Biomedical subjects

K Yudoh

Publications and source records attributed to K Yudoh.

46 records · Page 3Linked to original sources

PubMed1995

Laminectomy-induced arachnoradiculitis: a postoperative serial MRI study.

Time-related changes of laminectomy-induced cauda equina adhesions were investigated by MRI in ten patients with degenerative spinal disease who underwent posterior surgery to the lumbar spine; seven had disc herniations and three spinal stenosis. Axial MRI was performed before and 3, 7, 21 and 42 days after surgery. Cauda equina adhesions were most severe at the laminectomised levels L3-4, L4-5 and L5-S1 (n = 16); partial adhesions were found in 9 of 16 levels at 6 weeks after surgery. At the L3-4 or L5-S1 levels (n = 14), the area of laminar exposure without laminectomy, the cauda equina adhesions continued 1 week after surgery, but thereafter resolved; only partial adhesions were seen at 5 of 14 levels 6 weeks after surgery. Shrinkage of the arachnoid sac was also found at the level of the laminectomy, but it re-expanded 3 weeks after surgery in all cases. Cauda equina adhesions and shrinkage of the sac were correlated closely with laminectomy, with or without discectomy, suggesting that an inflammatory process of deep wound healing may be involved in the mechanism of a laminectomy-induced arachnoradiculitis which may be correlated with post-operative leg symptoms.

Adolescent↗

PubMed1995

Tumor cell attachment to laminin promotes degradation of the extracellular matrix and cell migration in high-metastatic clone cells of RCT sarcoma in vitro.

We investigated the roles of extracellular matrix proteins, laminin and fibronectin, in promoting invasiveness through the extracellular matrix in high-metastatic [RCT(+)] clone cells established from poorly differentiated murine RCT sarcoma in C3H/He mice. Laminin stimulated the type IV collagenolytic activity of RCT(+) cells. After more than 6 h of incubation, the type IV collagenolysis of the cell-conditioned medium was significantly higher in laminin-treated groups compared with the control. The migration activity of RCT(+) cells was stimulated by laminin. However, fibronectin did not influence the type IV collagenolysis or cell migration in this clone cell. The amino acid sequence YIGSR, which is derived from laminin, inhibited the laminin-mediated cell attachment and the laminin-promoted type IV collagenolysis, as well as cell migration of RCT(+) cells. RGD derived from fibronectin did not influence the cell attachment to laminin or Matrigel in this clone. In the invasion assay employing a Matrigel coated filter in a Boyden chamber, YIGSR showed greater inhibition of invasion through the Matrigel than did RGD with RCT(+) cells. YIGSR might inhibit the promoted-matrix degradation and cell migration in response to the cell attachment to laminin by competing with laminin for binding to cell surface laminin receptor. We suggest that laminin-mediated cell attachment to the extracellular matrix may play a role in promoting the matrix degradation and cell migration during metastatic cascades.

Amino Acid Sequence↗

PubMed1995

Solitary T-cell lymphoma of the sciatic nerve: case report.

In lymphoproliferative disorders, primary involvement of the peripheral nerve is rare. This report describes a very rare case of a solitary extranodal T-cell lymphoma of the sciatic nerve. Magnetic resonance imaging and gallium scintigraphy were useful for the identification of the lesion of the sciatic nerve. The histological analysis of an open-biopsy specimen disclosed a T-cell lymphoma (non-Hodgkin's lymphoma, lymphoblastic type). Radiotherapy and chemotherapy resulted in a partial regression of the disease.

Adult↗

PubMed1994

Calcitonin receptors on neoplastic mononuclear cells cultured from a human giant-cell tumor of the sacrum.

Saturable, specific, high-affinity calcitonin receptors were demonstrated in cultured neoplastic mononuclear spindle cells from a giant-cell tumor of the sacrum of a 38-year-old woman. The receptor was analyzed by autoradiography and 125I-calcitonin binding assay. Binding reversibility of 125I-calcitonin to the cells was not complete and the structural specificity was indicated by the inability of unrelated hormones to compete with calcitonin. The 24,000 receptors/cell and dissociation constant (Kd) of 8.0 x 10(-10) M, calculated from linear Scatchard plots, suggested the existence of a single class of calcitonin binding sites in the neoplastic mononuclear cells. Flow-cytometric analysis in the primary culture showed that mononuclear cells consisted of mononuclear round cells of monocyte/macrophage lineage, which express more calcitonin receptors than neoplastic mononuclear spindle cells. Administration of calcitonin caused morphological and physiological alterations, resulting in involutional or irregular cytoplasmic shapes and inhibition of DNA synthesis in neoplastic mononuclear cells accompanied by the escape phenomenon. Cells preincubated with calcitonin showed a decrease in 125I-calcitonin binding activity, which could account for the escape phenomenon. The decrease in 125I-calcitonin binding was rapid, but the recovery was not observed for 24 h after elimination of calcitonin. This decrease may be caused by the disappearance of residual receptors or by a decrease in calcitonin affinity. The calcitonin-induced morphological changes and the inhibition of DNA synthesis of cells were revealed to be mediated by calcitonin receptors.

Adult↗

PubMed1994

Effects of epidermal growth factor on invasiveness through the extracellular matrix in high- and low-metastatic clones of RCT sarcoma in vitro.

We investigated the invasiveness of tumor cells through the extracellular matrix and the influence of epidermal growth factor (EGF) on tumor cell invasion using in vitro systems in high-[RCT(+)] and low-metastatic [RCT(-)] clones established from poorly differentiated murine RCT sarcoma in C3H/He mice. In the invasion assay using a filter coated with reconstituted basement membrane (Matrigel) in a Boyden chamber, RCT(+) cells were more invasive than RCT(-) cells. The attachment of RCT(+) cells to extracellular matrix components and the degradation of type IV collagen by the cells were significantly greater than with RCT(-) cells. However, there was no significant difference in the migration of cells to the extracellular matrix components between cultured RCT(+) and RCT(-) cells. These findings suggested that the different invasiveness of these clone cells was associated with the difference in the ability of attachment to and degradation of the matrix. The level of laminin receptor expression in RCT(+) cells was about four-fold that in RCT(-) cells and laminin stimulated the type IV collagenolytic activity of RCT(+) cells, suggesting that RCT(+) cell attachment to laminin via laminin receptor on the cell surface induced the production of type IV collagenase by the tumor cells. EGF did not affect the invasiveness of RCT(-) cells. In RCT(+) cells, EGF stimulated the invasiveness through Matrigel, the attachment to extracellular matrix components and the degradation of type IV collagen through high-affinity EGF receptors (EGFR), with Kd of pM order, while the migration to the matrix was not influenced by EGF. These findings suggest that the stimulatory effect of EGF on invasion is related to the acceleration of cell adhesion, and the degradative cascade of the extracellular matrix and high-affinity EGFRs play an important role in the effect of EGF on in vitro invasiveness in this tumor.

Animals↗

PubMed1994

Serum levels of laminin, type IV collagen and type III procollagen peptide as markers for detection of metastasis.

We investigated the clinical usefulness of serum laminin, type IV collagen and type III procollagen peptide (PIIIP) as markers for detection of metastasis in patients with primary or metastatic bone and soft part tumors. The subjects consisted of 28 patients with metastatic bone tumors, 18 with primary bone tumors (benign; 10, malignant; 8), 22 with primary soft part tumors (benign; 12, malignant; 10), 18 with cancer without metastasis (as controls to metastatic bone tumor) and 60 healthy controls. Elevated levels of serum laminin, type IV collagen and PIIIP were not associated with any specific histological subtype, tumor size or location, and were clearly related to evidence of metastasis. Mean serum concentrations of laminin, type IV collagen and PIIIP were significantly higher in patients with metastasis than in patients without metastasis. Positive correlations were observed among serum laminin, type IV collagen and PIIIP levels in tumor patients. The sensitivity values for laminin, type IV collagen and PIIIP in detecting metastasis were 83.7%, 83.3% and 80.5%, respectively, with specificity of 90.0%, 86.1% and 86.1%. When two of the three markers were evaluated in identical blood samples, combined sensitivity and specificity values exhibited further increases as compared to the sensitivity and specificity of each marker. The use of all three markers led to the best combined sensitivity and specificity. These findings suggest that the combination of these markers would be a valuable screening test in predicting metastasis.

Analysis of Variance↗

PubMed1993

Differentiation of Dunn osteosarcoma cells in response to dibutyryl cyclic 3',5'-adenosine monophosphate.

We investigated the effects of dibutyryl cyclic adenosine 3',5'-monophosphate (Bt2cAMP) on the differentiation of Dunn osteosarcoma cells. Flow-cytometric analysis and DNA synthesis assay showed that Bt2cAMP decreased the cell population in the S phase in a time- and dose-dependent manner. Also, the cells showed distinct morphological and functional alterations; the cell morphology changed to a fibroblast-like appearance with long and thin protoplasmic processes, the knobs or blebs on both the cell membrane and nuclear membrane disappeared and the intracellular alkaline phosphatase activity increased. Moreover, Bt2cAMP-treated cells secreted a large quantity of fibronectin, which was deposited on the extended cell surface in the culture medium. Thus, Dunn osteosarcoma cells are differentiated morphologically and functionally by Bt2cAMP, and might be transformed to benign precursor cells.

Alkaline Phosphatase↗

PubMedDate not supplied

Effects of tumor cell-derived interleukin 1 alpha on invasiveness of metastatic clones of murine RCT sarcoma through endothelial cells.

Interleukin 1 alpha (IL-1alpha) production and invasiveness through mouse lung endothelial cells (MLE) were investigated in high-metastatic RCT+ and low-metastatic RCT- clones established from poorly differentiated murine sarcoma. Apparently, a higher level of IL-1alpha was derived from RCT+ cells than from RCT- cells. In an invasion assay, the number of cells which penetrated the MLE monolayer in RCT+ was significantly greater than that in RCT-. The invasiveness of RCT+ and RCT- cells was stimulated by additional recombinant mouse IL-1alpha (rIL-1alpha) in a dose-dependent manner. Anti-mouse IL-1alpha monoclonal antibody (anti-IL-1alpha mAb) significantly inhibited the invasiveness of RCT+ and RCT- cells through the MLE monolayer. However, in RCT+ cells these effects were higher than in RCT- cells. In an attachment assay, the ability of RCT+ cells to attach to the MLE monolayer was significantly higher than that of RCT- cells. The attachment ability of RCT+ and RCT- cells to the MLE monolayer was significantly increased by the pretreatment with rIL-1alpha in a dose-dependent manner. In a retraction assay, conditioned medium of RCT+ stimulated the retraction of the MLE monolayer more markedly in comparison with conditioned medium of RCT-. The retraction of the MLE monolayer was stimulated by additional rIL-1alpha in a dose-dependent manner. The increased retraction of the MLE monolayer was closely associated with the enhancement in tumor cell invasiveness. These findings suggest that IL-1alpha derived from RCT+ and RCT- cells might contribute to the enhancement of tumor cell invasion by stimulating the attachment to the MLE monolayer and retraction of the MLE monolayer.

Animals↗

PubMedDate not supplied

Effects of vascular endothelial growth factor and E-selectin on angiogenesis in the murine metastatic RCT sarcoma.

The relationship between vascular endothelial growth factor (VEGF) and induction of angiogenesis in high-metastatic RCT(+) or low-metastatic RCT(-) clones of the poorly differentiated murine RCT sarcoma was investigated. The association with E-selectin in VEGF-induced angiogenesis was also evaluated. RCT(+) cells produced significantly larger amounts of VEGF than RCT(-) cells. In a tube formation assay with murine lung microvascular endothelial (MLE) cells, conditioned medium from RCT(+) cells showed a significantly greater effect on tube formation than that from RCT(-) cells. Induction of tube formation was suppressed by anti-mouse VEGF monoclonal antibody. Furthermore, anti-mouse E-selectin monoclonal antibody suppressed the tube formation induced by recombinant mouse VEGF. In a flow-cytometric analysis, the expression of E-selectin on MLE cells was upregulated after pretreatment with conditioned medium from RCT(+) and RCT(-) cells. Conditioned medium from RCT(+) cells induced a higher expression of E-selectin compared to medium from RCT(-) cells. Anti-VEGF monoclonal antibody prevented the upregulation of E-selectin by the RCT cell-conditioned medium. These findings suggest that E-selectin plays an important role in the angiogenesis induced by VEGF. VEGF derived from tumor cells may enhance angiogenesis by upregulating the expression of E-selectin on vascular endothelial cells.

Animals↗

PubMedDate not supplied

Corticosteroid treatment induces chondrocyte apoptosis in an experimental arthritis model and in chondrocyte cultures.

OBJECT: In order to examine the mechanisms involved in steroid-induced arthropathy after intra-articular corticosteroid injection, a histological examination was performed in vivo using severe combined immunodeficiency (SCID) mice that were implanted with human articular cartilage into the back (SCID/hu model). In addition, the effect of corticosteroids on chondrocyte apoptosis was evaluated in vitro using cultured human chondrocytes. METHOD: Human articular cartilage was obtained during knee surgery and implanted subcutaneously into the backs of SCID mice. One month later, weekly injections of corticosteroid (hydrocortisone acatate: 1 mg/0.2 ml, triamcinolone acetonide: 0.2 mg/0.2 ml, dexamethasone acetate: 0.1 mg/0.2 ml) in the subcutaneous cavity around the grafted cartilage in SCID mice were initiated. After six weeks of treatment, the grafted cartilage pieces were removed from the SCID mice and examined histologically. Chondrocyte apoptosis after corticosteroid treatment was also investigated using cultured human chondrocytes. RESULT: In the corticosteroid treated, grafted articular cartilage, apoptotic chondrocytes were apparent in the superficial and middle layers of cartilage. But a reduced intensity of Safranin O staining was not remarkable. In the cultured chondrocytes, apoptotic changes were also observed after corticosteroid treatment. CONCLUSION: Corticosteroid treatment induces chondrocyte apoptosis and it may be important to understand the steroid-induced arthropathy.

Animals↗