• The Journal of Korean Academy of Prosthodontics
• /
• v.50 no.4
• /
• pp.285-291
• /
• 2012

Purpose: This study was conducted to identify the surface characteristics of titanium discs coated with MS275/PLGA by electrospray and which is effective to mesenchymal stem cell proliferation. Materials and methods: We used anodized surface coated with PLGA as a control group and anodized surface coated with MS275 $0.5{\mu}M$, $1{\mu}M$, $1.5{\mu}M$ as test groups. To examine that the coating particles are nanometer sized, FE-SEM was used and AFM was utilized to determine the difference of coating surface roughness. We checked the mesenchymal stem cell proliferation by using MTT assay on $1^{st}$, $4^{th}$, $7^{th}$ days. Results: There was no significant difference between control groups and test groups in AFM results (P>.05). In MTT assay results, mesenchymal stem cell proliferation was increased with time, at $7^{th}$ day, cell viability on discs coated with $1.5{\mu}M$ MS275 was significantly higher than control group (P<.05). As SEM showed, the number of cells on all discs was increased and the morphology of cell attachment was also wider and closer with time. Conclusion: Titanium surface coated with MS275/PLGA showed significantly higher cell proliferation and the more density of MS275 was dispersed on titanium discs, the faster cells grew.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.2
• /
• pp.210-220
• /
• 1996

Background : Neutrophils or monocytes separated in vitro by the adherence to plastic surface are known to be activated by surface adherence itself and subsequent experimental data might be altered by surface adherence. In the process of surface adherence, adhesion molecules have a clear role in intracellular signal pathway of cellular activation. Human alveolar macrophages(HAM) are frequently purified by the adherence procedure after bronchoalveolar lavage. But the experimental data of many reports about alveolar macrophages have ignored the possibility of adhesion-induced cellular activation. Method : Bronchoalveolar lavage was performed in the person whose lung of either side was confirmed to be normal by chest CT. With the measurement of hydrogen peroxide release from adherent HAM to plastic surface and non-adherent HAM with or without additional stimulation of phorbol myristate acetate(PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP), we observed the effect of the adherence to plastic surface. We also evaluated the effect of various biological surfaces on adhesion-induced activation of HAM. Then, to define the intracellular pathway of signal transduction, pretreatment with cycloheximide, pertussis toxin and anti-CD11/CD18 monoclonal antibody was done and we measured hydrogen peroxide in the culture supernatant of HAM. Results : 1) The adherence itself to plastic surface directly stimulated hydrogen peroxide release from human alveolar macrophages and chemical stimuli such as phorbol myristate acetate(PMA) or N-formyl-methionyl-leucyl-phenylalanine(fMLP) colud not increase hydrogen peroxide release in these adherent macrophages which is already activated. 2) PMA activated human alveolar macrophages irrespective of the state of adhesion. However, fMLP stimulated the release of hydrogen peroxide from the adherent macrophages, but not from the non-adherent macrophages. 3) HAM adherent to A549 cell(type II alveolar epithelium-like human cell line) monolayer released more hydrogen peroxide in response to both PMA and fMLP. This adherence-dependent effect of fMLP was blocked by pretreatment of macrophages with cycloheximide, pertussis toxin and anti-CD18 monoclonal antibody, Conclusion : These results suggest that the stimulatory effect of PMA and fMLP can not be found in adherent macrophage because of the activation of human alveolar macrophage by the adherence to plastic surface and the cells adhered to biologic surface such as alveolar epithelial cells are appropriately responsive to these stimuli. It is also likely that the effect of fMLP on the adherent macrophage requires new protein synthesis via G protein pathway and is dependent on the adhesion between alveolar macrophages and alveolar epithelial cells by virtue of CD11/CD18 adhesion molecules.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.1
• /
• pp.43-52
• /
• 2000

Deodorization characteristics and removal rate of sulfur-containing odor have been investigated in the soil filter reactors packed with montmorillonites (Mont.), rice hulls(Rh.), and thickening-activated sludge(Ts.). And variation of pH and $SO_4{^{2-}}$ with the removal of malodorous sulfur compounds have been investigated together. As compared removal rate of montmorillonites between wet and dry condition for sulfur compounds through batch test, it showed that wet condition was better than dry one; removal ratio, as wet/dry, was $H_2S$ of 1.2 and $CH_3SH$ of 1.9, and decrease of pH and increase of $SO_4{^{2-}}$ concentration in the wet condition also showed to be larger than in dry condition. In continuous test for biological deodorization experiment, removal rate of sulfur compounds in reactor packed with Mont., Rh. and Ts, was more than 98 %, and the variation of static pressure was maintained stably under condition of SV $150h^{-1}$, LV 4.2 mm/sec and SV $200h^{-1}$, LV 5.6 mm/sec, and in reactor packed with Mont. and Rh., $H_2S$ was 76.4 % to 87.2 % and $CH_3SH$ was 87.8 % to 93.3 % under the same condition. From above results, it ascertained that it can obtain the high deodorization efficiency by inoculating thickening-activated sludge in soil filter using montmorillonites.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.6
• /
• pp.702-708
• /
• 2002

Although Umboniunm thomasi is one of marine mollusc (Archaeogastropoda: Trochidae) inhabiting the sands in the intertidal zone of the west coast of Korea, aspects of its reproductive biology are still not too well known. Reproductive cycle, gametogenesis, and first sexual maturity of U. thomasi collected at the west coast of Buan-gun, Jeollabuk-do, Korea were investigated monthly from January to December 1999. U. thomasi was dioecious, and an oviparous. The gonad was placed in the rear of the flesh part in the spiral shell. The external colors of the ripe ovary and testis appeared to be green and milk-white or yellowish white, respectively. Meat weigh rate peaked in July ($37.5\%$). And then the value sharply decreased in September ($28.3\%$), thereafter, gradually increased in November ($31.7\%$). Fully ripe oocytes were approximately 100$\~$110 $/mu$m in diameter, and their cytoplasm contained a great number of yolk Branules. Based on the monthly changes of the Bonadal development, gametogenesis, and meat weight rate, the reproductive cycle of U. thomasi could be devided into five successive stages: early active (November to April), late active (February to May), ripe (April to August), spawning (July to October), and recovery (September to February). Gonadal development and spawning were closely related to the seawater temperature, the main spawning occurred in September when the temperature reached above 24.2$^{\circ}C$. Individuals of 4.4 mm and less in shell height could not take part in reproduction in both sexes. Percentages of first sexual maturity of female and male shells ranging from 5.5 to 6.4 mm were $55.0\%$ and $61.9\%$, respectively, and $100\%$ of those over 7.5 mm in shell heights in both sexes participated in the reproduction.

• Clean Technology
• /
• v.28 no.4
• /
• pp.269-277
• /
• 2022

With the recent development of the biological enzymatic reaction industry, lactic acid (LA) can be mass-produced from biomass sources. In particular, a catalytic process that converts LA into acrylic acid (AA) is receiving much attention because AA is used widely in the petrochemical industry as a monomer for superabsorbent polymers (SAP) and as an adhesive for displays. In the LA conversion process, NaY zeolites have been previously shown to be a high-activity catalyst, which improves AA selectivity and long-term stability. However, NaY zeolites suffer from fast deactivation due to severe coking. Therefore, the aim of this study is to modify the acid-base properties of the NaY zeolite to address this shortcoming. First, base promoters, Ca ions, were introduced to the NaY zeolites to tune their acidity and basicity via ion exchange (IE) and incipient wetness impregnation (IWI). The IWI method showed superior catalyst selectivity and stability compared to the IE method, maintaining a high AA yield of approximately 40% during the 16 h reaction. Based on the NH₃- and CO₂-TPD results, the calcium salts that impregnated into the NaY zeolites were proposed to exit as an oxide form mainly at the exterior surface of NaY and act as additional base sites to promote the dehydration of LA to AA. The NaY zeolites were further treated with KOH before calcium impregnation to reduce the total acidity and improve the dispersion of calcium through the mesopores formed by KOH-induced desilication. However, this KOH treatment did not lead to enhanced AA selectivity. Finally, calcium loading was increased from 1wt% to 5wt% to maximize the amount of base sites. The increased basicity improved the AA selectivity substantially to 65% at 100% conversion while maintaining high activity during a 24 h reaction. Our results suggest that controlling the basicity of the catalyst is key to obtaining high AA selectivity and high catalyst stability.

• Development and Reproduction
• /
• v.9 no.2
• /
• pp.95-103
• /
• 2005

Reproductive cycle, gonadosomatic index(GSI), egg diameter composition, first sexual maturity, sexually matured length(50% of first sexual maturity), and sex ratio of Amusium japonicum japonicum, were investigated by histological observations and morphometric data. Samples were collected monthly from the subtidal zone of Sogwipo, Jejudo, Korea, for two years. The sun and moon scallop Amusium japonicum japonicum is dioecious. Monthly variation in the GSI showed similar patterns with the reproductive cycle. Ripe oocytes were about $70{\sim}90\;{\mu}m$ in diameter and had thick egg membranes. The spawning period was from November to January, and the main spawning occurred between November and December when the seawater temperature was relatively low. From monthly changes in egg diameter composition, the spawning period was once a year, although the number of spawning frequencies is assumed to occur more than twice during the spawning season. The reproductive cycle of this species could be divided into five successive stages: early active stage(April to June), late active stage(June to September), ripe stage(October to November), spawning stage(November to January), and spent/resting stage(February to April). First sexual maturities in female and male scallops ranging from 85.1 to 90.0mm in shell length were over 50% and they were 100% for scallops over 90.0mm in shell length. In this population, sexually matured shell lengths(50% of rate of group maturity) in females and males were 86.96 and 86.59mm, respectively. The female to male sex ratio among individuals over 85.1mm in shell length was not significantly different from 1:1($X^2=0.18$, p>0.05). No evidence of hermaphrodite was found in histological sections of any scallop examined.

• Korean Journal of Microbiology
• /
• v.52 no.3
• /
• pp.278-285
• /
• 2016

The bifunctional PheA protein, having chorismate mutase and prephenate dehydratase (CMPD) activities, is one of the key regulatory enzymes in the aromatic amino acid biosynthesis in Escherichia coli, and is negatively regulated by an end-product, phenyalanine. Therefore, PheA protein has been thought as useful for protein engineering to utilize mass production of essential amino acid phenylalanine. To obtain feedback resistant PheA protein against phenylalanine, we mutated by using random mutagenesis, extensively screened, and obtained $pheA^{FBR}$ gene encoding a feedback resistant PheA protein. The mutant PheA protein contains substitution of Leu to Phe at the position of 118, displaying that higher affinity (about $290{\mu}M$) for prephenate in comparison with that (about $850{\mu}M$) of wild type PheA protein. Kinetic analysis showed that the saturation curve of $PheA^{FBR}$ against phenyalanine is hyperbolic rather than that of $PheA^{WT}$, which is sigmoidal, indicating that the L118F mutant enzyme has no cooperative effects in prephenate binding in the presence of phenylalanine. In vitro enzymatic assay showed that the mutant protein exhibited increased activity by above 3.5 folds compared to the wild type enzyme. Moreover, L118F mutant protein appeared insensitive to feedback inhibition with keeping 40% of enzymatic activity even in the presence of 10 mM phenylalanine at which the activity of wild type $PheA^{WT}$ was not observed. The substitution of Leu to Phe in CMPD may induce significant conformational change for this enzyme to acquire feedback resistance to end-product of the pathway by modulating kinetic properties.

• Korean Journal of Food Science and Technology
• /
• v.8 no.2
• /
• pp.95-106
• /
• 1976

In order to investigate chemical components and mineral of ginseng cultivated in Korea and to establish an appropriate extraction method, the present work was carried out with Raw ginseng(SC), White ginseng(SB) and Ginseng tail(SA). The results determined could be summarized as follows : 1. Among the proximate components, moisture content of SC, SB and SA were 66.37%, 12.61% and 12.20% respectively. The content of crude ash in SA was the highest value of three kinds of ginseng root: SA 6.04%, SB 3.52% and SC 1.56%. The crude protein of Dried ginseng root(SA and SB) was about 12-14%, which was more than two times compared with that of SC(6.30%) The content of pure protein seemed to be in similar tendency with that of crude protein in three kinds of ginseng root: 2.26% in SC, 5.94% in SB and 5.76% in SA. There was no significant difference in the content of fat among the kinds of ginseng root. $(1.1{\sim}2.5%)$ 2. The highest Ginseng extract was obtained by use of Continuous extractor which is a modified Soxhlet apparatus for 60 hours extraction with 60-80% ethanol. 3. Ginseng and the above-mentioned ginseng extract (Ginseng tail extract: SAE, White Ginseng extract : SBE, Raw Ginseng extract: SCE) were analyzed by volumetric method for the determination of Chlorine and Calcium, by colorimetric method for that of Iron and Phosphorus, by Atomic Absorption Spectrophotometer for that of Zinc, Copper and Manganese. The results were as follows : 1. The content of phosphorus in SA, SB and SC were 1.818%, 1.362%, 0.713% respectively and phosphorus content in three kinds of extract were in low level (SAE: 0.03%, SBE: 0.063%, SCE: 0.036%) 2. In the Calcium content, SA, SB and SC were 0.147%, 0.238%, 0.126% and the Calcium contents of Ginseng extracts were 0.023%, 0.011% and 0.016%. The extraction ratio of Calcium from SA was the highest value (15.6%), while that in the case of SB was 4.6%. 3. The Chlorine content of SA was 0.11%, this was slightly higher than others(SB: 0.07%, SC: 0.09%) and extraction ratio of SA and SB were 36.4%, 67.1% while that of SC was 84.4%. 4. The Iron content of SA, SB and SC were 125ppm, 32.5ppm and 20ppm but extraction ratio was extremely low (SAE: 1.33%, SBE: 0.83%, SCE: 1.08%), 5. The Manganese content of SA, SB and SC were 62.5ppm, 25.0ppm and 5.0ppm respectively but the Manganese content of extract could not determined, Copper content of SA, SB and SC were 15.0ppm, 20.0ppm and those of extract were 7.5ppm, 6.5ppm, 4.5ppm while those of extraction ratio were 50%, 32.5% and 90% respectively, Zinc was abundant in Ginseng compared with other herbs, (SA: 45.5ppm, SB: 27.5ppm and SC: 5.5ppm) and the extracted amount were 4.5ppm, 1.25ppm 1.50ppm respectively.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.10
• /
• pp.1448-1453
• /
• 2012

Fried fish pastes containing different size and amounts of red ginseng powder (RGP) were manufactured, and their physico-chemical and biological properties, including color changes, preservation, weight loss after heating, lipid oxidation, and total colony count were analyzed to improve fish paste quality. Sensory evaluation of fish pastes containing RGP was carried out, and the results showed that 1% and 850 ${\mu}m$ sized RGP additives were most preferred. In the color change test, decreased $L^*$ (lightness), increased $a^*$ (redness), and increased $b^*$ (yellowness) values were observed, which was similar to other additive-containing commercial fish pastes. In the physical properties test, hardness and chewiness significantly increased in the 90 ${\mu}m$ sized RGP group. Weight loss of fish pastes containing RGP after heating was attenuated compared to commercial fish pastes. Fish paste containing RGP showed an inhibitory effect on lipid oxidation. Especially, the 10 ${\mu}m$ sized RGP group showed the most significant inhibitory effect on lipid oxidation and reduced total microbes during storage. Therefore, 1% addition of RGP can give rise to high quality fish pastes through improvement of sensory evaluation and physico-chemical properties. Moreover, functionally and physiologically improved fish pastes can be produced by adding different amounts of RGP.

• The Korean Journal of Nuclear Medicine
• /
• v.38 no.2
• /
• pp.180-189
• /
• 2004

Although the outcome of cancer patients after cytotoxic chemotherapy is related diverse mechanisms, multidrug resistance (MDR) for chemotherapeutic drugs due to cellular P-glycoprotein (Pgp) or multidrug-resistance associated protein (MRP) is most important factor in the chemotherapy failure to cancer. A large number of pharmacologic compounds, including verapamil, quinidine, tamoxifen, cyclosporin A and quinolone derivatives have been reported to overcome MDR. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transporter. $^{99m}Tc$-MIBI and other $^{99m}Tc$-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of PgP-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with $^{11}C$ have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and $N-[^{11}C]acetyl-leukotriene$ E4 provides an opportunity to study MRP function non-invasively in vivo. SPECT and PET pharmaceuticals have successfully used to evaluate pharmacologic effects of MDR modulators. Imaging of MDR and reversal of MDR with bioluminescence in a living animal is also evaluated for future clinical trial. We have described recent advances in molecular imaging of MDR and reviewed recent publications regarding feasibility of SPECT and PET imaging to study the functionality of MDR transporters in vivo.