Dae Sik Kim

Hepatitis B virus reactivation in a surface antigen-negative and antibody-positive patient after rituximab plus CHOP chemotherapy.

Rituximab is a monoclonal antibody that targets B-lymphocytes, and it is widely used to treat non-Hodgkins lymphoma. However, its use has been implicated in HBV reactivation thats related with the immunosuppressive effects of rituximab. Although the majority of reactivations occur in hepatitis B carriers, a few cases of reactivation have been reported in HBsAg negative patients. However, reactivation in an HBsAg negative/HBsAb positive patient after rituximab treatment has never been reported in Korea. We present here an HBsAg-negative/HBsAb-positive 66-year-old female who displayed reactivation following rituximab plus CHOP chemotherapy for diffuse large B-cell lymphoma. While she was negative for HBsAg at diagnosis, her viral status was changed at the time of relapse as follows: HBsAg positive, HBsAb negative, HBeAg positive, HBeAb negative and an HBV DNA level of 1165 pg/ml. Our observation suggests that we should monitor for HBV reactivation during rituximab treatment when prior HBV infection or occult infection is suspected, and even in the HBsAg negative/HBsAb positive cases.

Bipolar Switching Behavior of ZnO x Thin Films Deposited by Metalorganic Chemical Vapor Deposition at Various Growth Temperatures

The bipolar resistive switching behaviors of ZnO films grown at various temperatures by metalorganic chemical vapor deposition have been investigated. The ZnO films were grown on Pt/Ti/SiO2/Si(100) substrate, and the ZnO growth temperature was varied from 300°C to 500°C in steps of 100°C. Rutherford backscattering spectroscopy analysis results showed that the chemical compositions of the ZnO films were oxygen-poor Zn1O0.9 at 300°C, stoichiometric Zn1O1 at 400°C, and oxygen-rich Zn1O1.3 at 500°C. Resistive switching properties were observed in the ZnO films grown at 300°C and 400°C. In contrast, high current, without switching properties, was found in the ZnO film grown at 500°C. The ZnO film grown at 500°C had higher concentration of both nonlattice oxygen (4.95%) and oxygen vacancy (3.23%) than those grown at 300°C or 400°C. The resistive switching behaviors of ZnO films are related to the ZnO growth temperature via the relative amount of oxygen vacancies in the film. Pt/ZnO/Pt devices showed asymmetric resistive switching with narrow dispersion of switching voltage.

Clinical Factors Related to Suspected Second Primary Lung Cancer Development in Patients with Head and Neck Cancer.

PURPOSEnThe rate of second primary lung cancer development for patients with head and neck cancer (HNC) has been noted. The aim of our study was to evaluate the incidence and clinical features of suspected second primary lung cancer that developed in patients with primary HNC.nnnMATERIALS AND METHODSnWe conducted a retrospective study of 469 patients who were newly diagnosed with HNC at the Korea University Medical Center between January 2000 and December 2006.nnnRESULTSnA total of 469 patients were included (389 men and 80 women). Eighteen patients (3.8%) had suspected second primary lung cancers. Statistically significant clinical variables for lung cancer development included the origin site for the primary HNC (oro-hypopharynx and larynx) (p=0.048), abnormal chest x-ray findings (p=0.027) and the histological HNC type (squamous cell carcinoma) (p=0.032). When the second primary lung cancers were combined with HNCs, the adjusted overall survival of patients with a second primary lung cancer was 16 months (p<0.001).nnnCONCLUSIONSnConsidering the relative risk factors for a second primary lung cancer developing in patients with HNC, advanced diagnostic tools, such as chest CT or PET CT scan, should be applied for the early detection of a second primary lung cancer.

Modified dose of melphalan-prednisone in multiple myeloma patients receiving bortezomib plus melphalan-prednisone treatment

Background/Aims Bortezomib plus melphalan-prednisone (VMP) is a standard treatment for multiple myeloma, particularly for patients who are ineligible for high-dose therapy. However, early discontinuation or treatment modification is often needed owing to adverse events. The aim of this study was to investigate the clinical outcomes of modifying the dose of melphalan-prednisone (MP) in patients receiving VMP. Methods We examined 67 patients who received a modified dose of MP, and 38 patients who received the regularly planned dose of MP. We then analyzed clinical differences between the groups. Results Although there was no difference in the proportion of discontinuation due to adverse events between dose groups, more patients in the planned-dose group experienced earlier discontinuation in general. The overall response rate (ORR) was 81.0% and complete response (CR) rate was 30.5%. After a median 15.7 months of follow-up, the median progression-free survival (PFS) and overall survival (OS) were 25.0 and 47.8 months, respectively. There was no significant difference in the ORR, CR, PFS, and OS of the two dose groups. A median of four cycles were delivered, and the median cumulative bortezomib dose was 41.6 mg/m2 . The median PFS in patients with doses ≥ 41.6 mg/m2 was longer than that in patients with doses < 41.6 mg/m2 (35.1 months vs. 9.6 months). However, when MP was < 50% of the planned dose, PFS and OS were poor. Conclusions Modifying the dose of MP might be a feasible and effective therapeutic approach for multiple myeloma patients receiving VMP treatment.

Lack of usefulness of computed tomography for surveillance in patients with aggressive non-Hodgkin lymphoma

Surveillance computed tomography (CT) is usual practice for patients with aggressive non-Hodgkin lymphoma (aNHL) in complete remission (CR). However, evidence to support this strategy is lacking. We retrospectively analyzed our institutional lymphoma registry, including patients with lymphoma consecutively enrolled from June 1995 to October 2016. Of 1,385 patients with aNHL, 664 achieved CR and were followed up with or without surveillance CT. Surveillance CT was performed for 609 patients every 3 or 6 months for the first 2 years, then every 6 or 12 months thereafter. Relapse was detected in 171 patients, of whom 152 underwent surveillance CT during follow-up. Of these 152 patients, asymptomatic relapse was detected in 67 (44%) using surveillance CT, and symptomatic relapse outside the surveillance interval was detected in the remaining 85 (56%). Detection of asymptomatic relapse using surveillance CT did not improve the overall or post-relapse survival in patients with relapsed aNHL. Surveillance CT interval (3 or 6 months) did not affect survival. No subgroups were identified that favored the use of surveillance CT to detect relapse. The results of this study suggest that routine surveillance CT in patients with aNHL to detect asymptomatic relapse might have a limited role in improving survival. CT is recommended when a relapse is clinically suspected.

The potential of exosomes derived from chronic myelogenous leukaemia cells as a biomarker

Background/Aim: Exosomes, derived from chronic myelogenous leukaemia (CML) cells, can be used as biomarkers and new targets for the detection of the BCR-ABL transcript. This study aimed to identify these possibilities. Materials and Methods: Human CML cell line-derived exosomes and CML-patients-derived exosomes were isolated with a size-exclusion chromatography column and ExoQuick™ exosome precipitation solution, respectively. Isolated exosomes were analysed by nested PCR to detect the BCR-ABL transcript. Results: Exosomes derived from the two human CML cell lines yielded a 250-bp band. RNA sequence analysis revealed 99% sequence homology with the partial mRNA for the human BCR-ABL chimeric protein. This ~250-bp band was also observed in the exosomes derived from patients with CML. However, only patients at the blast and accelerated phases showed the exosomal BCR-ABL transcript. Conclusion: CML-derived exosomes could act as novel targets for the detection of the BCR-ABL transcript.

GaN Film Growth Characteristics Comparison in according to the Type of Buffer Layers on PSS

【GaN is most commonly used to make LED elements. But, due to differences of the thermal expansion coefficient and lattice mismatch with sapphire, dislocations have occurred at about

Optical and Electrical Properties of ZnO Hybrid Structure Grown on Glass Substrate by Metal Organic Chemical Vapor Deposition

109{sim}1010/cm^2

Abstract 5113: Synergistic effects of Deferasirox and Imatinib in chronic myeloid leukemia cells

. Generally, a low temperature GaN buffer layer is used between the GaN layer and the sapphire substrate in order to reduce the dislocation density and improve the characteristics of the thin film, and thus to increase the efficiency of the LED. Further, patterned sapphire substrate (PSS) are applied to improve the light extraction efficiency. In this experiment, using an AlN buffer layer on PSS in place of the GaN buffer layer that is used mainly to improve the properties of the GaN film, light extraction efficiency and overall properties of the thin film are improved at the same time. The AlN buffer layer was deposited by using a sputter and the AlN buffer layer thickness was determined to be 25 nm through XRD analysis after growing the GaN film at

Growth and characterization of a multi-dimensional ZnO hybrid structure on a glass substrate by using metal organic chemical vapor deposition

1070^{circ}C