• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.60-66
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• 1999

Diethylnitrosamine (DEN) is known as a potential hepatic carcinogen by single administration. This study was designed to measure the effects of DEN-induced cell damage on the triglyceride and cholesterol concentration in the liver, excluding dietary effects. Fertilized chicken eggs, 10 days before hatching, were randomly divided into three groups (n=20) and each egg was injected 10 ${mu}ell$ of corn oil (vehicle control), 5 $\mu\textrm{g}$ of DEN/10 ${mu}ell$ of DEN/10 ${mu}ell$ into yolk via air sac. After 48 hr and 96 hr incubation, the damage of the chick-embryo liver cell was investigated by electron microscopy and by measuring the concentration of lipid components (total cholesterol, free cholesterol, phospholipid and triglyceride). For eggs administered 10 $\mu\textrm{g}$ of DEN and incuvated 96 hr, in hepatocyte, the nucleus membrane was roughed, the size of nucleolus was apparently increased and euchromatin was accumulated. Mitochondria were condensed and cristae, located mitochondiral inner membrane, were obscured. Additionally, the leaves of triglyceride and cholesterol classes were significantly increased depend on the amount treated with 10 $\mu\textrm{g}$ DEN at 96 hr, but phospholipids component of cell membrane, were decreased with significance. As a conclusion, carcinogen induced hepatic lesion was correlated with the changes in lipid component of liver.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.801-806
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• 2008

A classical technique to study somitic cell fate is to employ the cross-transplantation of quail somites into a chick host. The densely stained nucleoli of the quail cells makes it possible to assess the fate of the donor quail cells in the chick host. Classical somite transplantation techniques have been hampered by the necessity of a small opening in the chick eggshell, difficulty in hatching the offspring and interspecies post-hatch graft rejection. With the advent of transgenic chicken technology, it is now possible to use embryos from transgenic chickens expressing reporter genes in somite cross-transplantation techniques to remove any possibility of interspecies graft rejection. This report describes using a surrogate eggshell system in conjunction with transgenic chick:chick somitic cell cross-transplantation to generate viable chimeric embryos and offspring. Greater than 40% of manipulated embryos survive past 10 days of incubation, and ~80% of embryos successfully cultured past 10 days of incubation hatched to produce viable offspring.

• Journal of the korean veterinary medical association
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• v.16 no.4_5
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• pp.189-192
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• 1980

The studies were undertaken with the objective to observe water distribution and its content in egg during the incubation periods by dry method. The resalts obtained were sammarized as follows: 1. Chick embryo was not recogenizable on second and third day

• The Korean Journal of Zoology
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• v.35 no.2
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• pp.144-148
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• 1992

Insulin and transfenin (Tf) were found to be essential for suwival and differentiation of brain neuroblasts obtained from chick embryo. This requirement, however, is Changed from insulin to Tf upon neuronal development of the embryo, and this phenomenon is due to the changes in the levels of corresponding receptors. Using cultured neuroblasts, the level of Tf receptor is also found to increase Lvhile that of insulin receptor falls dramatically during the course of the cell differentiation. These results suggest that the development-specific changes in the levels of insulin and Tf receptors in embryo can be reproduced in the culture system during the differentiation period. Because the culture system used was a defined medium and contained no other macromolecules than insulin and Tf, it appears possible that insulin and Tf may act as signalling molecules in the control of neuronal development.

• Applied Microscopy
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• v.29 no.4
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• pp.459-470
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• 1999

To investigate the changes during the differentiation of the cerebral neurons of the embryogenic day (ED) 9 and 10, investigated the ultrastructural changes in the cerebral neurons by Electromicroscope, also cerebral protein, the activity of dehydronases (LDH, MDH and SDH) and changes of adenosine triphosphate concentration were analyzed, the result obtained are as follows. In the ultrastructural changes in the cerebral neurons, chromatin in 9 day-old chick embryos are comparatively distributed to even in neucleoplasm and could investigate very prominently that nuclear membrane is double-layer. Esperially, Rough endoplasmic reticulum (RER) and Golgi complex are developed well, also polysome is investigated and synaptic vesicles were scattered. In 10 day-old chick embryos, chromatin evenly spread and nuclear membrane could be differentiated prominently. Rough endoplasmic reticulum (RER) contain cytoplasm, mitochondria and Golgi complex are comparatively developed well. In 9 day-old cultural group of chick embryo cerebrum were separated 37 polypeptide bands and In 10 day-old cultural group of chick embryo cerebrum were separated 38 poly -peptide bands. The more culture time increase, the more the activity of dehydronases (LDH, MDH and SDH) increase. LDH activity was 11.07 (9th day) and 12.12 (10th day), MDH activity was 11.89 (9th day) and 13.44 (10th day) and SDH activity was 8.45 (9th day) and 10.52 (10th day) respectively. The ATP concentration degreesed 10 day-old cultural group than 9 day-old cultural group.

• Applied Microscopy
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• v.42 no.3
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• pp.142-146
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• 2012

Doublecortin (DCX) is a microtuble-associated protein that is required for the migration of immature neuroblasts within the chick and mammalian brain. Although it is generally thought that DCX is expressed only in the neuroblasts, some mature neurons maintain DCX expression; for example, horizontal cells in adult rat retina. In this study, we demonstrate that retinal neural progenitors in the early embryonic stage of the chick also expressed DCX, as do developing ganglion cells and horizontal cells in later stages of development. These findings raise the possibility of a role for DCX in retinal neural progenitors, before they become specialized into neuroblasts in the chick.

• Applied Microscopy
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• v.26 no.2
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• pp.123-136
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• 1996

To investigate the effect of aflatoxin $B_1$, on survival rate and ultrastructure of liver during chick embryogenesis electron microscopic methods were used. After injection of aflatoxin $B_1$ into the yolk, ultrastructural changes in the liver of chicken embryo were observed. The results were as followed. 1. 12-day old chicken embryos were treated with single injection of aflatoxin $B_1$ with the dose of $0.0005{\mu}g,\;0.005{\mu}g,\;0.05{\mu}g,\;0.5{\mu}g,\;2.5{\mu}g,\;5.0{\mu}g$ each. Chicken embryos treated with the dose of $0.5{\mu}g$ of aflatoxin $B_1$ had survival rate of 22%. The embryos treated with $2.5{\mu}g$ of aflatoxin $B_1$ hardly survived. 2. Chicken embryos treated with $0.05{\mu}g$ of afatoxin $B_1$ had hatched in 30%, but once hatched, they all survived. 3. After administration of $0.05{\mu}g$ of aflatoxin $B_1$ into the 12-day old chicken embryo, the electron microscopic studies were examined during development stages. The nuclei of hapatocytes became irregularly shaped and the structures of endoplasmic reticulum were changed to spherical types at 20-day old chicken embryo. Also, mitochondria became to be dilated and severe fibrosis was induced in the cytoplasm. However, the hepatocytes became almost normal in 30-day old young chicken.

• The Korean Journal of Zoology
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• v.31 no.3
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• pp.207-217
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• 1988

A myotrophic protein that seemed to he eseentiai for the hision of chick embryonic myoblasts in culture was isolated from chick embryo extrad and was found to be identical or at least similar to the iron-transporting protein, transferrin. Embryo extract seemed to contain, in addition to this myotrophic protein, a heat stable protein that inhibits the fusion of myoblasts. Iron seemed to he necessary for myoblasts to fuse and it was supposed that the role of the myotrophic protein m myoblast fusion is to supply iron to the cell. The numher of the myotrophic protein receptors on myoblast surface membrane decreased immediately after the start of myoblast fusion, supposedly due to the decreased need of iron after the fusion once commenced. It was estimated that endocytosis of myotrophic protein took about 10 minutes and one recycling about 2 hours. The accumulation of iron in myoblasts continued linearly with cultre time and endocytosis of the myotrophic protein occured at a constant rate.

• The Korean Journal of Zoology
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• v.29 no.3
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• pp.215-233
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• 1986

The effect of tryptophan on brain formation at the early stage of chick embryo has been investigated morphologically using electron microscope. The electron micrographs of cerebral cortex cells of $5\\sim10$ day old chick embryo, which received 1.0mg of tryptophan showed that the irregularity, evagination and disruption of nuclear membrane and nuclear chromatin condensation, nucleolar chromatin margination and segragation. Hypertrophy of stalks, vesicles, and vacuoles can be seen and dilation and vesiculation of rough endoplamic reticulum and polysome disaggregation occured. Protein and RNA levels and the activity of several enzymes such as lactate dehydrogenase, succinate dehydrogenase, malate dehydrogenase and glucose 6-phosphate dehydrogenase of tryptophan administered group were significantly lower than those of control group suggesting that the tryptophan administration depressed protein biosynthesis resulting in the decrease of enzyme activity. It was found that serotonin content of egg yolk which has been incubated for 10 days were as much as three times that of control egg yolk. It is not clear whether the increase of serotonin content might inhibit intracellular yolk granule degradation which might result in malformation of chick embryo, but it is likely that tryptophan administration might depress protein biosynthesis, consequently, the enzyme biosynthesis would be impaired. This might give rise to improper development of chick embryo.

• The Korean Journal of Zoology
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• v.31 no.3
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• pp.191-206
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• 1988

Chick embryos which have received a single injection of the organophosphate compound,malathion (0.1 mg, 0.5 mg, 1.0 mg or 2.0 mg in 0.05 ml of corn oil) via the yolk sac at certain times (2 daya, 4 days or 6 days after incubation) have been investigated. After 9 days of incubation, chick embryos were harvested to investigate the effects of malathion on the development of cerebrum morphologically and biochemically. The effects of simultaneous injection of malathion and nicotinamide were also compared. On ultrastructural examination, neurons in cerebral cortex showed to be inhibited in their differentiation by malathion; nuclear irregularity, swelling of endoplasmic reticulum, and cytoplasmic vacuoles were observed. On cytochemical study of acetylcholinesterase(AChE) by electron microscope, the positive reaction products of this enryme were localized at the membrane of nucleus and endoplasmic reticulum of neurons. Inhibition of AChE activty was severe in groups treated with relatively low doses, which was consistent with the results of spectrophotometric analysis. The activity of lactate dehydrogenase(LDH) of cerebrum in groups treated with malathion was higher than that of the control group. The nicotinamide adenine dinucleotide(NAD) content of chick embruo treated with malathioti decreased significantly, and nicotinamide coinjection raised the NAD level as compared with the control group, thus preventing malathion-induced momhological alteration. In conclusion, it is suggested that malathion changes the ultrastructure of differentiating neurons and alters some enzyme activities in chick embryo cerebrum, and the severity of which is consistently dose-or age-dependent.