• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.281-284
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• 2002

Specific pathogen free (SPF) eggs have been used to produce live vaccines. however, their application causes many problems such as cost, space and waste disposal. The substitution of mammalian cells for SPF eggs offers a desirable system of vaccine production. In this study, mammalian cells were tested for the infection of Newcastle disease virus (NDV). As a result, DF-I and MDBK cells showed high virus productivity compared to the other mammalian cells. For the highest productivity of NDV, the optimal multiplicity of infection (M.O.I.) in DF-I or MDBK cells was determined to be 0.2 or 0.5 M.O.I., respectively.

• Korean Journal of Environmental Biology
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• v.29 no.1
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• pp.74-80
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• 2011

In this study we present a mammalian cell culture model that allows to study the effect of endocrine disruptors (EDCs) on aromatase activity of aquatic amphibian, Bombina orientalis. Bombina orientalis aromatase gene was subcloned into a mammalian expression vector and subsequently transfected to mammalian cells. Although the protein expression level of Bombina orientalis aromatase was low, it had a significant aromatase activity. When EDCs were added to aromatase transfected cells, aromatase activity was significantly decreased. We report here that this system may be used to monitor the effect of EDCs on aromatase activity of aquatic organisms.

• Animal cells and systems
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• v.5 no.3
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• pp.225-229
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• 2001

Nek2 is a mammalian protein kinase that is structurally homologous to NIMA, a mitotic regulator in Aspergillus nidulans. To understand cellular processes in which Nek2 participates during mammalian development, we investigated the expression and subcellular localization of Nek2 in vivo. The Nek2 protein was detected in spermatocytes and in a fraction of actively dividing ovarian follicle cells and of embryonic tissues. We also observed that Nek2 was localized in both the nucleus and centrosome in embryonic cells. Such localization pattern supports the proposal that Nek2 is a mitotic regulator that is involved in multiple cell cycle events during mammalian development.

• Molecules and Cells
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• v.24 no.2
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• pp.294-300
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• 2007

The mammalian glycosylphosphatidylinositol (GPI) anchor consists of three mannoses attached to acylated GlcN-(acyl)PI to form $Man_3$-GlcN-(acyl)PI. The first of the three mannose groups is attached to an intermediate to generate Man-GlcN-(acyl)PI by the first mannosyltransferase (GPI-MT-I). Mammalian and protozoan GPI-MT-I have different substrate specificities. PIG-M encodes the mammalial GPI-MT-I which has 423 amino acids and multiple transmembrane domains. In this work we cloned PIG-M homologues from humans, Plasmodium falciparum (PfPIG-M), and Saccharomyces cerevisiae (GPI14), to test whether they could complement GPI-MT-I-deficient mammalian cells, since this biosynthetic step is likely to be a good target for selective screening of inhibitors against many pathogenic organisms. PfPIG-M partially restored cell surface expression of the GPI-anchored protein CD59 in PIG-M deficient mammalian cells, and first mannose transfer activity in vitro; however, this was not the case for GPI14.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.1989-1996
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• 2015

Ice-binding proteins (IBPs) can inhibit ice recrystallization (IR), a major cause of cell death during cryopreservation. IBPs are hypothesized to improve cell viability after cryopreservation by alleviating the cryoinjury caused by IR. In our previous studies, we showed that supplementation of the freezing medium with the recombinant IBP of the Arctic yeast Glaciozyma sp. (designated as LeIBP) could reduce post-thaw hemolysis of human red blood cells and increase the survival of cryopreserved diatoms. Here, we showed that LeIBP could improve the viability of cryopreserved mammalian cells. Human cervical cancer cells (HeLa), mouse fibroblasts (NIH/3T3), human preosteoblasts (MC3T3-E1), Chinese hamster ovary cells (CHO-K1), and human keratinocytes (HaCaT) were evaluated. These mammalian cells were frozen in dimethyl sulfoxide (DMSO)/fetal bovine serum (FBS) solution with or without 0.1 mg/ml LeIBP at a cooling rate of -1℃/min in a -80℃ freezer overnight. The minimum effective concentration (0.1 mg/ml) of LeIBP was determined, based on the viability of HeLa cells after treatment with LeIBP during cryopreservation and the IR inhibition assay results. The post-thaw viability of mammalian cells was examined. In all cases, cell viability was significantly enhanced by more than 10% by LeIBP supplementation in 5% DMSO/5% FBS: viability increased by 20% for HeLa cells, 28% for NIH/3T3 cells, 21% for MC3T3-E1, 10% for CHO-K1, and 20% for HaCaT. Furthermore, addition of LeIBP reduced the concentrations of toxic DMSO and FBS down to 5%. Therefore, we demonstrated that LeIBP can increase the viability of cryopreserved mammalian cells by inhibiting IR.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.448-454
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• 1999

The regional distribution and relative frequency of the endocrine cells in the pancreas of the bean goose were investigated by immunohistochemical methods using 6 types of the specific antisera. Spindle shaped serotonin-immunoreactive cells were detected in the exocrine portions. Spherical or spindle shaped glucagon-immunoreactive cells were observed in the exocrine and dark and mammalian type islets. In the dark type islets, numerous cells were dispersed throughout whole islets but they were located in the peripheral regions of the mammalian type islets. No glucagon-immunoreactive cells were detected in light type islets. Round or spherical shaped insulin-immunoreactive cells were observed in the exocrine and dark, light and mammalian type islets. They were observed in the exocrine regions with a few numbers. Extremely rare cells were detected in central portion of the dark type islets but moderate to numerous cells were found in the central regions of the mammalian and light type islets, respectively. Spherical or spindle shaped somatostatin-immunoreactive cells were observed in the exocrine and dark, light and mammalian type islets. A few single cells were detected in the exocrine portions. In the dark type islets, numerous cells were dispersed throughout whole islets but a few to moderate numbers of cells were located in the peripheral regions of the light and mammalian type islets. Moderate numbers of the bovine pancreatic polypeptide-immunoreactive cells were found in the exocrine portions with round, spherical or spindle shape. But no bovine Sp-1/chromogranin-immunoreactive cells were observed in this study.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.232-237
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• 1999

The relationship between structure and contractile activity was studied on the three neuropeptide $\gamma$ (mammalian-, bowfin-, shark-NP$\gamma$) that were synthesized by the solid-phase method. Circular dichroism spectra showed that mammalian-, bowfin- and shark-neuropeptide $\gamma$ took an unordered structure in buffer solution and artificial liposome. The intestinal motility response was investigated with guinea-pig ileum, rat duodenum and carp intestine. In case of carp intestine, contractile activity was as follows; bowfin-NP$\gamma$> shark-NP$\gamma$>mammalian-NP$\gamma$, On the other hand, the contractile activity of mammalian-neuropeptide $\gamma$ was more potent than those of bowfin-, shark-neuropeptide $\gamma$ in the guinea-pig ileum and rat duodenum. These results suggest that NP$\gamma$ show the species-specific activity.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.497-498
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• 2012

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.39-39
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• 2005

Large scale mammalian cell culture has become, over the past two decades, the preferred method to produce therapeutic monoclonal antibodies. In this presentation, I will introduce disposable bioreactor system and analyze key factors and points for consideration during mammalian cell culture process development. Example will be provided highlighting the selection of master cell, culture media and environmental factors based on productivity and product quality.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.189.2-189
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• 2001

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