• Parasites, Hosts and Diseases
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• v.50 no.3
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• pp.207-213
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• 2012

The egg morphology of minute intestinal flukes (MIF) that can occur as human infections in the Republic of Korea, i.e., Metagonimus yokogawai, M. miyatai, M. takahashii, Heterophyes nocens, Heterophyopsis continua, Stellantchasmus falcatus, Stictodora fuscata, Pygidiopsis summa, and Gymnophalloides seoi, was studied in comparison with Clonorchis sinensis. The adult worms were obtained from residents of endemic areas, and their intrauterine eggs were studied and measured using light microscopy; the length, width, length-width ratio (LWR), and Faust-Meleney index (FMI). Several specimens were processed for scanning electron microscopy (SEM), and before gold-coating, the uterine portion of each fluke was etched with a sharp pin in order to expose the eggs. The MIF eggs were ovoid, pyriform, or elliptical with a size range of $21-35{\times}12-21{\mu}m$. S. fuscata eggs revealed the highest FMI (largest in the area) and lowest LWR, whereas P. summa eggs showed the lowest FMI and medium LWR. SEM revealed that G. seoi and S. fuscata had remarkably clean shell surface lacking the muskmelon-like structure which is prominent in C. sinensis eggs. In Metagonimus spp., H. continua, H. nocens, and S. falcatus eggs, minute surface ridges were recognizable though less prominent compared with C. sinensis. On the surface of P. summa eggs, thread-like curly structures were characteristically seen. The results revealed that important differential keys for MIF eggs include the length, width, area (FMI), shape of the eggs, and the extent of the muskmelon-like structure or ridges on their shell surface and operculum.

• Korean Journal of Human Ecology
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• v.17 no.6
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• pp.1065-1077
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• 2008

The purpose of this study was to verify whether BND test was an appropriate tool for diagnosis of attachment security and to investigate difference of responsive Characteristics to the Bird's Nest Drawings according to parents attachment degree. The subjects in the study were 525 students, selected from senior high schools in D-city. The instruments used were parents attachment scale and Bird's Nest Drawings, and Discriminant analyses and crosstab analyses were used. The results were as follows. First, attachment indicators in the Bird's Nest Drawings discriminated according to group of parents attachment. Second, for male student, there was a significant difference placement nest, eggs, entire birds family, quality of line and tree picture according to attachment to father. For female student, there was a significant difference eggs, entire birds family, quality of line and tree picture according to attachment to father. For male student, there was a significant difference nest contents, placement nest, eggs, entire birds family, quality of line and tree picture according to attachment to mother. For female student, placement nest, space, nest size, eggs, entire birds family and quality of line according to attachment to mother.

• Parasites, Hosts and Diseases
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• v.57 no.1
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• pp.49-53
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• 2019

Contaminated liver fluke egg in the environment has led to the high prevalence of human opisthorchiasis associated with cholangiocarcinoma in Southeast Asia. To find the effective lessening methods of Opisthorchis viverrini eggs in the contaminated environment, we investigated the temperature conditions for killing of these trematode eggs in vitro. Numerous O. viverrini eggs were obtained in the proximal part of uteri of adult worms from experimental hamsters. Mature eggs with miracidium were allocated by experimental groups (2 control: positive and negative and 4 treatment: 50, 60, 70, and $80^{\circ}C$) with 0.85% saline, and treated by the experimental plan. Eggs in each experimental groups were observed under the confocal microscope after stain with Propidium Iodide (PI) to evaluate the effect of temperatures. Eggs in 70 and $80^{\circ}C$ groups were all killed after over 10 min heated. Majority of eggs in $60^{\circ}C$ (10, 15, and 30 min heated), 70 and $80^{\circ}C$ (5 min heated) groups were inactivated. However in $50^{\circ}C$ group, below half of eggs were to be killed in all time lapse (10, 15 and 30 min). In order to prevent O. viverrini infection and cholangiocarcinoma, direct treatment of sewage by heating at 70 or $80^{\circ}C$ at least 10 min is essential. Therefore, treatment of O. viverrini eggs at a high temperature is a potential method for controlling egg contamination in sewage.

• Parasites, Hosts and Diseases
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• v.51 no.4
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• pp.489-492
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• 2013

A paleoparasitological survey to detect helminth eggs was performed in archaeological sites of Jeolla-do and Jeju-do, the Republic of Korea. Total 593 soil samples were collected in 12 sites of Jeolla-do and 5 sites of Jeju-do from April to November 2011, and examined by the methods of Pike and coworkers. A total of 4 helminth eggs, 2 eggs each for Trichuris trichiura and Ascaris sp., were found in soil samples from 1 site, in Hyangyang-ri, Jangheung-eup, Jangheung-gun, Jeollanam-do. The egg-recovery layer was presumed to represent a 19th century farm, which fact suggested the use of human manures. This is the third archaeological discovery of parasite eggs in Jeolla-do. Additionally, no helminth eggs in archaeological sites of Jeju-do is an interesting problem to be solved in the further investigations.

• Parasites, Hosts and Diseases
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• v.55 no.1
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• pp.21-29
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• 2017

Schistosoma haematobium is a biocarcinogen of human urinary bladder (UB). The present study investigated developing UB cancer mouse model by injecting S. haematobium eggs into the bladder wall and introduction of chemical carcinogens. Histopathological findings showed mild hyperplasia to epithelial vacuolar change, and high grade dysplasia. Squamous metaplasia was observed in the S. haematobium eggs+NDMA group at week 12 but not in other groups. Immunohistochemistry revealed significantly high expression of Ki-67 in urothelial epithelial cells of the S. haematobium eggs+BBN group at week 20. The qRT-PCR showed high expression of p53 gene in S. haematobium eggs group at week 4 and S. haematobium eggs+BBN group at week 20. E-cadherin and vimentin showed contrasting expression in S. haematobium eggs+BBN group. Such inverse expression of E-cadherin and vimentin may indicate epithelial mesenchymal transition in the UB tissue. In conclusion, S. haematobium eggs and nitrosamines may transform UB cells into squamous metaplasia and dysplasia in correlation with increased expression of Ki-67. Marked decrease in E-cadherin and increase in p53 and vimentin expressions may support the transformation. The present study introduces a promising modified animal model for UB cancer study using S. haematobium eggs.

• Clinical and Experimental Reproductive Medicine
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• v.11 no.2
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• pp.51-57
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• 1984

The success of human in vitro fertilization (IVF) & embryo transfer (ET) has focused attention on the culture conditions that can provide optimal development of the preimplantation embryo. Studies of in vitro fertilization using mouse have direct implications to human IVF, since similar conditions are used for both species. Mouse IVF as a quality control system for human IVF & ET was studied since Feb., 1984. The results were as follows: 1. Egg retrieval following superovulation in IeR mice was l5.1${\pm}$5.3 eggs ovulated/mouse (Mean${\pm}$ S.D.) 2. In vitro cleavage rate was 61.7% (1146 eggs cleaved/l858 eggs inseminated) and % blastocyst was 42.6%. 3. In comparison with two media of Ham's F-10 and m-KRB, in vitro cleavage rate were 40.9%/63.l% and %blastocyst were 44.3%/61.2% (P<0.05). 4. It was concluded that mouse IVF system has a valuable place in human IVF & ET as a quality-control system and in human reproductive physiology as a research model.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.6
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• pp.822-826
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• 2007

This study was conducted to determine the effects of a 0.5% sodium alginate eggshell coating, that was applied at two temperatures, 5 and $25^{\circ}C$, by examining the degree of microbial inhibition on the eggshell surface as well as the coating's effects on egg quality during storage. A significant portion of human Salmonella enteritidis infection is traced to food contamination, and eggs are often highly exposed to this type of contamination. The 0.5% sodium alginate coating's effect for inhibiting microbial growth on the eggs, at $25^{\circ}C$ for 7 days, was one hundred thousand times more effective than that of the uncoated eggs. The pH level in eggs increases as the eggs lose $CO_2$ and as the storage temperature increases. We found that the pH of the coated eggs was lower than that of the uncoated eggs. The pH for the uncoated eggs changed from 7.72 to 7.94 over 30 days of storage at $5^{\circ}C$. However, when the eggs were coated with 0.5% sodium alginate, the pH changed from 7.72 to 7.85 over 30 days of storage at $5^{\circ}C$. The Haugh unit was 66.02 for the uncoated eggs and 70.37 for the 0.5% sodium alginate coated eggs after 30 days of storage. The yolk index of the eggs coated with sodium alginate was higher than that of the uncoated eggs after 30 days. These results indicate that a sodium alginate coating on eggs can serve as protection from microbes and is effective in preserving the interior quality of eggs.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.463-468
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• 2016

Contamination by foodborne pathogens and mycotoxins was examined in 475 eggs and 20 feed samples collected from three egg layer farms, three egg-processing units, and five retail markets in Korea. Microbial contamination with Salmonella species, Escherichia coli, and Arcobacter species was examined by bacterial culture and multiplex polymerase chain reaction (PCR). The contamination levels of aflatoxins, ochratoxins, and zearalenone in eggs and chicken feeds were simultaneously analyzed with high-performance liquid chromatography coupled with fluorescence detection after the post-derivatization. While E. coli was isolated from 9.1% of eggs, Salmonella species were not isolated. Arcobacter species were detected in 0.8% of eggs collected from egg layers by PCR only. While aflatoxins, ochratoxins, and zearalenone were found in 100%, 100%, and 85% of chicken feeds, their contamination levels were below the maximum acceptable levels (1.86, 2.24, and 147.53 μg/kg, respectively). However, no eggs were contaminated with aflatoxins, ochratoxins, or zearalenone. Therefore, the risk of contamination by mycotoxins and microbes in eggs and chicken feeds is considered negligible and unlikely to pose a threat to human health.

• Food Science of Animal Resources
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• v.38 no.3
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• pp.615-628
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• 2018

Preserved egg, a kind of alkaline-fermented food, is a traditional egg product in China. Here, we investigated the nutritional functions of preserved eggs by in vivo and in vitro experiments. The results of in vivo studies showed that the levels of triglycerides (TG), total cholesterol (TCHO) and low-density lipoprotein cholesterol/high density lipoprotein cholesterol (LDL-C/HDL-C) were significantly decreased (p<0.05) in the liver of rats treated with preserved eggs. Meanwhile, the levels of two important cancer markers, interleukin-6 (IL-6) and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), were also significantly decreased (p<0.05) in treated rats. In vitro studies were performed on Caco-2 cells, a human epithelial colorectal adenocarcinoma cell line. It demonstrated that the gastrointestinal (GI) digests of preserved eggs significantly accelerated (p<0.05) the apoptosis by upregulating caspase-3 in the Caco-2 cells. Besides, after treated with preserved eggs, the half maximal inhibitory concentration (IC50) of preserved eggs digests to Caco-2 cells was 5.75 mg/mL, indicating the significant inhibition of cell proliferation provided by preserved eggs (p<0.05). The results shown in this study demonstrated that preserved eggs may be a novel functional food involved with antilipemic, anti-inflammatory activity as well as the effect on accelarating the apoptosis of Caco-2 cells.

• Journal of Environmental Health Sciences
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• v.6 no.1
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• pp.1-9
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• 1979

An experimental study was carried out to develop a rural type toilet of which the effluent could not transmit parasitic diseases at a village in Kangwon Province, Korea, during the period of January through December 1978, A drum tank (dia. 57cm$\times$90cm) and a cement tank (100cm$\times$100cm$\times$100cm) were filled with human excreta collected from toilets of the villages (the ratio of feces to urine was estimated approximately 1: 5) at once and three threecompartment toilets were constructed and used by people. pH, temperatures and viability of parasitic eggs were examined with the content of toilets. Rusults are summarized as follows: 1. pH increased from 7.0 at the beginning of experiment to 7.5 or 8.0 after 4 months of storage in drum tank as well as in cement tank and so did from 7.0~7.5 in the first tank to 8.0~8.5 in the third tank of all three-compartment toilets. 2. Temperatures of content at middle part of toilets in January through March ranged from 2 to 6$\circ$C which were 2-4$\circ$C higher than those of air, and those of lower part were again 1~2$\circ$C higher than of middle part. but temperatures of air, at middle part andat lower part in April were 14$\circ$C, 9~10$\circ$C and 8~9$\circ$C respectively, in July 29$\circ$C, 20~21$\circ$C and 19~20$\circ$C respe ctively and in October 17$\circ$C, 14$\circ$C and 14~13$\circ$C respectively. 3. All the parasitic eggs were degenerated about 4 months after filling drum tank with human excreta on 10th April while 10% of eggs were degenerated on 15th May, and all the eggs were degenerated about 4 months after filling cement tank on 24th August while about 10% were degenerated on 11th September and 20% on 4th October. 4. Degeneration rates of eggs were only 5~15% at 5cm below surface in the first tanks of three-compartment toilets while 45~65% at 50cm below, and concentration rates of eggs in second tanks were 8~12% of those in first tanks and only a few eggs were found in third tank but all of them were degenerated. Specific gravity of liquid of 1.022~1.024 in second tanks was not enough for overflowing eggs into third tanks.