• KSBB Journal
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• v.22 no.5
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• pp.356-361
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• 2007

Cyanobacteria are a very old group of prokaryotic organisms that produce very diverse secondary metabolites, especially non-ribosomal peptide and polyketide structures. Although some cyanobacteria produce lethal toxins such as microcystins and anatoxins, some may be useful either for development into commercial drugs or as biochemical tools. Detection of unknown secondary metabolites was carried in the present study by a screening of 98 cyanobacterial strains from Cyanobiotech GmbH in order to establish a screening process, isolate pure substances and determine their bioactivities. A degenerated polymerase chain reaction technique as molecular approaches has been used for general screening of NRPS gene and PKS gene in cyanobacteria. A putative PKS gene was detected by DKF/DKR primer in 38 strains (38.8%) and PCR amplicons resulted from a presence of NRPS gene were showed by MTF2/MTR2 primer in 30 strains (30.6%), respectively. A screening of interesting strains was performed by comparing PCR screening results with HPLC analyses of extracts. HPLC analysis for a detection of natural products was performed in extracts from biomass. 5 strains were screened for further scale-up processing. 7 pure substances were isolated from the scale-up cultures and tested for bioactivities under consideration to purity, amount and molecular weight of substances. One substance isolated from CBT 635 showed cytotoxic activity. This substance may be regarded as Microcystin LR.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.474-480
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• 2004

The purpose of this in vitro study was to compare the remineralizing effects of three glass ionomer cements (high filled glass ionomer cement, compomer, resin modified glass ionomer cement) with resin composite (control group) on incipient interproximal caries, and to assess long-term change of remineralization effect, in each material, evaluated by microtomography. Proximal restoration was simulated with tooth specimen and Glass Ionomer Cements. And each of these groups was placed into a closed container with artificial saliva at $37^{\circ}C$ and pH 7.0 for a time period of thirty days with constant circulation. At the end of thirty and sixty days, tomographic images were taken from these specimens with micro CT scanner. Materials used in this study were as follows. Group 1: Fuji IX GP (GC Corp., Tokyo, Japan) Group 2: Vitremer (3M ESPE, St. Paul, Minn., USA) Group 3: F2000 (3M ESPE, St. Paul, Minn., USA) Group 4: Z250 (3M ESPE, St. Paul, Minn., USA) Using density-measuring program, the micro-density of carious lesions on the specimens were measured. The mean density changes of each group were compared to the other groups to evaluate the effect of remineralization. The results were as follows: 1. The lesion density of all groups increased. 2. The mean density increase of Group 1, 2, 3 were higher than that of Group 4 every month(p<0.05). 3. There were significant differences of density increase among glass ionomer group(Group 1, 2, 3).

• Journal of Life Science
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• v.20 no.10
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• pp.1519-1524
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• 2010

Apigenin (4', 5, 7-trihydroxyflavone), a common dietary flavonoid abundantly present in fruits and vegetables, has shown remarkable anti-proliferative effects against various malignant cell lines. To observe the anti-proliferative effects, oral cavity cancer cell lines, $6{\times}10^3$ cells/well (96 well plate) of KB oral cavity tumor cells were plated and 24 hr later treated with apigenin for one day, after which MTT assay was performed. Apigenin induced cell death in a dose-dependent manner after incubation. Cell viability was significantly decreased in the group treated with 100 ${\mu}M$ apigenin for 24 hr (p<0.05) compared to the control group. To assess apoptosis, the nuclei of KB cells were stained with DAPI. The presence of chromatin condensation in the apigenin treated cells was detected on a fluorescent microscope (${\times}200$). We investigated the in vivo growth inhibitory effects of apigenin on oral cavity cancer KB tumor xenograft subcutaneously implanted in male nude mice. Apigenin was administered to mice by gavage at doses of 25 and 50 mg/kg/day in 0.2ml of PBS. Tumor volume was significantly decreased in 25 and 50 mg/kg apigenin-administration groups compared to the control group. For apoptosis analysis, TUNEL staining was performed. A significant increase in TUNEL positive cells was found in the 25 mg/kg apigenin administration group compared to the non- apigenin administration group. Histopathological changes were not observed. These results indicate that apigenin inhibits oral cavity cancer cell growth through the induction of apoptosis.

• Journal of muscle and joint health
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• v.8 no.1
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• pp.122-140
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• 2001

The aims of this study were to understand and to predict the determinent factors affecting the exercise behaviors and physical fitness by testing the Pender's revised health promotion model, and to help the patients with rheumatoid arthritis and osteoarthritis perform the continous exercise program, and to help them maximize the physical effect such as muscle strength, endurance, and functional status and mental effects including self efficacy and quality of life, and improve the physical and mental well being, and to provide a basis for the nursing intervention strategies. Of the selected variables in this study, the endogenous variables included the physical fitness, exercise score, exercise participation, perceived benefits of action, perceived barriers of action to exercise, activity-related affect(depression) and perceived self-efficacy, interpersonal influences(family support), situational factors(duration of arthritis, fatigue) and the exogenous variables included personal sociocultural factor(education level), personal biologic factor(body mass index), personal psychologic factor(perceived health status) and prior related behavior factors(previous participation in exercise, life-style). We analyzed the clinical records of 208 patients with rheumatoid arthritis and degenerative arthritis who visited the outpatient clinics at H university hospital in Seoul. Data were composed of self reported qustionnaire and good of fitness score which were obtained by padalling the ergometer of bicycle for 9 minutes. SPSS Win 8.0 and Window LISREL 8.12a were used for statistical analysis. Of 75 hypothetical paths that influence on physical fitness, exercise participation, exercise score, perceived benefits of action, perceived barriers of action to exercise, activity-related affect(depression) and perceived self-efficacy, interpersonal influences(family support), situational factors(duration of arthritis, fatigue), 40 were supported. The physical fitness was directly influenced by life-style, perceived health status, education level, family support, fatigue, which explained 12% of physical fitness. The exercise participation were directly influenced by life-style, education level, past exercise behavior, perceived benefits of action, perceived barriers of action, depression and duration of arthritis, which explained 47% of exercise participation. Exercise score were directly affected by perceived self efficacy. BMI, life-style, past exercise behavior, perceived benefits of action, family support, perceived health status. perceived barriers of action, and fatigue, which explained 70%. Perceived benefits of action was directly influenced by BMI, life-style, which explained 39%. Perceived barriers of action were directly influeced by past exercise behavior, perceived health status, which explained 7%. Perceived self efficacy were directly influeced by level of education, perceived health status, life-style, which explained 57%. Depression were directly influeced by past exercise behavior, BMI, life-style, which explained 27%. Family support were directly influeced by life-style, perceived health status, which explained 29%. Fatigue were directly influeced by BMI, life-style, perceived health status. which explained 41%. Duration of arthritis were directly influeced by life-style, past exercise behavior, BMI, which explained 6%. In conclusion, important variables for physical fitness were life-style, and variable affecting exercise participation were life-style. Perceived self-efficacy of exercise was a significant predictor of exercise score. BMI, Life-style, perceived benefits of action, family support, past exercise behavior showed direct effects on perceived self-efficacy. Therefore, disease related factor should be minimized for physical performance and well being in nursing intervention for patients with rheumatoid arthritis, and plans to promote and continue exercise should be seeked to reduce disability. In addition, Exercise program should be planned and performed by the exact evaluation of exercise according to the ability of the patients and the contents to improve the importance of exercise and self efficacy in self control program, dedicated educational program should be involved. This study suggest that the methods to reduce the disease related factors, the importance of daily life-style, recognition of benefit of exercise, and educational program to promote self efficacy should be considered in the exercise behavior promotion and nursing intervention for continous performance. The significance of this study is also thought to provide patients with chronic arthritis the specific data for maximal physical and mental well being through exercise, chronic therapeutic procedure, daily adaptation and confrontation in nursing intervention.

• Korean Journal of Poultry Science
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• v.35 no.1
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• pp.71-78
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• 2008

This study was conducted to investigate the effects of dietary supplementation of herbs and plant extracts (PE) on the performance, small intestinal microflora and immune response in laying hens. A total of 1,440 Hy-Line Brown laying hens of 67 wks old were assigned to one of the following 9 dietary treatments : T1 : Control (C), T2 : C + Avilamycine 6 ppm, T3 : C + Herb $Mix^{(R)}$ 0.2%, T4 : C + Biostrong $510^{(R)}$ 0.02%, T5 : C + $APEX^{(R)}$ 0.02%, T6 : C + $Digestarom^{(R)}$ 0.02%, T7 : C + $Phellozyme^{(R)}$ 0.1%, T8 : C + $Galicin^{(R)}$ 0.05%, T9 : C + CRINA $Poultry^{(R)}$ 0.05%. Each treatment was replicated 8 times with twenty birds housed in 2 bird cages. Twenty bird units were arranged according to completely randomized block design. Feeding trial lasted 6 wks under 16 hours lighting regimen. Hen-day egg production was not significantly different among the treatments, but that of supplemented groups tended to be higher than the control. There were significant differences among treatments in feed intake and feed conversion ratio. Feed intake was higher in the supplemented groups than the control. Feed conversion ratio was higher in T8 than other treatments. Egg shell color index and egg yolk color index were significantly different among treatments. Egg shell color was affected by supplements and egg yolk color index of T9 (PE-CRINA) was significantly higher than the control. Haugh unit was not significantly different among treatments. There were significant differences in leukocytes and erythrocytes parameters. The level of serum WBC and stress index (heterophil/lymphocyte) were higher in supplemented groups than the control. The level of RBC tended to be lower in the herb or PE groups than the control. The concentration of serum IgG was not significantly different among the treatments, but all those of the supplemented groups were higher than the control. The number of Lactobacilli spp. tended to increase and that of Cl. perfrigens decrease in the supplemented groups. The number of E. coli significantly decreased in the supplemented groups. The results of this experiment showed that feeding herbs and plant extracts to laying hens tended to improve the egg production and affect positively on the level of blood parameters and small intestinal microflora.

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.253-258
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• 2004

Purpose: Chitosan has been studied as a non-viral gene delivery vector, drug delivery carrier, metal chelator, food additive, and radiopharmaceutical, among other things. Recently, galactose-graft chitosan was studied as a non-viral gene and drug delivery vector to target hepatocytes. The aim of this study was to investigate the usefulness of nuclear imaging for in vivo evaluation of targeting the hepatocyte by galactose grafting. Methods and Materials: Galactosyl methylated chitosan (GMC) was produced by methylation to lactobionic acid coupled chitosan. Cytotoxicity of $^{99m}Tc$-GMC was determined by MTT assay. Rabbits were injected via their auricular vein with $^{99m}Tc$-GMC and $^{99m}Tc$-methylated chitosan (MC), the latter of which does not contain a galactose group, and images were acquired with a gamma camera equipped with a parallel hole collimator. The composition of the galactose group in galactosylated chitosan (GC), as well as the tri-, di-, or mono-methylation of GMC, was confirmed by NMR spectroscopy. Results: The results of MTT assay indicated that $^{99m}Tc$-GMC was non-toxic. $^{99m}Tc$-GMC specifically accumulated in the liver within 10 minutes of injection and maintained high hepatic uptake. In contrast, $^{99m}Tc$-MC showed faint liver uptake. $^{99m}Tc$-GMC scintigraphy of rabbits showed that the galactose ligand principally targeted the liver while the chitosan functionalities led to excretion through the urinary system. Conclusion: Bioconjugation with a specific ligand endows some degree of targetability to an administered molecule or drug, as in the case of galactose for hepatocyte in vivo, and evaluating said targetabililty is a clear example of the great benefit proffered by nuclear imaging.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.1-7
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• 2005

Tidal flats have been regarded to carry out transformation and removal of land-derived organic matter, and this purifying capability of organic matter by tidal flats is one of very important reasons for their conservation. However, integral biogeochemical studies on production and decomposition of organic matter by benthic microbes in tidal flats have been absent in Korea, although the information is indispensable to quantification of the purifying capability. Our major goals in this multidisciplinary research were to understand major biogeochemical processes and rates mediated by diverse groups of microbes dominating material cycles in the tidal flats, and to assess the contribution of benthic microbes to removal of organic matter and nutrients in the tidal flats. Our study sites were Ganghwa and Incheon north-port tidal flats that had been regarded as naturally well reserved and organically polluted, respectively. Our research group measured over 3 years primary production, biomass and community structure of primary producers, abundance and production of bacteria, enzyme activities, distribution of protozoa and protozoan grazing rates, rates of denitrification and sulfate reduction, early sediment diagenesis, primary production and respiration based on oxygen microelectrode. We analyzed major features of each biogeochemical process and their interactions. The results are compiled in the following articles in this special issue: An (2005), Hwang and Cho (2005), Mok et at. (2005), Na and Lee (2005), Yang et at. (2005), and Yoo and Choi (2005).

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.632-637
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• 1996

Effects of refrigeration temperature and its fluctuation range on the growth of psychrotrophic microorganisms and the quality of refrigerated foods such as apple, fish and oyster were evaluated to find optimum storage conditions for a domestic refrigerator. Refrigeration temperature was $2^{\circ}C$ or $4^{\circ}C$, and fluctuation ranges were varied: ${\pm}0.3,\;{\pm}1.0,\;{\pm}1.2,\;or\;{\pm}4.0^{\circ}C$. Changes in hardness of apples stored at $2{\pm}0.3^{\circ}C$ were much slower than those of apples stored at $4{\pm}1.2^{\circ}C$. Freshness of fish and oyster also lasted much longer at low temperature such as $2{\pm}0.3^{\circ}C$. The growth of Listeria monocytogenes inoculated on sliced ham was inhibited for 1 month at $2{\pm}0.3^{\circ}C$, but the cells at $4{\pm}1.2^{\circ}C$ began to grows as time elapsed. Therefore, it was expected that shelf-life of certain food stored in a domestic refrigerator could be extended by lowering temperature to $2^{\circ}C$ and by reducing fluctuation range of refrigerator.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.2
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• pp.133-139
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• 2004

Objective: To investigate the association of FSH receptor (FSHR) polymorphism at position 680 with outcomes of controlled ovarian hyper-stimulation for IVF-ET in Korean women. Design: Genetic polymorphism analysis. Materials and Methods: The FSHR polymorphism was analyzed by PCR-RFLP in 172 ovulatory women below the age of 40 year. Patients with polycystic ovary syndrome, endometriosis, or previous history of ovarian surgery were excluded. Results: Genotype distribution was 41.9% for the Asn/Asn, 47.7% for the Asn/Ser, and 10.5% for the Ser/Ser FSHR genotype group. There was no difference in age of subjects and infertility diagnosis between genotype groups. When the patients were grouped according to their FSHR genotype, the basal levels of FSH (day 3) were significantly different among the three groups ($6.0{\pm}0.3\;IU/L$ (mean $\pm$ SEM), $5.8{\pm}0.3\;IU/L$, and $8.6{\pm}1.2\;IU/L$ for the Asn/Asn, Asn/Ser, and Ser/Ser groups, respectively, p=0.002). The Ser/Ser group showed a higher total doses of gonadotropins required to achieve ovulation induction, and a lower serum estradiol levels at the time of hCG administration compared with other two groups, but the differences were of no statistical significance. The numbers of oocytes retrieved were significantly different among the three groups ($8.6{\pm}0.8$, $9.9{\pm}0.6$, and $6.3{\pm}0.9$, for the Asn/Asn, Asn/Ser, and Ser/Ser groups, respectively, p=0.049). Clinical pregnancy rates were 42.4%, 25.9%, and 29.4% for the Asn/Asn, Asn/Ser, and Ser/Ser groups, respectively. Conclusion: Homozygous Ser/Ser genotype of FSHR polymorphism at position 680 was associated with decreased ovarian response to gonadotropin stimulation for IVF-ET.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.1
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• pp.1-12
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• 2002

Objective: In order to acquire the technique for the establishment of human embryonic stem cells (ESe) derived from the human frozen-thawed embryos produced in IVF-ET program, this study was performed to establish mouse ESC derived from the in vitro fertilized embryos. Materials and Methods: After Fl hybrid (C57BL female $\times$ CBA mael) female mice were superovulated with PMSG and hCG treatment, their oocytes were retrieved and inseminated, and the fertilized embryos were cultured for 96-120 hours until the expected stages of blastocysts were obtained. To isolate the inner cell mass (ICM), either the blastocysts were treated with immunosurgery, or the whole embryos were cultured for 4 days. Isolated ICMs were then cultured onto STO feeder cell layer, and the resultant ICM colonies were subcultured with trypsin-EDTA treatment. During the subculture process, ESC-like cell colonies were observed with phase contrast microscopy. To identify ESC in the subcultured ESC-like cell colonies, alkaline phosphatase activity and Oct-4 (octamer-binding transcription factor-4) expression were examined by immunohistochemistry and RT-PCR, respectively. To examine the spontaneous differentiation, ESC-like cell colonies were cultured without STO feeder cell layer and leukemia inhibitory factor (LIF). Results: Seven ESC-like cell lines were established from ICMs isolated from the in vitro fertilized embryos. According to the developmental stage, the growth of ICMs isolated from the expanded blastocysts was significantly better than that of ICMs isolated from the hatched blastocysts (80.3% vs. 58.7%, p<0.05). ESC-like cell colonies were only obtained from ICMs of expanded blastocysts. However, the ICMs isolated from the embryos treated with immunosurgery were poorly grown and frequently differentiated during the culture process. The established ESC-like cell colonies were positively stained with alkaline phosphatase and expressed Oct-4, and their morphology resembled that observed in the previously reported mouse ESC. In addition, following the extended in vitro culture process, they maintained their expression of cell surface markers characteristic of the pluripotent stem cells such as alkaline phosphatase and Oct-4. When cultured without STO feeder cell layer and LIF, they were spontaneously differentiated into the various types of cells. Conclusion: The findings of this study suggest that the establishment of mouse ESC can be successfully derived from the in vitro fertilized embryos. The established ESC-like cells expressed the cell surface markers characteristic of the pluripotent stem cells and spontaneously differentiated into the various types of cells.