• The Korean Journal of Zoology
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• v.17 no.2
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• pp.51-56
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• 1974

Newborn Armenian and Chinese hamsters inoculated with adenovirus type 12 developed undifferentiated small cell tumors as early as 27 days after inoculation in the Chinese hamsters and within 30$\\sim$45 days in the Armenian hamsters. These tumors were transplantable and epithelial-like cell in morphology. Cultures of 6 tumors underwent spontaneous reversion to fibroblast-like morphology during the 14$\\sim$20 in vitro passages in the absence of chromosomal disturbances. While epithelial-like tumor derivatives were oncogenic and positive for the T-antigen, fibroblast-like revertants were non-oncogenic and negative for the T-antigen. Two other tumor derivatives reverted to fibroblast-like forms, immediately following exposure to SV40. These lacked the adenovirus T-antigen but were positive for the SV40 T-antigen and formed sarcomas in animals.

• Korean Journal of Environmental Biology
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• v.23 no.4
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• pp.390-397
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• 2005

The inhibition of cell recovery might be proceeded via either the damage of the mechanism of the recovery itself or via the formation of irreversible damage which could not be repaired at all. Both these processes may take place at the same time. Any of these possibilities would result in a decrease in both the rate and extent of cell recovery. To distinguish them, a quantitative approach describing the process of recovery as a decrease in the effective radiation dose was applied to experimental data on the recovery from potentially lethal damage in Chinese hamster cells exposed to X-rays alone or combined with various chemicals (pyruvate, novobiocin, lactate, nalidixic acid, 3-aminobenzamide). For these particular cases, it is concluded that the recovery process itself is not damaged and the inhibition of the recovery is entirely due to the enhanced yield of the irreversibly damaged cells.

• Korean Journal of Veterinary Research
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• v.13 no.2
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• pp.111-118
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• 1973

The placentation in the golden hamster (Mesocricetus auratus) and the morphological changes occuring in its placenta from implantation to parturition have been observed by light microscope. The results obtained were summarized as follows. 1. The development of the placenta in the fertilized ovum implanted on the day 5 of gestation was described with increasing gestational age. 2. On the day 8 of gestation, the chorioallantoic placenta was formed by fusion of the allantois to the chorion of ectoplacental cone. 3. On the day 13 of gestation, Reichert's membrane with the parietal yolk sac disappeared in a circumscribed area antimesometrially.

• The Korean Journal of Food And Nutrition
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• v.9 no.2
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• pp.123-136
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• 1996

IPSKCDNA gene(1.8 kbp) encoding rat brain IP3K enzyme contained Not I restric site in open reading frame. The Not I sequence, GCGGCCGC, was converted to GCAGCCGC by site-directed mutagenesis. The mutated IP3KcDNA was digested with EcoR I and ligated with EcoR I-restricted psp72·Not2 vector. The resulting psp72 · Not2-IP3KCDNA was digested with the Not I restriction enzyme and then subcloned into the Not I -digested PZIP · NeoSV(X) mammalian expression vector. The PZIP · NeoSV(X) -IPSKCDNA was transfected into CCL39 hamster lung fibroblast cells. The efficiency of the expressed IPSKCDNA gene was significantly higher than expected generally, not only a mean 5-fold increase in the amount of enzyme, but also 16-fold increase in enzyme activity from tractsfected CCL39 cells by the method of Western blot using anti-lP3K antibodies. Both distribution of IPSK in various rat tissues and biochemical properties were discussed.

• Korean Journal of Animal Reproduction
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• v.9 no.2
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• pp.153-157
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• 1985

Ejaculated and epidiymal goat spermatozoa were preserved for 0, 6, 12 adn 18 h, and 0 and 18 h in a semi-aerobic condition at 20-$25^{\circ}C$, and preincubated for 5-6 h in a CO2 incubator in m-KRB solution. Then they were preincubated at different concentrations (3-5, 25-48 and 105-190$\times$107/ml), and ability of penetration into zona-free hamster eggs in vitro was examined. When ejaculated spermatozoa were preincubated in m-KRB solution after presservation for 12 and 18 h, 12 and 29% of zona-free eggs were penetrated, and only 4% of eggs were penetrated by epididymal spermatozoa which were preincubated after preservation for 18 h. When spermatozoa were preincubated at a low concentration, the penetration rates were very low. But when the sperm concentration during preincubation was 25-48 and 105-190$\times$107/ml, the penetration rates increased to about 30%.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.15-15
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• 2002

Telomere erosion is the earliest chromatin modification in cells entering the apoptotic regime. The purpose of this investigation was to demonstrate that loss of telomeric DNA was involved in the induction of mitotic catastrophe and cell death of Chinese hamster Don cells that were grown continuously without subculturing for several days. Don, which is a diploid male Chinese hamster-derived cell line, was grown without sub-culturing for one to four days at 37℃ and then harvested for cytological preparations. (omitted)

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.1036-1040
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• 2007

Sodium butyrate (NaBu) has been used to enhance protein expression levels in mammalian cell culture. To determine the clonal variability of recombinant Chinese hamster ovary (rCHO) cells in response to NaBu addition regarding specific antibody productivity $(q_{Ab})$, three rCHO clones were subjected to different concentrations of NaBu. For all three clones, NaBu addition inhibited cell growth and decreased cell viability in a dose-dependent manner. On the other hand, the enhancing effect of NaBu on $q_{Ab}$ varied significantly among the clones. NaBu addition enhanced the antibody production of only one clone. RT-PCR analysis revealed that the changes in $q_{Ab}$ correlated linearly with those of the mRNA transcription level. Thus, it was concluded that the different enhancing effects of NaBu on protein expression in rCHO cell clones resulted from their different mRNA transcription levels.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.2
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• pp.173-177
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• 1989

Defective or inadequate semen quality, usually presenting as low sperm count or poor sperm motility , is recognizable by semen analysis. However, the ability of spermatozoa to fertilize an ovum is not determined used in various experiments. In this study, hamster oocyte sperm penetration assay was used to determine the fertilizing capacity of sperms in 20 subjects which divided into two groups, group A with 10 normal fertile men, and group B with 10 infertile men. The % penetration in group A and group B were 61% and 35% respectively, which showed statistically not significant but fertilization index was significantly different between group A(FI=2.24) and group B(FI=O.05). Additionally it seemed that the percentage of sperm penetraton was influenced more by the motility of spermatozoa than by the number.

• Korean Journal of Veterinary Research
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• v.15 no.2
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• pp.233-240
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• 1975

Glycogen and alkaline phosphatase were studied histochemically in the placenta of the golden hamster (Mesocricetus auratus). The results were summarized as followings: 1. The histochemical distribution of glycogen and alkaline phosphatase was described in the various cells of both the placenta and uterus from implantation (5 days past coitum) parturition. 2. Glycogen appeared in the extraembryonic ectorm of the implanting ovum and increased gradually in the ectoplacental cone with the development of the placenta. 3. Glycogen granules began to accumulate in the labylinthine trophoblast of chorioallantoic placenta at 10.5 days and in the endodermal cells the visceral yolk sac sac at 10 days, respectively, and in these both cells glycogen increased gradually until the 13 days post coitum and after this time decreased progressively. 4. Alkaline phosphatase activity was high in the labyrinth, junctional zone and decidua, but was not observed in the yolk sac and trophospongium.

• Journal of Veterinary Clinics
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• v.19 no.4
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• pp.464-466
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• 2002

A case of spindle cell tumor was presented in a 16-month-old, female syrian hamster. In the left chest area, a 3cm firm elevated recurrent mass was found, surgically removed, and submitted to the Department of Veterinary Pathology, Seoul National University for diagnosis. The mass was soft to firm and tan on sectioning, and contained hemorrhagic area. Histologically, the tumor was composed of sheets of interlacing bundles of spindle-shaped cells with moderate amount of cytoplasm and oval to fusiform nuclei. They were plemorphic and contained 1 to 3 prominent nucleoli. Based on the gross and histological findings, the tumor was diagnosed as a subcutaneous spindle cell tumor. However, the exact origin of neoplastic cells remained undetermined.