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Variable number of tandem repeat-polymerase chain reaction(VNTR-PCR) for engra
No full text의과학사업단/석사[한글]
동종조혈모세포이식 후 환자의 조혈기능이 일부 잔류하는 상태를 혼합 키메리즘(mixed chimerism)이라 하며, 혼합 키메리즘의 지속 또는 재현이 이식거부반응 또는 재발과 연관되어있다고 알려져 있다. 따라서 키메리즘의 확인은 동종조혈모세포이식 후 이식편의 생착 확인 이외에도 거부반응 및 재발의 가능성 등을 평가할 수 있는 유용한 지표로 생각된다. 동종조혈모세포이식 후 키메리즘 상태를 확인하는 생착검사 중 사람 유전자의 인트론 부위 내에 무작위로 산재해있는 단순반복배열인 microsatellite의 다형성을 이용하여 혼합 키메리즘을 검색하는 variable number of tandem repeats-polymerase chain reaction (VNTR-PCR) 방법은 민감도(0.01-0.1%)가 높으며, DNA 필요량이 적고, DNA 분리과정이 간단하여 기존의 다른 생착검사법에 비해 많은 장점을 가진 방법이다.
본 연구에서는 혈액질환으로 동종조혈모세포이식술을 시행 받은 환자 10례를 대상으로 VNTR-PCR 방법을 이용하여 이식 후 1-4주 간격으로 환자의 키메리즘 상태를 확인하였다. 10례 중 8례에서 이식 후 28일째 완전 키메리즘 상태가 확인되었고 2례에서는 이식 후 14일째 완전 키메리즘이 확인되었다. 1례에서는 이식 후 554일째, 혈액학적 완전관해상태에서 혼합 키메리즘(환자 DNA 53.1%)의 재현이 관찰되어 밀착추적관찰 중이다.
본 연구를 통해 VNTR-PCR 방법이 키메리즘 상태를 확인하고 생착 여부 및 재발 여부를 예측할 수 있는 유용한 방법임을 알 수 있었다.
[영문]
Mixed chimerism are defined as a state of mixture of both donor and recipient cells after allogeneic transplantation. Chimerism analysis after allogeneic hematopoietic stem cell transplantation allows detection of early marrow engraftment, disease relapse, and graft rejection. Among various analytical methods, VNTR-PCR has many theological advantages including increased sensitivity,
the use of smaller quantities of DNA, easier preparation of the DNA, faster turnaround time, the elimination of restriction enzymes and radioisotopes, and overall cost reduction.
In this study, ten allogeneic hematopoietic stem cell transplantations in 10 adult patients suffering from different types of leukemia(n=7) or non-malignant hematologic disorders(n=3) were investigated. Patient- and donor-derived hematopoiesis were assessed at 1- to 4-week intervals in peripheral blood samples by VNTR-PCR. In 9 of 10 patients, the complete chimerism was documented day+28, and 1 patients showed the complete chimerism at day+14. In one CML patient who showed
normal hematologic parameters, the reappearance of mixed chimerism(recipient DNA:53.1%) was documented at day+554.
VNTR-PCR method is a useful analytical method in the detection of chimerism after allogeneic hematopoietic stem cell transplantation.ope
Exercise Perception duringHematopoietic Transplantation forHematological Cancer Patients
Full text linkThe purpose of this study is to understand exercise perception during hematopoietic transplantation for hematological cancer patients. In-depth interview along with observation and field-note were used to collect data from nine
hematological cancer patients undergoing recovery of hematopoietic transplantation. Phenomenological research method were used to gain a deep understanding of their experience. Eleven themes and five categorizes emerged from the data: ‘Pain of fighting with cancer’, ‘Desolate space’, ‘Exercise; another hope’, ‘Lack of exercise information’, and ‘Difficulty in practice.’ The results highlight the significant impact that cancer treatment has on hematological cancer patients. Hematological cancer patients undergoing high-dose treatment in desolate aseptic room, shared their perception of exercise barrier during treatment period. Although the patients perceived exercise to be beneficial and they wanted exercise to be part of the treatment programs, they were obscured and emphasized the difficulty of exercise in practice.ope
CD44-연관 신호전달체계 활성화에 의한 THP-1 세포 분화
No full textDept. of Medicine/박사[한글]
항 CD44 단클론 항체(A3D8)를 이용한 CD44와의 결합은 사람 백혈병 세포주인 THP-1의 단세포성 분화를 유도한다. 그러나 이러한 세포분화의 정확한 분자적 기전은 정확히 알려져 있지 않다. 본 연구에서 A3D8에 의한 THP-1의 분화에 있어 세포외 신호전달 활성화효소인 p38 mitogen-activated protein kinase(MAPK)와 phosphatidylinositol 3-kinase(PI3-K)/Akt 경로의 중요성에 대해 연구하였다. A3D8 처리 72시간 후에 THP-1 세포는 성숙 단세포의 전형적인 세포 특징을 보였으며, 단세포-특이 세포표면항원인 CD14(1.8±0.1%에서 38.2±3.2%)와 골수계 특이 항원인 CD11b(6.6±0.6%에서 66.6±1.6%) 표현이 증가하였다. 이러한 분화관련 항원의 증가는 A3D8의 처리량 및 시간에 의존적이었다. A3D8 단클론 항체에 의한 CD44 결합은 인산화 Raf-1, 인산화 MEK1/2 및 인산화 ERK1/2와 같은 세포외 신호조절 활성화효소 경로의 주요 활성화효소들의 빠르고 지속적인 활성화를 유도하였다. 또한, A3D8 단클론 항체에 노출된 직후 THP-1 세포에서 Ser473 Akt 인산화가 관찰되었으며, 이후 인산화가 지속되었다. 반면에 p38 MAPK 인산화는 CD44 결합에 의해 감소되었다. MEK1 억제제인 PD98059 및 U0126을 THP-1세포에 전처지하였을 때, A3D8에 의한 MEK1/2 및 ERK1/2 활성화는 물론 THP-1의 분화가 억제되었다. PI3-K 억제제인 LY294002 전처치 시에도 A3D8 단클론 항체에 의한 세포분화가 거의 완전히 억제되며, A3D8에 의한 MEK/ERK 활성화가 억제 되었고 Raf-1 활성화는 억제되지 않았다. 이상의 결과를 종합하여 볼 때, CD44 결합에 의한 THP-1 세포의 분화유도과정에서 PI3-K/Akt 경로와 Raf/MEK/ERK 경로가 중요한 역할을 하며, 이 두 신호전달체계가 서로 연결되어 있음을 확인할 수 있었다.
[영문]Ligation of CD44 with anti-CD44 monoclonal antibody(mAb), A3D8, induces mo- nocytic differentiation of human leukemia cell line THP-1. However, the underlying molecular mechanisms remain largely unknown. Herein, we examined the importance of extracellular signal-regulated kinases, p38 mitogen-activated protein kinase(MAPK), and phosphatidylinositol 3-kinase(PI3-K)/Akt pathways in the A3D8-induced terminally differentiated THP-1 cells. THP-1 cells showed cytologic changes typical of mature monocytes and an increased expression of monocyte-specific antigen CD14(from 1.8±0.1% to 38.2±3.2%) and of myeloid-specific antigen CD11b(from 6.6±0.6% to 66.6±1.6%) 72hours after A3D8 treatment. The increase in the expression of these diffe- rentiation antigens was dose- and time-dependent. CD44 ligation with A3D8 mAb led to rapid and sustained activation of the essential kinases in the extracellular signal- regulated kinase pathway such as phospho-Raf-1, phospho-MEK1/2, and phospho-ERK1/2. In addition, Ser473 Akt phosphorylation was also observed shortly after the cells were treated with A3D8 mAb and was sustained thereafter. In contrast, the phosphorylation of p38 MAPK was dramatically decreased by CD44 ligation. Pre-treatment of cells with MEK1 inhibitors, PD98059 and U0126, potently inhibited THP-1 differentiation. Pre- treatment of cells with PI3-K inhibitor LY294002 also resulted in nearcomplete inhibition of A3D8 mAb-induced differentiation and also blocked the A3D8-induced MEK/ERK activation, but not the activation of Raf-1.Taken together, these findings demonstrated that the cross-talk between the activa- tion of A3D8-inducible PI3-K/Akt pathway and the Raf/MEK/ERK pathway in THP-1 cell exists, and plays a critical role during CD44 ligation-induced THP-1 differentiation.ope
High dose chemotherapy and autologous stem cell transplantation in non-Hodgkin's lymphoma: An eight-year experience
Full text linkAutologous stem cell transplantation (ASCT) is commonly used in relapsed or refractory non-Hodgkin's lymphoma (NHL). Several trials report the role of ASCT for high risk patients. We evaluated the results and the prognostic factors influencing the therapeutic effects on the patients who were treated with high dose chemotherapy (HDC) and autologous peripheral stem cell transplantation. We analyzed the data of 40 cases with NHL who underwent ASCT after HDC. Twenty-four patients had high-risk disease, 12 cases sensitive relapse, and two cases resistant relapse or primary refractory each. The median age of patients was 34 years (range, 14-58 years). The median follow-up duration from transplantation was 16 months (range, 0.6-94 months). Estimated overall survival and progression-free survival at 5 years were 40% and 30%, respectively. Poor prognostic factors for survival included older age (≥ 45 years), poor performance status in all patient analysis, and a longer interval between first complete remission and transplantation in high risk patients. In high risk NHL patients, transplantation should be done early after first complete remission to overcome chemo-resistance.ope
Akt Expression in Acute Leukemia Cells and Its Clinical Significance
Full text linkBACKGROUND :
Disturbances in apoptosis through phosphoinositide 3-kinase(PI3K)/Akt pathway is thought to be crucial in cancer cell immortality. Enhanced expression and activation of Akt was investigated in several malignancies but not in acute leukemia. We investigated the expression of Akt and phospho-Akt in acute leukemia cells and clinical characteristics of expression and non-expression group.
METHODS :
Bone marrow cells from patients who were newly diagnosed as acute leukemia and healthy volunteer were obtained and analyzed by Western blot analysis using monoclonal antibody against Akt, phospho-Akt (Ser473), and phospho-Akt (Thr308). Clinical data were obtained retrospectively.
RESULTS :
The expression of Akt was demonstrated in 27 of 43 cases (63%) and phospho- Akt(Ser473) was noted in 24 of 27 (54%) Akt-positive cases, respectively. Phospho-Akt (Ser473)-expression group showed significantly higher initial WBC counts compared to negative group (P=0.003). By chromosomal analysis, patients with Akt expression did not show any good prognostic karyotype (P=0.001).
CONCLUSION :
This result suggests that Akt overexpression and activation is detected in acute leukemia cells and might have a role in molecular pathogenesis of acute leukemia.ope
Therapeutic Comparison of Chemotherapy and Surgery for Early Stage Diffuse Large B-cell Gastric Lymphoma
Full text linkPURPOSE:
The use of surgery versus stomach-preserving treatment for primary gastric lymphoma has caused controversy among doctors. This retrospective, single center study aims to evaluate the efficacy and benefit of stomach-preserving treatment against surgery for early stage diffuse large B-cell lymphoma of stomach.
MATERIALS AND METHODS:
From August 1991 to January 2006, 43 cases of early-stage diffuse large B-cell gastric lymphoma were reviewed.
RESULTS:
Eleven cases were treated with chemotherapy or chemotherapy plus radiation (CT +/- RT), 17 were treated with surgery alone (OP), and 15 were treated with surgery plus adjuvant chemotherapy (OP + CT). The complete remission and response rates were 63.6% and 90.9% in those treated with CT +/- RT (7 complete responders, 3 partial responders, 1 non-responder), 100% and 100% in those treated with OP, and 100% and 100% in those treated with OP + CT, respectively. Five-year overall survival rates were 85.7%, 87.5%, and 100% in those treated by CT +/- RT, OP, and OP + CT, respectively (p=0.76). The five-year disease free survival rates were 100%, 87.5% and 100% in those treated by CT +/- RT, OP, and OP + CT, respectively (p=0.99). There was no significant difference in overall survival and disease free survival between modalities. Even though there are no definite differences in the number of complications between those treated by CT +/- RT or OP, these facts reflect little concern on complications after surgery.
CONCLUSION:
In preventing morbidity arising from early or late complications from surgery and promoting quality of life, chemotherapy should be a primary consideration for early stage diffuse large B-cell lymphoma of the stomach.ope
Study on Standard Setting Methods Applied to Medical School Class
No full text역량중심교육은 학생교육의 질적 강화 및 구체적인 교육효과를 요구하고 있다. 이를 위해서는 적절한 성취수준 설정 및 학생의 도달 여부를 확인하는 준거참조평가(절대평가)가 보다 적절할 것이다. 준거참조평가를 위해서는 준거설정방법을 통해 각 성취수준을 구분하는 분할점수를 산출해야 한다. 기존 준거설정방법들은 대부분 고부담시험에 적용되었으나, 대학의 수업수준에서 이뤄진 연구는 거의 없었다. 본 연구는 준거참조평가를 시행하는 의과대학의 실제 수업에서 활용하는 준거설정방법을 소개하였다. 이를 위해 준거설정방법 중 Modified Angoff 방법과 Modified Ebel 방법을 이용하여 성취수준별 분할점수를 산출했다. 산출결과 Modified Ebel 방법이 Modified Angoff 방법보다 엄격하게 평정되어 분할점수가 높았다. 또한 Modified Ebel 방법은 예상정답률과 실제정답률을 사용했을 때 분할점수에 차이가 있었으며, 실제정답률을 반영하는 것이 보다 현실적이었다. 본 연구는 고부담시험에서 주로 이뤄지는 준거설정을 실제 의과대학에서 사용하는 방법으로 의과대학 성적에 적용해 보았다는데 의의가 있다. 창의성 기반의 역량중심교육을 보다 활성화하려면, 경쟁에 관심을 두는 규준참조평가보다는 협력학습을 가능하게 하는 준거참 조평가가 더욱 강조될 것이고, 이때 다양한 준거설정방법이 수업수준에 적용될 것으로 예측된다.restrictio
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Biological Characteristics of AC133 Antigen-Positive Acute Leukemia
Full text linkBackground : AC133 antigen is a cell surface antigen which is selectively expressed on hematopoietc stem and progenitor cells. It has been reported that AC133 antigen is expressed on the subsets of CD34+ acute leukemia, and occasionally on CD34-acute leukemia. We investigated the clinical and biological characteristics of AC133 antigen-positive acute leukemia.
Method: Thirty-six adult acute leukemia patients were analyzed using a cut-off criterion of 20% or more gated leukemic blasts expressing the AC133 antigen for AC133+ leukemia. The biological characteristics focused on apoptosis were examined using multicolor flow cytometry and Western blot analysis.
Results: AC133 antigen was expressed in 12 cases (33.3%). Eleven of 21 (52.4%) acute myelogenous leukemia (AML) patients and 1 of 15 (6.7%) acute lymphoblastic leukemia patients were positive for AC133 antigen, and the difference was significant. None of the clinical prognostic markers were singificantly different between AC133+ and AC133- AML. Median disease free and overall survival time were not significantly different between AC133+ and AC133-
AML. The expression rate of CD34 was significantly higher in AC133+ AML patients compared to those of AC133- AML (P=0.045). Among the apoptosis-related proteins, the Fas expression on the leukemic blasts was higher in the AC133+ AML(P=0.048), but Fas ligand, Bcl-2, caspase-3 expression rates were not significantly different between AC133+ and AC133 -AML. The apoptosis rate was signigicantly lower in the Ara-C treated AC133 + AML (P=0.049), but the apoptosis rates to other apoptosis-inducing agents (dox-orubicin, TNF-α) were not different between AC133+ and AC133-AML cells. We thought that there were some associations between a trend toward higher caspase-3 expression rates and lower Ara-C induced apoptosis rates in the AC133+ AML.
Conclusion : There was no significant correlation between AC133 antigen expression and various clinical characteristics of acute leukemia, but the AC133 antigen might provide different biological characteristics including apoptosis from other immature cell surface markers. However, to verify the prognostic usefulness of AC133 antigen and the basis of the biological characteristics of AC133 antigen-positive acute leukemia, further study is needed.ope
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