• Molecules and Cells
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• 제41권2호
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• pp.134-139
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• 2018

Here, we report isolation of multiple long non-coding RNAs (lncRNAs) expressed tissue-specifically during murine embryogenesis. One of these, subsequently came to be known as Redrum, is expressed in erythropoietic cells in fetal liver and adult bone marrow. Redrum transcription is also detected during pregnancy in the spleen where extramedullary hematopoiesis takes place. In order to examine the function of Redrum in vivo, we generated a gene-targeted murine model and analyzed its embryonic and adult erythropoiesis. The homozygous mutant embryo showed no apparent deficiency or defect in erythropoiesis. Adult erythropoiesis in bone marrow and in the spleen during pregnancy likewise showed no detectable phenotype as red blood cells matured in normal fashion. The phenotype is in contrast to the reported function of Redrum in vitro, and our observation implies that Redrum plays in vivo an accessory or supplementary role whose loss is compatible with normal erythropoiesis.

• 대한핵의학회:학술대회논문집
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• 대한핵의학회 1972년도 제11차 학술대회
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• pp.67.3-67.3
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• 1972

• BMB Reports
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• 제38권3호
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• pp.328-333
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• 2005

A human homologue of Sar1, named Sara2, was shown to be preferentially expressed during erythropoiesis in a culture stimulated by EPO. Previous studies, in yeast, have shown that secretion-associated and Ras-related protein (Sar1p) plays an essential role in protein transport from the endoplasmic reticulum to the Golgi apparatus. Here, we report the molecular analysis of Sara2 in erythroid cell culture. A 1250 bp long cDNA, encoding a 198 amino-acid protein very similar to Sar1 proteins from other organisms, was obtained. Furthermore, we also report a functional study of Sara2 with Real-time quantitative PCR analysis, demonstrating that expression of Sara2 mRNA increases during the initial stages of erythroid differentiation with EPO and that a two-fold increase in expression occurs following the addition of hydroxyurea (HU). In K562 cells, Sara2 mRNA was observed to have a constant expression and the addition of HU also up-regulated the expression in these cells. Our results suggest that Sara2 is an important gene in processes involving proliferation and differentiation and could be valuable for understanding the vesicular transport system during erythropoiesis.

• Applied Microscopy
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• 제29권1호
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• pp.43-56
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• 1999

태생기 간 적혈구형성 중 혈관밖공간의 미성숙 적혈구모세포의 일부는 동굴모세혈관 속공간으로 이주하며, 별큰포식세포에 의해 영향을 받는다. 본 연구에서는 혈관속공간에 이주한 미성숙 적혈구모세포와 별큰포식세포의 관계를 규명하고자 간 적혈구형성의 활성도가 높게 유지되는 태령 제 11주부터 태령 제 20주에 이르는 태아 간과 쥐 태자 간의 연구재료를 대상으로 투과 및 주사전자현미경 관찰을 통해 다음과 같은 결론을 얻었다. 1) 별큰포식세포는 성인 간이나 다른 태령 시기에 비해 비대하였고 많은 세포질돌기들을 갖고 있었다. 이 세포는 부분적으로 세포분열에 의해 증식되고 있었으며 성인 간의 별큰포식세포와 다르게 자가종식을 할 수 있었다. 3) 호산성적혈구모세포에서 탈출된 핵은 별큰포식세포의 속공간쪽과 간세포쪽 세포막에서 포식되었다. 포식된 핵은 주변 부위에 층판이 형성되거나 및 개의 작은 조각으로 파괴되는 등 다양한 소화과정을 보였다. 3) 동굴모세혈관 속공간에서 별큰포식세포는 미성숙적혈구모세포들과 직접으로 접촉하거나, 미성숙 적혈구 모세포들 사이에 별큰포식세포의 긴 세포질돌기가 뻗쳐 있어 골수 적혈구형성에서 관찰되는 적혈구모세포섬과 비슷하였다. 이상의 결과를 종합하면 태아 간 적혈구형성이 왕성한 시기의 별큰포식세포는 적혈구를 포식하는 것 외에도, 세포가 비대해져서 동굴모세혈관을 통한 혈액흐름을 감소시키고, 적혈구모세포섬을 구성하여 태아 간 적혈구형성에서 미성숙 적혈구모세포의 성숙과 관련된 기계적 및 생리학적 기능을 수행한다고 생각된다.

• 치과방사선
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• 제17권1호
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• pp.27-49
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• 1987

Using ³H-proline as a radioactive tracer, the relationship between the ultrastructural differentiation and the site of protein synthesis has been investigated in developing red blood corpuscles. The general ultra-structure of erythropoietic cells in differentiation after 60 minutes of in vitro labeling has confirmed the results from previous investigations by Bessis, M., Thiery, J. and others. In dividing nuclei more than two-thirds of the labeling were present at the interface between heterochromatin and euchromatin. In less differentiated cells most of the grains in interphase cells was localized over the nucleus. As the cells continued to develope beyond a stage where cytoplasmic density was clearly increased over other cell lines in bone marrow, the majority of grains localized over the cytoplasmic area was decreased in more mature cells, as judged by the density of cytoplasm, and the structural changes in mitochondria, Golgi complex and polysomal configurations. These results show; 1) that the cytoplasm of erythroblast series does not change under in vitro conditions employed in the study; 2) that protein synthesis in the nucleus occurs largely at the interface between euchromatin and heterochromatin in active nuclei; and 3) that cytoplasmic synthesis of proteins continues to take place well into the normoblast stage solong as the physically visible polysomes are present in maturing red blood corpuscles.

• Biomolecules & Therapeutics
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• 제11권2호
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• pp.126-132
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• 2003

Efficacy and in vivo bioassay of recombinant human erythropoietin (rh-EPO, DWP413) was investigated. Efficacy studies on erythropoiesis were conducted in normal, cisplatin-induced anemic rats and acute hemorrhage - induced anemic rats. Animals were treated intravenously with DWP413 for 5 days, the changes in the number of red blood cells (RBC), hematocrit value (Hct), hemoglobin concentration (Hb) and reticulocyte were examined. In normal rats, at the doses of 50, 250, and 1250 IU/kg/day, in cisplatin-induced anemic rats, at the doses of 50, 100 and 200 IU/kg/day, RBC, Hb, Hct and reticulocyte were increased dose-depen-dently. And in acute hemorrhage-induced anemic rats, DWP413 (150, 450 and 1350 IU/kg/day) significantly increased RBC, Hb, Hct and reticulocytes. In histopathological findings of kidney, cisplatin alone treated rats expressed severe glomerulus and tubular damage. But in the DWP413 treated rats after cisplatin treatment, these were not remarkable compared to cisplatin alone treated rats. In vivo bioassay, DWP413 had 102.43% of bioactivity compared to erythropoietin BRP(Biological Reference Product, European Directorate for the Quality of Medicines). These results suggest that DWP413 might be useful for the therapy of anemia induce by renal failure and acute blood loss.

• 약학회지
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• 제47권6호
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• pp.422-431
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• 2003

The use of recombinant human erythropoietin (rhEPO), a stimulator of erythropoiesis, banned in sports because of the medical risk associated with thrombosis. Due to analytical difficulties to differentiate between natural human EPO (hEPO) and rhEPO, blood parameters of erythropoiesis such as contents of hemoglobin (cut-off value <17.5 g/d l for man, and < 16.0 g/dl for women), hematocrit and reticulocytes (cut-off value <2.0%) were measured to focus the misuse of rhEPO. We conducted anti-doping test for 122 blood samples of the World Cup athletes. The mean values of key parameters are as follows; 14.5$\pm$1.0 g/dl for hemoglobin, 41.7$\pm$2.8% for hematocrit, and 1.3$\pm$0.4% for reticulocyte. Blood sample was found to be stable up to 8 hours for the reticulocyte measurement. In addition, the soluble transferrin receptor and ferritin levels were measured by immunoassay methods using plasma samples (n=28) in which the mean value was 0.8$\pm$0.5 $\mu\textrm{g}$/$m\ell$ and 54.6$\pm$33.7 ng/$m\ell$, respectively. The results indicate that all samples tested were negative for the blood parameters of indirect anti-doping test for hEPO misuse. The statistical evaluation suggest that several other parameters such as red blood cell, mean corpuscular hemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin and white blood cell could be considered as factors influencing hEPO function in addition to five parameters mentioned.

• Applied Microscopy
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• 제15권2호
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• pp.19-30
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• 1985

Morphogenesis of rat spleen was studied by light and electron microscope from the fetal stage till the newborn or adult stages. The results indicate as follows: at the 14th day of gestation rat spleen, as an early form, consists of intercellular spaces and mesenchymal cells. And at this stage the spleen is in a premature state, then it appears its adult condition in structures after the 7th postnatal day. Erythropoiesis is shown to be an active process in rat spleen beginning about the 18th day of gestation, and once established the process continues at least till the 7th postnatal day. At the 20th day of gestation, there are splenic nodules, trabeculae, venous sinus, and granular leucocytes such as neutrophils and basophils in rat spleen. Lymphocytes appeared to be well differentiated at the 7th postnatal day and were present till the adult stage. While degenerating erythrocytes are phagocytosed by macrophages. In conclusion, rat spleen started to be appeared from the 14th day of gestation and erythropoiesis in rat spleen was carried out for about 10 days between prenatal and postnatal stage. Erythrophagocytosis was accomplished by macrophages and it is suggested that the proper functions of rat spleen set off from the 7 th postnatal day when its structures are similar to the adult's.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.88-88
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• 2002

Erythropoietin (EPO)는 조혈작용 (erythropoiesis)을 나타내는 호르몬으로서 사람의 빈혈치료제로 사용되며, 포유통물 중 사람, 생쥐 등의 유즙 내에 혈청 EPO 와 동일한 크기로 다량으로 존재한다고 보고된 바 있다. 생쥐의 WAP promoter를 이용하여 사람의 조혈촉진제인 EPO를 유즙으로 생산하는 형질전환돼지 (새롬이)의 유즙을 분석하기 위해 SDS-PAGE와 Western blotting 을 수행하였다. 먼저, 형질전환돼지의 유즙으로부터 원심분리에 의해 지방층을 제거한 후, 16.5% polyacrylamide gel 에서 PAGE를 수행하였다. (중략)

• 한국동물학회지
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• 제39권3호
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• pp.239-247
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• 1996

현탁 배양액에서 생쥐 배아주 세포를 배아체(embryoid body. EB)로 분화시키는 간단한 시험내 모델 체계가 초기 적혈구 분화 분석에 유용한 지의 여부를 조사하였다. 분화중인 배아체로부터 각 혈구계열 세포 유형이 만들어지는 지(분화능)의 여부는 혈도형성, benzidine 염색법 및 2단계 콜로니 분석법을 조사하였고, 발생과 분화시기에 바ㅈ추어 적혈구 표시 유전자들이 발현되는 지(발현능)의 여부는 각 분화시기별 배아체로 부터 추출한 RNA를 RT-PCR 방법으로 조사하였다. 분석 결과, 다른 기존의 복잡한 분화 방법에 의한 것과 마찬가지로 모든 혈구계열 세포 유형이 반복성 있게 유도되었다. 더군다나, 분화중인 배아주 세포에서의 글로빈 유전자 발현 전환은 생쥐 배아에서와 유사하게 진행되었으며, 글로빈 유전자의 발현은 적혈구-특이 전사인자인 GATA-1과 Tal-1보다 적어도 12시간 늦게 활성화되었다. 이와같이 간단한 분화 체계에서도 적혈구 분화과정이 효율적으로 반복성 있게 나타나는 것으로 보아, 간단한 현탁배양에서의 분화는 초기 적혈구 분화과정이 분자적 기작을 분석하는데 유용하게 이용될 수 있으리라 본다.