Biomedical subjects

Eun Jeong Kim

Publications and source records attributed to Eun Jeong Kim.

13 recordsLinked to original sources

PubMed2006

Enhancement of recombinant protein production in Chinese hamster ovary cells through anti-apoptosis engineering using 30Kc6 gene.

It was previously reported that silkworm hemolymph (SH) inhibits apoptosis and increases the production of recombinant human erythropoietin (EPO) in Chinese hamster ovary (CHO) cells. The apoptosis-inhibiting component in SH is a member of 30K protein family. In this study, the CHO cell line producing EPO was manipulated genetically to express the 30Kc6 gene encoding a 30K protein in the hemolymph of the silkworm, Bombyx mori. The transient expression of 30Kc6 significantly suppressed the cell death induced by serum deprivation. A stable cell line expressing 30Kc6 with an anti-apoptotic property was established. The stable expression of 30Kc6 inhibited serum-deprivation-induced apoptosis and increased the cell density and EPO titer by 5- and 10-fold, respectively. The positive effects of the 30Kc6 expression on cell viability and productivity were due to the stable maintenance of the mitochondrial activity. The 30Kc6 expression efficiently suppressed the depolarization of the mitochondrial membrane and subsequently balanced the generation/consumption of ATP. The use of the 30Kc6 gene is expected to provide a new method of host cell engineering for improving the productivity of the recombinant protein.

Animals↗

PubMed2006

In vitro and in vivo gene-transferring characteristics of novel cationic lipids, DMKD (O,O'-dimyristyl-N-lysyl aspartate) and DMKE (O,O'-dimyristyl-N-lysyl glutamate).

We chemically synthesized two different cationic lipids consisting of a core of lysine, two C-14 hydrocarbon chains, and either aspartatic acid or glutamic acid. The lipids were assigned the acronyms, DMKD and DMKE. Cationic liposomes prepared with the two different lipids were tested for their gene-transferring capabilities in various cell lines compared with that of control DOTAP liposomes. Under the same experimental conditions, the order of in vitro gene transfection efficiency was DMKE>or=DMKD>DOTAP. To identify the parameters influencing transfection efficiency, the DNA-binding affinities of the liposomes were compared and changes in particle size and surface charge were examined after complex formation. Both the DNA-binding affinity of the liposomes and the cell surface-binding affinity of the liposome-pDNA complexes were crucial for gene transfection. In addition, intravenously administered DMKE and DMKD liposomes exhibited different biodistribution characteristics and intensity of in vivo organ transfection from the DOTAP liposomes. Compared to the DOTAP liposomes, they were more readily transferred to the liver. Interestingly, when they were directly injected into tumor tissues, the DMKE lipoplexes were able to induce more efficient transgene expression in these tissues than the DOTAP and DMKD lipoplexes. This study suggests that a small difference in the cationic lipid backbone structure significantly affects gene-transferring capabilities. DMKE and DMKD liposomes can be utilized as efficient gene-transferring vehicles for hepatic or intra-tumoral gene transfection.

Animals↗

PubMed2005

Inhibitory activity of isorhamnetin from Persicaria thunbergii on Farnesyl Protein Transferase.

The methanolic extract of the aerial parts of Persicaria thunbergii was found to show inhibitory activity on Farnesyl Protein Transferase (FPTase). Bioassay-guided fractionation of the methanolic extract resulted in the isolation of isorhamnetin, as an inhibitor on FPTase. This compound inhibited FPTase activity in a dose-dependent manner, and the IC50 value of isorhamnetin was 37.5 microM.

Alkyl and Aryl Transferases↗

PubMed2005

Combined effects of bovine colostrum and glutamine in diclofenac-induced bacterial translocation in rat.

BACKGROUND AND AIMS: The aim of this study was to examine whether the combined administration of bovine colostrum and glutamine was able to prevent the non-steroidal anti-inflammatory drug (NSAID)-induced gut damage and bacterial translocation (BT) in the rats. METHODS: The animal model population of the study consisted of six groups; control group, diclofenac group, diclofenac with milk group, diclofenac with colostrum group, diclofenac with glutamine group and diclofenac with colostrum and glutamine group. The animals with milk, colostrum or glutamine were fed with low fat milk, liquid colostrum or glutamine by orogastric gavage for 5 days before the diclofenac administration. Intestinal permeability, serum biochemical profiles and intestinal adhesion for assessment of the gut damage, and enteric bacterial overgrowth and BT at the mesenteric lymph nodes, liver, spleen and systemic blood were measured. RESULTS: Diclofenac caused the increase in gut damage, enteric bacterial numbers and BT. Supplements with colostrum or glutamine reduced these changes induced by diclofenac, but this result was not seen for supplementation with low fat milk. Combined administration of colostrum and glutamine reduced diclofenac-induced gut damage and BT as compared to the use of bovine colostrum alone or glutamine alone. CONCLUSIONS: This study suggested that the combined administration of bovine colostrum and glutamine might effectively reduce NSAID-induced gut damage and BT in the rat.

Animals↗

PubMed2005

[Emergency nurse-patient interaction behavior].

PURPOSE: The main purpose of this study was to explore nurse-patient interaction behaviors and patient satisfaction with the interaction in the emergency department. METHOD: This study used video technology to record complete conversations between the nurse and patient, thus obtaining the interactions naturally occurring in a clinical setting. The participants were 28 nurses and 63 patients in the emergency department at one university hospital located in Seoul. The data was collected from November, 2002 to April, 2003. The video recordings were observed for 4 hours for each case and coded using an adapted version of Roter's Interaction Analysis System (RIAS), which yields frequencies of thirty-six types of interaction behaviors. RESULT: The information exchange related to therapeutic items including medications, simple orientation, and situational positive talk were characterized in the nurses' interaction behaviors. Giving information about one's own condition, questions about therapeutic regimen, and showing worry were characterized in patient interaction behaviors. The patients' satisfaction with the interaction was 37.75.9 (range 9-45). CONCLUSION: The emergency nurse-patient interaction behavior was task-related. The results suggest that identification of effective interaction behavior in the Emergency department and an interaction skill training program could increase patient satisfaction.

Adult↗

PubMed2005

Protective effects of bovine colostrum on non-steroidal anti-inflammatory drug induced intestinal damage in rats.

The aim of this study was to examine whether bovine colostrum was able to prevent the NSAID induced small intestinal damage in animals. The animal model population of the study consisted of 4 groups: control group, diclofenac group, diclofenac with 10% low fat milk group and diclofenac with 5% colostrum group. The animals with milk or colostrum were fed with 10% low fat milk or 5% colostral solution for 5 days before the administration of diclofenac. Gut injuries were induced by administration of a single dose of diclofenac (100 mg/kg orally). Epithelial permeability values (24 hour urinary excretion of 51Cr-ethylenediaminetetraacetic acid [51Cr-EDTA]), enteric aerobic bacterial counts, serum biochemical profiles and pathologic findings of distal ileum were measured. Diclofenac caused a marked increase in the intestinal permeability, enteric bacterial numbers and intestinal villous damage, and enteric protein and albumin loss. Combined administration of bovine colostrum reduced the increase in intestinal permeability, enteric bacterial overgrowth, protein losing enteropathy and mucosal villous damage of the small intestine induced by diclofenac. Bovine colostrum may have a beneficial effect in prevention of NSAID induced small intestinal injuries.

Animals↗

PubMed2004

Characterization of the metabolic flux and apoptotic effects of O-hydroxyl- and N-acyl-modified N-acetylmannosamine analogs in Jurkat cells.

The supplementation of the sialic acid biosynthetic pathway with exogenously supplied N-acetylmannosamine (ManNAc) analogs has many potential biomedical and biotechnological applications. In this work, we explore the structure-activity relationship of Man-NAc analogs on cell viability and metabolic flux into the sialic acid biosynthetic pathway to gain a better understanding of the fundamental biology underlying "glycosylation engineering" technology. A panel of ManNAc analogs bearing various modifications on the hydroxyl groups as well as substitutions at the N-acyl position was investigated. Increasing the carbon chain length of ester derivatives attached to the hydroxyl groups increased the metabolic efficiency of sialic acid production, whereas similar modification to the N-acyl group decreased efficiency. In both cases, increases in chain length decreased cell viability; DNA ladder formation, Annexin V-FITC two-dimensional flow cytometry assays, caspase-3 activation, and down-regulation of sialoglycoconjugate-processing enzymes established that the observed growth inhibition and toxicity resulted from apoptosis. Two of the panel of 12 analogs tested, specifically Ac(4)ManNLev and Ac(4) ManNHomoLev, were highly toxic. Interestingly, both of these analogs maintained a ketone functionality in the same position relative to the core monosaccharide structure, and both also inhibited flux through the sialic acid pathway (the remainder of the less toxic analogs either increased or had no measurable impact on flux). These results provide fundamental insights into the role of sialic acid metabolism in apoptosis by demonstrating that ManNAc analogs can modulate apoptosis both indirectly via hydroxylgroup effects and directly through N-acyl-group effects.

Apoptosis↗

PubMed2004

[Intestinal permeability in patients with viral and alcoholic liver disease].

BACKGROUND/AIMS: Increased intestinal permeability has been possible contributing factors to the pathogenesis of alcoholic liver disease. Moreover, it can contribute to the development of bacterial infection and intestinal endotoxemia in patients with liver cirrhosis. This study aimed to examine the difference of intestinal barrier dysfunction between alcoholic and viral liver disease patients through the comparison of the intestinal permeabilities of patients with clinical characteristics. METHODS: Intestinal permeabilities were measured in 18 healthy controls, 41 patients with alcoholic liver disease (17 cases of alcoholic liver disease without cirrhosis and 24 cases of alcoholic liver cirrhosis) and 46 patients with viral liver disease (14 cases of chronic viral hepatitis and 32 cases of viral liver cirrhosis) by measuring 24 hour urine excretion of 51Cr-EDTA. RESULTS: The intestinal permeability was significantly increased in the patients with alcoholic liver disease without cirrhosis (5.62 +/- 2.80%), alcoholic liver cirrhosis (5.29 +/- 2.48%) and viral liver cirrhosis (3.15 +/- 1.39%) compared with that in control subjects (1.99 +/- 0.53%). On the contrary, it was not increased in the patients with chronic viral hepatitis (2.05 +/- 0.57%) versus controls. The significant correlation was not found between intestinal permeability and clinical and laboratory findings. CONCLUSIONS: The intestinal permeability was elevated in patients with alcoholic liver disease compared to those with viral liver cirrhosis. The pathophysiology of liver injury secondary to intestinal epithelial damage may be different between alcoholic and viral liver diseases.

Aged↗

PubMed2003

Inhibition of apoptosis by recombinant 30K protein originating from silkworm hemolymph.

In a previous study, we reported that silkworm hemolymph inhibits apoptosis and that the anti-apoptotic component in silkworm hemolymph is a 30K protein. In this study, the 30K protein encoded by 30Kc6 was expressed in Escherichia coli. The recombinant 30K protein was expressed as an inclusion body, and the inclusion body was separated and refolded by affinity column chromatography using a 6xHis tag. We demonstrated that apoptosis is inhibited by supplementing the culture medium with this purified recombinant 30K protein. The recombinant 30K protein inhibited the virus- or chemical-induced apoptosis in human cells as well as insect cells. Apoptosis-inhibitory activity of recombinant 30K protein was comparable to that of whole silkworm hemolymph. The recombinant 30K protein can be effectively used to minimize cell death and consequently increase the productivity by extending the production time of host cells in commercial animal cell culture.

Amino Acid Sequence↗

PubMed2002

Silkworm hemolymph as a potent inhibitor of apoptosis in Sf9 cells.

We have previously shown that silkworm hemolymph exhibits anti-apoptotic activity against baculovirus-induced Sf9 cell apoptosis. In this study, using various chemical inducers, such as actinomycin D, camptothecin, and staurosporine, we found that silkworm hemolymph inhibits insect cell apoptosis induced not only by baculovirus but also by chemical inducers. This indicates that silkworm hemolymph contains anti-apoptotic components that work directly in insect cell apoptosis without any booster expression of baculoviral genes. With the analysis of Sf-caspase-1 activity, it was found that the inhibitory effect of silkworm hemolymph works in a further upstream step than the Sf-caspase-1 activation step.

Animals↗

PubMedDate not supplied

Inhibition of apoptosis by a Bombyx mori gene.

An apoptosis-inhibiting component of silkworm hemolymph, isolated and characterized in our previous study, showed 95% N-terminal amino acid sequence homology with one of the 30K proteins, a group of structurally related proteins. The 30K protein was expressed in mammalian HEK293 cells and CHOK1 cells by transfection with 30Kc6. The expression of 30Kc6 inhibited apoptosis comparably to that of whole silkworm hemolymph, indicating that both intracellular expression and external supplementation inhibited apoptosis. The expression of 30Kc6 resulted in lower intracellular activity for caspase 3. However, the results of in vitro assay of caspase 3 show that the 30Kc6 protein does not inhibit caspase 3 activity. This indicates that the 30Kc6 protein inhibits the apoptosis by working in a further upstream event than caspase 3 activation.

Animals↗

PubMedDate not supplied

Establishment of N-acetylmannosamine (ManNAc) analogue-resistant cell lines as improved hosts for sialic acid engineering applications.

Metabolic substrate-based sialic acid engineering techniques, where exogenously supplied N-acetylmannosamine (ManNAc) analogues are utilized by the sialic acid biosynthetic pathway, allow the cell surface to be endowed with novel physical and chemical properties and show promise for increasing the quality of recombinant glycoproteins. The in vitro toxicity of many ManNAc analogues, however, hinders the large-scale adoption of this technology. In this study, we used a selection strategy where cells were subjected to progressively higher levels of ManNAc analogues to establish novel cell lines that showed decreased sensitivity to analogue-induced in vitro toxicity. The decreased sensitivity to sugar analogue-induced apoptosis, demonstrated by the Annexin V-FITC detection method and DNA fragmentation assays, corresponded to increased sialic acid production in the resistant cell lines. The ManNAc analogue-resistant cell lines exhibited cross-resistance to apoptosis induced by staurosporine and an apoptosis-activating Fas antibody. We propose that the selection strategy employed to develop these novel cell lines, which serve as superior hosts for substrate-based sialic acid engineering applications, will generally apply to the development of host cell lines for biotechnology applications.

Apoptosis↗

PubMedDate not supplied

Comparison of risk factors between prehypertension and hypertension in Korean male industrial workers.

OBJECTIVES: To compare risk factors for prehypertension and hypertension in male industrial workers in Korea. SAMPLE: Participants included 2,476 males aged 19-56 years who were employed in an airplane manufacturing industry. METHODS: Health records of all subjects were analyzed during a biennial employee physical checkup that included a health survey questionnaire and blood tests. RESULTS: Forty-six percent of subjects had prehypertension and 15% had hypertension. Multivariate logistic regression analysis showed that, after adjustment for age, workplace, and risk variables, subjects who were currently alcohol drinkers, in blue collar jobs, body mass index (BMI) > or =25 kg/m(2), and had cholesterol > or =201 mg/dl were 1.30, 1.28, 1.27, and 1.21 times more likely to have prehypertension respectively, compared with normotensives. Subjects with FBS> or =121 mg/dl, BMI> or =25 kg/m(2), and age> or =40 years were 2.47, 1.52, and 1.36 times more likely to have hypertension respectively, compared with prehypertensive subjects. CONCLUSIONS: Nurses working in the industrial sector should focus on education and counseling regarding the risk factors for prehypertension and hypertension, and they should emphasize the importance of healthy lifestyles and curbing obesity to help arrest the progression of prehypertension to hypertension.

Adult↗