Ryuji Suzuki

Establishment and characterization of nurse cell-like stromal cell lines from synovial tissues of patients with rheumatoid arthritis

OBJECTIVEnTo investigate the features of synovial stromal cells established from patients with rheumatoid arthritis (RA), and to define these cells as nurse cells.nnnMETHODSnSynovial nurse-like stromal cell lines (RA-SNCs) were established from patients with RA. These cell lines were examined for morphology, pseudoemperipolesis activity, cell surface markers, and cytokine production. The interaction between these RA-SNCs and a synovial tissue B cell clone was also examined.nnnRESULTSnRA-SNCs had nurse cell activity. They spontaneously produced interleukin-6 (IL-6), IL-8, granulocyte colony-stimulating factor, and granulocyte-macrophage colony-stimulating factor. Furthermore, they produced IL-1beta and tumor necrosis factor alpha and expressed higher levels of the other cytokines after coculture with the B cell clone. Proliferation and Ig production by the B cell clone were dependent on direct contact with RA-SNCs.nnnCONCLUSIONnThese results indicate that the RA-SNCs were nurse cells. The findings suggest that RA-SNCs may play an important role in the pathogenesis of RA by producing large amounts of cytokines and maintaining infiltrating lymphocytes.

Zonal Gene Expression of Chondrocytes in Osteoarthritic Cartilage

OBJECTIVEnTo determine the chondrocyte metabolism in respective zones of osteoarthritic (OA) cartilage.nnnMETHODSnOA cartilage was obtained from macroscopically intact areas of 4 knee joints with end-stage OA. The cartilage was divided into 3 zones, and gene expression profiles were determined in the respective zones by a custom-designed microarray that focused on chondrocyte-related genes. For the genes whose expression was significantly different among the zones, the expression was compared between OA and control cartilage in the respective zones by an analysis using laser capture microdissection and real-time polymerase chain reaction (PCR). For some genes, the correlation of expression was investigated in specific cartilage zones.nnnRESULTSnA total of 198 genes (approximately 40% of those investigated) were found to be expressed at significantly different levels among the zones. Expression of 26 of those genes was evaluated by laser capture microdissection and real-time PCR, which confirmed the validity of microarray analysis. The expression of cartilage matrix genes was mostly enhanced in OA cartilage, at similar levels across the zones but at different magnitudes among the genes. The expression of bone-related genes was induced either in the superficial zone or in the deep zone, and positive correlations were found among their expression in the respective zones. The expression of 5 proteinase genes was most enhanced in the superficial zone, where their expression was correlated, suggesting the presence of a common regulatory mechanism(s) for their expression.nnnCONCLUSIONnIn OA cartilage, the metabolic activity of chondrocytes differed considerably among zones. Characteristic changes were observed in the superficial and deep zones.

MOIRCS: Multi-Object Infrared Camera and Spectrograph for the Subaru Telescope

MOIRCS (Multi-Object InfraRed Camera and Spectrograph) is one of the second generation instruments for the Subaru Telescope. This instrument is under construction by the National Astronomical Observatory of Japan and Tohoku University. It has imaging and multi-object spectroscopy (MOS) capabilities in the wavelength range from 0.85 μm to 2.5 μm with 4 x 7 F.O.V. The focal plane is imaged onto two 2048 x 2048 pixel HAWAII-2 HgCdTe arrays with a pixel scale of 0.12 pixel-1 through two independent optical trains. The optical design is optimized to maximize K band performance. Unique design of MOIRCS allows multi-object spectroscopy out to K band with cooled multi-slit masks. Twenty-four masks are stored in a mask dewar and are exchanged in the cryogenic environment. The mask dewar has its own vacuum pump and cryogenic cooler, and the masks can be assessed without breaking the vacuum of the main dewar. The two-channel optics and arrays are mounted back-to-back of a single optical bench plate. A PC-Linux based infrared array control system has been prepared to operate HAWAII-2. The first light of MOIRCS is planned in the spring of 2003.

Tohoku University Focal Plane Array Controller (TUFPAC)

TUFPAC (Tohoku University Focal Plane Array Controller) is an array control system originally designed for flexible control and efficient data acquisition of 2048 x 2048 HgCdTe (HAWAII-2) array. A personal computer operated by Linux OS controls mosaic HAWAII-2s with commercially available DSP boards installed on the PCI bus. Triggered by PC, DSP sends clock data to front-end electronics, which is isolated from the DSP board by photo-couplers. Front-end electronics supply powers, biases and clock signals to HAWAII2. Pixel data are read from four outputs of each HAWAII2 simultaneously by way of four channel preamps and ADCs. Pixel data converted to 16 bit digital data are stored in the frame memory on the DSP board. Data are processed in the memory when necessary. PC receives the frame data and stores it in the hard disk of PC in FITS format. A set of the DSP board and front-end electronics is responsible for controlling each HAWAII-2. One PC can operate eight mosaic arrays at most. TUFPAC is applicable to the control of CCDs with minor changes of front-end electronics.

Recognition of rheumatoid arthritis synovial antigen by CD4+,CD8- T cell clones established from rheumatoid arthritis joints.

OBJECTIVEnTo investigate the rheumatoid arthritis (RA)-specific autoantigen(s) recognized by CD4+ T cells in patients with RA.nnnMETHODSnCD4+,CD45RO+ T cell clones were established from the joints of RA patients, and were examined for their proliferative response to synovial cells.nnnRESULTSnEight of 146 T cell clones responded to RA synovial cells in a DR-restricted manner. These T cell clones recognized solubilized antigens extracted from RA synovial cells in the presence of DR-matched antigen-presenting cells, but did not respond to those extracted from non-RA synovial cells. The antigens had a molecular weight of 50/25 kd. Five of the 8 T cell clones used T cell receptor BV6, and the remaining clones used BV12.2.nnnCONCLUSIONnThe antigens recognized by joint-infiltrating CD4+ T cells are present exclusively in RA synovial cells. The expression of these antigens by synovial cells may trigger the autoreactivity of T cells in RA joints.

Optical design of MOIRCS

We describe an optical design process and image performance evaluations for Multi-Object near-InfraRed Camera and Spectrograph (MOIRCS). MOIRCS is a near-infrared imager and multi-object spectrograph under construction for the Subaru Telescope. MOIRCS provides direct imaging of 4 x 7 F.O.V. with a pixel scale of 0.12. MOIRCS also provides low-resolution multi-object spectroscopy with grisms and cooled multi-slit masks on the Cassegrain focal plane. CaF2, BaF2, ZnSe, and Fused Silica are used as the lens materials. They have high transmission in the near-infrared wavelength. During the design process, we find that a triplet with an achromatic doublet and a ZnSe singlet shows good performance for chromatic aberration. Therefore, we design our optics on the basis of the triplet with ZnSe. The designed optics shows good performances. Ensquared energy within 2 pixel square is more than 85% over the entire wavelength range and F.O.V. We do not need refocusing with the change of observed wavelengths because chromatic aberration is as small as 100 μm by the triplet with ZnSe over the entire wavelength range from 0.85 to 2.5 μm. Lateral chromatic aberration of 15 μm is less than 1 pixel size. Detailed tolerance analysis is done with possible manufacturing and aligning errors considered. The result shows that designed performances will be kept with a probability of 80% with reasonable tolerances. Ghost analysis is also done over entire F.O.V. and we find a ghost image of 13 magnitude fainter than original image that is not significant for our purpose. Therefore, we conclude that we can obtain enough performances with designed optics.