• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2017년도 춘계공동학술대회
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• pp.107-107
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• 2017

3D bioprinting is a technology to produce complex tissue constructs through printing living cells with hydrogel in a layer-by-layer process. To produce more stable 3D cell-laden structures, various materials have been developed such as alginate, fibrin and gelatin. However, most of these hydrogels are chemically bound using crosslinkers which can cause some problems in cytotoxicity and cell viability. On the other hand, thermosensitive hydrogels are physically cross-linked by non-covalent interaction without crosslinker, facilitating stable cytotoxicity and cell viability. The examples of currently reported thermosensitive hydrogels are poly(ethylene glycol)/poly(propylene glycol)/poly(ethylene glycol) (PEG-PPG-PEG) and poly(ethylene glycol)/poly(lactic acid-co-glycolic acid) (PEG/PLGA). Chitosan, which have been widely used in tissue engineering due to its biocompatibility and osteoconductivity, can be used as thermosensitive hydrogels. However, despite the many advantages, chitosan hydrogel has not yet been used as a bioink. The purpose of this study was to develop a bioink by chitosan hydrogel for 3D bioprinting and to evaluate the suitability and potential ability of the developed chitosan hydrogel as a bioink. To prepare the chitosan hydrogel solution, ${\beta}-glycerolphosphate$ solution was added to the chitosan solution at the final pH ranged from 6.9 to 7.1. Gelation time decreased exponentially with increasing temperature. Scanning electron microscopy (SEM) image showed that chitosan hydrogel had irregular porous structure. From the water soluble tetrazolium salt (WST) and live and dead assay data, it was proven that there was no significant cytotoxicity and that cells were well dispersed. The chitosan hydrogel was well printed under temperature-controlled condition, and cells were well laden inside gel. The cytotoxicity of laden cells was evaluated by live and dead assay. In conclusion, chitosan bioink can be a candidate for 3D bioprinting.

• Asian Pacific Journal of Cancer Prevention
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• 제16권16호
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• pp.7327-7330
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• 2015

Background: Essential thrombocythemia (ET) is a clonal hemopoietic stem cell myeloproliferative neoplasm characterized by persistent thrombocytosis along with megakaryocytic hyperplasia. In the last decade following the identification of an acquired JAK2 V617F mutation, there has been acceleration in our understanding of this disease. The rational of this study was to determine the mutational profile of JAK2 V617F in Pakistan patients with ET. Materials and Methods: In this retrospective cross sectional study, 21 patients with ET were enrolled from January 2011 to December 2014. Patients were diagnosed based on WHO criteria for essential thrombocythemia. Complete blood count was done on an automated hematology analyzer, while JAK2 V617F expression was evaluated by polymerase chain reaction. Results: The mean age was $56.7{\pm}19.0$ years (range 18-87) and the male to female ratio was 1:1.1. The frequency of JAK2 V617F positivity in our ET patients was found to be 61.9%. The mean hemoglobin was $11.7{\pm}2.4$ g/dl with a total leukocyte count of $13.3{\pm}8.1{\times}109/l$ and a platelet count of $1188{\pm}522{\times}109/l$. Positive correlations for JAK2 V617F mutation were established with high TLC count and raised LDH (P<0.05). No correlation of JAK2 V617F could be established with age and gender (P>0.05). Conclusions: JAK2 V617F mutation frequency in our ET patients was similar to those reported previously. Screening for the mutation in all suspected essential thrombocythemia cases could be beneficial in differentiating patients with reactive and clonal thrombocytosis.

• Journal of Animal Science and Technology
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• 제48권1호
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• pp.1-8
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• 2006

포유동물에서 KIT 유전자는 우성 백색의 모색발현에 관여하는 후보유전자로서 mast/stem cell growth factor receptor를 암호화하는 것으로 알려져 있다. 본 연구에서는 한반도에서 서식하고 있는 야생멧돼지의 모색발현에 있어서 KIT 유전자의 유전적 변이를 확인하기 위하여 PCR- RFLP와 염기서열 분석을 수행하여 유전적 변이를 관찰하였다. 멧돼지 KIT 유전자의 exon17- intron 17 경계부위에 대한 NlaⅢ-RFLP 결과 splicing mutation이 없고, exon 19 상에서의 SNP C2678T에 대한 AciⅠ-RFLP 결과 역시 백색 품종들의 유전자형과는 다르게 나타났다. 이상의 결과는 멧돼지 집단 내 교잡에 의해 백모색의 자손이 출현하지 않음을 의미한다. 또한 exon 19과 exon 20에서 새로운 SNP들이 확인되었으며 이들 중 exon 20에서의 SNP A2760G는 아미노산의 변화(iso-leucine→valine)를 초래할 수 있으나 모색 발현과의 연관은 확인할 수 없었다. 돼지 KIT 유전자의 exon 19, 20과 intron 19 상에서의 새로 발견된 SNP와 splicing mutation의 존재 여부 등은 품종특이적인 양상으로 확인되었고, 이 같은 결과는 돼지에서 백색 모색 발현을 설명할 수 있는 좋은 자료가 될 것으로 사료된다.

• IMMUNE NETWORK
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• 제5권3호
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• pp.179-185
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• 2005

Background: Psoriasis is a multifactorial autoimmune skin disease with a pathogenesis that has remained obscure. Recently, T cells bearing natural killer receptors (NKRs) were precisely and strongly targeted as new putative pathogenic immunocytes in psoriasis. Among NKRs, killer cell immunoglobulin-like receptor (KIR) is the major molecule recognizing HLA class I allotypes and might be closely related to psoriasis. Methods: To investigate the association of KIR genotype and patients with psoriasis in Korean, we defined the 14 KIR genotypes in 96 patients with psoriasis and 86 healthy controls using PCR-SSP methods. Results: The frequencies of KIR2DS4 and KIR3DL1 were significantly decreased in psoriasis compared with controls (RR=0.21, p<0.02). When patients were divided into two subgroups at the age of onset, type I (<30 years) and type II ($({\geq}30$ years) respectively, these phenomena were similarly observed independent of groups divided (type I: RR=0.26, p<0.005; type II: RR=0.14, p<0.0006). When the patients were divided into subgroups according to the age of onset and family history, the frequencies of KIR2DS4, KIR3DL1, and KIR2DS3 were significantly decreased in type I compared with type II psoriasis (3DL1, 2DS4: p<0.004; 2DS3: p<0.04) and were significantly decreased in psoriasis without family history compared to with family history (3DL1, 2DS4: p<0.007; 2DS3: p<0.05). The frequency of haplotype combination BB was significantly increased in psoriasis compared with controls (RR=2.74, p<0.009). Conclusion: These results suggest that KIR genotype is a factor for the occurrence and development of psoriasis and in future how combinations of HLA and KIR genes influence psoriasis needs to be defined.

• 생물정신의학
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• 제7권2호
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• pp.147-151
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• 2000

Objective : Major depression is known to have immunologic dysfunctions, the recent studies revealed that cytokines including IL-6 and IL-$1{\beta}$ were increased in patients with major depression. Since molecular genetic methods have been progressed, this study was to investigate the relationship between major depression and immunologic aspects by analyzing polymorphism of IL-10 gene. Method : 92 patients with major depression were included and data of 146 normal controls obtained from the Catholic Hemopoietic Stem Cell Information Bank of Korea were used in this study. DNA was extracted from whole blood, thereafter amplified by polymerase chain reaction, and digested by Mae III After that procedure, we obtained and assessed RFLP of two alleles, IL-10T and IL-10C. All data were analyzed by ${\chi}^2$ test. Results : 1) There were no significant difference in genotype frequencies of $IL-10^*T/T$, $IL-10^*T/C$, and $IL-10^*C/C$ between major depression patients group and control group. 2) There were no significant difference in allelic frequencies of $IL-10^*T$ and $IL-10^*C$ between major depression patients group and control group. Conclusion : We did not verified the differences in frequencies of $IL-10^*T/^*IL-10^*C$ gene between the major depression patients group and control group, respectively. But the results of this study do not declare that the IL-10 gene has no association with major depression. We do suggest that further systematic studies including various clinical variables should be conducted.