• Korean Journal of Ichthyology
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• v.21 no.3
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• pp.141-148
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• 2009

Sex differentiation and gonad development were investigated in a marine medaka species, Oryzias dancena (Beloniformes; Teleostei). The average time to hatch was 11 days post-fertilization (dpf) at $25^{\circ}C$. Primordial germ cell (PGC) was first observed at 5 dpf and migrated to presumptive gonadal area between the gut and pronephric duct at 9 dpf. Male and female gonads were morphologically differentiated at 12 days post-hatching (dph). Early oocytes at perinucleolus stage as well as the formation of spermatid and efferent duct were observed at 28 dph. At 6 weeks of age, the ovary exhibited yolk granulation in many oocytes, while testis possessed a considerable number of spermatogonia and spermatids. The first ovulation was observed in 9-week-old females, and at the same age, males contained fully-matured spermatozoa. Data obtained in this study indicate that the gonad differentiation of O. dancena is the typical type of differentiated gonochorism.

• Korean Journal of Poultry Science
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• v.45 no.1
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• pp.1-15
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• 2018

Salmonella infections in livestock industry cause various problems such as worsening animal welfare and productivity, damaging consumer confidence in the food safety of animal products. Chicken meat and eggs are known as major source of pathogen causing human foodborne infections. Therefore food safety concerns have prompted the poultry producers and governments to introduce the strategy and regulation to control these pathogens. Salmonella can persist for long periods of time in a wide range of spaces including feed bin, feed processing facilities, poultry farm, slaughterhouse, processing plants, etc. For the effective and constant Salmonella control, combination of pre-harvest, harvest and post-harvest measures should be considered comprehensively. The control measures would be most effective at farm level where the contamination initiates. Transmission of pathogen from feed origin to the live poultry and finally to the products was proven already. To control bacteria in the feed ingredients and formula feed, thermal processing, irradiation or chemical treatment may be applied. Chemical treatments to inhibit Salmonella in the feed involve the use of products containing organic acids, formaldehyde, or a combination of such compounds. However, recontamination which might occur during storage and transport process and/or by other various factors should always be under control and eliminated. Feed additives used to control Salmonella in birds' gastrointestinal track can be of various types, including prebiotics, probiotics, organic acids and bacteriophages. Although their mode of action varies, they ultimately inhibit the colonization of Salmonella in the gut and improve the performance of birds. This review describes the strategies that could be adapted to the management of feedstuffs and the use of feed additives in pre-harvest stage to control Salmonella contamination in poultry farming.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.941-946
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• 2001

The effects of various concentrations of saturated fatty acids (SFA; caprylic, capric and stearic acids) on the growth of the anaerobic fungus, Neocallimastix frontalis C5-1 isolated from the rumen of a Korean native goat were investigated. At higher concentrations of fatty acids (0.1%, w/v), the addition of SFA strongly decreased filter paper (FP) cellulose digestion and polysaccharide-degrading enzyme activity. The sensitivity of the rumen anaerobic fungus to the added fatty acids increased in the following order: caprylic ($C_{8:0}$)>capric($C_{10:0}$)>stearic($C_{18:0}$) acid, although stearic acid had no significant (p<0.05) inhibitory effects at any of the concentrations tested. However, the addition of SFA at lower concentrations (0.01 and 0.001% levels), did not inhibit FP cellulose degradation and enzyme activity. Furthermore, although these parameters were slightly stimulated by the addition of SFA, they were not statistically different from control values. This is the first report examining the effects of fatty acids on anaerobic gut fungi. We found that the lower levels of fatty acids used in this experiment were able to stimulate the growth and specific enzyme activities of rumen anaerobic fungi, whereas the higher levels of fatty acids were inhibitory with respect to fungal cellulolysis.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.1
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• pp.129-138
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• 1999

If rumen bacteria can be manipulated to utilize nutrients (i.e., ammonia and plant cell wall carbohydrates) more completely and efficiently, the need for protein supplementation can be reduced or eliminated and the digestion of fiber in forage or agricultural residue-based diets could be enhanced. However, these approaches require a complete and accurate description of the rumen community, as well as methods for the rapid and accurate detection of microbial density, diversity, phylogeny, and gene expression. Molecular ecology techniques based on small subunit (SSU) rRNA sequences, nucleic acid probes and the polymerase chain reaction (PCR) can potentially provide a complete description of the microbial ecology of the rumen of ruminant animals. The development of these molecular tools will result in greater insights into community structure and activity of gut microbial ecosystems in relation to functional interactions between different bacteria, spatial and temporal relationships between different microorganisms and between microorganisms and reed panicles. Molecular approaches based on SSU rRNA serve to evaluate the presence of specific sequences in the community and provide a link between knowledge obtained from pure cultures and the microbial populations they represent in the rumen. The successful development and application of these methods promises to provide opportunities to link distribution and identity of gastrointestinal microbes in their natural environment with their genetic potential and in situ activities. The use of approaches for assessing pupulation dynamics as well as for assessing community functionality will result in an increased understanding and a complete description of the gastrointestinal communities of production animals fed under different dietary regimes, and lead to new strategies for improving animal growth.

• Applied Microscopy
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• v.18 no.2
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• pp.59-76
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• 1988

In order to know the distribution, relative frequencies, types and morphology, endocrine cells in the intestinal tract of the hedgehog(Erinaceus koreanus) were studied by light microscopy, immunohistochemistry and electron microscopy. The results obtained are summarized as follows: 1. Two kinds of endocrine cells were demonstrated with two specific staining methods. Argyrophil cells(reactive cells for Grimelius method) were found most frequently in the intestinal region, and were infrequent in the rectum, whereas argentaffin cells (reactive cells for Masson-Hamperl method) were found most frequently in the rectum and in the other legions were infrequent. These reacting cells were mainly found in the intestinal glands, whereas a small number in the mucosa. 2. Twelve kinds of endocrine cells, gastrin(Gas)-, somatostatin (Som)-, serotonin(5-HT)-, glucagon(Glu)-, bovine pancreatic polypeptide(Bpp)-, cholecystokinin(Cck)-, secretin(Sec)-, motilin(Mot)-, glicentin(Gli)-, gastric inhibitor polypeptide(GIp)-, substance P(Sp)-, and neurotensin(Neu)-immunoreactive cells, were identified by immunohistochemical method. Gas-, Som-, 5-HT-, Glu-, Cck-, Sec-, Mot-, Gli-, Sp-, and Neu-reactive cells were observed in the duodenum, and among these Gas- and 5-HT-reactive cells were moderately found while the others were infrequent. In the jejunoileum Gas-, Som-, 5-HT-, Glu-, Cck-, Mot-, Gli-, GIp-, SP-, and Neu-reactive cells were found, and among these 5-HT- and GIp-reactive cells were moderately found while the others were infrequent. In the colon Sec-reactive cell was not detected. 5-HT-reactive cells were found most frequently and the others were infrequent in this region. 5-HT-, Bpp-, GIi- and Neu-reactive cells were found in the rectum. Among these 5-HT-reactive cells were found most frequently. 3. Electron microscopically, five types of endocrine cells, EC, ECL, D, G, A-like cell, were identified in the intestinal region. EC and ECL cells in the duodenum, EC, D and G cells in the jejuno-ileum, EC and A-like cells in the colon and EC cell in the rectum were observed respectively.

• Journal of the Korean Society of Costume
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• v.52 no.6
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• pp.25-39
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• 2002

The purpose of this study is to look into dressing practices at the Woinarodo region in terms of ordinary and ritual clothes. Men wore Bqji(trousers) and Jeokori(jackets) as their plain clothes and sometimes Jangsam mid Durumaki(topcoat). During the period of Japanese colony, men wore Western-style clothes. For women it was basic to wear Chima(skirts) and Jeokori. And they preferred Momppe rather when in Japanese rule. In arrangements for their head, men put on gut, and had their hair cut during Japanese nile. Women laid a bundle of their braided hairs on the head or braided their hair, while married women did their hair up in a chignon during the ruling period People of the region put on straw and leather shoes, and then rubber ones since the late 1930s. Hand weaving was a major means of living for women at the region. Ramie, hemp and cotton were mainly weaved by hand. Starching was applied mainly to ramie and cotton. Glues for starching were made of raw rices, cooked rices, wheat flour or gloiopeltis tenax. For ritual clothes, especially in wedding, bridegrooms arranged themselves with Samokwandae and then Put on Baji, Jeokori, Durumaki and Danryung. But they Put on Western-style dresses as the liners of Danryung, and wear Nambawi Rather than the Samo after korean independence from Japanese rule. Bridges wore Chima, Jeokori and Wonsam and Chokdoori and covered their face with Hansam Wonsam did not be worn any longer after Korean independence from the rule. Shrouds for funeral ceremony were manufactured with silks, cotton and hemp, when the chief mourner wore hempen hoods and funeral robes, while women, Chima, made of hemp. and any type of Jeokori.

• IMMUNE NETWORK
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• v.13 no.5
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• pp.213-217
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• 2013

Enterotoxigenic Bacteroides fragilis (ETBF) is a human gut commensal bacteria that causes inflammatory diarrhea and colitis. ETBF also promotes colorectal tumorigenesis in the Min mouse model. The key virulence factor is a secreted metalloprotease called B. fragilis toxin (BFT). BFT induces E-cadherin cleavage, cell rounding, activation of the ${\beta}$-catenin pathway and secretion of IL-8 in colonic epithelial cells. However, the precise mechanism by which these processes occur and how these processes are interrelated is still unclear. E-cadherin form homophilic interactions which tethers adjacent cells. Loss of E-cadherin results in detachment of adjacent cells. Prior studies have suggested that BFT induces IL-8 expression by inducing E-cadherin cleavage; cells that do not express E-cadherin do not secrete IL-8 in response to BFT. In the current study, we found that HT29/C1cells treated with dilute trypsin solution induced E-cadherin degradation and IL-8 secretion, consistent with the hypothesis that E-cadherin cleavage causes IL-8 secretion. However, physical damage to the cell monolayer did not induce IL-8 secretion. We also show that EDTA-mediated disruption of E-cadherin interactions without E-cadherin degradation was sufficient to induce IL-8 secretion. Finally, we determined that HT29/C1 cells treated with LiCl (${\beta}$-catenin activator) induced IL-8 secretion in a dose-dependent and time-dependent manner. Taken together, our results suggest that BFT induced IL-8 secretion may occur by the following process: E-cadherin cleavage, disruption of cellular interactions, activation of the ${\beta}$-catenin pathway and IL-8 expression. However, we further propose that E-cadherin cleavage per se may not be required for BFT induced IL-8 secretion.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.198-205
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• 2017

Objective: This study aimed to investigate the effects of single or/and double strains of probiotic supplement on feed efficiency, growth performance, and microbial population in distal gastrointestinal tract (GIT) of weaning rabbits. Methods: Sixty-four weaning (28 days old) New Zealand White rabbits were randomly distributed into four groups with treatments including: basal diet without probiotic supplement (control) or supplemented as follows: $1{\times}10^6cfu/g$ B. subtilis (BS group), $1{\times}10^7cfu/g$ L. acidophilus (LA group), or $0.5{\times}10^6cfu/g$ B. subtilis plus $0.5{\times}10^7cfu/g$ L. acidophilus (BL group). During the research, the male and female rabbits were fed separately. Body weight of the rabbits was recorded at 28, 42, and 70 d of age. Results: There was an increase (p<0.05) in body weight gain for the LA group at 42 d. Rabbits fed BL responsed with a greater growth (p<0.05) and better feed conversion ratio (p<0.05) than those fed with no probiotic. Digestibility coefficients of dry matter, organic matter, crude protein, neutral detergent fiber, and gross energy were higher (p<0.05) in LA and BL groups than those in the control group. Male rabbits had higher (p<0.05) Bacilli spp. and Coliformis spp. in the ileum than female rabbits. Rabbits supplemented with BS had greater (p<0.05) numbers of bacilli in all intestinal segments than those receiving no probiotic, whereas intestinal Lactobacilli populations were greater (p<0.001) in the LA and BL diets compared to control. Average intestinal coliform populations were lowest (p<0.05) in the rabbits supplemented with LA as compared to those fed the control and BS. Conclusion: Supplementation of L. acidophilus alone or in combination with B. subtilis at a half of dose could enhance number of gut beneficial bacteria populations, nutrient digestibility, cecal fermentation, feed efficiency, and growth performance, but rabbits receiving only B. subtilis alone were not different from the controls without probiotic.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.262-270
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• 1994

The established methods in the residue analysis of endosulfan require an extensive sample clean-up prior to quantification by relatively complex equipment. A radioimmunoassay(RIA) provides a simple procedure with theoretically higher sensitivity and specificity necessitating only a minimum of sample clean-up. Endosulfan-specific antibodies were developed in rabbits by using a bovine serum albumin(BSA) conjugate wherein the alcohol form of endosulfan was multiply bound to the protein via succinylation. Produced antibodies showed the high titers to endosulfan-BSA(1 : 32,000). An RIA method was developed in water and carp by using $^{14}C-labeled$ endosulfan as a tracer. The lowest detection amount of endosulfan was 1 ng in the liver, kidneys, gut and water samples, and 3 ng in the whole body sample of carp without any clean-up, corresponding to 0.1 ppb of endosulfan.

• Biomedical Science Letters
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• v.10 no.2
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• pp.121-128
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• 2004

Mast cells and goblet cells have the ability to protect against parasites by increasing mucus production that traps and excludes worms and prevents their intimate contact with the gut mucosa in the host. In this study, we investigated the function of mast cells and goblet cells for the rejection of Echinostoma hortense (E. hortense). In addition, we used both C3H/HeN and BALB/c mice in order to examine whether mast cells and goblet cells function differentially according to the strains of mice. After an oral infection with 30 E. hortense metacercariae, the number of mucosal mast cells and goblet cells, as well as worm recovery rate, were observed in experimentally infected mice between 1 week and 8 weeks post-infection (PI). Worm recovery rates in C3H/HeN and BALB/c mice were 65.7％ and 23％, respectively, in week 1 P.I., indicating that worm expulsion in C3H/HeN mice was higher than in BALB/c mice. Our results demonstrate that the period (week 3 P.I.) in which worm recovery falls rapidly is the same period that the number of goblet cells and mast cells reaches a peak. These results indicate that worm recovery significantly correlates with the growth rate of goblet cells and mast cells (P=0.0482). However, worm expulsion is not associated with goblet cells or mast cells in BALB/c mice.