98 research outputs found
Hematopoietic Differentiation of Embryoid Bodies Derived from the Human Embryonic Stem Cell Line SNUhES3 in Co-culture with Human Bone Marrow Stromal Cells
Human embryonic stem (ES) cells can be induced to differentiate into hematopoietic precursor cells via two methods: the formation of embryoid bodies (EBs) and co-culture with mouse bone marrow (BM) stromal cells. In this study, the above two methods have been combined by co-culture of human ES-cell-derived EBs with human BM stromal cells. The efficacy of this method was compared with that using EB formation alone. The undifferentiated human ES cell line SNUhES3 was allowed to form EBs for two days, then EBs were induced to differentiate in the presence of a different serum concentration (EB and EB/high FBS group), or co-cultured with human BM stromal cells (EB/BM co-culture group). Flow cytometry and hematopoietic colony-forming assays were used to assess hematopoietic differentiation in the three groups. While no significant increase of CD34+/CD45- or CD34+/CD38- cells was noted in the three groups on days 3 and 5, the percentage of CD34+/CD45- cells and CD34+/CD38- cells was significantly higher in the EB/BM co-culture group than in the EB and EB/high FBS groups on day 10. The number of colony-forming cells (CFCs) was increased in the EB/BM co-culture group on days 7 and 10, implying a possible role for human BM stromal cells in supporting hematopoietic differentiation from human ES cell-derived EBs. These results demonstrate that co-culture of human ES-cell-derived EBs with human BM stromal cells might lead to more efficient hematopoietic differentiation from human ES cells cultured alone. Further study is warranted to evaluate the underlying mechanism
Treatment of Hodgkin's Disease: A Twenty-Year Follow-up of Patients at a Center in Korea
Hodgkin's disease (HD) is a hematologic malignancy which shows common features regardless of race, but racial differences may be considered with certain clinical characteritcs. HD in Korea shows somewhat different characteristics when compared to cases in Western countries. We evaluated the clinical and histopathologic characteristics of HD, the outcomes of various chemotherapy regimens, and prognostic factors of HD in Korea. One hundred and five patients with initial histopathologic diagnosis of Hodgkin's disease were retrospectively reviewed 20 years after diagnosis at Yonsei University College of Medicine. Nodular sclerosis was the most common histopathogic subtype (41%) and mixed cellularity was nearly as common (40%). The overall complete remission rate (CR) was 87.6%. The disease-free survival (DFS) and overall survival (OS) rate were 79.2% and 84.8% at 5-years, 70% and 79.2% at 10- and 20-years. There were no significant differences in CR rate and DFS, but OS rates were significantly higher in m-BACOP and ABVD regimen. Univariate analysis revealed that age, B-symptom, ECOG scale, Ann Arbor stage, international prognostic index, and serum Ī²2-microglobulin level were significant prognostic factors for both DFS and OS. Multivariate analysis demonstrated that age, B symptoms, and ECOG scale were significant prognostic factors for OS only. In conclusion, the survival rates of HD patients in our center were superior to those of previous reports in Korea and Western countries. Considering the higher OS rate and decreased incidence of side effects, the ABVD regimen may be recommended for the initial treatment of Hodgkin's disease
Blood amyloid-Ī² oligomerization associated with neurodegeneration of Alzheimers disease
Introduction
Oligomeric amyloid-Ć is a major toxic species associated with Alzheimers disease pathogenesis. Methods used to measure oligomeric amyloid-Ī² in the blood have increased in number in recent years. The Multimer Detection System-Oligomeric Amyloid-Ī² (MDS-OAĪ²) is a specific method to measure oligomerization tendencies in the blood. The objective of this study was to determine the association between amyloid-Ć oligomerization in the plasma and structural changes of the brain.
Methods
We studied 162 subjects composed of 92 community-based normal healthy subjects, 17 with subjective cognitive decline, 14 with mild cognitive impairment and 39 with Alzheimers disease dementia. All subjects underwent MDS-OAĪ² and three-dimensional T1 magnetic resonance imaging. To determine the structural changes of the brain that are statistically correlated with MDS-OAĪ² level, we used voxel-based morphometry with corrections for age and total intracranial volume covariates.
Results
We found brain volume reduction in the bilateral temporal, amygdala, parahippocampal and lower parietal lobe and left cingulate and precuneus regions (family-wise error, pā<ā0.05). Reduction was also found in white matter in proximity to the left temporal and bilateral lower parietal lobes and posterior corpus callosum (family-wise error, pā<ā0.05). Brain volume increment was not observed in any regions within grey or white matter.
Discussion
Findings suggest that substantial correlation exists between amyloid Ć oligomerization in the blood and brain volume reduction in the form of Alzheimers disease despite of uncertainty in the casual relationship.This work was supported by a grant of the Korea Healthcare Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (HI14C1251)
CSF total tau/Ī±-synuclein ratio improved the diagnostic performance for Alzheimers disease as an indicator of tau phosphorylation
Abstract
Background
Recently, several studies suggested potential involvements of Ī±-synuclein in Alzheimers disease (AD) pathophysiology. Higher concentrations of Ī±-synuclein were reported in cerebrospinal fluid (CSF) of AD patients with a positive correlation towards CSF tau, indicating its possible role in AD. We analyzed the CSF biomarkers to verify whether Ī±-synuclein could be an additional supported biomarker in AD diagnosis.
Methods
In this cross-sectional study, CSF samples of 71 early-onset AD, 34 late-onset AD, 11 mild cognitive impairment, 17 subjective cognitive decline, 45 Parkinsons disease, and 32 healthy control (HC) were collected. CSF amyloid-Ī²1-42 (A), total tau (N), and phosphorylated tau181 (T) were measured by commercial ELISA kits, and in-house ELISA kit was developed to quantify Ī±-synuclein. The cognitive assessments and amyloid-PET imaging were also performed.
Results
CSF Ī±-synuclein manifested a tendency to increase in AD and to decreased in Parkinsons disease compared to HC. The equilibrium states of total tau and Ī±-synuclein concentrations were changed significantly in AD, and the ratio of total tau/Ī±-synuclein (N/Ī±S) was dramatically increased in AD than HC. Remarkably, N/Ī±S revealed a strong positive correlation with tau phosphorylation rate. Also, the combination of N/Ī±S with amyloid-Ī²1-42/phosphorylated tau181ratio had the best diagnosis performance (AUCā=ā0.956, sensitivityā=ā96%, specificityā=ā87%). In concordance analysis, N/Ī±S showed the higher diagnostic agreement with amyloid-Ī²1-42 and amyloid-PET. Analysis of biomarker profiling with N/Ī±S had distinctive characteristics and clustering of each group. Especially, among the group of suspected non-Alzheimers disease pathophysiology, all AāT+N+ patients with N/Ī±S+ were reintegrated into AD.
Conclusions
The high correlation of Ī±-synuclein with tau and the elevated N/Ī±S in AD supported the involvement of Ī±-synuclein in AD pathophysiology. Importantly, N/Ī±S improved the diagnostic performance, confirming the needs of incorporating Ī±-synuclein as a biomarker for neurodegenerative disorders. The incorporation of a biomarker group [N/Ī±S] could contribute to provide better understanding and diagnosis of neurodegenerative disorders
Korean Type 2 Diabetes Patients have Multiple Adenomatous Polyps Compared to Non-diabetic Controls
We tested the correlation between diabetes and aggressiveness of colorectal polyps in diabetic patients and matched non-diabetic controls. We retrospectively studied 3,505 type 2 diabetes (T2DM) patients without gastrointestinal symptoms who underwent colonoscopy for colorectal cancer at Samsung Medical Center, Seoul, Korea from August 1995 to August 2009. We matched 495 non-diabetic subjects with colon polyps to the diabetic patients in whom polyps were detected by year of colonoscopy, age, sex and body mass index (BMI). Among the 3,505 T2DM patients screened, 509 were found to have 1,136 colon polyps. Those with diabetes had a greater proportion of adenomatous polyps (62.8% vs 53.6%) compared to the control. Multivariate logistic regression analysis identified DM, male gender, age and BMI as independent risk factors for multiple polyps (more than three polyps). Polyp multiplicity in diabetic patients was significantly associated with male gender (OR 2.360, P = 0.005), age (OR 1.033, P = 0.005) and BMI (OR 1.077, P = 0.028). Neither aspirin nor metformin use affected either size or number of polyps in diabetic patients. Male patients older than 65 yr with T2DM and BMI greater than 25 have increased risk for multiple adenomatous polyps and should be screened with colonoscopy to prevent colorectal cancer
Comparison of first-line treatment with CHOP versus ICED in patients with peripheral T-cell lymphoma eligible for upfront autologous stem cell transplantation
IntroductionUpfront autologous stem cell transplantation (ASCT) has been recommended for patients who are newly diagnosed with peripheral T-cell lymphoma (PTCL), and CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone), an anthracycline-based chemotherapy has been the frontline chemotherapy for PTCL. However, it is not clear whether anthracycline-based chemotherapies such as CHOP could be standard induction therapy for PTCL.MethodsWe conducted a randomized phase II study to compare CHOP with fractionated ifosfamide, carboplatin, etoposide, and dexamethasone (ICED) for patients eligible for ASCT. The primary endpoint was progression-free survival (PFS) and secondary endpoints included objective response rate, overall survival (OS), and safety profiles.ResultsPatients were randomized into either CHOP (n = 69) or ICED (n = 66), and the characteristics of both arms were not different. PTCL-not otherwise specified (NOS, n = 60) and angioimmunoblastic T-cell lymphoma (AITL, n = 53) were dominant. The objective response rate was not different between CHOP (59.4%) and ICED (56.1%), and the 3-year PFS was not different between CHOP (36.7%) and ICED (33.1%). In AITL patients, CHOP was favored over ICED whereas ICED was associated with more cytopenia and reduced dose intensity. Patients who received upfront ASCT after achieving complete response to CHOP or ICED showed 80% of 3-year OS.DiscussionIn summary, our study showed no therapeutic difference between CHOP and ICED in terms of response and PFS. Thus, CHOP might remain the reference regimen especially for AITL based on its better outcome in AITL, and upfront ASCT could be recommended as a consolidation of complete response in patients with PTCL
Epstein-Barr Virus-Positivity in Tumor has no Correlation with the Clinical Outcomes of Patients with Angioimmunoblastic T-cell Lymphoma
Clinical Features and Mutations in the ENG, ACVRL1, and SMAD4 genes in Korean Patients with Hereditary Hemorrhagic Telangiectasia
Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder that is characterized by abnormal communication between the arteries and veins in the skin, mucosa, and various organs. HHT has been reported to show significant phenotypic variability and genetic heterogeneity with wide ethnic and geographic variations. Although mutations in the endoglin (ENG) and activin A receptor type II-like 1 (ACVRL1) genes have been known to cause HHT for more than 10 yr, little is known about the clinical features or genetic background of Korean patients with HHT. In addition, mutations in mothers against decapentaplegic homolog 4 (SMAD4) are also seen in patients with the combined syndrome of juvenile polyposis and HHT. This study examined five Korean patients with the typical manifestations of HHT such as frequent epistaxis and pulmonary arteriovenous malformations. Direct sequencing of the ENG and ACVRL1 genes revealed one known mutation, ENG c.277C>T, in one patient and two novel mutations, ENG c.992-1G>C and ACVRL1 c.81dupT in two patients, respectively. The remaining two patients with negative results were screened for SMAD4 mutations as well as gross deletions of ENG and ACVRL1 using multiple ligation-dependent probe amplification, but none was detected. Despite the small number of patients investigated, we firstly report Korean patients with genetically confirmed HHT, and show the genetic and allelic heterogeneity underlying HHT
- ā¦