• Reproductive and Developmental Biology
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• v.32 no.3
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• pp.159-166
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• 2008

We report here the generation of transgenic chickens that produce human Thrombopoietin (hTPO) using replication-defective Moloney murine leukemia virus (MoMLV)-based vectors packaged with vesicular stomatitis virus G glycoprotein (VSV-G). For the retrovirus vectors, we used hCMV (human Cytomegalovirus) internal promoter to drive the hTPO gene. After confirming the expression of the hTPO gene in various target cells, the concentrated solution of recombinant retrovirus was injected beneath the blastoderm of non-incubated chicken embryos (stage X). The biological activity of the recombinant hTPO in target cell was significantly higher than its commercially available counterpart. Out of 132 injected eggs, 11 chicks hatched after 21 days of incubation and 4 hatched chicks were found to express vector-encoded hTPO gene. However, 3 out of the 4 transgenics died within one month of hatching. The major significance of this study is that it is one of the very few successful reports on the production of transgenic chickens as bioreactors aiming mass production of commercially valuable and biological active human cytokine proteins.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.2
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• pp.233-239
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• 1999

Acrodermatitis enteropethica (AE) is a rare autosomal recessive disorder of zinc absorption leading to chronic diarrhea and characteristic skin lesion. The term is also applied to any acquired zinc deficiency state resulting in the same clinical pictures. We experienced one case of AE in 1 month old male infant who had bacterial enterocolitis. The skin around mouth, anus, eyes, ears, hands and legs became reddish, vesicular and eczematoid. Serum zinc level was decreased to $51.4\;{\mu}g/dL$ (N=70~150). Endoscopic finding revealed pale gastric mucosa and villous atrophy of small intestine. Biopsy finding of small intestine showed no villi due to mucosal atrophy. On 13 day of admission jaundice with DIC were noted and AST & ALT were elevated to 110 & 36.8 IU/L, respectively. Diarrhea was improved but jaundice and liver function were not recovered until discharge from hospital. After discharge when the patient was 4 months of age serum bilirubin and AST/ALT had not been normalized. CMV shell vial culture of urine and CMV Ig G antibody were positive. So intravenous ganciclovir injection of 7.5 mg/kg, two times a day for 2 weeks and then 10 mg/kg/day for 3 months was done from 4 to 6 months of age. No virus was found in the urine and AST & ALT were normalized at 2 months after stopping ganciclovir treatment.

• Korean Journal of Veterinary Research
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• v.25 no.1
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• pp.7-17
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• 1985

Many investigators have been pursuing various attempts so far to produce hepatitis B surface antigen(HBsAg) vaccines using the techniques such as isolation from plasma of chronic HBsAg carrier, recombinant DNA technique or preparation of synthetic peptides specific for immunogenic determinants. Hepatitis B virus can not grow on any cell lines by the tissue culture technique at the present time. The plasma of chronic HBsAg carrier is expensive and its source is limited. The HBsAg from the recombinant DNA technique gave still very low yield. Another approach, therefore, has been initiated to develop a synthetic hepatitis B virus vaccine. The possible use of several distinct synthetic vaccines in prophylaxis can be facilitated by availability of full synthetic immunogens. Peptides synthesized for potential application as antiviral vaccines have been mostly tested in the form of conjugates with carrier proteins, although the free synthetic peptide can be immunogenic. To understand basic knowledges on the antigenicity and immunogenicity of a synthetic peptide specific for major immunogenic determinant of HBsAg, a nonapeptide, $H_2N^{139}Cys-Thr-Lys-Pro-Thr-Asp-Gly-^{146}Asn-Aba$ COOH, which corresponds to HBsAg amino acid residues 139 to 147, was synthesized by the Merrifield's solid-phase method with a slight modification. The antigenicity and immunogenicity of this specific synthetic peptide were examined comparing with purified plasma-derived natural HBsAg. The results obtained are as follows; 1. The peptide synthesized showed the identical amino acid composition to the theoretical value. The degree of purification and molecular weight were acertained by methods of high performance liquid chromatography and mass spectrometry. 2. Using m-maleimidobenzoyl-N-hydroxysuccinimide ester as a conjugating agent, the synthetic peptide was conjugated to rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin. Their conjugation yields were 8.3, 9.5, 15.8, 13.5, and 11.2%, respectively. 3. The natural HBsAg was purified from plasma of chronic HBsAg carrier. By the electron microscopic observation of the purified natural HBsAg preparation, no Dane particles were observed and the preparation showed negative DNA polymerase activity. 4. Antigenicity of the synthetic peptide and the plasma-derived natural HBsAg was determined by competition radioimmunoassay using $^{125}I$-natural HBsAg. Their 50% inhibitions appeared as $90{\mu}g/ml$ and $0.12{\mu}g/ml$ for the synthetic peptide and the natural HBsAg, respectively. This indicates that the former was about 750-fold less antigenic than the latter. 5. Immunogenicity of the synthetic peptide was determined by administering the peptide-carrier conjugates into rabbits with and without Freund's complete adjuvant. Regardless the carrier proteins and adjuvant, positive immune responses to the synthetic peptide were observed. The higher antibody titers, however, were shown in the groups administered with Freund's complete adjuvant. 6. Immunizing dose 50% in mice of the various peptide-carrier conjugates was 5.47, 6.00, 65.16, 31.25 and $13.03{\mu}g/dose$ for rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin, respectively, while the natural HBsAg showed $0.65{\mu}g/dose$. 7. It was postulated that homologous proteins prefer to heterologous ones as the carriers.

• Journal of Life Science
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• v.12 no.1
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• pp.49-54
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• 2002

Development of a rapid method possessing the requisite sensitivity and specificity for virus monitoring is necessary for protection of the shellfish-consuming public. Oysters tissue usually contains virus particles in relatively small concentrations along with various other substances that can interfere with detection steps. Therefore, the critical point concerning the detection of viruses in shellfish tissues resides in the processing of samples. The current study demonstrated the possibility of purifying small amounts of virus particles at the interface of a 10/50% sucrose gradient after a single round of sucrose gradient ultracentrifugation. We could detect HAV and poliovirus simultaneously from oyster tissues by using two different sets of primer. Furthermore, the method showed a high level of virus recovery rate (>95%) as determined by plaque assays of the final samples. Taken the advantages of the simple and sensitive methods, it was possible to detect 2 pfu of HAV in 5 g of oyster digestive tissues within 24h.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.350-354
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• 2008

In order to investigate the prevalence of sexually transmitted viruses such as human papillomavirus (HPV) and herpes simplex virus (HSV) in Korean commercial sex workers (CSWs), we selected 188 CSWs (age range 20-44 years, median age 24 years) who regularly visited one public health center in Seoul, Korea. HPV genotypes were analyzed by using a HPV DNA Chip, and an enzyme-linked immunosorbent assay (ELISA) was used to detect type-specific IgG against HSV2 antibody identifying seropositivity for HSV2 infection. Polymerase chain reaction (PCR) was performed with specific primers to detect HPV and HSV1/2 in cervical swabs from the CSWs. The prevalence of HPV infection was 83.5% in 188 cervical swab specimens and the main high-risk HPV genotypes were HPV16, 18, 56, and 58. The principal low-risk HPV genotypes were HPV6 and 11. The prevalence of HSV1/2 DNA was 13.8% and HSV2 seroprevalence was 86.2%. These results suggest that high frequencies of HPV and HSV2 infection might contribute to the rapid spread of STD viruses in CSWs in Korea. Additionally, an understanding of why high-risk HPV genotypes are so prevalent could provide guidelines for prophylactic vaccine development in Korea.

• IMMUNE NETWORK
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• v.2 no.1
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• pp.41-48
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• 2002

Background: Viral antigens presented on the cell surface in association with MHC class I molecules are recognized by CD8+ T cells. MHC restricted peptides are important in eliciting cellular immune responses. As peptide antigens have a weak immunigenicity, pH-sensitive liposomes were used for peptide delivery to induce effective cytotoxic T lymphocyte (CTL) responses. In the previous study, as the HBx peptides could induce specific CTLs in vitro, we tested whether the HLA-A2/$K^b$ transgenic mice that were immunized by HBx-derived peptides could be protected from a viral challenge. Methods: HBx-peptides encapsulated by pH-sensitive liposomes were prepared. $A2K^b$ transgenic mice were immunized i.m. on days one and seven with the indicated concentrations of liposome-encapsulated peptides. Three weeks later, mice were infected with $1{\times}10^7pfu$/head of recombinant vaccinia virus (rVV)-HBx via i.p. administration. The ovaries were extracted from the mice, and the presence of rVV-HBx in the ovaries was analyzed using human TK-143B cells. IFN-${\gamma}$ secretion by these cells was directly assessed using a peptide-pulsed target cell stimulation assay with either peptide-pulsed antigen presenting cells (APCs), concanavalin A ($2{\mu}g/ml$), or a vehicle. To generate peptide-specific CTLs, splenocytes obtained from the immunized mice were stimulated with $20{\mu}g/ml$ of each peptide and restimulated with peptide-pulsed APC four times. The cytotoxic activity of the CTLs was assessed by standard $^{51}Cr$-release assay and intracellular IFN-${\gamma}$ assay. Results: Immunization of these peptides as a mixture in pH-sensitive liposomes to transgenic mice induced a good protective effect from a viral challenge by inducing the peptide-specific CD8+ T cells. Mice immunized with $50{\mu}g/head$ were much better protected against viral challenge compared to those immunized with $5{\mu}g$/head, whereas the mice immunized with empty liposomes were not protected at all. After in vitro CTL culture by peptide stimulation, however, specific cytotoxicity was much higher in the CTLs from mice immunized with $5{\mu}g/head$ than $50{\mu}g/head$ group. Increase of the number of cells that intracellular IFN-${\gamma}$ secreting cell among CD8+ T cells showed similar result. Conclusion: Mice immunized with XEPs within pH-sensitive liposome were protected against viral challenge. The protective effect depended on the amount of antigen used during immunization. XEP-3-specific CTLs could be induced by peptide stimulation in vitro from splenocytes obtained from immunized mice. The cytotoxic effect of CTLs was measured by $^{51}Cr$-release assay and the percentage of accumulated intracellular IFN-${\gamma}$ secreting cells after in vitro restimulation was measured by flow cytometric analysis. The result of $^{51}Cr$-release cytotoxicity test was well correlated with that of the flow cytometric analysis. Viral protection was effective in immunized group of $50{\mu}g/head$, while in the in vitro restimulation, it showed more spectific response in $5{\mu}g$/head group.

• Molecules and Cells
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• v.40 no.3
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• pp.202-210
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• 2017

The nonstructural protein 5A (NS5A) encoded by the human hepatitis C virus (HCV) RNA genome is a multifunctional phosphoprotein. To analyse the influence of NS5A on apoptosis, we established an Hep-NS5A cell line (HepG2 cells that stably express NS5A) and induced apoptosis using tumour necrosis factor $(TNF)-{\alpha}$. We utilised the MTT assay to detect cell viability, real-time quantitative polymerase chain reaction and Western blot to analyse gene and protein expression, and a luciferase reporter gene experiment to investigate the targeted regulatory relationship. Chromatin immunoprecipitation was used to identify the combination of $NF-{\kappa}B$ and miR-503. We found that overexpression of NS5A inhibited $TNF-{\alpha}$-induced hepatocellular apoptosis via regulating miR-503 expression. The cell viability of the $TNF-{\alpha}$ induced Hep-mock cells was significantly less than the viability of the $TNF-{\alpha}$ induced Hep-NS5A cells, which demonstrates that NS5A inhibited $TNF-{\alpha}$-induced HepG2 cell apoptosis. Under $TNF-{\alpha}$ treatment, miR-503 expression was decreased and cell viability and B-cell lymphoma 2 (bcl-2) expression were increased in the Hep-NS5A cells. Moreover, the luciferase reporter gene experiment verified that bcl-2 was a direct target of miR-503, NS5A inhibited $TNF{\alpha}$-induced $NF-{\kappa}B$ activation and $NF-{\kappa}B$ regulated miR-503 transcription by combining with the miR-503 promoter. After the Hep-NS5A cells were transfected with miR-503 mimics, the data indicated that the mimics could reverse $TNF-{\alpha}$-induced cell apoptosis and blc-2 expression. Collectively, our findings suggest a possible molecular mechanism that may contribute to HCV treatment in which NS5A inhibits $NF-{\kappa}B$ activation to decrease miR-503 expression and increase bcl-2 expression, which leads to a decrease in hepatocellular apoptosis.

• Journal of Microbiology
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• v.37 no.2
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• pp.86-89
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• 1999

An OTHBVS cell line from HepG2 was established. This cell line stably expresses the human hepatitis B virus (HBV) middle S protein that includes the preS2 region which is important for HBV particle entry into the hepatocyte. To establish this cell line, the middle S open reading frame (ORF), with a promoter located in the 5' region and enhancer located in the 3' region, was cloned downstream from the metallothionine (MT) promoter of the OT1529 vector. In this vector, expression of the middle S protein was constructed to be regulated by its own promoter and enhancer. Expression of the large S protein which contains the preS1 region in addition to the middle S protein was designed to be regulated by the MT promoter. When extracts of OTHBVS cells were examined with an S protein detection kit (RPHA, Korea Green Cross Co.), an S protein was detected. Total mRNA of OTHBVS cell examined by northern blot analysis with an S ORF probe revealed small/middle S transcripts (2.1 kb). When the MT promoter was induced by Zn, large S transcripts (2.4 kb) were detected. The GP36 and GP33 middle S proteins were presumably detected, but large S proteins were not detected by immunostain analysis using anti-preS2 antibody.

• KSBB Journal
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• v.26 no.2
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• pp.157-164
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• 2011

Five assays for anti-HBs were compared to improve potency test of Human lgG preparations. The three commercial EIA kits were optimized including dose response curve ranges and compared by conducting a co-laboratory study. After selecting the most reproducible EIA kit, methods comparison was performed with 22 samples in 5 different days. As a result, EIA (7.7 ${\pm}$ 5.3%) and MEIA (AxSYM: 3.7 ${\pm}$ 1.9%, IMx: 1.6 ${\pm}$ 0.8%) showed precision and accuracy (100.1 ${\pm}$ 12.6%). Therefore, the validated EIA assay was established and it is believed to be comparable to current MEIA.

• Journal of Yeungnam Medical Science
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• v.24 no.2
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• pp.170-178
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• 2007

Background : The incidence of acute hepatitis A in adults has recently been increasing. This study was conducted to investigate the epidemiology and clinical characteristics of acute hepatitis A in Daegu province over the past 10 years. Materials and Methods : We reviewed the medical records of 55 patients (male/female: 34/21), who were diagnosed with acute hepatitis A by confirmation of the IgM anti-HAV between January 1998 and June 2007. Results : The mean age was $29.7{\pm}10.3$ years (range; 17-65 years). The incidence was most common between March and June (56.1%), in the third and fourth decades of life (78.2%) and 90.9% (50/55) of the patients were diagnosed from 2003 to present. The common symptoms included anorexia, nausea or vomiting (69.1%), fever and chills (49.1%), myalgia (47.3%), weight loss (47.3%), fatigue (40.0%), abdominal pain (36.4%), diarrhea (9.1%) and pruritus (5.5%). The mean duration of hospital stay was $8.6{\pm}3.4$ days (range; 3-20 days). The route of transmission was identified in only 11 patients (20.0%); 7 patients (12.7%) traveled (abroad or domestic), 2 patients (3.6%) ingested raw food and 2 patients (3.6%) had friends with acute hepatitis A. Fifty four patients recovered without complication; one patient developed fulminant hepatitis and recovered after a liver transplantation. Conclusion : The incidence of acute hepatitis A in adults is increasing. Because of the cost of treatment and potential for serious disease, persons, under 40 are recommened to have hepatitis A vaccination and confirmation of IgG anti-HAV.