• BMB Reports
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• 제38권5호
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• pp.517-525
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• 2005

Solid phase peptide synthesis method, which was introduced by Merrifield in 1963, has spawned the concept of combinatorial chemistry. In this review, we summarize the present technologies of solid phase peptide synthesis (SPPS) that are related to combinatorial chemistry. The conventional methods of peptide library synthesis on polymer support are parallel synthesis, split and mix synthesis and reagent mixture synthesis. Combining surface chemistry with the recent technology of microelectronic semiconductor fabrication system, the peptide microarray synthesis methods on a planar solid support are developed, which leads to spatially addressable peptide library. There are two kinds of peptide microarray synthesis methodologies: pre-synthesized peptide immobilization onto a glass or membrane substrate and in situ peptide synthesis by a photolithography or the SPOT method. This review also discusses the application of peptide libraries for high-throughput bioassays, for example, peptide ligand screening for antibody or cell signaling, enzyme substrate and inhibitor screening as well as other applications.

• Journal of Biosystems Engineering
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• 제35권2호
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• pp.116-123
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• 2010

Rapid detection of foodborne pathogens has been a major challenge for the food industry. Salmonella contamination is well known in all foods including pasteurised milk. The possibility of specific detection of Salmonella Enteritidis by surface plasmon resonance (SPR) biosensor was explored using a commercially available portable SPR sensor. Self assembly technique was adopted to immobilize anti-Salmonella antibodies on the gold sensing surface of the SPR sensor. The concentration of polyclonal antibody for use in the SPR biosensor was chosen to 1.0 mg/mL. Experiments were conducted at near real-time with results obtained for one SPR biosensor assay within 1 hour. The limit of detection for Salmonella Enteritidis was determined to be $10^6$ CFU/mL in both PBS buffer and milk samples. The assay sensitivity was not significantly affected by milk matrix. Our results showed that it would be possible for employing the SPR biosensor to detect Salmonella Enteritidis in near real-time.