94 research outputs found
High resolution angle resolved photoemission studies on quasi-particle dynamics in graphite
We obtained the spectral function of the graphite H point using high
resolution angle resolved photoelectron spectroscopy (ARPES). The extracted
width of the spectral function (inverse of the photo-hole lifetime) near the H
point is approximately proportional to the energy as expected from the linearly
increasing density of states (DOS) near the Fermi energy. This is well
accounted by our electron-phonon coupling theory considering the peculiar
electronic DOS near the Fermi level. And we also investigated the temperature
dependence of the peak widths both experimentally and theoretically. The upper
bound for the electron-phonon coupling parameter is ~0.23, nearly the same
value as previously reported at the K point. Our analysis of temperature
dependent ARPES data at K shows that the energy of phonon mode of graphite has
much higher energy scale than 125K which is dominant in electron-phonon
coupling.Comment: 9 pages, 8 figures, accepted for publication in Phys. Rev.
Fixation Methods for Implantable Port Chamber: Comparative Study Using Glue, Self-stabilizing Leg and Suture Fixations in Rabbits
Autophagy deficiency leads to protection from obesity and insulin resistance by inducing Fgf21 as a mitokine
Despite growing interest and a recent surge in papers, the role of autophagy in glucose and lipid metabolism is unclear. We produced mice with skeletal muscle–specific deletion of Atg7 (encoding autophagy-related 7). Unexpectedly, these mice showed decreased fat mass and were protected from diet-induced obesity and insulin resistance; this phenotype was accompanied by increased fatty acid oxidation and browning of white adipose tissue (WAT) owing to induction of fibroblast growth factor 21 (Fgf21). Mitochondrial dysfunction induced by autophagy deficiency increased Fgf21 expression through induction of Atf4, a master regulator of the integrated stress response. Mitochondrial respiratory chain inhibitors also induced Fgf21 in an Atf4-dependent manner. We also observed induction of Fgf21, resistance to diet-induced obesity and amelioration of insulin resistance in mice with autophagy deficiency in the liver, another insulin target tissue. These findings suggest that autophagy deficiency and subsequent mitochondrial dysfunction promote Fgf21 expression, a hormone we consequently term a 'mitokine', and together these processes promote protection from diet-induced obesity and insulin resistance
Central Pontine Myelinolysis in a Patient with Acute Lymphoblastic Leukemia after Hematopoietic Stem Cell Transplantation: A Case Report
We describe a 37-yr-old man who developed central pontine myelinolysis (CPM) after allogeneic hematopoietic stem cell transplantation (HSCT) for acute lymphoblastic leukemia. After HSCT, desquamation developed on the whole body accompanied by hyperbilirubinemia. The liver biopsy of the patient indicated graft-versus-host disease-related liver disease, and the dose of methylprednisolone was increased. Then, the patient developed altered mentality with eye ball deviation to the left, for which electroencephalogram and magnetic resonance imaging (MRI) scans were done. Brain MRI scan demonstrated the imaging findings consistent with central pontine myelinolysis and extrapontine myelinolysis. He did not have any hyponatremia episode during hospitalization prior to the MRI scan. To the best of our knowledge, presentation of CPM after allogeneic HSCT is extremely rare in cases where patients have not exhibited any episodes of significant hyponatremia. We report a rare case in which hepatic dysfunction due to graft-versus-host disease has a strong association with CPM after HSCT
MCP-1 and RANTES Polymorphisms in Korean Diabetic End-Stage Renal Disease
Macrophage infiltration has been observed in the renal biopsy specimens of diabetic nephropathy (DN), and hyperglycemic state stimulates the renal expression of RANTES (regulated upon activation, normal T-cell expressed and secreted) and MCP-1 (monocyte chemoattractant protein-1). Upregulation of RANTES and MCP-1 with infiltrating macrophages may play a crucial role in the development and progression of DN. Genetic polymorphisms of RANTES and its receptors were reported to be independent risk factors for DN. We genotyped single nucleotide polymorphism (SNPs) in the MCP-1 G-2518A, CCR2 G46295A, RANTES C-28G and G-403A in 177 diabetic end-stage renal disease (ESRD) patients and 184 patients without renal involvement (controls) in order to investigate the effects of these SNPs on DN in Korean patients with type 2 DM. There were no differences in the frequencies of SNPs and the distribution of haplotypes of RANTES promoter SNPs between two groups. In conclusion, there were no associations of MCP-1, CCR2 and RANTES promoter SNPs with diabetic ESRD in Korean population. Prospective studies with clearly-defined, homogenous cohorts are needed to confirm the effect of these genetic polymorphisms on DN
Idarubicin Plus Behenoyl Cytarabine and 6-thioguanine Compares Favorably with Idarubicin Plus Cytarabine-based Regimen for Children with Previously Untreated Acute Myeloid Leukemia: 10-Year Retrospective, Multicenter Study in Korea
We investigated the outcome of idarubicin plus N4-behenoyl-1-β-D-arabinofuranosyl cytosine (BHAC)-based chemotherapy (BHAC group, n=149) compared to idarubicin plus cytarabine-based chemotherapy (cytarabine group, n=191) for childhood acute myeloid leukemia (AML). Between January 1996 and December 2005, 340 children with AML from 5 university hospitals in Korea received the BHAC-based or cytarabine-based chemotherapy, with or without hematopoietic stem cell transplantation. After induction therapy, 264 (77.6%) of 340 children achieved a complete remission (CR) and 43 (12%) achieved a partial remission (PR). The CR rate in the BHAC group was higher than in the cytarabine group (85.2% vs. 71.7%, P=0.004). However, the overall response rate (CR+PR) was not different between the two groups (93.3% vs. 87.9%, P=0.139). The 5-yr estimates of overall survival (OS) of children in the two groups were similar (54.9% for the BHAC group vs. 52.4% for the cytarabine group, P=0.281). Although the results were analyzed according to the treatment type and cytogenetic risk, the OS showed no significant difference between the BHAC group and the cytarabine group. In the present study, the clinical outcomes of the BHAC-based chemotherapy, consisting of BHAC, idarubicin, and 6-TG, are comparable to that of the cytarabine-based chemotherapy for childhood AML
The Mildly Elevated Serum Bilirubin Level is Negatively Associated with the Incidence of End Stage Renal Disease in Patients with IgA Nephropathy
Oxidative stress plays various roles in the development and progression of IgA nephropathy, while bilirubin is known as a potent antioxidant. We therefore hypothesized that serum bilirubin would be associated with renal prognosis in IgA nephropathy. The study subjects comprised 1,458 adult patients with primary IgA nephropathy in Korea. We grouped patients according to the following quartile levels of bilirubin: <0.4 mg/dL (Q1), 0.4-0.5 mg/dL (Q2), 0.6-0.7 mg/dL (Q3), and >0.8 mg/dL (Q4). The outcome data were obtained from the Korean Registry of end-stage renal disease (ESRD). Eighty patients (5.5%) contracted ESRD during a mean follow-up period of 44.9 months. The ESRD incidences were 10.7% in Q1, 8.2% in Q2, 2.8% in Q3, and 2.8% in Q4 (p<0.001). The relative risk of ESRD compared to that in Q1 was 0.307 (95% confidence interval [CI], 0.126-0.751) in Q3 and 0.315 (95% CI, 0.130-0.765) in Q4. The differences of ESRD incidence were greater in subgroups of males and of patients aged 35 yr or more, with serum albumin 4.0 g/dL or more, with normotension, with eGFR 60 mL/min/1.73 m2 or more, and with proteinuria less then 3+ by dipstick test. In conclusion, higher bilirubin level was negatively associated with ESRD incidence in IgA nephropathy
Efficacy of Tandem High-Dose Chemotherapy and Autologous Stem Cell Rescue in Patients Over 1 Year of Age with Stage 4 Neuroblastoma: The Korean Society of Pediatric Hematology-Oncology Experience Over 6 Years (2000-2005)
The efficacy of tandem high-dose chemotherapy and autologous stem cell rescue (HDCT/ASCR) was investigated in patients with high-risk neuroblastoma. Patients over 1 yr of age who were newly diagnosed with stage 4 neuroblastoma from January 2000 to December 2005 were enrolled in The Korean Society of Pediatric Hematology-Oncology registry. All patients who were assigned to receive HDCT/ASCR at diagnosis were retrospectively analyzed to investigate the efficacy of single or tandem HDCT/ASCR. Seventy and 71 patients were assigned to receive single or tandem HDCT/ASCR at diagnosis. Fifty-seven and 59 patients in the single or tandem HDCT group underwent single or tandem HDCT/ASCR as scheduled. Twenty-four and 38 patients in the single or tandem HDCT group remained event free with a median follow-up of 56 (24-88) months. When the survival rate was analyzed according to intent-to-treat at diagnosis, the probability of the 5-yr event-free survival±95% confidence intervals was higher in the tandem HDCT group than in the single HDCT group (51.2±12.4% vs. 31.3±11.5%, P=0.030). The results of the present study demonstrate that the tandem HDCT/ASCR strategy is significantly better than the single HDCT/ASCR strategy for improved survival in the treatment of high-risk neuroblastoma patients
Pre-Engraftment Syndrome after Unrelated Cord Blood Transplantation: A Predictor of Engraftment and Acute Graft-versus-Host Disease
AbstractPre-engraftment syndrome (PES) is poorly characterized, and its clinical significance and the prognostic impact after unrelated cord blood transplantation (CBT) are unclear. To address these issues, we retrospectively analyzed the incidence, risk factors, and clinical outcomes of PES in unrelated CBT recipients. Data of 381 patients who received unrelated CBT from 18 medical centers in Korea were reviewed. PES was defined as unexplained fever >38.3°C not associated with infection, and/or unexplained skin rash with or without evidence of fluid retention before neutrophil recovery. PES developed in 102 patients (26.8%) at a median of 7 days after CBT. Of these patients, 74 patients (72.5%) received intravenous corticosteroid at a median dose of 1 mg/kg/day, and of these, 95% showed clinical improvement. Risk factors for developing PES included low risk disease, myeloablative conditioning, graft-versus-host disease (GVHD) prophylaxis without methotrexate or corticosteroid, and >5.43 x 107/kg infused nucleated cells. Absence of PES was one of the risk factors for graft failure in multivariate analysis. The cumulative incidence of grade II to grade IV acute GVHD by 100 days after CBT was higher in patients with PES than in those without PES (56.0% versus 34.4%, P < .01). PES was not associated with chronic GVHD, treatment-related mortality, relapse, or overall survival. PES seems to be common after CBT and may be associated with enhanced engraftment without significant morbidity
Molecular diagnosis of hereditary spherocytosis by multi-gene target sequencing in Korea: matching with osmotic fragility test and presence of spherocyte
Background
Current diagnostic tests for hereditary spherocytosis (HS) focus on the detection of hemolysis or indirectly assessing defects of membrane protein, whereas direct methods to detect protein defects are complicated and difficult to implement. In the present study, we investigated the patterns of genetic variation associated with HS among patients clinically diagnosed with HS.
Methods
Multi-gene targeted sequencing of 43 genes (17 RBC membrane protein-encoding genes, 20 RBC enzyme-encoding genes, and six additional genes for the differential diagnosis) was performed using the Illumina HiSeq platform.
Results
Among 59 patients with HS, 50 (84.7%) had one or more significant variants in a RBC membrane protein-encoding genes. A total of 54 significant variants including 46 novel mutations were detected in six RBC membrane protein-encoding genes, with the highest number of variants found in SPTB (n = 28), and followed by ANK1 (n = 19), SLC4A1 (n = 3), SPTA1 (n = 2), EPB41 (n = 1), and EPB42 (n = 1). Concurrent mutations of genes encoding RBC enzymes (ALDOB, GAPDH, and GSR) were detected in three patients. UGT1A1 mutations were present in 24 patients (40.7%). Positive rate of osmotic fragility test was 86.8% among patients harboring HS-related gene mutations.
Conclusions
This constitutes the first large-scaled genetic study of Korean patients with HS. We demonstrated that multi-gene target sequencing is sensitive and feasible that can be used as a powerful tool for diagnosing HS. Considering the discrepancies of clinical and molecular diagnoses of HS, our findings suggest that molecular genetic analysis is required for accurate diagnosis of HS.Support was provided by: the National Research Foundation of Korea (NRF) grant funded by the Korea government(MSIT) (NRF-2017R1A2A1A17069780) http://www.nrf.re.kr/
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