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The semiconductor industry is one of the key industries of Korea, which has continued growing at a steady annual growth rate. Important technology for the semiconductor industry is high integration of devices. This is to increase the memory capacity for unit area, of which key is photolithography. The photolithography refers to a technique for printing the shadow of light lit on the mask surface on to wafer, which is the most important process in a semiconductor manufacturing process. In this study, the width and step-height of wafers patterned through this process were measured to ensure uniformity. The widths and inter-plate heights of the specimens patterned using photolithography were measured using transmissive digital holography. A transmissive digital holographic interferometer was configured, and nine arbitrary points were set on the specimens as measured points. The measurement of each point was compared with the measurements performed using a commercial device called scanning electron microscope (SEM) and Alpha Step. Transmission digital holography requires a short measurement time, which is an advantage compared to other techniques. Furthermore, it uses magnification lenses, allowing the flexibility of changing between high and low magnifications. The test results confirmed that transmissive digital holography is a useful technique for measuring patterns printed using photolithography.

In the fabrication of electronic circuits used in electronic products, molybdenum thin films are deposited on semiconductors to prevent oxidation. During the deposition, the presence of a particle or dust at the interface between the thin film and substrate causes the decrease of adhesion, performance, and life cycle. In this study, a damage measurement targeting two kinds of glass substrate, with and without particles, was performed in order to measure the change in the molybdenum thin film deposition area in the presence of a particle. Clean and dirty molybdenum thin film specimens were fabricated and directly deposited on a substrate using the sputtering method, and a reflection-type digital holographic interferometer was configured for measuring the damage. Reflection-type digital holography has several advantages; e.g., the configuration of the interferometer is simple, the measurement range can be varied depending on the magnification of a microscopic lens, and the measuring time is short. The results confirm that reflection-type digital holography is useful for the measurement of the damage and defects of thin films.

The avidity for CD80Ig/CD86Ig and the in vitro immunosuppressive effect of recombinant human cytotoxic T lymphocyte-associated antigen 4-immunoglobulin, produced by transgenic rice cell suspension cultures (hCTLA4Ig(P)) with CHO-derived recombinant hCTLA4Ig (hCTLA4Ig(M)), were measured. Surface plasmon resonance (SPR) was used for kinetic binding analysis: hCTLA4Ig(P) and hCTLA4Ig(M) had higher avidity for CD80Ig/CD86Ig than for CD28Ig, and the avidity for CD80Ig/CD86Ig was similar. hCTLA4Ig(P) and hCTLA4Ig(M) had similar in vitro immunosuppressive activity against the expression of T cell-derived cytokines, such as IL-2, IL-4, and IFN-gamma, but did not suppress the expression of macrophage-derived cytokines, including TNF-alpha and IL-1beta, as well as NO. Thus the immunosuppressive mechanism of hCTLA4Ig(P) is also T cell-specific and it could therefore be used as an immunosuppressive agent with an equivalent potency to that of hCTLA4Ig(M).

A long-lasting recombinant human albumin-linker-erythropoietin (EPO) is a human albumin gene fused to the N-terminal of EPO with a (GGSGG)(n)-repeated linker inserted between albumin and EPO. Albumin-EPO fusion genes were co-transfected with the dhfr gene. Albumin-EPO fusion protein has three kinds of sub-types (IALE, AD2LE, AD1LE). Albumin-EPO fusion protein was quantified with human EPO ELISA. The in vitro efficacy of albumin-EPO fusion protein was estimated using F-36E cell, and in vivo efficacy of albumin-EPO fusion protein was estimated using normocythemic mice (B6D2F1). We also determined the in vivo half-life in a Sprague-Dawley rat. A PLA program analysis result demonstrated that the albumin-EPO fusion protein IALE is about 7.8-fold more potent than rHuEPO in increasing the hematocrit of normal mice.

It is essential to develop an in vitro culture model of primary hepatocytes for the study of hepatocellular function and the pathogenesis of hepatitis C virus (HCV) infection. In this study, we have established the immortalized primary human hepatocyte (IPHH) and performed in vitro culture of HCV derived from human patient.Primary human hepatocytes were isolated from surgically resected liver tissue and then were immortalized by transfection with the SV40 large T antigen. The characterization of the IPHH during culture was analyzed by immunocytochemistry, RT-PCR, Western blot, ELISA, and soft agar assay. Next, sera and/or liver tissue homogenates from surgically resected liver tissues of patients with HCV infection were inoculated for the culture of HCV in IPHH. After HCV RNA extraction from IPHH and culture media, positive or negative stranded HCV RNA was examined by specific nest RT-PCR.IPHH expressed liver-associated proteins but did not express alpha-fetoprotein. Also IPHH showed ammonia removal activity. With regard to its malignant potential, colony formation in soft agar assay was not observed. Next, positive and negative stranded HCV RNAs in IPHH infected with patient's sera plus liver tissue homogenates were clearly detected whereas those in IPHH infected with only patient's sera were not detected.These results demonstrated the phenotypic characteristics of IPHH and the feasibility in vitro culture system of HCV infected human samples. This system might be useful for study of pathogenesis of HCV infection or hepatocyte-based applications.

Liver cirrhosis is one of the major complications of hepatitis C virus (HCV) infection, but the mechanisms underlying HCV-related fibrogenesis are still not clear. Although the roles of HCV core protein remain poorly understood, it is supposed to play an important role in the regulation of cellular growth and hepatocarcinogenesis. The aim of this study was to examine the role of HCV core protein on the hepatic fibrogenesis. We established an in vitro co-culture system with primary hepatic stellate cell (HSC) isolated from rats, and a stable HepG2-HCV core cell line which had been transfected with HCV core gene. The expressions of fibrosis-related molecules transforming growth factor beta1 (TGF-beta1), transforming growth factor beta receptor II (TGFbetaRII), alpha-smooth muscle actin (alpha-SMA) and connective tissue growth factor (CTGF) were analyzed via histological or molecular methods. In addition, the expression levels of matrix metaloprotinase-2 (MMP-2) and collagen type I (Col I) from the co-cultured media were measured by zymogram and ELISA, respectively. The expressions of alpha-SMA, TGF-beta1, Col I, TGFbetaRII and MMP-2 were significantly increased in the co-culture of stable HepG2-HCV core with HSC. Moreover, the significant increases of CTGF and TGF-beta1 in the HCV core-expressing cells were observed by either Northern or Western blot analysis. These results suggest that HCV core protein may contribute to the hepatic fibrogenesis via up-regulation of CTGF and TGF-beta1.

The extent of hepatic fibrosis is important in chronic liver disease. Liver biopsy is essential for diagnosis of fibrosis. However, biopsy is invasive and may not represent the whole liver state. Serum hyaluronic acid (HA), a major component of connective tissues, was introduced as a useful non-invasive index of hepatic fibrosis. The aim of this study was to evaluate the relationship among HA, the degree of fibrosis, several hematologic and biochemical parameters in patients with chronic liver diseases or post state liver transplantation (PSLT).Total 102 cases were divided into 4 groups: 57 chronic hepatitis (CH), 12 cirrhosis, 21 hepatocellular carcinoma (HCC), 12 PSLT. HA was measured by enzyme-linked binding protein assay and evaluated in relation the degree of fibrosis, several hematologic and biochemical parameters.Among four groups, HCC showed the highest HA and HA of HCC significantly higher than that of CH. The degree of fibrosis were correlated with HA. HA was correlated with age, platelet count and albumin but, not with ALT and PT. There is no significant relation between HA and the presence of acute rejection in liver transplantation.In chronic liver diseases, HA is a useful non-invasive index of hepatic fibrosis and disease severity.

The study of liver fibrogenesis by hepatitis C virus (HCV) has been limited due to the lack of an efficiency in vitro culture systems. In the present study, we investigated whether or not HCV core protein is directly related to liver fibrogenesis through stimulation of hepatic stellate cells (HSC).Human and rat HSC were isolated and we established an in vitro co-culture system of a stable HepG2-HCV core cell line which was transfected with HCV core gene and primary HSC. We performed immunocytochemical staining and Western and Northern blot analysis in the stimulated HSC by HCV core protein to identify the expression of transforming growth factor beta1 (TGF-beta1), transforming growth factor beta receptor II (TGFbeta R II), alpha-smooth muscle actin (alpha-SMA) and connective tissue growth factor (CTGF). The expression of matrix metalloproteinase-2 (MMP-2) and collagen type I (Col I) in the culture media were measured by zymogram and ELISA, respectively.The expression of TGF-beta1 and CTGF was significantly higher in the stable HepG2-HCV core cell line than in HepG2 cells. Furthermore, the makers related to fibrosis such as alpha-SMA, TGF-beta1, Col I, TGFRII and MMP-2 were highly expressed in the co-culture of stable HepG2-HCV core with HSC.HCV core protein may play a direct role in the fibrogenesis of chronic liver disease with HCV infection.