• 한국식품영양학회지
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• 제12권4호
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• pp.370-374
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• 1999

This study was carried out to some properties and curring effect of drip obtained from frozen-thawed park loin ham belly and imported belly by thawing process at 4$^{\circ}C$. Moisture content and pH value of drips were 88.05~90.85% and 5,72~6.05 and do not show significant differences between each samples. Protein contents were 11.07, 8.85, 8,76 and8,13% in the drips from domestic pork loin, ham, belly and imported belly, respectively. Approximately 99% of the drip were constituted with moisture and protein in any part of domestic pork and imported belly. Glutamic acid proline glycine, alanine and lysine were the predominant amino acid in the drips. Curing process of the drip by nitrite increased the pH value and total amino acid content. The residual nitrite decreased during the period of curing and total plate counts in drip with nitrite did not reach 1$\times$105CFU/g until 7 days.

• 한국가축번식학회지
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• 제9권1호
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• pp.36-39
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• 1985

This experiment was carried out to investigate the morphology of bovine embryos thawed after deep freezing at -196$^{\circ}C$ and the development of frozen-thawed embryos after in vitro culture in Ham's F-10 medium with 10% NBCS. The results obtained were summarized as follows: 1. The propotion of embryos which a, pp.ared mophologically normal was averaged 77.5% (79/102). 2. The morphologically normal rate of frozen-thawed blastocyst (78.6%) was higher than that of morula (76.7%), but there was no significant difference. 3. Normal development was observed in 20 of 68 embryos cultured for 24-72hr in medium and overall survival rate was 29.4%. 4. Survival rate fo blastocyst (33.3%) was higher than that of morula (25.7%).

• 동아시아식생활학회지
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• 제23권4호
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• pp.487-495
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• 2013

돼지고기의 저지방 부위인 뒷다리살과 등심을 진공포장하여 $-20^{\circ}C$에서 3개월간 동결한 후 해동하였다. 해동육을 $3^{\circ}C$에 냉장하면서 냉장기간에 따른 생육과 가열육의 물리적 특성 변화를 확인하였다. 생육의 경우, 뒷다리살은 해동직후(냉장 0일)에 비하여 냉장 4일에 pH 값, $L^*$값, 드립 감량, 보수력, 점성이 상승한 반면, 가열감량, 경도 및 저작성은 유의적으로 낮아지는 현상을 보였다(p<0.05). 등심은 해동 후 냉장 2일에 이와 같은 같은 현상이 나타났다. 가열육의 물리적 특성 변화는 두 부위 모두 생육의 경우와 비슷한 경향을 보였으나, pH 값, $L^*$값 및 $a^*$값은 해동 후 냉장 중 유의적 차이를 보이지 않았다. 생육과 가열육의 탄력성 및 응집성은 두부위 모두 해동 후 냉장 중에 유의적 차이를 나타내지 않았다. 뒷다리살과 등심은 각각 해동 후 냉장 4일과 2일에 연도가 유의적으로 향상되었다(p<0.05).

• 한국수정란이식학회지
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• 제10권3호
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• pp.203-208
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• 1995

This study was carried out to efficiently use the ultrarapid freezing method in the cryopreservation of mouse ova. For this, the effects of dehydration method, oval vigour and $0^{\circ}C$ controlling method on post-thawing viability were investigated. Fresh mouse ova were dehydrated in mPBS with 3.5M DMSO and /or 0.25M sucrose, and directly immersed in L$N_2$ for ultrarapidly freezing. The frozen ova were thawed at 37$^{\circ}C$, rehydrated in mPBS with 0.25M sucrose, and then repeatedly washed in HAM's Fl0 before evaluating the morphological normality of frozen-thawed ova. The results obtained showed that there was difference between treatments in a experiment. 1) The post-thawing viability of ova dehydrated in multi-step (48.4$\pm$13.8%) was higher than that of ova in two-step (40.9$\pm$14.0%). 2) The post-thawing viability of fertilized ova (87$\pm$14.0%) was significantly(p<0.0l) higher than that of unfertilized ova (5.4$\pm$5.4%). 3) The post-thawing viability of ova dehydrated and rehydrated using a cooling machine (95.8$\pm$4.2%) was significantly(p<0.05) higher than that on ice(84.1$\pm$9.9). In conclusion, in order to efficiently cryopreserve ova in vitro with ultrarapidly freezing method, highly viable embryos should be selected, heavy osmotic shock to the dehydrating ova should be avoided, and embryos in high osmotic condition were dehydrated and rehydrated in a constantly low temperature.

• 한국축산식품학회지
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• 제34권5호
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• pp.597-603
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• 2014

In this study, the physicochemical and sensory quality characteristics due to the influence of various thawing methods on electro-magnetic and air blast frozen pork were examined. The packaged pork samples, which were frozen by air blast freezing at $-45^{\circ}C$ or electro-magnetic freezing at $-55^{\circ}C$, were thawed using 4 different methods: refrigeration ($4{\pm}1^{\circ}C$), room temperature (RT, $25^{\circ}C$), cold water ($15^{\circ}C$), and microwave (2450 MHz). Analyses were carried out to determine the drip and cooking loss, water holding capacity (WHC), moisture content and sensory evaluation. Frozen pork thawed in a microwave indicated relatively less thawing loss (0.63-1.24%) than the other thawing methods (0.68-1.38%). The cooking loss after electro-magnetic freezing indicated 37.4% by microwave thawing, compared with 32.9% by refrigeration, 36.5% by RT, and 37.2% by cold water in ham. The thawing of samples frozen by electro-magnetic freezing showed no significant differences between the methods used, while the moisture content was higher in belly thawed by microwave (62.0%) after electro-magnetic freezing than refrigeration (54.8%), RT (61.3%), and cold water (61.1%). The highest overall acceptability was shown for microwave thawing after electro-magnetic freezing but there were no significant differences compared to that of the other samples.

• Clinical and Experimental Reproductive Medicine
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• 제42권4호
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• pp.175-180
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• 2015

Objective: Embryo loading (EL) is a major step in embryo transfer (ET) and affect on the success of in vitro fertilization (IVF). This study aimed to compare the effect of two different EL techniques on the rates of pregnancy and delivery in IVF/ET cycles. Methods: 207 fresh ET and 194 Frozen-thawed ET (FET) cycles were included in this retrospective study. Two groups (A and B) were defined based on the EL technique used. In group A, the entire catheter was flushed with Ham's F-10 medium. The embryos were then drawn into the catheter using one air bracket. In group B, $70{\mu}L$ of air was aspirated into the syringe and the catheter was flushed using Ham's F10 medium. The medium, air, embryos, air, and finally another layer of medium were then sequentially drawn into the catheter. The main outcome measures were the pregnancy and delivery rates. Results: The groups did not differ with respect to the etiology of infertility, the source of spermatozoa, the quality of the embryos, the type of EL catheter, and the ease of transfer. The pregnancy rate was similar between two groups. In fresh ET cycles, a higher delivery rate was observed in group B than it group A (78.1% vs. 60%, p=0.1). In FET cycles, the rate of delivery was significantly higher in group B than in group A to a nonsignificant extent (88.9% vs. 58.8%, p=0.06). Conclusion: EL techniques did not have a significant impact on the delivery rate in either fresh or FET cycles.

• Clinical and Experimental Reproductive Medicine
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• 제27권4호
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• pp.345-351
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• 2000

Objective: Hatching of the blastocyst from the zona pellucida (ZP) is a key event in mammalian implantation. In vivo, two factors have been identified as possible mediators of hatching: lysis of the ZP by substances elaborated either from the embryo or female reproductive tract and pressure exerted on the zona by expansion of the blastocyst. Two methods of zona manipulation were already in use to enhance the ability of embryos to hatch: mechanical PZD and chemical ZD by acidic Tyrode's solution. But several controversies of each method have been reported. The purpose of this study was to investigate the effect of pronase for mouse embryo hatching. Methods: Mouse embryos were obtained following ovulation induction of $F_1$ animals. Fresh and cryo-thawed morula embryos were exposed to 0.5, 1.0, 2.0, 5.0 ${\mu}g/ml$ pronase in Ham's F10 for 72 hrs. Main outcome measures were the rates of partial hatching and completely hatched blastocysts, and cell number of it. Results: In fresh and cryo-thawed group, the rates of completely hatched blastocyst were significantly higher in 5 ${\mu}g/ml$ pronase treatment group than control group. There was no difference in completely hatched blastocyst total cell number between pronase treatment group and control group. This suggest that pronase treatment did not harmful in mouse embryo development. In pronase treatment group, zona pellucida were thinner than control group. Conclusion: The addition of pronase to culture media may accelerate the hatching of embryo. So, enzymatic treatment of the zona may provide a valuable and effective assisted hatching technique for human in-vitro fertilization-embryo transfer.

• Clinical and Experimental Reproductive Medicine
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• 제21권3호
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• pp.315-323
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• 1994

Mammalian oviductal epithelial cells have been known to improve in vitro fertilization and embryonic development. Recently, co-cultured human embryos with the epithelial cells in human genital tract has been reported to improve the pregnancy rate. The purpose of the study was to investigate the effects of the epithelial cells of human genital tract on the development of mouse early embryos and human fertilized oocytes. The epithelial cells of human genital tract were collected from the fallopian tubes which were obtained during hysterectomy in fertile women and from the endometrium during endometrium biopsy. Collected human ampullary cells(HACs) and endometrial cells(HECs) were cultured for 10 days to establish primary monolayer. Second passaged HACs and HECs were obtained by trypsinization were cryopreserved in PBS with 1.5 M DMSO for later use. To investigate the effect when co-cultured with HACs and HECs, we tried to apply strict quality control on mouse embryo, from two cell to blastocyst prior to human trial. The results of quality control were as follows; In Group I (Ham's F10 with 10% FCS), Group IT (co-cultured with HACs) and Group ill (co-cultured with HECs), developmental rates to blastocyst were 63.3%(253/400), 76.0%(304/ 400),74.0%(296/400), respectively. Hatching rates were 36.8%(147/400), 41.80/0(167/400), 38.0%(152/400), respectively(p<0.05). To perform the human IVF, cryopreserved HACs were thawed at 37$^{\circ}C$ waterbath, seeded on the well dish and cultured for 48 hI'S. The pronuclear stage embryos were transferred to the seeded well dish. After 24 hRS, co-cultured embryos were examined and transferred to patient's uterus. The results of human IVF when co-cultured with HACs were that fertilization and developmental rates were 61.8% (256/414), 95.3% (244/256) as compared with 57.2% (279/488) and 94.6%(264/279) in Ham's F10 supplemented with 10% FCS(control). However, 62.9% (161/256) of co-cultured human embryos showed good embryos(no or slight fragmentation) as compared with 53.8 % (150/279) in control(p < 0.05). Pregnancy rate was 40.0% (12/30) when co-cultured with HACs whereas 30.6%(11/36) in control. In conclusions, co-culture system using HACs and HECs improved the developmental and hatching rates of mouse embryo. Also, in human IVF system when co-cultured with HACs, it improved both the quality of human embryos and the pregnancy rate.

• 한국미생물·생명공학회지
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• 제24권1호
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• pp.126-131
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• 1996

HL-60 was cultivated to produce tPA (tissue-type plasminogen activator) and study the mechanism of cell death. Maximum cell density and tPA production were obtained as $5.27{\times}10^6$ cells/ml and 324ng/ml, respectively under perfusion cultivation. tPA production was enhanced to 420ng/ml in adding 160nM of phorbol ester. The cells were gradually differentiated to granulocytes rather than proliferation. By Fluorescent microscope, apoptosis was prevailed except the death phase and in high agitation speed, but necrosis was prevailed in thawed cells and during the latter periods of the cultivation. It was also proved that tPA was most produced in apoptosis. To obtain higher tPA productivity, the cells must be maintained in apoptosis, not necrosis phase when the cells were dying.

• 생명과학회지
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• 제30권1호
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• pp.77-81
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• 2020

본 연구는 돼지정자의 동결보존에 있어 0.5 ml straw에 비해 5.0 ml straw가 가지고 있었던 제한적인 요소들을 극복하기 위하여 동결속도, 융해온도 및 융해 시간을 확립하기 위하여 실시되었다. 동결속도는 정자가 -140℃까지 도달하는 시간을 8분 30초인 동결법(FR-1)과 14분인 동결법(FR-2)으로 나누어 각각 0.5 ml 및 5 ml straw를 이용하여 동결하였으며, 동결-융해한 정자는 CASA 장비를 이용하여 정자 성상을 비교 분석하였다. 동결속도 만큼 융해 온도 및 시간 또한 매우 중요한 요소이기 때문에 융해 방법을 37℃, 50℃ 및 70℃에서 각각 115초, 45초 및 25초간 실시하여 정자 성상을 비교하였다. 그 결과 FR-2의 동결속도 보다 FR-1의 동결속도에서 높은 생존율과 운동성을 보였고, 50℃에서 45초간 융해 하였을 때 가장 높은 생존율과 운동성을 보였다(73.4±3.6; 74.5±2.2%, p<0.05). 정자의 첨체 충실성 및 형태학적 특징에서는 처리구간에 유의적인 차이가 없었다. 본 연구를 통해 얻은 데이터를 종합해볼 때, 그 동안 동결정액을 이용한 돼지 인공수정 시 5.0 ml straw가 0.5 ml straw 비해 저조한 정자 생존율 및 활력을 나타냄으로써 번식성적이 떨어져 사용을 기피하여 왔지만 개선된 프로토콜을 활용하면 동결정액을 이용한 돼지 인공수정에 있어 여러 straw를 융해해야 하는 불편함 대신에 인공수정 시 1 straw를(dose) 융해하여 사용함으로써 사용자의 편리성을 높일 뿐만 아니라 인공수정에 있어 집중력을 높여 번식성적 향상에도 기여할 것으로 사료된다.