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Biomedical subjects

T Ochi

Publications and source records attributed to T Ochi.

At least 127 records · Page 7Linked to original sources
PubMed1998

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

OBJECTIVE: To investigate the rheumatoid arthritis (RA)-specific autoantigen(s) recognized by CD4+ T cells in patients with RA. METHODS: CD4+,CD45RO+ T cell clones were established from the joints of RA patients, and were examined for their proliferative response to synovial cells. RESULTS: Eight 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. CONCLUSION: The 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.

Amino Acid Sequence↗
PubMed1998

Possible correction of abnormal rheumatoid arthritis synovial cell function by jun D transfection in vitro.

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic inflammatory disorder of joints, and excessive proliferation of and proinflammatory cytokine and collagenase production by synovial cells are a principal cause of joint destruction. Recent studies have revealed that c-jun and jun B promote growth of fibroblasts, whereas jun D suppresses fibroblast proliferation and even antagonizes Ras-mediated transformation of the fibroblasts. We analyzed effects of gene transfer-mediated jun D overexpression of synovial fibroblast-like cells in patients with RA. METHODS: RA synovial fibroblast-like cells were transiently transfected with jun D expression vector. The transfectants were stimulated with tumor necrosis factor alpha, and their subsequent proliferative responses and proinflammatory cytokine and matrix metalloproteinase (MMP) production at the messenger RNA and protein levels were measured. RESULTS: Transfection with jun D inhibited the proliferation of, and proinflammatory cytokine and MMP production by, RA synovial cells, mainly due to inhibiting their transcription via down-modulation of AP-1 transcription factor. CONCLUSION: Localized jun D transfection into the synovial cells of affected joints may inhibit aberrant synovial cell function in patients with RA by down-regulating gene transcription. This function suggests a possible clinical application of this gene therapy.

Arthritis, Rheumatoid↗
PubMed1998

Soluble Fas ligand in the joints of patients with rheumatoid arthritis and osteoarthritis.

OBJECTIVE: To investigate the expression and function of Fas ligand (FasL),which can be in a membrane-bound or soluble form, in the joints of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS: The concentration of soluble FasL (sFasL) in serum and synovial fluid (SF) from 24 OA and 38 RA patients was measured using an enzyme-linked immunosorbent assay. The expression of FasL on SF lymphocytes (SFL) and peripheral blood lymphocytes (PBL) was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. A cytotoxic killing assay of membrane-bound FasL and purified sFasL against cultured synovial cells was also performed. RESULTS: Soluble FasL was detected in the SF of patients with RA and OA, but not in their serum. The concentration of SF sFasL was remarkably higher in patients with severe RA than in patients with mild RA or with OA. RT-PCR showed that SFL, but not PBL, from RA patients expressed messenger RNA for FasL. Membrane-bound FasL induced apoptosis in cultured synovial cells from the RA and OA patients, but naturally processed human sFasL did not. CONCLUSION: SFL from RA patients expressed FasL, and cleaved sFasL accumulated in the SF of inflamed joints. The different killing activity of membrane-bound FasL and sFasL against synovial cells may regulate Fas-mediated apoptosis in synovial cells.

Aged↗
PubMed1998

Knee and/or hip joint destruction in rheumatoid arthritis is associated with HLA-DRB1*0405 in Japanese patients.

To determine the prognostic factors for knee and/or hip joint destruction in rheumatoid arthritis (RA) patients, we typed 379 RA patients for HLA-DRB alleles and analysed the antigen frequencies. The DRB1*0405 antigen frequency in RA patients who underwent total knee replacement and/or total hip replacement was significantly higher than in those who did not have replacements, which meant that DRB1*0405 was associated with knee and/or hip joint destruction. This finding may be of value for predicting knee and/or hip joint destruction in RA.

Adolescent↗
PubMed1998

Different effects of inorganic and dimethylated arsenic compounds on cell morphology, cytoskeletal organization, and DNA synthesis in cultured Chinese hamster V79 cells.

Changes in cytoskeletal organization of cultured V79 cells exposed to arsenite and dimethylarsinic acid (DMAA), a methylated derivative of inorganic arsenics, and related changes, such as mitotic arrest and induction of multinucleated cells, were investigated in comparison with their effects on DNA synthesis. DMAA caused mitotic arrest and induction of multinucleated cells with a delay of 12 h relative to the mitotic arrest. By contrast, arsenite at equitoxic concentrations to DMAA was less effective than DMAA in causing mitotic arrest and in inducing multinucleated cells. Post-mitotic incubation of cells arrested in metaphase by 6 h incubation with 10 mM DMAA showed that the incidence of multinucleated cells increased conversely with a rapid decrease in metaphase cells. This suggests that metaphase-arrested cells can escape from metaphase, resulting in the appearance of multinucleated cells. The mitotic arrest caused by DMAA was accompanied by disruption of the microtubule network. By contrast, both arsenite and DMAA did not cause disorganization of actin stress fibers even when incubated at concentrations that caused a marked retardation of cell growth. Cells exposed to arsenite for 6 h showed marked inhibition of DNA synthesis, whereas inhibition by DMAA was not observed. When incubation was prolonged by 18 h, the arsenite-induced inhibition of DNA synthesis was mitigated. By contrast, inhibition of DNA synthesis by DMAA occurred in parallel with an increase in the population of mitotic cells. These results suggest that DMAA caused growth retardation and morphological changes via disruption of the microtubule network, and that arsenite-induced retardation of cell growth and inhibition of DNA synthesis were not attributable to the cytoskeletal changes.

Animals↗
PubMed1998

Florid periosteal reaction and focal fibrocartilaginous dysplasia.

Focal fibrocartilaginous dysplasia (FFCD) is a rare condition causing tibia vara in childhood. It is characterized by progressive tibia vara in young children with a characteristic radiographic lesion. This paper is thought to be the first to describe FFCD exhibiting florid periosteal reaction at the time of presentation with a subtle faint osteolytic lesion in the diametaphysis of the proximal tibia.

Bone Diseases, Developmental↗
PubMed1998

Effect of alignment of the transplanted graft extracellular matrix on cellular repopulation and newly synthesized collagen.

This study examines the effect of alignment of the transplanted graft extracellular matrix on cellular repopulation and new collagen synthesis. The lateral half of the patellar tendon was harvested as a tendon graft from Lewis rats and frozen at -80 degrees C. In order to maintain the original alignment of the graft extracellular matrix, the graft was transplanted to a same size defect in the patellar tendon of other Lewis rats (group I). For controls, the graft was transplanted in a lax condition after excision of only the distal half of the lateral side of a patellar tendon (group II). After transplantation, six animals in each group were killed at 3, 7, 14, and 28 days. Cellular repopulation was assessed by using fibrillar-actin (F-actin) labeling with rhodamine-phalloidin, and new collagen synthesis was detected by means of a polyclonal antibody against type III collagen aminopropeptide (pN collagen III). Collagen fibril profiles were observed under the transmission electron microscope. On the 3rd day after transplantation, no specific fluorescence was detected in either group. Specific labeling for F-actin and pN collagen III, however, was observed at both ends of the graft in both groups at 1 week and throughout the graft at 2 weeks after transplantation. Consistent with the actin bundles' orientation, pN collagen III was aligned parallel to the longitudinal axis of the graft in group I. Collagen fibrils with a smaller diameter, mixed evenly and everywhere with a larger diameter, increased gradually in group I. However, smaller collagen fibrils in group II increased more slowly and were distributed unevenly. In summary, the dense collagen arrangement in the native patellar tendon determined the alignment of the repopulating cells, and the distribution of newly synthesized collagen might be affected by the actin cytoskeleton within the repopulating cells.

Actins↗
PubMed1998

Differential in situ expression of alpha2(XI) collagen mRNA isoforms in the developing mouse.

Type XI collagen is an essential structural component of the extracellular matrix of cartilage and plays a role in collagen fibril formation and skeletal morphogenesis. The expression of all three type XI collagen genes is not restricted to cartilage. In addition, alternative exon usage seems to increase the structural diversity and functional potential of type XI collagen during development. In order to investigate type XI collagen expression during development, we have examined alpha2(XI) and alpha1(XI) collagen genes by in situ hybridization in mice. Transcripts of the alpha2(XI) collagen gene were first detected in the notochord of mouse embryos after 11.5 days of gestation. Subsequently, alpha2(XI) mRNA was mainly found in the cartilaginous tissues of the developing limbs and axial skeleton together with transcripts of the alpha1(XI) gene. The alpha2(XI) transcripts seemed to be alternatively spliced isoforms lacking exons 6-8, which code for an acidic domain. Expression of alpha2(XI) outside the cartilage was relatively restricted, whereas expression of the alpha1(XI) gene was widespread. However, expression of alpha2(XI) transcripts containing exons 6-8 was found in non-chondrogenic tissues, including the calvarium and periosteum where intramembranous ossification occurs. These results indicate that alpha2(XI) mRNA isoforms are differentially expressed in various tissues during development. In addition, alpha2(XI) mRNA isoforms containing alternative exons are present in osteogenic cells, and their expression may be closely related to the formation of bone or cartilage.

Alternative Splicing↗
PubMed1998

Cloning and characterization of the murine P2XM receptor gene.

We have isolated the murine counterpart of the human P2XM gene (mP2XM), a P2X purinoceptor that is expressed predominantly in skeletal muscle. The mP2XM gene, consisting of 12 exons that span 10 kb of genomic DNA, encodes a 379-amino-acid product with 83% identity to the human homologue. Two potential transmembrane domains (M1 and M2) are present in the predicted product, and a segment resembling the H5 region of voltage-gated ion channels is completely conserved between human and mouse P2XM proteins. Predominant expression of mP2XM in murine skeletal muscle was confirmed by Northern-blot analysis, and a low level of expression was detectable in lung tissue, although human lung does not express P2XM.

Amino Acid Sequence↗
PubMed1998

Switch of osteonectin and osteopontin mRNA expression in the process of cartilage-to-bone transition during fracture repair.

The process of cartilage-to-bone transition (CBT) is a key event for the achievement of rigid bone healing during fracture repair. Since mineralization of cartilaginous matrix is a prerequisite for the initiation of CBT, the genetic localization of mineralization-related bone matrix proteins in CBT was examined in this study. An in situ hybridization method used on decalcified sections with digoxigenin-11-UTP labelled probes identified the cellular localizations of these genes in CBT. Cessation of osteonectin mRNA together with induction of osteopontin mRNA in chondrocyte maturation was observed during the process of CBT in the fracture callus on day 12 after fracture; osteocalcin mRNA was absent in chondrocytes of the CBT area. Induction of osteopontin mRNA in maturated chondrocytes was followed by the expression of mRNAs for osteonectin, osteopontin and osteocalcin in osteogenic cells in the ossification front of CBT. The data suggest that the switch from osteonectin to osteopontin mRNA expression in chondrocyte maturation is one of the key events during CBT. Transcriptional disorders of the expression of these molecules may be linked to the failure of fracture repair, i.e. delayed or prevented hypertrophic osteosynthesis.

Animals↗
PubMed1998

Alternative expression of Shc family members in nerve-injured motoneurons.

Expression of Shc family protein (Shc/ShcA, SCK/ShcB and N-Shc/ShcC) and Grb2 mRNAs in the hypoglossal motoneurons after axotomy was examined by in situ hybridization. In normal hypoglossal motor neurons, N-Shc mRNA was expressed predominantly, whereas the Shc mRNA level is very low. Rat hypoglossal nerve injury reversed the expressions of these two molecules in hypoglossal motoneurons. Shc mRNA expression was up-regulated markedly whereas N-Shc was down-regulated after nerve injury. Expression levels of SCK, another Shc family member, and Grb2 were unaffected by nerve injury. These results suggest that, whereas the N-Shc-mediated pathway dominates under normal conditions, an alternative Shc-mediated pathway is utilized in the event of nerve injury. By changing the expression of the Shc family members, the signaling pathway can be altered and various responses induced for nerve regeneration.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Colour Doppler analysis of tendon and muscle movements.

We have examined and successfully visualized active and passive movement of tendons and muscles using colour Doppler ultrasound. This preliminary study suggests that colour Doppler may be very useful to examine the movements of tendons and muscles.

Hand Injuries↗
PubMed1998

Articular cartilage evaluation in osteoarthritis of the hip with MR imaging under continuous leg traction.

We conducted MR evaluations of acetabular and femoral cartilages in 27 hips of patients with osteoarthritis and 10 hips of normal volunteers by a fat-suppressed three-dimensional (3D) pulse sequence using a continuous leg traction method, and correlated the results with radiographic assessment. Normal condition of the acetabular and femoral cartilages was clearly demonstrated in the normal volunteers. Grading of abnormalities was possible for each cartilage in the patients with osteoarthritis. In early osteoarthritis graded by radiography, a high prevalence of abnormalities was detected in the acetabular cartilage as compared with the femoral cartilage. Despite the structural difficulty in evaluation of the hip joint cartilage, our MR imaging technique can provide information concerning a wide spectrum of cartilage abnormalities even in the identical radiographic stage, which will lead to improvement in the evaluation of disease progression and in surgical planning.

Adult↗
PubMed1998

Early biological effect of in vivo gene transfer of platelet-derived growth factor (PDGF)-B into healing patellar ligament.

To define the early biological effect of in vivo introduction of the PDGF-B gene on the healing of ligaments, a HVJ-liposome suspension containing platelet-derived growth factor (PDGF)-B cDNA was injected directly into the injured patellar ligament of 14-week-old male Wistar rats. Rats were killed at 1, 4 and 8 weeks for the morphological analysis of angiogenesis by laminin immunohistochemistry and of collagen deposition by Masson's Trichrome staining and collagen I immunohistochemistry. PDGF-B gene transfer caused the enhanced expression of PDGF in healing ligament up to 4 weeks after transfection, leading to an initial promotion of angiogenesis and subsequent enhanced collagen deposition in the wound. Enhanced and accelerated matrix synthesis in the PDGF-B gene introduced healing ligament suggests that this gene transfer technique may be a potentially useful tool for improving soft tissue repair.

Animals↗
PubMed1998

A comparison of in vivo gene delivery methods for antisense therapy in ligament healing.

To determine the most efficient in vivo delivery method of oligonucleotides for antisense therapy in ligament healing, fluorescence-labelled phosphorothioate oligodeoxynuleotides (ODN) were introduced into 12 rabbit ligament scars 2 weeks after injury using haemagglutinating virus of Japan (Sendai virus: HVJ)-conjugated liposomes. We compared the efficiency of cellular uptake of fluorescence as a percentage of all cells in each scar using three delivery procedures: (1) direct free-hand injection into the ligament scar using a conventional syringe; (2) systematic direct sca injection using a repeating 10 microliters dispenser and a square mesh grid system; and (3) injection into the feeding (femoral) artery. Results showed that there was a significant difference in fluorescence uptake by scar cells on day 1 after injection between the three delivery methods: (1) direct free-hand, 9.7 +/- 7.6% (average +/- s.d.); (2) systematic direct, 58.4 +/- 15.9%; and (3) intra-arterial, 0.2 +/- 0.1%. Systematic direct injection was most efficient and it resulted in 25.9 +/- 13.0% of scar cells being labeled at 7 days after transfection. We then introduced antisense ODN for the rabbit proteoglycan, decorin, into ligament scars with this delivery method and confirmed a significant inhibition of decorin mRNA expression in antisense-treated scar tissues in vivo both at 2 days (42.3 +/- 14.7% of sense control +/- s.d.; P < 0.0025) and 3 weeks (60.5 +/- 28.2% of sense control +/- s.d.; P < 0.024) after treatment, compared with sense ODN-treated scars. Decorin was significantly suppressed also at protein level in antisense-treated scars at 4 weeks (66.6 +/- 35.7% of sense control +/- s.d.; P < 0.045) after treatment. These results demonstrate that in vivo transfection efficiency in ligament scars is 'delivery system dependent' and that introduction of antisense ODN for the small proteoglycan, decorin, with this delivery method can lead to significant suppression of its expression over 3 weeks both at mRNA and protein levels. Thus, an effective model for the potential manipulation of scar composition and quality in ligament healing has been established.

Animals↗
PubMed1998

An association between the natural course of shoulder joint destruction in rheumatoid arthritis and HLA-DRB1*0405 in Japanese patients.

To assess the association between HLA-DRB1 alleles and shoulder destruction due to rheumatoid arthritis (RA) in Japanese, we typed for HLA-DRB1 alleles in 100 Japanese RA patients who could be classified into 5 groups: non-progressive (N) with normal radiographs; erosive (E) showing marginal erosion but no collapse; collapse (C) showing subchondral cysts followed by collapse; arthrosis-like (A) showing osteoarthrotic features; and the mutilating (M) showing mutilating bone destruction. The HLA-DRB1*0405 antigen frequency in N, E, C, A, and M types was 55%, 61%, 33%, 71%, 100%, respectively. That in the M type (100%) was significantly higher than that in the others (the N, E, C, and A types; 57%). These findings suggest that the most severe shoulder joint destruction pattern in RA, the M type, is associated with HLA-DRB1*0405.

Adult↗
PubMed1998

The homozygote of HLA-DRB1*0901, not its heterozygote, is associated with rheumatoid arthritis in Japanese.

To assess the association between HLA-DRB1*0901 and Japanese rheumatoid arthritis (RA) patients, we analyzed the frequency of HLA-DRB1*0901 in 852 Japanese RA patients. We found that the homozygote of DRB1*0901 was associated with Japanese RA patients, while the heterozygote of DRB1*0901 was not. These findings suggest that DRB1*0901 is a weakly susceptible allele of RA, which in our investigation was not associated with RA by a single allele, but can be by a homozygote. DRB1*0901 does not have the shared epitope, and it is suggested that there may be some mechanism ofthe association between HLA-DRB1 and RA other than the shared epitope, which was not strong.

Alleles↗