• Journal of Life Science
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• v.17 no.1 s.81
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• pp.45-50
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• 2007

This study investigated biological activity of tumor necrosis factor $(TNF)-\alpha$ secreted from smooth muscle cell (SMC) destined for death by expressing Fas associated death domain containing protein (FADD) (FADD-SMC) when the cells are grown without tetracycline in culture medium. In the absence of tetracycline the FADD-SMC secreted approximately 1000 pg/ml $TNF-\alpha$, whereas hardly detectable amount of the cytokine existed in the presence of tetracycline. The culture medium collected from the FADD-SMC grown in the absence of tetracycline increased phosphorylated form of p38 MAPK and up-regulated nuclear factor kappa B (NF-kB). The medium collected without tetracycline also caused death of L929 cells. Depletion of $TNF-\alpha$ with the soluble TNF receptor (sTNFR) inhibited the phosphorylation of p38 MAPK, the up-regulation of NF-kB activity and the death activity of the medium collected from FADD-SMC in the absence of tetracycline. These results indicate that $TNF-\alpha$ secreted from SMC undergoing death is biologically active and can affect cellular function.

• The Journal of Society for e-Business Studies
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• v.9 no.1
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• pp.221-235
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• 2004

Many organizations are implementing Knowledge Management(KM) technologies to promote knowledge sharing. An extensive review of recent articles and journals about such implementations reveals that one of the main barriers to implementation of KM technology is the absence of an organizational culture that supports knowledge sharing. The purpose of this research is to explore the possible relationship between the successful implementation of knowledge management technology and specific organizational culture attributes. The Organizational Culture Profile(OCP) and the Knowledge Management Technology Profile(KMTP) instruments were used to identify and rank the most critical organizational culture attributes and KM technology implementation successes. Data were collected from twenty six US organizations involved in a KM efforts.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.05a
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• pp.14-23
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• 2002

Development of oligodendrocytes and the generation of myelin internodes within the spinal cord depends on regional signals derived from the notochord and axonally derived signals. Neuregulin (NRG)-1, localized in the floor plate as well as in motor and sensory neurons, is necessary for normal oligodendrocyte development. Oligodendrocytes respond to NRGs by activating members of the erbB receptor tyrosine kinase family. Here, we show that erbB2 is not necessary for the early stages of oligodendrocyte precursor development, but is essential for proligodendroblasts to differentiate into galactosylcerebroside-positive (GalC+) oligodendrocytes. In the presence of erbB2, oligodendrocyte development is normal. In the absence of erbB2 (erbB2-/-), however, oligodendrocyte development is halted at the proligodendroblast stage with a >10-fold reduction in the number of GalC+ oligodendrocytes. ErbB2 appears to function in the transition of proligodendroblast to oligodendrocyte by transducing a terminal differentiation signal, since there is no evidence of increased oligodendrocyte death in the absence of erbB2. Furthermore, known survival signals for oligodendrocytes increase oligodendrocyte numbers in the presence of erbB2, but fail to do so in the absence of erbB2. Of the erbB2-/- oligodendrocytes that do differentiate, all fail to ensheath neurites. These data suggest that erbB2 is required for the terminal differentiation of oligodendrocytes and for development of myelin.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.10a
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• pp.47.1-47
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• 2001

One of the problems associated with in vitro culture of primordial gern cells (PGCs) is the large loss of cells during the initial period of culture. This study characterized the initial loss and determined the effectiveness of two classes of apoptosis inhibitors, protease inhibitors and antioxidants, on the ability of the porcine PGCs to survive in culture. Results from electron microscopic analysis and in situ DNA fragmentation assay indicated that porcine PGCs rapidly undergo apoptosis when placed in culture. Additionally, \ulcorner2-macroglobulin, a protease inhibitor and cytokine carrier, and N-acetylcysteine, an antioxidant, increased the survival of PGCs in vitro. While other protease inhibitors tested did not affect survival of PGCs, all antioxidants tested improved survival of PGCs (p<0.05). Further results indicated that the beneficial effect of the antioxidants was critical only during the initial period of culture. Finally, it was determined that in short-term culture, in the absence of feeder layer, antioxidants could partially replace the effect(s) of growth factors and reduce apoptosis. Collectively, these results indicate that the addition of \ulcorner2-macroglobulin and antioxidatns can increase the number of PGCs in vitro by suppressing apoptosis.

• Proceedings of the KSAR Conference
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• 2001.10a
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• pp.47-47
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• 2001

One of the problems associated with in vitro culture of primordial germ cells (PGCs) is the large loss of cells during the initial period of culture. This study characterized the initial loss and determined the effectiveness of two classes of apoptosis inhibitors, protease inhibitors and antioxidants, on the ability of porcine PGCs to survive in culture. Results from electron microscopic analysis and in situ DNA fragmentation assay indicated that porcine PGCs rapidly undergo apoptosis when placed in culture. Additionally,？ 2-macroglobulin, a protease inhibitor and cytokine carrier, and N-acetylcysteine, an antioxidant, increased the survival of PGCs in vitro. While other protease inhibitors tested did not affect survival of PGCs, all antioxidants tested improved survival of PGCs (p〈0.05). Further results indicated that the beneficial effect of the antioxidants was critical only during the initial period of culture. Finally, it was determined that in short-term culture, in the absence of feeder layers, antioxidants could partially replace the effect(s) of growth factors and reduce apoptosis. Collectively, these results indicate that the addition of ？2-macroglobulin and antioxidants can increase the number of PGCs in vitro by suppressing apoptosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.1
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• pp.40-45
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• 1991

The release of hepatic triglyceride lipase from cultured rat hepatocytes and its hormonal regulation were studied. The activity of lipase released into the medium in the presence of heparin was increasing during 24 hours on the 2nd of culture while this was 10% in the absence of heparin as compared with the lipase activity in the presense of heparin. When hepatocytes were cultured with anti-hepatic triglyceride lipase lgG the lipase activity was supp-ressed by 92% The results suggest that the enzyme relaeased into culture medium is identical to hepatic triglyceride lipase which can be released only in the presence of heparin the model of release being similar to that of lipoprotein lipase from adipocytes. The addition of monensin to the medium resulted in The inhibition of lipase secretion by 61% Insulin enhanced lipase activity only 20% whereas dexamethasone suppressed the activity by 44% These data inidica-ted that hepatic triglyceride lipase is secreted and released from hepatocytes in the presence of heparin and its secretion is regulated by hormones.

• Journal of Microbiology
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• v.42 no.1
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• pp.37-41
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• 2004

The textile industry wastewater has been decolorized efficiently by the white rot fungus, Irpex lacteus, without adding any chemicals. The degree of the decolorization of the dye effluent by shaking or stationary cultures is 59 and 93%, respectively, on the 8th day. The higher level of manganese-dependent peroxidase (MnP) and non-specific peroxidase (NsP) was detected in stationary cultures than in the cultures shaken. Laccase activities were equivalent in both cultures and its level was not affected significantly by the culture duration. Neither lignin peroxidase (LiP) nor Remazol Brilliant Blue R oxidase (RBBR ox) was detected in both cultures. The absorbance of the dye effluent was significantly decreased by the stationary culture filtrate of 7 days in the absence of Mn (II) and veratryl alcohol. In the stationary culture filtrate, three or more additional peroxidase bands were detected by the zymogram analysis.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.247-253
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• 2005

The bacterial cellulose (BC) production by a wild­strain Acetobacter xylinum BPR2001 and that by its acetan­nonproducing mutant, EPI, were compared in a jar fermentor. EPI produced about $28\%$ less BC than the wild-strain. The apparent difference in the cultivation of the two strains was the viscosity increase in the culture broth that was closely associated with acetan production. Increasing the viscosity of the culture broth of EPI by adding agar led to the formation of relatively small and uniform BC pellets, and BC production consequently became two-fold higher than that in the absence of agar and was almost equal to that by BPR2001. Therefore, acetan has an important role in BC production by inducing physical changes in the culture broth of the wild-type strain.

• YAKHAK HOEJI
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• v.24 no.3_4
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• pp.143-150
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• 1980

The effect of ginseng saponin on chick embryonic dorsal root ganglia organ culture and brain, spinal cord, muscle dissociation cultures was studied. The fiber outgrowth in explanted chick embryonic dorsal root ganglia was markedly induced by water and alcohol extracts of ginseng, total ginseng saponin, protopanaxadiol and protopanaxatriol glycosides as well as ginsenosides R/sub b1/, R/sub d/, R/sub 0/+R/sub a/+R/sub b1/, and R/sub b2/+R/sub c/+R/sub e/ mixtures. The life span of the cultured chick embryonic dorsal root ganglia and potentiation of nerve cell density were also observed with all of these ginseng saponins. The effect of ginseng saponin on chick embryonic dorsal root ganglia organ culture was more marked in the absence of the chick embryonic extract which was known to contain nerve growth factor-like material in the culture media. However, the ginseng saponin did not influence the cultured central nervous system such as brain and spinal cord cells and cultured skeletal muscle cells with respect to the morphological changes, maturation and life span of these cells.

• Journal of Microbiology and Biotechnology
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• v.5 no.2
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• pp.96-99
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• 1995

Addition of l00mM $MgSO_4$ to a cell culture after 54 hours resulted in a 2.4-fold increase in the sisomicin titre compared to a control to which no $MgSO_4$ was added, and a considerable amount of intracellular sisomicin was liberated outside the cells. The occurrence of product inhibition in fermentation was confirmed by a reduction in net sisomicin production with increasing amounts of added sisomicin without addition of $MgSO_4$. All added sisomicin was bound to sisomicin-free cells in the absence of $MgSO_4$, whereas approximately 40% of added sisomicin was bound with the addition of l00mM $MgSO_4$. Under conditions of no enzmye synthesis, maintained by adding chloramphenicol to exclude product repression, sisomicin was produced in the presence of 100 mM $MgSO_4$ but little sisomicin was produced in the absence of $MgSO_4$.