• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.108-109
• /
• 2013

Mitochondria play key roles in the production of cell's energy. Their dominant function is the synthesis of adenosine 5'-triphosphate (ATP) from adenosine diphosphate (ADP) and phosphate (Pi) through the oxidative phosphorylation. Evaluation of drug-induced mitochondrial toxicity has become increasingly important since mitochondrial dysfunction has recently been implicated in numerous diseases including cancer and diabetes mellitus. Mitochondrial functions have been monitored via oxygen consumption, mitochondrial membrane potential, and more importantly via ATP synthesis since ATP synthesis is the most essential function of mitochondria. Various analytical methods have been employed to investigate ATP synthesis in mitochondria, including high performance liquid chromatography (HPLC), bioluminescence technique, and pH measurement. However, most of these methods are based on destructive analysis or indirect monitoring through the enzymatic reaction. Infrared absorption spectroscopy (IRAS) is one of the useful techniques for real-time, label-free, and direct monitoring of biological reactions [1,2]. However, the strong water absorption requires very short path length in the order of several micrometers. Transmission measurements with thin path length are not suitable for mitochondrial assays because solution handlings necessary for evaluating mitochondrial toxicity, such as rapid mixing of drugs and oxygen supply, are difficult in such a narrow space. On the other hand, IRAS in the multiple internal reflection (MIR) geometry provides an ideal optical configuration to combine solution handling and aqueous-phase measurement. We have recently reportedon a real-time monitoring of drug-induced necrotic and apoptotic cell death using MIR-IRAS [3,4]. Clear discrimination between viable and damaged cells has been demonstrated, showing a promise as a label-free and real-time detection for cell-based assays. In the present study, we have applied our MIR-IRAS system to mitochondria-based assays by monitoring ATP synthesis in isolated mitochondria from rat livers. Mitochondrial ATP synthesis and hydrolysis were in situ monitored with MIR-IRAS, while dissolved oxygen level and solution pH were simultaneously monitored with O2 and pH electrodes, respectively. It is demonstrated that ATP synthesis and hydrolysis can be monitored by the IR spectral changes in phosphate groups in adenine nucleotides and MIR-IRAS is useful for evaluating time-dependent drug effects of mitochondrial toxicants.

• Applied Biological Chemistry
• /
• v.29 no.1
• /
• pp.90-95
• /
• 1986

A comparative study of chemical characteristics, efficacy and relative merits of extruded and coated granules, containing fungicide and insecticide, was conducted under laboratory and field conditions. Probenzole (3-allyloxy-1,2-benzisothiazole 1,1-dioxide) and carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methyl carbamate) were chosen as toxicants for rice blast(Pyricularia oryzae) and brown planthopper (Nilaparvata lugens) control, respectively. Stability of active ingredients in coated granule was superior to the extruded one under accelerated temperature. Active ingredient dissolution of coated one into distilled water showed slow release pattern. Pesticide residues in rice (Oryzae sativa, Chucheongbyeo) shoot applied with extruded one at the dosage of 3kg/10a retained higher levels than those with coated one on two days after application, while the residue levels were a reversed tendency on eight days after application. Efficacy on rice blast exhibited minute differences between the granules, on the other hand efficacy on brown planthopper by coated one was of higher rank than that by extruded one. Production cost of the combined pesticide granule by coating method could be cut down by 6% as compared to extrusion method.

• Journal of Environmental Health Sciences
• /
• v.34 no.4
• /
• pp.271-278
• /
• 2008

Dialkylated phthalates have been commonly used as plasticizers and a variety of applications. Phthalate diesters have been shown to be developmental and reproductive toxicants. It is very difficult to exactly estimate the dose of dialkylated phthalates taken up by the general population because of environmental contamination. Urinary metabolites of phthalates enabled to estimate internal exposure. The objective of this study was quantitative determination of phthalate metabolites by LC/MS/MS with on-line cleanup method to analyze phthalate metabolites in Korean children's urine. We employed LC/MS/MS with on-line enrichment and column-switching techniques for this biological monitoring. Metabolites determined were 4 primary metabolites; MEHP, MnBP, MiBP, MEP and 2 secondary metabolites of DEHP; 5-OH-MEHP), 5-oxo-MEHP. We analyzed children's urine from 30 boys and 30 girls. The method detection limit of phthalate metabolites were 0.03 ng/mL for MEP, 1.05 ng/mL for MBP, 0.22 ng/mL for MEHP, 0.15 ng/mL for 5-OHMEHP and 0.16 ng/mL for 5-oxo-MEHP, respectively. Switching Column LC/MS/MS was proven to be a useful tool to determine metabolites of phthalate diesters in human urine. The correlation among phthalate metabolites was very high and statistically significant, except MEP. The children's age (months) was negatively correlated to the concentration of phthalate metabolites. The geometric mean concentration of phthalate metabolites (mg/g creatinine) in children's urine were 25.5 for MEP, 130.3 for MnBP, 56.8 for MiBP, 19.5 for MEHP, 85.6 for 5-OH-MEHP and 83.1 for 5-oxo-MEHP, respectively. Levels of estimated daily intake of parent phthalate compounds (${\mu}g$/kg bw/day) were 0.8 for DEP, 5.0 for DnBP, 1.9 for DiBP and $8.9{\sim}14.2$ for DEHP, respectively. Estimated daily intake for DEP and DiBP were lower than those of other studies but the value for DEHP was higher than that of other study.

• Korean journal of food and cookery science
• /
• v.20 no.1
• /
• pp.76-80
• /
• 2004

The potato tubers of Solanum tuberosum L. contain potato glycoalkaloids (PGA), a class of naturally occurring toxicants. The primary constituents of this class of compounds in potatoes are $\alpha$-chaconine and $\alpha$-solanine. The purpose of this study was to examine the effects of various cooking methods on the PGA contents in the common Korean potato Irish Cobbler variety and those in commercially produced potato products consumed in Korea. After cooking, most potatoes showed big decreases in their PGA contents compared to the uncooked samples, with the exception of baked potatoes, which maintained 90.86％ of their PGA contents. The PGA levels in boiled and blanched potatoes were reduced by 91.68 and 84.17％, respectively. However, the levels in samples boiled in 1％ salted water were only reduced by 52.10％. Potatoes fried and sauteed in oil had their PGA contents reduced to 49.42 and 49.51％ of their original levels. The reductions in the relative PGA contents by cooking method were in the order boiling〉blanching〉boiling with 1％ NaCl〉steaming〉sauteing〉frying〉microwaving〉baking. The highest remaining PGA content of the potato products in Korea was in potato chips, at 69.57mg/100g, but made with imported potatoes.

• Korean Journal of Plant Resources
• /
• v.23 no.2
• /
• pp.165-171
• /
• 2010

Oxidative stress induced by reactive oxygen intermediates has been implicated in a variety of human diseases including neurodegenerative disorders, cancer, cardiovascular and respiratory diseases, and mode of action of environmental toxicants. Tert-butylhydroperoxide (t-BHP) is an organic lipid hydroperoxide analogue, which is commonly used as a pro-oxidant for evaluating mechanisms involving oxidative stress in cells and tissues. In this study, the underlying mechanisms involved in the protective effects of Hwabuk 94 kiwifruit (Actinidia deliciosa cv. 'Hwabuk 94'), which is cultivated in Jeju, on the t-BHP-induced cytotoxicity in PC12 cell. The pretreatment of rat pheochromocytoma cell line PC12 with Hwabuk 94 extract ($1-100\;{\mu}g/ml$) resulted in a significant recovery from t-BHP-induced cell death and increased Bcl-2 and procaspase-3 expression, whereas the expression of Bax and cleaved PARP were decreased in a dose-dependent manner compared to the control. Furthermore, Hwabuk 94 inhibited the t-BHP-induced p38 MAP kinase and extracellular signal-regulated kinase 1/2, but not c-Jun N-terminal kinase activations. Finally, these findings suggest that Hwabuk 94 kiwifruit might attenuate t-BHP-induced PC12 cell cytotoxicity, at least in part, through the inhibition of signaling pathways mediated by the ERK1/2 and p38 MAP kinase.

• Journal of Sericultural and Entomological Science
• /
• v.50 no.2
• /
• pp.93-100
• /
• 2012

To investigate the effects of Protaetia. brevitarsis extracts on the protection against liver damage by carbon tetrachloride($CCl_4$) in rat, two kinds of experiment were performed, firstly by the primary hepatocyte culture and secondly by the animal feeding. The primary hepatocyte culture with the extracts of P.brevitarsis showed significantly low activities of GPT, bile acid, and bilirubin, indicating an excellent protective effect against liver damage by $CCl_4$. Especially, below molecular weight 1,000 blew the water to have 32.1% recovery degree. In the seconde experiment, serum GPT activity was significantly decreased in water fraction of P. brevitarsis compared to $CCl_4$ treatment by 98.2%. Serum concentration of bile acid and bilirubin were tended to increased by $CCl_4$ treatment, but water fraction of P. brevitarsis and silymarin recovered the level. These consistent results in vitro and in vivo suggest that the extracts of P. brevitarsis may have strong protective effects against liver damage induced by the potential toxicants such as $CCl_4$.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.13 no.2
• /
• pp.147-155
• /
• 2008

A series of experiments were conducted to find standard test organisms and to develop test protocols for sediment toxicity tests using indigenous amphipods inhabited in Korean coastal environments. The indigenous amphipods Mandibulophoxus mai and Monocorophium acherusicum were well associated with various sediment substrates from sand to mud. The tolerance limits to various physico-chemical factors affecting bioassay results such as temperature, salinity and total ammonium as well as the sensitivities to contaminants in water and sediments were investigated using M. mai and M. acherusicum in the present study. These amphipods were tolerable to the adequate ranges of salinity ($10{\sim}30\;psu$), temperature ($10{\sim}25^{\circ}C$) and ammonia (<50 ppm). They have relevant sensitivities to the reference toxicants, dissolved cadmium as well as other metals and organic pollutants, when compared to the standard test species used in other countries. Field-sediment toxicity tests revealed that M. mai would be more sensitive to sediment-associated pollutants than M. acherusicum, while the sensitivity of M. acherusicum was comparable to those of other sediment test species in other countries. Overall results of this first attempt to develop an amphipod sediment toxicity test protocol in Korea indicated that M. mai and M. acherusicum should be applicable in the toxicity assessment of contaminated sediments, following the further evaluation encompassing various ecological and toxicological evaluation and the standardization of test method.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.13 no.2
• /
• pp.156-163
• /
• 2008

Luminescent bacterial toxicity test was first introduced in the early 1980s, registered as international standard method in 1998 and now widely used as a common toxicity test method. This toxicity test uses luminescent bacterium, Vibrio fischeri, originated from marine environment as a test organism. The degree of toxicity can be evaluated from the comparison of luminescent emission intensity between control and treatment groups to toxicants and materials from various environmental matrix for 30 min. This test can be carried out by using commercial products and its results are sensitive and precise. This research is on the feasibility of adopting luminescent bacterial test as a domestic standard test protocol. Using commercial products, a series of experiments were conducted to identify the precision and accuracy of injection volume and light emission, and to evaluate concentration-response relationship between chemical concentrations and light emissions. Also, the feasibility of the application to environmental media and quality assurance/quality control were checked. The results of serial toxicity tests revealed that the preliminary luminescent bacterial toxicity test was robust and suitable as a standard method.

• Applied Microscopy
• /
• v.32 no.4
• /
• pp.385-398
• /
• 2002

The purpose of the present study is to investigate whether stromal cells supporting specific microenvironment for hematopoiesis of bone marrow are affected by toxicants and therapeutic drugs such as antibiotics and anticancer drugs and whether laminin-1 is associated with such effects. SD rats were intraperitoneally injected with 75 mg/kg of cyclophosphamide which is widely used to treat infant's solid tumor, leukemia and myeloma and sacrificed after 3 days, 1 week, 3 weeks or 5 weeks of injection. The bone marrow extracted and paraffin-sectioned was analyzed using immunohistochemical staining. A part of tissues was subjected to electron microscopy following reaction with rabbit anti-laminin antibody, biotinylated goat anti-rabbit IgG conjugated with 12 nm gold particles, and staining with uranyl acetate. 1. The bone marrow tissue at day 3 post injection with cyclophosphamide displayed dilated venous sinus, partial necrotic death, and decreased number of hematopoietic cells. Laminin-1 was intensively stained in the reticular and adipose tissues. 2. Up to 5 weeks post injection, laminin-1 was stained at a low level in the stromal tissue of bone marrow and the number of hematopoietic cell was increased. 3. Deposition of the gold particle which represents laminin-1 expression was observed at the highest level in the stromal cells of bone marrow obtained 3 days after injection, and decreased after 1 to 5 weeks. These results suggest that stromal cells which play a role in supporting microenvironment for bone marrow hematopoiesis augment induction of laminin-1 expression and activation upon administration of cyclophosphamide.

• Korean Journal of Environmental Biology
• /
• v.36 no.1
• /
• pp.43-49
• /
• 2018

The toxic assessment of the PBDEs (BDE-47, BDE-209) has been comprehensively investigated by using the rates of survival and population growth in the marine rotifer, Brachionus plicatilis. Chiefly, the survival rate was determined after a measurement of 24 hours of exposure to the BDE-47 (2,2'4,4'-Tetrabromodiphenyl ether) and the BDE-209 (2,2',4,4'-Decabromodiphenyl ether) was performed. The BDE-47 reduced survival rate in dose-dependent manner and a significant reduction were noted to have occurred at a concentration of greater than $3.9mg\;L^{-1}$, but the BDE-209 had no effect which was subsequently observed in this study. The population growth rate (r) was determined after 72 hours of exposure to toxicants in the study. It was observed that the r value in the controls (absence PBDEs) was greater than 0.5, and that it decreased as the dose-dependent manner as recorded. The survival rate when exposed to BDE-47 and BDE-209, $EC_{50}$ value was $13mg\;L^{-1}$ and $>1,000mg\;L^{-1}$, and population growth rate was $3.67mg\;L^{-1}$ and $862.75mg\;L^{-1}$, respectively. Therefore, the BDE-47 is considered to be 76-235 times more harmful than the BDE-209 as noted. In this study, the ecotoxicological bioassay using a noted survival rate and population growth rate of B. plicatilis can be used as a baseline data for the continued establishment of the environmental quality standard of the incidences of the BDE-47 and BDE-209 in a marine environment.