• Clinical and Experimental Reproductive Medicine
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• 제18권1호
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• pp.73-80
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• 1991

We compared fertilizing potential measurements by the zona-free hamster egg penetration assay with the in vitro fertilization and embryo transfer program was evaevulated for their ability to fertilize zona free hamster egg. Spermatozoa from 12 presumeably fertile donors and from the male partners of 56 infertile couples were evaluated for their ability to fertilizing potentials. Penertration rates of fertile donors were $36.2{\pm}27.7%$ ; Fertilization rates of infertile couples between with normal semen parameters and with abnormal semen parameters were $28.7{\pm}19.1$, $5.7{\pm}8.9%$, respectively. Sperm motility of couples with penetration rates between on 15-30% and on 30> were $54.1{\pm}4.6$, $55.5{\pm}8.3%$ respectively. Hamster penetration rates of couples participating in an in vitro fertilization and embryo transfer program was $38.9{\pm}29.9%$. But in one case, a positive fertility assessment was obtained in the absence of fertilization of the wife's eggs attributable to egg immaturity. This method may have potential value as a diagnostic tool in evaluation human sperm fertilization capacity which avoids the ethical and logistical problems associated with fertilizing of human eggs in vitro.

• Clinical and Experimental Reproductive Medicine
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• 제18권1호
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• pp.81-87
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• 1991

There studies were carried for evaluation of the efficiency of freezing of hamster oocytes for use in a human sperm penetration assay. The hamster oocytes fully equilibrated in various cryoprotectant agents and inseminated with human sperm. After insemination with hamster oocytes, there was no difference in penetrated rates. Cumulus free oocytes equilibrated in 1.5M various cryoprotective agents and slowely cooled to temperature $-30^{\circ}C$ before rapid cooling and storage in nitrozen tank. After rapid thawing, survival rates of frozen oocytes according to cryo-protective agents were examined and the human sperm penetration assay with zona free hamster oocytes was conducted. 1. Survival rates of oocytes after cryoprotectants exposure have no significant difference (range 88-91%) and peneration rate was 51.1%. 2. Recovery and survival rate of frozen-thawed oocytes were 85.1 and 66.8%. There was no significant difference on cryoprotective agents. 3. Penetration rates of the frozen-thawed and intact oocytes were 69.0 and 77.0%, respectively. 4. Hamster oocytes cryopreservation provides a convenient way of supplying and trans-porting hamster oocytes for the assessment of the fertilizing potential of human spermatozoa.

• Clinical and Experimental Reproductive Medicine
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• 제28권1호
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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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권2호
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• pp.137-145
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• 2000

Carcinogenesis is a multi-stage process that generally consists of at least three steps; initiation, promotion, and progression. If one of these carcinogenic steps were suppressed or delayed, the cancer could be prevented. Cancer chemoprevention is defined to be inhibition or reversal of the carcinogenic process by the specific chemical agents and is a novel approach to cancer management alternative to conventional chemotherapy. Chlorophylln(CHL), a water-soluble derivative of chlorophyll, containing sodium and copper, has been known to be strong antimutagen in several test systems, but its mechanism of antimutagenic action is unknown. In the present experiment, the possibility of CHL as chemopreventive drugs on 7,12-dimethylbenz[a]anthracene(DMBA)-induced hamster buccal pouch carcinogenesis was investigated by mutagenicity test, carcinogenicity test, and frequency or spectrum of H-ras mutations in the both of DMBA-induced and chlorophylln-pretreated-DMBA induced tumor by polymerase chain reaction and non-isotopic restriction fragment length polymorphism. The treatment of CHL reduced the yields and multiplicity of the 0.5% DMBA-induced tumor, 86% to 62.5% and $3.7{\pm}0.6$ to $1.4{\pm}0.3$, respectively. The occurrence of histidine revertant by $20{\mu}mole$ DMBA was inhibited 25.6 to 81.7% by 1 to $5{\mu}M$ CHL in a dose-dependent manner. The mutation rates of H-ras gene in DMBA-induced and CHL-pretreated-DMBA induced tumor were 96%, 94% of which the most mutations were in codon 12/13. These results suggest that CHL inhibits the carcinogenic action of DMBA by the formation of complex between CHL and DMBA or the inhibition of the activation of DMBA in vivo. But CHL did not affect the mutation rates or its spectrum in already formed tumor.

• 대한의생명과학회지
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• 제3권1호
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• pp.1-9
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• 1997

대부분의 포유동물들에서 수정전에 정자의 첨체반응이 일어난다고 알려져 있으며 첨체반응에서 $Ca^{2+}$ 이 중요한 역할을 한다고 알려져 있다. 단백질 또한 정자의 생리적 역할에 중요한 요소로 작용한다고 보고되고 있다. 본 실험에서는 동면동물의 부정소에서 정자성숙과정을 비교 관찰하고 성숙 과정에 있어 $Ca^{2+}$ 농도와의 연관성을 규명하고 정자성숙 전, 후에 정자성숙에 영향을 미치는 $Mg^{2+}$-ATPase, lactate dehydrogenase의 작용을 비교, 분석하였다. 그 결과 다음과 같은 결과를 얻었다. 대표적 동면동물인 박쥐의 경우 활동기에 다른 동면동물인 햄스터, 항온동물인 생쥐와 마찬가지로 부정소미에서 정자성숙과정을 거쳤으며 교미시 대부분의 정자는 부정소미에서 더욱 활발한 운동성을 보였으며 부정소미 말에서 수정능획득 과정을 거치는 것으로 관찰되었다. 그러나 동면동물의 환경 조건 특히 온도의 변화가 부정소에서의 정자성숙과정에 영향을 주는지에 대해서는 더 자세한 연구가 필요하다고 사료된다.

• Applied Microscopy
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• 제27권2호
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• pp.177-187
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• 1997

Hydrocephalus is induced experimentally in prenatal and suckling animals following an injection of 6-aminonicotinamide (6-AN). The most remarkable characteristic of these animals is aqueduct stenosis caused by swellings of the ependymal cells and subependymal cells in the periaqueductal gray matter and the central canal of the spinal cord. The present study was undertaken to investigate the morphological changes of the ependymal cells in the central canal of the spinal cord of 3.5 months old hamster after treatment with 6-AN. Intraperitoneal administrations of 6-AN (10 mg/kg body weight) every two days gave rise to partial central canal stenosis of the spinal cord after 27-29 days (13-l4th injection), but cilia and microvilli were located in the strictural area of the con#rat canal. The vacuolations in the ependymal cells were not observed and degenerating changes of intracellular organelles of the ependymal cells did not occur, so that the ependymal cells lining the central canal of the hamster spinal cord were not affected by 6-AN. But the present study demonstrate that 6-AN causes to create numerous vacuoles in the subependymal area of the central canal. Although the vacuoles were well developed in the neuroglial cells and the neuropils of the subependymal area, the neurons were not affected by 6-AN. These results strongly suggests that partial central canal stenosis occurred by 6-AN was due to vacuolations and swellings of the neuroglial cells and nueropils in the subependymal area.

• 한국수의병리학회지
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• 제6권1호
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• pp.41-48
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• 2002

Oval cell is considered as facultative precursor cells for both hepatocytes and biliary cells, as well as origin of hepatocellar and cholangiocellular carcinoma (CCC) during carcinogenesis or toxic liver injury. To clarify the cellular origin or differentiation of cholagiocarcinogensis, the fate of carcinogen-induced oval cells was pathologically and phenotypically chased in Syrian golden hamster liver after Clonorchis sinensis (CS) infection which would give rise to a promoting effect. Two week treatment of hamsters with 0.005% diethylnitrosamine (DEN) followed by 2 week treatment of 1% 2-acetylaminofluorene (AAF) under choline deficient diet resulted in massive proliferation of BrdU labeleed and PCNA positive oval cells showing various distinct morphology, histochemical and immunohistochemical phenotypes for GGT, cytokeratin 19 and OV-6. Oval cells also frequently form ductular-like structures or phenotypically show hepatocyte-like characteristics. After CS infection, the oval cells showed sequential morphological changes to atypicl proliferating bile ductules and all hamsters thereafter developed well differentiated and anaplastic CCC at 16 week after CS infection. In electron microscopy, some bile ductules were constructed by intermediate oval cells and bile ductular cells surrounded by basement membrane. The results of this study strongly suggest that CCC developed in the present study were originated from hepatic stem-like oval cells, supporting the theory of stem cell origin of cancers. In addition, this hamster model would be valuable for the molecular mechanistic study during chemical-triggered cholangiocarcinogenesis.

• 대한수의학회지
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• 제34권1호
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• pp.127-134
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• 1994

As a series of studies to investigate the effect of immunosuppression on Ascaris suum infection in undefinitive hosts, a delicate relationship between host and parasite, in the present studies golden hamsters were alloted to experiment 1(normal undefinitive host group) and experiment 2(immunosuppressive group treated with prednisolone acetate) and inoculated with a single dose of 1,500 embryonated Ascaris suum eggs. The recovery rates, sizes and features of the larvae and immunological responses in the hamsters were chronologically monitored according to somatic migration. In both experiments, the larvae failed to develop into the adults, but the more and larger larvae were observed for a longer period from experiment 2 in comparison with experiment 1. The numbers of the mast cells in the small intestinal mucosa and mesenteric lymph nodes, of the goblet cells in the small intestinal mucosa and of T-cells in the mesenteric lymph nodes, spleens and cardiac blood from experiment 2 were fewer than those from the experiment 1. In general, increasing of these cells followed by expulsion of the worms in the both groups. Profound leukopenia due to lymphopenia was found through trial period in experiment 2. Considering the experimental results, development or expulsion mechanism of somatic migrant larvae may be related to lymphopenia and temporary increasing tendency of the mast cells, the goblet cells and T-cells. In addition, patent infection of A suum in the hamsters was not obviously observed in spite of immunosuppression by prednisolone acetate.

• 대한수의학회지
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• 제36권1호
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• pp.169-179
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• 1996

This study was carried out to examine the role of small cells and oval cells in cholangiocarcinogenesis in the hamsters infected with Clonorchis(C) sinensis. Forty two female Syrian golden hamsters were divided into two groups. Group I was for the induction of the cholangiocarcinoma, which was infected orally with C sinensis and given dimethylnitrosamine(15ppm) in drinking water for 4 weeks. Group II was served as control. More than 5 heads of hamsters in each group were sacrificed at 4, 7, 11 and 15 weeks after the beginning of the experiment. The livers were examined histopathologically, electron microscopically and immunohistochemically. The results obtained were as follows; 1. Cholangiocarcinomas were occurred in 1 of 6 animals at 11 weeks and in 4 of 6 animals at 15weeks after the beginning of the experiment. 2. Small cells and oval cells were proliferated around the portal triads from 4 weeks and peaked at 11 weeks, and slightly decreased after then. 3. The strong positive reaction to the $\alpha$-fetoprotein was shown in many of small cells and oval cells. But ductlike oval cells, which were arranged rosette form, showed week positive reaction to the $\alpha$-fetoprotein. 4. Most of small cells and oval cells showed negative reaction to the cytokeratin. But weak positive reaction in ductlike oval cells, and moderate positive reaction in cholangiocarcinoma cells were observed. These results suggested that cholangiocarcinoma induced by infection of C sinensis was believed to originate from the proliferated small cells around the portal triads which would be able to differentiate to the oval cells, ductlike oval cells, and cholangiocarcinoma cells gradually.

• 한국가축번식학회지
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• 제10권1호
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• pp.91-99
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• 1986

This experiment was undertaken to examine the effects of HIS treatment on the motility and acrosome reaction of frozen bovine spermatozoa and to test their abilities to interact with zona-free hamster eggs in vitro. Also, in vitro results were compared with those of bull's fertility in AI. The frozen semen from four Holstein bulls were exposed to HIS-DM for 5 minutes after thawing and then preincubated for 60 minutes in DM prior to insemination. The hamster eggs were mounted, fixed and stained 6 hours after exposure to boving spermatozoa and examined under a phase-contrast microscope. 1. The sperm motility expressed as a mobility index dro, pp.d significantly from 60-75 to 12-24 after exposure to HIS-DM, but increased in 32 to 41 at insemination. Bull C showed a low motility index than those of the orher bulls. The percentage of acrosome reaction by staining procedure were increased by HIS-DM treatment but did not change during 7 hours incubation period in DM. 2. The overall percentage of hamster eggs interacting with bull spermatozoa was 56.3%, 58.3%, 66.6% and 70.0%, respectively. Although there was no significant difference among bulls in the penetration rate of spermatozoa into hamster eggs, high proportions of eggs interacted with spermatozoa from Bull C and D than those from Bull A and B. 3. The conception rates (60-90 day RP) resulting from AI were 62.5%, 67.5% and 70.9% for Bull A, B and C, respectively. These results were in good agreement with the invitro results that the proportions of bull sperm-egg interction were greater for Bull C than for Bull A and B.