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R Teshima

Publications and source records attributed to R Teshima.

At least 19 recordsLinked to original sources
PubMed2000

A screening method for antigen-specific IgE using mast cells based on intracellular calcium signaling.

A simple screening method is presented for the measurement of antigen-specific IgEs in sera in which mast cells are used. This method is based on the intracellular calcium signal in mast cells induced by cross-linking the surface high-affinity Fc receptors (FcepsilonRIs) with IgEs and multivalent antigens. When a serum containing various antigen-specific IgEs is added to the mast cell suspension, various antigen-specific IgEs are captured by FcepsilonRIs on the cell surface. However, the required antigen-specific IgE can be specifically detected after the addition of the corresponding antigen. The resulting increase in intracellular calcium concentration ([Ca2+]i), monitored by Ca2+-fluorometry, was found to be an analytical measure for the screening of IgEs. Two kinds of rodent mast cells, cell-lined RBL2H3 cells and primary cultured BMMCs, were used as a representative model system of mast cells. A DNP hapten (DNP35-HSA) and ovalbumin (OVA) were chosen for illustrative antigens, and these antigen-specific IgEs (DNP-specific IgE, OVA-specific IgE) in the corresponding rodent sera were target antibodies. It was found that [Ca2+]i increased linearly with IgE concentrations ranging from 25 to 5000 ng/mL for DNP-specific IgE and from 5 to 50 ng/mL for OVA-specific IgE. For these dynamic ranges, optimum concentrations of antigens were found to be 10 ng/mL and 1 microg/mL for DNP35-HSA and OVA, respectively. It was concluded that by monitoring the increase of [Ca2+]i in mast cells, we could determine the antigen-specific IgEs. The present immunological assay based on the Ca2+ signal transduction in mast cells offers new possibilities for efficient screening of antigen-specific IgEs and the immunogenicity of IgE in sera.

Animals↗
PubMed2000

Clinicoradiologic study of cervical laminoplasty with posterolateral fusion or bone graft.

STUDY DESIGN: A retrospective study of cervical expansive laminoplasty for cervical myelopathy from a clinicoradiologic perspective. OBJECTIVE: To clarify the correlation among sagittal curvature of the cervical spine, cervical range of motion, sagittal plane translation, spinal cord atrophy, and myelopathic symptoms in patients who have undergone laminoplasty. SUMMARY OF BACKGROUND DATA: Laminoplasties were developed to diminish the undesirable effects of laminectomy, which include postoperative kyphotic changes and instability. However, the superiority of laminoplasty over laminectomy remains controversial. METHODS: Fifty-one patients with cervical spondylotic myelopathy or ossification of the cervical posterior longitudinal ligament who underwent laminoplasty were radiologically assessed before and after surgery. The index of the sagittal curvature, intervertebral range of motion, listhesis, and the transverse area of the spinal cord at the site of maximal compression were measured to evaluate interrelations among those parameters and myelopathic symptoms. RESULTS: There were no patients with kyphotic curvature before surgery. The postoperative curvature tended to be less lordotic. This tendency did not adversely affect postoperative symptoms. The intervertebral range of motion was significantly decreased except at C1-C2. The final C4-C5 range of motion and the postoperative myelopathic symptoms were negatively correlated. A significant correlation was observed between the postoperative spinal cord atrophy and the final myelopathic symptoms. CONCLUSIONS: The decrease in the lordotic curvature index and the decrease in the intervertebral range of motion after laminoplasty did not cause neurologic deterioration. In the C4-C5 intervertebral segment with a high incidence of listhesis, the restriction of the C4-C5 range of motion improved the clinical myelopathic symptoms. The radiologic prognostic factors were the postoperative restriction of intervertebral range of motion in preoperatively unstable segments and the anatomic reversibility of spinal cord insult.

Aged↗
PubMed2000

Identification of 142 single nucleotide polymorphisms in 41 candidate genes for rheumatoid arthritis in the Japanese population.

Single-nucleotide polymorphisms (SNPs) can make an important contribution to our understanding of genetic backgrounds that may influence medical conditions and ethnic diversity. We undertook a systematic survey of genomic DNA for SNPs located not only in coding sequences but also in non-coding regions (e.g., introns and 5' flanking regions) of selected genes. Using DNA samples from 48 Japanese patients with rheumatoid arthritis (RA) as templates, we surveyed 41 genes that represent candidates for RA, screening a total of 104 kb of DNA (30 kb of coding sequences and 74 kb of non-coding DNA). Within this 104 kb of genomic sequences we identified 163 polymorphisms (1 per 638 bases on average), of which 142 were single-nucleotide substitutions and the remainder, insertions or deletions. Of the coding SNPs, 52% were non-synonymous substitutions, and non-conservative amino acid changes were observed in a quarter of those. Sixty-nine polymorphisms showed high frequencies for minor alleles (more than 15%) and 20 revealed low frequencies (<5%). Our results indicated a greater average distance between SNPs than others have reported, but this disparity may reflect the type of genes surveyed and/or the relative ethnic homogeneity of our test population.

Alleles↗
PubMed2000

Effect of Ca(2+) ATPase inhibitors on MCP-1 release from bone marrow-derived mast cells and the involvement of p38 MAP kinase activation.

The effect of two Ca(2+) ATPase inhibitors, cyclopiazonic acid (CPA) and 2,5-di-(tert-butyl)-1,4-hydroquinone (DTBHQ), on the release of MCP-1 from bone marrow-derived mast cells (BMMCs) were investigated. CPA and DTBHQ increased the intracellular free Ca(2+) concentration ([Ca(2+)](i)) and induced MCP-1 release in a dose-dependent manner. These Ca(2+) ATPase inhibitors induced MCP-1 release in the absence of phorbol ester, in contrast to their induction of TNF-alpha. MCP-1 release reached a maximum at 6-9 h. It was inhibited by treatment with actinomycin D, the immunosuppressant cyclosporin A, and the cytosolic Ca(2+) chelator BAPTA-AM. Furthermore, RT-PCR showed a time-dependent increase of MCP-1 mRNA. Thus MCP-1 release seems to depend on Ca(2+)-dependent transcriptional activation. MCP-1 release was dose-dependently inhibited by the p38 MAP kinase inhibitor SB202190, but not by the p44/42 MAP kinase inhibitor PD98059. Therefore, transcriptional activation of MCP-1 production and its release seem to be dependent on the nuclear factor of activated T cells and p38 MAP kinase activation. This is the first report to show the regulation of MCP-1 production in BMMCs.

Animals↗
PubMed1999

Direct neurite-mast cell communication in vitro occurs via the neuropeptide substance P.

Communication between nerves and mast cells is a prototypic demonstration of neuroimmune interaction. However, whether mast cell activation occurs as a direct response to neuronal activation or requires an intermediary cell is unclear. Addressing this issue, we used an in vitro coculture approach comprising cultured murine superior cervical ganglia and rat leukemia basophilic cells (RBLs; possesses properties of mucosal-type mast cells). Following loading with the calcium fluorophore, Fluo-3, neurite-RBL units (separated by <50 nm) were examined by confocal laser scanning microscopy. Addition of bradykinin, or scorpion venom, dose-dependently elicited neurite activation (i.e., Ca2+ mobilization) and, after a lag period, RBL Ca2+ mobilization. Neither bradykinin nor scorpion venom had any direct effect on the RBLs in the absence of neurites. Addition of a neutralizing substance P Ab or a neurokinin (NK)-1 receptor antagonist, but not an NK-2 receptor antagonist, dose-dependently prevented the RBL activation that resulted as a consequence of neural activation by either bradykinin or scorpion venom. These data illustrate that nerve-mast cell cross-talk can occur in the absence of an intermediary transducing cell and that the neuropeptide substance P, operating via NK-1 receptors, is an important mediator of this communication. Our findings have implications for the neuroimmune signaling cascades that are likely to occur during airways inflammation, intestinal hypersensitivity, and other conditions in which mast cells feature.

Animals↗
PubMed1999

Role of ecto-kinase in phorbol ester-enhanced growth hormone-binding protein release from human IM-9 cells.

Previously we reported that a phorbol ester, phorbol 12, 13-dibutyrate (PDBu), increased the release of human growth hormone-binding protein (hGH-BP) in IM-9 cells, and that this phorbol ester-enhanced release was mediated by protein kinase Ca (PKCalpha). In the present study, the mechanisms of the phorbol ester-enhanced hGH-BP release were further investigated. Treatment of IM-9 cells with PDBu did not increase hGH-BPs (55-60 kDa) in the intracellular soluble fraction. When the cells were treated with trypsin to remove human growth hormone receptors (hGHRs) on the cell surface after stimulation, no hGH-BPs were detected in the culture supernatants, nor did treatment with bafilomycin A1 or chloroquine affect the PDBu-enhanced hGH-BP release. These results suggest that hGH-BPs released by PDBu stimulation are derived from cell surface hGHRs and not generated within the cells. Protein kinase inhibitors with broad specificities, K-252a and K-252b, inhibited the PDBu-enhanced release with almost the same dose-dependency, although only a trace amount of K-252b was incorporated into IM-9 cells than K-252a, suggesting that K-252b probably inhibits an ecto-kinase extracellularly. PDBu actually enhanced the phosphorylation of several extracellular proteins, and this enhanced phosphorylation was completely inhibited by K-252b treatment. Moreover, the PKCalpha-specific inhibitor bisindolylmaleimide III which inhibits PDBu enhanced hGH-BP release inhibited the PDBu-enhanced phosphorylation of extracellular proteins. On the other hand, the impermeable PKC inhibitor PKC inhibitor peptide 19-31 did not inhibit PDBu-enhanced release, suggesting that the target PKCalpha for PDBu is not present on the extracellular surface. Taken together, these results suggest that, in addition to intracellular PKCalpha, activation of an undefined ecto-kinase may also be involved in the PDBu-enhanced hGH-BP release.

Carbazoles↗
PubMed1999

Casein kinase II-like ectokinase activity on RBL-2H3 cells.

We studied the properties of the ectokinase activity on the outer cell surfaces of RBL-2H3 cells and examined the phosphorylation of exogenous substrates to clarify the substrate specificity of the ectokinases on RBL-2H3 cells. Among the several protein substrates tested, casein was the most strongly phosphorylated with [gamma-32P]ATP, and the net incorporation of 32P into casein was 0.65 pmol P/50 microg/10(6) cells. Casein kinase II peptide was also phosphorylated with [gamma-32P]ATP. The phosphorylation of casein and casein kinase II peptide was almost completely inhibited by the addition of 3 microg/ml of cell-impermeable K252b. Phosphorylation of casein and casein kinase II peptide was also observed by [gamma-32P]GTP. Western blot analysis using anti-casein kinase II antibody revealed a 44-kDa casein kinase band in the membrane fraction and Fc epsilonRI complexes. The immunofluorescence microscopic analysis using anti-casein kinase II antibody showed the existence of casein kinase II on the surface of the cells. This is the first report about the existence of ectokinase on mast cells.

Animals↗
PubMed1999

Suppression of calcium oscillation by tri-n-butyltin chloride in cultured rat hepatocytes.

The effects of tri-n-butyltin chloride (TBT), an environmental pollutant, on cytoplasmic free calcium ion concentration ([Ca2+]i) were investigated in primary cultured rat hepatocytes. A high concentration (4.0 microM) of TBT increased resting levels of [Ca2+]i and then induced cell blebs resulting in cell death within 2 h. The increase in [Ca2+]i, but not the cell death, depended on the presence of extracellular Ca2+, suggesting that the increase in [Ca2+]i is not critical for the cytotoxicity of TBT. A low concentration (0.1 microM) of TBT did not have any toxic effect (decrease in ATP content, decrease in viability, and shape change) on cultured hepatocytes and did not change [Ca2+]i. However, the calcium responses induced by phenylephrine, [Arg8]-vasopressin, and ATP were suppressed in the cells pretreated with 0.1 microM TBT for 30 min. The suppression was not observed in the cells pretreated with 0.1 microM TBT for only 1 min. Pretreatment with 0.1 microM TBT for 30 min had no effect on the inositol 1,4,5-triphosphate content or its increase in response to hormonal stimulation. These results suggest that TBT suppresses hormone-induced calcium responses at nontoxic low concentrations.

Animals↗
PubMed1999

Magnetic resonance imaging of meniscal degeneration in torn menisci: a comparison between anterior cruciate ligament deficient knees and stable knees.

Signal anomalies observed in magnetic resonance imaging of the intrameniscal tissue adjacent to the tear were compared between stable knees (group 1, 54 menisci) and anterior cruciate ligament (ACL) deficient knees (group 2, 98 menisci). The histological significance of these signal anomalies was also studied (n = 25). The frequency of intrameniscal signal anomalies adjacent to the tear was significantly lower in ACL-deficient knees than in ACL-stable knees (P = 0.0022). There was a close correlation between the imaging anomalies and the presence of histological lesions (fissures, degeneration) within meniscal tissues adjacent to the tear (sensitivity: 0.95, specificity: 0.60). Our results suggest that the severity of intrameniscal degenerative changes adjacent to the tear are lower in ACL-deficient knees than in ACL-stable knees.

Adolescent↗
PubMed1999

Anomalies of ossification in the posterolateral femoral condyle: assessment by MRI.

BACKGROUND: Anomalies of ossification in the lower femoral epiphysis are often radiographically indistinguishable from juvenile osteochondritis dissecans. OBJECTIVE: To clarify the MRI characteristics of the anomalies of ossification in the posterolateral femoral condyle that distinguish it from juvenile osteochondritis dissecans. MATERIALS AND METHODS: We retrospectively examined the medical records, plain radiographs (n = 4), MRI (n = 4) and follow-up MRI (n = 2) of four boys (age 8-11 years) with anomalies of ossification in the posterolateral femoral condyle. RESULTS: Plain radiography showed symmetrical marginal irregularity of the posterolateral femoral condyles of both knees. These lesions were asymptomatic, and the areas of irregular radiographic appearances reduced in size or disappeared without treatment within a mean observation period of 3.5 months. MRI showed a clearly demarcated low-intensity islet with the same signal intensity as subchondral bone (which was considered to be an accessory ossification nucleus) in a high-signal area in which the signal intensity was equal to that of normal articular cartilage. The areas observed as radiolucent zones on plain radiography were visualised at the same signal intensity as articular cartilage, and were continuous with articular cartilage on MRI; thus they were regarded as uncalcified cartilage. These MR findings are different from MR images of osteochondritis dissecans. CONCLUSIONS: MRI is considered to be the most effective non-invasive diagnostic method for these two conditions.

Child↗
PubMed1999

Discoid lateral menisci in older patients. A radiographic study of 21 cases.

Twenty-three knees of 21 patients over 40 years of age with discoid lateral menisci were examined by radiography. The mean age of the patients was 59.7 years (range: 40-78 years). No patient had symptoms before the age of 40 and only 12 knees gave symptoms from the lateral compartment, although tears of a discoid lateral meniscus were diagnosed by arthrography in 21 of the 23 knees. Varus inclination occurred more frequently than valgus inclination. Subchondral bone sclerosis was more common in the medial compartment. However, high incidences of marginal osteophytes in the lateral compartment and morphological anomalies (cupping or flattening) of the lateral tibial plateau were revealed by radiography.

Adult↗
PubMed1999

The change of bone mineral density in secondary osteoporosis and vertebral fracture incidence.

Causes of secondary osteoporosis are diverse, and bone changes in this condition have been elucidated less than those in primary osteoporosis. In this study, bone mineral density (BMD) was measured in the lumbar spine, distal and proximal sites of the radius, and calcaneus in representative disorders that cause secondary osteoporosis to evaluate its changes. Also, the incidence of nontraumatic vertebral fracture was examined. The subjects were 80 patients with rheumatoid arthritis, 50 patients undergoing glucocorticoid (steroid) therapy, 20 patients with chronic hepatitis, 24 patients with liver cirrhosis, 14 patients with primary biliary cirrhosis (PBC), 26 patients with diabetes mellitus, and 20 postgastrectomy patients; all were ambulatory female outpatients. Two hundred females with primary osteoporosis were examined as a control group. The reproducibility of the measurement of the BMD was satisfactory at about 3% by all methods of measurement employed. Concerning changes in BMD, periarticular trabecular bone density was most markedly reduced in the rheumatoid arthritis group. The patients receiving steroid therapy showed the greatest decreases in the trabecular bone mineral density at the distal 4% of the radius and lumbar spinal BMD. In addition, the threshold of vertebral fracture was higher in those undergoing steroid therapy than in those with primary osteoporosis. The patients with PBC showed the greatest decreases in BMD among patients with chronic liver disorders, and no decrease in BMD was noted in the chronic hepatitis group. BMD was reduced only in the radius in the patients with diabetic mellitus, and it was generally reduced in the postgastrectomy patients. BMD of the calcaneus was not reduced in any group.

Adrenal Cortex Hormones↗
PubMed1999

Radiological pathogenesis of cervical myelopathy in 60 consecutive patients with cervical ossification of the posterior longitudinal ligament.

STUDY DESIGN: The radiological pathogenetic factors for cervical myelopathy in 60 consecutive patients with cervical ossification of the posterior longitudinal ligament (OPLL) were investigated retrospectively. OBJECTIVE: To clarify which patients with OPLL will develop cervical myelopathy. METHODS: Sixty consecutive patients with OPLL were radiologically assessed comparing the myelopathic patient group (M group, n=41) and the mild or non-myelopathic patient group (non-M group, n=19). RESULTS: The narrowing ratio of the spinal canal in the M group (47.1%) was significantly greater (P=0.026) than that in the non-M group (38.3%). The two groups showed a significant difference (P=0.0016) with regard to the Pavlov ratio (M group, 0.73; non-M group, 0.84). The total range of motion of the cervical spine did not differ between the two groups but the per cent range of motion was significantly greater (P=0.037) in the M group than in the non-M group. CONCLUSION: This study suggests that factors important in the onset or aggravation of myelopathy are factors related to pathological compression by OPLL, cervical soft disc herniation, developmentally narrow spinal canal, and local or non-proportional hypermobility.

Adult↗
PubMed1999

The effect of feeding carrots on immunoglobulin E production and anaphylactic response in mice.

Carrot juice was administered orally to BALB/c mice immunized intraperitoneally with dinitrophenylated (DNP)-OVA for about 1 month. The titers of DNP-specific IgE, DNP-specific IgG, and the levels of total IgE in mouse sera were determined. The DNP-specific IgE production by mice fed carrot juice was significantly inhibited. On the other hand, the DNP-specific IgG production and the level of total IgE in mice fed carrot juice were not significantly different from those in control mice. We also examined the effect of feeding carrots on immediate-type hypersensitivity. One hour after antigen stimulation, the ears of mice fed carrots swelled less than those of control mice. Furthermore, the rise in serum histamine in the mice fed carrots under active systemic anaphylaxis was lower than in controls. We then examined the pattern of cytokine production by spleen cells from mice followed by restimulation with DNP-OVA in vitro. The spleen cells from the mice fed carrots produced more interferon-gamma than those from the control group. In contrast, the spleen cells from the mice fed carrots produced less interleukin-4 than those from the control group. Furthermore, the interleukin-12 production of the spleen cells from mice fed carrots was also higher than that of the control group. These findings suggest that feeding carrots improves the helper T cell (Th)1/Th2 balance, inhibiting specific IgE production and antigen-induced anaphylactic response.

Anaphylaxis↗
PubMed1999

Anterior-posterior knee laxity increased by exercise. Quantitative evaluation of physiologic changes.

To quantify physiologic changes in anterior-posterior laxity of the normal knee caused acutely by exercise, we evaluated the exercise level and the duration of exercise needed to cause changes in laxity, the magnitude of changes in laxity, and the time needed for laxity to return to the level before exercise, by continuously applying a fixed exercise load. After a 20-minute run at 7 km/hr, anterior laxity with a displacement force of 133 N increased by about one third, and the compliance increased by one half with anterior drawer between 0 and 67 N. These changes were maintained at a similar level during exercise. The levels before exercise were restored gradually over 1 hour after exercise. As the muscle strength showed no changes during exercise, we consider these changes in laxity are not associated with a decrease in muscle strength. Furthermore, since the changes in knee laxity after triathlon (in which the knee is subjected to prolonged excessive exercise) are similar to those after running at 7 km/hr, we believe that the magnitude of changes in laxity after exercise is fixed, regardless of the level of the exercise load. Moreover, the threshold of exercise that causes the maximum change is low.

Adult↗
PubMed1999

Effects of weight bearing on the tidemark and osteochondral junction of articular cartilage: histomorphometric analyses of 7 normal femoral heads.

To study the effect of weight bearing on the tidemark and osteochondral junction, we compared the morphology of these two boundaries in weight-bearing and less weight-bearing regions of normal human femoral heads. We measured the irregularities of the boundaries in the two regions using an X-Y digitizer connected to a computer in histological whole sections of femoral heads in 7 subjects without joint diseases. The irregularity of the tidemark was small, showing no difference between the two regions. However, the irregularity of the osteochondral junction in the weight-bearing region was greater than in the less weight-bearing region, which was confirmed by three-dimensional reconstructed images. Our findings suggest that mechanical stresses greatly influence the morphology of the osteochondral junction compared to the influence of such stresses on the tidemark, and that the marked irregularity of the osteochondral junction in the weight-bearing region is a reactive phenomenon against mechanical fragility due to simple contact between calcified cartilage and subchondral bone without fibrous connections.

Aged↗