Biomedical subjects

Yuji Takeda

Publications and source records attributed to Yuji Takeda.

12 recordsLinked to original sources

PubMed2003

Expression of GPI-80, a beta2-integrin-associated glycosylphosphatidylinositol-anchored protein, requires neutrophil differentiation with dimethyl sulfoxide in HL-60 cells.

GPI-80 is a member of the amidohydrolase family that has been proposed as a potential regulator of beta2-integrin-dependent leukocyte adhesion. GPI-80 is expressed mainly in human neutrophils. Our previous studies suggested that GPI-80 expression might be associated with myeloid differentiation. To verify this, we examined whether GPI-80 is expressed on the human promyelocytic leukemia cell line HL-60 following treatment with differentiation inducers. GPI-80 expression was induced in cells treated with dimethyl sulfoxide (DMSO) to stimulate differentiation down the neutrophil pathway. On the other hand, all-trans-retinoic acid (ATRA), another neutrophil-inducing reagent, induced no clear GPI-80 expression. Potent monocyte-inducing reagents such as 1alpha,25-dihydroxyvitamin D(3) or phorbol 12-myristate 13-acetate also had no significant effect on the protein expression. GPI-80-positive cells were found in the well-differentiated CD11b-positive and transferrin-receptor-negative cell population. Granulocyte colony-stimulating factor, which augments neutrophil differentiation of HL-60 cells, up-regulated GPI-80 expression in the presence of DMSO. Granulocyte/macrophage colony-stimulating factor, which is known to suppress the neutrophil maturation of cells, inhibited expression. Adhesion of DMSO-induced cells was regulated by anti-GPI-80 monoclonal antibody, similar to the regulation observed in neutrophils. These results suggest that use of DMSO to induce neutrophil differentiation provides suitable conditions for GPI-80 expression, and that this culture system may be a helpful model for further study of the regulation of GPI-80 expression during myeloid differentiation.

Amidohydrolases↗

PubMed2003

Off-pump coronary artery bypass grafting in octogenarians.

OBJECTIVES: Off-pump coronary artery bypass grafting (CABG) has become accepted for myocardial revascularization because it reduces perioperative morbidity. We assessed the safety and efficacy of bypass surgery on the beating heart in elderly patients. METHODS: Off-pump CABG was done in 25 patients aged 80 years or older between February 1996 and February 2001. We retrospectively compared clinical results for these patients to those of 18 consecutive age-matched patients undergoing on-pump CABG during the same period. RESULTS: Mean patient age in both groups was similar--82.2 +/- 2.3 years in the off-pump group vs 81.9 +/- 2.0 years in the on-pump group (p = 0.66). Preoperative risk was similar in both groups, but significantly more patients in the on-pump group had triple-vessel disease. Distal anastomoses were significantly fewer in the off-pump group than in the on-pump group at 2.0 +/- 1.0 vs 2.8 +/- 0.5 (p < 0.01). The off-pump group had a shorter postoperative ventilation--13.4 +/- 17.2 hours vs 45.2 +/- 52.8 hours (p < 0.05)--, and less blood transfused--16% vs 89% (p < 0.01)--than the on-pump group. Mean postoperative hospitalization and intensive care unit stay were 18.6 days and 3.2 days in the off-pump group, versus 37.1 days and 9.4 days in the on-pump group (p < 0.05). No difference was seen in the incidence of major postoperative complications between groups. No hospital deaths occurred in the off-pump group. CONCLUSION: Off-pump CABG is thus a safe and effective for myocardial revascularization in the elderly.

Aged↗

PubMed2003

Active gene expression of a xyloglucan endotransglucosylase/hydrolase gene, XTH9, in inflorescence apices is related to cell elongation in Arabidopsis thaliana.

Regulation of cell wall structure plays a central role in growth and differentiation in plants. Xyloglucan endotransglucosylase/hydrolases (XTHs) that catalyze the cleavage and molecular grafting of xyloglucan chains function in loosening and rearrangement of the cell wall. We have characterized XTH9, a member of the XTH family that was isolated by systematic differential screening for highly expressed genes in shoot apices in Arabidopsis. In the vegetative phase, XTH9 transcripts accumulate in the shoot apex region. In the reproductive phase, transcript levels in shoot apices increase further, and they also are detected in flower buds, flower stalks and internodes bearing flowers. XTH9 expression levels were reduced markedly in mutants such as acl which are characterized by short internodal cell lengths, but recover at permissive temperatures in the temperature-sensitive acl mutants. Differential expression of XTH9 along the inflorescence stem was also detected in pin1 where no lateral organs are formed. These observations suggest that XTH9 expression is coordinated with plant development, including the differentiation from vegetative and reproductive meristems and cell elongation of the inflorescence stem.

Amino Acid Sequence↗

PubMed2003

Studies on the mechanisms of leukocyte adhesion to cellulose acetate beads: an in vitro model to assess the efficacy of cellulose acetate carrier-based granulocyte and monocyte adsorptive apheresis.

Granulocyte and monocyte adsorptive apheresis (GMA) using a column filled with cellulose acetate (CA) beads (carriers) has been associated with a significant clinical efficacy in patients with rheumatoid arthritis and ulcerative colitis. To obtain further understanding on the mechanisms of disease modification by cellulose acetate-carrier-based GMA, in the present study, we investigated the mechanisms of granulocyte and monocyte adhesion to CA beads following exposure of human peripheral blood to the carriers at 37 degrees C for up to 60 min under controlled conditions. Cellulose acetate beads selectively adsorbed granulocytes, monocytes. CD19+ (B cells) and CD56+ (NK cells) lymphocyte subpopulations. The granulocyte and monocyte adsorption was inhibited by heat-inactivated plasma and EDTA, indicating that the adsorption was plasma protein (immunoglobulin, complement) and calcium dependent. Accordingly, granulocyte and monocyte adsorption was markedly enhanced by coating the carriers with IgG. Similarly, C3b was adsorbed onto the CA beads as a marker of complement activation. The results indicated that IgG and active complement fragments mediated leukocyte adhesion to CA beads via the FcgammaR and/or leukocyte complement receptor like CR3. Additionally, CA beads induced loss of expression of TNF receptors on CD16- granulocytes and CD14+ monocytes, but not on CD3+ lymphocytes In conclusion, CA beads might be an appropriate biomaterial for inducing extracorporeal immunomodulation as a treatment for auto-immune diseases which are associated with pathological leukocyte activity.

Blood Component Removal↗

PubMed2003

Localization of GPI-80, a beta2-integrin-associated glycosylphosphatidyl-inositol anchored protein, on strongly CD14-positive human monocytes.

Human monocyte/macrophage systems are extremely heterogeneous. Although many attempts have been made to define monocyte subpopulations, few antigens distinguish them. We previously reported that GPI-80, a novel glycosylphosphatidyl-inositol (GPI)-anchored protein that is expressed mainly on human neutrophils regulates neutrophil adherence and migration, and that GPI-80 is expressed on monocytes. In this study, we examined the precise distribution of GPI-80-positive monocytes using flow cytometry. Using anti-CD14 and anti-CD16 mAbs, almost all GPI-80-bearing monocytes belong to the strongly CD14-positive monocyte subpopulation. Furthermore, flow cytometric analysis of GPI-80 and other monocyte markers revealed that GPI-80 expression was high in CD11b-, CD32-, and CD64-positive monocytes. In contrast, GPI-80 expression was low in HLA-DQ-positive monocytes. These results suggest that almost all GPI-80 positive monocytes belong to a monocyte subpopulation that is superior in phagocytosis and reactive oxygen production, but inferior in antigen presentation. GPI-80 may be a useful antigen for classifying monocytes into subpopulations.

Amidohydrolases↗

PubMed2003

Glycosylphosphatidyl inositol-anchored protein (GPI-80) gene expression is correlated with human thymoma stage.

Thymoma is one of the most common solid tumors in the mediastinum. Because there is no typical cell line for human thymoma, the development and use of molecular-based therapy for thymoma will require detailed molecular-genetic analysis of patients' tissues. Recent reports showed that genetic aberrations in thymoma were most frequently seen in chromosome 6q regions. We investigated the use of oligonucleotide arrays to monitor in vivo expression levels of genes in chromosome 6 regions in early- (stage I or II) and late- (stage IVa) stage thymoma tissues from patients. These in vivo gene expression profiles were verified by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) using LightCycler for 48 thymoma patients and sandwich ELISA for 33 thymoma patients. Using both methods, a candidate gene was identified which was overexpressed in stage IV thymoma. This was a known glycosylphosphatidyl inositol (GPI)-anchored protein (GPI-80), which is highly homologous with Vanin-1, a mouse thymus homing protein. Serum level of GPI-80 was confirmed to be elevated in stage IV thymoma compared with in stage I thymoma by using sandwich ELISA. The combined use of oligonucleotide microarray, real-time RT-PCR, and ELISA analyses provides a powerful new approach to elucidate the in vivo molecular events surrounding the development and progression of thymoma.

Amidohydrolases↗

PubMed2002

Assessment of ascending aorta using epiaortic ultrasonography during off-pump coronary artery bypass grafting.

BACKGROUND: Use of an aortic partial clamp for proximal anastomosis during off-pump coronary artery bypass is known to increase the risk of fatal complications. The purpose of this study was to assess the management of the ascending aorta evaluated with epiaortic ultrasonography during off-pump coronary artery bypass. METHODS: Intraoperative ultrasonography of the ascending aorta with a 10-MHz probe was performed consecutively in 155 patients undergoing off-pump coronary artery bypass between August 1999 and July 2001. The findings from ultrasonography, surgical modifications, and operative results were analyzed. RESULTS: In 54 patients (34.8%), epiaortic ultrasonography showed atherosclerotic findings in the anterior side of the ascending aorta (group A). The remaining 101 patients had either normal findings or atherosclerotic findings in only the posterior side (group NA). A proximal anastomosis to the aorta was preoperatively planned in 117 patients (group A, 42; group NA, 75). In group A, a graft modification without clamping was implemented in 29 patients (24.8% of 117 patients), whereas the clamp site was modified to a different segment in 13 patients (11.1% of 117 patients). In all 75 patients in group NA, partial clamping was used in the standard fashion. There were no cerebral infarctions or operative deaths related to partial clamping. However, aortic dissection occurred in 1 patient in group NA. CONCLUSIONS: In 35% of patients undergoing off-pump coronary artery bypass, epiaortic ultrasonography identified atherosclerotic findings in the anterior wall of the ascending aorta. This study suggests that revascularization without aortic manipulation during off-pump coronary artery bypass is indicated in as many as 25% of patients.

Adult↗

PubMed2002

Pharmacological analysis for mechanisms of GPI-80 release from tumour necrosis factor-alpha-stimulated human neutrophils.

1 GPI-80, a glycosylphosphatidylinositol (GPI)-anchored protein initially identified on human neutrophils, plays a role(s) in the regulation of beta2 integrin function. Previous studies have shown that GPI-80 is sublocated in secretory vesicles. It is also found in soluble form in the synovial fluid of rheumatoid arthritis patients, and in the culture supernatant of formyl-methionyl-leucyl-phenylalanine-stimulated neutrophils. To understand the behaviour of GPI-80 under conditions of stimulation, we investigated the effects of tumour necrosis factor (TNF)-alpha on its expression and release. We also probed the mechanism of its release with various pharmacologic tools. 2 TNF-alpha induced the release of GPI-80 from human neutrophils in a concentration- and time-dependent manner (in the range of 1-100 u ml(-1) and 30-120 min, respectively), but did not affect surface GPI-80 levels. 3 Cytochalasin B, genistein, and SB203580 but not PD98059 inhibited TNF-alpha-stimulated GPI-80 release and neutrophil adherence at the same concentration. In addition, TNF-alpha-induced GPI-80 release was inhibited by blocking monoclonal antibodies specific to components of Mac-1 (CD11b and CD18). 4 Antioxidants (pyrrolidine dithiocarbamate and N-acetyl-L-cysteine) inhibited GPI-80 release by TNF-alpha stimulation, but superoxide dismutase did not. Antioxidants but not superoxide dismutase reduced an intracellular oxidation state. 5 These findings indicate that TNF-alpha-stimulated GPI-80 release from human neutrophils depends upon adherence via beta2 integrins. They also suggest that cytochalasin B, genistein, and SB203580 inhibit GPI-80 release by suppressing signals for cell adherence, rather than by a direct effect on its secretion. Finally, we suggest that GPI-80 release involves an intracellular change in a redox state.

Amidohydrolases↗

PubMed2002

Global interference: the effect of exposure duration that is substituted for spatial frequency.

In this study, participants were required to identify hierarchically structured patterns that appeared at either global or local level. Paquet and Merikle (1984 Canadian Journal of Psychology 381 45-53) showed that global interference is affected by exposure duration in the processing of a hierarchical structure. They showed that only global-to-local interference occurred at short exposure durations. In contrast, global-to-local as well as local-to-global interference was observed at long exposure durations. They suggested that the effect of exposure duration with global interference depends on the high-spatial-frequency versus low-spatial-frequency channel. In the present study, exposure duration (short or long) was varied randomly from trial to trial (experiment 1), or held constant (experiment 2). In experiment 1, global-to-local interference occurred at both short and long exposure durations, even though the same physical properties existed as in experiment 2. In experiment 2, both global-to-local and local-to-global interference occurred at only long exposure durations, in line with the results reported by Paquet and Merikle. This suggests that the effect of exposure duration on global interference is explained not only by spatial-frequency channels, but also by attentional shift.

Computer Graphics↗

PubMed2002

Inhibitory tagging on randomly moving objects.

Inhibitory tagging is a process that prevents focal attention from revisiting previously checked items in inefficient searches, facilitating search performance. Recent studies suggested that inhibitory tagging is object rather than location based, but it was unclear whether inhibitory tagging operates on moving objects. The present study investigated the tagging effect on moving objects. Participants were asked to search for a moving target among randomly and independently moving distractors. After either efficient or inefficient search, participants performed a probe detection task that measured the inhibitory effect on search items. The inhibitory effect on distractors was observed only after inefficient searches. The present results support the concept of object-based inhibitory tagging.

Adult↗

PubMed2002

Cross-linking of GPI-80, a possible regulatory molecule of cell adhesion, induces up-regulation of CD11b/CD18 expression on neutrophil surfaces and shedding of L-selectin.

Previously, we described a novel glycosylphosphatidyl inositol (GPI)-anchored glycoprotein (designated GPI-80) on human neutrophils and monocytes that may regulate beta(2) integrin-dependent neutrophil adherence and migration. However, the mechanism regulating beta(2) integrin remains to be clarified. To study this, we examined changes in beta(2) integrin expression and function caused by cross-linking GPI-80. GPI-80 cross-linking induced up-regulation of CD11b/CD18 (Mac-1) expression on neutrophil surfaces and shedding of L-selectin, which depends on tyrosine phosphorylation and cytoskeleton remodeling. Furthermore, the cross-linking enhanced fMLP-induced human neutrophil adherence. These results suggest that GPI-80 may be a regulator of beta(2) integrin in neutrophils.

Amidohydrolases↗

PubMed2001

Immunohistochemical localization in human tissues of GPI-80, a novel glycosylphosphatidyl inositol-anchored protein that may regulate neutrophil extravasation.

We molecular-cloned a novel 80-kDa human glycosyl-phosphatidyl inositol (GPI)-anchored protein, designated GPI-80, that may regulate neutrophil extravasation. To identify the possible role of GPI-80 in vivo, we examined the immunohistochemical localization of GPI-80 in various human tissues. Our data show that GPI-80 is mainly located in polymorphonuclear leukocytes (PMNs), endothelial cells of the vessels, parietal cells and mucous neck cells of the stomach, goblet cells of the jejunum, and alveolar macrophages of the lung. The pathomechanisms of these positive findings in the gastric glands and the intestinal glands are not well elucidated and further studies will be needed.

Amidohydrolases↗