• Korean Journal of Veterinary Service
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• v.39 no.3
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• pp.167-174
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• 2016

In this study, we analyzed for the changes of low organic compounds during 4 weeks incubation though inoculation of harmful microorganisms on commercial feed. Two percent of overnight cultures of Exiguobacterium acetylicum, Acinetobacter calcoaceticus, Aspergillus flavus and Fusarium graminearum were inoculated in feed, respectively. After adjusting moisture level to 50% for the promotion of feed spoilage, pH was decreased to 4.58~5.03 and microorganism was ranged to $6{\sim}10log_{10}CFU/g$. The compounds were compare between aflatoxin G1 producing feeds and aflatoxin G1 non-producing feeds. Aflatoxins G1 were detected by the immunoaffinity column clean-up method with HPLC-FLD, and were confirmed in samples incoulated by Aspergillus flavus and Acinetobacter calcoaceticus. Koiganal II, cyclohexanol and butadien-one were detected from samples (the non-sterilized inoculated feed) by Aspergillus flavus and Acinetobacter calcoaceticus. Respectively as aflatoxin G1 pre-detected substance, Koiganal II, cyclohexanol and butadien-one may be useful substance for the pre-detection of aflatoxin G1.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.247-250
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• 2012

Raw milk samples (n=28) obtained from milk tanks in 3 dairy plants of different regions and commercial milks (n=100) were collected from six cities. These samples were analyzed for the level of aflatoxin $M_1$ contamination using immunoaffinity columns and high performance liquid chromatography coupled with fluorescent detectors. Confirmation of aflatoxin $M_1$ ($AFM_1$) identified in positive samples was based on the formation of the hemiacetal derivative ($AFM_{2a}$) after derivatization with trifluroacetic acid. The average concentrations of aflatoxin $M_1$ in the raw milks were 25.1 ng/kg, and those values in commercial milks were 29.8 ng/kg. The highest level of aflatoxin $M_1$ in milk was 72.7 ng/kg. These results showed that the contamination of aflatoxin $M_1$ in milks consumed in the Korea was quite low compared to the standard in Korea Food Code (aflatoxin $M_1$ 500 ng/kg).

• Environmental Mutagens and Carcinogens
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• v.20 no.1
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• pp.34-39
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• 2000

Although shipbuilding workers were exposed to a variety of genotoxic compounds including polycyclic aromatic hydrocarbons (PAHs), limited number of studies were conducted to evaluate the biomarkers related to PAH exposure in painting workers in shipbuilding industry. One hundred and thirty three workers including 73 employees using coal tar paints were recruited from a shipbuilding company located in South Korea. Urinary 1-hydroxypyrene glucuronide (1-OHPG), as internal dose of PAH exposure, were measured by synchronous fluorescence spectroscopy after immunoaffinity purification using monoclonal antibody 8E11. Glutathione S-transferase (GST)M1 and GSTT1 genotypes were assessed by multiplex PCR. Information on demographic characteristics, smoking gabit, diet, job title, use of personal protective equipments were collected by self-administered questionnaire. Urinary 1-OHPG were higher in workers using coal tar paints than in workers using general paints, however, the difference was not statistically significant (p=0.20, Mann-Whitney U test). Urinary 1-OHPG levels in smokers were higher than in non-smokers (p<0.05 by Mann-Whitney U test) and there was a significant increase in urinary 1-OHPG levels with the numbers of cigarettes consumed per day (Spearman's correlation coefficient = 0.28, p=0.02). Genetic polymorphisms of GSTM1 and GSTT1 did not influence the level of 1-OHPG in study subjects. Multiple regression analysis show that smoking is the only significant predictor for lon-transformed 1-OHPG (overall model R2=0.1). These results suggest that workers using coal tar paints were exposed to significant amount of PAHs and individual difference in xenobiotic metabolism might affect the levels of internal dose of PAHs.

• Biomedical Science Letters
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• v.15 no.1
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• pp.37-45
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• 2009

Insect cell cultures have become important tools in the production of biological substances for use in a variety of research, human and veterinary medicine, and pest control applications. These applications often require the introduction of foreign DNA into the cells and have generally used methods originally developed for use with human and other mammalian cell cultures. While these methods can be successfully employed, they are often less efficient with insect cells and frequently involve complex procedures or require specialized equipment. Even when they do work, they may require substantial modification because of differences in the culture medium or growth patterns of insect cells. In this study, We have optimized transfection conditions of Sf9 cell line using insect expression vector pIZT/V5-His which expresses green fluorescent protein effectively. Human stem cell factor (hSCF) is a glycoprotein that plays a key role in hematopoiesis acting both as a positive and negative regulator, often in synergy with other cytokines. It also plays a key role in mast cell development, gametogenesis, and melanogenesis. It can exist in membrane-bound form and in proteolytically released soluble form. As determined by an enzyme-linked immunosorbent assay performed, hSCF level in supernatant averaged 995ng/ml. The human hSCF was partially purified by immunoaffinity chromatography and analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. The results show that the hSCF has N-linked carbohydrate and corresponds to the soluble form, at or about 223 amino acids in length. The findings suggest functional importance for soluble hSCF in cells.

• Parasites, Hosts and Diseases
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• v.29 no.1
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• pp.1-8
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• 1991

Out of many component proteins in crude saline extract of Spirometra mansoni plerocercoid (sparganum) , 36 kDa and 29 kDa proteins were found to be the most antigenic and were already purified by immunoaffinity chromatography using monoclonal antibody as a ligand. In this study, a single step purification of these potent antigenic proteins of sparganum extract was investigated. When the crude saline extract was charged to gelatin-Sepharose 4B affinity column, 36 kDa and 29 kDa protein fractions were bound. SDS-polyacrylamide gel electrophoresis (PAGE) and SDS-PAGE/immunoblot confirmed that the bound protein to gelatin was serologically pure. When evaluated by ELISA with patients sera, the purified protein of 36 and 29 kDa also showed improved antigenicity.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.140-142
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• 2006

Because ochratoxin A recovery level of Makgeolli is lower (<50%) than those of other commodities such as rice, barley, and beer, Makgeolli was evaluated to improve the recovery and enable routine analysis. Use of 3% sodium bicarbonate instead of phosphate-buffered saline as homogenizing solution provided good recovery of ochratoxin A (>80%) spiked in Makgeolli at level of 1 ppb. To determine if this analytical method is reliable for ochratoxin A detection in Makgeolli, survey was conducted for ochratoxin A in 30 sterile Makgeolli samples retailed in Korea. Only two wheat-based Makgeolli samples contained detectable level of ochratoxin A (0.8 and 2.1 ppb) as confirmed by HPLC- electrospray ionization- mass spectrometry. Extraction of sample with 3% sodium bicarbonate for 3 min, followed by cleanup of extracts with immunoaffinity columns, and HPLC with fluorescence detection provided dependable detection of ochratoxin A in Makgeolli samples.

• Analytical Science and Technology
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• v.24 no.2
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• pp.150-157
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• 2011

Aflatoxins are secondary metabolites of the molds of Aspergillus flavus and Aspergillus parasiticus. They are highly carcinogenic compounds and can affect a wide range of vegetable commodities such as cereals (especially corn), nuts, peanuts, fruits and oil seeds, in the field and during storage. In fact, oilseeds are often stored for weeks in conditions that promote the mould growth, and the possible consequent presence of aflatoxins in oilseeds can lead to their transfer in oil. In addition, aflatoxins can be found as a natural contaminant in multi-cereals and beans making baby food for infants and young-children. The objective of this study was to validate the liquid extraction method or develop an analytical method for edible oil and infant-children foods. Therefore, this study developed condition of extract for aflatoxins ($B_1$, $B_2$, $G_1$ and $G_2$) in edible oil using a high performance liquid chromatography with florescence detector (HPLC/FLD). Aflatoxins were extracted from edible oil samples by means of MSPD (Matrix solid phased dispersion), utilizing $C_{18}$ as dispersing material and purified by using immunoaffinity column. The gression line coefficients were above 0.999. The recoveries for aflatoxins ranged from 85.9 to 93.0%, and relative standard deviations were below 5.7%. The new developed method of aflatoxins effectively enhanced recoveries by using MSPD-Immunoaffinity column compared with liquid extraction. The analytical method for liquid extraction of aflatoxin was appropriate for infant-children food. Reviewing the current method, the recoveries of aflatoxins ($B_1$, $B_2$, $G_1$ and $G_2$) were 89.5~92.3%.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.317-324
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• 2020

In order to create the national food nutrient database, a total of 41 animal foods (ham, seafood, edible insects and eggs) were analyzed for their vitamin B₁₂ content and the applied immunoaffinity-HPLC was verified. Ham vitamin B₁₂ contents were 0.30-0.65 ㎍/100 g. Seafood showed relatively high vitamin B₁₂ level, where the values of fermented clam were the highest (26.80 ㎍/100 g) followed by fermented pollack roe. Vitamin B₁₂ was not detected in silkworm pupae and beetles, while relatively high levels were found in the two-spotted cricket imago (6.70 ㎍/100 g). Chicken and quail egg yolk had roughly 100- and 30-times higher vitamin B₁₂ levels as compared to their egg white. Vitamin B₁₂ contents in quail and chicken eggs were significantly enhanced by boiling (p<0.05). Results based on accuracy (97-102% recovery) and precision (<5% RSD) indicate that this study provides reliable vitamin B₁₂ information on animal foods consumed in Korea.

• Journal of Nutrition and Health
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• v.54 no.2
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• pp.211-223
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• 2021

Purpose: A total of 39 seafood menus were prepared according to the Korean standard recipe, and analyzed for vitamin B₉ (folate) and B₁₂ (cobalamins) contents, using validated applied analytical methods. The menus included Guk/Tang/Jjigae (boiled or stewed dishes, n = 10), Bokkeum (stir-fried dishes, n = 10), Jjim/Jorim (braised or steamed dishes, n = 7), Gui (baked or grilled dishes, n = 7), Twigim (deep-fried dishes, n = 2) and Muchim (dried or blanched-seasoned dishes, n = 3). Methods: The contents of vitamin B₉ and B₁₂ in all food samples were determined by the trienzyme extraction-Lactobacillus casei and immunoaffinity-high-performance liquid chromatography/photodiode array detection methods. Analytical quality control was performed in order to assure reliability of the analysis. Results: Accuracy (97.4-100.6% recoveries) and precision (< 6% relative standard deviations for repeatability and reproducibility) of vitamin B₉ and B₁₂ analyses were determined to be excellent. The vitamin B₉ and B₁₂ contents of the 39 seafood menus evaluated, varied in the range of 1.83-523.08 ㎍/100 g and 0.11-38.30 ㎍/100 g, respectively, depending on the ingredients and cooking methods. The vitamin B₉ content was highest in Jomi-gim (523.08 ㎍/100 g), followed by Geonsaeu-bokkeum (128.34 ㎍/100 g) and Janmyeolchi-bokkeum (121.53 ㎍/100 g). Vitamin B₁₂ was detected in all seafood menus, with highest level obtained in Kkomack-jjim (41.58 ㎍/100 g). The seaweed dish was found to have high levels of both vitamin B₉ and B₁₂. All assays were performed under strict quality control. Conclusion: Guk and Tang menus, which contain a large amount of water, were relatively lower in the vitamin B₉ and B₁₂ contents than the other menus. Bokkeum menus containing various vegetables were high in the vitamin B₉ content, but the vitamin B₁₂ content was dependent on the type of seafood used in the menu.

• Molecules and Cells
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• v.26 no.2
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• pp.175-180
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• 2008

$I{\kappa}B$ kinase (IKK), the pivotal kinase in signal-dependent activation of nuclear factor-${\kappa}B$ (NF-${\kappa}B$), is composed of multiple protein components, including IKK ${\alpha}/{\beta}/{\gamma}$ core subunits. To investigate the regulation of the IKK complex, we immunoaffinity purified the IKK complex, and by MALDI-TOF mass spectrometry identified a splice variant of zinc finger protein 268 (ZNF268) as a novel IKKinteracting protein. Both the full-length and the spliced form of the ZNF268 protein were detected in a variety of mammalian tissues and cell lines. The genes were cloned and expressed by in vitro transcription/translation. Several deletion derivatives, such as KRAB domain (KRAB) on its own, the KRAB/spacer/4-zinc fingers (zF4), and the spacer/4-zinc fingers (zS4), were ectopically expressed in mammalian cells and exhibited had different subcellular locations. The KRAB-containing mutants were restricted to the nucleus, while zS4 was localized in the cytosol. TNF-${\alpha}$-induced NF-${\kappa}B$ activation was examined using these mutants and only zS4 was found to stimulate activation. Collectively, the results indicate that a spliced form of ZNF268 lacking the KRAB domain is located in the cytosol, where it seems to play a role in TNF-${\alpha}$-induced NF-${\kappa}B$ activation by interacting with the IKK complex.