• The Korean Journal of Blood Transfusion
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• v.23 no.2
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• pp.115-126
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• 2012

Background: Umbilical cord (UC) is a promising source of mesenchymal stromal cells (MSCs). We compared the characteristics of MSCs from cryopreserved UC with those from fresh tissues, and demonstrated the possibility of UC cryopreservation for acquisition of MSCs from cryopreserved UC. Methods: Each UC was sliced into two types ($1{\sim}2mm^3$ vs. 0.5 cm), and cryopreserved in liquid nitrogen using different media (autologous cord blood plasma, aCBP vs. RPMI 1640). A fresh aliquot of $1{\sim}2mm^3$-sized UC was used as control tissue. After one week, the cryopreserved tissues were thawed and cultured. For the 0.5 cm UC, a slicing step into $1{\sim}2mm^3$ was needed. Cell count, viability, proliferative activity, and surface antigens were determined from harvested MSCs. Several growth factors (EGF, IGF-1, PDGF, TGF-${\beta}$, bFGF, and VEGF), were measured from the culture supernatant. Results: Eleven UC were enrolled in the study. Efficiencies of obtaining MSCs were higher in cryopreserved UC using RPMI 1640, compared with use of aCBP; the same result was observed for 0.5 cm sized UC, compared with $1{\sim}2mm^3$ sized UC. No difference in proliferative activity was observed between MSCs from fresh and cryopreserved UC. The amount of growth factors in culture supernatant using RPMI 1640 was larger than that of fresh tissues. Conclusion: We obtained growth factors from the supernatant as well as MSCs from cryopreserved UC. As with a cord blood bank, in the future, cryopreservation of UC for acquisition of both MSCs and growth factors would be possible in a time of need.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.83-83
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• 2003

돼지 난자의 유리화 동결 처리 방법 중 난자를 담는 용기(loading vessel)의 재료로 최근에 알려진 것으로 open-pulled straws(OPS)[Vajta등, Mol Reprod Dev, 51:53-58, (1998)], electron microscope grids(EMG) [Martino등,Biol Reprod, 54:1059-1069, (1996)〕, nylon loop system(NLS) [Lane등, Fertil Steril,72: 1073-1078, (1999)] 등이 보고되고 있다. OPS는 1/4cc straws를 열을 가하여 길게 뽑아 내벽을 얇게 함으로써 filing된 난자나 수정란이 액체 질소와 접촉했을 때 유리화가 신속하게 되도록 하는 방법으로 돼지에서는 별로 보고된 것이 없다. EMG는 열전도가 예민한 전자현미경용 copper grid를 이용한 방법으로 최근 국내 기술진의 연구성적을 포함한 몇몇 학자들에 의하여 보고되었고 NLS는 0.5mm직경의 nylon loop를 이용하여 급속 동결한 성적이 보고되었으나, 돼지 난자에 응용 된 것은 없다. 따라서 이와 같은 동결 재료는 사람과 반추류, mouse외에 돼지 난자에 대하여는 전혀 시도되지 않았지만 유리화 동결기술에서 가장 중요한 실험으로 생각된다. 성공적인 유리화 동결을 위해서는 수정란이 냉각의 전도성이 빠르고, 작은 용액을 수정란과 같이 filling해야 하며 모든 동작이 신속 간편해야 하며 융해 방법도 초급속도의 융해가 요구되므로 이에 부합되어야 한다. 연구 목적은 돼지 난자를 유리화 동결/융해 시 동결 재료-straw/glass, copper grid, nylon 3가지에 대한 제작 방법, 난자 loading, 동결 처리, 보관 방법, 융해 방법 등을 난자의 회수, 수정 후 생존율을 비교 조사하여 가장 우수한 방법을 선택할 목적이었다. 수행 내용은 3가지의 재료의 sample을 제작하고 소독한 다음 준비된 돼지 COCs을 40시간동안 IVM한 후 난자를 5~l5개 정도로 선정 하여 준비된 VS 용액에 평형처리 하였다. 각 재료의 용기에 loading 한 후 동결/보관하였고, 융해는 역순으로 평형하여 maturation 배지에 3~4시간 배양한 다음 경검하고 IVF한 후 NCSU-23 배지에 담아 IVC 배양하면서 cell cleavage상태를 확인하였다.

• KOREAN POULTRY JOURNAL
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• v.20 no.4 s.222
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• pp.116-118
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• 1988

마렉 질병은 1907년 오스트리아와 헝가리에서 처음 발견된 이래 닭이 밀사 사육되는 곳이라면 어디서든지 더욱 유행되어 가고 있다. 그렇지만 1970년대초 백신의 개발에 의하여 광범위한 지역에서 억제되어 가고 있다. HVT 백신이 가장 광범위하게 사용되고 있으며, 사용 가능한 HVT백신은 2가지 형태로 되어있다. 그 한가지는 액체질소안에 보관하고 운반되는 동결(Cell-Associated) 백신이며, 또 한가지는 냉장보관하여야 하는 냉동건조(Cell-free)백신이다.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.139-148
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• 2012

Purpose : Since standard solution is the one that knows its exact concentration, the curve of the dissolution has been determined according to the amount of the solution, compared to the amount of the unknown sample. Therefore, the antigen that makes up standard materials should be made in a pure form. The configuration of the standard substance solution in the kit we use is a freeze-dried material, or made and comes as a liquid. Lyophilized reference material is used after dissolving in usually D.W. (Distilled Water), and if the antigen to use is too sensitive, reagents should be freeze-dried. Furthermore, when freeze-dried reference has to be frozen again after being dissolved, it should be kept under $-20^{\circ}C$ until the expiration date according to the reports. Since it is not expressed in the experiment if it is safe or stable to reuse the solution which was dissolved a few times, thus, this time it is tested and evaluated that the changes of the standard solution by freezing and melting several times, and its results and the effectiveness of it were compared to the solution which was kept in a fridge. Materials and Methods : Among Vitro diagnostic kits on the market made by radioimmunoassay, parathyroid hormone (PTH), adrenocorticotropic hormone (ACTH), luteinizing hormone (LH) are made of freeze-dried standard solution and all composed of the same Lot.NO. These hormones melted in D.W. and were separated into three groups. In the first group, melting and freezing were repeated, and in the second group, The solution only for one time use was put into a test tube after melting and freeze it. The third group was kept in the refrigerator. This experiment has been conducted from January to February in 2012. January to 2012. PH test was employed because ph is prone to changing depending on the change of protein. Each group of the standard solution, cpm (counter per minute), and the patient relative concentration values were compared by date, and Through the correlation coefficient and Paired t-test, the significant level of each group was analyzed. Results : ACTH, PTH, LH pH values were too subtle denaturation rather than numerical changes in the protein. In addition, when the standard solution of ACTH, PTH, LH was refrigerated, after 3 days and 7 days, there was a significant difference observed between the solution being kept in a refrigerator and a freezer within a significance level. Conclusion : Standard solution should be kept in a freezer, and being kept in a fridge, it is recommended to use the solution as soon as possible.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.3
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• pp.209-217
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• 2009

Objective: To analyze current issues and to propose alternatives for "the cryopreserved embryos generated before 2005". Methods: The differences in attitude among the stakeholders such as sperm donors, oocyte donors, and IVF clinics were presupposed. We want to forecast the impediments which occur inevitably in the process of "getting the informed consent" and "discarding the cryopreserved embryos generated before 2005". Results: Even though there is a specific guideline for "the cryopreserved embryos generated before 2005" at November 23, 2006, no consensus about the process related to "getting the informed consent" has been made. Conclusion: Unavoidably, it seems to be entering a period of massive discard of "the cryopreserved embryos generated before 2005". This is actually opposed to the intent of the Bioethics and Safety Act, which is to protect human dignity and prevent harm to human beings. We have to make reasonable due process to determine the destiny of "the cryopreserved embryos generated before 2005".

• Clinical and Experimental Reproductive Medicine
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• v.37 no.4
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• pp.329-338
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• 2010

Objective: This study was carried out to know whether cryopreservation of sibling 2PN zygotes could increase the cumulative delivery rates in the patients who had less than 10 fertilized zygotes. Methods: A retrospective analysis was performed in 138 in vitro fertilization-embryo transfer (IVF-ET) cycles with less than 10 fertilized zygotes during January 2003 to December 2007 in Cheil General Hospital. These cycles were divided into two groups. In Group I (n=86), all fertilized embryos were cultured to transfer on day 3 without cryopreserved embryos at the 2PN stage. In Group II (n=52), among fertilized zygotes, some sibling zygotes were frozen at the 2PN stage, the remainder were cultured to transfer. Clinical outcomes in fresh ET cycles and cumulative ongoing pregnancy rates after subsequent frozen-thawed (FT)-ET cycles were compared. Results: There were no significant differences in female mean age, number of retrieved oocytes and total fertilized embryos between two groups, Number of cultured embryos was significantly lower in Group II ($5.2{\pm}0.5$) than in Group I ($8.4{\pm}0.7$) (p<0.01). Also, number of transferred embryos was significantly lower in Group II ($3.3{\pm}0.6$) compared with Group I ($3.6{\pm}0.6$) (p<0.01). ${\beta}$-hCG positive rates and delivery rates (51.2 vs. 46.2 % and 41.9 vs. 34.6 %, respectively) after fresh ET were slightly higher in Group I than in Group II. However, the differences were not statistically significant. Also, the cumulative delivery rates after subsequent FT-ET cycles were not significantly different between Group I (48.8%) and Group II (50.0%). Conclusion: This study showed that cryopreservation of sibling 2PN zygotes from patients who had less than 10 zygotes in the fresh ET cycles did not increase cumulative delivery outcomes. But, it could provide an alternative choice for patients due to offering more chance for embryo transfers if pregnancy was failed in fresh IVF-ET cycles.

• Journal of Oral Medicine and Pain
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• v.31 no.1
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• pp.1-16
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• 2006

The most important progress in diagnostic sciences is the increased sensitivity and specificity in diagnostic procedures due to the development of micromethodologies and increasing availability of immunological and molecular biological reagents. The technological advances led to consider the diagnostic use of saliva for an array of analytes and DNA source. The purpose of the present study was to compare DNA from saliva with those from blood and buccal swab, to evaluate diagnostic and forensic application of saliva, to investigate the changes of genomic DNA in saliva according to the storage temperature and period of saliva samples, and to evaluate the integrity of the DNA from saliva stored under various storage conditions by PCR analysis. Peripheral venous blood, unstimulated whole saliva, stimulated whole saliva, and buccal swab were obtained from healthy 10 subjects (mean age: $29.9{\pm}9.8$ years) and genomic DNA was extracted using commercial kit. For the study of effects of various storage conditions on genomic DNA from saliva, stimulated whole saliva were obtained from healthy 20 subjects (mean age: $32.3{\pm}6.6$ years). After making aliquots from fresh saliva, they were stored at room temperature, $4^{\circ}C$, $-20^{\circ}C$, and $-70^{\circ}C$. Saliva samples after lyophilization and dry-out procedure were stored at room temperature. After 1, 3, and 5 months, the same experiment was performed to investigate the changes in genomic DNA in saliva samples. In case of saliva aliquots stored at room temperature and dry-out samples, the results in 2 weeks were also included. Integrity of DNA from saliva stored under various storage conditions was also evaluated by PCR amplification analysis of $\beta$-globin gene fragments (989-bp). The results were as follows: 1. Concentration of genomic DNA extracted from saliva was lower than that from blood (p<0.05), but there were no significant differences among various types of saliva samples. Purities of genomic DNA extracted from stimulated whole saliva and lyophilized one were significantly higher than that from blood (p<0.05). Purity of genomic DNA extracted from buccal swab was lower than those from various types of saliva samples (p<0.05). 2. Concentration of genomic DNA from saliva stored at room temperature showed gradual reduction after 1 month, and decreased significantly in 3 and 5 months (p<0.05, p<0.01, respectively). Purities of DNA from saliva stored for 3 and 5 months showed significant differences with those of fresh saliva and stored saliva for 1 month (p<0.05). 3. In the case of saliva stored at $4^{\circ}C$ and $-20^{\circ}C$, there were no significant changes of concentration of genomic DNA in 3 months. Concentration of DNA decreased significantly in 5 months (p<0.05). 4. There were no significant differences of concentration of genomic DNA from saliva stored at $-70^{\circ}C$ and from lyophilized one according to storage period. Concentration of DNA showed decreasing tendency in 5 months. 5. Concentration of genomic DNA immediately extracted from saliva dried on Petri dish were 60% compared with that of fresh saliva. Concentration of DNA from saliva stored at room temperature after dry-out showed rapid reduction within 2 weeks (p<0.05). 6. Amplification of $\beta$-globin gene using PCR was successful in all lyophilized saliva stored for 5 months. At the time of 1 month, $\beta$-globin gene was successfully amplified in all saliva samples stored at $-20^{\circ}C$ and $-70^{\circ}C$, and in some saliva samples stored at $4^{\circ}C$. $\beta$-globin gene was failed to amplify in saliva stored at room temperature and dry-out saliva.

• Journal of Dairy Science and Biotechnology
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• v.37 no.3
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• pp.206-212
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• 2019

This study was conducted to investigate the effect of cryoprotectants on the storage stability of Lactobacillus fermentum SK152, which was isolated as a probiotic candidate. Solutions of 10% glucose, trehalose, dextrin, and skim milk powder were used as cryoprotectants. The survival rates of L. fermentum SK152 after freeze-drying were 5.6% (dextrin), 2.2% (skim milk powder), 1.7% (glucose), and 1.5% (trehalose), suggesting that dextrin was most effective at minimizing the cell death of L. fermentum SK152 by lyophilization. The survival rates of L. fermentum SK152 stored at 4℃ ranged from 37% (dextrin)-90% (skim milk powder) after 8 weeks, while those at 20℃ ranged from 4% (dextrin)-12% (skim milk powder) after 7 weeks, indicating that skim milk powder was the best at minimizing the cell death of L. fermentum SK152 during storage, irrespective of storage temperature, among the cryoprotectants used.

• Korean Journal Plant Pathology
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• v.2 no.3
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• pp.150-157
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• 1986

Effects of presservation methods on viability and virulence of Xanthosmonas compestris pv. oryzae were investigated. The incidence of colony-type variants from freeze-dried and deep-frozen cultures was also determined. The suspending medium for freeze-dried cultures containing $10\%$ sucrose and $1\%$ gelatin showed the highest viability, and the virulence was well maintained in the suspending medium containing $2\%$ dextrin, $0.5\%$ ascorbic acid, 0.5% ammonium chloride, $0.5\%$ thiourea, and $0.85\%$ NaCl. Serially transferred cultures became attenuated. Rough colonies which had wrinkled surface occurred at a frequency of $1.9\%$ to $15.8\%$ during freeze-drying and freezing. The rough colonies consisted of nonseptated filamentous cells and rod-shaped cells. The virulence of rough colonies was weak as compared with the normal colony type.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.29 no.7
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• pp.28-35
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• 2000

LNG 냉열 이용은 일본초저온(주)의 냉장보관 사업의 에너지절감 (65%)형 초저온 (-55$^{\circ}C$) 대형냉장고로 일본 뿐만 아니라 세계적으로 최초의 냉장업체이다. 회사 건설시는 입지선정, 경제성검토, 기술성, 공해상의 검토 등을 거쳐 완성된 업체로써 시설규모는 냉장 20,000 M/T, 1일 LNG 공급량 90M/T으로 현재 가동중이며 대부분의 동결 및 냉장 품목은 참치(마구로)가 83%를 차지하고 기타가 17% 였다. 냉장고의 가동율은 75%로 매우 높은 편이였다, LNG식 냉동장치의 가장 큰 장점은 일반적인 냉동방식 전력비의 1/3 밖에 소요되지 않는다는 것이다. L$N_2$의 내열이용 업체는 근기냉열(주)은 오사카의 천북에 있으며, L$N_2$를 자가 생산하여 면류 생산공장으로 직송하고 동결제조 하여 품질의 고급화 및 위생식품을 제조 판매하고 있다. 규모는 년간 2,000만식을 생산하고 주 생산제품은 조리면 및 냉동우동 등이다. L$N_2$의 소비가격은 전기식 냉동기에 비하여 5~9배의 고액이 소요되는 것이 결점이라고 할 수 있다.