• Journal of Chest Surgery
• /
• v.33 no.12
• /
• pp.929-934
• /
• 2000

배경: 기관의 동종이식편은 초냉동보관으로 생육성을 유지할 수 있으며 항원성이 줄어든다고 알려졌으나 냉동보관 온도 및 기간에 따른 항원성의 변화는 아직까지 명확히 밝혀져 있지 않다. 따라서 이번 연구에서는 냉동보관 온도의 차이 및 기간이 쥐 기관 동종이식편의 거부반응에 미치는 영향을 연구하였다. 대상 및 방법: 24개의 쥐 기관을 적출하여 12개씩 -8$0^{\circ}C$ 냉동고 및 -196$^{\circ}C$ 질소탱크에 각각 1, 3, 6개월씩 보관하였다. 냉동보관한 기관을 반으로 나누어 48마리의 쥐복강에 대망으로 감싼 다음 이식하였다. 1, 3, 5군은 -8$0^{\circ}C$ 냉동고에 각각 1, 3, 6개월씩 보관한 기관 동종이식편을 이식하였고 2, 4, 6군은 -196$^{\circ}C$ 질소탱크에 각각 1, 3, 6개월씩 보관한 기관 동종이식편을 이식하였다. 7군은 대조군으로 냉동보관하지 않은 동종이식편을 이식하였다. 이식후 14일째 이식된 동종이식편을 적출하여 간질조직의 단세포 침윤정도 및 내강 폐쇄 정도를 관찰하여 거부반응을 정도를 측정하였다. 결과: 7개 군 모두에서 중등도 이상의 심한 단세포 침윤을 보였으며 각군간의 통계학적인 차이를 보이지 않았다. 1, 2, 3, 4, 5, 6군에서 7군에서 보다 내강 폐쇄 정도가 적었으나 통계학적인 의의는 없었다. 모든 군에서 연골주위 단세포 침윤이 심한 경우에도 연골세포는 비교적 생육성을 잘 유지하고 있었다. 결론: 냉동보관 온도 및 보관 기간의 차이에 따른 동종이식편의 거부반응의 차이는 없었으며 모든 군에서 심한 거부반응을 보였다. 따라서 냉동 보관 쥐 동종이식편을 이용한 실험에서는 적절한 면역억제제의 사용이 필수적이라고 생각된다.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.2
• /
• pp.239-245
• /
• 2012

This study was performed to evaluate the quality characteristics of Sulgi (Korean steamed rice cakes) prepared with fresh or frozen red onions. Sulgi was prepared with different levels (10, 20 or 30%) of fresh or frozen onions and stored for 4 days. The L value significantly decreased with the addition of fresh red onions and the a value significantly increased with the addition of either fresh or frozen red onions. The pH value was also increased with the addition of fresh red onions. In terms of texture, the hardness of Sulgi with either fresh or frozen red onions was reduced. The gumminess and brittleness gradually decreased with the addition of fresh or frozen red onions. Sulgi composed of 30% red onions showed the best sensory results in terms of color, flavor, texture, taste, and overall acceptance.

• The Korean Journal of Food And Nutrition
• /
• v.13 no.5
• /
• pp.403-410
• /
• 2000

This study was carried out to understand the effect of addition of potato search on the frozen dough. The characteristics of frozen dough were measured by the farinogram, the extensogram and the amylogram. The results of these measurements show that the dough added with starch has higher stability than the control. The physical and chemical change of the dough were measured in accordance with the period of the frozen storage. The dough added with starch showed smaller physical and chemical change than control, which means that the starch prevents the frozen dough from the deterioration during the frozen storage. It is supposed from this result that the starch protects the activity of yeast and the structure of gluten matrices from frozen damage. It is understood from this study that addition of potato starch into frozen dough improve the stability of the frozen dough.

• Parasites, Hosts and Diseases
• /
• v.30 no.2
• /
• pp.151-153
• /
• 1992

We have successfully cryopreserved free-living amoebae in order to maintain them feasibly under the conditions in our laboratory. The viability of trophozoites was higher when frozen by slow cooling (overall $0.7^{\circ}C$/min) than by fast cooling (overall $1.3^{\circ}C$/min). Glycerol and dimethylsulfoxide at the final concentration of 7.5% each was used for cryopreservation of free-living amoebae trophosoites. The survival rate was 2∼39% after storage in the liquid nitrogen for 60 days. Gross cultural or morphological changes were not noted in trophozoites thawed from frozen suspensions.

• Food Science and Preservation
• /
• v.16 no.6
• /
• pp.824-829
• /
• 2009

Changes in pH, viable microbial count, chemical freshness, texture, and sensory qualities of Sing Sing Hoe (SSH, fresh-sliced raw fish) were measured over 15 days at $4^{\circ}C$, $-20^{\circ}C$, and $-80^{\circ}C$. The initial pH of SSH was 6.25 at all three storage temperatures, and pH increased slightly after 12 days to pH 6.48 and pH 6.55 at $-20^{\circ}C$ and $-80^{\circ}C$, respectively. The range in viable cell count was 104-106 CFU/g, regardless of storage temperature. The initial content of volatile basic nitrogen (VBN) was 5.8 mg/100 g and became 8.2 mg/100 g or less, and 7.9 mg/100 g or less after 15 days at $-20^{\circ}C$ and $-80^{\circ}C$, respectively. However, pH and VBN values increased significantly after 3 days of storage at $4^{\circ}C$. At this temperature, the K-value was 22.3% after 6 days and 40% or more after 15 days. At $-20^{\circ}C$, the K-value was 9.6% or less after 6 days and 21% or less after 15 days of storage. At $-80^{\circ}C$, the K-value was 8.5% or less after 9 days and 20% or less after 15 days of storage. Compared with the K-value of live fish muscle (10%), freshness similar to that of live fish was maintained for 6 days under both $-20^{\circ}C$ and $-80^{\circ}C$ storage conditions. There was no significant change in texture during storage of SSH at $-20^{\circ}C$ or $-80^{\circ}C$, but SSH stored at $4^{\circ}C$ showed a decrease in texture quality during storage. Sensory scores were high for material stored for up to 3 days at $4^{\circ}C$ and 6 days at $-20^{\circ}C$ or $-80^{\circ}C$. The overall freshness of SSH was maintained for up to 6 days, in comparison with fresh-sliced raw fish, under both frozen storage conditions.

• Journal of Genetic Medicine
• /
• v.5 no.1
• /
• pp.55-60
• /
• 2008

Purpose : The ability to perform chromosome analysis of cryopreserved cord blood mononuclear cells is important for future retrospective studies. We compared the karyotypes of cryopreserved cells with cells before cryopreservation. Methods : One cord blood (CB) sample was obtained from normal healthy volunteer. Karyotype analysis was performed before cryopreservation. After mononuclear cell separation with Ficoll-Hypaque, the mononuclear cells were cryopreserved by programmed controlled-rate freezer and then transferred into the liquid nitrogen ($-196^{\circ}C$) for 3 days. After rapid thawing, cytogenetic analysis was performed as the same method for each sample by different conditions. The samples were divided by three groups. The first group was no culture before cryopreservation, the second group was 72 hours culture before cryopreservation, but no 24 hours culture after thawing and the third group was 72 hours culture before cryopreservation and 24 hours culture after thawing. Results : The chromosome analysis was successful in the second and third groups of CB sample. Conclusion : The successful result from CB samples may suggest the usefulness of long-term cryopreservation for retrospective study in various clinical settings including hematologic malignancies.

• Restorative Dentistry and Endodontics
• /
• v.34 no.4
• /
• pp.356-363
• /
• 2009

The purpose of this study was to evaluate the viability of periodontal ligament cells in rat teeth using slow cryo-preservation method under pressure by means of MTT assay and WST-1 assay. Eighteen teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both sides of the first and second maxillary molars were extracted as atraumatically as possible under Tiletamine anesthesia. The experimental groups were group 1 (Immediate control), group 2 (Cold preservation at $4^{\circ}C$for 1 week), group 3 (Slow freezing), group 4 (Slow freezing under pressure of 3 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in $37^{\circ}C$water bath, then MTT assay and WST-1 assay were processed. One way ANOVA and Tukey method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 4 showed significantly higher viability of periodontal ligament cells than group 2 and 3 (p < 0.05), but showed lower viability than immediate control group. By the results of this study, slow cryo-preservation method under pressure suggests the possibility for long term cryo-preservation of the teeth.

• Journal of Food Hygiene and Safety
• /
• v.38 no.5
• /
• pp.373-380
• /
• 2023

This study surveyed and compared the temperature distribution in domestic refrigerators and freezers used in Korea to determine whether temperature varied according to the location of food storage. We selected 50 people to collect temperature data; among them, 25 measured the temperature of refrigerators, while the remaining measured the temperature of freezers. Consequently, the lowest and highest temperatures measured in domestic refrigerators were found to be -8.2℃ and 15.8℃, respectively, with an average temperature of 3.73℃. The temperature distribution based on internal location was: 5.06±1.69℃ for the door storage compartment, 4.18±1.19℃ for the inside wall surface, and 3.41±1.36℃ for the inner storage box. Significant temperature differences between the top and bottom were only identified at the door storage compartment (P<0.01). Further, the minimum and maximum temperatures measured in the freezer was -30.3℃ and 0.7℃, respectively, with an average temperature of -17.95℃. The temperature distribution based on location was: -17.19±1.68℃ for the door storage compartment, -17.81±1.07℃ for the inside wall surface, and -18.78±1.72℃ for the inside storage box. The results were similar to that of the refrigerator, with the lowest temperature in the inside storage box, and a significant temperature difference between the top and bottom noted only at the door (P<0.01). The maximum temperature difference (between locations) within the refrigerator and freezer was found to be 2.18 and 2.02℃, respectively. In conclusion, the temperature in the entire space was not constant; there were significant deviations at different storage locations. Therefore, public authorities should actively advise customers on the recommended storage locations for each food type. People will benefit from awareness about storage management, including avoiding storage of temperature-sensitive foods in door compartment.

• Clinical and Experimental Reproductive Medicine
• /
• v.34 no.4
• /
• pp.253-273
• /
• 2007

Objective: This study was to find ways to let a manager or superintendent rationally and consistently inspect as well as let a embryologist precisely record [The Book of Supernumerary Embryo Preservation] and [The Book of Supernumerary Embryo Donation]. Methods: Based on the data collected between 1994 and 2004 in Clinic 44 (Maria Fertility Hospital), [The Present State about Production and Use of Embryos], [The Preservation of Supernumerary Embryos and Their Thaw State], [The Present State about Thaw and Use of Frozen Embryos], [The Present State about Donation and Charge of Frozen Embryos], [The Book about Frozen Embryo Discard], and [The Summarization Book about Management and Use of Frozen Embryos] were designed and recorded. Results: The production, use, preservation, discard and donation quantity of human embryos, the use and discard quantity of thawed embryos, and the cumulative embryo preservation quantity could be totalized in [The Present State about Production and Use of Embryos in Clinic 44]. Also, [The Preservation of Supernumerary Embryos and Their Thaw State in Clinic 44] supported "the supernumerary embryo preservation quantity" etc. In addition, [The Present State about Thaw and Use of Frozen Embryos in Clinic 44] or [The Book about Frozen Embryo Discard in Clinic 44] supported "the use and discard quantity of thawed embryos" etc. Moreover, "The embryo donation quantity" could be totalized in [The Present State about Donation and Charge of Frozen Embryos in Clinic 44]. Finally, [The Summarization Book about Management and Use of Frozen Embryos in Clinic 44] could be used for rational and consistent management or inspection. Conclusion: The present results suggest that the documents not only be standard data to record [The Book about Supernumerary Embryo Preservation in Clinic] and [The Book about Supernumerary Embryo Donation in Clinic] but can also be preserved as treatment references.

• The Science & Technology
• /
• v.35 no.8 s.399
• /
• pp.30-31
• /
• 2002