• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.203.2-203.2
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• 2003

• Proceedings of the Korean Society of Life Science Conference
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• 2002.03a
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• pp.88-88
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• 2002

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.444-451
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• 1998

The changes of amine, nitrate and nitrite nitrogen in yellow corvenia were studied during its processing and storage in order to clarify the precursors of N-nitrosamine(NA) formation in the salted and dried yellow corvenia(Gulbi), prepared y using the different salting method like dry and brine salting by pure and curde salt. As a result, during the processing and storage of Gulbi, DMA and TMA contents were significantly increased in the yellow corvenia. And after 40 days storage the increase rate showed 25.7∼45.7, 3.3∼5.6 times higher than those of 0.3, 2.4mg/kg, respectively, while nitrite contents, during its processing and storage, were scarcely changed in the salted and dried yellow corvenia. During the processing and storage, of Gulbi, DMA and TMA contents were less produced in brine salted and dried yellow corvenia using crude salt than in sample prepared using were scarcely changed in the salted and dried yellow corvenia. During the processing and storage of Gulbi, DMA and TMA contents were less produced in brine salted and dried yellow corvenia using crude salt than in sample prepared using pure salt, while the former were more effective than the latter in inhibiting the production of nitrate and nitrite. Therefore, it was revealed that reduction of NA precursors such as DMA, TMA, nitrate and nitrite were more effective in preparing with the brine salting method than with the dry salting method.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.683-688
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• 2003

Caffeine (1,3,7-trimethylxanthine), a central nervous system stimulant, is contained in various foods, beverages and over-the-counter medications. Sulfadimethoxine (SDM) is one of the anti-thyroid agents and induces proliferation of thyroid capsule in two stage thyroid carcinogenesis model using N-bis(2-hydroxypropyl)nitrosamine (DHPN). In this study, we examined the effect of caffeine on fibrous proliferation of thyroid capsule in DHPN and SDM-treated rats. Five-week-old male F344 rats were given a single subcutaneous injection of DHPN (2,800 mg/kg, body weight). Starting one week thereafter, SDM (1,000 ppm in drinking water) with or without caffeine (1,500 ppm in diet) was administered for 12 weeks. All animals were autopsied and histopathological examination of the thyroid glands was performed. Thyroid follicular proliferative changes were induced in all rats treated with DHPN+SDM. In addition, the proliferation of perithyroidal fibrous tissue and pleomorphic thyroid follicular cells within the capsule were observed in DHPN+SDM treated group. Caffeine would not be related to these lesions in this experimental condition. although pentoxifylline, a methyl xanthine derivative, has an anti fibrotic effects.

• Toxicological Research
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• v.31 no.3
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• pp.279-288
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• 2015

N-nitrosamines, which are classified as carcinogens by IARC and US EPA, can be easily found in various foods. They are reaction products between nitrogen oxide and secondary amines, but can also be generated during fermentation. Ever since the 1960s, when nitrite, used as a preservative in processed meats, was suspected to generate N-nitrosamines, the usage of the food additive has been debated. However, the benefit of nitrite in food supply could not be ignored and the risk-benefit analysis has become a key issue in the use of the additive. For a risk analysis, an accurate estimation of the hazardous material is necessary; therefore, analytical methods for nitrosamines have continuously evolved from the 1950s. Solid supported liquid-liquid extraction and solid phase extractions have replaced the distillation for the clean-up steps, and tandem mass spectrometry is employed for higher selectivity and sensitivity. In the present study, for a better estimation of N-nitrosamine intake, the total diet study samples were prepared for the N-nitrosamines analysis. In order to obtain the most sensitive results, a partial preparation procedure was developed and modified for different food matrices. Among seven N-nitrosamines (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosodibutylamine, N-nitrosopiperidine, N-nitrosopyrrolidine, and N-nitrosomorpholine) analyzed in the present study, N-nitrosodiethylamine has shown the highest detection rate in agricultural foods, while N-nitrosodimethylamine has appeared most frequently in livestock and fishery food products. The concentration of N-nitrosodimethylamine was the highest in seasoning.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.247-258
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• 1994

A total of 31 commercial dried marine food products, consisting of 14 fishes, 2 shellfishes and 2 seaweeds species were analyzed for their contents of precusors of N-nitrosamine such as dimethylamine(DMA), trimethylamine(TMA), trimethylamine oxide (TMAO), betaine and nitrate and nitrite nitrogen as factors of N-nitrosamine formation. Carcinogenic N-nitrosamines were extracted by a steam distillation apparatus and were analyzed for their components using a gas chromatography-thermal energy analyzer. N-nitrosodimethylamine(NDMA) was confirmed by a gas chromatography-mass spectrometry. The contents of betaine nitrogen in samples were in the range of $5.2{\sim}373.8mg\%$ and were significantly higher than tertiary amines such as TMA and TMAO. DMA nitrogen in those samples was in the range of trace-31.2ppm and was high, in the dried shark(31.2ppm), alaska pollack($22.9{\sim}24.3ppm$) and octopus($17.9{\sim}18.4ppm$). In dried laver and sea mustard, however, amines were not detected at all. The levels of nitrate nitrogen in the dried marine samples ranged from zero to 16.8ppm and were high in the dried stingray(16.8ppm), alaska pollack(16.3ppm) and squid($2.2{\sim}12.4ppm$), but were less than 1.0 ppm in other samples. The levels of nitrite nitrogen were lower than those of nitrate nitrogen and it was not detected in dried sea cucumber, laver and sea mustard. Twenty eight of 31 samples contained NDMA($range=1.2{\sim}86.0ppb$), which was the only volatile N-nitroso compound found. The NDMA levels of dried stingray($2.8{\sim}86.0ppb$), alaska pollack($8.2{\sim}55.5ppb$), squid($3.3{\sim}53.2ppb$), yellow corvenia($45.9ppb$) and plain dried shrimp($15.4{\sim}17.9ppb$) were high. However, it was not detected in dried sea cucumber, laver and sea mustard. Samples, containing high levels of NDMA, also contained high nitrate and nitrite nitrogen. From above results, it can be concluded that nitrate and nitrite were major factors for the formation of NDMA in dried marine food products.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.129-134
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• 2001

Since NNK is one of the most abundant tobacco-specific alkaloids and a strong carcinogenic nitrosamine, it has been used for evaluating a potential of carcinogenicity in the animal models. The present study has attempted to examine the potential of carcinogenicity of NNK in human epithelial cells, from which the cell type the most of cancers including oral cancer and nasal cavity cancer are originated. The cellular model used for the study is a human keratinocyte cell system immortalized by Ad12-SV40 hybrid virus. The cellular system has successfully been used for the carcinogenicity studies because of its limitless life span, epithelial morphology and nontumorigenicity. When cells were treated with a variety of NNK concentrations, levels of saturation density and soft agar colony formation were increased in a dose-dependent fashion. Colonies of large cell aggregates were above 5 at the higher doses. The results indicate that exposure of human cells with NNK induced loss of contact inhibition and increases of anchorage independence and cellular adhesion, which are typical characteristics of the neoplatically transformed cells. When cells were exposed with 100uM NNK for 2hr, mRNA levels of IL-1 and PAI-2 were increased in a dose-dependent manner, but expression of TGF- 1 was not affected. While expression of growth regulatory factors were altered with a short-term exposure, there was no alteration of these factors in the NNK-transformed cells. However, mRNA levels of fibronectin were increased both in the short-term treatment and in the transformation. The results suggest that altered expression of extracellular matrix such as fibronectin following short-term exposure might be fixed in the genome and these altered properties be continuously transfered throughout the cell division. Western blot analysis showed a translocation of PKC- from cytosolic fraction to the particulate fraction, indicating a possible role of NNK in the signal transduction pathway. The present study provided an evidence that NNK in the smoking may be associated with epithelial origin cancer such as oral and nasal cavity cancers. In addition, this study suggested that altered expression of extracellular matrix and PKC may play an important role in the carcinogenic mechanism of NNK.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5287-5290
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• 2012

Throughout human history, plant products have been used for many purposes including as medicines. Herbal products and spices can be used as preventive agents against cancer due to their antimicrobial, antioxidant and antitumorigenic properties. This study was designed to evaluate the potential protective effect of curcum in rats administered nitrosamine precursors; dibutylamine (DBA) and sodium nitrate (NaNO3); and infected with Escherichia coli (E. coli) and also to monitor changes in nuclear factor the Kappa B p65 (NF-${\kappa}B$ p56) pathway and its downstream products, Bcl-2 and interleukin-6 (IL-6), in parallel with nitrosamine precursors, E. coli and curcum treatment. Rats were divided into three groups (n=25 each; except of control group, n+20). Group I a normal control group, group II administered DBA/NaNO3 in drinking water and infected with E. coli and group III was administered DBA/NaNO3 in drinking water, infected with E. coli and receiving standard diet containing 1% curcum powder. Histopathological examination reflected that the curcum treated group featured a lower incidence of urinary bladder lesions, and lower levels of NF-${\kappa}B$, Bcl-2 and IL-6, than the group receiving nitrosamine precursor and infected with E. coli. These findings suggested that curcum may have a protective role during the process of bladder carcinogenesis by inhibiting the NF-${\kappa}B$ pathway and its downstream products.

• Proceedings of the Korean Society of Life Science Conference
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• 2002.03a
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• pp.87-87
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• 2002

• Preventive Nutrition and Food Science
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• v.8 no.4
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• pp.321-329
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• 2003

In order to provide data on N-nitrosamine (NA) and sanitation in fish available in domestic markets, this study analyzed the levels of NA and its precursors in 9 samples of sea breams and yellow croakers, 12 samples of red-flesh fish, 38 samples of white fish, 5 samples of Alaska pollacks and cod, and 8 species of imported fish. Sea breams and yellow croakers had nitrite concentrations ranging from non-detectable (ND) to 7.4 mg/kg, red fish ND to 5.3 mg/kg, white fish ND to 18.7 mg/kg, Alaska pollacks 0.3 to 2.2 mg/kg, and imported fish from 0.4 to 12.8 mg/kg. Nitrates in sea breams and yellow croakers ranged from 1.2 to 41.19 mg/kg, red fish 0.6 to 26.1 mg/kg, white fish 4.3 to 75.9 mg/kg, Alaska pollacks 0.4 to 3.1 mg/kg, and imported fish ND to 16.0 mg/kg. DMA concentrations were 69.8 to 219.9 mg/l00 g in sea breams and yellow croakers, 4.1 to 336.3 mg/l00 g in red fish, 1.3 to 331.9 mg/l00 g in white fish, 15.7 to 312.3 mg/l00 g in Alaska pollacks, and 1.0 to 71.8 mg/l00 g in imported fish. TMA concentrations in sea breams and yellow croakers, red fish, white fish, Alaska pollacks and imported fish were 43.8∼496.2, 12.3∼127.0, 2.0∼525.9, 15.4∼122.4, and 4∼70.6 mg/l00 g, respectively. For NA in fish distributed in local markets, only N-nitro-sodimethylamine (NDMA) was detected, and its concentrations ranged from 4.7 to 73.7 $\mu\textrm{g}$/kg in sea breams and yellow croakers, 2.2 to 56.5 $\mu\textrm{g}$/kg in red fish, ND to 143 $\mu\textrm{g}$/kg in white fish, 3.8 to 33.3 $\mu\textrm{g}$/kg in Alaska pollacks, and 2.1 to 102.2 $\mu\textrm{g}$/kg in imported fish.