Search PubMed⌕ Search

Biomedical subjects

R Teshima

Publications and source records attributed to R Teshima.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1998

Activation of protein kinase C alpha enhances human growth hormone-binding protein release.

The effect of phorbol ester on human growth hormone-binding protein (hGH-BP) release was investigated. The hGH-BP release from human IM-9 cells measured by immunoblotting was dose-dependently enhanced by a phorbol ester, phorbol 12, 13-dibutyrate (PDBu), and reached plateau at 100 nM. The increased hGH-BP release was shown after 10 min incubation with PDBu and reached a plateau at 60 min after stimulation. Similarly, a diacylglycerol analogue, 1-oleoyl-2-acetyl-sn-glycerol, enhanced hGH-BP release. The enhancement was not inhibited by cycloheximide pretreatment, suggesting that the enhanced hGH-BP release does not require de novo protein synthesis. The PDBu-enhanced hGH-BP release was strongly inhibited by extracellular EDTA, and was dose-dependently inhibited by protein kinase C (PKC)-specific inhibitor, Ro 31-8220. These results suggest that activation of PKC mediates the PDBu-enhanced hGH-BP release. Of the 11 known PKC isoforms in human cells, PKCalpha, delta, mu and iota were detected in IM-9 cells by immunoblotting. Of these isoforms, PKCalpha, delta and mu were present in the membrane fraction, which is a known activation marker of PKC. Furthermore, when several PKC-specific inhibitors (Gö 6976, GF 109203X or bisindolylmaleimide III) with different specificities for each isoform were used, there was a good correlation between inhibition of the enhancement of hGH-BP release and inhibition of the phosphorylation of PKC isoforms, another activation marker of PKC, in PKCalpha but not in PKCdelta and mu. These results suggest that activation of PKCalpha is involved in PDBu-enhanced hGH-BP release.

Carrier Proteins↗
PubMed1998

Simple spectrophotometric analysis of passive and active ear cutaneous anaphylaxis in the mouse.

Homologous passive cutaneous anaphylaxis (PCA) and active cutaneous anaphylaxis (ACA) to ovalbumin and DNP-hapten were studied in the ears of female BALB/c mice by means of assessing Evans blue dye leakage. For the quantitative evaluation of PCA and ACA, a hand-held spectrophotometer and the conventional colorimetric method were used to detect the amount of extravasated dye. The value of deltaE*ab (a numerical expression of color) obtained with the hand-held spectrophotometer and the amount of extravasated dye showed a good correlation. In the mouse ear, the sensitivity of PCA reaction was comparable to that of PCA in the rat, and deltaE*ab in the PCA and ACA reactions correlated well with the dilutions of sera and of the antigen, respectively. Thus, using a hand-held spectrophotometer is a simple, quantitative and sensitive method for ascertaining the extent of immediate-type hypersensitivity in the mouse.

Anaphylaxis↗
PubMed1998

Ca2+-ATPase inhibitors and PKC activation synergistically stimulate TNF-alpha production in RBL-2H3 cells.

OBJECTIVE AND DESIGN: To investigate the effect of Ca2+-ATPase inhibitors on the production of TNF-alpha in rat basophilic leukemia (RBL-2H3) cells. MATERIAL: Two Ca2+-ATPase inhibitors, thapsigargin (TG) and cyclopiazonic acid (CPA), and three hydroquinone-antioxidants, 2,5-di-(tert-butyl)-1,4-hydroquinone (DTBHQ), 2,5-di-(tert/amyl)-1,4-hydroquinone (DTAHQ), 2-(tertbutyl)-1,4-hydroquinone (MTBHQ) were used. TREATMENT: Cells were treated with TG, CPA, DTBHQ, DTAHQ and MTBHQ for 3 h in the presence of 12-Otetradecanoylphorbol-13-acetate (TPA) and released TNF-alpha from the cells was measured (n > or = 4). RESULTS: All Ca2--ATPase inhibitors (TG, CPA, DTBHQ and DTAHQ) induced TNF-alpha release in a dose-dependent manner. TNF-alpha release was inhibited by treatment with protein kinase C inhibitors (staurosporine, Ro31-8220, calophostin C) (p < or = 0.05). In contrast, MTBHQ, which does not induce increases in [Ca2+]i, did not induce the release of TNF-alpha. TNF-alpha release induced by DTBHQ and CPA was inhibited by treatment with actinomycin-D, the immunosuppressant FK506 and the glucocorticoid dexamethasone (p < or = 0.01). CONCLUSIONS: These results suggest 1) that [Ca2+]i increase and subsequent activation of protein kinase C is necessary for the release of TNF-alpha, and they work synergistically, 2) that the TNF-alpha release induced by Ca2+-ATPase inhibitors can be regulated at the transcriptional level.

Animals↗
PubMed1998

Radial and lumbar bone mineral density after wrist synovectomy in rheumatoid arthritis. A minimum 2-year follow-up in 10 unilaterally operated patients.

Bone mineral density (BMD) of both radii and lumbar vertebrae was measured by single-photon absorptiometry and dual X-ray absorptiometry, respectively, before and 2.1-4.8 years after a unilateral wrist synovectomy in 10 patients with rheumatoid arthritis. Radial BMD on the operated side significantly increased after synovectomy, while that on the non-operated side did not change. Lumbar BMD significantly decreased after the operation. The grip strength of the operated side increased significantly after synovectomy, while there were no changes in the grip strength on the non-operated side. These findings suggest that wrist synovectomy results in pain relief and improves use, thereby increasing the BMD of the operated radius.

Absorptiometry, Photon↗
PubMed1998

Ca2+-ATPase inhibitor induces IL-4 and MCP-1 production in RBL-2H3 cells.

The effects of a Ca2(+)-ATPase inhibitor, cyclopiazonic acid (CPA), and two hydroquinone-antioxidants, 2,5-di-(tert-butyl)-1,4-hydroquinone (DTBHQ) and 2,5-di-(tert-amyl)-1,4-hydroquinone (DTAHQ) on the release of IL-4 and MCP-1 from RBL-2H3 cells were investigated. CPA, DTBHQ and DTAHQ, all of which induce intracellular free Ca2+ concentration ([Ca2+]i) increase, induced IL-4 and MCP-1 release in a dose-dependent manner. The release of TNF-alpha required both a Ca2(+)-ATPase inhibitor and 12-O-tetradecanoylphorbol-13-acetate (TPA). However, the Ca2(+)-ATPase inhibitors induced IL-4 and MCP-1 production without TPA. The release of IL-4 and MCP-1 reached a maximum at 9 and 6 h, respectively. IL-4 and MCP-I release was inhibited by treatment with the immunosuppressant FK-506 and actinomycin D. Therefore, in our system IL-4 and MCP-1 release involves Ca2(+)-dependent and FK-506-sensitive signaling pathways. This is the first report about Th-2 type cytokine and chemokine production in RBL-2H3 cells.

Animals↗
PubMed1998

Soluble factors from rat basophilic leukemia (RBL-2H3) cells stimulated cooperatively the neurite outgrowth of PC12 cells.

Culture media from rat basophilic leukemia cells (RBL-2H3) induced the neurite outgrowth of rat pheochromocytoma PC12 cells, a model system for neuronal differentiation. The extension of the neurite outgrowth was dependent on the culture time of RBL-2H3 cells in the DMEM medium. The DMEM medium conditioned by RBL-2H3 cells for 48 h induced neurite outgrowth of PC12 cells significantly. The neurite extension was much higher than that by medium containing 1 ng/ml nerve growth factor (NGF) but was rather lower than that by medium containing 10 or 50 ng/ml NGF. The neurite extension by 50 ng/ml NGF was completely suppressed by excess anti-NGF antibody (1-1.5 microg/ml), while the extension by culture medium conditioned by RBL-2H3 cells for 48 h was not completely suppressed in the presence of the same amount of anti-NGF antibody. The neurite extension by the culture medium of RBL-2H3 cells was also suppressed by anti-interleukin (IL)-6 antibody (1 microg/ml), although IL-6 itself (20 units) could scarcely induce the neurite outgrowth of PC12 cells. This suggests that IL-6 in the culture medium of RBL-2H3 cells could be effective in inducing the neurite extension in cooperation with NGF. In the presence of an excess of both anti-NGF and anti-IL-6 antibodies, the culture medium of RBL-2H3 cells induced the neurite extension of PC12 cells. This suggests that the action of the various factors from RBL-2H3 cells may be synergistic as far as the neurite outgrowth of PC12 cells is concerned.

Animals↗