• Korean Journal of Animal Reproduction
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• v.9 no.2
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• pp.148-152
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• 1985

When goat spermatozoa were preincubated for 4-6 h and 6 h in the uteri isolated from hamster and rat, and for 6 h in the hamster uterus in situ, they developed the ability to penetrate zona-free hamster eggs in vitro. Zona-free hamster eggs were not penetrated after insemination with goat spermatozoa preincubated in the isolated hamster uterus 4 h before and 2 h after expected time of ovulation, respectively. Zona-free hamster eggs were not penetrated after insemination with goat spermatozoa preincubated for 4 h in the isolated hamster uterus, but 10 and 18% of eggs were penetrated by spermatozoa preincubated for 5 and 6 h in the isolated uterus.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.1
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• pp.65-72
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• 2001

Objectives: This study was to investigate the fertilization rate after intracytoplasmic sperm injection (ICSI) or partial zona dissection (PZD) of human and hamster sperm into hamster oocyte in in vitro fertilization (IVF). In addition, the possibility of clinical application was evaluated by the comparison of usefulness and difference of these method. Materials and Methods: Hamster immature oocytes were obtained from oviducts superovulated by PMSG and hCG, and hamster sperms were obtained from epididymis. The freezed human sperms were thawed before use. Fertilization were confirmed by two pronuclei, one pronucleus, swollen sperm head or/and two polar bodies at $7{\sim}8$ hour after ICSI or PZD. Results: The fertilization rates after ICSI and PZD of human sperm to hamster oocyte were 3.6%, 64.2%,73.6%, and 55.6% for negative control, positive control, ICSI, and PZD respectively, suggesting that ICSI only showed improved fertilization rate (p<0.01). The fertilization rates after ICSI and PZD of hamster sperm to hamster oocyte were 11.1%, 51.2%, 39.6%, and 72.7% for negative control, positive control, ICSI, and PZD respectively, suggesting that PZD only showed improved fertilization rate (p<0.01). PZD showed significantly higher fertilization rate than ICSI (p<0.05). Conclusions: As for the fertilization rate by ICSI and PZD using hamster oocyte in IVF, ICSI technique was considered to be more useful for human sperm and PZD technique for hamster sperm. Therefore, ICSI technique was considered more appropriate for experimental application using human sperm and hamster oocyte.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.67-76
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• 1996

The methods that make Hantavirus grow consist of inoculation into the experimental animals and cultured cells. The cultured cells, such as Vero-E6 and A549 cells, have been usually used for isolation of the virus and the animals, such as mice and rats, are used for large scale preparation of the virus so far. Furthermore, the cell can be used to maintain the virus and assay the infectivity and the animals can be used for the experiment of viral pathogenicity and challenge for assessment of vaccine. Apodemus mice, the own natural host of the virus, has been used for challenge test of Hantaan virus. However it has been pointed out to difficult handling and breeding the animal in laboratory. Therefore, we attempted to establish a new animal model for challenge test at the time of isolation of Maaji virus which is a new hantavirus similar but distinct to Hantaan virus. In suckling hamster, the titer of Maaji virus and the lethality to mice of the virus were increased gradually in the titer and lethality through passage by intracerebral (IC) inoculation. We tried to re-adapt this brain virus to lung of weanling hamster. The brain passaged virus was inoculated into weanling hamster intramuscularly. Again, the titer of the virus in lung was also increased by continuous passage of this virus. This facts could regarded as adaptation to new environment in which the virus proliferates. To identity the virus passaged in hamster with Maaji virus, both of the virus passaged in hamster brain and lung were compared with Maaji virus (MAA-I) and Hantaan virus (HTN 76-118) by means of restriction fragment length polymorphism (RFLP) and slingle strand conformation polymophism (SSCP). As a result, we conclude that Maaji virus could be adapted successfully to weanling hamster through this passage strategy. Utilizing this adapted Maaji virus strain, hamster model is able to be used for challenge test in hantaviral vaccinology and further experiments utilizing hamster system as a rather available and convenient lab animal are expected.

• The Korean Journal of Physiology
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• v.27 no.1
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• pp.93-105
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• 1993

The present study was performed to investigate the properties of ionic currents elicited by voltage pulses in the unfertilized eggs of mouse and hamster by using the whole cell voltage clamp techniques and to find out if there are any differences in properties between eggs of the two rodents. In addition, the modulatory effect of G proteins and protein kinase C (PKC) on the ionic channels were observed. The inward current in hamster eggs was shown to be due to $Ca^{2+}\;current\;(i_{ca})$). The current voltage relations of these currents in hamster egg were analogous to those in mouse eggs. The amplitude of $i_{ca}$ in the hamster egg was larger than that in the mouse egg ($-3.12{\pm}1.07\;nA\;vs.\;-1.71{\pm}0.71\;nA,\;mean{\pm}\;SD$). These results suggest that the $Ca^{2+}$ channels in both kinds of eggs have similar channel properties but their density, and/or conduct ance per unit area is higher in hamster eggs than in mouse eggs. Outward currents in eggs of both mouse and hamster were carried by $K^+$. In hamster eggs, they appeared to comprise at least two components; a transient outward component ($i_{to}$) and a steady state component ($i_{\infty}.$ The $i_{to}$ was found to be dependent on intracellular $Ca^{2+}$ concentration; whereas on the other hand $i_{\infty}\;was\;Ca^{2+}$-independent. $Ca^{2+}$ currents were increased in eggs treated with GTP (or $GTP{\gamma}S$) or fluoroaluminate ($AIF_4^-$). In the hamster egg these increments were antagonized by GDP (or $GDP{\beta}S$) application. In contrast to the enhancement of $i_{ca},\;i_k$ was reduced following GTP (or $GTP{\gamma}S$) perfusion in mouse eggs. The transient component ($i_{to}$) in hamster eggs was increased by adding GTP but decreased by phorbol ester, TPA or dioctanoyl glycerol (DOG). Simultaneous application of $GTP{\gamma}S$ and DOG suppressed $i_{to}$ more effectively than a single application or DOG or TPA. From the above results, we have shown that ionic currents elicited by voltage pulses existed in the unfertilized eggs of mouse and hamster. There are at least two types of currents, $i_{ca}\;and\;i_k$ in mouse eggs, while three types, $i_{ca},\;Ca^{2+}$-dependent $i_k$ and $Ca^{2+}$-independent $i_k$ exist in hamster eggs. ionic channels in these eggs may be regulated either directly by GTP and PKC or indirectly by the substances linked with GTP and PKC.

• Development and Reproduction
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• v.26 no.3
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• pp.107-115
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• 2022

Kisspeptins, products of KISS1 gene, are ligands of the G-protein coupled receptor (GPR54), and the kisspeptin-GPR54 signaling has an important role as an upstream regulator of gonadotropin releasing hormone (GnRH) neurons. Interestingly, extrahypothalamic expressions of kisspeptin/GPR-54 in gonads have been found in primates and experimental rodents such as rats and mice. Hamsters, another potent experimental rodent, also have a kisspeptin-GPR54 system in their ovaries. The presence of testicular kisspeptin-GPR54 system, however, remains to be solved. The present study was undertaken to determine whether the kisspeptin is expressed in hamster testis. To do this, reverse transcription-polymerase chain reactions (RT-PCRs) and immunohistochemistry (IHC) were employed. After the nest PCR, two cDNA products (320 and 280 bp, respectively) were detected by 3% agarose gel electrophoresis, and sequencing analysis revealed that the 320 bp product was correctly amplified from hamster kisspeptin cDNA. Modest immunoreactive (IR) kisspeptins were detected in Leydig-interstitial cells, and the weak signals were detected in germ cells, mostly in round spermatids and residual bodies of elongated spermatids. In the present study, we found the kisspeptin expression in the testis of Syrian hamster. Further studies on the local role(s) of testicular kisspeptin are expected for a better understanding the physiology of hamster testis, including photoperiodic gonadal regression specifically occurred in hamster gonads.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.189-203
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• 1999

To determine sex of bovine embryos using hamster histocompatibility Y(H-Y) antibodies, bovine compact morulae were incubated for 6 hours in TCM199 supplemented with 10% hamster H-Y antiserum and the embryos with developmental arrest were diagnosed as male embryos, while the embryos showing development during the incubation as female embryos. This presumptive embryo sexing was confirmed by polymerase chain reaction(PCR)method. 1. In the result of hamster sperm cytotoxicity test to measure H-Y antibody titer, the rate of dead sperm was considerably lower in H-Y antiserum absorbed with hamster male splenocytes than in H-Y antiserum absorbed with hamster female splenocytes or H-Y antiserum unabsorbed with splenocytes(p<0.01). 2. The rate of oocytes fertilized in vitro and the rate of blastocysts of the fertilized oocytes were 58.5% and 32.4%, respectively. The rate of blastocysts on day 8 was 15.9%, denoting the highest rate during whole culture period posterior to in vitro fertilization (IVF). 3. The bovine 16 cell and compact morulae embryos incubated in the medium supplemented with hamster H-Y antibodies showed 37.1% and 48.9% of developmental arrest which were diagnosed as male, respectively, and rates of redeveloped embryos from the arrested were 24.1% in 16 cell and 44.3% in compact morulae embryos, respectively, denoting higher rate of sex determination and rate of redevelopment in compact morulae than 16 cell embryos. 4. Bovine compact morulae of Korean cattle and Holstein were treated with hamster H-Y antibodies for sex determination and the rates of developmental arrest(diagnosed as male) were 48.4% for Korean cattle and 47.9% for Holstein, respectively. The rates of redeveloped embryos to blastocyst after treatment were 42.6% for Korean cattle and 41.8% for Holstein, respectively, showing no significant differences of sex determination and redevelopment between both breed. 5. The sex determination of bovine embryos(Korean cattle and Holstein) using hamster H-Y antibodies was diagnosed by PCR for confirmation, denoting the rates of 86.1% for Korean cattle and 85.9% for Holstein male embryos, respectively, and the rates of 91.9% for Korean cattle and 90.1% for Holstein female embryos, respectively, with no significant differences of sex determination between both breed. These results indicated that hamster H-Y antibodies can be usable for sex determination of bovine embryos of Korean cattle and Holstein, the viability of bovine embryos was sustained while being cultured in the medium supplemented with hamster H-Y antibodies of appropriate titer and sex determination of bovine embryos by PCR can be feasible for confirmation.

• Korean Journal of Veterinary Service
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• v.44 no.4
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• pp.305-308
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• 2021

A female Chinese hamster with unknown age was referred for acute onset of anorexia, depression, and large cyst from the head to body. After referring, the patient died shortly. During necropsy, severe hemorrhage in the cyst, multiple mass on liver, and transformed right kidney were found. The infection was confirmed by cytology, cultures and PCR of 16S ribosomal RNA gene. This report describes a first case of naturally occurred systemic Klebsiella oxytoca infection in a household Chinese hamster.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.305-315
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• 2001

In this study, the production of transgenic embryo was attempted by microinjection or round spermatid cultured with foreign DNA. At first, the expression of haploid spermatids specific gene, mTP1 in mouse and hPrm2 in hamster spermatids were investigated by RT-PCR method in testes of young mice and hamster testis. The specific gene expression first appeared at 18 days post partum (dpp) in mice spermatid and 20 dpp in hamster spermatid. Therefore, the round spermatids isolated from 17 dpp mice and 19 dpp hamster were used for the introduction of foreign EGFP gene into haploid round spermatids. For the introduction of EGFP gene haploid round spermatids suspended in medium including EGFP gene were treated with a different electric field strength at 0.11, 0.18 and 0.44 ㎸/cm. After electrical stimulation, viability of testicular sperm cells and 67.6%, 66.4% and 49.9%, in mice and 62.6%, 57.9% and 27% in hamster, respectively. These values were significantly lower than those of non-treated control groups 80.5% in mouse and 69.1% in hamster After 72 hrs culture, the highest expression rate of EGFP gene, 28.5% in mice and 32.1% in hamster were obtained from tile spermatogenic cells electroporated by the field strength or 0.18 ㎸/cm. Then, the ability of fertilization and embryonic development of haploid spermatids transfected with foreign EGFP gene were estimated by the microinjection of spermatids into hamster oocytes. The Irate pronuclear formation rate (77.5%) was lower than non-treated control (80%), and the cleavage rate of the treated group (58.8%) was lower than control (65%). To prove the foreign EGFP integration in hamster embryos, 2-cell stage hamster embryos were subjected to the observation under the fluorescence microscope, and the PCR analysis. As a result, about 44% of 2-cell embryos were showed the integration of EFGP gene into their genome. Therefore, These results suggest the possibility to produce transgenic hamsters by microinjection of haploid spermatid transfected with foreign DNA.

• Toxicological Research
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• v.17 no.1
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• pp.11-15
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• 2001

This study was carried out to evaluate the irritant potential of A mouthwash in hamster cheek pouch. The test substances were applied twice daily to right pouches of hamsters for 14 consecutive days. Animals were administered with A mouthwash, Listerine, saline and control solution, respectively. In order to evaluate the irritant potential in mucosa of hamster cheek pouch, we observed clinical signs, mortality, body weight changes and gross and histopathological findings for 14 days. In all groups, there were neither dead animals nor significant changes of body weights. In addition, there were no differences between saline and A mouthwash treated group in gross and histopathological findings. Therefore, these results suggest that there was no irritant potential of A mouthwash in hamster cheek pouch.

• Journal of Veterinary Clinics
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• v.39 no.3
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• pp.126-130
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• 2022

A 17-month-old intact male Djungarian hamster (Phodopus sungorus) was presented with an axillary mass. Fine needle aspiration cytology of the mass showed a malignant epithelial cell tumor. Histopathological examination of the surgically removed mass confirmed a complex apocrine gland adenocarcinoma. Twenty days postoperatively, the mass recurred in the same area, and the patient died while waiting for the second surgical removal. This is the first report of the cytology, histopathology, and postoperative recurrence of apocrine gland adenocarcinoma in a Djungarian hamster.