• Journal of mucopolysaccharidosis and rare diseases
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• 제4권1호
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• pp.14-20
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• 2018

Mucopolysaccharidoses (MPSs) are a group of rare inherited metabolic disorders caused by specific lysosomal enzyme deficiencies leading to the sequential degradation of glycosaminoglycans, causing substrate accumulation in various cells and tissues and progressive multiple organ dysfunction. The rare disease medical care team at Mackay Memorial Hospital in Taiwan has been dedicated to the study of MPSs for more than 20 years. Since 1999, more than 50 academic papers focusing on MPSs have been published in international medical journals. Topics of research include the following items regarding MPSs: incidence, natural history, clinical manifestations, gene mutation characteristics, cardiac function, bone mineral density, sleep studies, pulmonary function tests, hearing assessments, percutaneous endoscopic gastrostomy, anesthetic experience, imaging analysis, special biochemical tests, laboratory diagnostics, global expert consensus conferences, prenatal diagnosis, new drug clinical trials, newborn screening, and treatment outcomes. Of these published academic research papers, more than half were cross-domain, cross-industry, and international studies with results in cooperation with experts from European, American and other Asian countries. A cross-specialty collaboration platform was established based on high-risk population screening criteria with the acronym "BECARE" (Bone and joints, Eyes, Cardiac and central nervous system, Abdomen and appearance, Respiratory system, and Ear, nose, and throat involvement). Through this platform, orthopedic surgeons, rheumatologists, ophthalmologists, cardiologists, rehabilitation physicians, gastroenterologists, otorhinolaryngologists, and medical geneticists have been educated with regards to awareness of suspected cases of MPSs patients to allow for a further confirmative diagnosis of MPSs. Because of the progressive nature of the disease, an early diagnosis and early multidisciplinary therapeutic interventions including surgery, rehabilitation programs, symptom-based treatments, hematopoietic stem cell transplantation, and enzyme replacement therapy, are very important.

• 식물조직배양학회지
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• 제27권6호
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• pp.423-428
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• 2000

In 1997 when cloned sheep Dolly and soon after Polly were born, it had become head-line news because in the former the nucleus that gave rise to the lamb came from cells of six-year-old adult sheep and in the latter case a foreign gene was inserted into the donor nucleus to make the cloned sheep produce human protein, factor IX, in e milk. In the last few years, once the realm of science fiction, cloned mammals especially in livestock have become almost commonplace. What the press accounts often fail to convey, however, is that behind every success lie hundreds of failures. Many of the nuclear-transferred egg cells fail to undergo normal cell divisions. Even when an embryo does successfully implant in the womb, pregnancy often ends in miscarriage. A significant fraction of the animals that are born die shortly after birth and some of those that survived have serious developmental abnormalities. Efficiency remains at less than one % out of some hundred attempts to clone an animal. These facts show that something is fundamentally wrong and enormous hurdles must be overcome before cloning becomes practical. Cloning researchers now tent to put aside their effort to create live animals in order to probe the fundamental questions on cell biology including stem cells, the questions of whether the hereditary material in the nucleus of each cell remains intact throughout development, and how transferred nucleus is reprogrammed exactly like the zygotic nucleus. Stem cells are defined as those cells which can divide to produce a daughter cell like themselves (self-renewal) as well as a daughter cell that will give rise to specific differentiated cells (cell-differentiation). Multicellular organisms are formed from a single totipotent stem cell commonly called fertilized egg or zygote. As this cell and its progeny undergo cell divisions the potency of the stem cells in each tissue and organ become gradually restricted in the order of totipotent, pluripotent, and multipotent. The differentiation potential of multipotent stem cells in each tissue has been thought to be limited to cell lineages present in the organ from which they were derived. Recent studies, however, revealed that multipotent stem cells derived from adult tissues have much wider differentiation potential than was previously thought. These cells can differentiate into developmentally unrelated cell types, such as nerve stem cell into blood cells or muscle stem cell into brain cells. Neural stem cells isolated from the adult forebrain were recently shown to be capable of repopulating the hematopoietic system and produce blood cells in irradiated condition. In plants although the term$\boxDr$ stem cell$\boxUl$is not used, some cells in the second layer of tunica at the apical meristem of shoot, some nucellar cells surrounding the embryo sac, and initial cells of adventive buds are considered to be equivalent to the totipotent stem cells of mammals. The telomere ends of linear eukaryotic chromosomes cannot be replicated because the RNA primer at the end of a completed lagging strand cannot be replaced with DNA, causing 5' end gap. A chromosome would be shortened by the length of RNA primer with every cycle of DNA replication and cell division. Essential genes located near the ends of chromosomes would inevitably be deleted by end-shortening, thereby killing the descendants of the original cells. Telomeric DNA has an unusual sequence consisting of up to 1,000 or more tandem repeat of a simple sequence. For example, chromosome of mammal including human has the repeating telomeric sequence of TTAGGG and that of higher plant is TTTAGGG. This non-genic tandem repeat prevents the death of cell despite the continued shortening of chromosome length. In contrast with the somatic cells germ line cells have the mechanism to fill-up the 5' end gap of telomere, thus maintaining the original length of chromosome. Cem line cells exhibit active enzyme telomerase which functions to maintain the stable length of telomere. Some of the cloned animals are reported prematurely getting old. It has to be ascertained whether the multipotent stem cells in the tissues of adult mammals have the original telomeres or shortened telomeres.

• 대한임상검사과학회지
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• 제38권1호
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• pp.9-15
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• 2006

Peripheral bood stem cell collection (PBSCC), including peripheral blood stem cell transplantation (PBSCT), has been utilized worldwide as a very beneficial treatment method instead of allogenic Bone Marrow Transplantation (BMT) because it has many advantages such as rapid bone marrow engraftment and hematopoietic recovery, easy and safe accessibility and lower risk of rejection compared with allogenic BMT. In order to identify most the observable parameter in PBSCC, we analyzed various hematological parameters before and after PBSCC, and evaluated the correlation between the time of bone marrow engraftment and the number of CD34+ cells. Thirteen patients, who underwent 54 PBSCCs from January, 2003 to August, 2004 at Chungnam National University Hospital due to various systemic neoplasms, were analyzed in aspects of various hematological parameters including CD34+ cells using by Flow Cytometry (FCM). PBSCC harvests are described below: Mononuclear cells (MNC) $2.3{\pm}1.4{\times}10^8/kg$ and CD34+ cells $0.63{\pm}0.35{\times}10^6/kg$ on average, respectively. There was a statistical significance in Hb and Hct before and after PBSCC, but not in WBC and platelet counts. The period to reach the hematological bone marrow engraftment was 13.4(10~21) days and 19.5(11~38) days according to the criteria of absolute neutrophile counts (ANC) ${\geq}500/uL$ and platelet counts ${\geq}50,000/{\mu}L$ in peripheral blood, respectively. There was a significant correlation between the numbers of CD34+ cell and ANC (p<0.05), and a borderline significance between MNC and ANC (p=0.051). We found that a group of patients, who were infused with CD34+ cells more than $3.5{\times}10^6/kg$, reached more rapidly the period of bone marrow engraftment in platelet counts (p=0.040). This present study suggested that Hb and Hct were the most useful parameters and should be closely monitored before and after PBSCC, that a PBSCT with the dosage of more than $3.5{\times}10^6/kg$ of CD34+ cells was needed to perform successful bone marrow engraftment, and additionally that platelet counts could be more useful in indicating bone marrow engraftment than ANC.

• Clinical and Experimental Pediatrics
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• 제50권6호
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• pp.524-530
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• 2007

The recent advances in the basic hematology and immunology have significantly enhanced the understanding of histiocytic disorders. The Histiocyte Society which was established in 1985 enabled the randomized trials for these diseases, and important knowledge regarding pathogenesis, clinical presentation, diagnosis, therapy and late consequences has been obtained. The treatment of Langerhans cell histiocytosis (LCH) has varied greatly over last decades, and is still controversial. Therapy can be reduced for low risk patients, and it is possible to discriminate early the non-responding patients with risk disease who might require more intensified treatment. Current therapy of LCH recommended by the Histiocyte Society (LCH-III protocol) is activated in 2001. Hemophaocytic histiocytosis (HLH) is fatal if diagnosis is delayed and appropriate therapy is not instituted rapidly. The diagnostic criteria for HLH is revised by the Histiocyte Society for the current treatment protocol (HLH-2004) which consists of dexamethasone, etoposide, and cyclosporin in combination with intathecal methotrexate. Hematopoietic stem cell transplantation is usually necessary for the primary HLH and recurrent secondary HLH.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.422-428
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• 2003

Umbilical cord blood (UCB), a rich source of hematopoietic stem/progenitor cells, has been proposed as an alternative to bone marrow and peripheral blood for transplantation treatment. Ex vivo expansion of cord blood stem cells could make the use of cord blood transplant feasible even for adult patients. However, the optimal cytokine cocktail for expansion of stem cells is yet to be established. This study compares proliferation, apoptosis, and telomerase activities in human cord blood stem cells cultured ex vivo with FLT3 ligand (FL)/thrombopoietin (TPO) or FL/TPO/stem cell factor (SCF), with a view to determine optimal combination of cytokines. CD34+ cells were cultured in DMEM containing either FL (50 ng/ml) and TPO (10 ng/ml) (FT group) or FL (50 ng/ml), TPO (10 ng/ml) and SCF (50 ng/ml) (FTS group). The cell proliferation rate was ten times higher in the FTS group. Although cells cultured with the two different combinations of cytokines were maintained for a long term (up to 8 weeks), a large number of cells underwent differentiation during this period. Cells cultured in FTS displayed lower levels of apoptosis compared to those of the FT group during the Initial 7 days of culture. The CD34+ fraction in both groups was markedly decreased to $21-30\%$ , and only $5-6\%$ was detected at 14 days of culture. Telomerase activity detected in human CD34+ cord blood at low levels was upregulated during the early phase of culture and decreased to baseline levels in the later phase. The telomerase activity of cord blood cultured in FT was lower than that of the FTS group. Our results suggest that, on adding stem cell factors to the FT cytokines, cultured CD34+ cord blood cells display a greater degree of cell proliferation and decreased apoptosis. However, during CD34+ cord blood cell culture, a Barge number of cells undergo differentiation, indicating that more potent novel cytokines or new culture conditioning methods should be developed to maintain their ability to engraft and sustain long-term hematopoiesis.

• KSBB Journal
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• 제14권5호
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• pp.593-599
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• 1999

본 연구는 제대혈과 골수로부터 얻은 조혈모세포를 재조합 retrovirus로 감염시킬 때의 최적조건을 human growth hormone (hGH)과 $\beta$-galactosidase를 발현하는 두 가지의 다른 retroviral vector를 이용하여 찾았다. Retrovirus는 자라는 세포에만 감염하는 것으로 알려져 있어 이에 대한 최적조건을 구하기 위해 세포 배양을 통해 조혈모세포의 성장곡선을 얻었으며, 또한 감염된 세포를 환자에게 다시 넣는 유전자요법에서는 이 세포가 체내에서 가능하면 조혈모세포의 기능을 가지는 것이 요구되어 이 때 얻어진 세포의 분열능을 나타내는 집락형성 세포분율을 구하였다. 우선, 세포성장에 대해 조사한 결과 초기에 넣은 세포농도가 5$\times$$10^4$세포/mL일 때 세포성장속도가 가장 빠른 것으로 나타났다. 그러나, 배양시간이 지남에 따라 집락을 형성할 수 있는 능력은 급격하게 감소하여 유전자요법을 위한 최적조건을 구하기 위해서는 이를 고려한 최적화가 필요하였다. 이를 위한 예비실험으로 감염이 잘 된다고 알려진 NIH3T3 세포에 retrovirus 상층액으로 감염시킨 결과 성공적으로 유전자가 전달된 것을 배지에 분비되는 hGH을 측정하여 확인하였다. 이러한 결과로부터 hGH을 발현하는 재조합 retrovirus는 정상적으로 작동하는 것을 확인하였다. 그러나, 조혈모세포와 retrovirus를 분비하는 packaging cell을 동시 배양하는 방법을 채택하였다. 제대혈로부터 얻은 조혈모세포와 대장균 lacZ 유전자로부터 $\beta$-galactosidase를 분비하는 packaging cell을 이용한 경우 동시배양의 경우 조혈모세포를 3일 동안 세포배양을 한 후 이 증식된 세포를 48시간 동안 동시배양하면서 감염시켰을 때 최대의 감염율을 나타내었다. 한편, 골수로부터 얻은 조혈모세포와 hGH을 분비하는 packaging cell과 동시배양시켰을 때 세포농도가 다름에도 불구하고 제대혈에서와 마찬가지로 조혈모세포를 3일 동안 세포배양한 후 48시간 동안 동시배양하는 경우에 hGH이 최대로 분비되었다. 이러한 결과로부터 세포의 source나 세포농도와 관계없이 유전자전달을 통한 단백질의 발현에 있어서 최적조건이 존재하였다. 그러나, 이러한 경우에 유전자전달이 완료되는 시점이 배양을 시작한지 5일이 되므로 집락을 형성할 수 있는 세포의 분율이 약 1/3로 감소하였다. 따라서, 이러한 결과를 유전자요법에 적용하는 경우에는 그 목적에 따라 적절한 실험조건을 선정하는 것이 필요하리라 사료된다.

• Journal of Chest Surgery
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• 제50권5호
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• pp.382-385
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• 2017

A 47-year-old man with myasthenia gravis (MG) was admitted for a lung transplant. He had bronchiolitis obliterans after allogeneic hematopoietic stem cell transplantation due to acute myeloid leukemia. MG developed after stem cell transplantation. Bilateral sequential lung transplantations and a total thymectomy were performed. The patient underwent right diaphragmatic plication simultaneously due to preoperatively diagnosed right diaphragmatic paralysis. A tracheostomy was performed and bilevel positive airway pressure (BiPAP) was applied on postoperative days 8 and 9, respectively. The patient was transferred to the general ward on postoperative day 12, successfully weaned off BiPAP on postoperative day 18, and finally discharged on postoperative day 62.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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• pp.55-58
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• 2004

Cell separation from peripheral blood was investigated using surface-modified polyurethane (PU) membranes with different functional groups. Both red blood cells and platelets could pass through unmodified PU and PU-SO$_3$H membranes, while the red blood cells preferentially passed through PU-N(C$_2$H$_{5}$ )$_2$ and PU-NHC$_2$H$_4$OH membranes. The permeation ratio of T and B cells was less than 25% for the surface-modified and unmodified PU membranes. CD34$^{+}$ cells have been recognized as various kinds of stem cells including hematopoietic and mesenchymal stem cells. The adhesiveness of CD34$^{+}$ cells on the PU membranes was found to be higher than that of red blood cells, platelets, T cells or B cells. Overall, the adhesiveness of blood cells on the PU membranes increased in the following order: red blood cells $\leq$ platelets ＜ T cells $\leq$ B cells ＜ CD34$^{+}$ cells. Treatment of PU-COOH membranes with a human albumin solution to detach adhered blood cells, allowed recovery of mainly CD34$^{+}$ cells in the permeate, while both red blood cells and platelets could be isolated in the permeate using unmodified PU membranes. The PU membranes showed different permeation and recovery ratios of specific cells depending on the functional groups attached to the membranes.mbranes.

• 한국발생생물학회지:발생과생식
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• 제12권1호
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• pp.67-76
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• 2008

Reactive oxygen species(ROS)에 의한 산화적 손상은 냉동보존 과정과 체외 배양과정 중 세포 생존률 감소의 주된 요인 중 하나이며, 특히 줄기세포의 경우 냉동보존 후 쉽게 분화하거나 사멸하는 경향이 있음이 잘 알려져 있다. 따라서 본 연구는 체외 배양된 인간 조혈모 줄기세포의 냉동보존 시 선별된 항산화제를 처리하여 항산화제가 줄기세포의 생존 및 자동분화에 미치는 영향을 조사하고자 하였다. 해동 후 세포의 생존률은 $\alpha$-tocopherol과 ascorbic acid 처리군이 대조군($62.7{\pm}8.0%$)에 비해 높은 생존률을 보였고, 그 중 150 uM $\alpha$-tocopherol처리군($70.5{\pm}7.0%$)이 가장 높은 생존률을 보였다. 세포막 손상은 대조군 및 실험군 모두에서 나타나지 않았다. 자동분화율에 있어서는 모든 실험군에서 대조군($10.1{\pm}1.6%$)과 유의한 차이를 보이지 않았으나, 150 uM $\alpha$-tocopherol ($7.3{\pm}2.6%$) 처리군에서 가장 낮은 자동분화율을 나타내었다. 본 실험의 결과, 항산화제는 인간 조혈모 줄기세포 냉동보존 시 생존율을 향상시키며, 특히 $\alpha$-tocopherol은 인간 조혈모 줄기세포의 냉동보존 과정 동안 효과적인 항산화제로 작용할 것이라 생각된다.

• Clinical and Experimental Pediatrics
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• 제59권4호
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• pp.190-195
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• 2016

Purpose: Severe aplastic anemia (SAA), a fatal disease, requires multiple transfusion, immunosuppressive therapy, and finally, hematopoietic stem cell transplantation (HSCT) as the definitive treatment. We hypothesized that iron overloading associated with multiple transfusions and HSCT-related complications may adversely affect cardiac function. Left ventricular (LV) function was assessed in children after HSCT for SAA. Methods: Forty-six consecutive patients with a median age of 9.8 years (range, 1.5-18 years), who received HSCT for SAA and who underwent comprehensive echocardiography before and after HSCT, were included in this study. The data of LV functional parameters obtained using conventional echocardiography, tissue Doppler imaging (TDI), and speckle-tracking echocardiography (STE) were collected from pre- and post-HSCT echocardiography. These data were compared to those of 40 age-matched normal controls. Results: In patients, the LV ejection fraction, shortening fraction, end-diastolic dimension, mitral early diastolic E velocity, TDI mitral septal E' velocity, and STE LV longitudinal systolic strain rate (SSR) decreased significantly after HSCT. Compared to normal controls, patients had significantly lower post-HSCT early diastolic E velocity and E/A ratio. On STE, patients had significantly decreased LV deformational parameters including LV longitudinal systolic strain (SS), SSR, and diastolic SR (DSR), and circumferential SS and DSR. Serum ferritin levels showed weak but significant correlations (P<0.05) with LV longitudinal SS and SSR and circumferential SS and DSR. Conclusion: Subclinical LV dysfunction is evident in patients after HSCT for SAA, and was associated with increased iron load. Serial monitoring of cardiac function is mandatory in this population.