Sliding and rolling frictional behavior of a single ZnO nanowire during manipulation with an AFM.

The frictional behavior during manipulation of a single ZnO nanowire with a mass of about 18.7 ng placed horizontally on a Si wafer was examined using atomic force microscopy (AFM). The frictional force measured was in the range of 36.4 nN to 69.3 nN, which corresponded to extremely high friction coefficients of 242 and 462, respectively. However, when the adhesion force of the nanowire was considered, the friction coefficients were similar to the values typically encountered in macro-scale systems. During manipulation of the nanowire, both rolling and sliding motions were observed depending on the nanowire-Si frictional interaction. Unlike macro-scale systems, the difference between the frictional forces of rolling/sliding and pure sliding motions of the nanowire was not drastic.

A naturally derived gastric cancer cell line shows latency I Epstein-Barr virus infection closely resembling EBV-associated gastric cancer.

In a process seeking out a good model cell line for Epstein-Barr virus (EBV)-associated gastric cancer, we found that one previously established gastric adenocarcinoma cell line is infected with type 1 EBV. This SNU-719 cell line from a Korean patient expressed cytokeratin without CD19 or CD21 expression. In SNU-719, EBNA1 and LMP2A were expressed, while LMP1 and EBNA2 were not. None of the tested lytic EBV proteins were detected in this cell line unless stimulated with phorbol ester. EBV infection was also shown in the original carcinoma tissue of SNU-719 cell line. Our results support the possibility of a CD21-independent EBV infection of gastric epithelial cells in vivo. As the latent EBV gene expression pattern of SNU-719 closely resembles that of the EBV-associated gastric cancer, this naturally derived cell line may serve as a valuable model system to clarify the precise role of EBV in gastric carcinogenesis.

Lack of Association between Epstein-Barr Virus and Epithelial Malignancies Developed after Kidney Transplantation.

PURPOSE: Organ transplant recipients are at high risk of developing malignancies due to immunosuppressive regimens. Unlike post-transplant lymphoproliferative diseases (PTLDs), where Epstein-Barr virus (EBV) plays an etiological role, there are conflicting data regarding the association of EBV with post-transplant epithelial malignancies. In order to clarify the role of EBV in carcinomas that develop after solid-organ transplantation, the presence of EBV infection in the carcinomas of post-kidney transplant patients was examined. MATERIALS AND METHODS: The presence of EBV infection in skin carcinoma (PTSC), gastric carcinoma (PTGC) and urothelial carcinoma (PTUC), which developed in the patients under an immune suppression regime following kidney transplantation, was examined. Tumors from the patients without organ transplantation were also used as a comparison in the study. The study group included five nasopharyngeal carcinomas (NPCs), one Hodgkin's disease (HD), one B-cell non-Hodgkin's malignant lymphoma (NHL) and one hypopharynx (HPC) tumor. RESULTS: Immunofluorescence assay and Western blot analysis, using sera from the same patients, confirmed that all of the tested patients were previously infected with EBV. From in situ hybridization, no EBER positive cells were detected in any of the tumor tissues obtained from the three kidney transplant recipients (PTSC, PTGC and PTUC) or in the NHL and HPC tissues. In contrast, all five of the NPC and HD tissues showed strong EBER positivity. CONCLUSION: These results suggest that there is a strong association of EBV with NPC and HD as previously reported, while no such strong association of EBV was found with epithelial malignancies that developed after kidney transplantation.