• KSBB Journal
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• v.21 no.3
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• pp.171-174
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• 2006

To clarify the usefulness of fluorescent diagnosis for cancer, We investigated the optimal method of administrating 5-aminolevulinic acid(5-ALA) by analyzing fluorescence signal of Protoporphyrin IX(PpIX) in the cultured normal and cancer cells. 5-ALA was injected as a photosensitizer to the cervico-uterine cancer cell line(HeLa) and in normal liver cells(Chang). Chang and HeLa cells were incubated with various concentrations of 5-ALA($0-800{\mu}g/ml$). The accumulation of PpIX induced by 5-ALA was in HeLa and Chang cells. The cell viability was measured by MTT assay. The optimal concentration of ALA that induced maximum levels of PpIX was $50{\mu}g/ml$ in HeLa cell cultured for 24 hours after 5-ALA injection. Fluorescence of PpIX in HeLa cell was excited at a wavelength(${\lambda}$=410 nm) and showed an emission spectrum at 602.3 nm, 659.9 nm which could be related to the PpIX generation induced by the applied 5-ALA. The experimental results showed that fluorescence signal of PpIX was proportional to the concentration of 5-ALA in cancer cells, but measured with low concentration in normal cells.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.430-436
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• 2010

The objective of the present studies was to develop and validate a system for isolation, purification and extended culture of pigment-producing cells in alpaca skin (melanocytes) responsible for coat color and to determine the effect of alpha melanocyte stimulating hormone treatment on mRNA expression for the melanocortin 1 receptor, a key gene involved in coat color regulation in other species. Skin punch biopsies were harvested from the dorsal region of 1-3 yr old alpacas and three different enzyme digestion methods were evaluated for effects on yield of viable cells and attachment in vitro. Greatest cell yields and attachment were obtained following dispersion with dispase II relative to trypsin and trypsin-EDTA treatment. Culture of cells in medium supplemented with basic fibroblast growth factor, bovine pituitary extract, hydrocortisone, insulin, 12-O-tetradecanolphorbol-13-acetate and cholera toxin yielded highly pure populations of melanocytes by passage 3 as confirmed by detection of tyrosinase activity and immunocytochemical localization of melanocyte markers including tyrosinase, S-100 and micropthalmia-associated transcription factor. Abundance of mRNA for tyrosinase, a key enzyme in melanocyte pigment production, was maintained through 10 passages showing preservation of melanocyte phenotypic characteristics with extended culture. To determine hormonal responsiveness of cultured melanocytes and investigate regulation of melanocortin 1 receptor expression, cultured melanocytes were treated with increasing concentrations of ${\alpha}$-melanocyte stimulating hormone. Treatment with ${\alpha}$-melanocyte stimulating hormone increased melanocortin receptor 1 mRNA in a dose dependent fashion. The results demonstrated culture of pure populations of alpaca melanocytes to 10 passages and illustrate the potential utility of such cells for studies of intrinsic and extrinsic regulation of genes controlling pigmentation and coat color in fiber-producing species.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.342-350
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• 2008

This study was carried out to investigate the suitability of the pubertal assay and the enhanced TG 407 as methods for detection of endocrine-mediated effects. Thyroid function was also considered. Male and female Sprague-Dawley rats were gavaged daily with 0, 25, 50, 100 mg/kg metribuzin in corn oil during 30 days. The effects of metribuzin on thyroid gland, the genital organs and thyroid hormone were measured in male and female rats. Dose of metribuzin 50 mg/kg/day increased relative weight of testis, prostate, and seminal vesicle in male rats but relative weight of thyroid gland was not significantly different from control group. Dose of metribuzin 25 mg/kg/day decreased relative weight of thyroid gland in female rats. Another purpose of this study was to investigate the effects of endocrine-disruptors as like thyroid hormone in vitro. Luciferase activity was measured to detect reaction of test chemicals and thyroid hormone response elements in HeLaTRE cell. Dose of metribuzin from 1 to 1,000 nM increased to 106-122% of luciferase activity.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.2 s.52
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• pp.152-158
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• 2004

Among short-term in vitro genotoxicity assays, micronucleus assays are rapid, inexpensive, and less labor-intensive system. We have undertaken a comparative study of sensitivity of cigarette smoke condensate(CSC) by general micronucleus(MN) assay and cytokinesis-block micronucleus(CBMN) assay. In this study, V79 Chinese hamster cells were employed to evaluate and compare the genotoxicity of CSC of Kentucky Reference Cigarette 2R4F by 2 kinds of in vitro MN assay methods. To determine the optimum concentration of cytochalasin B(CYB) to obtain the maximal number of binucleated cells for CBMN assay, triplicate cultures of growing cells were treated with CYB for 15 h. CYB treatments caused a concentration-dependent increase in cytotoxicity($1\~4{\mu}g/mL$) and proportion($0.25\~1\;{\mu}g/mL$) of binucleated cells. These data suggested that 1 ug/mL of CYB is as an optimum dose for CBMN assay in binucleated V79 cells. Short treatment(4 h) of CSC induced a micronucleated cells with a concentration-dependent response in the presence or absence of CYB, but CSC-induced MNs were weakened when S9 was present. Long treatments(19 h) of CSC also induced a significant increase MN formation with a concentration-dependent response. At a concentration of 75 ${mu}g/mL$, the MN cell frequencies of general MN assay and CBMN assay were $6.5\%\;and\;11.7\%$, respectively. Linear regression analysis revealed a good correlation in CBMN assay between a concentration of CSC and MN cell frequency. All these data indicated that CBMN assay is more sensitive to the induction CSC-induced MN than general MN assay.

• Development and Reproduction
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• v.13 no.4
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• pp.217-226
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• 2009

Effects of sera from several fish species on monolayer formation, viability and functions of catfish hepatocytes were investigated to establish a primary hepatocyte culture system for screening endocrine disruptors. Hepatocytes of Korean catfish (Silurus asotus) were attached and formed monolayer using the media supplemented with their own serum or sera from eel and tilapia, but not with fetal bovine serum (FBS). The amount of fish sera (0.5~3%) for monolayer culture of the catfish hepatocytes was less than 1/10 of FBS (5~20%) that is commonly used for primary culture of hepatocytes of other species. The results indicate that FBS can be replaced with sera from some fish species and the fish sera are more effective than FBS in maintaining the shape and functions of the hepatocytes. The primary culture of catfish hepatocytes was maintained monolayer with fish sera for at least 10 days, which makes possible to be used for screening the activities of endocrine disruptors. In conclusion, the primary culture system of hepatocytes with fish sera in the present study could be a useful tool for screening and studying endocrine disruptors.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.1-10
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• 2000

Fungicide resistance study in Korea is still in its infancy, and most of those resistance studies are largely limited to newness of the detected resistant strains. In future, detection of fungicide-resistant strains has to be based on sensitivity distribution of pathogen populations to certain fungicides, and standard levels of certain fungicides for resistance should be determined under the basis of this data. Most of the early research on fungicide resistance in Korea has overlooked this point, and resulted in inconsistency and confusion for monitoring sensitivity shift of pathogen population among individual researchers. Fungicide resistance detected in vitro tests has to be documented in field trials by examining control efficacy against resistant and wild-type pathogen populations. Resistance detection in wife has to be correlated with lower activity in practice. Using this process, fungicide resistance will have a practical meaning. Fitness evaluation of resistant strains for survival is, in particular, of importance to determine the future stability of the resistance in the pathogen population. In fields, sensitivity change of pathogen populations should be carefully monitored with and without fungicide selection pressures to establish long-term management strategies against fungicide resistance. It is becoming an urgent task to provide information through research for designing and implementing successful counter-measures against fungicide resistance problems in Korea.

• Archives of Pharmacal Research
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• v.19 no.4
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• pp.251-257
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• 1996

The detection of many synthetic chemicals used in industry that may pose a genetic hazard in our environment is subject of great concern at present. In this respect, the genetic toxicity of fenpropathrin ((RS)-.alpha.-cyano-3-phenoxybenzyl-2,2,3,3-tetramethyl cyclopropane carboxylate, CAS No.:39514-41-8), a pyrethroid insecticide, was evaluated in bacterial gene mutation system, chromosome aberration in mammalian cell system and in vivo micronucleus assay with rodents. In bacterial gene mutation assay, no mutagenicity of fenpropathrin (62-$5000\mug/plate$) was observed in Salmonella typhimurium TA 98, 100, 1535 and 1537 both in the absence and in the presence of S-9 metabolic activaton system. In mammalian cell system using chinese hamster lung fibroblast, no clastogenicity of fenpropathrin was also observed both in the absence and in the presence of metabolic activation system in the concentration range of $7-28\mug/ml$. And also, in vivo micronucleus assay using mouse bone marrow cells, fenpropathrin also revealed no mutagenic potential in the dose range of 27-105 mg/kg body weight of fenpropathrin (i.p.). Consequently, no mutagenic potential of fenpropathrin was observed in vitro bacterial, mammalian mutagenicity systems and in vivo micronucleus assay in the dose ranges used in this experiment.

• Imaging Science in Dentistry
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• v.43 no.3
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• pp.171-177
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• 2013

Purpose: The purpose of this study was to compare the efficacy of two imaging modes in a cone beam computed tomography (CBCT) system in detecting root fracture in endodontically-treated teeth with fiber posts or screw posts by selecting two fields of view. Materials and Methods: In this study, 78 endodontically-treated single canal premolars were included. A post space was created in all of them. Then the teeth were randomly set in one of 6 artificial dental arches. In 39 of the 78 teeth set in the 6 dental arches, a root fracture was intentionally created. Next, a fiber post and a screw post were cemented into 26 teeth having equal the root fractures. High resolution (HiRes) and standard zoom images were provided by a CBCT device. Upon considering the reconstructed images, two observers in agreement with each other confirmed the presence or absence of root fracture. A McNemar test was used for comparing the results of the two modes. Results: The frequency of making a correct diagnosis using the HiRes zoom imaging mode was 71.8% and in standard zoom was 59%. The overall sensitivity and specificity in diagnosing root fracture in the HiRes mode were 71.79% and 46.15% and in the standard zoom modes were 58.97% and 33.33%, respectively. Conclusion: There were no significant differences between the diagnostic values of the two imaging modes used in the diagnosis of root fracture or in the presence of root canal restorations. In both modes, the most true-positive results were reported in the post space group.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.253-266
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• 1995

Recently, available interests concerning the biologic significance of the extracellular matrix and proliferating cells associated with periodontal disease has been increased. The distribution or expression of cellular proliferation by PCNA, macrophage detection by ${\alpha}$-l-antichymotrypsin, fibronectin playing a important role in host defence mechanisms indirectly, and transglutaminase that cross linked to fibronectin and stimulate fibrin stabilization were studied in inflammed and healthy gingiva. The excised tissue samples were fixed neutral formalin for 24 hours, embedded with paraffin, sectioned at 4-61lffi in thickness, and immunohistochemically processed by LSAB method. The positive reaction to PCNA was localized in the suprabasal and basal layer of inflammed gingiva and an increasing reactivity was observed than healthy gingiva. ${\alpha}$-I-antichymotrypsin positive cells were localized in the basal layer of inflammed gingiva, and there was no or rare positive cells in healthy gingiva. The positive reaction to fibronectin in inflammed gingiva was more than healthy gingiva,"and shown in the connective tissue subjacent to basement membrane of epithelium and in the periphery of the collagen fiber bundles. The positive cells by transglutaminase in inflammed gingiva were noted in suprabasal, spinous, and keratin layer of epithelium, and slightly increased in the capillaries of connective tissues. But the results of this study demonstrated in vitro reaction. Therefore, the role of PCNA,${\alpha}$-l-antichyrnotrypsin, transglutaminase, fibronectin and coefficient with other growth factor and extracellular matrix were further investigated in vivo.

• Nutrition Research and Practice
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• v.7 no.4
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• pp.249-255
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• 2013

In this study, the protective effects of EGCG on L-3,4-dihydroxyphenylalanine (L-DOPA)-induced oxidative cell death in catecholaminergic PC12 cells, the in vitro model of Parkinson's disease, were investigated. Treatment with L-DOPA at concentrations higher than $150{\mu}M$ caused cytotoxicity in PC12 cells, as determined using the 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry detection. The apoptotic ratio was similar in cells treated with $100{\mu}M$ EGCG plus $150{\mu}M$ L-DOPA (5.02%) and the control (0.96%) (P > 0.05), and was lower than that of cells treated with L-DOPA only (32.24%, P < 0.05). The generation level of ROS (% of control) in cells treated with EGCG plus L-DOPA was lower than that in cells treated with L-DOPA only (123.90% vs 272.32%, P < 0.05). The optical density in production of TBARS in cells treated with L-DOPA only was higher than that in the control ($0.27{\pm}0.05$ vs $0.08{\pm}0.04$, P < 0.05), and in cells treated with EGCG only ($0.14{\pm}0.02$, P < 0.05), and EGCG plus L-DOPA ($0.13{\pm}0.02$, P < 0.05). The intracellular level of GSH in cells treated with EGCG plus L-DOPA was higher than that in cells treated with L-DOPA only ($233.25{\pm}16.44$ vs $119.23{\pm}10.25$, P < 0.05). These results suggest that EGCG protects against L-DOPA-induced oxidative apoptosis in PC12 cells, and might be a potent neuroprotective agent.